Arthroscopic Management of Traumatic Shoulder Dislocations
Shoulder dislocation can be classified into one of two types:
- TUBS: Traumatic, Unidirectional, Bankart, Surgery
- AMBRI: Atraumatic, Multidirectional, Bilateral, Rehabilitation, Shift1
The great majority of TUBS are anterior dislocations (98 per cent in Rowe's2 series of 500), in whom a Bankart lesion is present in 85 per cent. The treatment of recurrence in this group is surgery.
AMBRI is a smaller group, usually initiated without trauma, often multidirectional (anterior, inferior and posterior), occurring in patients with generalized joint laxity, the opposite shoulder usually being loose and demonstrating a sulcus sign. These patients should not be operated upon. Treatment initially consists of a programme of supervised shoulder strengthening exercises. If the shoulder does not respond to such a programme, the patient should be referred on to a shoulder specialist to consider a capsular shift operation. There is no place for arthroscopic repair in these patients.
Two large studies have been performed on the incidence of recurrent dislocation following traumatic anterior dislocation (Figure 9.1). We have already seen (Chapter 6)
Figure 9.1 Incidence of recurrence following dislocation according to age at first dislocation. Data from Rowe and Hovelius.2,3
that there is a spectrum of both Bankart lesions (Figure 9.2) and Hill-Sachs lesions (Figure 9.3), and it is likely that the severity of damage to the anterior capsular structures is related to the number of recurrent dislocations.
Figure 9.2 Bankart lesion of the glenoid labrum IGHL complex.
Figure 9.3 Hill-Sachs osteochondral lesion in the back of the humeral head.
A concept of anterior traumatic dislocation is where the aim of surgery is to identify precisely the pathology responsible for dislocation and to perform a selective repair: 'Not all shoulder instabilities are created equal, nor are they treated the same' (Johnson).