[Inveterated posterior glenohumeral dislocation treated surgically from the anterior approach]

The aim of the study is to remind the medical community of the occurrence of rare dorsal glenohumeral dislocations and of the need to pay increased attention to radiographic and clinical examination in the patients in whom signs of this injury are also supported by medical history. When this dislocation becomes a chronic disorder, it can frequently be managed only by surgical intervention. The treatment algorithm used at the authors' institutions is described.

In the period from 2000 to 2008, a total of l7 patients (9 women and 8 men) with an average age of 65.5 years (51 to 89 years) had surgery for inveterated dorsal glenohumeral dislocation. The average injury-surgery interval was 5.6 weeks (1 to 18 weeks). The average follow-up was 38 months (101 to 13 months).

Surgery was performed via an anterior deltoideopectoral approach. Under pathological conditions, the subscapular muscle was identified. When a large reverse Hill-Sachs defect was present, the lesser tuberosity with the subscapular tendon was osteomited (10 patients). After scar and granulation tissue had been removed, the humeral head was reduced. Using Neer's modification of the McLaughlin procedure, the excised lesser tuberosity fragment was transferred into the antero-medial defect in the humeral head and fastened with a screw. In the case of an unstable humeral head, this was held in the reduced position by two Kirschner wires either passed through the acromion or fixed to the glenoid (11 patients). The arm was immobilized in a brace for four weeks. Then the wires were removed and rehabilitation was started with avoidance of internal rotation.

None of the patients had recurrent dislocation. All were satisfied with the outcome and capable of resuming their daily activities sufficiently. Six patients complained of occasional pain. The average value of active elevation was 113° (40° to 160°). Reduced muscle strength in abduction, as compared with the contralateral arm, was observed in two patients. Injury to the axillary vein was recorded in one patient. Two patients had a large haematoma of the arm with swelling of the whole extremity. Two of the 11 patients treated with Kirschner wires developed infection around the wires that healed after their removal at four weeks after surgery. DISCUSSION The open reduction and stabilization of a posterior inveterated glenohumeral dislocation can be regarded as a rare procedure performed only occasionally even in specialized institutions. The international literature also provides information on only a few tens of such cases over a number of years. Causal procedures, performed through both an anterior and posterior approach, as well as extrafocal (rotational) osteotomy have been recommended. Currently, surgery from an anterior approach is preferred, because a reverse Hill-Sachs defect, if present, can be managed either by transfer of the lesser tuberosity with the subscapular tendon or by massive allograft. CONCLUSIONS The authors' experience suggests that Neer's modification of the McLaughlin procedure is the optimal treatment for posterior inveterated glenohumeral dislocation with an anteromedial defect of the humeral head. The excision of the lesser tuberosity with the subscapular tendon provides good access to the shoulder joint and thus allows for its reliable reduction. The fastening of a tuberosity fragment into the compression defect resolves one of the major risks for recurrent dislocation, without necessity to use allogenic material. Transfixation of the humeral head with Kirschner wires for four weeks is a reliable method of holding the head in the glenoid without risk of significantly restricting shoulder motion in the future.