Posterior augmented glenoid designs preserve more bone in biconcave glenoids.

BACKGROUND AND HYPOTHESIS: Total shoulder arthroplasty is recommended treatment for severe osteoarthritis of the glenohumeral joint, which often results in excessive posterior wear. Two recent glenoid components with posterior augments have been designed to correct excessive posterior wear and retroversion. Our primary hypothesis was that posterior augmented glenoid designs require less bone removal than a standard glenoid design. METHODS: Ten arthritic scapulae classified as Walch B2 glenoids were virtually implanted with standard, stepped, and wedged components. The volume of surgical bone removal, the maximum reaming depth, and the portion of the implant surface in contact with cancellous vs. cortical bone were calculated for each implant. RESULTS: The neoglenoid made up an average of 65% ± 12% of the glenoid width. Mean surgical bone volume removed was least for the wedged (2857 ± 1618 mm(3)) compared with the stepped (4307 ± 1485 mm(3); P < .001) and standard (5385 ± 2348 mm(3); P < .001) designs. Maximum bone depth removed for the wedged (4.2 ± 2.0 mm) was less than for the stepped (7.6 ± 1.2 mm; P < .001) and standard (9.9 ± 3.2 mm; P < .001). The mean percentage of the implant's back surface supported by cancellous bone was 18.2% for the standard, 8.8% for the stepped (P = .02), and 4.3% for the wedged (P = .01). DISCUSSION: Both augmented components corrected glenoid version to neutral and required less bone removal, required less reaming depth, and were supported by more cortical bone than in the standard implant. The least amount of bone removed was with the wedged design.

Suture capsulorrhaphy versus capsulolabral advancement for shoulder instability.

PURPOSE: The purpose of this study was to test the strength of a suture capsulorrhaphy repair versus a capsulolabral repair with knotless suture anchors in a cadaveric model with anteroinferior shoulder instability. METHODS: Fourteen cadaveric shoulders were tested with either a suture capsulorrhaphy to the intact labrum or a capsulolabral advancement using a knotless suture anchor into the glenoid. Specimens were translated with the shoulder in an abducted, externally rotated position to failure. RESULTS: The capsulolabral advancement showed a significantly higher load to failure than did the suture capsulorrhaphy group (P = .030). CONCLUSIONS: Capsulolabral advancement with suture anchors may offer greater initial strength when compared with a suture capsulorrhaphy. In the setting of shoulder instability without evidence of a labral tear, the capsulolabral advancement technique may be considered biomechanically superior. CLINICAL RELEVANCE: In the setting of shoulder instability due to capsular insufficiency, the capsulolabral advancement may be considered biomechanically superior to a traditional suture capsulorrhaphy.