[Results of the surgical repair of the rotator cuff. Radio-clinical correlation].

INTRODUCTION: This study was undertaken to evaluate the functional results of rotator cuff tear repair.
MATERIAL AND METHODS: This retrospective study concerned 108 shoulders operated with a minimal follow up of 1 year (mean 5.5 years). The average age of this masculine population was 55 years. The rotator cuff tear involved: 39 times the supra-spinatus, 59 times the supra-spinatus and infra-spinatus, 6 times the supra and infra-spinatus and the teres minor, 4 times the supra-spinatus and superior part of the sub-scapularis. All these patients were reviewed using the Constant's score. The functional results were compared with an ultrasonographic study and a radiographic protocol including 5 views. Muscle strength was measured objectively with the aid of an isokinetics testing (Cybex II).
RESULTS: The results were satisfactory concerning pain (67 per cent did not suffer anymore) daily activity (78 per cent experienced a slight disability) and mobility (92 per cent of the patients had an anteflexion > 120 degrees and 82 per cent an external rotation > 40 degrees). Concerning strength, the results were variable and related to the posterior extension of the tear. Most of the patients complained of weakness (mean objective deficit of strength = 25 per cent), specially a disability during repetitive over head activities. The radiographic protocol analysed the humeral head position (16 per cent of spontaneous acromio-humeral interval narrowing on the standard X Ray and 43 per cent of dynamic narrowing on Leclercq view). The spontaneous narrowing was correlated with a severe omarthrosis and a re-rupture of the rotator cuff. All these re-ruptures involved an infraspinatus lesion. Dynamic narrowing, with an acromial interval < 7 mm, were seen in 71 per cent of the patients with posterior extension of the rotator cuff tear explaining the poor final result; the ultrasonographic assessment found a thinning (75 per cent of patient) and a heterogeneity in the infraspinatus even after repair. We found 14 re-ruptures and 6 ultrasonographic disorganised structures. DISCUSSION: A well preserved external rotation and a centred head gave good result because they were associated with the integrity of the infra-spinatus, essential to the muscular balance of the rotator cuff and necessary for the dynamic and static centering of the humeral head. In 71 per cent of the cases, the suture of the posterior cuff tear did not allow a good dynamic position of the humeral head. A spontaneous narrowing (static view) of the acromio-humeral interval was in relation with a re-rupture which evolved to omarthrosis. A dynamic narrowing with a Leclercq radiograph was associated with a functional deficit after rotator cuff repair.
CONCLUSION: Humeral head stabilisation, supplied by posterior muscles of the rotator cuff, is essential in prevention of omarthrosis and in recovery of good strength. In several specific cases, we think that the transfer of an external rotator muscle, with a good humeral head stabilization action, may restore strength.