Biceps Pathology — SLAP Lesions

The long head of the biceps (LHB) tendon originates from the supraglenoid tubercle and the posterosuperior labrum, traverses the glenohumeral joint intra-articularly, and exits through the bicipital groove under the transverse humeral ligament. It is subject to a spectrum of pathology — from isolated tendinitis and SLAP (Superior Labrum Anterior to Posterior) tears at its labral origin, to instability within the bicipital groove, to complete rupture. Understanding the relationship between biceps pathology, the SLAP lesion classification, and the current evidence for biceps tenodesis versus tenotomy is central to shoulder surgery practice.

• The LHB is the primary subject of controversy — its role in shoulder biomechanics remains debated; it may contribute to glenohumeral stability and acts as a weak elbow flexor and forearm supinator; many patients function well after LHB tenotomy with minimal functional deficit
• Bicipital groove anatomy: the LHB is held within the bicipital groove by the transverse humeral ligament and the roof formed by the subscapularis tendon (medially) and the supraspinatus tendon (laterally); the CHL (coracohumeral ligament) and SGHL (superior glenohumeral ligament) form the medial sling at the top of the groove; subscapularis tears allow medial subluxation of the LHB out of the groove — always examine for subscapularis pathology when LHB instability is found
• Incidence of SLAP tears: SLAP lesions account for approximately 4–8% of all shoulder arthroscopy findings; the true prevalence is higher as many are asymptomatic; more common in overhead athletes (throwers, swimmers, racket sport players)

• Types V–X: additional subtypes described by subsequent authors, including extensions into the anterior and posterior labrum and into the rotator cuff; these are less commonly encountered and involve combined labral pathology

• Biceps tendinopathy: anterior shoulder pain localised to the bicipital groove; pain reproduced with elbow flexion and forearm supination against resistance; tenderness directly over the bicipital groove (approximately 3 cm distal to the anterior acromion with the shoulder in 10° internal rotation)
• Yergason test: elbow at 90° flexion; patient supinates the forearm against resistance; positive if pain is reproduced at the bicipital groove; tests for LHB tendon pathology in the groove; sensitivity approximately 43%, specificity 79%
• Speed test: elbow extended, forearm supinated; patient flexes the shoulder against resistance from 0° to 60°; positive if pain at the bicipital groove; sensitivity approximately 54%, specificity 64%; neither Yergason nor Speed is particularly sensitive — clinical diagnosis of LHB tendinopathy relies on a combination of tests and imaging
• O`Brien active compression test (for SLAP): shoulder at 90° forward flexion and 10° adduction; elbow fully extended; (1) thumb pointing DOWN (full internal rotation) — apply downward force; (2) then palm facing UP (external rotation) — repeat; positive for SLAP if pain is reproduced in position 1 but not in position 2 (the external rotation relieves the pain by lifting the biceps off the labrum); sensitivity 63–100%, specificity 73–99% (varies widely); also positive for AC joint pathology (pain at the AC joint rather than deep in the shoulder)
• Popeye deformity: visible distal migration of the biceps muscle belly after LHB rupture; the muscle belly appears as a prominent rounded swelling in the distal arm ("Popeye" appearance); more common in older patients after degenerative LHB rupture; functional deficit is minimal in most patients

• Plain radiographs: usually normal; assess for calcification in the groove, AC joint OA, glenohumeral pathology
• MRI (or MR arthrogram): MRI arthrogram with intra-articular gadolinium is superior to standard MRI for labral pathology; MRA sensitivity for SLAP tears approximately 82–84%, specificity 90–99%; shows the biceps anchor separation (fluid signal undermining the labrum at the superior glenoid), labral tear pattern, and associated pathology (rotator cuff, glenohumeral instability); the sublabral foramen (a normal variant anterior to the biceps anchor) must be distinguished from a true Type II SLAP tear
• USS: useful for LHB tendinopathy (fluid in the sheath, tendon thickening, intratendinous degeneration), LHB subluxation (dynamic assessment), and LHB rupture; limited for intra-articular SLAP assessment
• Diagnostic arthroscopy: the gold standard for diagnosing and classifying SLAP tears; intraoperative findings (anchor stability, labral mobility on probing) are more reliable than MRI alone for surgical decision-making

Management depends on the age and functional demands of the patient, the type of SLAP lesion, and the presence of associated pathology.

• Non-operative management: for most patients initially — physiotherapy (rotator cuff strengthening, scapular stabilisation, posterior capsule stretching), NSAIDs, activity modification; subacromial or intra-articular corticosteroid injection; direct injection into the bicipital sheath for isolated LHB tendinopathy; non-operative treatment is appropriate for Type I SLAP, elderly patients with degenerative SLAP, and those who are not overhead athletes
• SLAP repair (Type II): arthroscopic repair with suture anchors placed at the supraglenoid tubercle; indicated in young overhead athletes with Type II SLAP and no significant biceps degeneration; published return-to-throwing rates in professional overhead athletes are only 63–74% — outcomes are modest; SLAP repair has fallen out of favour for older patients and is being increasingly replaced by biceps tenodesis even in younger patients in many centres
• Biceps tenotomy: simple division of the LHB tendon at its origin (intra-articular portion released); eliminates the pain source immediately; technically simple; Popeye deformity develops in approximately 40–70% of cases (more pronounced in lean muscular patients); loss of approximately 20% of supination strength and some elbow flexion strength; acceptable in older patients (>55 years), lower-demand patients, and those where cosmesis is not a priority
• Biceps tenodesis: the LHB is tenodesed to the proximal humerus (within the bicipital groove — subpectoral or suprapectoral, open or arthroscopic); the tendon is fixed at the correct tension, preventing the Popeye deformity and preserving supination strength; preferred in younger patients, active individuals, manual workers, and those concerned about cosmesis; fixation options: interference screw (most common), cortical button, suture anchor; subpectoral tenodesis (at the inferior extent of the bicipital groove, below the pectoralis major tendon) is the most distal and secure fixation, further from the pathological groove

• SLAP repair in overhead athletes — declining outcomes data: multiple systematic reviews and registry studies have shown that return-to-pre-injury level of sport after Type II SLAP repair is only achieved in 63–74% of overhead athletes; complications include stiffness (particularly loss of external rotation), failure of repair, and failure to return to sport; biceps tenodesis is increasingly preferred even in young overhead athletes as it provides equivalent or superior outcomes with lower re-operation rates in most series
• LHB medial subluxation and subscapularis: the LHB is stabilised medially within the groove by the subscapularis (upper fibres) and the transverse humeral ligament; subscapularis tears allow the LHB to sublux medially off the lesser tuberosity; medial LHB subluxation is almost pathognomonic of subscapularis tendon injury — always look for and repair the subscapularis when tenodesis is performed for a subluxated LHB; missing a subscapularis tear will result in continued anterior instability of the shoulder
• Normal variant sublabral foramen: a normal variant anterior to the biceps anchor (approximately 11–1 o`clock position on the glenoid); can be mistaken for a Type II anterior SLAP tear on MRI; the sublabral foramen is located anterior to the biceps anchor and does not involve the anchor itself; probing during arthroscopy confirms it is a normal smooth-edged variant without instability — no repair required
• Biceps tenodesis fixation tension: the correct tension for tenodesis is crucial — too loose leads to Popeye deformity and cramping; too tight limits elbow flexion; a practical guide is to tension the tenodesis with the elbow at 90° flexion and the forearm in supination, ensuring the muscle belly is in its normal resting position relative to the proximal arm

• SLAP classification: Type I fraying (debride); Type II biceps anchor detachment (most common — repair or tenodesis); Type III bucket-handle intact anchor (resect); Type IV bucket-handle extending into biceps tendon
• O`Brien test: shoulder 90° flexion, 10° adduction; pain on downward force with thumb DOWN but not with palm UP = SLAP positive; also positive in AC joint pathology (localise pain site)
• Yergason test: forearm supination against resistance at 90° elbow flexion; positive if bicipital groove pain reproduced; sensitivity 43%, specificity 79%
• Popeye deformity: LHB rupture or tenotomy; distal migration of muscle belly; cosmetic issue; minimal functional deficit in most
• Biceps tenodesis vs tenotomy: tenodesis preferred <55 years, active patients, manual workers, cosmesis; tenotomy acceptable >55 years, low demand; tenotomy has 40–70% Popeye rate
• SLAP repair return to overhead sport: only 63–74%; biceps tenodesis increasingly preferred even in young overhead athletes
• LHB subluxation = subscapularis tear until proven otherwise; repair subscapularis when tenodesis for subluxated LHB
• Subpectoral tenodesis: most distal, most secure; below pectoralis major; avoids pathological proximal groove; preferred fixation site by many surgeons
• Sublabral foramen (normal variant): anterior to biceps anchor, 11–1 o`clock; no repair needed; confirmed on arthroscopy by stable anchor with probing
• MR arthrogram: superior to standard MRI for labral pathology; sensitivity ~82–84% for SLAP; gadolinium outlines the tear