This 1988 case-control study from the University of Washington examined 7 TSA patients with major glenoid loosening and compared them against 16 consecutive TSA patients with intact rotator cuffs. It asked: what factors predict glenoid component failure after TSA? The study also introduced a standardized 6-class radiographic classification of glenoid status and the GHCC distance measurement.
When you see a patient with an irreparable rotator cuff tear asking about shoulder replacement, this paper is the reason you offer reverse TSA rather than anatomic TSA with glenoid resurfacing.
Neer initially did not consider rotator cuff deficiency a contraindication to unconstrained TSA. Franklin et al. Showed that 100% of glenoid loosening cases in their series had cuff deficiency, and zero intact-cuff patients failed at 5 years.
The mechanism matters clinically: superior humeral migration from cuff failure creates eccentric loads that rock the glenoid component into progressive tipping. Adding a constrained glenoid to resist this force only shifts the failure mode to catastrophic loosening at rates up to 20%.
The practical rule: glenoid resurfacing is indicated only when the cuff is intact or fully reconstructable. For the nonreconstructable cuff, this paper set the conceptual stage for reverse shoulder arthroplasty as the solution to a problem that anatomic TSA cannot solve.
This 1988 case-control study from the University of Washington examined 7 TSA patients with major glenoid loosening and compared them against 16 consecutive TSA patients with intact rotator cuffs. It asked: what factors predict glenoid component failure after TSA? The study also introduced a standardized 6-class radiographic classification of glenoid status and the GHCC distance measurement.
When you see a patient with an irreparable rotator cuff tear asking about shoulder replacement, this paper is the reason you offer reverse TSA rather than anatomic TSA with glenoid resurfacing.
Neer initially did not consider rotator cuff deficiency a contraindication to unconstrained TSA. Franklin et al. Showed that 100% of glenoid loosening cases in their series had cuff deficiency, and zero intact-cuff patients failed at 5 years.
The mechanism matters clinically: superior humeral migration from cuff failure creates eccentric loads that rock the glenoid component into progressive tipping. Adding a constrained glenoid to resist this force only shifts the failure mode to catastrophic loosening at rates up to 20%.
The practical rule: glenoid resurfacing is indicated only when the cuff is intact or fully reconstructable. For the nonreconstructable cuff, this paper set the conceptual stage for reverse shoulder arthroplasty as the solution to a problem that anatomic TSA cannot solve.