Retrospective review of 16 patients who had hemiarthroplasty for rotator cuff (cuff-tear) arthropathy. The surgeons used a slightly oversized modular head meant to articulate with the coracoacromial arch while preserving about 50% glenohumeral translation. Outcomes were graded by Neer's limited goals criteria to ask which patients do well and which fail.
When you see cuff-tear arthropathy, two structures decide whether hemiarthroplasty will work: the coracoacromial arch and the deltoid.
The humeral head has migrated superiorly and now bears against the CA arch, which is the last restraint to anterosuperior escape. Take that arch away with an acromioplasty and CA ligament release, and the prosthetic head subluxates forward and up. Every such patient failed here.
The technical pearl: oversize the head just enough to articulate with the arch, but keep about 50% glenohumeral translation. Matching the arch dimensions overconstrains the head and pushes it anterior. This is also a reason to avoid total shoulder in these patients. A superiorly migrated head eccentrically loads the superior glenoid and loosens the component through the rocking-horse effect.
Practically, do not perform a routine acromioplasty during cuff repair when only a limited repair is possible, because you may be sabotaging a future hemiarthroplasty.
Retrospective review of 16 patients who had hemiarthroplasty for rotator cuff (cuff-tear) arthropathy. The surgeons used a slightly oversized modular head meant to articulate with the coracoacromial arch while preserving about 50% glenohumeral translation. Outcomes were graded by Neer's limited goals criteria to ask which patients do well and which fail.
When you see cuff-tear arthropathy, two structures decide whether hemiarthroplasty will work: the coracoacromial arch and the deltoid.
The humeral head has migrated superiorly and now bears against the CA arch, which is the last restraint to anterosuperior escape. Take that arch away with an acromioplasty and CA ligament release, and the prosthetic head subluxates forward and up. Every such patient failed here.
The technical pearl: oversize the head just enough to articulate with the arch, but keep about 50% glenohumeral translation. Matching the arch dimensions overconstrains the head and pushes it anterior. This is also a reason to avoid total shoulder in these patients. A superiorly migrated head eccentrically loads the superior glenoid and loosens the component through the rocking-horse effect.
Practically, do not perform a routine acromioplasty during cuff repair when only a limited repair is possible, because you may be sabotaging a future hemiarthroplasty.