Anterior shoulder dislocation with avulsion fracture of the greater tuberosity results in reliable good outcomes after closed reduction

Abstract

Background: Avulsion of the greater tuberosity (GT) due to traumatic anterior shoulder dislocation (ASD) is a commonly observed fracture pattern. After closed reduction of the dislocated humerus, the GT typically reduces itself into its anatomic position enabling the patient to undergo conservative treatment. The aim of this study was to retrospectively review a consecutive series of patients with conservatively treated GT avulsion fractures after closed reduction of an ASD and analyze radiographic outcome, shoulder function and glenohumeral stability and the conversion rate to surgical treatment.

Methods: All patients who underwent closed reduction of a GT avulsion fracture after ASD with the primary intention of conservative treatment between 2017 and 2022 were included. Complications (i.e. conversion to surgical treatment), shoulder function assessed with the American Shoulder and Elbow Surgeons score and subjective shoulder value, instability assessed with the Western Ontario Shoulder Instability score, radiological impingement (greater tuberosity index = GTI and impingement index = II) and GT fracture pattern were assessed as outcome measurements.

Results: A total of 29 patients (mean age 44 years, 27% female) with a mean follow-up of 32.6 (range, 8-96) months were enrolled. Seven patients (24%) underwent surgery due to secondary displacement (n = 4, 14%) or impingement symptoms (n = 3, 10%). All patients who underwent secondary surgery showed a multifragmentary fracture pattern of the GT. Shoulder stiffness (n = 7) and neuropraxia of the axillary nerve (n = 3) were observed temporarily and resolved during the follow-up period. The American Shoulder and Elbow Surgeons and subjective shoulder value of the conservatively treated patients at the last follow-up was 89.2 ± 19.1 respectively 86 ± 18.2%. No recurrent glenohumeral dislocation was documented. The mean Western Ontario Shoulder Instability score at last follow-up was 8(0-71). The mean GTI decreased from 1.2 ± 0.1 after ASD to 1.1 ± 0.1 at the last follow-up (P = .002). The mean II decreased from 0.6 ± 0.5 after ASD to 0.4 ± 0.3 at the last follow-up (P = .110).

Conclusion: The GT avulsion fragment reduces typically into a close to anatomic position after closed reduction and the GTI even improves with further conservative treatment over time. Close radiological follow-up is necessary to rule out secondary displacement which occurs typically in a multifragmentary fracture pattern. Patients without the need for surgery showed good clinical outcomes without recurrence of glenohumeral instability.

Keywords: Anterior shoulder dislocation; Anterior shoulder fracture dislocation; Conservative treatment; Fracture avulsion greater tuberosity; Greater tuberosity dislocation; Greater tuberosity fracture.

Figure 1

ap radiographs of the glenohumeral joint of two patients showing how the greater tuberosity avulsion fragment after ASD reduces into a close to an anatomic position after closed reduction. From the Left to the Right: (A) radiograph after ASD, (B) check-up after closed reduction, (C) last follow-up. After closed reduction: GTI: 1.32, II: 1.07. At final follow-up GTI:1.15, II: 0.49. Formula: GTI=Rt/Rh; II=(Rt-Rh)/(Ra-Rh). ASD, anterior shoulder dislocation; GTI, greater tuberosity index; II, impingement index; Rh, Radius of a circle tangent to humeral articular surface; Rt, Radius of a circle tangent to the greater tuberosity; Ra, Radius of a circle tangent to the undersurface of the acromion.

Figure 2

(A) ap x ray showing ASD with avulsion fracture of GT. (B) ap x ray after closed reduction with reduced GT fragment and HHPS. SSV 0%. (C) 6 weeks after ASD and closed reduction with severe HHPS and healed GT fragment. SSV:15%. (D) ap x-ray 10 months after ASD and closed reduction showing recentered humeral head and normalized impingment indices. SSV: 99%. (E-H) photographic documentation of ROM at last follow-up (10 months). Flexion 160° (E and F), external rotation 70° (G). internal rotation L3 (H). ASD, anterior shoulder dislocation; GT, greater tuberosity; SSV, subjective shoulder value; HHPS, humeral head pseudosubluxation; ROM, range of motion.