Shoulder Resources

Biceps tendon lesions and SLAP lesions (R)(M) Biceps tendon lesions and SLAP lesions (R)(M)


Biceps tendonitis
This is often associated with impingement. Manifests through tenderness along the bicipital groove, and positive Speed's and Yergasun's tests.
Initial treatment is with rest, NSAIDs and occasionally a local injection of corticosteroids. Further treatment is via treatment of the impingement. Rarely, tenodesis of the biceps tendon into the proximal humerus can help relieve symptoms.

Biceps tendon subluxation
Often associated with subscapularis tear.
The tendon is unstable and displaces medially out of its groove.
Occasionally the tendon must be relocated in a deepened groove.

Proximal biceps tendon rupture
Rupture of the long head of biceps occurs in older patients, over 50, usually in conjunction with a rotator cuff tear.
While lifting something heavy the patient feels a snap and the upper arm becomes painful and bruised.
Upon flexion of the elbow the detached biceps forms a prominent lump. Elbow flexion is weak as is supination.
Treatment in older patients is non-operative; in younger patients, and in association with cuff tear, the biceps tendon stump can be tenodesed to the proximal humerus at the time of acromioplasty.
Distal biceps tendon ruptures (Ramsey, JAAOS 1999)

Anatomy notes
The bicipital aponeurosis arises from the medial aspect of the muscle belly at the junction of the musculotendinous unit and the distal biceps tendon. It runs distally and medially across the cubital fossa, blending with the fascia over the proximal flexor mass and inserts onto the subcutaneous border of the ulna. The lateral antebrachial cutaneous nerve of the forearm pierces the fascia near the musculotendinous junction of the biceps, between the biceps and the brachialis muscles, 5cm above the elbow flexion crease.

Functional biomechanics
The biceps is the strongest supinator of the forearm. It is a flexor of the forearm, strongest at 90 degrees of elbow flexion and in flexion of the supinated forearm. It has very little activity in flexion of the pronated forearm.

Epidemiology
Usually occurs in the dominant arm of men in their 40s to 60s. The average age at the time of rupture is around 50.

Aetiology
Probably secondary to intrasubstance degeneration. The typical lesion is an avulsion from the radial tuberosity. The blood supply to the biceps tendon is via a distal branch from the posterior radial recurrent artery, which enters the tendon at its insertion, so hypovascularity probably plays little role. The tendon may be squashed between the ulna and radius in full pronation, in which position the tendon takes up 85% of the available room. Hypertrophic bone is sometimes seen here, and perhaps this hypertrophic bone impinges on the tendon.

Clinical
Patients usually report a sudden extension force applied to the flexed arm, followed by a tearing sensation in the cubital fossa with sudden strong pain. The intense pain subsides in a couple of hours to be replaced by a dull ache. Subsequently the patient may complain of weakness of flexion and of supination. Physical examination reveals tenderness in the cubital fossa. The tendon may be felt to be intact, which would represent a partial rupture. With a complete tear, if the elbow is flexed the muscle belly retracts proximally. Bruising and swelling develop in the cubital fossa and track distally.

Imaging
Plain XR may reveal hypertrophy at the radial tuberosity and rarely avulsion of a segment of tuberosity.
MRI will demonstrate high signal intensity in the tract left by the tendon.
Differential diagnosis
Cubital bursitis
Bicipital tendinosis
Partial biceps tendon rupture
Entrapment of the lateral antebrachial cutaneous nerve

Treatment
Acute lesions should be managed surgically, as good return of function is expected with minimal complication. Chronic tears are more problematic, particularly if the lacertus fibrosus has also ruptured and the tendon has retracted proximally, because repair is much more difficult in this setting.

Partial rupture
If there is ongoing pain the best treatment is to divide the tendon at its insertion, debride it and reinsert it.

Complete rupture
A one or two incision technique can be used. The commonest technique is a modified Boyd-Andersen (two incision) technique. The technique was modified to avoid subperiosteal dissection of the ulna which could result in proximal radial synostosis. A single incision technique using suture anchors is becoming more common.

Modified Boyd-Andersen technique
The patient is positioned supine and a tourniquet applied. The distal end of the tendon is identified via a lazy S incision in the cubital fossa, with the proximal limb lateral. The lateral antebrachial nerve is identified as it pierces the antecubital fascia. The tendon is retrieved, minimally debrided and prepared with 3 No 5 Ethibond sutures. The tract for the biceps tendon is usually easily identified. An artery clip is passed down the tract with the forearm in supination and directed laterally, to avoid violating the ulnar periosteum. A 2 nd incision is made over the artery clip, and carried down as a muscle splitting incision to the radial tuberosity. The tuberosity is excavated out with a high speed burr, and drill holes created. The tendon is tied into the trough in the tuberosity. The elbow is immobilized in neutral rotation and 90 degrees of flexion.

Chronic repair
Specific problems:
• Scarring with obliteration of the tract
• Careful dissection is needed to identify or create the tract for the tendon. The radial and posterior interosseous nerves should be identified.
• Inadequate biceps length
• This can be addressed with fascia lata or semitendinosis autograft

Rehabilitation
The arm is immobilized as above for a week. Passive ROM is then started for 8 weeks with a 30 degree extension block. After this unrestricted motion and progressive strengthening begins. Full strenuous lifting is not allowed for 5 months.

Results
Nonoperative management of tears may lead to loss of up to 50% of supination or flexion power. Duckworth says supination is weakest, and patients tend to fatigue easily. In repair of acute tears approximately 90-95% of preinjury strength can be achieved. Chronic repairs are not as effective. One study achieved around 85% strength.

Complications
• Radial nerve injury
• Weakness
• Proximal radial synostosis

SLAP lesions
Definition : A lesion of the superior glenoid labrum resulting in instability and pain, found particularly in throwing athletes.

History
First described by Andrews in 1985.

Anatomy
The labrum is a triangular fibrocartilaginous structure. The inferior and posterior aspects of the labrum are relatively uniform but the anterior and superior aspects show some variation. The insertion of the superior labrum into the glenoid resembles a meniscus, with a central free edge. The posterosuperior labrum contributes strongly to the long head of biceps. The biceps may arise more from the labrum than the supraglenoid tubercle. There are many anatomical variants, and some degree of fibrillation of the superior labrum is considered to be normal. Sublabral holes are also considered normal.
The Buford complex is a variation in normal anatomy that consists of a large anterosuperior foramen with a cordlike MGHL, seen in around 1.5% of shoulders. The vascularity of the labrum is decreased superiorly and anteriorly.

Functional importance of the biceps
The long head of biceps acts as a humeral head depressor, but also has a role in anterior stability of the humerus. In the abducted and externally rotated position, the long head of biceps has the ability to limit external rotation at the GH joint. The presence of a SLAP lesion decreases this restraint. A SLAP lesion also leads to increased forces on the IGHL, which might lead to failure of the ligament.

Aetiology
Probably due to instability of the glenohumeral joint. The original proposal of Andrews was that the biceps tendon was avulsed along with the labrum during the follow through phase of throwing. In Snyder's series the most common mechanism of injury was falling onto an outstretched arm. The next most common causes are traction injuries and then dislocation or subluxation.

Clinical
The patient may complain of a painful click on attempting to elevate the humerus, and a loss of power in overhead positions. There may be catching, locking or popping. The pain is often indistinguishable from impingement. Patients commonly present with findings suggestive of rotator cuff pathology or instability; patients commonly have positive Neer and Hawkins signs, and apprehension tests.

O'Brien's test may be positive: the elbow is extended, the shoulder flexed to 90 degrees and adducted 30 to 45 degrees, and internally rotated so the thumb points down. This position places the biceps tendon under tension and in direct contact with the anterosuperior labrum. The patient then attempts to resist the examiner's attempts to depress the arm from this position. Deep anterior shoulder pain and weakness, which is relieved as the arm is rotated to the thumbs up position, is suggestive of a SLAP lesion. If the pain is over the AC joint this is more suggestive of AC joint arthritis. Diagnosis is difficult, particularly because of the common coexistence of SLAP lesions and instability, and the definitive diagnosis can only be made at arthroscopy.

Imaging
Optimal imaging study is gadolinium enhanced MRI.

Arthroscopy
Around 75% of SLAP lesions are associated with other pathology, typically rotator cuff lesions (40%), Bankart lesions and AC joint pathology.
Classification of SLAP lesions (Snyder and Maffet)
Type I Fraying and degeneration of the superior labral edge, with a well-fixed biceps anchor.
Type II Labral and biceps anchor detachments from the superior glenoid. Sub classified into IIA (anterosuperior), IIB (postero-superior) and IIC (combined anterior and posterior).
Type III Bucket handle tear of the superior labrum only with the biceps anchor intact.
Type IV Bucket handle tear of the superior labrum with the tear extending into the biceps anchor.
Type V Bankart lesion extending up into a type II lesion.
Type VI Unstable flap tear of labrum along with biceps tear avulsion.
Type VII Superior labral and biceps tendon separation extending anteriorly, inferior to the middle glenohumeral ligament.

Treatment
Simple debridement alone is unsuccessful in the treatment of SLAP lesion; while reasonable results are seen at one year (78% excellent pain relief) by two years this has declined to 63% at 2 years, with only 45% performing at prior levels of athletic performance.

Type I lesions - Do not debride but examine carefully for presence of instability.
Type II lesions - Should repair the labrum using suture anchors, or bio-resorbable screws. Arthroscopic repairs have less morbidity.
Type III lesions - Debride/excise the bucket handle fragment (some repair the bucket handle if it is huge).
Type IV lesions - Repair or tenodesis of tendon based on symptoms and condition of remaining tendon
Type V lesions - Stabilize labral tear and bucket handle SLAP lesion
Type VI lesions - Debride superior flap tear
Type VII lesion - Repair and stabilize

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