Arthrodesis for failed total elbow arthroplasty with deep infection.

BACKGROUND: Elbow arthrodesis is typically reserved as a salvage procedure. Current literature suggests that satisfactory outcomes can be expected if fusion occurs. There is a paucity of literature on outcomes of elbow arthrodesis after failed elbow arthroplasty with deep infection. METHODS: Five elbow arthrodeses were performed after a failed elbow arthroplasty due to deep infection. Clinical data were retrospectively reviewed for all surviving patients. Fusion angle, complications, and time to fusion or resection arthroplasty were recorded. The procedure was considered a failure if resection arthroplasty was required or there was a failure of bone union after 1 year. RESULTS: The average age at arthrodesis was 49 years (range, 35-69 years). One patient died 3 months after arthrodesis and was excluded from analysis. No patients had confirmed union at final follow-up. Two developed a fibrous union and were not symptomatic. All patients required at least 1 reoperation; 6 reoperations were required in total for the entire group. Three patients required revision arthrodesis after hardware failure. Two patients ultimately underwent a resection arthroplasty. One patient required débridement and hardware removal after wound dehiscence. Other complications included 2 patients with transient ulnar neuritis. CONCLUSION: Elbow arthrodesis is not recommended as a salvage procedure for failed total elbow arthroplasty after infection because of a high reoperation rate and difficulty in achieving solid fusion.

The use of the reverse shoulder arthroplasty for treatment of failed total shoulder arthroplasty.

BACKGROUND: This study evaluated the outcomes of patients with failed total shoulder arthroplasty (TSA) who were treated with conversion to reverse shoulder arthroplasty (RSA). MATERIALS AND METHODS: We performed a retrospective case series of 24 consecutive patients with failed TSA who were treated with conversion to RSA. Twenty-two patients (16 women, 6 men) had a minimum 2-year clinical and radiographic follow-up. The average age at the time of revision was 68 years (range, 51-84 years). Indications for conversion to RSA included failure of TSA from glenohumeral instability in 19, mechanical failure of the humeral or glenoid component in 10, and infection in 2. RESULTS: The median total American Shoulder and Elbow Surgeons score improved from 38.5 preoperatively to 67.5 (P < .001). Visual analog scale pain scores decreased from 5 to 1.5 (P < .001), and function improved from 2 to 6.5 (P < .001). The median Simple Shoulder Test improved from 1 to 5 (P = .006). Forward flexion improved from 50° to 130° (P < .001), abduction from 45° to 100° (P < .001), and external rotation from 12.5° to 49.5° (P = .056). Internal rotation improved from a spinal level of S2 to L3 (P = .064). Fourteen patients rated their outcome as excellent, 3 as good, 3 as satisfactory, and 2 as unsatisfactory. The overall complication rate was 22.7% (5 of 22). CONCLUSION: RSA can be an effective treatment for failed TSA by decreasing pain and improving shoulder function. However, RSA in the revision setting is associated with a higher complication rate.

Effectiveness of magnetic resonance imaging in detecting partial and complete distal biceps tendon rupture.

PURPOSE: A magnetic resonance imaging (MRI) scan of the elbow is often obtained to confirm the clinical suspicion of a distal biceps tendon rupture. The goal of this study was to evaluate the effectiveness of MRI in diagnosing partial and complete distal biceps tendon ruptures as determined at the time of surgery. METHODS: We identified 22 partial and 24 complete distal biceps tendon ruptures operated on by a single surgeon. The preoperative MRIs of these patients were obtained, along with MRIs of the elbow in 10 asymptomatic individuals. Two musculoskeletal radiologists read each MRI without knowledge of the diagnosis or the surgical findings. Their interpretations were compared with the intraoperative findings and the results were statistically analyzed. RESULTS: The overall sensitivity and specificity of MRI were 92.4% and 100%, respectively, in detecting distal biceps tendon ruptures. The sensitivity and specificity of MRI for complete tears were 100% and 82.8%, respectively. The sensitivity and specificity of MRI for partial tears were 59.1% and 100%, respectively. CONCLUSIONS: Magnetic resonance imaging is an effective tool for diagnosing distal biceps tendon ruptures. Although MRI is extremely sensitive in diagnosing complete tears, it is substantially less sensitive in diagnosing partial tears. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

Is a formal physical therapy program necessary after total shoulder arthroplasty for osteoarthritis?

HYPOTHESIS: A retrospective analysis was conducted of 2 consecutive groups of patients undergoing total shoulder arthroplasty (TSA) for primary osteoarthritis. One group was treated with formal physical therapy (PT), and one group was treated with home-based, physician-guided PT. We hypothesized that patients with a formal postoperative PT protocol would have significantly better postoperative clinical outcomes than patients with no formal PT. METHODS: Group A (43 patients) had a standard PT program. Group B (38 patients) had a home-based, physician-guided PT program. Clinical outcomes (preoperatively, 3, 6, and 12 months and most recent follow-up) were analyzed. A minimum sample size of 31 patients gives power to detect a 10-point American Shoulder and Elbow Surgeons (ASES) score (alpha=0.05, beta=0.80). RESULTS: ASES and Simple Shoulder Test (SST) scores significantly improved in both groups at all follow-up periods. Forward flexion and abduction were significantly improved in group B at all time points, whereas an initial improvement in forward flexion and abduction in group A was lost at final follow-up. There were no significant differences in final ASES or SST scores between groups at final follow-up. However, forward flexion, abduction, and the Short Form-36 physical component summary in group B were significantly better than group A at final follow-up. No significant improvements in internal rotation or SF-36 mental component summary were seen within or between the groups at final follow-up. Overall, there was no difference in patient satisfaction, with 88% satisfaction in group A and 95% satisfaction in group B (chi(2)=0.471, P=.4924). CONCLUSIONS: A home-based, physician-guided therapy program may provide adequate rehabilitation after TSA, allowing for a reduction in cost for the overall procedure.

Ocular abnormalities in mice lacking the immunoglobulin superfamily member Cdo.

Vertebrate eye development requires a series of complex morphogenetic and inductive events to produce a lens vesicle centered within the bilayered optic cup and a posteriorly positioned optic stalk. Multiple congenital eye defects, including microphthalmia and coloboma, result from defects in early eye morphogenesis. Cdo is a multifunctional cell surface immunoglobulin superfamily member that interacts with and mediates signaling by cadherins and netrins to regulate myogenesis. In addition, Cdo plays an essential role in early forebrain development by functioning as coreceptor for sonic hedgehog. It is reported here that Cdo is expressed in a dynamic, but dorsally restricted, fashion during early eye development, and that mice lacking Cdo display multiple eye defects. Anomalies seen in Cdo(-/-) mice include coloboma (failure to close the optic fissure); failure to form a proper boundary between the retinal pigmented epithelium and optic stalk; defective lens formation, including failure to separate from the surface ectoderm; and microphthalmia. Consistent with this wide array of defects, developing eyes of Cdo(-/-) mice show altered expression of several regulators of dorsoventral eye patterning, including Pax6, Pax2, and Tbx5. Taken together, these findings show that Cdo is required for normal eye development and is required for normal expression of patterning genes in both the ventral and dorsal domains. The multiple eye development defects seen in Cdo(-/-) mice suggest that mutations in human Cdo could contribute to congenital eye anomalies, such as Jacobsen syndrome, which is frequently associated with ocular defects, including coloboma and Peters' anomaly.

Expression of the boc gene during murine embryogenesis.

BOC is a receptor-like protein that, with the related factor CDO, belongs to a newly recognized subfamily within the immunoglobulin superfamily of cell-surface molecules. BOC and CDO form complexes that positively regulate myogenesis in vitro. To gain a better understanding of the role of boc during vertebrate embryogenesis and whether it could cooperate with cdo in vivo, we carried out an extensive in situ hybridization analysis of boc expression in mouse embryos from E7.0 to E17.5. Our results show that boc is widely expressed during murine embryogenesis, in a spatially and temporally restricted pattern. Overall, the highest levels of boc expression are detected between E10.5 and E15.5, with the strongest signals observed in the developing musculoskeletal and central nervous systems. At late stages of development, boc expression becomes more restricted and is limited primarily to regions harboring proliferating cells, undifferentiated cells, or both. This expression pattern is strikingly similar to that described for cdo (Mulieri et al., 2000). The overlapping expression patterns of cdo and boc in vivo, combined with the promotion of myogenesis by CDO/BOC complexes in cultured cells, strongly suggests that these proteins play a role together in the determination, differentiation, or both, of numerous cell types during vertebrate embryogenesis.

BOC, an Ig superfamily member, associates with CDO to positively regulate myogenic differentiation.

CDO is a cell surface receptor-like protein that positively regulates myogenic differentiation. Reported here is the identification of BOC, which, with CDO, defines a newly recognized subfamily within the immunoglobulin superfamily. cdo and boc are co-expressed in muscle precursors in the developing mouse embryo. Like CDO, BOC accelerates differentiation of cultured myoblast cell lines and participates in a positive feedback loop with the myogenic transcription factor, MyoD. CDO and BOC form complexes in a cis fashion via association of both their ectodomains and their intracellular domains. A soluble fusion protein that contains the entire BOC ectodomain functions similarly to full-length BOC to promote myogenic differentiation, indicating that the intracellular region is dispensable for its activity in this system. Furthermore, a dominant-negative form of CDO inhibits the pro-myogenic effects of soluble BOC, suggesting that BOC is dependent on CDO for its activity. CDO and BOC are proposed to be components of a receptor complex that mediates some of the cell-cell interactions between muscle precursors that are required for myogenesis.