SLAP Lesions (Superior Labrum Anterior to Posterior Tears)

Definition

Superior Labrum Anterior to Posterior tears, more commonly referred to as “SLAP” tears of the shoulder, are injuries affecting the superior glenoid labrum within the glenohumeral or shoulder joint and are due to anterior to posterior detachment of the superior labrum.

Anatomy

The shoulder joint is formed by the articulation between the humeral head and the shallow glenoid of the scapula, or shoulder blade. The glenoid labrum is a fibrocartilaginous ring of tissue that forms a peripheral lining of the bony glenoid socket of the shoulder. It functions to increases the overall surface area of the shallow glenoid, deepen the shoulder “socket”, and stabilize the humeral head, making it more difficult to dislocate the humeral head. Think of the labrum as a soft tissue “bumper” lining the glenoid rim. When the humeral head tries to dislocate, the labrum functions to keep the humeral head centered on the glenoid and prevent it from dislocating. Without the labrum, the shoulder joint would be intrinsically unstable and very easy to dislocate (See: Bankart tears of the labrum). The labrum derives its blood supply from the suprascapular, circumflex scapular, and posterior humeral circumflex arteries of the shoulder. However, the anterior, anterosuperior, and superior aspects of the labrum tend to have decreased vascularity (this is important as it relates to the intrinsic ability to heal SLAP tears. Poor blood supply is a poor prognosticator for the natural history of SLAP tears ie. They don’t usually heal on their own!). Furthermore, the superior labrum is particularly important because this is where the long head of the biceps tendon attaches to the glenoid rim. The long head of the biceps tendon functions to depress the humeral head and serves as an adjunct anterior stabilizer of the shoulder. With a SLAP tear, any traction on the biceps tendon will cause pain in the shoulder.

Pathogenesis

The labrum acts to enhance the relatively shallow, concave glenoid and increase the effective diameter of the glenoid, improving joint stability. Remember, however, that a SLAP tear is NOT a problem of shoulder instability. In other words, you are not at increased risk of dislocating your shoulder with a SLAP tear.

The most common mechanisms for SLAP tears include forceful traction loads to the arm, direct compression loads, and repetitive overhead activities (ex. throwing, pitching, or serving). A direct traction injury to the biceps tendon can also cause a SLAP tear. However, it is important to note that up to one third of patients with SLAP lesions have no preceding history of trauma.

Natural History

A conservative, nonoperative approach to treating SLAP tears is usually unsuccessful. Furthermore, simple debridement of unstable SLAP tears (type II and IV) is generally not recommended due to poor post-operative results.

Patient History and Physical Examination

Forceful traction and compression of the shoulder are the two primary mechanisms of injury resulting in a SLAP tear. Remember, however, that approximately one third of patients presenting with a SLAP tear report no history of shoulder trauma. This injury should be considered in a patient that reports persistent shoulder pain that is associated with mechanical symptoms such as catching or locking. The symptoms are usually exacerbated by overhead exercises or activities (ex. throwing a ball or extending the hand above the head). Some special tests a physician may perform to help diagnose a SLAP tear include Speed and Yergason’s Tests, O’Brien’s Test, and the Load-Compression Test. However, there is no single test that can reliably predict a SLAP tear. Rather, the clinician should use a combination of the patient’s history, physical examination findings, and a high clinical index of suspicion given the patient’s presentation, along with advanced imaging, to make the diagnosis.

Imaging and Diagnostic Studies

Although arthroscopy is the most accurate way to diagnose a SLAP tear, magnetic resonance imaging (MRI) can be used in conjunction with contrast arthrography dye (gadolinium) to examine the superior glenoid labrum. And MRI combined with intra-articular contrast is called an MR-Arthrogram and is generally considered the gold standard (aside from arthroscopy) to diagnosing a SLAP tear.

Differential Diagnosis

  • Glenohumeral Instability

  • Rotator Cuff Pathology

  • Acromioclavicular (AC) Joint Pathology

  • Intra-articular biceps tendinopathy

  • Bankart labral tear

Nonoperative Treatment

A common nonoperative and conservative treatment approach to SLAP tears is physical therapy. Although physical therapy can improve strength and range of motion (ROM) by focusing on the rotator cuff and scapular stabilizers, many patients continue to experience the symptoms of a SLAP tear. An alternative option is an intra-articular corticosteroid injection, which tends to be a therapeutic treatment to help alleviate the symptoms for a period of time.

Surgical Treatment

Surgical treatment of SLAP tears should be considered for patients who have persistent symptoms despite an appropriate course of conservative management. A failure of physical therapy along with persistent shoulder symptoms, in combination with a positive physical examination and advanced diagnostic imaging, should propogate the discussion of surgical intervention. SLAP tears can be managed by one of three surgical strategies: 1) SLAP repair; 2) Biceps tenotomy; or 3) Biceps tenodesis.

For younger, active patients with no previous history of shoulder surgery, an arthroscopic SLAP repair is usually the surgery of choice. Here, a combination of suture anchors are used to re-attach the torn superior labrum back onto the superior glenoid rim. The primary goal of a SLAP repair is to stabilize the biceps anchor and address any co-existing pathology. A biceps tenodesis procedure should be considered for severely degenerative or intractible cases.

Here is an example of a SLAP repair by Dr. Dold.

Post-Operative Care

0-4 Weeks: Patient will need to wear a sling at all times with the exception of hygiene and all active ROM exercises except external rotation in abduction can be performed after 2 weeks.

4 Weeks: Discontinue sling and begin passive ROM exercises with emphasis on posterior capsular stretching.

6 Weeks: External rotation in abduction is allowed and the patient may now begin strengthening exercises.

3 Months: Being return to sports. No throwing until 4 months post-op.

 Dr. Dold’s customized rehabilitation protocol will be given to you at the time of surgery. Physical therapy generally starts within a week of surgery and continues for 4-5 months following the surgery.

Risks

  • Infection (Rare)

  • Brachial Plexus Neuropathy

  • Persistent Pain or a recurrent SLAP tear (usually requires repeat surgery for biceps tenodesis or occasionally a revision repair).

Clinical Studies:

Dr. Dold’s most recent SLAP book chapter: Type 2 SLAP tear in a 22 year old male with associated Buford complex treated with SLAP repair with care to avoid overconstraining anteriorly. In The Biceps and Superior Labrum Complex pp 173-186.

Results of arthroscopic repair of type II superior labral anterior posterior lesions in overhead athletes: assessment of return to preinjury playing level and satisfaction. AJSM 2011.

Clinical and radiological outcomes of type 2 superior labral anterior posterior repairs in elite overhead athletes. AJSM 2013.

Return to play after Type II superior labral anterior-posterior lesion repairs in athletes: a systematic review. CORR 2012.

The outcome of type II SLAP repair: a systematic review. Arthroscopy, 2010.

Diagnosis and management of superior labral anterior posterior tears in throwing athletes. AJSM 2013.

Nonoperative treatment of superior labrum anterior posterior tears: improvements in pain, function, and quality of life. AJSM 2010.

Isolated type II superior labral anterior posterior lesions: age-related outcome of arthroscopic fixation. AJSM 2009.

Superior labral tears of the shoulder: pathogenesis, evaluation, and treatment. JAAOS 2009.

SLAP lesions: anatomy, clinical presentation, MR imaging diagnosis and characterization. Eur J Radiol 2008.

   

Distal Biceps Tendon Rupture/Avulsion (Elbow)

Definition

A distal biceps tendon injury can be defined as a complete or partial rupture or avulsion of the distal biceps tendon from its distal insertion on the radial tuberosity. Distal biceps tendon ruptures are typically caused by eccentric muscle contractions. Partial ruptures are rare and usually more painful than complete ruptures as the pain for complete ruptures subsides quickly after the initial injury. Often, distal biceps tendon ruptures can be diagnosed from the deformity that forms in the anterior brachium. Risk factors for biceps tendon avulsions include anabolic steroid use, cigarette smoking, and previous tendon injury.

Anatomy

The biceps tendon inserts onto the radial tuberosity of the radius bone in the forearm, just distal to the elbow crease. The tendon has two distinct insertions: the short head of the biceps attaches distally while the long head attaches proximally. It is important to distinguish the biceps tendon from the neighboring “lacertus fibrosus” on clinical exam, which may be mistaken for an intact tendon in the antecubital fossa. Other contents of the anterior antecubital fossa include (from medial to lateral): median nerve (most medial structure), brachial artery, biceps tendon, and the radial nerve (most lateral structure).

Presentation and Motor Exam

Complete rupture of the distal biceps tendon will typically result in a “reverse Popeye sign” due to retraction of the biceps muscle belly into the mid-aspect of the upper arm. A palpable defect is often appreciated as well as a firm nodule due to the abnormal tendon that has retracted from its normal insertion point on the bone. The biceps muscle is responsible for flexion of the elbow and supination of the forearm. As a result, the strength of these two motions will be affected with biceps tendon avulsion (supination strength is more affected that elbow flexion strength).

Strength deficits following complete biceps tendon avulsion at the elbow:

  • loss of 50% sustained supination strength

  • loss of 40% supination strength

  • loss of 30% flexion strength.

The challenge for the clinician is to distinguish between complete and partial ruptures. The biceps tendon is absent in complete rupture and palpable in partial rupture (otherwise they have a very similar clinical picture).

Differential Diagnosis

  • Cubital bursitis

  • Partial tendon rupture

  • Distal biceps muscle tear

  • Elbow dislocation

  • Radial head fracture

  • Entrapment of lateral antebrachial cutaneous nerve (LABC)

Evaluation and Imaging

X-Rays are usually normal following tendon avulsion unless a piece of bone has been avulsed from the radial tuberosity along with the tendon.

An MRI is often ordered to:

  • confirm the diagnosis

  • differentiate between a complete and partial tear

  • assess the degree of retraction of the tendon

Treatment

The decision to perform surgery for primary tendon repair should be based on a comprehensive review of the risks and benefits of surgery, contrasted with the expectations of conservative management. Non-operative treatment consists of physical therapy and supportive treatment (ice, NSAID), which is sometimes indicated for older, low-demand patients who are willing to sacrifice function. Outcome following non-operative treatment for these injuries will include:

  • will lose 50% sustained supination strength

  • will lose 40% supination strength

  • will lose 30% flexion strength

  • will lose 15% grip strength

Indications for surgical repair of the tendon back down to the tuberosity include:

  • young, healthy patients who do not want to sacrifice function (as specified above).

  • partial tears that do not respond to non-operative management.

Surgical treatment should occur within a few weeks from the date of injury to avoid irreversible retraction of the tendon from its insertion point over time.

Dr. Dold utilizes an anterior, single-incision technique (utilizing an endobutton) for repair of the ruptured tendon. Dr. Dold has published on this topic and the various techniques utilized for surgical repair at Orthobullets.com. More information can be found here.

Research