Treatment of chronic dislocations of the shoulder by reverse total shoulder arthroplasty: a clinical study of six cases

Chronic shoulder dislocation is a disabling pathology that aggravates with the age of the lesion and with recurrences after failed open or closed reduction. The severe alteration of the anterior rim of the glenoid and of the subscapularis tendon limits the therapeutic options. This study presents an original operative procedure for stabilization by means of a constrained reverse arthroplasty, with a minimum follow-up of 12 months, in six cases. In 2005 and 2006, six patients were referred to our Shoulder Service for irreducible shoulder fracture-dislocations that recurred after closed or open reduction at 4 and 78 months from the original injury. The patient's age ranged between 58 and 82 years. There were no neurological complications and the deltoid was functional in all cases. All the patients were treated surgically. In all cases, the destruction of the glenoid, the bone defect of the humeral head and the poor quality of the subscapularis compromised all attempts for a conservative surgery. The option of treatment was for a retentive reverse total shoulder arthroplasty (RTSA) associated with a subscapularis release and repair. Shoulder stabilization by retentive RTSA generated an improvement of the mobility, stability and of the shoulder scores, and the quality of the daily living in all the cases presented. The procedure resulted in important pain relief and in the stabilization of the joint. The eventual restrictions in the range of motion are perfectly accepted by the subjects as an alternative to a preoperative "no-win" situation. Chronic shoulder dislocations are rare. The option of the constraint RTSA in these cases may be an acceptable solution when the bone stock is limited and when the subscapularis tendon is affected, retracted, shortened or compromised. A preoperative bone scanner is useful for defining the glenoid morphology and for planning the orientation of the implant and/or an eventual bone grafting. The number of cases in this study is small, but the originality of this option makes this idea suitable for debate.