Background
In the Bristow procedure and its variants, the coracoid process is transferred through the subscapularis tendon as a method of treating recurrent anterior instability of the shoulder. The coracoid tip is transferred to the anteroinferior glenoid neck and likely serves as a bone block in front of the humeral head. The transferred short head of the biceps and coracobrachialis are placed so as to produce a strong dynamic buttress across the anterior and inferior aspects of the joint when the shoulder is in the vulnerable abducted and externally rotated position. [1]
Helfet first described the Bristow procedure in 1958 and named it after his late mentor. He described a procedure in which the terminal 1 cm of the coracoid and the conjoined tendon were transferred through a horizontal slit in the subscapularis onto the neck of the scapula. The transfer was held in place by sutures through the conjoined tendon and subscapularis.
Latarjet described a similar procedure in 1954, in which he transferred the tip of the coracoid along with the conjoined tendon through a horizontal slit in the subscapularis and fixed it with a screw. Many other surgeons have described variations of the procedure; however, the common aspect of most current techniques is fixation of the transferred coracoid to the scapular neck with a screw.
Boileau et al found bony glenoid lesions in 49% of their patients with recurrent instability. [2] Loss of glenoid bone can disrupt the glenoid concavity, thereby reducing the effectiveness of the concavity-compression mechanism in stabilizing the shoulder against anterior translation. [3] Therefore, patients with recurrent anterior instability and glenoid bone loss may not achieve favorable outcomes with soft-tissue procedures alone. Soft-tissue procedures do not restore the firm glenoid socket that normally resists anterior translation.
Patients are likely to suffer bony involvement at the time of initial dislocation. In the case of acute recurrent instability, identifiable fracture fragments are frequently reported. [4] In contrast to acute recurrent instability, patients studied at a mean of 15 months after initial dislocation exhibited erosive bone loss without an identifiable fracture fragment. [5] This pattern of bone loss demonstrates a progressive loss of bone over time.
Indications
Indications for open surgical intervention include recurrent anterior shoulder instability after failure of a course of nonsurgical management. [6] If glenoid bone loss is judged to be greater than 25-30%, restoration of bone loss must be considered as an option in order to prevent recurrent instability. [7]
If a bony fragment is available, open or arthroscopic stabilization with bone fragment reduction and fixation might be performed. However, if no bony fragment is available, glenoid augmentation becomes a viable option. This can be done with bone graft augmentation or with coracoid transfer augmentation, such as the Bristow procedure. [8]
Contraindications
Coracoid transfer augmentation for bony glenoid defects is less likely to be successful in patients who have the following:
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Uncontrolled epilepsy
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Instability associated with paresis of the deltoid, rotator cuff, and/or periscapular musculature
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Multidirectional instability associated with generalized ligament laxity
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Voluntary instability
Continued nonoperative management should also be considered in patients who are medically unfit for surgery, elderly patients, and low-demand patients. [3]
Outcomes
In a retrospective study of the modified Bristow technique for anterior shoulder instability, nearly 70% of 52 shoulders in 49 Naval Academy midshipmen achieved a good-to-excellent outcome. [9] The mean follow-up was 26.4 years; this was the longest outcome study of this technique in the literature. Recurrent dislocations were seen in 9.6% in this series, and recurrent subluxations were subjectively described in 5.8%. The reported incidence of recurrent instability following the Bristow procedure is in the range of 0-14%.
Torg et al reported the outcomes of the modified Bristow procedure in 207 patients (212 shoulders) at an average follow-up of 3.9 years. [10] They found a 3.8% redislocation rate and a subjective subluxation rate of 4.7%. A high percentage (96.2%) of the patients were happy with the procedure and noted that they would have the surgery again.
Hovelius et al reported on 112 shoulders with recurrent anterior dislocation treated with the modified Bristow technique at a mean follow-up of 30 months. [11] The incidence of redislocation was 6%, with a 7% subluxation rate.
After evaluating the May modification of the Bristow-Latarjet procedure in 319 shoulders, Hovelius et al concluded that the procedure yields good results, with bony fusion of the coracoid in 83% of cases. [12]
In a study of 38 rugby players (40 shoulders) in whom traumatic anterior instability of the shoulder was treated with arthroscopic Bankart repair followed by a Bristow procedure with preservation of the repaired capsular ligaments, Tasaki et al found that the combined surgical procedure effectively prevented recurrent dislocation, though some of the players complained of insufficiency in the quality of their play. [13]
In a study of 59 consecutive patients with recurrent anterior instability after a failed arthroscopic Bankart repair who then underwent a Bristow-Latarjet procedure via either an open (n = 25) or an arthroscopic approach (n = 34), Clowez et al found that this revision procedure (open or arthroscopic) efficiently restored shoulder stability and allowed a return to sport. [14] Patients with a large and deep Hill-Sachs lesion had more persistent anterior apprehension and a lower sports level.
Schmidt et al (N = 7519) compared 30-day outcomes (length of stay, short-term complications, hospital readmission, all-cause reoperation, and death) after arthroscopic Bankart repair (n = 6990) with those after the Bristow-Latarjet procedure (n = 529). [15] Although both procedures were associated with low overall complication rates, the Bristow-Latarjet procedure was associated with a significant higher rate of short-term reoperation or revision stabilization.
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The coracoid process (C) and the conjoined tendon (CT) after osteotomy.
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The glenoid (G), humeral head (H), and the scapular neck (N) after division of the subscapularis and capsule.
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The musculocutaneous nerve (M) is identified near the conjoined tendon (CT) in order to ensure it is not under undue tension.
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The coracoid tip has been secured to the scapular neck, and the capsule and subscapularis have been repaired.