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WORKUP
| Section 5 of 11  |
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Imaging Studies:
- On plain radiography of the shoulder, an anteroposterior view of the shoulder in internal and external rotation, outlet, and axillary views should be obtained. Findings are usually normal.
- Occasionally, a SLAP fracture, which represents a superior humeral head compression fracture, can be observed.
- Plain radiographs should be carefully reviewed for other potential pathology, such as an os acromiale, an anterior acromial spur, or a degenerative AC joint.
- Nonenhanced MRI has proven to be unreliable in determining the presence of SLAP tears. It is useful to evaluate potential concomitant pathology, such as partial thickness or full thickness rotator cuff tears. It is also valuable in detecting the presence of a paralabral cyst. Ganglion cysts encroaching on the spinoglenoid notch are associated with superior, usually posterior, labral tears.
- The use of contrast medium as in magnetic resonance arthrography offers improved visualization of intra-articular structures and is thought to improve the ability to accurately detect SLAP tears; however, reported results continue to be highly variable.
- Two useful signs on MRI are those of increased signal intensity in the posterior third of the superior labrum and a laterally curved intensity. The sublabral recess does not usually extend to the posterior third of the superior labrum, and therefore, high signal intensity between the labrum and the glenoid in this region is considered to be consistent with a superior labral tear. Another MRI finding considered to be highly suggestive of a superior labral tear is laterally curved signal intensity. On the contrary, a normal sublabral recess results in a medially curved area of signal intensity.
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TREATMENT
| Section 6 of 11  |
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Medical therapy: Initial treatment of suspected SLAP lesions should be nonoperative. Emphasis should be on rest, which means an initial period of no throwing. Capsular stretching, especially of the posteroinferior capsule, is important. Physical therapy focusing on rotator cuff and scapula stabilizer strengthening may be helpful. Surgical therapy: Initially, a complete diagnostic arthroscopy is performed. The rotator cuff should be carefully inspected for any partial thickness or full-thickness tears. The biceps anchor is inspected. Be aware of the potential normal variants as discussed earlier in this article (see Pathophysiology). Type III and type IV SLAP lesions are fairly obvious arthroscopically. The difficulty can sometimes come in differentiating a type I lesion from a type II as well as accurately diagnosing type II lesions and variants thereof.
Type I lesions are often associated with a meniscoid superior labrum where the lateral aspect is draped over the rim of the glenoid superiorly and the attachment is more peripheral. This particular morphology is more susceptible to developing degenerative tears, which is the pathology observed in type I lesions. Care must be taken not to assume that this meniscoid labrum represents a displaced type II lesion. A probe is placed under the superior labrum, and a firm attachment is demonstrated. In inspecting the superior labral attachment, the key factor to evaluate is if whether more than 5 mm of superior glenoid is exposed under the labrum. A superior sublabral recess is often observed and is a normal finding. However, if this recess is greater than 5 mm, the biceps anchor is highly likely to be unstable.
The superior labrum both anterior and posterior to the biceps root should be carefully probed. Placing the arm in approximately 70-90° of abduction and then progressively externally rotating the arm can demonstrate the peel-back sign, which is observed with type II posterior lesions as well as in combined anterior and posterior type II lesions. If more than 5 mm of the posterosuperior glenoid is uncovered or the biceps root at the level of the supraglenoid tubercle is uncovered with this maneuver, then the peel-back sign is positive and the superior labrum must be repaired. The peel-back sign is not usually observed with type II anterior SLAP lesions. A positive drive-through sign where the arthroscope can be easily passed from the superior aspect of the joint to the inferior recess without any manual distraction is observed with all 3 variants of type II SLAP lesions. This anterior pseudolaxity is usually resolved with repair of the SLAP lesion, and the drive-through sign is eliminated.
Surgical treatment of a type I lesion consists of debridement. Similarly, in a type III lesion, the bucket-handle tear of the meniscus can be debrided because the biceps anchor is intact. In a type II lesion, the biceps anchor is repaired back down to the superior labrum with suture anchors. In type IV lesions, if less than 30% of the tendon is involved and the biceps anchor is intact, then the involved labrum and tendon can be resected. If more than 30% involvement is noted in an older patient, a biceps tenodesis can be performed. In the younger more active individual, suture repair of the tendon, along with suture anchor repair of the labrum, should be performed.
Various techniques have been described to repair the superior labrum arthroscopically. These include the use of metal staples, metal screws, bioabsorbable tacks, and a transglenoid technique. Metal staples and screws require a second surgery for removal and are no longer used. Good results have been reported with the use of bioabsorbable tacks; however, concerns over potential particulate debris and foreign body reaction have led many surgeons to use suture anchors loaded with nonabsorbable suture. Preoperative details: General anesthesia supplemented with an interscalene block is the preferred anesthetic technique. An examination with the patient under anesthesia is conducted to assess for any capsular contracture or instability. The patient is placed in the beach-chair position. Intraoperative details: A standard posterior viewing portal is made. An anteroinferior portal is made just above the subscapularis tendon using an outside-in spinal needle localization technique. Similarly, an anterosuperior portal is made. The incision for this portal is just off the anterolateral corner of the acromion and enters the joint through the rotator interval laterally. Importantly, place these portals in a parallel fashion; spinal needle localization can aid in achieving this prior to incision for the portals. Cannulas are placed in both portals. The area of labral detachment is debrided, initially with a soft tissue resector, and the bone is then lightly dusted with a burr.
The instrumentation for anchor placement can then be introduced either though the cannula in the anterosuperior portal or percutaneously through the musculotendinous junction of the supraspinatus. The authors prefer percutaneous placement of the anchors. A bioabsorbable anchor loaded with 2 nonabsorbable sutures is then placed.
The number of suture anchors used depends on the extent of the tear. Initially, the more posterior limb of one suture pair is then retrieved into and out of the anteroinferior cannula. A variety of techniques exist to pass this suture through the labrum. The authors prefer to initially pass a looped 2-0 Prolene suture through the labrum using a curved suture passer. The 2 free ends of the Prolene suture are retrieved out of the anterosuperior cannula. The looped end of the suture, which now resides in the anteroinferior cannula, is used to shuttle the limb of the anchor suture through the labrum. An arthroscopic knot is tied after both limbs of the anchor suture have been retrieved into the anterosuperior cannula.
The second suture is then passed through the labrum in a similar fashion, and an arthroscopic knot is tied. At this time, the need for additional anchors is assessed and they are placed as necessary.
Ensure that the posterosuperior labrum is adequately stabilized in order to neutralize the peel-back forces. In introducing a posterosuperior anchor, using a posterolateral portal is usually necessary because the posterosuperior glenoid has a steep angle that makes instrumentation from the more anterior portal difficult. This posterolateral portal can be made without a cannula by passing the sheath for the anchor instruments directly through the rotator cuff at the musculotendinous junction. Postoperative details: The patient is kept in a sling for 3 weeks. Codman is initiated week 2. Passive range of motion exercises, including elevation and external rotation by the side, are also initiated week 2. No external rotation in abduction is allowed for the first 3 weeks because of the peel-back mechanism. Range-of-motion exercises, including passive posterior capsule and internal rotation stretching, are progressed during weeks 3-6.
At 6 weeks, progressive strengthening of the rotator cuff, scapula stabilizers, biceps, and the deltoid is initiated. Throwing athletes are allowed to begin an interval throwing program at 4 months. At 6 months, throwing from a mound is allowed. Pitchers may resume throwing at full velocity at 7 months postoperatively. Throughout the rehabilitation, as well as after, the patient should continue stretching the posteroinferior capsule daily. A recurrence of the capsular contracture can once again put the shoulder at risk for developing a SLAP lesion.
For nonathletes, the initial 4 months of rehabilitation is identical to that of throwers. At the 4-month mark, they can usually resume full activities.
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COMPLICATIONS
| Section 7 of 11  |
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Neurologic injury is the most common complication reported after arthroscopic shoulder surgery. These complications can be minimized by careful attention to patient positioning as well as a thorough knowledge of the neurovascular anatomy of the shoulder. When placing the patient in the beach-chair position, ensure that the head and neck are in a neutral position. Either hyperflexion or hyperextension could potentially lead to a neurologic injury.
When making the Neviaser portal, care must be taken to avoid too acute an angle or placing the portal too medial in order to avoid injury to the suprascapular nerve. When placing the suture anchors, ensure that the anchors are well seated below subchondral bone. If the anchors are too prominent, they may cause a chondral injury. The sutures should be tugged on to ensure that the anchors are well seated. Anchor migration, apart from compromising the repair, can result in significant chondral injury.
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OUTCOME AND PROGNOSIS
| Section 8 of 11  |
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In general, good results have been reported with arthroscopic SLAP repairs. In 1998, Morgan et al reported on their results in 102 patients. About 83% of their patients had excellent results, and 14% had good results. All pitchers returned to pitching, 84% at preinjury level.
In 1995, Pagnani et al reported that 12 of 13 overhead athletes were able to return to full preinjury level of activity after an arthroscopic SLAP repair. In 1993, Field and Savoie, as well as Burkhart in 2001 reported similar findings. In Field and Savoie's study, all of the athletes were able to return to sports activities without limitation.
In a 1999 report, Kim et al evaluated their results in 34 individuals who underwent arthroscopic suture anchor repair of an isolated SLAP tear. Approximately 94% had a satisfactory result as determined by using the University of California Los Angeles (UCLA) shoulder score. Thirty-one (91%) of the patients regained their preinjury level of function. However, they did note poorer outcomes in overhead athletes as compared with those not participating in overhead athletic activities.
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FUTURE AND CONTROVERSIES
| Section 9 of 11  |
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The etiology of shoulder pain and dysfunction, the dead arm syndrome, in throwing athletes is somewhat controversial. In 1991, Frank Jobe et al proposed that repetitive throwing stretches out the anterior capsuloligamentous structures, allowing anterosuperior migration during throwing with resultant subacromial impingement. They advocated open anterior capsulolabral reconstruction and reported a 50% return to pitching in 12 pitchers.
Christopher Jobe in 1995 and Gilles Walch in 1992 both described the concept of internal impingement. This refers to a spectrum of injury that involves the rotator cuff, posterosuperior labrum, and even bone. Similar to Frank Jobe's concept, the underlying pathology was thought to be stretching out of the anterior capsuloligamentous structures. In a normal shoulder, tightening of the anterior capsule such as occurs when the arm is placed in the abducted and externally rotated position results in obligate posterior translation of the humeral head. In the situation with lax anterior capsuloligamentous structures, this obligate posterior translation was postulated to not occur, leading to abnormal contact between the rotator cuff and posterior labrum because the head does not clear posteriorly. Anterior capsulolabral reconstruction was advocated as treatment. Results of this treatment have been mixed, with approximately 50% return to throwing.
In a 2001 article, Burkhart and Morgan have instead advocated type II SLAP lesions as the underlying cause of the dead arm syndrome. In a group of 53 throwing athletes, they reported a success rate of 87% in returning the patients to their preinjury activity level after arthroscopic SLAP repair.
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PICTURES
| Section 10 of 11  |
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| Caption: Picture 1. Superior labrum anterior and posterior (SLAP) lesion types.
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| Caption: Picture 2. Area of labral detachment is debrided to expose a bony bed. The awl for the anchor is introduced through the anterosuperior portal
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| Caption: Picture 3. Bioabsorbable anchor double-loaded with nonabsorbable number 2 suture is then implanted
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| Caption: Picture 4. One limb of each suture is passed through the labrum. Various suture passing techniques can be used to accomplish this.
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| Caption: Picture 5. In a 1-anchor repair, 1 suture can passed through the labrum posterior to the biceps and the other anterior to the biceps and tied down. Multiple anchors should be used if necessary.
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Picture Type: Image |
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BIBLIOGRAPHY
| Section 11 of 11 |
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Superior Labral Lesions excerpt |