Labral Abnormalities

Patients who have undergone labral repair generally fall into two categories: those who have had SLAP repairs for an athletic-type injury or trauma of some sort, and those who have undergone Bankart repairs for shoulder dislocation.

Surgical Considerations

Snyder and associates [36] coined the term SLAP lesion in 1990. Snyder and others attempted to classify SLAP lesions [37,38]. In assessing a SLAP lesion, the surgeon must have a thorough understanding of the normal anatomy and the normal variants commonly seen in the superior labrum and biceps insertion region. Without such an understanding, aberrant but nonpathologic anatomy may be mistake for a SLAP lesion [39,40].

After the diagnostic portion of the arthroscopy is performed, any degenerative labral tissue is debrided. The bony surface of the superior glenoid is abraded in preparation for the repair. The biceps anchor is repaired with either bioabsorbable tacks or bioabsorbable or metallic suture anchors. Of 102 patients who have type II SLAP lesions treated with suture anchor techniques, Burkhart and colleagues [41] report 97% excellent or good results. This group included 44 baseball pitchers, 37 of whom were able to return to preinjury level of activity.

Reported complications of SLAP repair include penetration of titanium screws used for biceps anchor fixation device into the glenoid articular cartilage, loosening of a screw used for fixation, loose bioabsorbable tack material in the joint necessitating arthroscopic removal, adhesive capsulitis, and failed repair [42-44].

During a diagnostic arthroscopy in a patient who has anterior instability, the extent of the lesion is defined. Many types of lesions have been described with variable involvement of the following structures: labrum, glenoid rim, capsule, inferior glenohumeral ligament (IGHL), or middle glenohumeral ligament. The IGHL may be avulsed from the humerus, a so-called ''HAGL'' lesion. Chondral defects may be present (glenoid labrum articular disruption). In chronic cases, the labrum tends to scar ectopically beneath the glenoid rim to the scapular neck.

Surgery most commonly is performed arthroscopically. The ectopically scarred tissue of the anterior labral ligament complex (LLC) is released and mobilized. This mobilization stops once the release reaches the 6:00 position (relative to the glenoid), but should be extended in the case of atraumatic instability. Next, the anterior portion of the scapular neck is decorticated to prepare the attachment site for the repaired LLC.

Bioabsorbable anchors are gaining favor over metal anchors because of the danger of implant dislocation or misplacement with resultant arthritis. The first anchor is placed into the 5:00 to 5:30 position of the glenoid. Anchors that are too superficial create chondral injury to the humeral head, whereas those pushed in too deep may suffer suture abrasions. Anchors placed too shallow with reference to the glenoid rim may penetrate the glenoid's subchondral bone and cause anchor arthritis.

An anchor suture is passed through the IGHL and labrum at the most inferior position, about 1 cm lateral to the glenoid rim. Depending on the size of the lesion, three to four suture anchors are used. The ligament shift occurs in an infer-osuperior and lateromedial direction. The magnitude of the shift depends on the anterior laxity and tissue redundancy. If warranted, a concomitant posterior capsular plication, SLAP repair, or rotator interval closure may be performed.

Most patients who have multidirectional instability are well managed with a rigorous physician-directed home exercise program [45]. There are many soft tissue and bony procedures available, however, that are designed to stabilize the glenohumeral joint for cases that have failed at least 6 months of conservative treatment. To be a candidate for soft tissue surgery, glenoid hypoplasia or aplasia must be ruled out as a cause of the clinical shoulder instability.

Many capsular plication surgeries have been described. The Putti-Platt procedure involves dissection of the subscapularis tendon 2.5 cm from its insertion. The scapular neck is roughened to create a bed onto which the lateral stump will adhere. The lateral stump of the tendon is then tensioned and attached to the anterior capsular and labral complex. The medial stump is then lapped over the lateral stump, shortening the capsule and subscapularis muscle. Recurrent instability and loss of motion are common after this procedure. In a review of 101 patients, Fredriksson and colleagues [46] report a 20% recurrent instability rate, and all patients had a decrease in range of motion.

In 1980, Neer and Foster [47] described the classic inferior capsular shift, which they performed on 32 patients who had multidirectional instability. These authors emphasized capsular detachment from the humeral neck by using a T-shaped incision with the stem of the T aimed at the glenoid and in between the middle and inferior glenohumeral ligaments. The top of the T is parallel to the humeral anatomic neck 1 cm from the capsule's lateral insertion. The inferomedial flap is mobilized first, tensioned, and attached by suture to the remnant lateral capsule or adjacent subscapularis stump. The superomedial flap is advanced distally and sutured to the superior and anterior lateral capsule remnant and subscapular stump. This procedure reduces capsular redundancy and obliterates the axillary pouch. This procedure has been modified many times. Currently, it is more common to make the shift on the glenoid side.

The Eden-Hybbinette procedure uses a bone block, typically an iliac graft, to extend the anterior glenoid and theoretically impart stability. There are many variations regarding the graft shape, placement technique, and type of fixation for this procedure. In 41 cases, Paavolainen [48] reported 3 with recurrent instability, an average loss of 10% of external rotation, and 10% development of degenerative joint disease.

The use of arthroscopy for multidirectional instability is evolving. Thermal or radiofrequency capsular shrinkage has been used. High failure rates, worrisome case reports of articular cartilage and nerve damage, and concerns about the effect of these modalities on the tissue have limited the attractiveness of these procedures to many surgeons [49]. Arthroscopic suture capsule plication has been reported with promising results, but remains a technically difficult procedure.

Anterior instability with injury to the anterior inferior labrum, adjacent capsule, and anterior band of the inferior glenohumeral ligament accounts for 95% of glenohumeral instability and typically is because of trauma [1,6]. Atraumatic instability has a higher likelihood of being multidirectional and can be because of inherent laxity of the joint capsule [1]. There are more than 100 procedures reported for treatment of instability and they can be divided into anatomic or nonanatomic repair [1,3,6].

Anatomic repairs involve direct reattachment of the labrum and adjacent capsular structures to the anterior inferior glenoid as in the classic Bankart repair [1,2]. The Bankart repair involves removal and stabilization of the anterior capsulolabral structures by way of the deltopectoral interval [2,6,15]. Osseous drill holes are placed in the anterior inferior glenoid at the junction of the labrum and articular cartilage in the 3:00, 4:00, and 5:00 positions. The sutures are then attached to the labrum and anterior band of the inferior glenohumeral ligament that make up the capsulolabral complex [2,6]. The use of suture anchors has helped make arthroscopic Bankart repairs more widespread [2]. Suture anchors are placed along the articular margin of the anterior inferior glenoid rim through the subscapularis and the sutures on the anchors are tied to the capsulolabral complex [2,15]. These suture anchors can be made of titanium or bioabsorbable material, such as polylactic acid [5,6,50]. Bioab-sorbable tacks or staples also can be used [6]. Glenoid fractures associated with instability and involving more than 25% of the glenoid surface are repaired by an open procedure with screw fixation. Occasionally bone graft is necessary if there is significant bone loss [1,6].

Nonanatomic procedures can involve manipulation of either soft tissue or bone block structures. Putti-Platt and Magnusson-Stack procedures involve indirect tightening of the anterior capsule by way of shortening and manipulation of the subscapularis [3,12]. Bone block procedures include the Bristow-Helfet and Eden-Hybinette procedures, in which the coracoid is resected and reat-tached to the anterior inferior glenoid [1,3,12]. A bone block acts as a mechanical stabilizer of the shoulder and prevents recurrent anterior subluxation. Nonanatomic repairs have lost favor amongst surgeons because of persistent pain and other complications; however, knowledge of these procedures and variations of them are important because these patients can present for MR imaging and the anatomy can be distorted [3].

Procedures for shoulder instability can be performed in combination with a capsulorraphy, which can be performed by way of direct suture technique or laser or thermal capsular shrinkage [1,3,6]. In the inferior capsular shift procedure, a horizontal T-shaped incision is made in the anterior capsule [3]. The inferior portion is shifted superiorly and the superior portion is advanced ante-roinferiorly with the overlapping tissues sutured over each other. This overlap thickens the anterior inferior capsule and creates greater tension on the humeral side [3]. Laser and thermal-assisted capsular shift also can be performed; however, results are controversial [3,51,52].

MR Findings

Following repair of the anterior capsulolabral complex, there should be anatomic position and morphology of the labrum and capsule without fluid or

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Responses

  • May
    Is bicep pain after a laparoscopic slap repair normal?
    7 years ago
  • fosco burrowes
    What is an labral Abnormality?
    6 years ago

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