These authors conducted a systematic review of studies evaluating reverse total shoulders (RTSA) that reported the type of prosthesis as well as active postoperative ROM at a minimum of 12 months after surgery. Preoperative range of motion, postoperative range of motion and the difference in range of motion was compared between RTSA humeral components with cup inclination 135° and 155°.
Sixty-five studies with 3302 patients (3434 shoulders; 1211 in the 135° group and 2223 in the 155° group) were included.
Patients in the 135° group had significantly greater improvement in external rotation (P < .001) and significantly more overall external rotation compared to the 155° group. No significant difference were found between the 135° and 155° groups in range of motion improvements in forward elevation or abduction.
Comment: As the authors point out, the 135° neck shaft angle humeral prosthesis is usually used with a laterally offset glenosphere
whereas the 155° humeral prosthesis is usually used with a medialized glenosphere
So the effects of the humeral neck shaft angle may not be separable from the effects of the glenosphere design.
While the authors do not suggest why the 135° neck shaft angle humeral prosthesis is associated with more rotation, it is possible that the steeper angle and the lateral glenosphere offset reduce the risk of humeral abutment against the glenoid in external rotation as suggested by this axillary view.
===
Use the "Search" box to the right to find other topics of interest to you.
You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'
You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'
