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1.  Are Revisions of Patellofemoral Arthroplasties More Like Primary or Revision TKAs 
Background
Patellofemoral arthroplasty (PFA) can be considered in patients with patellofemoral disease. However, the use of partial arthroplasty often causes concern among clinicians and patients that revision to total knee arthroplasty (TKA) will be needed and, if so, whether this revision will be straightforward or more complicated.
Questions/purposes
We set out to determine if conversion of a PFA to a TKA was more similar to a primary or to a revision TKA in terms of surgical characteristics, knee scores, range of motion, and complications.
Methods
Between 2001 and 2008, we revised 21 PFAs to TKAs, all of which were available for followup at a minimum of 5 years (median, 6 years; range, 5–12 years). These patients were matched one-to-one by age, sex, body mass index, length of followup, and preoperative Knee Society Scores (KSS) to 21 primary and 21 revision TKAs. We analyzed operative time and amount of blood loss. Clinical outcomes assessed were range of motion and KSS.
Results
Blood loss (405 mL versus 460 mL versus 900 mL; odds/hazard ratio, 1.33, 95% confidence interval [CI], 0.3–5.85; p = 0.14 for primary TKA versus revision PFA and odds/hazard ratio, 0.13, 95% CI, 0.03–0.52; p < 0.01 for revision PFA versus revision TKA) and operative time (52 minutes versus 72 minutes versus 115 minutes; odds/hazard ratio, 5.45, 95% CI, 1.23–27.4; p = 0.02 for primary TKA versus revision PFA and odds/hazard ratio, 0.5, 95% CI, 0.01–0.44; p < 0.001 for revision PFA versus revision TKA) were not different between the primary TKA and revision PFA groups but higher in the revision TKA group. KSS (knee and function) were higher in the primary TKA group (92 [range, 60–100] and 91 [range, 65–100]) than they were in the revision PFA (85 [range, 40–100] and 85 [range, 30–100]) and revision TKA groups (75 [range, 30–100] and 68 [range, 25–100]; p < 0.001). Flexion was better in the primary TKA (125 [range, 105–130]) and revised PFA (120 [range, 100–130]) groups than the revision TKA group (105 [range, 80–115]; p = 0.0013). There were more complications in the revision PFA group (two of 21) compared with the primary TKA group (zero of 21, p = 0.005) but not compared with the revision TKA group (three of 21; p = 0.85).
Conclusions
With the numbers available, we found that revising a PFA is comparable to a primary TKA in regard to surgical characteristics and postoperative clinical outcomes (including knee scores and range of motion), and both are superior to revision TKA, although the frequency of complications was higher in the revision PFA group than it was in the primary TKA group. The majority of patients undergoing revision of a PFA to a TKA can be treated with a standard implant.
Level of Evidence
Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-014-3756-x
PMCID: PMC4390926  PMID: 24980643
2.  Revision Surgery for Patellofemoral Problems: Should We Always Resurface? 
Background
Routine patellar resurfacing performed at the time of knee arthroplasty is controversial, with some evidence of utility in both TKA (tricompartmental) and bicompartmental knee arthroplasty. However, whether one approach results in better implant survival remains unclear.
Questions/purposes
We asked whether (1) routine patellar resurfacing in TKAs resulted in lower cumulative revision rates compared to bicompartmental knee arthroplasties, (2) patella-friendly implants resulted in lower cumulative revision rates than earlier designs, and (3) bicompartmental knee arthroplasties revised to TKAs had higher cumulative revision rates than primary TKAs.
Patients and Methods
From a community-based joint registry, we identified 8135 patients treated with 9530 cemented, all-polyethylene patella TKAs and 627 bicompartmental knee arthroplasties without patellar resurfacing. We compared age, gender, year of index procedure, diagnosis, cruciate status, revision, and revision reason.
Results
TKAs had a lower cumulative revision rate for patella-only revision than bicompartmental knee arthroplasties (0.8% versus 4.8%). Adjusting for age, bicompartmental knee arthroplasties were 6.9 times more likely to undergo patellar revision than TKAs. There was no difference in the cumulative revision rate for patella-only revisions between patella-friendly and earlier designs. The cumulative revision rate for any second revision after a patella-only revision was 12.7% for bicompartmental knee arthroplasties while that for primary TKAs was 6.3%.
Conclusions
Bicompartmental knee arthroplasties had higher revision rates than TKAs. Femoral component design did not influence the cumulative revision rate. Secondary patella resurfacing in a bicompartmental knee arthroplasty carried an increased revision risk compared to resurfacing at the time of index TKA. To reduce the probability of reoperation for patellofemoral problems, our data suggest the patella should be resurfaced at the time of index surgery.
Level of Evidence
Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-011-2036-2
PMCID: PMC3237992  PMID: 21858641
3.  Total Knee Arthroplasty for Post-Traumatic Proximal Tibial Bone Defect: Three Cases Report 
Bone stock deficiency in primary as well as in revision total knee arthroplasty (TKA) represents a difficult problem to surgeon with regard to maintaining proper alignment of the implant components and in establishing a stable bone-implant interface. Different surgical procedures are available in these situations, for instances the use of bone cement, prosthetic augments, custom implant, and wire mesh with morsellized bone grafting and structural bone allograft. Structural allograft offers a numerous advantages as easy remodeling and felling cavitary or segmental defects, excellent biocompatibility, bone stock restoration and potential for ligamentous reattachment. In this article we report a short term result of three cases affected by severe segmental medial post/traumatic tibial plateau defect in arthritic knee, for which massive structural allograft reconstruction and primary total knee replacement were carried. The heights of the bone defect were between 27-33 mm and with moderate medio-lateral knee instability. Pre-operative AKS score in three cases was 30, 34 and 51 points consecutively and improved at the last follow-up to 83, 78 and 85 consecutively. No acute or chronic complication was observed. Last radiological exam referred no signs of prosthetic loosening, no secondary resorption of bone graft and well integrated graft to host bone. These results achieved in our similar three cases have confirmed that the structural bone allograft is a successful biological material to restore hemi-condylar segmental tibial bone defect when total knee replacement is indicated.
doi:10.2174/1874325001105010143
PMCID: PMC3093746  PMID: 21584202
Tibial bone defect; structural allograft; total knee arthroplasty.
4.  10-year results following impaction bone grafting of major bone defects in 29 rotational and hinged knee revision arthroplasties 
Acta Orthopaedica  2013;84(4):387-391.
Background and purpose
— Substantial bone loss in revision total knee arthroplasty (TKA) is a challenging problem. We studied whether impaction bone grafting provides long-term restoration of bone stock in the treatment of major bone defects in revision surgery of rotational and hinged knee arthroplasties (LINK Endo-Model).
Patients and methods
— Between 1996 and 2006, 29 knees in 29 patients underwent revision procedures of rotational and hinged knee arthroplasties using impaction bone grafting (IBG) to reconstruct major bone defects. At the latest follow-up, the clinical examination included the Knee Society score (KSS), standardized radiographs, and a questionnaire for the WOMAC score.
Results
— After a mean follow-up of 10 (6–13) years, 14 knees with 19 IBG reconstructions (5 total, 9 partial revisions) had failed. 12 knees were treated with re-revision surgery mean 5 (1–12) years after the first revision, due to mechanical failure and aseptic loosening of the components. In all these failed cases, the surgeon observed a lack of incorporation with bone graft resorption in the femur or tibia during the re-revision procedure. In all 15 knees that were not re-revised, with 21 reconstructions (6 total, 9 partial revisions), an improvement in the combined KSS score (knee score + function score) of 60 points (p < 0.001) was found at the latest follow-up. In 12 of these knees, a clear incorporation with no visible radiolucent lines around the component and no sign of substantial graft resorption was noted, while unclear radiographic graft incorporation was seen in 3 knees.
Interpretation
— Our results clearly indicate that IBG alone is not a methodologically sound technique in the revision of rotational and hinged knee arthroplasties.
doi:10.3109/17453674.2013.814012
PMCID: PMC3768039  PMID: 23799350
5.  Causes, Risk Factors, and Trends in Failures After TKA in Korea Over the Past 5 Years: A Multicenter Study 
Background
Failure after total knee arthroplasty (TKA) may be related to emerging technologies, surgical techniques, and changing patient demographics. Over the past decade, TKA use in Korea has increased substantially, and demographic trends have diverged from those of Western countries, but failure mechanisms in Korea have not been well studied.
Questions/purposes
We determined the causes of failure after TKA, the risk factors for failure, and the trends in revision TKAs in Korea over the last 5 years.
Methods
We retrospectively reviewed 634 revision TKAs and 20,234 primary TKAs performed at 19 institutes affiliated with the Kleos Korea Research Group from 2008 to 2012. We recorded the causes of failure after TKA using 11 complications from the standardized complication list of The Knee Society, patient demographics, information on index and revision of TKAs, and indications for index TKA. The influences of patient demographics and indications for index TKA on the risk of TKA failure were evaluated using multivariate regression analysis. The trends in revision procedures and demographic features of the patients undergoing revision TKA over the last 5 years were assessed.
Results
The most common cumulative cause of TKA failure was infection (38%) followed by loosening (33%), wear (13%), instability (7%), and stiffness (3%). However, the incidence of infections has declined over the past 5 years, whereas that of loosening has increased and exceeds that of infection in the more recent 3 years. Young age (odds ratio [OR] per 10 years of age increase, 0.41; 95% confidence interval [CI], 0.37–0.49) and male sex (OR, 1.88; 95% CI, 1.42–2.49) were associated with an increased risk of failure. The percentage of revision TKAs in all primary and revision TKAs remained at approximately 3%, but the annual numbers of revision TKAs in the more recent 3 years increased from that of 2008 by more than 23%.
Conclusions
Despite a recent remarkable increase in TKA use and differences in demographic features, the causes and risk factors for failures in Korea were similar to those of Western countries. Infection was the most common cause of failure, but loosening has emerged as the most common cause in more recent years, which would prompt us to scrutinize the cause and solution to reduce it.
Level of Evidence
Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-013-3252-8
PMCID: PMC3889422  PMID: 23982406
6.  Outcomes of Total Knee Arthroplasty After Osteochondral Allograft Transplantation 
Orthopaedic Journal of Sports Medicine  2014;2(9):2325967114550276.
Background:
Fresh osteochondral allograft (OCA) transplantation is an effective treatment for osteochondral defects. Some patients require further surgical intervention, such as total knee arthroplasty (TKA). The effects of prior OCA transplantation on TKA outcomes are unknown.
Purpose:
This study evaluated TKA failure rates after long-term follow-up and identified factors that may have contributed to an inferior outcome. Its aims were to (1) assess if having a prior OCA transplantation would increase the surgical complications of the subsequent TKA, (2) measure the infection and failure rates following TKA, (3) ascertain subjective outcomes scores from patients with intact TKA at latest follow-up, and (4) identify potential factors that contributed to inferior outcomes.
Study Design:
Case series; Level of evidence, 4.
Methods:
A total of 35 patients who underwent TKA after OCA were identified. Pain, symptoms, function, and quality of life were evaluated using the Knee Society Function score and Knee injury and Osteoarthritis Outcome Score (KOOS). Associations between outcomes scores versus total number of surgeries before TKA were assessed using Spearman correlation. Patient characteristics (age, sex, total OCA area, presentation of osteoarthritis, and number of surgeries before TKA) were calculated between failures and nonfailures.
Results:
For patients with TKA surviving at latest follow-up (n = 24), mean follow-up time was 9.2 ± 4.3 years after TKA and 16.1 ± 5.2 years after OCA. While TKA after OCA did not present a technical challenge in the operating room, there was a high failure rate (31.4%). Activities of daily living, as measured on KOOS, were negatively correlated with total number of surgeries before TKA (ρ2 = –0.5, P = .041). Patient age and number of surgeries before TKA influenced the failure rate, while sex and OCA area did not appear to be factors associated with inferior outcomes.
Conclusion:
Patients with multiple knee operations before TKA were more likely to experience functional limitations or TKA failure. The patients who experienced TKA failure were part of a challenging subset of young patients treated with numerous orthopaedic procedures, and while these patients had inferior results with TKA after OCA, the OCA transplantation extended the time before a TKA was required without adding surgical complications.
doi:10.1177/2325967114550276
PMCID: PMC4555626  PMID: 26535363
osteochondral allograft; total knee arthroplasty; outcomes; revision rates
7.  Results of 32 Allograft-prosthesis Composite Reconstructions of the Proximal Femur 
The use of allograft-prosthesis composites for reconstruction after bone tumor resection at the proximal femur has generated considerable interest since the mid1980s on the basis that their use would improve function and survival, and restore bone stock. Although functional improvement has been documented, it is unknown whether these composites survive long periods and whether they restore bone stock. We therefore determined long-term allograft-prosthesis composite survival, identified major complications that led to revision, and determined whether allograft bone stock could be spared at the time of revision. We also compared the radiographic appearance of allografts sterilized by gamma radiation and fresh-frozen allografts. We retrospectively reviewed 32 patients with bone malignancy in the proximal femur who underwent reconstruction with a cemented allograft-prosthesis composite. The allograft-prosthesis composite was a primary reconstruction for 23 patients and a revision procedure for nine. The minimum followup was 2 months (median, 68 months; range, 2–232 months). The cumulative incidence of revision for any reason was 14% at 5 years (95% confidence interval, 1%–28%) and 19% at 10 years (95% confidence interval, 3%–34%). Nine patients (28%) had revision of the reconstruction during followup; four of these patients had revision surgery for infection. Allografts sterilized by gamma radiation showed worse resorption than fresh-frozen allografts. Based on reported results, allograft-composite prostheses do not appear to improve survival compared with megaprostheses.
Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-009-1132-z
PMCID: PMC2816772  PMID: 19851817
8.  Fresh Osteochondral Allograft Transplantation for Osteochondritis Dissecans of the Knee 
Orthopaedic Journal of Sports Medicine  2014;2(1 Suppl):2325967114S00001.
Objectives:
Osteochondritis dissecans (OCD) of the knee can be difficult to treat. Cartilage restoration techniques are often indicated when the lesion or fragment cannot be salvaged. Fresh osteochondral allograft (OCA) transplantation can restore both bone and cartilage defect as a treatment modality. We hypothesize that osteochondral allografting is a successful method for treating osteochondritis dissecans of the knee.
Methods:
Between 1983 and 2010, 164 patients (181 knees) underwent OCA for OCD of the femoral condyle(s) (type III or IV). Minimum two-year follow-up was available on 149 patients (165 knees). Median age was 25 years (range, 14 to 55) and 73% were male. Mean allograft size was 7.2 cm2(range, 2 to 23 cm2). Evaluation included frequency and type of reoperations, modified Merle d’Aubigné-Postel (18-point) scale, International Knee Documentation Committee (IKDC) pain and function scores, and Knee Society function (KS-F) score. Clinical failure was defined as revision OCA or conversion to arthroplasty. Graft survivorship was determined.
Results:
Median follow-up time was 7.7 years (range, 2 to 28.4 years). 78% had more than 5-year follow-up. Fifty-one of 165 knees (31%) had reoperations, of which 21 (13%) were classified as allograft failures (13 OCA revisions, 5 UKA, and 3 TKA). OCA survivorship was 93% at 5 years, 87% at 10 years, and 77% at 20 years. Of the 144 knees whose grafts were still in situ, 91% were rated good/excellent, 8% were rated fair, and 1% was rated poor. Mean modified Merle d’Aubigné-Postel (18-point) scale was 17, mean IKDC pain and function scores were 2 and 8, and mean KS-F score was 93. 88% of patients reported satisfaction.
Conclusion:
Osteochondral allograft transplantation was an effective treatment for osteochondritis dissecans of the knee, with significant improvement in pain and function scores and high patient satisfaction. Graft survivorship was 87% at 10 years.
doi:10.1177/2325967114S00001
PMCID: PMC4588489
9.  The Risk of Revision After TKA Is Affected by Previous HTO or UKA 
Background
High tibial osteotomy (HTO) and unicompartmental arthroplasty (UKA) are reconstructive surgeries advocated for younger patients. In case of failure or progression of osteoarthritis, they can both be converted to a total knee arthroplasty (TKA).
Questions/purposes
We used registry data to answer if the risks of revision for TKAs after previous HTOs and UKAs differ and how these compare with that of de novo TKAs. Furthermore, we wanted to examine the extent of stemmed/revision implants being used for the conversions.
Methods
We identified HTOs performed during 1998 to 2007 with the help of the inpatient and outpatient care registries of the Swedish National Board of Health and Welfare and gathered relevant information from hospital records. The Swedish Knee Arthroplasty Register was then examined to find all de novo TKAs, TKAs performed after HTO, and TKAs performed after UKA through the end of 2012.
Results
For 920 TKAs after previous UKA and 356 TKAs after previous closed-wedge HTOs, we found the risk of revision significantly higher than for the 118,229 de novo TKAs (risk ratio, 2.8; confidence interval [CI], 2.2–3.5; p < 0.001, and 1.7 CI, 1.1–2.6; p < 0.001, respectively), whereas for the 482 open-wedge osteotomies, the difference was not significant (risk ratio, 1.2; CI, 0.8–1.8; p = 0.44). Stemmed implants were used in 663 of the 117,566 primary de novo TKAs (0.6%), in 22 of the 809 HTO conversions (4%) and in 136 of the 920 UKA conversions (17%).
Conclusions
TKAs after previous reconstructive surgery carry an increased risk for revision. However, our findings do not mitigate against the use of UKA and HTO in selected cases.
Level of Evidence
Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-014-3712-9
PMCID: PMC4390918  PMID: 24898530
10.  Effect of graft choice on the outcome of revision anterior cruciate ligament reconstruction in the Multicenter ACL Revision Study (MARS) Cohort 
Wright, Rick W. | Huston, Laura J. | Haas, Amanda K. | Spindler, Kurt P. | Nwosu, Sam K. | Allen, Christina R. | Anderson, Allen F. | Cooper, Daniel E. | DeBerardino, Thomas M. | Dunn, Warren R. | Lantz, Brett (Brick) A. | Stuart, Michael J. | Garofoli, Elizabeth A. | Albright, John P. | Amendola, Annunziato (Ned) | Andrish, Jack T. | Annunziata, Christopher C. | Arciero, Robert A. | Bach, Bernard R. | Baker, Champ L. | Bartolozzi, Arthur R. | Baumgarten, Keith M. | Bechler, Jeffery R. | Berg, Jeffrey H. | Bernas, Geoffrey A. | Brockmeier, Stephen F. | Brophy, Robert H. | Bush-Joseph, Charles A. | Butler, J. Brad | Campbell, John D. | Carey, James L. | Carpenter, James E. | Cole, Brian J. | Cooper, Jonathan M. | Cox, Charles L. | Creighton, R. Alexander | Dahm, Diane L. | David, Tal S. | Flanigan, David C. | Frederick, Robert W. | Ganley, Theodore J. | Gatt, Charles J. | Gecha, Steven R. | Giffin, James Robert | Hame, Sharon L. | Hannafin, Jo A. | Harner, Christopher D. | Harris, Norman Lindsay | Hechtman, Keith S. | Hershman, Elliott B. | Hoellrich, Rudolf G. | Hosea, Timothy M. | Johnson, David C. | Johnson, Timothy S. | Jones, Morgan H. | Kaeding, Christopher C. | Kamath, Ganesh V. | Klootwyk, Thomas E. | Levy, Bruce A. | Ma, C. Benjamin | Maiers, G. Peter | Marx, Robert G. | Matava, Matthew J. | Mathien, Gregory M. | McAllister, David R. | McCarty, Eric C. | McCormack, Robert G. | Miller, Bruce S. | Nissen, Carl W. | O'Neill, Daniel F. | Owens, Brett D. | Parker, Richard D. | Purnell, Mark L. | Ramappa, Arun J. | Rauh, Michael A. | Rettig, Arthur C. | Sekiya, Jon K. | Shea, Kevin G. | Sherman, Orrin H. | Slauterbeck, James R. | Smith, Matthew V. | Spang, Jeffrey T. | Svoboda, Steven J. | Taft, Timothy N. | Tenuta, Joachim J. | Tingstad, Edwin M. | Vidal, Armando F. | Viskontas, Darius G. | White, Richard A. | Williams, James S. | Wolcott, Michelle L. | Wolf, Brian R. | York, James J.
Background
Most surgeons believe that graft choice for ACL reconstruction is an important factor related to outcome. Although graft choice may be limited in the revision setting based on previously used grafts, it is still felt to be important.
Hypothesis
The purpose of this study was to determine if revision ACL graft choice predicts outcomes related to sports function, activity level, OA symptoms, graft re-rupture, and reoperation at two years following revision reconstruction. We hypothesized that autograft use would result in increased sports function, increased activity level, and decreased OA symptoms (as measured by validated patient reported outcome instruments). Additionally, we hypothesized that autograft use would result in decreased graft failure and reoperation rate 2 years following revision ACL reconstruction.
Study Design
Prospective cohort study; Level of evidence, 2.
Methods
Revision ACL reconstruction patients were identified and prospectively enrolled by 83 surgeons over 52 sites. Data collected included baseline demographics, surgical technique and pathology, and a series of validated patient reported outcome instruments (IKDC, KOOS, WOMAC, and Marx activity rating score). Patients were followed up at 2 years, and asked to complete the identical set of outcome instruments. Incidence of additional surgery and reoperation due to graft failure were also recorded. Multivariate regression models were used to determine the predictors (risk factors) of IKDC, KOOS, WOMAC, Marx scores, graft re-rupture, and reoperation rate at 2 years following revision surgery.
Results
1205 patients were successfully enrolled with 697 (58%) males. Median age was 26. In 88% this was their first revision. 341 (28%) were undergoing revision by the surgeon that had performed the previous reconstruction. 583 (48%) underwent revision reconstruction utilizing an autograft, 590 (49%) allograft, and 32 (3%) both autograft and allograft. Median time since their last ACL reconstruction was 3.4 years. Questionnaire follow-up was obtained on 989 subjects (82%), while phone follow-up was obtained on 1112 subjects (92%). The IKDC, KOOS, and WOMAC scores (with the exception of the WOMAC stiffness subscale) all significantly improved at the two year follow-up time point (p<0.001). In contrast, the two year MARX activity scale demonstrated a significant decrease from the initial score at enrollment (p<0.001).
Graft choice proved to be a significant predictor of 2 year IKDC scores (p=0.017). Specifically, the use of an autograft for revision reconstruction predicted improved score on the IKDC [p=0.045; Odds Ratio (OR) = 1.31; 95% confidence intervals (CI) = 1.01, 1.70]. The use of an autograft predicted an improved on the KOOS subscale Sports and Recreation (p=0.037; OR=1.33; 95% CI=1.02, 1.73). Use of an autograft also predicted improved scores on the KOOS subscale Quality of Life (QOL) (p=0.031; OR=1.33; 95% CI=1.03, 1.73). For the KOOS Symptoms and ADL subscales, graft choice did not predict outcome score. Graft choice also proved to be a significant predictor of 2 year Marx activity level scores (p=0.012).
Graft re-rupture was reported in 37/1112 (3.3%) of patients by their two year follow-up: 24 allografts, 12 autografts, and 1 allograft + autograft. Use of an autograft for revision resulted in patients 2.78 times less likely to sustain a subsequent graft rupture than if an allograft was utilized (p=0.047; 95% CI=1.01, 7.69).
Conclusions
Improved sports function and patient reported outcome measures are obtained when an autograft is utilized. Additionally, use of an autograft shows a decreased risk in graft re-rupture at two years follow-up. No differences were noted in rerupture or patient reported outcomes between soft tissue and bone-patellar tendon-bone grafts. Surgeon education regarding the findings in this study can result in potentially improved revision ACL reconstruction results for our patients.
doi:10.1177/0363546514549005
PMCID: PMC4447184  PMID: 25274353
Anterior Cruciate Ligament; ACL Revision; Graft; Outcomes
11.  Does a Cemented Cage Improve Revision THA for Severe Acetabular Defects? 
Background
Evidence suggests a growing incidence of revision total hip arthroplasty (THA) including a subset with large acetabular defects. Revision THA for severe acetabular bone loss is associated with a relatively high rate of mechanical failure.
Questions/purposes
We questioned whether cementing a cage to the reconstructed acetabular defect and pelvis would improve the rate of mechanical failure for patients with Type 3 defects (Paprosky et al.) with and without pelvic discontinuity in comparison to historical controls.
Methods
We retrospectively collected data on 33 patients who underwent 35 revision THAs using an acetabular reconstruction cage cemented to morselized allograft and either structural allograft or trabecular metal augmentation for Type 3 defects in the presence (n = 13) and absence (n = 22) of pelvic discontinuity at a mean followup of 59 months (range, 24–92 months). The primary outcome was mechanical failure, defined as revision of the acetabular reconstruction for aseptic loosening.
Results
Revision surgery for mechanical failure occurred in four of the 13 patients with pelvic discontinuity and two of the 22 patients without discontinuity. Radiographic loosening occurred in one patient with and one patient without pelvic discontinuity. Seven of the 35 revisions were subsequently revised for deep infection all in patients who were immunocompromised.
Conclusions
Cementing the cage to the pelvis can offer an advantage for treating severe acetabular defects. Trabecular metal augmentation appears to provide better initial mechanical stability than a structural allograft, but successful allograft reconstruction may restore bone stock.
Level of Evidence
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-010-1546-7
PMCID: PMC3018232  PMID: 20857251
12.  Does a Cemented Cage Improve Revision THA for Severe Acetabular Defects? 
Background
Evidence suggests a growing incidence of revision total hip arthroplasty (THA) including a subset with large acetabular defects. Revision THA for severe acetabular bone loss is associated with a relatively high rate of mechanical failure.
Questions/purposes
We questioned whether cementing a cage to the reconstructed acetabular defect and pelvis would improve the rate of mechanical failure for patients with Type 3 defects (Paprosky et al.) with and without pelvic discontinuity in comparison to historical controls.
Methods
We retrospectively collected data on 33 patients who underwent 35 revision THAs using an acetabular reconstruction cage cemented to morselized allograft and either structural allograft or trabecular metal augmentation for Type 3 defects in the presence (n = 13) and absence (n = 22) of pelvic discontinuity at a mean followup of 59 months (range, 24–92 months). The primary outcome was mechanical failure, defined as revision of the acetabular reconstruction for aseptic loosening.
Results
Revision surgery for mechanical failure occurred in four of the 13 patients with pelvic discontinuity and two of the 22 patients without discontinuity. Radiographic loosening occurred in one patient with and one patient without pelvic discontinuity. Seven of the 35 revisions were subsequently revised for deep infection all in patients who were immunocompromised.
Conclusions
Cementing the cage to the pelvis can offer an advantage for treating severe acetabular defects. Trabecular metal augmentation appears to provide better initial mechanical stability than a structural allograft, but successful allograft reconstruction may restore bone stock.
Level of Evidence
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-010-1546-7
PMCID: PMC3018232  PMID: 20857251
13.  How Do Knee Implants Perform Past the Second Decade? Nineteen- to 25-year Followup of the Press-fit Condylar Design TKA 
Background
At 14- to 17-year followup, we reported successful outcomes of the Press-fit Condylar total knee arthroplasty (TKA) system in 160 TKAs performed between 1986 and 1989. However, there are few published reports on TKA survivorship and patient function that include patients evaluated into the third decade after surgery.
Questions/purposes
The study purpose was to determine (1) the survivorship of the implant; and (2) knee function in patients with this TKA system at a mean 20-year followup.
Methods
We ascertained revision status of all living patients (42 of 160 knees) and all patients (22 knees) who died since the previous study. Among patients alive at the latest followup, Knee Society function scores were obtained and radiographs were evaluated. Kaplan-Meier survivorship analysis with 95% confidence intervals was performed with revision for any reason and aseptic loosening as endpoints. A competing risks analysis with 95% confidence intervals was also performed for revision for any reason as the endpoint.
Results
At the mean 20-year (range, 19–25 years) followup, all living patients retained their original implants from the index TKA, exclusive of three polyethylene exchanges. This study demonstrates an 87% Kaplan-Meier survivorship for revision for any reason (95% confidence interval [CI], 80%–92%) and a 98% Kaplan-Meier survivorship for revision for aseptic loosening (95% CI, 93%–99%). Competing risks survivorship was 79% (95% CI, 70%–85%) at 25 years for revision for any reason. Mean Knee Society function score was 46.9. Since the previous study, three revisions have been performed, all for polyethylene wear.
Conclusions
The Press-fit Condylar implant system continues to be successful, maintaining longevity up to 25-year followup. This is one of the longest followup studies, reporting continued successes over 20 years, and should serve as a benchmark for current-generation implants.
Level of Evidence
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-014-3792-6
PMCID: PMC4390935  PMID: 25082622
14.  Is There a Difference in Total Knee Arthroplasty Risk of Revision in Highly Crosslinked versus Conventional Polyethylene? 
Background
Highly crosslinked polyethylene (HXLPE) was introduced to reduce wear and associated osteolysis in total knee arthroplasty (TKA). However, there is limited clinical evidence that HXLPE is more effective than conventional polyethylene (CPE) in TKA.
Questions/purposes
(1) Do primary TKAs with HXLPE tibial inserts have a lower risk of revision (all-cause, aseptic, and septic) than TKAs with CPE tibial inserts? (2) In NexGen TKA (Zimmer Inc, Warsaw, IN, USA) bearings, do HXLPE tibial inserts have a lower risk of revision (all-cause, aseptic, and septic) than CPE tibial inserts? (3) In Press-Fit Condylar TKA (PFC or PFC Sigma; DePuy Inc, Warsaw, IN, USA), do HXLPE tibial inserts have a lower risk of revision (all-cause, aseptic, and septic) than procedures performed with CPE tibial inserts?
Methods
The Kaiser Permanente Total Joint Replacement Registry was used to identify primary TKAs (N = 77,084) performed during the study period (April 2001 to December 2011) with cobalt-chromium alloy on CPE (CoCr-CPE) and CoCr-HXLPE bearings. The registry has 95% voluntary participation and less than 9% were loss to followup during the 10-year study period. A total of 60,841 (79%) had CoCr-CPE bearings, 11,048 (14%) had CoCr-HXLPE bearings, and 5195 (7%) were unknown. Specific knee implant designs (NexGen, Zimmer and PFC-Sigma, DePuy Inc) were also evaluated. These implants represented 41% (31,793) and 49% (37,457), respectively, of the 77,084 TKAs of known implant types registered during that period; implant selection was at the discretion of the attending surgeon. Descriptive statistics and marginal Cox regression models with propensity score adjustments were applied to compare risk of revision for CoCr-CPE versus CoCr-HXLPE TKA bearings.
Results
At 5 years followup, cumulative incidence of revision for CoCr-CPE and CoCr-XLPE were 2.7% and 3.1%, respectively. Adjusted risks of all-cause (hazard ratio [HR], 1.05; 95% confidence interval [CI], 0.86–1.29; p = 0.620), aseptic (HR, 1.01; 95% CI, 0.77–1.32; p = 0.954), and septic revision (HR, 1.11; 95% CI, 0.81–1.51; p = 0.519) did not differ in patients with CoCr-XLPE bearings compared with CoCr-CPE. Within TKAs with NexGen components, the adjusted risks of all-cause (HR, 1.14; 95% CI, 0.86–1.51; p = 0.354), aseptic (HR, 1.14; 95% CI, 0.79–1.65; p = 0.493), and septic revision (HR, 1.14; 95% CI, 0.76–1.73; p = 518) were similar in patients with CoCr-XLPE compared with those with CoCr-CPE bearings. Finally, within the TKAs with PFC components, the adjusted risks of all-cause (HR, 0.80; 95% CI, 0.49–1.30; p = 0.369), aseptic (HR, 0.62; 95% CI, 0.62–1.14; p = 0.123), and septic revision (HR, 0.97; 95% CI, 0.51–1.85; p = 0.929) were also similar in patients with CoCr-XLPE compared with those with CoCr-CPE bearings.
Conclusions
In this large study, we did not find differences in risk of revision for CoCr-HXLPE compared with CoCr-CPE bearings at 5 years followup. In selecting HXLPE in TKA, clinicians should consider the increased cost and lack of available evidence of performance for greater than 10 years followup. Future studies are necessary to evaluate longitudinal outcomes of CoCr-HXLPE versus conventional TKA bearings.
Level of Evidence
Level III, therapeutic study.
doi:10.1007/s11999-014-4046-3
PMCID: PMC4317427  PMID: 25567357
15.  Joint line and patellar height restoration after revision total knee arthroplasty 
Indian Journal of Orthopaedics  2016;50(2):159-165.
Background:
Restoration of proper joint line (JL) position and patellar height in revision total knee arthroplasty (TKA) is essential in the recovery of knee function and kinematics. We determined whether the JL position and patellar height could be restored in patients undergoing septic and aseptic revision TKA.
Materials and Methods:
We retrospectively reviewed 70 patients (74 knees) who had revision TKA between September 2004 and December 2010. Forty seven knees had a two stage revision for infected TKA and 27 knees for aseptic failure. The JL position, patellar height and patellar tendon (PT) length were measured and compared between primary TKA and post revision. The clinical scores including a hospital for special surgery (HSS), Knee Society Score (KSS), Western Ontario and McMaster Universities (WOMAC) and range of motion (ROM) were compared.
Results:
The overall JL increased from 17.51 mm to 18.37 mm post revision, the Insall-Salvati (IS) ratio declined from 0.98 to 0.92, and the PT length declined from 42.92 mm to 39.45 mm. 9 of the 21 patellar baja knees improved to normal patellar height. After revision, the JL in the septic group (17.02 mm) was significantly lower than the aseptic group (20.74 mm). The changes of the JL position and IS ratio in the septic group were significantly larger than the aseptic groups (P < 0.05). JL position had a positive correlation to the IS ratio and PT length post revision. The knee function scores including HSS, KSS, WOMAC scores, and ROM all improved post revision compared to pre revision (P < 0.05), and the septic group had a lower knee function compared to the aseptic group. JL position and IS ratio post revision had no correlation to the HSS, KSS, WOMAC scores, and ROM.
Conclusions:
JL position can be sufficiently restored with appropriate distal femoral augment reconstruction after revision TKA, but the patellar height cannot be well improved, especially in the septic revision with obvious PT contracture. No correlation was found between the JL position and patellar height to the knee function post revision TKA.
doi:10.4103/0019-5413.177569
PMCID: PMC4800958  PMID: 27053805
Joint line; knee function; patellar height; revision; total knee arthroplasty; Arthroplasty; replacement; knee; osteoarthritis; knee prosthe
16.  Osteogenic Protein-1 for Long Bone Nonunion 
Executive Summary
Objective
To assess the efficacy of osteogenic protein-1 (OP-1) for long bone nonunion.
Clinical Need
Although most fractures heal within a normal period, about 5% to 10% do not heal and are classified as delayed or nonunion fractures. Nonunion and segmental bone loss after fracture, reconstructive surgery, or lesion excision can present complex orthopedic problems, and the multiple surgical procedures often needed are associated with patient morbidity and reduced quality of life.
Many factors contribute to the pathogenesis of a delayed union or nonunion fractures, including deficiencies of calcium, vitamin D, or vitamin C, and side effects of medications such as anticoagulants, steroids, some anti-inflammatory drugs, and radiation. It has been shown that smoking interferes with bone repair in several ways.
Incidence of Nonunion and Delayed Union Cases
An estimated 5% to 10% of fractures do not heal properly and go on to delayed union or nonunion. If this overall estimate of incidence were applied to the Ontario population1, the estimated number of delayed union or nonunion in the province would be between 3,863 and 7,725.
Treatment of Nonunion Cases
The treatment of nonunion cases is a challenge to orthopedic surgeons. However, the basic principle behind treatment is to provide both mechanical and biological support to the nonunion site.
Fracture stabilization and immobilization is frequently used with the other treatment modalities that provide biological support to the fractured bone. Biological support includes materials that could be served as a source of osteogenic cells (osteogenesis), a stimulator of mesenchymal cells (osteoinduction), or a scaffold-like structure (osteoconduction).
The capacity to heal a fracture is a latent potential of the stromal stem cells, which synthesize new bone. This process has been defined as osteogenesis. Activation of the stem cells to initiate osteogenic response and to differentiate into bone-forming osteoblasts is called osteoinduction. These 2 properties accelerate the rate of fracture healing or reactivate the ineffective healing process. Osteoconduction occurs when passive structures facilitate the migration of osteoprogenitor cells, the perivascular tissue, and capillaries into these structures.
Bone Grafts and Bone Graft Substitutes
Bone graft and bone graft substitutes have one or more of the following components:
Undifferentiated stem cells
Growth factors
Structural lattice
Undifferentiated stem cells are unspecialized, multipotential cells that can differentiate into a variety of specialized cells. They can also replicate themselves. The role of stem cells is to maintain and repair the tissue in which they are residing. A single stem cell can generate all cell types of that tissue. Bone marrow is a source of at least 2 kinds of stem cells. Hematopoietic stem cells that form all types of blood cells, and bone marrow stromal stem cells that have osteogenic properties and can generate bone, cartilage, and fibrous tissue.
Bone marrow has been used to stimulate bone formation in bone defects and cases of nonunion fractures. Bone marrow can be aspirated from the iliac crest and injected percutaneously with fluoroscopic guidance into the site of the nonunion fracture. The effectiveness of this technique depends on the number and activity of stem cells in the aspirated bone marrow. It may be possible to increase the proliferation and speed differentiation of stem cells by exposing them to growth factor or by combining them with collagen.
Many growth factors and cytokines induced in response to injury are believed to have a considerable role in the process of repair. Of the many bone growth factors studied, bone morphogenetics (BMPs) have generated the greatest attention because of their osteoinductive potential. The BMPs that have been most widely studied for their ability to induce bone regeneration in humans include BMP-2 and BMP-7 (osteogenic protein). Human osteogenic protein-1 (OP-1) has been cloned and produced with recombinant technology and is free from the risk of infection or allergic reaction.
The structural lattice is osteoconductive; it supports the ingrowth of developing capillaries and perivascular tissues. Three distinct groups of structural lattice have been identified: collagen, calcium sulphate, and calcium phosphate. These materials can be used to replace a lost segment of bone.
Grafts Used for Nonunion
Autologous bone graft is generally considered the gold standard and the best material for grafting because it contains several elements that are critical in promoting bone formation, including osteoprogenitor cells, the matrix, and bone morphogenetic proteins. The osteoconductive property of cancellous autograft is related to the porosity of bone. The highly porous, scaffold-like structure of the graft allows host osteoblasts and host osteoprogenitor cells to migrate easily into the area of the defect and to begin regeneration of bone. Sources of cancellous bone are the iliac crest, the distal femur, the greater trochanter, and the proximal tibia. However, harvesting the autologous bone graft is associated with postoperative pain at the donor site, potential injury to the surrounding arteries, nerves, and tissues, and the risk of infection. Thus the development of synthetic materials with osteoconductive and osteoinductive properties that can eliminate the need for harvesting has become a major goal of orthopedic research.
Allograft is the graft of tissue between individuals who are of the same species but are of a disparate genotype. Allograft has osteoconductive and limited osteoinductive properties. Demineralized bone matrix (DBM) is human cortical and cancellous allograft. These products are prepared by acid extraction of allograft bone, resulting in the loss of most of the mineralized component while collagen and noncollagenous proteins, including growth factors, are retained. Figures 1 to 5 demonstrate the osteogenic, osteoinduction, and osteoconduction properties of autologous bone graft, allograft, OP-1, bone graft substitutes, and bone marrow.
Autologous Bone Graft
Osteogenic Protein-1
Allograft bone and Demineralized Bone Matrix
Bone Graft Substitutes
Autologous Bone Marrow Graft
New Technology Being Reviewed: Osteogenic Protein-1
Health Canada issued a Class IV licence for OP-1 in June 2004 (licence number 36320). The manufacturer of OP-1 is Stryker Biotech (Hapkinton, MA).
The United States Food and Drug Administration (FDA) issued a humanitarian device exemption for the application of the OP-1 implant as an “alternative to autograft in recalcitrant long bone nonunions where use of autograft is unfeasible and alternative treatments have failed.” Regulatory agencies in Europe, Australia, and New Zealand have permitted the use of this implant in specific cases, such as in tibial nonunions, or in more general cases, such as in long bone nonunions.
According to the manufacturer, OP-1 is indicated for the treatment of long bone nonunions. It is contraindicated in the patient has a hypersensitivity to the active substance or collagen, and it should not be applied at the site of a resected tumour that is at or near the defect or fracture. Finally, it should not be used in patients who are skeletally immature (< 18 years of age), or if there is no radiological evidence of closure of epiphysis.
Review Strategy
Objective
To summarize the safety profile and effectiveness of OP-1 in the treatment of cases of long bone nonunion and bone defects
To compare the effectiveness and cost effectiveness of OP-1 in the treatment of long bone nonunions and bone defects with the alternative technologies, particularly the gold standard autologous bone graft.
Literature Search
International Network of Agencies for Health Technology Assessments (INAHTA), the Cochrane Database of Systematic Reviews and the CCTR (formerly Cochrane Controlled Trials Register) were searched for health technology assessments. MEDLINE, EMBASE, Medline In Process and Other Non-Indexed Citations were searched from January 1, 1996 to January 27, 2004 for studies on OP-1. The search was limited to English-language articles and human studies. The search yielded 47 citations. Three studies met inclusion criteria (2 RCTs and 1 Ontario-based study presented at an international conference.
Summary of Findings
Friedlaender et al. conducted a prospective, randomized, partially blinded clinical trial on the treatment tibial nonunions with OP-1. Tibial nonunions were chosen for this study because of their high frequency, challenging treatment requirements, and substantial morbidity. All of the nonunions were at least 9 months old and had shown no progress toward healing over the previous 3 months. The patients were randomized to receive either treatment with autologous bone grafting or treatment with OP-1 in a type-1 collagen carrier. Both groups received reduction and fixation with an intramedullary rod. Table 1 summarizes the clinical outcomes of this study.
Outcomes in a Randomized Clinical Trial on Tibial Nonunions: Osteogenic Protein-1 versus Autologous Bone Grafting
Clinical success was defined as full weight-bearing, loss of severe pain at the fracture site on weight-bearing, and no further surgical treatment to enhance fracture repair.
The results of this study demonstrated that recombinant OP-1 is associated with substantial clinical and radiographic success for the treatment of tibial nonunions when used with intramedullary rod fixation. No adverse event related to sensitization was reported. Five per cent of the patients in the OP-1 group had circulating antibodies against type 1 collagen. Only 10% of the patients had a low level of anti-OP-1 antibodies, and all effects were transient. Furthermore, the success rate with the OP-1 implant was comparable with those achieved with autograft at 9 and 24 months follow-up. Eighty-two per cent of patients were successful at 24 months follow-up in both groups.
Statistically significant increased blood loss in the group treated with the autograft was observed (P = .049). Patients treated with autograft had longer operation and hospitalization times. All patients in the autograft group had pain at the donor site after surgery, and more than 80% judged their postoperative pain as moderate or severe. At their 6-month visit, 20% of the patients in the autograft group had persistent pain, mild or moderate in nature, at the donor site. This number fell to 13% at 12 months.
All patients in each of the groups had at least 1 adverse event that wasn’t serious, such as fever, nausea and vomiting, leg edema, discomfort, and bruising at the operative site. The incidence of these events was similar in both groups. Serious adverse events were observed in 44% of both groups, none of which were considered related to the OP-1 implant or autograft.
On the basis of this data, the FDA issued a humanitarian device exemption for the application of OP-1 implant as an alternative to autograft in recalcitrant long bone nonunions when the use of autograft is unfeasible and alternative treatments have failed.
Study on Fibular Defects
Geesink et al. investigated the osteogenic activity of OP-1 by assessing its value in bridging fibular defects made at the time of tibial osteotomy for varus or valgus deformity of the knee. This study had 2 phases and included 12 patients in each phase. Each phase included 12 patients (6 in each group). Patients in the first phase received either DBM or were left untreated. Patients in the second phase received either OP-1 on collagen type-1 or collagen type-1 alone.
Radiological and Dual Energy X-ray Absorptiometry (DEXA) evaluation showed that in patients in whom the defect was left untreated, no formation of bone occurred. At 12 months follow-up, new bone formation with bridging occurred in 4 of the 6 patients in DMB group, and 5 of the 6 patients in OP-1 group. One patient in OP-1 group did not show any evidence of new bone formation at any point during the study.
Ontario Pilot Study
A prospective pilot study was conducted in Ontario, Canada to investigate the safety and efficacy of OP-1 for the treatment of recalcitrant long bone nonunions. The study looked at 15 patients with complex, recalcitrant, long bone nonunions whose previous treatment had failed. The investigators concluded that this bone graft substitute appears to be safe and effective in providing sufficient biological stimulation in difficult to treat nonunions. Results of a more complete study on 70 patients are ready for publication. According to the principal investigator, OP-1 was 90% effective in inducing bone formation and bone healing in this sample.
Alternative Technologies
The Medical Advisory Secretariat conducted a literature search from January 1, 2000 to February 28, 2005 to identify studies on nonunions/bone defects that had been treated with alternative technologies. A review of these studies showed that, in addition to the gold standard autologous bone marrow grafting, bone allografts, demineralized bone matrices, bone graft substitutes, and autologous bone marrow have been used for treatment of nonunions and bone defects. These studies were categorized according to the osteoinductive, osteoconductive, and osteogenesis properties of the technologies studied.
A review of these studies showed that bone allografts have been used mostly in various reconstruction procedures to restore the defect after excavating a bone lesion. Two studies investigated the effectiveness of DBM in healing fracture nonunions. Calcium phosphate and calcium sulphate have been used mostly for repair of bone defects.
Several investigators have looked at the use of autologous bone marrow for treatment of long bone nonunions. The results of these studies show that method of percutaneous bone marrow grafting is highly effective in the treatment of long bone nonunions. In a total of 301 fractures across all studies, 268 (89%) healed with a mean healing time of 2.5 to 8 months. This healing time as derived from these case series is less than the timing of the primary end point in Friedlaender’s study (9 months). Table 2 summarizes the results of these studies. Table 2 summarizes the results of these studies.
Studies that used Percutaneous Bone Marrow Grafting for Treatment of Nonunions
Economic Analysis
Based on annual estimated incidence of long-bone nonunion of 3,863 - 7,725, the annual hospitalization costs associated with this condition is between $21.2 and $42.3 million based on a unit cost of $5,477 per hospital separation. When utilized, the device, a single vial of OP-1, is approximately $5,000 and if adopted universally in Ontario, the total device costs would be in the range of $19.3 - $38.6 million annually. The physician fee for harvest, insertion of bone, or OP-1 is $193 and is $193 for autologous bone marrow transplantation. Total annual physician costs are expected to be in the range of from $0.7 million to $1.3 million per year. Expenditures associated with long-bone nonunion are unlikely to increase since incidence of long-bone nonunion is unlikely to change in the future. However, the rate of uptake of OP-1 could have a significant impact on costs if the uptake were large.
The use of OP-1 and autologous bone marrow transplantation may offset pain medication costs compared with those associated with autologous bone harvest given that the former procedures do not involve the pain associated with the bone harvest site. However, given that this pain is normally not permanent, the overall offset is likely to be small. There are likely to be smaller OHIP costs associated with OP-1 than bone-harvest procedures given that only 1, rather than 2, incisions are needed when comparing the former with the latter procedure. This offset could amount to between $0.3 million to $0.7 million annually.
No data on the cost-effectiveness of OP-1 is available.
PMCID: PMC3382627  PMID: 23074475
17.  What Are the Functional Results and Complications From Allograft Reconstruction After Partial Hemipelvectomy of the Pubis? 
Background
In patients undergoing hemipelvectomies including resection either of a portion of the pubis or the entire pubis from the symphysis to the lateral margin of the obturator foramen while sparing the hip (so-called Dunham Type III hemipelvectomies), reconstructions typically are not performed given the preserved continuity of the weightbearing axis and the potential complications associated with reconstruction. Allograft reconstruction of the pelvic ring may, however, offer benefits for soft tissue reconstruction of the pelvic floor and hip stability, but little is known about these reconstructions.
Questions/purposes
(1) What is the postoperative functional status after allograft reconstruction of Type III pelvic defects? (2) What are the rates of hernia, infection, and hip instability?
Methods
In this case series, we reviewed all patients with Type III pelvic resections (with or without anterior acetabular wall resections) who underwent allograft reconstruction between 2005 and 2013 at one center (N = 14). During the period in question, reconstruction was the general approach used in patients undergoing these resections; during that time, three other patients were treated without reconstruction as a result of either surgeon preference or the patient choosing to not have reconstruction after a discussion of the risks and benefits. Of the 14 patients treated with reconstruction, complete followup was available at a minimum of 1 year in 11 (other than those who died before the end of the first year; median, 19 months; range 16–70 months among those surviving), one was lost to followup before a year, and two others had partial telephone or email followup. Patient demographics, disease status, functional status, and complications were recorded. For a portion of the cohort (four patients) later in the series, we used a novel technique for anterior acetabular wall reconstruction using the concave cartilaginous surface of a proximal fibula allograft; the others received either a long bone (humerus or femur) or hemipelvis graft. Seven patients died of disease; two had local recurrence, and five died of metastatic disease.
Results
All patients remained ambulatory Pain at 12 months after surgery was reported as none in five, mild in two, moderate in two, and severe in one. Operative complications included infection in two, symptomatic hernia in one, hip instability in one, dislocated total hip arthroplasty on the first postoperative day in one, and graft failure in one.
Conclusions
Allograft reconstruction after Type III pelvic resections can provide functional reconstruction of the pelvic ring, pelvic floor, and, in certain patients with partial anterior acetabular resections, the resected anterior acetabulum. This has implications in preventing the occurrence of hernia and hip instability in this patient population that is classically not reconstructed, although longer-term outcomes in a larger number of patients would help to better delineate this because infection, hernia, hip instability, and graft nonunion still remain concerns with this approach. The most important unanswered question remains whether, on balance, any benefits that may accrue to these patients as the result of reconstruction are offset by a relatively high likelihood of undergoing secondary or revision surgery.
Level of Evidence
Level IV, therapeutic study.
doi:10.1007/s11999-014-4009-8
PMCID: PMC4353538  PMID: 25337979
18.  Cementless Revision TKA with Bone Grafting of Osseous Defects Restores Bone Stock with a Low Revision Rate at 4 to 10 years 
Background
Addressing bone loss in revision TKA is challenging despite the array of options to reconstruct the deficient bone. Biologic reconstruction using morselized loosely-packed bone graft potentially allows for augmentation of residual bone stock while offering physiologic load transfer. However it is unclear whether the reconstructions are durable.
Questions/purposes
We therefore sought to determine (1) survivorship and complications, (2) function, and (3) radiographic findings of cementless revision TKA in combination with loosely-packed morselized bone graft to reconstruct osseous defects at revision TKA.
Patients and Methods
We retrospectively reviewed 56 patients who had undergone revision TKAs using cementless long-stemmed components in combination with morselized loose bone graft at our institution. There were 26 men and 30 women with a mean age of 68.3 years (range, 56–89 years). Patients were followed to assess symptoms and function and to detect radiographic loosening, component migration, and graft incorporation. The minimum followup was 4 years (mean, 7.3 years; range, 4–10 years).
Results
Cumulative prosthesis survival, with revision as an end point, was 98% at 10 years. The mean Oxford Knee Scores improved from 21 (36%) preoperatively to 41 (68%) at final followup. Five patients (9%) had reoperations for complications.
Conclusions
Our observations suggest this technique is reproducible and obviates the need for excessive bone resection, use of large metal augments, mass allografts, or custom prostheses. It allows for bone stock to be reconstructed reliably with durable midterm component fixation.
Level of Evidence
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-011-1938-3
PMCID: PMC3183215  PMID: 21678098
19.  Revision Total Knee Arthroplasty for Aseptic and Septic Causes in Patients with Rheumatoid Arthritis 
Revision total knee arthroplasty in patients with rheumatoid arthritis can be challenging. We asked whether we could confirm previously reported high failure rates following revision total knee arthroplasty in patients with rheumatoid arthritis. We therefore determined the Knee Society knee score and function scores, radiographic evidence of failure, and overall survival of the revision procedure in these patients. We retrospectively reviewed 39 patients with rheumatoid arthritis who underwent 45 TKA revisions from 1994 to 2006. Twenty-seven of the 45 TKA revisions were for mechanical failure of the prosthetic components and 18 for infection. Five of the 27 knees (19%) revised for mechanical failure subsequently failed a second time. Five of the 18 patients who underwent revision for infection died within 6 months and three of the remaining knees failed secondary to reinfection. Excluding the knees that failed, the average Knee Society knee score and function score improved in both subgroups. Two knees had radiographic evidence of nonprogressive tibial radiolucencies. The probability of survival for all knees (revision as the end point) was 76% ± 9% at 5 years. We confirmed the previously reported high mortality and subsequent failure rates following revision total knee arthroplasty for both mechanical issues and infection in patients with rheumatoid arthritis and emphasize the potential difficulties in treating these patients.
Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-009-1061-x
PMCID: PMC2795816  PMID: 19727993
20.  ACL reconstruction with BPTB autograft and irradiated fresh frozen allograft*  
Objective: To analyze the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction with irradiated bone-patellar tendon-bone (BPTB) allograft compared with non-irradiated allograft and autograft. Methods: All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 mrad of irradiation prior to distribution. A total of 68 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into one of the two groups (autograft and irradiated allograft groups). The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months of follow-up (ranging from 24 to 47 months), patients were evaluated by the same observer according to objective and subjective clinical evaluations. Results: Of these patients, 65 (autograft 33, irradiated allograft 32) were available for full evaluation. When the irradiated allograft group was compared to the autograft group at the 31-month follow-up by the Lachman test, the anterior drawer test (ADT), the pivot shift test, and KT-2000 arthrometer test, statistically significant differences were found. Most importantly, 87.8% of patients in the autograft group and just only 31.3% in the irradiated allograft group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%). The anterior and rotational stabilities decreased significantly in the irradiated allograft group. According to the overall International Knee Documentation Committee (IKDC), functional and subjective evaluations, and activity level testing, no statistically significant differences were found between the two groups. Besides, patients in the irradiated allograft group had a shorter operation time and a longer duration of postoperative fever. When the patients had a fever, the laboratory examinations of all patients were almost normal. Blood routine was normal, the values of erythrocyte sedimentation rate (ESR) were 5~16 mm/h and the contents of C reactive protein (CRP) were 3~10 mg/L. Conclusion: We conclude that the short term clinical outcomes of the ACL reconstruction with irradiated BPTB allograft were adversely affected. The less than satisfactory results led the senior authors to discontinue the use of irradiated BPTB allograft in ACL surgery and not to advocate using the gamma irradiation as a secondary sterilizing method.
doi:10.1631/jzus.B0820335
PMCID: PMC2666208  PMID: 19353750
Anterior cruciate ligament (ACL) reconstruction; Patellar tendon; Autograft; Allograft; Irradiation; Prospective randomized study
21.  Liner Exchange and Bone Grafting: Rare Option to Treat Wear & Lysis of Stable TKAs 
Background
Liner exchange and bone grafting are commonly performed for wear and osteolysis around well-fixed modular acetabular components that otherwise would require structural allografting and revision THA. However, liner exchange in the face of substantial lysis around TKA has been performed rarely with reports of failure rates of up to 25% at 3 year followup.
Questions/purposes
We therefore evaluated the technique of liner exchange and bone grafting for cases of wear and extensive osteolysis around TKAs in which the components were well-fixed and well-aligned to determine (1) rerevision rates; (2) fate of the bone graft; (3) radiographic loosening rates; and (4) functional scores.
Methods
We retrospectively reviewed 22 patients (25 knees) who underwent revision TKA with exchange of the modular polyethylene insert and bone grafting in cases with well-fixed components and large areas of osteolysis (up to 54 cm2 on a single projection) at the time of revision. The average area of osteolysis was 21 cm2 and 10 cm2 on the AP projection of the femur and tibia, respectively. On the lateral projection, the average area of osteolysis for the femur and tibia was 22 cm2 and 9.3 cm2. Minimum clinical and radiographic followup was 22 and 22 months (average, 61 and 59; range, 22–142 and 22–130, respectively).
Results
One of the 25 knees was revised for aseptic loosening or recurrence of osteolysis. On radiographs, 84.6% and 70% of femoral and tibial osteolytic lesions, respectively, showed evidence of complete or near complete graft incorporation. The remaining lesions showed evidence of partial graft incorporation with the exception of one tibial lesion, which was in the revised case. All other components were well fixed with no evidence of radiographic loosening.
Conclusions
In this selected series of cases with extensive osteolysis around well-fixed and well-aligned TKAs, liner exchange and bone grafting provided durable midterm results with extensive graft incorporation.
Level of Evidence
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-010-1521-3
PMCID: PMC3008882  PMID: 20809171
22.  Revision Rates after Primary Hip and Knee Replacement in England between 2003 and 2006 
PLoS Medicine  2008;5(9):e179.
Background
Hip and knee replacement are some of the most frequently performed surgical procedures in the world. Resurfacing of the hip and unicondylar knee replacement are increasingly being used. There is relatively little evidence on their performance. To study performance of joint replacement in England, we investigated revision rates in the first 3 y after hip or knee replacement according to prosthesis type.
Methods and Findings
We linked records of the National Joint Registry for England and Wales and the Hospital Episode Statistics for patients with a primary hip or knee replacement in the National Health Service in England between April 2003 and September 2006. Hospital Episode Statistics records of succeeding admissions were used to identify revisions for any reason. 76,576 patients with a primary hip replacement and 80,697 with a primary knee replacement were included (51% of all primary hip and knee replacements done in the English National Health Service). In hip patients, 3-y revision rates were 0.9% (95% confidence interval [CI] 0.8%–1.1%) with cemented, 2.0% (1.7%–2.3%) with cementless, 1.5% (1.1%–2.0% CI) with “hybrid” prostheses, and 2.6% (2.1%–3.1%) with hip resurfacing (p < 0.0001). Revision rates after hip resurfacing were increased especially in women. In knee patients, 3-y revision rates were 1.4% (1.2%–1.5% CI) with cemented, 1.5% (1.1%–2.1% CI) with cementless, and 2.8% (1.8%–4.5% CI) with unicondylar prostheses (p < 0.0001). Revision rates after knee replacement strongly decreased with age.
Interpretation
Overall, about one in 75 patients needed a revision of their prosthesis within 3 y. On the basis of our data, consideration should be given to using hip resurfacing only in male patients and unicondylar knee replacement only in elderly patients.
Jan van der Meulen and colleagues show that about one in 75 patients with a primary hip or knee replacement needed a revision of their prosthesis within 3 years.
Editors' Summary
Background.
Though records show attempts to replace a hip date back to 1891, it was not till the 1960s before total hip replacements were successfully performed, and the 1970s before total knee replacements were carried out. These procedures are some of the most frequently performed surgical operations, with a total of 160,00 total hip and knee replacement procedures carried out in England and Wales and about half a million in the US in 2006. Hip and knee replacements are most commonly used as a treatment for severe arthritis once other approaches, such as pain relief medications, have failed. A total hip replacement involves replacing the head of the femur (the thigh bone) with an artificial component, typically metal; the socket into which the new femur head will insert is also replaced with artificial components. In an alternative procedure, resurfacing, rather than replacing the entire joint, the diseased surfaces are replaced with metal components. This procedure may be better suited to patients with less severe disease, and is also thought to result in quicker recovery. The techniques for hip and knee replacement can also be divided into those where a cement is used to position the metal implant into the bone (cemented) versus those where cement is not used (cementless).
Why Was This Study Done?
To date, little evidence has been available to compare patient outcomes following hip or knee replacement with the many different types of techniques and prostheses available. National registries have been established in a number of countries to try to collect data in order to build the evidence base for evaluating different types of prosthesis. Specifically, it is important to find out if there are any important differences in revision rates (how often the hip replacement has to be re-done) following surgery using the different techniques. In England and Wales, the National Joint Registry (NJR) has collected data on patient characteristics, types of prostheses implanted, and the type of surgical procedures used, since its initiation in April 2003.
What Did the Researchers Do and Find?
The researchers linked the records of the NJR and the Hospital Episode Statistics (HES) for patients treated by the NHS in England who had undergone a primary hip and knee replacement between April 2003 and September 2006. The HES database contains records of all admissions to NHS hospitals in England, and allowed the researchers to more accurately identify revisions of procedures that were done on patients in the NJR database.
They identified 327,557 primary hip or knee replacement procedures performed during that time period, but only 167,076 could be linked between the two databases.
76,576 patients in the linked database had undergone a primary hip replacement. The overall revision rate was 1.4% (95% confidence interval [CI] 1.2%–1.5%) at 3 years, with the lowest revision rates experienced by patients who had cemented prostheses. Women were found to have higher revision rates after hip resurfacing, and the revision rate was about twice as high in patients who had had a hip replacement for other indications than osteoarthritis. A patient's age did not appear to affect revision rates after hip surgery.
80,697 patients in the linked database had undergone a primary knee replacement. The overall revision rate was 1.4% (95% CI 1.3%–1.6%) at three years, again with the lowest rates of replacement experienced by patients who had cemented prostheses. Revision rates after knee replacement strongly decreased with age.
What Do These Findings Mean?
Overall, about one in 75 patients required a revision of their joint replacement, which is considered low, and cemented hip or knee prosthesis had the lowest revision rates. Post hip replacement, the highest revision rate was in patients who had undergone hip resurfacing, especially women. Following knee replacement, the highest revision rate was in patients who had undergone unicondylar prosthesis. However, in this study patients were only followed up for three years after the initial knee replacement, and it's possible that different patterns regarding the success of these differing techniques may emerge after longer follow-up. Importantly, this study was entirely observational, and data were collected from patients who had been managed according to routine clinical practice (rather than being randomly assigned to different procedures). Substantial differences in the age and clinical characteristics of patients receiving the different procedures were seen. As a result, it's not possible to directly draw conclusions on the relative benefits or harms of the different procedures, but this study provides important benchmark data with which to evaluate future performance of different procedures and types of implant.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050179.
The website of the British Orthopaedic Association contains information for patients and surgeons
The website of the National Institute for Health and Clinical Excellence contains guidance on hip prostheses
Information is available from the US National Institutes of Health (Medline) on hip replacement, including interactive tutorials and information about rehabilitation and recovery
Medline also provides similar resources for knee replacement
The NHS provides information for patients on hip and knee replacement, including questions patients might ask, real stories, and useful links
The National Joint Registry provides general information about joint replacement, as well as allowing users to download statistics on the data it has collected on the numbers of procedures carried out in the UK
doi:10.1371/journal.pmed.0050179
PMCID: PMC2528048  PMID: 18767900
23.  Ipsilateral lower extremity joint involvement increases the risk of poor pain and function outcomes after hip or knee arthroplasty 
BMC Medicine  2013;11:144.
Background
Poor pain and function outcomes are undesirable after an elective surgery such as total hip or knee arthroplasty (THA/TKA). Recent studies have indicated that the presence of contralateral joint influences outcomes of THA/TKA, however the impact of ipsilateral knee/hip involvement on THA/TKA outcomes has not been explored. The objective of this study was to assess the association of ipsilateral knee/hip joint involvement on short-term and medium-term pain and function outcomes after THA/TKA.
Methods
In this retrospective study of prospectively collected data, we used the data from the Mayo Clinic Total Joint Registry to assess the association of ipsilateral knee or hip joint involvement with moderate to severe pain and moderate to severe activity limitation at 2-year and 5-year follow-up after primary and revision THA and TKA using multivariable-adjusted logistic regression analyses.
Results
At 2 years, 3,823 primary THA, 4,701 primary TKA, 1,218 revision THA and 725 revision TKA procedures were studied. After adjusting for multiple covariates, ipsilateral knee pain was significantly associated with outcomes after primary THA (all P values <0.01): (1) moderate to severe pain: at 2 years, odds ratio (OR), 2.3 (95% confidence interval (CI) 1.5 to 3.6); at 5 years, OR 1.8 (95% CI 1.1 to 2.7); (2) moderate to severe activity limitation: at 2 years, OR 3.1 (95% CI 2.3 to 4.3); at 5 years, OR 3.6 (95% CI 2.6 to 5.0). Ipsilateral hip pain was significantly associated with outcomes after primary TKA (all P values <0.01): (1) moderate to severe pain: at 2 years, OR 3.3 (95% CI 2.3 to 4.7); at 5 years, OR 1.8 (95% CI 1.1 to 2.7); (2) moderate to severe activity limitation: at 2 years, OR 3.6 (95% CI 2.6 to 4.9); at 5 years, OR 2.2 (95% CI 1.6 to 3.2). Similar associations were noted for revision THA and TKA patients.
Conclusions
To the best of our knowledge, this is the first study showing that the presence of ipsilateral joint involvement after THA or TKA is strongly associated with poor pain and function outcomes. A potential way to improve outcomes is to address ipsilateral lower extremity joint involvement.
doi:10.1186/1741-7015-11-144
PMCID: PMC3681648  PMID: 23738845
Arthroplasty; Ipsilateral; Joint replacement; Outcomes; Risk factors; Total hip replacement; Total knee replacement
24.  Revision Total Knee Arthroplasty with a Cemented Posterior Stabilized, Condylar Constrained or Fully Constrained Prosthesis: A Minimum 2-year Follow-up Analysis 
Clinics in Orthopedic Surgery  2010;2(2):112-120.
Background
The clinical and radiological outcomes of revision total knee arthroplasty with a cemented posterior stabilized (PS), condylar constrained knee (CCK) or a fully constrained rotating hinge knee (RHK) prosthesis were evaluated.
Methods
This study reviewed the clinical and radiological results of 36 revision total knee arthroplasties with a cemented PS, CCK, and RHK prosthesis in 8, 25, and 13 cases, respectively, performed between 1998 and 2006. The mean follow-up period was 30 months (range, 24 to 100 months). The reason for the revision was aseptic loosening of one or both components in 15, an infected total knee in 18 and a periprosthetic fracture in 3 knees. The average age of the patients at the time of the revision was 65 years (range, 58 to 83 years). The original diagnosis for all primary total knee arthroplasties was osteoarthritis except for one case of a Charcot joint. All revision prostheses were fixed with cement. The bone deficiencies were grafted with a cancellous allograft in the contained defect and cortical allograft fixed with a plate and screws in the noncontained defect. A medial gastrocnemius flap was needed to cover the wound dehiscence in 6 of the 18 infected cases.
Results
The mean Knee Society knee score improved from 28 (range, 5 to 43) to 83 (range, 55 to 94), (p < 0.001) and the mean Knee Society function score improved from 42 (range, 10 to 66) to 82 (range, 60 to 95), (p < 0.001) at the final follow-up. Good or excellent outcomes were obtained in 82% of knees. There were 5 complications (an extensor mechanism rupture in 3 and recurrence of infection in 2 cases). Three cases of an extensor mechanism defect (two ruptures of ligamentum patellae and one patellectomy) were managed by the RHK prosthesis to provide locking stability in the heel strike and push off phases, and two cases of recurrent infection used an antibiotic impregnated cement spacer. The radiological tibiofemoral alignment improved from 1.7° varus to 3.0° valgus in average. Radiolucent lines were observed in 18% of the knees without progressive osteolysis.
Conclusions
Revision total knee requires a more constrained prosthesis than primary total knee arthroplasty because of the ligamentous instability and bony defect. This short to midterm follow-up analysis demonstrated that a well planned and precisely executed revision can reduce pain and improve the knee function significantly. Infected cases showed as good a result as those with aseptic loosening through the use of antibiotics-impregnated cement beads and proper soft tissue coverage with a medial gastrocnemius flap.
doi:10.4055/cios.2010.2.2.112
PMCID: PMC2867196  PMID: 20514269
Total knee replacement; Revision; Prosthesis design; Treatment outcome
25.  Osteochondral Allografting for Knee Lesions in the Pediatric and Adolescent Population 
Orthopaedic Journal of Sports Medicine  2013;1(4 Suppl):2325967113S00076.
Objectives:
Osteochondral allografting is a useful reconstructive procedure for large ostechondral lesions of the knee. The purpose of this study was to evaluate the clinical outcome of osteochondral allografting in pediatric and adolescent patients.
Methods:
This IRB-approved study evaluated 39 patients (43 knees) less than 18 years of age who underwent osteochondral allografting between 1983 and 2010. The mean age was 16.4 years (range, 11.1 to 17.9) and 61% were male. The etiology of the lesions were osteochondritis dissecans in 26 knees (60.5%), avascular necrosis in 7 (16.3%), traumatic chondral injury in 6 (14%), degenerative chondral lesion in 2 (4.7%), and fracture in 2 (4.7%). Thirty-four patients (79%) underwent an average of 1.5 previous surgeries on the operative knee. Surgery was preformed using either a dowel or shell technique with fresh allograft tissue. The mean graft area was 8.4 cm2 (range, 2.2 to 20.8). The majority of grafts (76.7%) were located on the femoral condyle. Function and pain were assessed preoperatively and postoperatively using the International Knee Documentation Committee (IKDC) score, the Knee Society function (KS-F) score, and the modified Merle d’Aubigné-Postel (18-point) scale. Postoperative assessment included patient satisfaction, reoperations, and allograft survivorship. Failure was defined as any further procedure that resulted in removal of the allograft.
Results:
The mean follow-up was 8.4 years (range, 1.7-27.1). The IKDC score improved from 42 to 75 and the KS-F score improved from 69.3 to 89.4 (both p<0.05). Using the modified Merle d’Aubigné-Postel (18-point) scale, 87.5% of patients had a “good” or “excellent” score postoperatively, compared to 17% preoperatively. Patient satisfaction was 88.6%. Sixteen of 43 knees (37.2%) had reoperations following the allograft surgery. Kaplan-Meier survivorship was 92.9% at 5 years and 89.8% at 10 years. Five failures (11.6%) occurred, which were all salvaged with revision allografting.
Conclusion:
Osteochondral allografting was successfully employed to treat complex knee chondral and osteochondral pathology in patients less than 18 years of age. This procedure yielded improved function, decreased pain, and high satisfaction at an average follow-up of 8 years. Failure rates were relatively low, and when they did occur, were successfully revised with a second allograft procedure.
doi:10.1177/2325967113S00076
PMCID: PMC4589006

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