These experienced surgeons were usually able to reproduce the desired anatomical relationships, but as seen in the table and in the figures below, there was some variability in surgical technique.
Postoperative radiographs of 177 cases showed 10 (5.7%) shoulders with glenoid osteolysis; 51 (28.8%) had glenoid radiolucent lines,
and 81 (45.8%) had calcar resorption.
Follow-up duration (median 40.1 vs. 27.2 months), BMI (median 27.5 vs. 30.7), and Charleston Comorbidity Index (Q3 0 vs. 1) were associated with glenoid osteolysis in bivariate analyses.
In multiple logistic regression, surgeon identity (C vs. A/B) was the only statistically significant predictor of glenoid radiolucent lines [OR 0.27, 95% CI (0.1, 0.8)]. Glenoid radiolucent lines were seen respectively in 34.6%, 39.3%, and 10.6% for patients of surgeons A, B, and C .
The authors observed calcar resorption in 46% of cases. Multivariable analysis showed surgeon identity, higher canal filling ratio, over stuffing of the humeral head and glenoid osteolysis to be independent predictors of calcar resorption. By descending importance, Surgeon C [OR 6.5 (2.0, 20.5)], humeral canal filling ratio [upper vs. lower quartile OR 2.3 (1.3, 4.0)], mediolateral humeral head deviation [upper vs. lower quartile OR 1.9 (1.0, 3.5)] and glenoid osteolysis [OR 13.5 (2.6, 71.6)] significantly predicted greater calcar resorption. Full thickness calcar resorption was seen in 3.8%, 5.2% and 18.2% of patients of surgeons A, B, and C respectively.
Effects of the individual surgeons technique are shown in the chart below.
Comment: The outcomes in this report were excellent and comparable to other reports of modern approaches to anatomic shoulder arthroplasty, including the successful application of non-augmented glenoids to address type B pathoanatomy.
This study demonstrates that even when highly experienced surgeons perform total shoulder arthroplasty, there is inter-surgeon variability in component position as well as in the rates of glenoid lucent lines and calcar resorption.
The clinical significance of this variability in component position and radiographic outcomes was not demonstrated in the two year ASES scores reported in this study. However, greater deviations from the ideal component positions and longer periods of followup may reveal effects on clinical outcome.
Some surgeons find it useful to obtain intraoperative fluoroscopy to assure the desired position.
Some surgeons may find the insertion of the glenoid component to be difficult. Excellent glenoid exposure, careful glenoid reaming and accurate drilling of the fixation holes have been shown to be critical to optimal seating of the glenoid component with the goal of minimizing radiolucencies.
The use of preoperative CT based planning was not described in this report. It is not evident that such planning would have addressed the variability described by the authors or improved the clinical outcomes.
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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).
