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1.  Implant sonication for the diagnosis of prosthetic elbow infection 
Periprosthetic infection is a potentially devastating complication of elbow arthroplasty, associated with formation of microbial biofilm on the implant surface. The definitive microbiologic diagnosis of periprosthetic infection after elbow arthroplasty may be difficult to establish. Our study aim was to compare the diagnostic accuracy of conventional periprosthetic tissue culture and culture of fluid derived from vortexing and bath sonication of the explanted hardware (a biofilm-sampling strategy).
Materials and methods
Patients undergoing revision elbow arthroplasty at our institution between July 2007 and July 2010, from each of whom 2 or more periprosthetic tissue cultures and 1 implant sonicate culture were obtained, were studied. A standardized definition of orthopedic implant—associated infection was applied.
We identified 27 subjects with aseptic failure and 9 with prosthetic elbow infection. Rheumatoid arthritis was the most common underlying disorder. The Coonrad-Morrey prosthesis was the most common type of implant used. The sensitivities of implant sonicate and periprosthetic tissue culture were 89% and 55%, respectively (P = .18), and the specificities were 100% and 93%, respectively (P = .16). Coagulase-negative staphylococci (n = 7) and Staphylococcus aureus (n = 2) were isolated in cases of infection.
Culture of the implant by sonication is at least as sensitive as periprosthetic tissue culture to detect prosthetic elbow infection.
Level of evidence
Level I, Diagnostic Study.
PMCID: PMC3910532  PMID: 22078323
Prosthetic joint infection; elbow prosthesis; implant; sonication; biofilm; periprosthetic tissue
2.  Proximal Humerus Fractures in the Elderly Can Be Reliably Fixed With a “Hybrid” Locked-plating Technique 
Controversy exists regarding the best treatment of proximal humerus fractures in the elderly. Recent studies of open reduction and internal fixation have demonstrated high complication rates.
We asked whether (1) open reduction and internal fixation could be performed with low rates of immediate and delayed complications, (2) reduction of these fractures could be maintained over time by evaluating long-term radiographs and visual analog pain scores, and (3) 6-week immobilization would lead to disabling stiffness by evaluating postoperative motion and functional scores.
Patients and Methods
We retrospectively reviewed all 35 patients older than 75 years with displaced proximal humerus fractures treated using a “hybrid” technique between 2002 and 2008. All patients were immobilized for 6 weeks after surgery. Thirteen of the 35 patients either died or developed severe dementia during followup. The analysis included 22 patients followed a minimum of 1 year (mean, 3 years; range, 1–6.7 years).
There were no early or late reoperations in this series. An acceptable reduction was achieved in 89% of the shoulders and maintained over time. All fractures healed. Osteonecrosis was noted on radiographs in 11% of the shoulders. Six weeks of immobilization did not lead to disabling stiffness. At most recent followup, mean active elevation was 141°, mean active internal rotation L1, mean active external rotation 36°, and mean American Society of Shoulder and Elbow Surgeons score 68.
Utilizing this approach, open reduction and internal fixation followed by 6-week immobilization results in a low rate of reoperation and good functional outcomes for elderly patients with proximal humerus fractures.
Level of Evidence
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
PMCID: PMC3210261  PMID: 21479762
3.  Total Elbow Arthroplasty 
Total elbow arthroplasty has continued to evolve over time. Elbow implants may be linked or unlinked. Unlinked implants are attractive for patients with relatively well preserved bone stock and ligaments, but many favor linked implants, since they prevent instability and allow replacement for a wider spectrum of indications. Inflammatory arthropathies such as rheumatoid arthritis represent the classic indication for elbow arthroplasty. Indications have been expanded to include posttraumatic osteoarthritis, acute distal humerus fractures, distal humerus nonunions and reconstruction after tumor resection. Elbow arthroplasty is very successful in terms of pain relief, motion and function. However, its complication rate remains higher than arthroplasty of other joints. The overall success rate is best for patients with inflammatory arthritis and elderly patients with acute distal humerus fractures, worse for patients with posttraumatic osteoarthritis. The most common complications of elbow arthroplasty include infection, loosening, wear, triceps weakness and ulnar neuropathy. When revision surgery becomes necessary, bone augmentation techniques provide a reasonable outcome.
PMCID: PMC3093740  PMID: 21584200
Arthroplasty; elbow; rheumatoid arthritis; elbow fractures; osteoarthritis.
4.  Total Shoulder Arthroplasty 
Shoulder arthroplasty has been the subject of marked advances over the last few years. Modern implants provide a wide range of options, including resurfacing of the humeral head, anatomic hemiarthroplasty, total shoulder arthroplasty, reverse shoulder arthroplasty and trauma-specific implants for fractures and nonunions. Most humeral components achieve successful long-term fixation without bone cement. Cemented all-polyethylene glenoid components remain the standard for anatomic total shoulder arthroplasty. The results of shoulder arthroplasty vary depending on the underlying diagnosis, the condition of the soft-tissues, and the type of reconstruction. Total shoulder arthroplasty seems to provide the best outcome for patients with osteoarthritis and inflammatory arthropathy. The outcome of hemiarthroplasty for proximal humerus fractures is somewhat unpredictable, though it seems to have improved with the use of fracture-specific designs, more attention to tuberosity repair, and the selective use of reverse arthroplasty, as well as a shift in indications towards internal fixation. Reverse shoulder arthroplasty has become extremely popular for patients with cuff-tear arthropathy, and its indications have been expanded to the field of revision surgery. Overall, shoulder arthroplasty is a very successful procedure with predictable pain relief and substantial improvements in motion and function.
PMCID: PMC3093753  PMID: 21584206
Arthroplasty; shoulder; osteoarthritis; shoulder fractures; cuff-tear arthropathy; reverse arthroplasty.
5.  C-Reactive Protein, Erythrocyte Sedimentation Rate and Orthopedic Implant Infection 
PLoS ONE  2010;5(2):e9358.
C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) have been shown to be useful for diagnosis of prosthetic hip and knee infection. Little information is available on CRP and ESR in patients undergoing revision or resection of shoulder arthroplasties or spine implants.
We analyzed preoperative CRP and ESR in 636 subjects who underwent knee (n = 297), hip (n = 221) or shoulder (n = 64) arthroplasty, or spine implant (n = 54) removal. A standardized definition of orthopedic implant-associated infection was applied. Receiver operating curve analysis was used to determine ideal cutoff values for differentiating infected from non-infected cases. ESR was significantly different in subjects with aseptic failure infection of knee (median 11 and 53.5 mm/h, respectively, p = <0.0001) and hip (median 11 and 30 mm/h, respectively, p = <0.0001) arthroplasties and spine implants (median 10 and 48.5 mm/h, respectively, p = 0.0033), but not shoulder arthroplasties (median 10 and 9 mm/h, respectively, p = 0.9883). Optimized ESR cutoffs for knee, hip and shoulder arthroplasties and spine implants were 19, 13, 26, and 45 mm/h, respectively. Using these cutoffs, sensitivity and specificity to detect infection were 89 and 74% for knee, 82 and 60% for hip, and 32 and 93% for shoulder arthroplasties, and 57 and 90% for spine implants. CRP was significantly different in subjects with aseptic failure and infection of knee (median 4 and 51 mg/l, respectively, p<0.0001), hip (median 3 and 18 mg/l, respectively, p<0.0001), and shoulder (median 3 and 10 mg/l, respectively, p = 0.01) arthroplasties, and spine implants (median 3 and 20 mg/l, respectively, p = 0.0011). Optimized CRP cutoffs for knee, hip, and shoulder arthroplasties, and spine implants were 14.5, 10.3, 7, and 4.6 mg/l, respectively. Using these cutoffs, sensitivity and specificity to detect infection were 79 and 88% for knee, 74 and 79% for hip, and 63 and 73% for shoulder arthroplasties, and 79 and 68% for spine implants.
CRP and ESR have poor sensitivity for the diagnosis of shoulder implant infection. A CRP of 4.6 mg/l had a sensitivity of 79 and a specificity of 68% to detect infection of spine implants.
PMCID: PMC2825262  PMID: 20179760
6.  Midterm to Long-term Followup of Staged Reimplantation for Infected Hip Arthroplasty 
Most reports on two-stage reimplantation have focused on the short-term cure rate of infection, but little is known about long-term reinfection-free survival or mechanical durability. We retrospectively reviewed 168 patients (169 hips) with infected arthroplasty, all of whom had two-stage reimplantation for the treatment of an infected total hip arthroplasty between 1988 and 1998. In the second stage, the femoral component was fixed with antibiotic-loaded bone cement in 121 hips; the remaining femoral components and all acetabular components were uncemented. The minimum followup time was 2 years (mean, 7 years; range, 2–16 years). At most recent followup, 12 hips (7.1%) were reoperated on for reinfection and 13 hips (7.7%) were revised for aseptic loosening or osteolysis. Apparently aseptic loosening occurred on one or both sides of the joint in 24 hips (14.2%). The 10-year survivals free of reinfection and mechanical failure were 87.5% and 75.2% respectively. Nineteen hips dislocated and eight underwent revision surgery for instability. The method of femoral component fixation, either with or without cement, did not correlate with risk of infection, loosening, or mechanical failure. Based on these results, the method of fixation used for the femoral component during two-stage reimplantation surgery should be based on the surgeon’s preference for fixation combined with the assessment of femoral bone stock.
Level of Evidence: Level IV, case series. See the Guidelines for Authors for a complete description of levels of evidence.
PMCID: PMC2600996  PMID: 18813895
7.  Microbiologic Diagnosis of Prosthetic Shoulder Infection by Use of Implant Sonication▿  
Journal of Clinical Microbiology  2009;47(6):1878-1884.
We recently described a sonication technique for the diagnosis of prosthetic knee and hip infections. We compared periprosthetic tissue culture to implant sonication followed by sonicate fluid culture for the diagnosis of prosthetic shoulder infection. One hundred thirty-six patients undergoing arthroplasty revision or resection were studied; 33 had definite prosthetic shoulder infections and 2 had probable prosthetic shoulder infections. Sonicate fluid culture was more sensitive than periprosthetic tissue culture for the detection of definite prosthetic shoulder infection (66.7 and 54.5%, respectively; P = 0.046). The specificities were similar (98.0% and 95.1%, respectively; P = 0.26). Propionibacterium acnes was the commonest species detected among culture-positive definite prosthetic shoulder infection cases by periprosthetic tissue culture (38.9%) and sonicate fluid culture (40.9%). All subjects from whom P. acnes was isolated from sonicate fluid were male. We conclude that sonicate fluid culture is useful for the diagnosis of prosthetic shoulder infection.
PMCID: PMC2691098  PMID: 19261785
8.  Augmented repair of acute Achilles tendon ruptures using gastrocnemius-soleus fascia 
International Orthopaedics  2004;29(1):42-46.
Fifty-four consecutive acute Achilles tendon ruptures were treated with end-to-end suture augmented with gastrocnemius fascial flaps. Surgery was performed within 24 h. Mean patient age was 35 (23–57) years, and 46 were men. Mean follow-up time was 4.8 (2–8) years. At follow-up, the mean visual analogue scale for pain was 0.49, and the mean AOFAS ankle–hindfoot score was 95 (74–100) points. Fifty-three patients were able to stand on their tiptoes for 30 s and perform repeated toe raises, and 50 patients were able to perform single-limb hopping. Complications included rerupture in one case, deep infection in three cases, delayed wound healing in eight cases, and deep venous thrombosis in one case. Reconstruction of acute ruptures of the Achilles tendon augmented with gastrocnemius-soleus fascial flaps provided a good outcome but was associated with a high complication rate.
PMCID: PMC3456949  PMID: 15526200
9.  Comparison of wear and osteolysis in hip replacement using two different coatings of the femoral stem 
International Orthopaedics  2004;28(4):206-210.
We compared the clinical and radiographic results of two matched series of total hip arthroplasties, one with hydroxyapatite-coated femoral stems, the other with a similar but porous-coated femoral stem. The prevalence of radiographic osteolysis was 16% in hips with hydroxyapatite-coated stems and 43% in hips with porous-coated femoral stems. In hips with hydroxyapatite-coated stems, osteolysis was always limited to Gruen zones 1 and 7. In contrast, distal osteolysis was present around 26% of the porous-coated stems. At 7 years, the survival-free rate of distal osteolysis was 100% in hips with hydroxyapatite-coated stems but 90% in hips with porous-coated stems (p=0.04). Circumferential hydroxyapatite coating of the femoral component reduced the occurrence of osteolysis and eliminated distal osteolysis at 5–10 years of follow-up. In addition, hydroxyapatite coating did not alter the wear rate.
PMCID: PMC3456935  PMID: 15118841

Results 1-9 (9)