Glenosphere design affects range of movement and risk of friction-type scapular impingement in reverse shoulder arthroplasty.

Aims: Scapular notching is a frequently observed radiographic phenomenon in reverse shoulder arthroplasty (RSA), signifying impingement of components. The purposes of this study were to evaluate the effect of glenoid component size and glenosphere type on impingement-free range of movement (ROM) for extension and internal and external rotation in a virtual RSA model, and to determine the optimal configuration to reduce the incidence of friction-type scapular notching. Materials and Methods: Preoperative CT scans obtained in 21 patients (three male, 18 female) with primary osteoarthritis were analyzed using modelling software. Two concurrent factors were tested for impingement-free ROM and translation of the centre of rotation: glenosphere diameter (36 mm vs 39 mm) and type (centred, 2 mm inferior eccentric offset, 10° inferior tilt). Results: Glenosphere size was most predictive of increased extension and external rotation, whereas lateralization of the centre of rotation was the most predictive factor for internal rotation. A larger diameter of glenosphere combined with a 10° tilted configuration demonstrated superior values for extension and external rotation, whereas the eccentric component improved internal rotation by a mean 8.9° (standard deviation 2.7°) compared with a standard concentric glenosphere. Conclusion: Glenosphere configuration can be modified to increase range of movement in RSA. Friction-type scapular notching was most effectively reduced by use of a large-diameter glenosphere with 10° inferior tilt. Cite this article: Bone Joint J 2018;100-B:1182-6.

Progressive glenoid bone loss caused by erosion in humeral head resurfacing.

BACKGROUND: Cementless surface replacement of the shoulder represents an alternative to conventional stemmed anatomic prostheses. Glenoid erosion is a well-known complication in hemiarthroplasty. However, there is limited data concerning radiographic evaluation and prognostic factors for this phenomenon. OBJECTIVES: The aim of our study was to determine the development of glenoid erosion following shoulder resurfacing using a new measurement technique and detect potential prognostic factors. MATERIALS AND METHODS: We performed a retrospective analysis on 38 shoulders undergoing humeral head resurfacing with a mean follow-up of 65.4 ± 43 months. Clinical and radiographic evaluation followed a standardized protocol including pre- and postoperative Constant score, active range of motion, and X­rays in true anteroposterior view. Three independent observers performed measurements of glenoid erosion. RESULTS: We found good interobserver reliability for glenoid erosion measurements (intraclass correlation coefficient [ICC] 0.74-0.78). Progressive glenoid erosion was present in all cases, averaging 5.5 ± 3.9 mm at more than 5 years' follow-up. Male patients demonstrated increased glenoid bone loss within the first 5 years (p < 0.04). The mean Constant score improved to 55.4 ± 23.6 points at the latest follow-up. Younger age was correlated to increased functional outcome. Revision rate due to painful glenoid erosion was 37%. CONCLUSIONS: Glenoid erosion can be routinely expected in patients undergoing humeral head resurfacing. Painful glenoid erosion leads to deterioration in functional outcome and necessitates revision surgery in a high percentage of cases.

[Arthroscopic capsular release of the elbow]. / Arthroskopisches Kapselrelease des Ellenbogens.

Limited mobility of the elbow joint can be due to various factors, the most common of which is trauma to the elbow. In addition, limited elbow movement can be a direct cause of decreased functionality and interfere with everyday life activities. The majority of the patients can recover a functional range of motion if physical therapy is combined with a splinting regimen. However, some patients will experience continued elbow stiffness. Traditionally, open techniques have been successful in releasing the elbow joint capsule and regaining functional range of motion. Early results of arthroscopic elbow capsule release were associated with an increased rate of peripheral nerve injury. Due to technical progress and modifications, arthroscopic capsular release of the elbow is now a safe and dependable--although technically challenging--method to regain elbow motion.

[Cementless humeral head replacement for dislocation arthropathy of the shoulder joint]. / Zementfreier Oberflächenersatz bei Dislokationsarthropathie des Schultergelenks.

BACKGROUND: Only a few reports in the literature describe that total shoulder replacement provides better functional results in dislocation arthropathy than hemiarthroplasty. Nevertheless, the risk of aseptic loosening in young and active patients is high after long-term follow-up. We evaluated the results of cementless humeral head resurfacing in this group. METHODS: We evaluated 29 patients with dislocation arthropathy who had been followed up for a mean of 39 months. The mean age at the time of operation was 43.7±14.7 years. Preoperatively, cuff deficiency was seen in 11 cases. RESULTS: The mean adjusted Constant score improved from 16.8±15.2% to 78.1±21.9%. Negative prognostic factors turned out to be female sex, age, cuff tears especially of the subscapularis tendon, and previous bone block procedures. Revision was performed in five patients, and two developed painful glenoid erosion which required conversion to total shoulder arthroplasty. CONCLUSION: Cementless humeral head replacement is a viable option in the treatment of dislocation arthropathy. Revision can be performed easily since the bone stock has been preserved. On the basis of our data, humeral head replacement in patients <40 years with dislocation arthropathy offers promising short- to midterm results with an acceptable complication rate.