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1.  Level of Evidence Trends in the Journal of Bone and Joint Surgery, 1980-2010 
The Iowa Orthopaedic Journal  2014;34:197-203.
The Journal of Bone and Joint Surgery (JBJS-Am) began publishing the level of evidence (LOE) for manuscripts in 2003. From 1975 to 2005 JBJS-Am saw a trend towards higher leveled studies. We aimed to demonstrate trends in the country of origin of manuscripts published in JBJS-Am, and hypothesized that not only were more publications coming from groups outside of North America, but that the studies originating within North America were of higher LOE.
All articles published in The Journal of Bone and Joint Surgery (American) in 1980, 1985, 1990, 1995, 2000, 2005, and 2010 were independently evaluated by two reviewers and graded based on country, LOE (using the JBJS-Am LOE guidelines), and study type. For articles published after 2003 we used the level and study type published within the manuscript.
The proportion of publications from North America decreased in 2005 and 2010 when compared to the previous 20 years (p>.03), but the overall number of publications appeared stable. Overall, there was an increase in Level I (r>.74, p>.03), Level II (r>.79, p>.02), and Level III (r>.95, p<.001) evidence studies. There was a statistically significant decrease in North American Level IV studies (r>-.81, p>.01) and an increase in international Level IV studies (r>.70, p>.04). International groups have increased therapeutic (r>.86, p<.01) and diagnostic studies (r>.93, p<.001). In North America and internationally, prognostic studies have not changed. North American groups have increased economic and decision analysis research (r>.69, p>.04).
Over the past 30 years JBJS-Am has become more internationally diverse. International groups are publishing more therapeutic and diagnostic research than in the past, while North American groups have increased economic and decision analysis research. There has been a global effort towards higher leveled research.
PMCID: PMC4127720  PMID: 25328482
2.  Functional Outcomes of Mpfl Reconstruction VS. Graft Tissue Placement 
The medial patellofemoral ligament (MPFL) is essential for the maintenance of correct biomechanical function of the knee. Reconstruction of the MPFL is commonly used in the restoration of patellofemoral stability after traumatic lateral subluxation of the patella. Although a method to accurately determine the MPFL's insertion point has been described, it remains unclear if anatomic placement of MPFL graft tissue is essential for preservation of knee function after MPFL reconstruction. Thus, the purpose of this study was to determine the importance of anatomic placement of MPFL graft tissue for the preservation of knee function following MPFL reconstruction operations.
Twenty-seven subjects who underwent MPFL reconstruction operations were retrospectively analyzed. Postoperative radiographs were reviewed. Measurements were taken, and the placement of each patient's MPFL graft tissue was determined to be anatomic or non-anatomic based on radiographic methods previously described in the literature. Each subject's electronic medical record was then reviewed, and clinical data was recorded. Finally, the clinical outcomes of each patient were compared to placement location of the MPFL graft tissue in their procedure.
Thirteen patients were found to have anatomic MPFL graft tissue placement, and 14 non-anatomic. A significant post-operative difference was found between groups in the following parameters: WOMAC pain (anatomic mean = 85.71 ± 11.34, non-anatomic mean = 75.00 ± 26.35 p = 0.018), function (anatomic mean = 85.85 ± 9.96, non-anatomic mean = 79.09 ± 24.45, p = 0.017) and in KOOS symptom (anatomic mean = 75.63 ± 11.79, non-anatomic mean = 67.83 ± 22.40, p = 0.024), pain (anatomic mean = 77.54 ± 8.61, non-anatomic mean = 71.39 ± 25.18, p = 0.01), ADL (anatomic mean = 85.85 ± 9.97, non-anatomic mean = 79.09 ± 24.45, p = 0.017) and overall (anatomic mean = 74.61 ± 10.33, non-anatomic mean = 69.41 ± 24.25, p = 0.01) scores. No significant difference was observed for post-op instability (p = 0.290) or apprehension (p = 0.496), improvement in WOMAC or KOOS, 2-week, 6-week, or final 1-year range of motion, WOMAC stiffness, or KOOS sport/recreation or QOL.
Within the range of graft placement values considered by this study, while no reduction in range of motion was seen, non-anatomic placement of MPFL graft tissue in MPFL reconstruction operations caused increased pain and decreased function, evidenced by post-operative KOOS and WOMAC scores.
Clinical Relevance
It seems that the pivotal step in MPFL reconstruction operations is ensuring correct patellofemoral tracking via intraoperative electrical femoral nerve stimulation. If this step of the procedure is performed correctly, non-anatomic placement will not limit range of motion, lead to continued apprehension, or affect the overall biomechanical functioning of the knee.
PMCID: PMC4127708  PMID: 25328457
medial patellofemoral ligament (MPFL); patellar instability; lateral patellar subluxation; MFPL graft tissue placement; anatomy; radiographic landmarks; outcome scores; WOMAC; KOOS
3.  Impingement and Dislocation in Total HIP Arthroplasty: Mechanisms and Consequences 
In contemporary total hip arthroplasty, instability has been a complication in approximately 2% to 5% of primary surgeries and 5% to 10% of revisions. Due to the reduction in the incidence of wear-induced osteolysis that has been achieved over the last decade, instability now stands as the single most common reason for revision surgery. Moreover, even without frank dislocation, impingement and subluxation are implicated in a set of new concerns arising with advanced bearings, associated with the relatively unforgiving nature of many of those designs. Against that backdrop, the biomechanical factors responsible for impingement, subluxation, and dislocation remain under-investigated relative to their burden of morbidity.
This manuscript outlines a 15-year program of laboratory and clinical research undertaken to improve the scientific basis for understanding total hip impingement and dislocation. The broad theme has been to systematically evaluate the role of surgical factors, implant design factors, and patient factors in predisposing total hip constructs to impinge, sublux, and/or dislocate. Because this class of adverse biomechanical events had not lent itself well to study with existing approaches, it was necessary to develop (and validate) a series of new research methodologies, relying heavily on advanced finite element formulations. Specific areas of focus have included identifying the biomechanical challenges posed by dislocation-prone patient activities, quantifying design parameter effects and component surgical positioning effects for conventional metal-on-polyethylene implant constructs, and the impingement/dislocation behavior of non-conventional constructs, quantifying the stabilizing role of the hip capsule (and of surgical repairs of capsule defects), and systematically studying impingement and edge loading of hard-on-hard bearings, fracture of ceramic liners, confounding effects of patient obesity, and subluxation-mediated worsening of third body particle challenge.
PMCID: PMC4127709  PMID: 25328453
The Iowa Orthopaedic Journal  2014;34:181-189.
Orthopaedic surgical skill is traditionally acquired during training in an apprenticeship model that has been largely unchanged for nearly 100 years. However, increased pressure for operating room efficiency, a focus on patient safety, work hour restrictions, and a movement towards competency-based education are changing the traditional paradigm. Surgical simulation has the potential to help address these changes. This manuscript reviews the scientific background on skill acquisition and surgical simulation as it applies to orthopaedic surgery. It argues that simulation in orthopaedics lags behind other disciplines and focuses too little on simulator validation. The case is made that orthopaedic training is more efficient with simulators that facilitate deliberate practice throughout resident training and more research should be focused on simulator validation and the refinement of skill definition.
PMCID: PMC4127711  PMID: 25328480
5.  Minimizing Alteration of Posterior Tibial Slope During Opening Wedge High Tibial Osteotomy: a Protocol with Experimental Validation in Paired Cadaveric Knees 
The High Tibial Osteotomy (HTO) is a reliable procedure in addressing uni- compartmental arthritis with associated coronal deformities. With osteotomy of the proximal tibia, there is a risk of altering the tibial slope in the sagittal plane. Surgical techniques continue to evolve with trends towards procedure reproducibility and simplification. We evaluated a modification of the Arthrex iBalance technique in 18 paired cadaveric knees with the goals of maintaining sagittal slope, increasing procedure efficiency, and decreasing use of intraoperative fluoroscopy.
Nine paired cadaveric knees (18 legs) underwent iBalance medial opening wedge high tibial osteotomies. In each pair, the right knee underwent an HTO using the modified technique, while all left knees underwent the traditional technique. Independent observers evaluated postoperative factors including tibial slope, placement of hinge pin, and implant placement. Specimens were then dissected to evaluate for any gross muscle, nerve or vessel injury.
Changes to posterior tibial slope were similar using each technique. The change in slope in traditional iBalance technique was -0.3° ±2.3° and change in tibial slope using the modified iBalance technique was -0.4° ±2.3° (p=0.29). Furthermore, we detected no differences in posterior tibial slope between preoperative and postoperative specimens (p=0.74 traditional, p=0.75 modified).
No differences in implant placement were detected between traditional and modified techniques. (p=0.85). No intraoperative iatrogenic complications (i.e. lateral cortex fracture, blood vessel or nerve injury) were observed in either group after gross dissection.
Discussion & Conclusions
Alterations in posterior tibial slope are associated with HTOs. Both traditional and modified iBalance techniques appear reliable in coronal plane corrections without changing posterior tibial slope. The present modification of the Arthrex iBalance technique may increase the efficiency of the operation and decrease radiation exposure to patients without compromising implant placement or global knee alignment.
PMCID: PMC4127712  PMID: 25328454
6.  Biomechanical Performance of Variable and Fixed Angle Locked Volar Plates for the Dorsally Comminuted Distal Radius 
The Iowa Orthopaedic Journal  2014;34:123-128.
The ideal treatment strategy for the dorsally comminuted distal radius fracture continues to evolve. Newer plate designs allow for variable axis screw placement while maintaining the advantages of locked technology. The purpose of this study is to compare the biomechanical properties of one variable axis plate with two traditional locked constructs.
Simulated fractures were created via a distal 1 cm dorsal wedge osteotomy in radius bone analogs. The analogs were of low stiffness and rigidity to create a worst-case strength condition for the subject radius plates. This fracture-gap model was fixated using one of three different locked volar distal radius plates: a variable axis plate (Stryker VariAx) or fixed axis (DePuy DVR, Smith & Nephew Peri-Loc) designs. The constructs were then tested at physiologic loading levels in axial compression and bending (dorsal and volar) modes. Construct stiffness was assessed by fracture gap motion during the different loading conditions. As a within-study control, intact bone analogs were similarly tested.
All plated constructs were significantly less stiff than the intact control bone models in all loading modes (p<0.040). Amongst the plated constructs, the VariAx was stiffest axially (p=0.032) and the Peri-Loc was stiffest in bending (p<0.024).
In this analog bone fracture gap model, the variable axis locking technology was stiffer in axial compression than other plates, though less stiff in bending.
PMCID: PMC4127713  PMID: 25328471
7.  A Method to Modify Angle-Stable Intramedullary Nail Construct Compliance 
Traditional interlocked intramedullary (IM) nails have recently been modified to provide enhanced angular stability. These so-called ‘angle-stable’ IM nails are designed to eliminate construct toggle and also provide increased axial, bending, and torsional stiffness. While this added stability is needed for small fracture gaps to heal, angle-stable nails may be too stiff for large fracture gaps to unite. Even though relative stability is recommended for large fracture gaps, recent in vivo data indicates that traditional nails may allow for too much motion for healing to occur. The current study evaluated a modified technique for implanting an angle-stable nail which allows for an intermediate amount of stability. The compliance of the nail construct was adjusted by over-drilling the near cortex interlocking hole. This led to increased construct motion in torsion, but less so in axial compression and bending. This modification creates stability which is partway between angle-stable and traditional IM nail designs. These findings were unchanged after 50,000 fatigue loading cycles. By carefully selecting the magnitude of over-drilling, the compliance of the construct can easily be modified as it is being implanted. This design modification may lead to more reliable fracture union since the surgeon can tailor the nail compliance to the injury and bone quality.
PMCID: PMC4127714  PMID: 25328462
8.  Musculoskeletal Pain in Resident Orthopaedic Surgeons: Results of a Novel Survey 
The Iowa Orthopaedic Journal  2014;34:190-196.
The physical demands and high rates of musculoskeletal injury among practicing orthopaedic surgeons have been previously recognized in the literature. However, there is a paucity of data regarding musculoskeletal symptoms among resident orthopaedic surgeons. We sought to answer the following questions: (1) are there significant levels of musculoskeletal symptoms among resident orthopaedic surgeons?; (2) do residents attribute these symptoms to their work as surgeons?; and (3) is our survey instrument reliable enough for use in future investigations?
We developed an online, cross-sectional survey based on the previously validated Nordic Musculoskeletal Questionnaire and distributed it to 39 resident orthopaedic surgeons at our institution in 2011, with 82% responding. Fifteen participants repeated the survey to assess agreement and reliability between repeated administrations of the survey.
Significant levels of musculoskeletal symptoms were found in the resident surgeons, with the most common self-reported symptoms reported in the neck (59%), lower back (55%), upper back (35%), and shoulders (34%). Large proportions of these symptoms were self-reportedly attributed to the residents' work as a surgeon. Intrarater reliability revealed moderate to almost perfect agreement in nearly all repeated survey items.
Given that there are similar rates of musculoskeletal symptoms among our resident orthopedists and practicing orthopedists, more attention needs to be paid to the ergonomic and physical environments in which we are training the next generation of surgeons, especially when considering the extensive societal investment in training for these specialists.
PMCID: PMC4127715  PMID: 25328481
9.  Distinctive Damage Patterns on THA Metal Bearing Surfaces: Case Studies 
Retrieval analysis of total joint arthroplasty components has primarily focused on assessing wear or other damage to polyethylene components. As damage to the opposing bearing surface can accelerate polyethylene wear and damage, and especially with the use of hard-on-hard articulations, retrieval analysis benefits from incorporating evaluation of hard bearing surfaces as well. The purpose of this study is to report six case studies of metal bearing surfaces with distinctive damage patterns, to interpret them in the context of adverse events plausibly responsible for their creation, and to suggest their likely clinical or scientific significance. The specific damage patterns reported here are 1) extensive scraping, 2) circumferential discoloration, 3) a long chain of periodic micro-indentations, 4) pitting with deposits, 5) scratches with small-radius directional changes, and 6) indentation with scraping.
PMCID: PMC4127716  PMID: 25328465
10.  Methods for Locating the Tibio-Femoral Contact Pathway in Total Knee Replacements Using Marker-Based Gait Analysis and Standard Radiography 
The purpose of this study was to develop and test techniques for tracking the path of contact between the tibial and femoral total knee replacement components during level over-ground walking. The tibio-femoral path of contact could be an indicator of the in vivo performance of a total knee replacement as an estimator of areas of contact between the implant components. A longer contact path, indicative of more sliding between the implant components during walking, could indicate an implant at risk for increased wear. In addition, the tibio-femoral contact path determines the position and length of the muscle and ligament lever arms about the knee, and can subsequently influence knee contact force calculations.
Two methods were developed to predict the tibio-femoral contact pathways for total knee replacement devices. Both methods used patient-specific knee kinematics obtained during gait analysis, standard radiographs obtained during clinical follow-ups, and point-clouds of the tibial and femoral bearing surfaces. The validity of the techniques was evaluated with knee wear simulator tests and comparisons to wear scars on postmortem retrieved tibial components.
The average total anterior-posterior distance covered by the contact path for ten patients implanted with a total knee replacement was 29.01 mm on the lateral side, and 21.80 mm on the medial side. Both methods for predicting the tibiofemoral contact pathways yielded similar results, and fell within the wear scars of simulator-tested and postmortem retrieved implants.
The methods for predicting the tibio-femoral contact pathway using marker-based gait analysis and standard clinical radiographs are computationally simple, and reliably predict contact path characteristics as evaluated against wear scars from knee wear simulator tests and postmortem retrieved implants.
PMCID: PMC4127717  PMID: 25328466
tibio-femoral contact path; total knee replacement; marker-based gait analysis; knee contact mechanics
11.  Under-Utilization of the OTA Fracture Classification in the Orthopaedic Trauma Literature 
The OTA Fracture Classification is designed to provide a common language and facilitate effective communication among orthopaedic surgeons. We attempted to measure the degree to which this classification is currently being utilized in orthopaedic trauma literature.
We reviewed all of the articles in the JOT in 2011. We determined which of these articles could have appropriately utilized the 2007 OTA Classification. We calculated the percentage that mentioned and correctly cited this classification system as a reference.
There were 145 articles in 2011. One hundred of these articles were appropriate for classifying a fracture. 38% of these articles utilized the OTA classification in the text. Only 42% of articles mentioning the OTA Classification cited a reference. 38% of these citations used the old (1996) OTA Classification reference, and only 8% overall correctly cited the 2007 OTA Classification reference. 51% of articles mentioned some other classification system; 21 in addition to OTA and 30 instead of the OTA classification.
The OTA Fracture Classification is being used more commonly (38%) but is not routinely used or correctly cited (8%) in articles currently being published in the Journal of Orthopaedic Trauma, despite the fact that it is “required” according to the instructions to authors. We conclude that future authors should utilize and correctly reference the 2007 OTA Classification so that the benefits of a common language can be realized. Routine and consistent utilization of the classification may ultimately lead to more consistency and improved interpretability of treatment outcomes in published orthopaedic trauma research.
Level of Evidence
Level-III case-control study, decision analysis
PMCID: PMC4127719  PMID: 25328459
12.  Clinical Outcomes of Patellar Chondral Lesions Treated with Juvenile Particulated Cartilage Allografts 
Juvenile particulated cartilage allograft (DeNovo NT®, Zimmer, Warsaw, IN) transplantation is a relatively new technology for the treatment of high-grade cartilage lesions. To date there is limited literature demonstrating its effectiveness and safety. The present study specifically looks at the short-term efficacy of DeNovo NT® allograft for symptomatic high-grade cartilage lesions of the patella. Clinical outcomes and complications are reported.
Seventeen cases of DeNovo NT® allograft transplantation at our institution were retrospectively reviewed from 2010 to 2013. Thirteen patients had the procedure performed for patellar lesions and are included in the present study. A chart review was performed to record demographic data, surgical technique, and complications. In addition, we analyzed preoperative and postoperative KOOS outcome scores.
The mean age was 22.5 years (range, 14 - 34), with 3 males and 10 females. Mean follow-up was 8.2 months (range, 0.67 - 32.7). Six of the patients had concomitant anteromedialization of the tibial tubercle. DeNovo NT® allograft transplantation resulted in improvement for each outcome measure used. Overall KOOS score significantly improved from a mean of 58.4+15.7 to 69.2+18.6 (P = 0.04). Improvement in KOOS subscales of pain, ADL, and symptoms all approached but did not reach statistical significance (P values between 0.05 and 0.10). There were no infections or hardware complications.
This series demonstrates that DeNovo NT® allograft transplantation for symptomatic high-grade cartilage lesions of the patella results in pain relief and improved outcomes in the short term.
Further studies are needed to better evaluate this new technology.
Level of Evidence: Level IV, therapeutic case series
PMCID: PMC4127721  PMID: 25328458
13.  The Standard One Gram Dose of Vancomycin is not Adequate Prophylaxis for MRSA 
The Iowa Orthopaedic Journal  2014;34:111-117.
The indications for vancomycin prophylaxis to prevent Methicillin-resistant Staphylococcus aureus (MRSA) surgical site infections are increasing. The recommended dose of vancomycin has traditionally been 1 gram intravenous. However, the increasing prevalence of obesity in our population coupled with increasing resistance of MRSA to vancomycin has resulted in recent recommendations for weight-based dosing of vancomycin at 15mg/kg. We hypothesize that the standard one gram dose of vancomycin is inadequate to meet the recently recommended dosage of 15mg/kg.
We performed a retrospective chart review on 216 patients who were screened positive for MRSA prior to undergoing elective total joint or spine surgeries between January 2009 to January 2012. All patients were given 1 gram of vancomycin within an hour prior to surgical incision as prophylaxis. Using the revised dosing protocol of 15mg/kg of body weight for vancomycin, proper dosage was calculated for each patient. These values were then compared to the 1 gram dose given to the patients at time of surgery. Patients were assessed as either underdosed (a calculated weight-based dose >1 gram) or overdosed (a calculated weight-based dose <1 gram). Additionally, we used actual case times and pharmacokinetic equations to determine the vancomycin (VAN) levels at the end of the procedures.
Out of 216 patients who tested positive for MRSA, 149 patients (69%) were determined to be underdosed and 22 patients (10%) patients were determined to be overdosed. The predicted VAN level at the end of procedure was <15 mg/L in 60% of patients with 1 gram dose compared to 12% (p=0.0005) with weight base dose. Six patients developed post-operative MRSA surgical site infections (SSI). Of these six patients; four had strains of MRSA with vancomycin minimum inhibitory concentration of >1.0mg/L. Based on 1g dosing, 5/6 patients with MRSA positive SSIs had wound closure levels of <15 mg/L and all six were <20 mg/L.
In settings such as hospitals, where the risk for resistant bacteria, especially MRSA, is high, it is becoming increasingly important to accurately dose patients who require vancomycin. In order to avoid incorrect dosing of vancomycin health care providers must use weight-based dosing.
PMCID: PMC4127722  PMID: 25328469
MRSA; surgical site infections; vancomycin; weight based dosing; total joint surgery; spine surgery
14.  Transportation of Pediatric Femur Fractures to a Tertiary Care Center: a Retrospective Review 
The Iowa Orthopaedic Journal  2014;34:166-170.
Pediatric femur fractures are common injuries presenting to tertiary care trauma centers. Transportation of these patients occurs most commonly via ambulance or flight. The purpose of this study is to evaluate whether mode of transportation affects time to surgery or hospital stay for pediatric patients with femur fractures.
Utilizing a trauma registry we queried pediatric femur fractures between January 2001 and December 2009. Patient age, gender, mechanism of injury, month of injury, type of fracture, transportation, county of origin, time to operating room (TTOR), hospital length of stay (HLOS), and treatment received were identified and compared.
In total, 519 femur fractures were identified, 257 (49.5%) of which were isolated injuries. Flight transportation was utilized in 13.6 % (35 of 257) of these isolated fractures. Mean TTOR for flight patients was 29 hours, HLOS 3.2 days. For ambulance transportation mean TTOR was 41 hours, HLOS 3.2 days. Neither variable was statistically different between transportation groups (TTOR p > 0.50; HLOS p > 0.95). No statistical difference was seen in HLOS (p > 0.47) and TTOR (p > 0.71) for patients originating further distances from the hospital.
Transportation method and distance from the hospital did not affect the TTOR and HLOS for isolated pediatric femur fractures. The use of air transportation for this group of patients, many of whom are injured by relatively low energy mechanisms, may be excessively costly and does not accelerate treatment.
PMCID: PMC4127723  PMID: 25328477
15.  Distal Radial Fractures: the Significance of the Number of Instability Markers in Management and Outcome 
The Iowa Orthopaedic Journal  2014;34:118-122.
Distal radial fractures are one of the most common orthopaedic injuries. An effective treatment strategy is needed to ensure good outcome and better resource usage.
To identify the significance of the number of instability markers in distal radial fractures in predicting outcome and proposing a standardized management strategy.
Data was collected retrospectively over three months at the Northern General Hospital, Sheffield. All patients who had a distal radius fracture in the defined time period and matched our criteria were included. Relevant instability markers identified through a literature review were: age >60 years, dorsal angulation >20°, intra-articular fracture, ulna fracture, dorsal comminution, radial shortening and osteoporosis. The number of instability markers, management and outcome were recorded for each patient. The strategy of management was subdivided into: plaster cast immobilisation with subsequent rehabilitation, manipulation with subsequent cast immobilization and surgery (locked volar plating). Outcomes were graded as “good” or “poor” based on the complications and the function achieved at discharge from follow-up.
Two hundred and seven patients were included in our study. One hundred and nineteen patients had <3 instability markers (Group A) and 88 had >4 (Group B). One hundred and sixty-two were female and 45 were male. The average age was 60 years and the age range was 19 to 96 years. In Group A, 91% achieved “good” outcome regardless of management strategy, versus 66% in Group B (p<0.001). In Group B, amongst patients who had surgery (29), 79% achieved “good” outcome, however those with manipulation alone (38), only 58% achieved “good” outcome (p > 0.03 (one tailed), p > 0.06 (double tailed)).
We have found that four or more instability markers are globally associated with a poorer outcome. Patients with four or more markers who underwent surgery did uniformly better than those with manipulation alone. However, in patients with three or fewer markers, non-operative management yielded equally good outcomes. We plan to use this as a pilot study for future primary research.
PMCID: PMC4127724  PMID: 25328470
instability; markers; distal; radial fractures
16.  Patella Fracture Fixation with Suture and Wire: you Reap what you Sew 
Operative fixation of displaced inferior pole patella fractures has now become the standard of care. This study aims to quantify clinical, radiographic and functional outcomes, as well as identify complications in a cohort of patients treated with non-absorbable braided suture fixation for inferior pole patellar fractures. These patients were then compared to a control group of patients treated for mid-pole fractures with K-wires or cannulated screws with tension band wiring.
In this IRB approved study, we identified a cohort of patients who were diagnosed and treated surgically for a displaced patella fracture. Demographic, injury, and surgical information were recorded. All patients were treated with a standard surgical technique utilizing non-absorbable braided suture woven through the patellar tendon and placed through drill holes to achieve reduction and fracture fixation. All patients were treated with a similar post-operative protocol and followed up at standard intervals. Data were collected concurrently at follow up visits.
For purpose of comparison, we identified a control cohort with middle third patella fractures treated with either k-wires or cannulated screws and tension band technique. Patients were followed by the treating surgeon at regular follow-up intervals. Outcomes included self-reported function and knee range of motion compared to the uninjured side.
Forty-nine patients with 49 patella fractures identified retrospectively were treated over 9 years. This cohort consisted of 31 females (63.3%) and 18 males (36.7%) with an average age of 57.1 years (range 26 - 88 years). Patients had an average BMI of 26.48 (range 19 - 44.08).
Thirteen patients with inferior pole fractures underwent suture fixation and 36 patients with mid-pole fractures underwent tension band fixation (K-wire or cannulated screws with tension band). In the suture cohort, one fracture failed open repair (7.6%), which was revised again with sutures and progressed to union. Of the 36 fractures repaired with a tension band fixation, 11 underwent secondary surgery due to hardware pain or fixation failure (30.6%).
At one year, no difference was seen in knee range of motion between cohorts. All fractures healed radiographically. Those patients who required reoperation or removal of hardware had significantly diminished range of motion about their injured knee (p > 0.005).
Patients who sustain inferior pole patella fractures have limited options for fracture fixation. Suture repair is clinically acceptable, yielding similar results to patella fractures repaired with metal implants. Importantly, patients undergoing suture repair appear to have fewer hardware related postoperative complications than those receiving wire fixation for midpole fractures.
PMCID: PMC4127725  PMID: 25328461
Patella fracture; suture fixation; wire fixation
17.  Magnetic Resonance Imaging of Diabetic Muscle Infarction: Report of Two Cases 
Diabetic muscle infarction (DMI) occurs as a rare complication of long standing or severe diabetes mellitus. The condition usually occurs spontaneously and patients usually present with acute pain and swelling of affected muscles which persists for weeks, and resolves spontaneously without intervention. Magnetic resonance (MR) imaging is the modality of choice in patients with suspected DMI based on appropriate clinical setting and plays a major role in the diagnosis, assessing the extent of involvement and differentiating DMI from other conditions. The DMI affected muscles are bulky and appear heterogeneous with hyperintense signals on T2-weighted and STIR sequences, hypo or isointense on T1-weighted images with loss of normal fatty intramuscular septae. Subcutaneous and perifascial edema can be present. On postgadolinium scans, there is diffuse heterogeneous enhancement with non-enhancing foci, which may represent areas of necrosis. Biopsy can be avoided as MR findings are highly sensitive and specific. Treatment is usually conservative. Surgical intervention is required only in patients who do not respond to conservative management. The common differential diagnosis includes cellulitis, abscess, necrotizing fasciitis and polymyositis. We present two cases below to highlight the clinical, MR imaging findings and differential diagnosis of DMI.
PMCID: PMC4127726  PMID: 25328463
18.  Sheep Cervical Spine Biomechanics: a Finite Element Study 
The Iowa Orthopaedic Journal  2014;34:137-143.
Animal models are often used to make the transition from scientific concepts to clinical applications. The sheep model has emerged as an important model in spine biomechanics. Although there are several experimental biomechanical studies of the sheep cervical spine, only a limited number of computational models have been developed. Therefore, the objective of this study was to develop and validate a C2-C7 sheep cervical spine finite element (FE) model to study the biomechanics of the normal sheep cervical spine.
The model was based on anatomy defined using medical images and included nonlinear material properties to capture the high flexibility and large neutral zone of the sheep cervical spine. The model was validated using comprehensive experimental flexibility testing. Ten adult sheep cervical spines, from C2-C7, were used to experimentally ascertain overall and segmental flexibility to ±2 Nm in flexion-extension, lateral bending, and axial rotation.
The ranges of motion predicted by the computational model were within one standard deviation of the respective experimental motions throughout the load cycle, with the exception of extension and lateral bending. The model over- and under predicted the peak motions in extension and lateral bending, respectively. Nevertheless, the model closely represents the range of motion and flexibility of the sheep cervical spine.
This is the first multilevel model of the sheep cervical spine. The validated model affords additional biomechanical insight into the intact sheep cervical spine that cannot be easily determined experimentally. The model can be used to study various surgical techniques, instrumentation, and device placement, providing researchers and clinicians insight that is difficult, if not impossible, to gain experimentally.
PMCID: PMC4127727  PMID: 25328473
19.  Osteochondral Allograft of the Talus 
Osteochondral lesions of the talus are being recognized as an increasingly common injury. They are most commonly located postero-medially or antero-laterally, while centrally located lesions are uncommon. Large osteochondral lesions have significant biomechanical consequences and often require resurfacing with osteochondral autograft transfer, mosaicplasty, autologous chondrocyte implantation (or similar methods) or osteochondral allograft transplantation. Allograft procedures have become popular due to inherent advantages over other resurfacing techniques. Cartilage viability is one of the most important factors for successful clinical outcomes after transplantation of osteochondral allografts and is related to storage length and intra-operative factors. While there is abundant literature about osteochondral allograft transplantation in the knee, there are few papers about this procedure in the talus. Failure of non-operative management, initial debridement, curettage or microfractures are an indication for resurfacing. Patients should have a functional ankle motion, closed growth plates, absence of cartilage lesions on the tibial side. This paper reviews the published literature about osteochondral allograft transplantation of the talus focusing on indications, pre-operative planning, surgical approaches, postoperative management, results and complications of this procedure.
PMCID: PMC4127728  PMID: 25328456
20.  Patient Perceptions and Preferences when Choosing an Orthopaedic Surgeon 
The Iowa Orthopaedic Journal  2014;34:204-208.
Information regarding patient preferences is important to develop more diversity in healthcare providers. To our knowledge, no information exists regarding how patients choose their orthopaedic surgeon. The purpose of this study is to determine which demographic factors, if any, affect patient preferences when choosing an orthopaedic surgeon.
Five hundred new patients presenting to a large, urban, academic orthopaedic clinic from May 2011 to May 2013 were prospectively asked to participate in this study. Patients were asked to complete a survey designed with the help of the Division of Population Health that focused on demographic, professional and physical attributes of theoretical surgeons. Specifically, patient preference of surgeon age, gender, race, religion, importance of education prestige, training program prestige and number of medical publications were evaluated. Patients were then stratified by age, gender, race, religion, educational level and income level to assess whether their own demographics were related to their preferences. The data was then analyzed to determine whether correlations existed between patient preferences and their own demographics.
Five hundred patients agreed to participate in the study. There were 195 (39.0%) males and 281 (56.2%) females with an average age of 40.8 years (SD=20.5), 24 patients (4.8%) did not respond to the question. Two hundred and twelve (42.4%) patients were Caucasian, 116 (23.2%) were Hispanic, 53 (10.6%) were African American, 44 (8.8%) were Asian, 32 (6.4%) were listed as other and 43 (8.6%) did not answer. 78.0% of patients had no preference for their surgeon's gender, but for those who did, both men and woman preferred male surgeons (weak positive correlation, not statistically significant, r=0.096, p=0.373). The majority of patients (84.8%) had no preference for the race of their surgeon, but those that had a preference tended to prefer surgeons of their own ethnicity (p<0.001). With increasing patient education level, medical school, residency and fellowship training prestige had more importance as a selection criterion. Increasing patient education level also demonstrated a corresponding importance given to physician education and training as categorized by the perception of residency training program prestige (p=0.04). A majority of patients (84.0%) had no preference for their surgeon's religion, but for those who did there was a strong correlation (r=0.65), between the patients' own religion and that of the physician (p<0.001). There was universal agreement in perception that neither physician age nor years in practice made any difference as selection criteria when choosing an orthopaedic surgeon (p>0.05). Finally patient income level had no effect on specific criteria when choosing a surgeon.
The vast majority of patients surveyed had no preference in age, gender, race, or religion of their potential surgeon. However, patients who had preferences in these categories tended to choose surgeons of the same age, race and religion. These findings neither support or refute the need for diverse health care providers in the field of orthopaedics.
PMCID: PMC4127729  PMID: 25328483
orthopaedic surgeon; preference; diversity; perception
21.  Surgical Treatment of Spinal Tuberculosis Complicated with Extensive ABSCESS 
The Iowa Orthopaedic Journal  2014;34:129-136.
Tuberculosis can be responsible for extensive spinal lesions. Despite the efficacy of medical treatment, surgery is indicated to avoid or correct significant deformity, treat spinal instability, prevent neurological compromise, and to eradicate an extensive tuberculous abscess. In this paper we present our experience in the surgical management of spinal tuberculosis complicated with large abscess.
Patients and Methods
Fifteen patients with spinal tuberculosis complicated with extensive abscess were identified; and nine of those patients had extension of the infection into the epidural space. The average age at treatment was 34 years old. Seven patients had thoracic infection, seven patients had lumbar infection and one had thoracolumbar infection. Six patients had neurological deficit at presentation. All patients were surgically treated with abscess debridement, spinal stabilization and concurrent antituberculous chemotherapy. A single anterior surgical approach was used in three cases, a posterior approach was used in four others and a combined approach was performed in eight patients.
Surgical management allowed for effective abscess debridement and sspinal stabilization in this cohort. In combination with antituberculous drugs, surgical treatment resulted in infection eradication and bone fusion in all patients at 24 month average follow-up. Satisfactory neurological outcomes with improved American Spinal Injury Association (ASIA) scores were observed in 100% of patients.
Surgical treatment for spinal tuberculosis abscess can lead to satisfactory clinical outcomes.
PMCID: PMC4127730  PMID: 25328472
22.  A Case Report of Bilateral Mirror Clubfeet and Bilateral Hand Polydactyly 
The Iowa Orthopaedic Journal  2014;34:171-174.
We report a rare case of a patient with bilateral mirror clubfeet and bilateral hand polydactyly. The patient presented to our orthopaedic clinic with bilateral mirror clubfeet, each with eight toes, and bilateral hands with six fingers and a hypoplastic thumb. The pattern does not fit any described syndrome such as Martin or Laurin-Sandrow syndrome. Treatments by an orthopaedic pediatric surgeon and an orthopaedic pediatric hand surgeon are described. The patient achieved excellent functional and cosmetic outcomes at four year follow-up.
PMCID: PMC4127732  PMID: 25328478
23.  A Pediatric Comminuted Talar Fracture Treated by Minimal K-Wire Fixation Without Using a Tourniquet 
The Iowa Orthopaedic Journal  2014;34:175-180.
Pediatric comminuted talar fractures are reported to be rare, and treatment options such as minimal internal K-wire fixation without using a tourniquet to prevent avascular necrosis have not previously been investigated.
Case Description
We report a case of a comminuted talar body and a non-displaced neck fracture with dislocation of the tibiotalar, talonavicular and subtalar joints with bimalleolar epiphyseal fractures in an 11-year-old boy due to a fall from height. We present radiological findings, the surgical procedure and clinical outcomes of minimal internal K-wire fixation without using a tourniquet.
Literature Review
Avascular necrosis rates are reported to be between 0 % and 66 % after fractures of the neck of the talus and the talar body in children. The likelihood of developing avascular necrosis increases with the severity of the fracture.
Clinical Relevance
To avoid avascular necrosis in a comminuted talar fracture accompanied by tibiotalar, talonavicular, subtalar dislocations and bimalleolar epiphyseal fractures, a minimal internal K-wire fixation without the use of a tourniquet was performed. The outcome was evaluated by the American Orthopedic Foot and Ankle Society score (AOFAS). A score of 90 (excellent) was found at the end of the second year of follow up. Radiology revealed preservation of the joint with no evidence of avascular necrosis, and clinical findings revealed a favorable functional outcome after two years.
Level of Evidence
PMCID: PMC4127733  PMID: 25328479
talus; fracture healing; tourniquets; avascular; necrosis
24.  Progressive Adult Spinal Deformity Following Placement of Intrathecal Opioid Pump: a Report of Four Cases 
The Iowa Orthopaedic Journal  2014;34:144-149.
Placement of intrathecal opioid pumps (ITOP) for chronic pain is a rare, but described cause of progressive spinal deformity. Over the last two decades there has been several suspected cases at our institution. In this case series, we described the apparent association between placement of an intrathecal opioid pump and progression of spinal deformity.
The medical records of a single surgeon working at a single institution were retrospectively queried for patients seen between 1995-2010 to identify patients with spinal deformity and an ITOP. All hospital records including notes, radiographs, and labs were reviewed and analyzed. Spine radiographs were measured using standard techniques and reported as Cobb angles. This project was IRB approved and no external funding was used.
In total, we identified four patients with spinal deformity after placement of an ITOP. These patients were adults, two males and two females (ages: 48-80 years), with a unique medical history. Each participant's radiographs showed a progression of the spinal deformity following placement of ITOP. All patients underwent subsequent posterior spinal fusion for treatment of their progressive spinal deformities.
In this series, we have shown an apparent association between the placement of ITOP and progression of deformity in both patients with and without existing spinal deformity. While it is impossible to discern causality, all patients in our series had radiographic and clinical evidence of spinal deformity progression after placement of intrathecal pumps. These findings may raise awareness of this rare, but major, complication. In those performing pump placement, we recommend continued clinical and radiographic monitoring, through routine follow-up.
Level of Evidence
Level 4 - Case series; case control study (diagnostic studies); poor reference standard; analyses with no sensitivity analyses.
PMCID: PMC4127735  PMID: 25328474
25.  The Effect of Multi-Level Laminoplasty and Laminectomy on the Biomechanics of the Cervical Spine: a Finite Element Study 
The Iowa Orthopaedic Journal  2014;34:150-157.
Laminectomy has been regarded as a standard treatment for multi-level cervical stenosis. Concern for complications such as kyphosis has limited the indication of multi-level laminectomy; hence it is often augmented with an instrumented fusion. Laminoplasty has emerged as a motion preserving alternative. The purpose of this study was to compare the multidirectional flexibility of the cervical spine in response to a plate-only open door laminoplasty, double door laminoplasty, and laminectomy using a computational model. A validated three-dimensional finite element model of a specimen-specific intact cervical spine (C2-T1) was modified to simulate each surgical procedure at levels C3-C6. An additional goal of this work was to compare the instrumented computational model to our multi-specimen experimental findings to ensure similar trends in response to the surgical procedures. Model predictions indicate that mobility was retained following open and double door laminoplasty with a 5.4% and 20% increase in flexion, respectively, compared to the intact state. Laminectomy resulted in 57% increase in flexion as compared to the intact state, creating a concern for eventual kyphosis - a known risk/complication of multi-level laminectomy in the absence of fusion. Increased disc stresses were observed at the altered and adjacent segments post-laminectomy in flexion.
PMCID: PMC4127738  PMID: 25328475
cervical spine; laminectomy; laminoplasty; miniplates; spacer; finite element

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