Download Modified Bristow-Helfet anterior Stabilization

Modified Bristow-Helfet anterior Stabilization (Former Latarjet)
The Bristow procedure involves the transfer of the distal portion of the coracoid process with the
attached conjoined tendon to the anterior aspect of the scapula neck through a transverse opening in
the subscapularis muscle. The procedure was described by Helfet and is commonly known as the
Bristow procedure,5 but in fact, a similar procedure was described by Latar jet four years earlier in
1954 and hence is also known as the Latarjet procedure.6 The operation is thought to work in
several different ways: (1) as an anterior bone block; (2) in abduction external rotation, that is, the
position of instability, the restraining bow string keeps the head from sublux-ing anteriorly; (3) the
subscapularis is prevented from rolling superiorly, and the lower third of the subscapularis is pinned
down as a tenodesis.
Indications
The Bristow-Helfet procedure is very useful for the recurrent anterior instability of the traumatic
type that previous surgery has failed to correct and scarring is such that a more sophisticated
procedure is difficult to perform. In the presence of any element of anterior glenoid insufficiency,
the bone block effect of this procedure can be useful.
Contraindications
The Bristow-Helfet procedure should not be used in throwing athletes because they cannot return to
preinjury status. Anatomy is altered, and there is relative shortening of subscapularis muscle and
therefore loss of internal rotation power. If this procedure fails, then reconstruction can be difficult
because of the altered anatomy and intense scarring that this procedure can produce. This operation
is not indicated for multidirectional instability or in patients whose anterior instability is reproduced
with the arm at the side.
Preoperative Investigation
Routine examination under anaesthesia before stabilization and arthroscopy can confirm the intraarticular pathology and in particular the state of the anterior glenoid.
Position of Patient
The standard beach chair position is used with a sand bag under the medial border of the scapula to
thrust the shoulder forward.
Technique
An anteroinferior approach is used as in the previous two sections.
The deltopectoral interval is found and separated by blunt dissection, preserving the cephalic vein.
The coracoid process is then identified, the coracoid lever retractor (Copeland) is inserted to retract
the superior wound edge, and the conjoined tendon is identified. The conjoined tendon should be
isolated medially and laterally. Usually, a small strand of muscle lateral to the short head of biceps
marks the lateral extent of the conjoined tendon. This step is necessary to allow the distal reflection
of the coracoid process and conjoined tendon as one unit to permit adequate visualization of the
underlying subscapularis muscle. The fascia overlying the superior aspect of the coracoid process is
reflected 1 to 1.5 cm from its tip. This helps to delineate the area of the coracoid process that will be
osteotomized and reflected with the attached conjoined tendon.
It is easier to drill the coracoid at this stage before osteotomy. An AO malleolar screw is used for
fixation (Fig. 8-16). The coracoid process is osteotomized 1 cm at proximal to the tip. The coracoid
is palpated, and the osteotomy is made with a power saw at right angles to the coracoid itself to
avoid leaving an oblique surface. If a small spike of bone remains on the coracoid process, it should
be removed with the use of a rongeur to leave a completely flat and smooth surface to permit proper
contact with the anterior surface of the glenoid neck when the transfer is complete.
The coracoid process and conjoined tendon are reflected distally to permit visualization of the
underlying subscapularis and subscapularis tendon and muscle. Distal traction should not be applied
to the coracoid, because this can inadvertently place traction on the musculocutaneous nerve, which
can enter the conjoined tendon 2 to 8 cm distal to the coracoid process (Fig. 8-17). Once the
coracoid process and tendon are reflected distally, they should be placed within the depth of the
wound.
The upper and lower limits of the subscapularis muscle are identified by palpation. The lower
border of the subscapularis is identified by the circumflex humeral veins. The upper border of
subscapularis is easily identified at the rotator interval. The subscapularis muscle is split in line with
its fibers from lateral to medial at the junction of the middle to lower third of the muscle. While
doing this maneuver, the surgeon should palpate the anterior lip of the glenoid. To do this, the arm
needs to be repeatedly internally rotated because external rotation can induce some degree of
anterior subluxation of the humeral head, making the glenoid rim difficult to palpate.
The joint is then entered by sharp dissection onto the anterior face of the glenoid neck, where a
Bankart lesion may well be present (Fig. 8-18). The labrum and capsule on the anterior surface of
the glenoid and scapula neck are incised and reflected superiorly and inferiorly. The glenoid neck is
now exposed using a Rowe pronged retractor or devil's pitchfork; this step must be done under
direct vision. A 3.2-mm hole is drilled in the anterior-to-posterior direction of the glenoid neck,
parallel but 1 cm medial to the articular surface (Fig. 8-19). Good visualization of the articular
surface of the glenoid is achieved by posterior subluxation of the humeral head with a Bankart
retractor. The drill must pass through both cortices of the glenoid neck and depth gauge used to
measure the length of the hole. This measurement is then added to the depth of the coracoid
fragment, and the appropriate length screw is selected.
Care must be taken not to allow the screw to protrude posteriorly, and hence the screw size below
the combined lengths is used. Any posterior protrusion of the screw can cause posterior scapula
discomfort. The screw is passed through the coracoid fragment such that the fragment is on the
smooth part of the shank of the screw. The threaded part of the screw is then aimed into the hole in
the glenoid neck, and the coracoid fragment is screwed down so that there is cancellous apposition
between the Bankart defect and the bony fragment (Fig. 8-20). Once the screw is in place and the
bone block fixed, the surgeon should check that there is no overhang of bone over the glenoid rim.
If there is, then the screw should be loosened and the bone block rotated so that the narrowest
portion of the bone block lies lateral to the screw. The fascia overlying subscapularis muscle should
be reapproximated with two absorbable sutures, and the 'wound then should be closed in layers
(Fig. 8-21).
Postoperative Management
A sling is used for 3 'weeks with a body belt; elbow and hand motions are begun on the first day;
pendulum exercises at 3 weeks; and formal range of motion and strengthening exercises only started
at 6 weeks. Noncontact sports are permitted at 3 to 4 months, but contact sports at 6 months. A
postoperative radiograph should be taken to ensure proper placement of bone block and screw
before the patient is allowed to return to full activities.
Complications
The most common complication described is migration of the bone block and/or migration of the
screw. If at the time of surgery the bone block is split when tightening the screw, some other form
of fixation must be used, that is, staple or suture fixation alone. Damage to the musculocutaneous
nerve by overvigorous distal traction on the separated coracoid is a complication but usually only
causes a transient palsy. Proper placement of the bone block and screw is in the middle-to-lower
equatorial position of the anterior surface of the scapula neck and within 5 mm of the articular
surface of the glenoid. One of the largest series reported is that by Hovelieus et al. in 1983 with a
redislocation rate of 6 percent in 112 cases after a 30-month follow-up.7 The best results were in
those patients in whom the bone block was placed on the inferior half of the glenoid rim within 1
cm of the glenoid surface.
References
1. Neer CA, Fithian TE, Hansen PE et al. Re-inforced capsular cruciate repair for recurrent anterior
dislocation of shoulder. Orthop Trans 9:44, 1984
2. Turkel SJ, Panio MW, Marshall JL, Girgis FG: Stabilising mechanism preventing anterior
dislocation of the gleno-humeral joint. J Bone Joint Surg [Am] 63:1208—17, 1981
3. O'Brien SJ, Neves MS, Rozback RS et al: The anatomy and histology of the inferior glenohumeral ligament complex of the shoulder. Paper presented at the Annual meeting of the Shoulder
and Elbow Society, February 1989, Las Vegas.
4. Cofield RH, Nessler JP, Weinstabl R: Diagnosis of shoulder instability by examination under
anaesthesia. Clin Orthop Rel Res 291:45-53, 1993
5. Helfet AJ: Coracoid transplantation for recurring dislocation of the shoulder. J Bone Joint Surg
[Br] 40:198-202, 1958
6. Hovehus L et al: The Bristow-Latarjet procedure for recurrent dislocation of the shoulder. A twofive year follow up study on the results of 112 cases. Acta Orthop Scand 54:284-90, 1983
Suggested Reading
Ribbans WJ, Mitchell R, Taylor GJ. Computerised arthrotomography of primary anterior
dislocation of shoulder. J Bone Joint Surg [Br] 72:181-6, 1990