Chronic posterior dislocation of shoulder

Ravi Mittal; Siddharth Jain; Shivanand Gamanagatti

doi:10.1016/j.jcot.2022.101926

Chronic posterior dislocation of shoulder

J Clin Orthop Trauma. 2022 Jun 21:31:101926. doi: 10.1016/j.jcot.2022.101926. eCollection 2022 Aug.

Authors

Ravi Mittal¹, Siddharth Jain¹, Shivanand Gamanagatti²

Affiliations

¹ Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India.
² Department of Radiology, All India Institute of Medical Sciences, New Delhi, India.

Abstract

Purpose: Chronic posterior dislocation of shoulder (PDS) is an uncommon injury and there are very few publications describing its different injury patterns and their treatment. This study was carried out to study the associated injuries in chronic PDS, which can help to classify and guide the treatment.

Methods: We retrospectively studied 16 chronic posterior dislocation of shoulder. CT scan was used to classify the injury based on the amount of bone loss in humeral head, malunion of greater tuberosity and malunion of proximal humerus metaphysis. Visual analogue score (VAS) for pain, university of California Los Angles (UCLA) shoulder score and American shoulder and elbow surgeon (ASES) shoulder score were recorded pre operatively and at an average of 27 months post operatively.

Results: - Type A1 injury was PDS with <50% humeral head bone loss with intact greater tuberosity (GT). It was managed by modified McLaughlin procedure (MMP). Type A2 injury was PDS with >50% bone loss with intact GT. It was managed by hemi-replacement (HRA). Type B1 injury was PDS with <50% bone loss with severe GT malunion. It was managed by MMP and corrective osteotomy of GT. Type B2 injury was PDS with >50% bone loss and severe GT malunion. It was managed by reverse shoulder arthroplasty (RSA). Type C1 injury was PDS with <50% bone loss and metaphyseal malunion. It was managed by MMP and osteotomy of proximal humeral metaphysis. Type C2 injury was PDS with >50% bone loss and metaphyseal malunion. It was managed by HRA. The VAS, UCLA score and ASES score improved significantly after the surgery in all cases. There was no recurrence of the instability.

Conclusions: We concluded that chronic PDS could have fractures of tuberosities and/or proximal metaphysis in addition to bone loss in humeral head. The treatment is guided by all three factors-amount of bone loss in humeral head, malunion of GT and proximal humeral metaphysis. The proposed classification can help in choosing the optimum treatment out of joint salvage procedure, anatomic shoulder replacement and reverse shoulder arthroplasty.

Keywords: Chronic; Fracture dislocation proximal humerus; Posterior shoulder dislocation; Reverse hill-sachs lesion.