Latissimus dorsi rupture

1. High-Yield Summary

• Latissimus dorsi (LD) tendon ruptures are uncommon, high-morbidity sports injuries occurring almost exclusively in elite overhead athletes (professional baseball pitchers during late cocking and acceleration phases), competitive water-skiers, and heavy resistance athletes.
• Pathoanatomic failure exhibits two distinct patterns: humeral insertion avulsions from the floor of the bicipital groove (amenable to anatomic surgical refixation) and myotendinous junction (MTJ) tears (managed virtually exclusively with nonoperative rehabilitation).
• Clinical diagnosis is characterized by acute posterior axillary and flank pain, audible popping, palpable posterior axillary fold defect, ecchymosis tracking down the medial arm and lateral chest wall, and weakness on resisted internal rotation and adduction.
• High-resolution dedicated axillary-protocol MRI is the diagnostic gold standard; conventional shoulder MRI protocols frequently truncate the field of view and fail to capture the distal humeral insertion and degree of retraction.
• Nonoperative management yields successful return-to-play rates exceeding 90% in professional pitchers at 3 to 4 months, while acute primary surgical repair is indicated for complete humeral tendon avulsions in elite throwers and high-demand athletes requiring maximum power.

2. Anatomy

The latissimus dorsi is a broad, triangular, flat muscle covering the lumbar and lower thoracic back. It originates from the spinous processes of vertebrae T7 through T12, the thoracolumbar fascia, the posterior third of the iliac crest, the lower three or four ribs, and typically by muscular slips from the inferior angle of the scapula. The muscle fibers converge superolaterally toward the axilla, executing an obligatory 180-degree torsion: fibers originating most superiorly insert most inferiorly on the humerus, whereas lower lumbar and pelvic fibers twist to insert superiorly.

The latissimus dorsi tendon measures approximately 7 cm in length, 2.5 to 3.0 cm in width, and 1 to 2 mm in thickness. It inserts into the floor of the intertubercular (bicipital) groove of the humerus, situated immediately anterior to the teres major tendon and medial/posterior to the pectoralis major tendon (the classic surgical mnemonic: “a Lady between two Majors”). A constant adventitial bursa separates the latissimus dorsi tendon from the adjacent teres major tendon and humeral cortex.

Neurovascular Corridors and Danger Zones:

• Thoracodorsal Nerve (C6–C8): Arises from the posterior cord of the brachial plexus and travels alongside the thoracodorsal artery and veins (branches of the subscapular axis). The neurovascular bundle penetrates the deep, anterior surface of the latissimus dorsi muscle belly approximately 8 to 10 cm medial to its humeral insertion. Surgical mobilization within 5 cm medial to the humeral insertion is generally safe; aggressive medial traction or blind deep dissection risks devastating neuropraxia and muscle denervation.
• Radial Nerve: Traverses the triangular interval (bounded by the teres major, long head of triceps, and humeral shaft) immediately anterior and deep to the latissimus dorsi tendon before entering the spiral groove. During surgical exposure and suture passage at the humeral footprint, the radial nerve is vulnerable to direct laceration, entrapment, or traction injury.
• Axillary Nerve and Posterior Circumflex Humeral Artery: Traverse the quadrangular space immediately superior to the teres major tendon. Retraction along the superior border of the operative field must avoid superior tethering or stretch injury to the axillary nerve.

Surgical Internervous Plane: For posterior axillary approaches, exposure is developed through the interval between the latissimus dorsi (innervated by the thoracodorsal nerve) and the teres major (innervated by the lower subscapular nerve), or along the superficial interval between the posterior border of the deltoid (axillary nerve) and the long head of the triceps (radial nerve).

3. Pathogenesis

The latissimus dorsi serves as a powerful adductor, internal rotator, and extensor of the glenohumeral joint. During overhead throwing, it plays a critical biomechanical role by providing active inferior humeral head depression and generating massive internal rotation torque, thereby stabilizing the joint and counteracting tremendous distracting forces during deceleration.

Mechanism of Injury in Throwing Athletes: In baseball pitchers, failure occurs most commonly during the transition from the late cocking phase (characterized by maximal shoulder external rotation, abduction, and scapular retraction) to early acceleration. In this phase, the latissimus dorsi undergoes violent eccentric lengthening while simultaneously firing at peak activation to initiate internal rotation. The resultant tensile and shear stresses exceed the ultimate tensile strength of the tendon or myotendinous junction, precipitating acute rupture.

Mechanism in Power and Water Sports: In water-skiers and wakeboarders, acute avulsion occurs during sudden, high-speed eccentric traction on a forward-flexed and abducted arm when catching a ski tip in the water. In powerlifters, rupture typically occurs during the lockout phase of heavy deadlifts or during eccentric loading in wide-grip pull-downs or bench pressing, where immense tensile loads exceed structural tolerance.

4. Natural History

Latissimus dorsi rupture is an uncommon injury in the general population, with fewer than 100 cases documented in orthopaedic literature. It occurs almost exclusively in males between 18 and 40 years of age who engage in high-velocity overhead sports, steer wrestling, or high-load resistance training. In professional baseball cohorts, isolated latissimus dorsi tears account for approximately 50% to 60% of cases, while concomitant injury to the teres major tendon or MTJ occurs in 40% to 50% of athletes.

When managed conservatively, myotendinous junction injuries heal with fibrous scar tissue, permitting functional compensation by the subscapularis, pectoralis major, and intact teres major fibers. Sedentary individuals and recreational athletes rarely experience functional impairment in activities of daily living. However, in elite overhead throwers with full-thickness humeral avulsions left untreated, chronic mechanical deficits may emerge, including permanent loss of ball velocity (2 to 5 mph), early kinetic fatigue, inconsistent release points, and chronic posterior shoulder pain during follow-through.

5. Clinical Presentation

History

Patients report a sudden, sharp, tearing sensation or distinct audible “pop” in the posterior axilla or posterolateral chest wall during a maximal throwing pitch, water-ski pull, or resistance lift. Immediate loss of power occurs, precluding further athletic participation. Patients describe sharp focal pain exacerbated by deep inspiration, coughing, or reaching behind the back, followed over the subsequent 24 to 48 hours by progressive swelling and extensive bruising tracking down the medial arm and along the lateral thoracic wall.

Physical Exam

A systematic physical examination includes inspection, palpation, and targeted provocative testing:

• Visual Inspection: Evident asymmetry or blunting of the posterior axillary fold compared to the contralateral shoulder. Prominent ecchymosis frequently tracks along the posterior axilla, medial arm, and down the latissimus muscular flank.
• Palpation: Acute point tenderness over the posterior axillary fold and the proximal humeral bicipital groove. In acute complete avulsions, a palpable defect or sulcus can be appreciated in muscular athletes prior to significant hematoma accumulation.
• Latissimus Dorsi Cough Test: The examiner grasps the muscular belly of the posterior axillary fold between the thumb and fingers while instructing the patient to cough forcefully. In an intact muscle, a crisp, synchronous muscular contraction is palpated; absence of contraction or a palpable gap indicates complete tendon or muscular discontinuity.
• Resisted Internal Rotation and Adduction: The patient’s arm is positioned in neutral rotation and 0 degrees of abduction with the elbow flexed to 90 degrees. Manual resistance against internal rotation and adduction reproduces focal posterior axillary pain and demonstrates noticeable strength deficits.
• Resisted Pull-down Maneuver: With the arm positioned at 90 degrees of abduction and external rotation, the patient attempts to pull down into extension and adduction against examiner resistance. Weakness and reproduction of posterolateral thoracic pain are highly sensitive for latissimus and teres major pathology.

6. Imaging and Diagnostic Studies

Plain Radiography: Standard shoulder views (true anteroposterior, scapular Y, and axillary lateral) should be obtained to exclude osseous avulsion fractures from the bicipital groove, proximal humeral fractures, or lesser tuberosity avulsions. Plain radiographs are typically unremarkable in soft tissue ruptures but provide essential baseline osseous screening.

Magnetic Resonance Imaging (MRI): MRI is the definitive imaging modality of choice. Standard shoulder MRI protocols have a restricted field of view centered on the glenohumeral joint and rotator cuff, which frequently truncates the latissimus dorsi insertion on the proximal humeral shaft. Therefore, a dedicated large-field-of-view axillary protocol or proximal humerus MRI must be explicitly requested.

• Axial T2-Weighted and STIR Sequences: Demonstrate hyperintense fluid and hematoma replacing the low-signal-intensity tendon at the bicipital groove floor, confirming avulsion and quantifying the degree of medial and inferior retraction.
• Coronal and Sagittal Sequences: Delineate whether the rupture involves the distal tendon, the myotendinous junction (characterized by feathery muscular edema and strain), or muscle belly, and critically evaluate the integrity of the adjacent teres major muscle and tendon.

Diagnostic Ultrasound: High-resolution dynamic ultrasonography can rapidly confirm tendon discontinuity, hematoma, and dynamic retraction during active internal rotation. However, ultrasound is operator-dependent and less reliable than MRI for evaluating deep muscular retraction and concomitant teres major involvement.

7. Classification

Latissimus dorsi injuries are classified anatomically based on the precise zone of structural failure, which directly determines surgical candidacy and rehabilitation trajectory:

8. Treatment

Medical / Nonoperative

Nonoperative management is the primary treatment for all Type I (MTJ) tears, low-demand recreational patients, and selected overhead throwers presenting with partial tears or isolated stable lesions:

• Phase 1 (Acute Protection, Weeks 0–2): Sling immobilization for comfort, cryotherapy, multimodal non-opioid analgesia, and passive range of motion restricted to under 90 degrees of forward flexion and external rotation to protect healing tissue.
• Phase 2 (Restoration of Mobility, Weeks 2–6): Discontinuation of sling; progression to full active-assisted and active range of motion; scapular retractor and rotator cuff isometric strengthening in neutral adduction.
• Phase 3 (Strengthening & Neuromuscular Control, Weeks 6–10): Progressive isotonic and eccentric latissimus strengthening; core and kinetic chain integration; high-level periscapular stabilization.
• Phase 4 (Interval Return to Throwing, Weeks 10–16): Initiation of a structured interval throwing program off flat ground upon achieving full, painless range of motion and at least 90% symmetric strength compared to the contralateral limb; gradual progression to mound throwing over 4 to 6 weeks.

Operative

Goals of Surgery: Anatomic restoration of the latissimus dorsi footprint onto the intertubercular groove, re-establishment of resting length-tension biomechanics, rigid mechanical fixation to facilitate early motion, and protection of the adjacent radial and thoracodorsal neurovascular structures.

Primary Surgical Approaches:

• Posterior Axillary Approach: The patient is positioned in the lateral decubitus position with the operative arm supported in an articulated arm holder. An incision is fashioned along the posterior axillary fold. Deep dissection exposes the retracted latissimus tendon. The radial nerve is palpated and protected anterior and medial to the humeral shaft. High-strength nonabsorbable braided sutures (e.g., #2 FiberWire) are placed through the tendon in a locking Krackow configuration. The humeral insertion footprint is decorticated to bleeding bone, and refixation is achieved using either dual cortical endosteal buttons or high-strength suture anchors.
• Anterior Deltopectoral Approach: Employed when the surgeon prefers a supine position or when addressing concomitant anterior shoulder pathology. The distal deltopectoral interval is developed, the pectoralis major tendon is gently retracted laterally, and the biceps tendon is retracted to visualize the bicipital groove floor.

Indications & Contraindications

• Operative Indications: Complete full-thickness humeral tendon avulsion (Type IIIA or IIIB) with tendon retraction > 2 cm in professional or collegiate overhead throwers, competitive water-skiers, or elite resistance athletes; or chronic avulsion causing refractory pain, subjective instability, and functional deficit failing >=3 to 6 months of nonoperative rehabilitation.
• Contraindications: High myotendinous junction tears (Type I, high nonoperative healing potential and insufficient suture holding strength); sedentary or low-demand patients; active local infection; or medical comorbidities precluding surgery.

9. Outcome

Data-driven outcomes across modern literature reflect high success rates for both nonoperative and operative paradigms when matched appropriately to patient demand and tear subtype:

• Nonoperative Outcomes in Professional Pitchers: Clinical cohort studies by Schickendantz et al. (2009) and Nagda et al. (2011) demonstrated return-to-play rates between 90% and 100% in Major and Minor League Baseball pitchers following comprehensive physical therapy, with a mean recovery time of 89 to 100 days. Isolated latissimus dorsi injuries returned significantly faster than combined latissimus and teres major tears.
• Operative Repair Outcomes: In elite throwing athletes and water-skiers undergoing surgical refixation for complete avulsions, Erickson et al. (2017) demonstrated a 100% return-to-sport rate at pre-injury performance levels at a mean of 9.9 months postoperatively. In professional pitchers, objective metrics (earned run average [ERA], walks plus hits per inning pitched [WHIP], and fastball velocity) showed no statistically significant deterioration compared to pre-injury baseline.
• Patient-Reported Outcomes: Patients undergoing operative repair achieve significant improvements in ASES scores (mean > 92 points) and Single Assessment Numeric Evaluation (SANE) scores, with high subjective satisfaction and robust restoration of adduction and internal rotation strength.

10. Complications

Complications following latissimus dorsi rupture and its management are categorized chronologically:

11. Pearls and Pitfalls

• Pearl (MRI Ordering): Always explicitly request an “extended axillary protocol” or “proximal humerus MRI” when suspecting latissimus pathology. Standard shoulder MRIs stop at the surgical neck and miss retracted tendon stumps, leading to false-negative reads.
• Pearl (Intraoperative Arm Positioning): Position the humerus in 30 degrees of extension and neutral-to-slight internal rotation during suture anchor placement and knot tying. This relieves tension on the tendon repair and brings the intertubercular groove directly into the operative corridor.
• Pearl (Radial Nerve Protection): The radial nerve lies directly anterior to the latissimus insertion on the humerus. Keep your subperiosteal dissection strictly on the lateral border of the bicipital groove and avoid placing sharp retractors anteriorly across the humeral shaft.
• Pitfall (Misdiagnosed Rotator Cuff Pathology): Mistaking posterior axillary ecchymosis and pain for an atypical rotator cuff or triceps tear. Overlooking latissimus avulsion in an elite pitcher leads to prolonged unguided rest, muscle retraction, and lost surgical window.
• Pitfall (Operating on MTJ Tears): Attempting surgical repair of Type I myotendinous junction ruptures. Muscle tissue holding strength is poor, resulting in suture cut-out and high failure rates; MTJ tears should virtually always be managed nonoperatively.

12. Controversy

Acute Operative Refixation vs. Nonoperative Trial in Professional Pitchers: A persistent debate exists regarding whether professional baseball pitchers with full-thickness humeral tendon avulsions should undergo immediate surgical repair or an initial trial of nonoperative rehabilitation. Proponents of nonoperative therapy cite Nagda et al. and Schickendantz et al., noting that >90% of pitchers return to competition within 3 to 4 months without surgical risks. Conversely, surgical advocates highlight that pitchers managed nonoperatively occasionally suffer recurrent spasms, subjective velocity deficits, or late failures, whereas acute anatomic refixation restores structural biomechanics with a predictable return to pre-injury performance metrics, albeit requiring 8 to 10 months of recovery.

Fixation Construct: Suture Anchors vs. Cortical Endosteal Buttons: Debate continues regarding the optimal biomechanical fixation method at the bicipital groove floor. The humeral cortex in the floor of the groove is thin (frequently 1 to 2 mm). While double-row suture anchors provide broad footprint compression, unicortical or bicortical endosteal button constructs offer superior tensile pullout strength and eliminate the risk of anchor loosening during aggressive early rehabilitation.

13. Evidence-Based Synthesis

Modern clinical decision-making is grounded in high-quality randomized controlled trials and prospective registry analyses, corroborated by seminal biomechanical and anatomical descriptions.

14. References

• George MS, Khazzam M. Latissimus Dorsi Tendon Rupture. J Am Acad Orthop Surg. 2019. doi:10.5435/JAAOS-D-17-00581 [Level IV: Comprehensive Clinical Review]
• Schickendantz MS, Kaar SG, Meister K et al. Latissimus dorsi and teres major tears in professional baseball pitchers: a case series. Am J Sports Med. 2009. doi:10.1177/0363546509335198 [Level IV: Clinical Case Series]
• Nagda SH, Cohen SB, Noonan TJ et al. Management and outcomes of latissimus dorsi and teres major injuries in professional baseball pitchers. Am J Sports Med. 2011. doi:10.1177/0363546511422219 [Level IV: Comparative Cohort Study]
• Erickson BJ, Chalmers PN, Waterman BR et al. Performance and return to sport in elite baseball players and recreational athletes following repair of the latissimus dorsi and teres major. J Shoulder Elbow Surg. 2017. doi:10.1016/j.jse.2017.05.015 [Level IV: Clinical Cohort Study]
• Erickson BJ, Chalmers PN, D’Angelo J et al. Performance and Return to Sport After Latissimus Dorsi and Teres Major Tears Among Professional Baseball Pitchers. Am J Sports Med. 2019. doi:10.1177/0363546519829086 [Level IV: Epidemiologic Cohort Study]

15. Master Class Pro-Tip

When performing open refixation of a retracted latissimus dorsi tendon, mobilizing the tendon stump requires absolute anatomical vigilance. Adhesions frequently tether the retracted tendon to the underlying radial nerve and anterior humerus. Dissect sharply directly on the glistening epitenon of the latissimus, staying within 4 cm of the tendon edge. During humeral bed preparation, create a bleeding osseous trough at the intertubercular groove floor using a high-speed burr, and tension the repair with the humerus in 20 to 30 degrees of extension and neutral rotation. Securing the tendon with heavy nonabsorbable suture tape utilizing bicortical button fixation achieves superior pullout strength in this thin cortical zone, allowing early passive pendulums without endangering footprint stability.

Master Class Surgical Pearl: Latissimus Dorsi Tendon Refixation