Prevalence and risk factors of scapular stress fracture after reverse shoulder arthroplasty: a multicentric retrospective study.

PURPOSE: Scapular stress fracture (sSF) is a difficult complication to treat after reverse total shoulder arthroplasty (RSA). The aim of this study was to identify the prevalence and possible risk factors in a large population. METHODS: A total of 2165 RSAs that were implanted between January 2006 and October 2017 in five hospitals were evaluated. Within this cohort, sSF was radiologically confirmed. Age, gender, surgical indication and hospital of treatment were determined for the entire cohort. A matched 3:1 case-control study was then performed to investigate several clinical and surgical variables. RESULTS: sSF occurred in 3.1% (63 patients), with a median time interval of five months post-operative [IQR = 9, range: (1-79)]. Within the entire cohort, females (OR = 2.99) and rotator cuff arthropathy (RCA) (OR = 2.79) were more prone to this complication. Age had little influence (OR = 1.03). After exclusion, fifty-five eligible cases were matched to 165 controls based on hospital, gender, age and surgical indication. After univariable analysis, significance was obtained for osteopenia (P = 0.037), osteoporosis (P = 0.032), surgical approach (P = 0.002) and peri-operative acromioclavicular (AC) joint surgery (P = 0.035). Multivariate analysis demonstrated that osteopenia (OR = 3.94), osteoporosis (OR = 2.85) and a deltopectoral approach (OR = 3.70) were independent risk factors. CONCLUSION: According to our findings, older women with poor bone quality and a history of RCA suffered more frequently from sSF. Anterolateral approach during surgery was a surgical protective factor, possibly due to the mobilization of the acromioclavicular joint. Although this study indicates who is at risk for sSF, further investigation for prevention of sSF in these patients is necessary.

Arthroscopic treatment of the young degenerative shoulder joint ; is there a role for interpositioning arthroplasty ?

We evaluate our experience with arthroscopic interpositioning arthroplasty as a treatment of the young degenerative shoulder joint. Between 2007 and 2009 ten patients were treated with either a dermal allograft or a meniscal allograft. In seven patients the graft failed and within 13 months these were revised to a total shoulder arthroplasty. Three patients are still satisfied after 7 to 8 years follow-up. Biologic resurfacing of the glenoid may have a role in the management of glenohumeral arthritis in the young and active patient, but the optimal graft and pathology still need to be defined.

One-stage revision for patients with a chronically infected reverse total shoulder replacement.

We retrospectively reviewed 11 consecutive patients with an infected reverse shoulder prosthesis. Patients were assessed clinically and radiologically, and standard laboratory tests were carried out. Peroperative samples showed Propionbacterium acnes in seven, coagulase-negative Staphylococcus in five, methicillin-resistant staphylococcus aureus in one and Escherichia coli in one. Two multibacterial and nine monobacterial infections were seen. Post-operatively, patients were treated with intravenous cefazolin for at least three days and in all antibiotic therapy was given for at least three months. Severe pain (3 of 11) or severe limitation of function (3 of 11) are not necessarily seen. A fistula was present in eight, but function was not affected. All but one patient were considered free of infection after one-stage revision at a median follow-up of 24 months, and without antibiotic treatment for a minimum of six months. One patient had a persistent infection despite a second staged revision, but is now free of infection with a spacer. Complications included posterior dislocation in one, haematoma in one and a clavicular fracture in one. At the most recent follow-up the median post-operative Constant-Murley score was 55, 6% adjusted for age, gender and dominance. A one-stage revision arthroplasty reduces the cost and duration of treatment. It is reliable in eradicating infection and good functional outcomes can be achieved.

Reliability of the glenoid plane.

HYPOTHESIS: The purpose of this study was to investigate the 3-dimensional (3-D) orientation of the glenoid and scapular planes. Different definitions of the glenoid plane were used and different planes measured, and we hypothesed that the 3-D plane with the least variation would be best to define the most reliable glenoid plane. METHODS: We studied 150 CT scans from nonpathological shoulders from patients between 18 and 80. The scapular plane and 5 different glenoid planes were determined: inferior, anterior, posterior, superior, and neutral. All plane versions and inclination angles were measured. Because all examinations were done in a standardized position to the coronal, sagittal, and transverse planes of the body, the scapular plane could be defined versus the coronal, sagittal, and transverse planes of the body. RESULTS: The version (mean, 3.76) of the inferior glenoid plane showed a significantly lower standard deviation than the version of the anterior (P < .001), posterior (P=.001), and superior (P=.001) glenoid plane (ANOVA). For inclination all planes have a similar variance. The scapular plane was different between gender (P=.022) and correlated with age. CONCLUSION: This study showed that the retroversion of the inferior glenoid is reasonably constant. The osseous anthropometry of the inferior glenoid can offer a reproducible point of reference to be used in prosthetic surgery of the shoulder.