Abstract
Purpose: Centred degeneration of the shoulder joint is defined as a degeneration of the glenohumeral surfaces without ascension of the humeral head. We investigated the influence of partial or full thickness rotator cuff tears and/or fatty degeneration of the supraspinatus on the results of total shoulder arthroplasty.
Material and methods: During a multicentric review of 766 cases of centred degeneration of the shoulder joint treated with the Aequalis prosthesis, we identified 555 shoulders in 478 patients with an interpretable preoperative arthroscan. All patients were reviewed with a minimum follow-up of two years (mean 3.6 years). Constant score and radiological findings were recorded. We identified 41 shoulders with partial tears of the supraspinatus and 42 shoulders with full-thickness tears of the supraspinatus alone. Moderate fatty degeneration was observed in 90 shoulders (≤ 2) and severe fatty degeneration of the infraspinatus or the subscapularis (> 2) in 15. We analysed the Constant scores, subjective results, radiological results, and rate of complications in each of these populations.
Results: Rotator cuff tears involving the supraspinatus alone did not have a destabilising effect, the head of the humerus did not influence the postoperative result assessed by the overall Constant score, motion in all planes, subjective result, radiological result, or rate of complications. There was no significant difference in complication rate. Presence or not of cuff repair did not influence these results. Inversely, fatty degeneration ≥ 2 involving the infrastpinatus or the subscapularis had a significant effect, decreasing the Constant score, active external rotation, active anterior elevation, and subjective result. On the contrary, it did not influence the radiological results or the rate of complications.
Discusssion: This multicentric study confirms that the degenerated shoulder joint can remain centred with a solitary tear of the supraspinatus. This has no effect on the clinical result and does not require repair. Inversely, fatty degeneration is highly predictive of the quality of the final result.
The abstracts were prepared by Docteur Jean Barthas. Correspondence should be addressed to him at Secrétariat de la Société S.O.F.C.O.T., 56 rue Boissonade, 75014 Paris.
