HOW I DO IT

Open ‘Bankart’ repair for recurrent anterior dislocation of the shoulder

M. SUHAIB SAIT, LARS NEUMANN and W. ANGUS WALLACE
Nottingham Shoulder and Elbow Unit, City Hospital, Nottingham , U.K.

“...the frequently recurring dislocation from trivial causes is a great and serious disability” (AS Blundell Bankart, 1923)

Keywords: shoulder dislocation, recurrence, operation, stabilisation

J.R.Coll.Surg.Edinb., 44, August 1999, 245-50

INTRODUCTION

The young patient, under 22 years old, presenting with a dislocated shoulder due to trauma such as a rugby injury, is at a high risk of between 47% and 60% of sustaining another dislocation following a further relatively trivial injury.^1,2 The reason for this is now felt to be due to the ‘Bankart lesion’ (Figure 1). This lesion is seen in over 85% of cases after a traumatic anterior dislocation.³ To understand the ‘Bankart lesion’ it is necessary to appreciate the anatomy of the ligaments, which stabilise the shoulder. These are shown in Figure 2, where the ligaments are identified as thickenings of the capsule of the shoulder. The most important is the inferior gleno-humeral ligament, which is attached medially to the inferior half of the anterior glenoid labrum. At the time of the original injury, the humeral head, when it is forced out anteriorly and inferiorly, first stretches the anterior capsule and the inferior glenohumeral ligament. Then, as a result of traction, the fibrous labrum is pulled off from the inferior half of the anterior rim of the glenoid. This traumatic detachment of the glenoid labrum has been called the ‘Bankart lesion’ after Blundell Bankart, who first described it⁴, although surgical repair of the lesion may actually have first been carried out by Perthes in 1906.⁵ The instability in this case is usually in one direction, it is post- traumatic, and is best treated with an anterior stabilisation procedure to the shoulder. We have now used a modification of Rowe’s version of the Bankart operation³ for over 10 years.

Figure 1: Diagram of the Bankart lesion with detachment of the inferior half of the anterior glenoid labrum

Figure 2: The anterior ligaments of the gleno-humeral joint

INSTRUMENTS

It is essential for this operation that suitable retractors are available. We use either the Atlantech shoulder retractor (available from Atlantech Medical Devices (UK) Ltd) or the Kolbel self retaining retractor (available from Waldemar Link, Hamburg) (Figure 3) to improve the surgeon’s access to the shoulder joint. In addition, we use two long handle Kolbel scapular neck retractors (Figure 4) (available from Waldemar Link, Hamburg) for retracting the divided subscapularis muscle. An extra pair of hands will not compensate for the absence of these surgical instruments. The Bankart operation has been considerably simplified by using suture anchors as it is no longer necessary to create tunnels for sutures passing from the anterior glenoid rim through the anterior glenoid joint surface. We use the Mitek G-II anchor (Mitek/Ethicon) as it simplifies the operation, requires minimal instrumentation and its pull out strength exceeds the strength of the No. 2 Ethibond sutures attached to it (Figure 5).

From left to right

Figure 3: The Kolbel self-retaining shoulder retractor with detachable blades

Figure 4: The Kolbel subscapularis long handle retractors

Figure 5: The Mitek GII anchor threaded with No 2 Ethibond suture and mounted on its introducer

PATIENT POSITION

The operation is performed under a general anaesthetic and the patient is placed in the deck chair position. A one litre saline bag is placed under the medial border of the scapula of the shoulder which is being operated to support the shoulder and to push the scapula forward. This facilitates access to the glenoid rim and allows a better view in the restricted surgical field. The whole of the upper limb is prepared with antiseptic and draped free.

PROCEDURE

Examination under anaesthesia

An examination under anaesthesia is necessary to establish the exact nature of the instability. The ideal indication for the Bankart repair is a true traumatic unidirectional instability, although some capsular shift can be built into the procedure to cater for cases with some degree of inferior laxity. Other types of instability - in particular atraumatic or multidirectional - are better treated by other procedures and may even be worsened by a Bankart repair, if it is carried out anteriorly when the main instability is posteriorly. A diagnostic arthroscopy can be useful to confirm the presence and extent of a Bankart lesion or other intraarticular pathology (Figure 6).

Figure 6: A Bankart lesion seen from inside the shoulder joint at arthroscopy. Note how the hook is lifting the labrum away from the anterior glenoid rim.

Incision

A standard anterior deltopectoral incision is used. The line of the incision is from 1- 2 cms inferior to the tip of the coracoid process extending about 7cm towards the anterior axillary fold (Figure 7).

Figure 7: The skin incision for the surgical approach to the shoulder

Approach

The deltopectoral groove is identified by a ‘yellow stripe’ which can be seen on the surface of the anterior muscles . The cephalic vein is sought lying in the groove (Figure 8) but, if it is difficult to identify, it will be found most easily distally where it is more superficial. When dissected out the vein can be reflected either medially or laterally. The interval between the deltoid and the pectoralis major is developed and the conjoined tendon arising from the coracoid process is identified.

Figure 8: The cephalic vein found lying in the delto-pectoral groove

The conjoined tendon is now dissected free from the underlying subscapularis (Figure 9). Recently, we have retracted the conjoined tendon medially with the help of the self retaining retractors (Figures 3 and 13). In the past, we often performed a coracoid osteotomy to obtain better exposure. With good retractors this is only occasionally necessary, but it is facilitated by pre-drilling the coracoid (Figure 10) before the osteotomy, 2cm from the tip of the coracoid, is carried out.

Figure 9: The conjoined tendon is now identified and mobilised from the underlying subscapularis

Figure 10: In the rare cases where the coracoid is detached with an osteotomy 2 cm from its tip, it should be pre-drilled and tapped prior to being osteotomised

Division of subscapularis

The subscapularis muscle and its tendon is identified by externally rotating the arm. Two No. 2 Ethibond stay sutures are used to control the medial musculotendinous tissues. With the arm in external rotation careful division of the subscapularis tendon is carried out about 1- 2 cms from its insertion just lateral to the musculotendinous junction (Figure 11). The subscapularis muscle is then stripped off the anterior capsule, which is left undamaged, and retracted medially. Laterally, the tendon may blend with the capsule. More medially, a clear tissue plane is present, which allows easier separation of the subscapularis muscle from the underlying capsule.

Figure 11: With the arm in external rotation, the subscapularis tendon is divided vertically about 2 cms from its insertion, as shown

Capsulotomy

With the assistance of a curved long handle retractor placed on the neck of the scapula (Figure 4) the glenoid rim can be palpated. The axillary nerve lies just inferior to the shoulder joint capsule (Figure 12). A blunt ringhandled retractor is slipped down on the anterior capsule and passed inferior to the shoulder, retracting the inferior structures including the axillary nerve away from the capsule, thereby protecting this important nerve which lies only 5-10mm below the inferior capsular fold. Using a long handled scalpel with a size 15 blade, the capsule is now divided at the level of the anterior glenoid rim (never medial to the rim as this will lead to tightness and restricted external rotation), and a Bankart retractor is placed within the joint to retract the humeral head away from the glenoid. The anterior glenoid rim is now inspected and cleared of fibrous tissue, using bone nibblers and an osteotome to expose bleeding bone. In 30% of cases, a malunited glenoid rim fracture is identified, and in those cases the fragment may have to be excised.

Figure 12: The surgeon needs to be aware of the axillary nerve, which lies 5 -10mm inferior to the capsule of the shoulder. It can be seen here as it passes from the brachial plexus in front to the deltoid muscle posteriorly and laterally. This nerve is protected by passing a ring handled spike along the inferior capsule and retracting the nerve downwards

Anchor sutures

Once the glenoid rim has been prepared, three drill holes are made on the glenoid rim at the osteochondral junction, or just on the joint surface. If the anchors are placed too far medially, a residual Bankart lesion will be the result. The placement of the drill holes is critical. These will accommodate the three Mitek anchor sutures. The anchors should be distributed along the glenoid rim to allow all the detached capsule to be securely fixed to bone. The lower anchor should be introduced as low as possible, and the remaining two about 1 to 1.5 cm apart. The recommended positions for three anchor sutures for a right shoulder are 5.30 to 6 o’clock, at 4.30 and at 2 .30 to 3 o’clock (Figure 13)

Figure 13: The recommended positions for the anchor sutures for a right shoulder are 5.30, 4 o’clock and 2.30. Note the use of the Atlantic shoulder retractor

Capsular obliteration of the Bankart lesion

After positioning the arm in 45^o of external rotation, the sutures are placed one at a time. The suture is allowed to slide through the eye of the anchor. One strand from each suture is taken inside out through the medial rim of the detached capsule. This distal placement of the sutures in the capsule allows a slight proximal shift of the capsule during the repair in cases with inferior laxity. Care must be taken to avoid taking too large a bite of the capsule, as this will shorten the capsule and restrict external rotation. With all three sutures passed through the capsule, a trial reduction can be carried out. The surgeon reduces the capsule onto the glenoid rim, keeps the sutures taught and externally rotates the arm until he feels the capsule lifting off the glenoid rim. If the surgeon cannot achieve 45^o of external rotation, the sutures need to be repositioned in the capsule by taking a smaller bite of capsular tissue. If the shoulder externally rotates past 45^o before the capsule lifts off, it may be necessary to take a slightly bigger bite of capsule. The sutures are now tied, thus repairing the anterior capsule onto the glenoid rim (Figure 14). The two strands from adjacent anchors are now tied together. By tying single strands of sutures from adjacent anchors together, a strong horizontal mattress suture line is created on the glenoid rim holding the capsule firmly down onto the bone. The knots are completed, thus completely obliterating the glenoid rim defect (Figure 15) and, if desired, shifting the inferior capsule proximally (or in a cephalad direction). If there is an available medial soft tissue flap of capsule and/or periosteum, this can be used to reinforce the repair. The range of external rotation is now checked gently to ensure that at least 45o of external rotation is available after the capsular reconstruction.

Figure 14a (left): A modest distal placement of the sutures in the capsule allows a slight proximal shift of the capsule during the repair, thus tightening the capsule. The capsule is fixed firmly to the anterior glenoid rim and reinforced, if possible, with a medial soft tissue flap (14b, right)

Figure 15: The knots are completed, thus completely obliterating the glenoid rim defect and shifting the inferior capsule proximally

Figure 16: After the repair is completed the arm should be able to be positioned without excessive tension in 45^o of external rotation

Closure

The subscapularis tendon is carefully repaired without over-lapping its edges using No. 1 Vicryl matress sutures. The deltopectoral interval is closed with 2 or 3 lightly applied No. 1 Vicryl and finally interrupted fat stitches may be inserted. We place an epidural catheter in the subacromial space for post-operative analgesia with 0.25% bupivacaine. The skin is closed with a subcuticular No 2-0 Prolene suture.

POST-OPERATIVE REHABILITATION

A Polysling is used and the patient retains this for two weeks after surgery. The patient then commences light active exercises for four weeks. The sling may be used intermittently but is discarded at 6 weeks. At 8 to 10 weeks the patient often can return to light low risk activities, such as swimming and jogging. At three months, the patient returns to training and at four months to full scale contact sports provided he or she has regained strength and, most importantly, control and confidence.6 (See the Website of the Nottingham Shoulder and Elbow Unit at www.NSEU.org.uk). Hospital physiotherapy is prescribed rarely and only under circumstances of delayed rehabilitation or shoulder stiffness, and is not commenced before 10 weeks.

COMPLICATIONS

Peri-operative

• Axillary nerve damage at operation
• Poor placement of anchor sutures

Early (within 6 weeks)

• Wound infection
• Subscapularis repair rupture
• Avulsion of capsular repair

Late (between 6 weeks and 6 months)

• Shoulder stiffness
• Recurrence of instability
• Failure of the subscapularis repair giving rotator cuff deficiency weakness and apprehension
• Failure of the anchor sutures

FURTHER READING

• McAuliffe TB, Pangayatselvan T, Bayley, I. Failed surgery for recurrent anterior dislocation of the shoulder. Causes and management. J Bone Joint Surg [Br] 1988; 70(5): 798-801
• Neumann L, Wallace WA Chapter 19: Open Repair of Instability. In: Shoulder Surgery, ed: S. Copeland). WB Saunders, London 1997: 188-208

REFERENCES

1. Hovelius L, Lind B, Thorling J. Primary dislocation of the shoulder. Factors affecting the two-year prognosis. Clin Orthop 1983; 176: 181-5
2. Simonet WT, Cofield RH. Prognosis in anterior shoulder dislocation. Am J Sports Med 1984; 12(1):19-24
3. Rowe CR, Patel D, Southmayd WW. The Bankart procedure: a long-term end-result study. J Bone Joint Surg [Am] 1978; 60(1): 1-16
4. Bankart ASB. Recurrent or habitual dislocation of the shoulder-joint. Br Med J 1923; 2: 1132-3 5 Perthes G. Uber operationen bei habitueller schulterluxation. Deutsch Ztschr Chir 1906; 85: 199-227
5. McDermott DM, Neumann L, Frostick SP, Wallace WA. Early results of Bankart repair with a patient-controlled rehabilitation program. J Shoulder Elbow Surg 1999; 8(2): 146-50

Copyright date: 2nd July 1999

Correspondence: Professor W Angus Wallace, Nottingham Shoulder and Elbow unit, City Hospital, Nottingham NG5 1PB , UK (Email: Angus.Wallace@rcsed.ac.uk)

©1999 The Royal College of Surgeons of Edinburgh, J.R.Coll.Surg.Edinb., 44; 4: 245-50