Injuries of the superior aspect of the glenohumeral labrum can be challenging to diagnose and manage. Little attention was paid to these lesions prior to the widespread use of shoulder arthroscopy. In recent years it has become clear that some symptomatic superior labral detachments can be treated effectively with arthroscopic repair.1-5 In this paper we describe our operative technique.

Background

           Andrews and colleagues described detachment of the superior labrum in a subset of throwing athletes in 1985.6 Snyder and co-workers introduced the term SLAP lesion - indicating detachment of the superior labrum extending from anterior to posterior.7 They classified SLAP lesions into four distinct types based on the morphology of the tear, emphasizing that this lesion also disrupts the origin of the long head of the biceps.7 (Figure 1) Maffet and colleagues described three additional patterns.8 (Figure 2)

          The prevalence of SLAP lesions is disputed. Some surgeons have encountered SLAP lesions in as many as 12% of shoulders undergoing shoulder arthroscopy. Others have seen these lesions in less than 2% of patients.7-9

           The origin of SLAP lesions is uncertain, but two injury mechanisms have been suggested: 1) a crushing injury of the labrum between the humeral head and glenoid which occurs as the abducted arm is subjected to an axial load; or 2) a repetitive or acute distraction injury to the biceps-labral complex. Up to 40% of patients with SLAP lesions have associated anterior labral injuries (Bankart lesion) and glenohumeral instability.8, 10 Nearly half have rotator cuff pathology.8, 10
Normal biceps function and glenohumeral stability is dependent on a stable superior labrum and biceps anchor. Pagnani and co-workers found that a complete lesion of the superior portion of the labrum large enough to destabilize the insertion of the biceps was associated with significant increases in anterior-posterior and superior-inferior glenohumeral translation.2

Evaluation

           A comprehensive history should define overhead sports and injuries. A patient with a superior labral injury may have non-specific complaints. Pain is most frequently associated with overhead activity. Some patients have mechanical symptoms of painful clicking or catching of the shoulder.6 Useful examination maneuvers include the joint compression-rotation test7, the crank test11, and OÕBrienÕs test12 although none of these is specific to SLAP lesions. The reliability of MRI and MR arthrography for the diagnosis of SLAP lesions is disputed13,14 and definitive diagnosis usually requires arthroscopy.

          It is important to distinguish an injury of the superior labrum from a normal anatomic variant. Some individuals have a meniscoid appearance of the superior labrum which resemble a SLAP lesion.15 Around 10% of patients have an anterior-superior sub-labral foramen that separates the labrum from the glenoid rim.16 The Buford complex is an anatomic variant observed in approximately 1.5% of patients in which a stout middle glenohumeral ligament attaches just anterior to the biceps anchor without transitional labral tissue.17 Since most superior labral injuries are type II SLAP lesions, they can be distinguished from normal anatomic variants by verifying that the entire biceps superior labral complex is loose when lifted upwards with a probe. (Figure 3B)

Management

          A type 1 SLAP lesion may represent age related fraying of the superior labrum and does not require specific treatment. Arthroscopic debridement of labral fraying does not reliably relieve symptoms long term.18, 19 Type III lesions should be excised and debrided to a stable rim, much like a white on white bucket handle meniscus tear in the knee. The exception to this is a type III lesion involving a Buford complex which should be treated as a type II SLAP lesion.20 Type II and IV SLAP lesions should be repaired. A type IV lesion requires a side to side repair of the biceps tendon, in addition to reattachment of the superior labrum. In practice, most type IV lesions have such an altered biceps origin that biceps tenodesis is more practical. In addition to the treatment of the SLAP lesion, associated rotator cuff pathology or instability should be independently evaluated and treated. Operative treatment of type II and IV lesions is associated with satisfactory results in over 80% of patients.1, 3-5, 21

Operative Technique

           We prefer the beach chair position for shoulder arthroscopy.22 Three portals are used to repair a SLAP lesion: posterior, anterior-superior, and lateral. The anterior-superior portal is placed one centimeter distal to the acromion and one centimeter lateral to the acromio-clavicular joint. Proper placement allows a disposable six to seven millimeter cannula to sweep freely over or under the biceps tendon and provides access to the biceps labral anchor. The lateral portal is placed midway between the antero-lateral and postero-lateral edge of the acromion. The rotator cuff is perforated with an 11 blade parallel to the rotator cuff fibers and a disposable cannula is inserted.

Preparation of the SLAP repair site
          The superior labrum is mobilized along the entire area of detachment using electrocautery and a 3.5 motorized shaver to take down any fibrous adhesions. This area usually extends from the 11 to the 1 oÕclock positions if the glenoid is considered as a clock face. The shaver is used to debride the superior glenoid rim until punctate bony bleeding is produced. (Figure 3C) The repair surface of the labrum is also gently debrided to stimulate a healing response. Throughout this preparation the surgeon should keep in mind that the suprascapular nerve lies an average of three centimeters medial to the glenoid rim and is vulnerable to injury.23

Insertion of Suture Anchors
          Two suture anchors are usually adequate to secure the biceps anchor and superior labrum. We prefer to use bioabsorbable suture anchors with number 2 braided non-absorbable suture. The suture anchors are positioned so that each one splits the difference between the biceps and the normal area of labral insertion, usually 11:30 and 12:30 on a clock face. Using the lateral portal, the suture anchors are placed at the junction of the articular cartilage and cortical bone (Figure 3D). The security of anchor fixation is tested with a firm pull on the sutures.

Suture Placement and Knot Tying
          Once the suture anchors are in place, one end of each suture is passed through the labrum. We use a set of curved, sharp, cannulated hooks inserted through the anterior-superior cannula to perforate and capture a substantial portion of labral tissue from a medial to lateral direction (Spectrum set, Linvotec, Largo, Florida). The surgeon may choose to incorporate some of the biceps tendon near the junction of the biceps and labrum if necessary to secure the biceps anchor.

          A shuttle relay (a stout wire that incorporates a loop for the passage of suture) is advanced into the joint through the cannulated hook until visible inside the joint. The portion of the shuttle relay inside the joint is then grasped with a suture retriever through the lateral portal. One end of the suture from the suture anchor is passed through the wire loop in the shuttle relay. As the other end of the suture relay is pulled out through the anterior-superior portal, the end of suture that was passed through the loop in the relay is pulled into the joint, through the glenoid labrum, and out the anterior-superior portal. Next, the other end of the suture is grasped in the joint and brought out through the anterior-superior portal. At this point, the suture passes through the labrum, and both ends exit the joint through the antero-superior cannula. Alternately pull each end of the suture to verify that they do not cross one another in the cannula and, that they slide freely. The procedure is then repeated for the suture through the second anchor.

          The knots are tied with the elbow and shoulder in flexion in an attempt to reduce the tension in the biceps labral complex. We prefer the Duncan Loop with six half hitch throws. Alternate the half hitch throws in pairs while alternating the post from one suture end to the other (Figure 3D). The reader is referred to the internet site www.shoulder.com for alternatives and instruction in arthroscopic knot tying.

          If there is an associated Bankart lesion, the same fundamental steps and technique are used to repair the Bankart lesion. Usually three suture anchors are required in a Bankart repair.

Postoperative Care

           Patients are protected in a sling for four weeks. They are allowed gentle motion at the elbow and wrist. The patient must avoid external rotation and extension of the shoulder. At six weeks the patient is allowed gentle progressive and protected biceps strengthening. No forceful use of the biceps or heavy lifting is allowed for four months. (Figure 3E) No overhead motion is allowed for six months.

Geoff Higgs, MD is Sports Medicine and Shoulder Fellow at Massachusetts General Hospital and Harvard University.

Jon J. P. Warner, MD is Chief of the Harvard Shoulder Service and Associate Professor of Orthopaedic Surgery at Harvard Medical School.

Address Correspondence to:
Jon J. P. Warner, MD; Massachusetts General Hospital; Professional Office Building Suite 403; 275 Cambridge Street; Boston, MA 02114
e-mail: jwarner@partners.org