INTRODUCTION TO TENDON AND MUSCLE RUPTURES
The management of acute and chronic musculotendinous ruptures requires a profound understanding of regional biomechanics, patient-specific functional demands, and the intrinsic healing capacity of the affected tissues. While some musculotendinous units, such as the adductor longus, demonstrate robust recovery with conservative management, others, such as the gluteus medius or the proximal biceps in high-demand patients, necessitate meticulous surgical restoration to prevent long-term functional deficits. This chapter provides an exhaustive, evidence-based framework for the diagnosis, non-operative management, and surgical reconstruction of adductor longus, proximal biceps, and gluteal tendon ruptures.
RUPTURE OF THE ADDUCTOR LONGUS MUSCLE
Pathoanatomy and Mechanism of Injury
The adductor longus is the most frequently injured muscle in the medial compartment of the thigh. Originating from the anterior body of the pubis and inserting onto the linea aspera of the femur, it serves as a primary adductor and secondary flexor of the hip. Ruptures typically occur at the proximal musculotendinous junction, though avulsions from the pubic symphysis are also documented.
The classic mechanism of injury involves a sudden, forceful eccentric contraction. This is frequently observed in soccer, ice hockey, and American football athletes. The biomechanical vector usually combines wide abduction of the thighs with simultaneous flexion of one hip and internal rotation of the contralateral hip, placing maximal tensile stress on the adductor longus origin.
Clinical Presentation and Evaluation
Patients typically present with the sudden or gradual appearance of swelling and ecchymosis on the medial aspect of the upper third of the thigh. A history of an acute traumatic event is common but may be inconstant in chronic tendinopathic cases.
- Palpation: A distinct palpable defect or mass (the retracted muscle belly) is often appreciated. This mass becomes significantly more prominent during resisted contraction of the adductor musculature.
- Associated Pathology: It is critical to evaluate for concomitant core muscle injuries ("sports hernia"). In a cohort of 19 National Football League (NFL) players with adductor ruptures, nearly half (9 players) reported a preceding history of abdominal or groin pain, highlighting the interconnected biomechanics of the pubic symphysis and the rectus abdominis-adductor aponeurosis.
Clinical Pearl: Always evaluate the contralateral hip and the lower abdominal musculature. The "pubic joint" acts as a fulcrum; weakness or chronic injury in the rectus abdominis often predisposes the adductor longus to acute rupture due to altered pelvic kinematics.
Management Strategies
Non-Operative Management (The Gold Standard)
Surgical repair of adductor longus ruptures is notoriously difficult and often yields suboptimal results when the tear occurs at the musculotendinous junction due to poor tissue quality for suture purchase. Consequently, conservative therapy is the mainstay of treatment and is highly successful.
- Acute Phase (0-2 Weeks): Cryotherapy, thigh compression using a specialized neoprene thigh sleeve, and relative rest. Crutches are utilized to unload the extremity until the patient can ambulate without an antalgic gait.
- Rehabilitation Phase (2-6 Weeks): Once the acute inflammatory response subsides, progressive stretching and strengthening exercises are initiated. Rehabilitation must focus on the entire pelvic girdle, concentrating on the adductors, abductors, and core stabilizers.
- Outcomes: Minimal functional deficit is expected. Evidence strongly supports non-operative management in elite athletes. In a definitive study of NFL players, non-operative treatment resulted in a significantly faster return to play (average 6 weeks) in 14 players compared to operative repair in 5 players (average 12 weeks).
Operative Management
Operative intervention is strictly reserved for massive, complete avulsions directly from the pubic footprint in high-level athletes who fail conservative management, or in cases of chronic, debilitating pain with severe weakness.
- Surgical Approach: A medial longitudinal incision is made over the palpable defect. Care is taken to protect the anterior branch of the obturator nerve.
- Fixation: If avulsed from the bone, the tendon is mobilized, debrided to healthy tissue, and reattached to the pubic body using double-loaded suture anchors.
Surgical Warning: Avoid over-tensioning the repair. The adductor longus excursion is significant; over-tensioning will lead to postoperative stiffness, loss of abduction, and a high risk of re-rupture.
RUPTURE OF THE PROXIMAL BICEPS TENDON
Pathoanatomy and Diagnostic Challenges
The long head of the biceps (LHB) tendon originates from the supraglenoid tubercle and the superior glenoid labrum. It acts as a dynamic depressor of the humeral head and a secondary stabilizer of the glenohumeral joint. Rupture of the proximal biceps tendon is frequently the end-stage result of chronic microtrauma, bicipital tendinosis, and subacromial impingement.
One of the primary difficulties in the diagnosis of an isolated proximal biceps tendon rupture is determining whether the rupture is associated with concomitant rotator cuff tears or underlying glenohumeral instability. The clinical presentation—anterior shoulder pain, weakness, and a positive "Popeye" deformity (distal migration of the muscle belly)—is strikingly similar to that of a patient with a massive rotator cuff tear.
Clinical Evaluation
- Physical Examination: Standard tests for rotator cuff injury (e.g., Jobe's test, external rotation lag sign) and biceps pathology (Speed’s test, Yergason’s test) are mandatory.
- Imaging: In patients with a history of impingement symptoms who present with an acute LHB rupture, arthrography or Magnetic Resonance Imaging (MRI) is essential to evaluate for hidden rotator cuff pathology.
Management Strategies
Non-Operative Management
Historically, ruptures of the proximal biceps tendon have been treated non-operatively because they rarely cause significant functional impairment in activities of daily living. The primary deficits are a cosmetic "Popeye" deformity and a 10% to 20% loss of peak supination strength. Non-operative management is highly appropriate for elderly, sedentary patients, or those with low functional demands.
Operative Management: Indications and Patient Selection
Operative repair is indicated in specific patient populations:
1. Young, Active Patients: Those who are unwilling to accept the cosmetic deformity or the slight weakness in supination and elbow flexion.
2. High-Demand Professionals: Middle-aged patients whose professions (e.g., carpentry, heavy manual labor) require maximal, sustained supination strength. In these cases, the patient must accept that the time out of work for rehabilitation is outweighed by the functional power gained.
3. Concomitant Pathology: Patients undergoing surgical intervention for impingement syndrome or rotator cuff tears. In an active patient younger than 40 years old with a rupture of less than 1 year’s duration, biceps tenodesis should be performed concomitantly with acromioplasty, resection of the coracoacromial ligament, and rotator cuff repair.
Surgical Techniques: Tenotomy vs. Tenodesis
Biceps Tenotomy
Tenotomy is a technically simple procedure involving the arthroscopic release of the LHB from its superior labral attachment without subsequent fixation.
* Indications: Older, less active patients who do not object to supination weakness or the cosmetic deformity.
* Advantages: Short rehabilitation time, immediate pain relief, and no requirement for postoperative immobilization.
Biceps Tenodesis
Tenodesis involves securing the LHB tendon to the proximal humerus, maintaining the resting length and tension of the muscle. Techniques vary from open approaches to a mini-open subpectoral approach, to all-arthroscopic techniques.
- Mini-Open Subpectoral Tenodesis: This is the preferred technique for active patients as it removes the tendon from the bicipital groove entirely, eliminating groove-related pain.
- Positioning: Beach chair or lateral decubitus.
- Approach: A 3 cm longitudinal incision is made centered over the inferior border of the pectoralis major tendon in the axillary fold.
- Tendon Retrieval: The LHB is identified deep to the pectoralis major fascia and retrieved.
- Fixation: Fixation can be achieved utilizing cortical button suspensory fixation, interference screws, or suture anchors. The tendon is tensioned appropriately (usually 1 cm of tendon resected for every 1 cm of retraction) and secured into a unicortical bone tunnel in the bicipital groove.
Pitfall: Failure to identify and treat concomitant subscapularis tears during biceps tenodesis can lead to persistent anterior shoulder pain and poor functional outcomes. Always probe the superior border of the subscapularis during arthroscopy.
RUPTURE OF GLUTEUS MEDIUS AND MINIMUS TENDONS
Pathoanatomy: The "Rotator Cuff of the Hip"
The gluteus medius and minimus muscles are the primary abductors of the hip and essential stabilizers of the pelvis during the single-leg stance phase of gait. Their tendinous insertions onto the greater trochanter anatomically and biomechanically mirror the rotator cuff of the shoulder.
* Gluteus Medius: Inserts onto the superoposterior and lateral facets of the greater trochanter.
* Gluteus Minimus: Inserts onto the anterior facet of the greater trochanter.
Avulsion or rupture of these tendons is a frequently missed diagnosis, often erroneously labeled as recalcitrant greater trochanteric pain syndrome (GTPS) or trochanteric bursitis. The etiology of tendinosis and subsequent rupture is multifactorial, likely related to local mechanical friction (iliotibial band overriding the trochanter), chronic microtrauma, or predisposing systemic conditions (e.g., fluoroquinolone use, corticosteroid injections).
Epidemiology and Clinical Presentation
The exact incidence of spontaneous gluteal ruptures in the general population remains unknown. However, iatrogenic or degenerative tears are highly prevalent:
* Reported in 4% to 20% of patients undergoing total hip arthroplasty (THA).
* Present in approximately 25% of patients with displaced femoral neck fractures.
* Spontaneous ruptures predominantly affect women older than 50 years of age.
Clinical Signs:
The two most reliable clinical signs of a gluteus medius/minimus rupture are:
1. Trendelenburg Gait: A compensatory drop of the contralateral pelvis during the stance phase on the affected limb.
2. Pain on Resisted Hip Abduction: Tested in the lateral decubitus position.
Both signs demonstrate a specificity and sensitivity exceeding 70% for gluteal tendon pathology.
Diagnostic Imaging
- Radiographs: Plain anteroposterior (AP) and lateral radiographs of the hip are usually unremarkable in acute settings. In chronic tears, they may reveal cortical sclerosis, an irregular border, or traction osteophytes at the anterior and lateral edges of the greater trochanter.
- MRI: The gold standard for diagnosis, boasting a 91% accuracy rate. Coronal T2-weighted sequences best visualize peritrochanteric fluid, tendon discontinuity, and fatty infiltration or atrophy of the muscle bellies (Goutallier classification).
- Ultrasound: A highly effective, dynamic, and cost-efficient modality for confirming the diagnosis, particularly in the hands of an experienced musculoskeletal radiologist.
Management Strategies
Conservative Management
If diagnosed early, partial tears and acute non-retracted ruptures can be managed conservatively.
* Protocol: Unloading the involved hip with crutches or a cane (held in the contralateral hand to reduce abductor moment arm), nonsteroidal anti-inflammatory drugs (NSAIDs), and targeted physical therapy once acute symptoms subside.
* Rehabilitation: Focuses on isometric abductor strengthening and core stabilization. Corticosteroid injections should be used judiciously, as they may precipitate complete rupture of a tendinopathic tendon.
Operative Management
Operative intervention is indicated for patients with full-thickness tears, severe pain, and a persistent Trendelenburg limp who have failed a minimum of 3 to 6 months of conservative therapy.
- Surgical Approach: A direct lateral or modified Hardinge approach is utilized. The iliotibial band is split longitudinally to expose the greater trochanter and the peritrochanteric space.
- Debridement and Mobilization: The conjoined tendon footprint is identified. The degenerated tendon edges are debrided back to healthy, bleeding tissue. If the tendon is chronically retracted, extensive mobilization and release of adhesions deep to the gluteus medius muscle belly are required.
- Transosseous Fixation: The footprint on the greater trochanter is decorticated to enhance biologic healing. Fixation is achieved using a double-row suture anchor construct or transosseous drill holes. The double-row technique maximizes the pressurized contact area between the tendon and the bone footprint.
- Augmentation: In cases of massive, irreparable tears or severe tissue degeneration, augmentation with a soft tissue graft (e.g., Achilles tendon allograft, acellular dermal matrix, or synthetic mesh) may be necessary to bridge the defect and restore the abductor vector.
- Endoscopic Repair: Advanced endoscopic techniques have been developed, offering the advantages of smaller incisions, less soft tissue morbidity, and faster early rehabilitation. However, this requires significant arthroscopic expertise and is generally reserved for partial or non-retracted full-thickness tears.
Clinical Pearl: Open repair of the gluteus medius and minimus tendons is highly successful, with literature reporting significant pain relief and functional restoration in 90% to 95% of patients. However, patients must be counseled that complete resolution of the Trendelenburg gait may take up to 12 months as the atrophied muscle slowly regains strength.
Postoperative Rehabilitation for Gluteal Repair
Postoperative protocols must strictly protect the repair from early tensile failure.
* Weeks 0-6: Strict protected weight-bearing (toe-touch only) with bilateral crutches. The hip is often placed in an abduction brace locked at 15 degrees of abduction to remove tension from the repair. Active abduction and passive adduction are strictly prohibited.
* Weeks 6-12: Gradual progression to full weight-bearing. Initiation of active-assisted range of motion and gentle isometric abduction exercises.
* Months 3-6: Progressive resistance training, focusing on concentric and eccentric abductor strengthening, proprioception, and gait normalization. Return to full unrestricted activity is typically permitted at 6 months postoperatively.
