An anatomical study of the fetal superior capsule of the glenohumeral joint.

INTRODUCTION: The superior part of the glenohumeral joint capsule has an intimate relationship with the tendons of the rotator cuff and the tendon of the long head of the biceps. One of the strategies currently proposed in the event of a massive cuff rupture is to reconstruct this superior capsule. The main objective of this anatomical study was to describe the superior joint capsule of the embryonic glenohumeral joint and its relationship to the tendons of the rotator cuff. HYPOTHESIS: The hypothesis was that this structure was an anatomical entity, morphologically identifiable from the embryogenesis of the joint (more pronounced tissue boundaries in the fetus). MATERIAL AND METHODS: In total, 101 continuous fetal anatomical sections (4 fetuses of 336mm), in the frontal plane, made it possible to identify and measure: diameters of the humeral head and glenoid, dimensions of the joint capsule insertion zone at the level of the greater tubercle, as well as the different thicknesses of this insertion zone. The ratios above the head of the biceps and against the superior labrum were also measured. RESULTS: At the level of its distal insertion on the greater tuberosity, the thickness of the superior joint capsule varies on average between 0.8mm laterally and 1.2mm next to the tendons of the supraspinatus and infraspinatus; the thickness is 0.9mm next to the middle part of the supraspinatus tendon (the "rotator cable" zone). For its insertion at the level of the glenoid labrum, the superior capsule measures 0.6mm thick on average. The capsule around the tendon of the long head of the biceps is 1.5mm thick on average. DISCUSSION: Here, we confirm the existence of this superior joint capsule, which can potentially be reconstructed. It is inserted on the greater tubercle covering 30 to 60% of its surface with variations in thickness. The joint capsule is fused to the supraspinatus tendon at the rotator cuff insertion area, preventing independent reinsertion of the tendon. LEVEL OF EVIDENCE: IV; anatomical study.

Superior capsular reconstruction for irreparable rotator cuff tears: Autografts versus allografts.

AIMS: Superior capsular reconstruction (SCR) is a treatment option for patients with massive irreparable rotator cuff tears. Different types of grafts from various donor sites have been described. There are no clinical studies comparing the different grafts available. The aim of this study is to compare the early clinical outcomes of patients who have undergone arthroscopic SCR with different types of grafts (allograft vs. autograft). MATERIAL AND METHODS: This study is a retrospective analysis of data collected prospectively, from patients who underwent arthroscopic SCR with either a long head of biceps autograft (LHB) (n=40) or an acellular dermal allograft (n=40), between March 2015 and April 2018. The pre- and postoperative clinical data were compared between the 2 groups, as well as the incidence and type of complications. RESULTS: All patients were monitored with a minimum follow-up of one year. Three patients (7.5%) in the autograft group, and 14 (35%) in the allograft group (p=0.005) had a complication, of which 2 (5%) and 5 (12.5%) respectively, required revision surgery (p=0.432). Linear regression ruled out any significant difference between the 2 groups, with respect to clinical scores. However, patients with a history of prior rotator cuff surgery had poorer results with regard to active elevation (ß, -29.3; p=0.020), internal rotation (ß, -3.4; p=0.003) and Subjective Shoulder Value (SSV) (ß, -17.2; p=0.023). Older patients, as well as men, are associated with poorer postoperative internal rotation (ß, -0.1; p=0.003 and ß, -1.9; p=0.039 respectively), and type D lesions are associated with poorer external rotation and postoperative SSV (ß, -11.3; p=0.012 and ß, -12.4; p=0.048 respectively), compared to type C lesions. Postoperative graft integrity was improved in the autograft group compared to the allograft group. (Grade 1: 65.8% vs. 2.9%; Grade 5: 5.3% vs. 28.6%; p<0.001). CONCLUSIONS: In both groups, clinical scores improved after SCR in patients with irreparable rotator cuff tears. Fewer complications and revisions were observed with the autograft compared to the allograft. If the LHB was still in place during surgery, its use appears valid, given the reasonable cost and low rate of complications associated with it. If absent, an allograft is also an option, considering the potential clinical improvement. LEVEL OF EVIDENCE: III; Case-control study.