Autogenous bone grafting for chronic anteroinferior glenoid defects via a complete subscapularis tenotomy approach.

INTRODUCTION: Open reconstruction of severe anteroinferior chronic glenoid defects via a complete subscapularis (SSC) tenotomy using a tricortical iliac crest bone grafting technique has been reported. The purpose of this study was to evaluate the clinical and radiological results in patients who underwent this procedure and to investigate the influence of the anterior approach on the structure and function of the SSC musculotendinous unit.

MATERIALS AND METHODS: Ten patients (two women/eight men, mean age 28.7 years) underwent reconstruction of significant chronic glenoid defects in cases of recurrent shoulder instability with significant glenoid bone loss, using a tricortical autogenous iliac crest in combination with a capsulolabral repair. The patients were followed up clinically (clinical SSC tests and signs, Constant score, Rowe score, Walch-Duplay score, WOSI, MISS), by standard radiographs (true a/p, axillary and glenoid profile view), computed tomography (graft integration, inferior glenoid area) and bilateral magnetic resonance imaging [SSC tendon integrity, cross sectional area, defined muscle diameters and signal intensity analysis (ratio ISP/upper SSC and ISP/lower SSC)].

RESULTS: After a mean follow-up of 37.9 months, the mean Constant score averaged 88.3 points, the Rowe score 89.5 points, the Walch-Duplay score 83.5 points, the MISS 80.6 points and the WOSI 82.6%. No recurrent subluxations or dislocations were observed. Clinical signs for SSC insufficiency were present in 80% of cases. Two patients had grade I and one patient grade II osteoarthritis according to Samilson and Prieto classification. CT imaging revealed a consolidated autograft in all cases with an 18.4% increase of the inferior glenoid area postoperatively (P < 0.05). No tendon ruptures were found. MR imaging revealed muscular atrophy (P < 0.05) and fatty infiltration of the SSC (P > 0.05) muscle compared to the contralateral side.

CONCLUSION: Open reconstruction of anteroinferior chronic glenoid defects via a complete SSC tenotomy using an iliac crest bone grafting technique allows an anatomic reconstruction of the anteroinferior glenoid with good and excellent clinical results. The anterior approach may lead to atrophy and fatty infiltration of the SSC muscle despite an intact tendon. However, this did not affect the results in terms of stability.