synonyms: pec major tear, pec major rupture, pec tear, pec rupture, pectoralis rupture,
Pec Rupture ICD-10
A - initial encounter
D - subsequent encounter
S - sequela
Pec Rupture ICD-9
- 840.8 (sprain/strain of other specified site of shoulder and upper arm: includes rupture of muscle)
- 905.8 Late Effects of Musculoskeletal and Connective Tissue Injuries—Late Effect of Tendon Injury
Pec Rupture Etiology / Epidemiology / Natural History
- Rare, generally follows extreme muscle contraction.
- Associated with weight lifting (bench press), and attempting to break fall with outstretched arm.
- Natural History: generally report cramping pain and weakness in shoulder and chest with activities which stress pec major such as dips, bench press etc. Asymmetric bulge in pectoralis major muscle. No rest pain or loss of motion. Pec major function is not necessary for normal shoulder function. Activities involving arm flexion, adduction, and IR may be limited especially with strenuous activity. Isokinetic adduction strength testing: acute repair = 102% of the opposite side; chronic injury repair =94%: non operative treatment=71%. (Schepsis AA, AJSM 2000;28:9).
Pec Rupture Anatomy
- Pec tendon is 5 cm wide, 1 cm long on the anterior surface, and 2.5 cm long on the posterior surface. It consists of an anterior lamina (clavicular head), and a posterior lamina is formed by the sternal head.
- The fascia surrounding the pectoralis major is continuous with the fascia of the brachium and the medial antebrachial septum. This fascia presents as a palpable cord in the axilla and may be mistaken for an intact pectoralis major tendon.
- Most common rupture is a tendon avulsion, but can be a rupture at the myotendinous junction, bony avulsion, tendon mid substance rupture, or muscle belly tear.
- Some consider three heads of origin: clavicular, sternal and abdominal (Wolfe SW, AJSM 1992;20:587)
Pec Rupture Clinical Evaluation
- Typically maximal eccentric muscular contraction with arm in abducted extended position such as during dips and bench press.
- Usually men, age 20-40, rare in women.
- Often report pop or tearing sensation in shoulder.
- Pain, limited motion, swelling, ecchymosis and weakness in anterior shoulder/chest.
- May have loss of the axillary fold. Best seen when arm is abducted 90 degrees and after swelling/ecchymosis have resolved. Always compare to normal side.
- Axillary fold may be normal do to an intact tendon sheath or an intact clavicular head anterior to an injured sternal head.
- Location of ecchymosis may help localize the location of injury; anterior chest ecchymosis = muscle belly tear, axilla/arm ecchymosis = tendon avulsion.
Pec Rupture Xray / Diagnostic Tests
- AP, scapular lateral and axillary views. Generally normal, may show avulsion fracture of the proximal humerus.
- Characteristic finding = soft-tissue swelling and absence of the pectoralis major shadow.
- Ultrasound can determine tear location. Tears demonstrate uneven echogenicity and muscle thinning in comparison with the opposite side.
- MRI can demonstrate the exact location of injury and evaluate partial tears. Must ensure images include sternum (routine "shoulder MRI's" are often localized to shoulder and do not demonstrate the majority of the pectoralis major. (Carrino JA, Skeletal Radiol 2000;29:305)
Pec Rupture Classification / Treatment
- Partial, low grade: sling for comfort, rest and PO pain meds. Begin shoulder mobilization and unresisted stretching exercises when tolerated. Advanced to resisted strengthening exercises at 6 to 8 weeks after injury. Unrestricted activity at 3-4months. High grade partial thickness ruptures should be treated as compete tendon ruptures.
- Complete Sternoclavicular origin: sling for comfort, rest and PO pain meds. Begin shoulder mobilization and unresisted stretching exercises when tolerated. Advanced to resisted strengthening exercises at 6 to 8 weeks after injury. Unrestricted activity at 3-4months.
- Muscle Belly: sling for comfort, rest and PO pain meds. Begin shoulder mobilization and unresisted stretching exercises when tolerated. Advanced to resisted strengthening exercises at 6 to 8 weeks after injury. Unrestricted activity at 3-4months.
- Complete, isolated sternal head tears, or myotendinous junction: Surgical repair indicated. See Pec Repair Technique
- Repairs are ideally done acutely. Delayed repairs still do better than nonsurgical treatment. (Schepsis AA, AJSM 2000;28:9)
- Nonsurgical treatment for complete distal tendon tears is associated with strength deficits and limited return to athletic activity. Pec major function is not necessary for normal shoulder function. Activities involving arm flexion, adduction, and IR may be limited especially with strenuous activity. 51% of pts are satisfied with non-op treatment. (Schepsis AA, AJSM 2000;28:9)
Pec Rupture Associated Injuries / Differential Diagnosis
- Long head of biceps tendon subluxation
- Shoulder dislocation
- Proximal humerus fracture
- Medial Pectoral nerve entrapment: hypertrophied pectoralis minor can cause wasting and weakness of the inferior sternal portion of the pectoralis major.
- RTC tear
Pec Rupture Complications
- Persistent weakness
- Myositis Ossificans
- Shoulder stiffness (abduction)
- Re-rupture / failure
- Continued weakness, Re-rupture, Infection, Neurovascular Injury, Myositis ossificans, Hardware failure, Pain unchanged or worse than before surgery, Stiffness, Incisional scar (cosmesis), CRPS, Numbness surrounding the incision, Need for further surgery, blood clots (DVT), pulmonary embolus (PE), and the Risks of anesthesia including heart attack, stroke and death.
Pec Rupture Follow-up Care
- Post-op: Shoulder immobilizer for 4-6 weeks. Elbow/wrist/hand ROM exercises.
- 7-10 Days: Start pendulum ROM exercises.
- 6 weeks: gentle passive ROM gradually advanced to full ROM and gentle periscapular strengthening started.
- 3 months: ROM should be nearly full and Pectoralis major muscle strengthening is begun.
- 6 months: push-ups and dumbbell bench presses with light weight and high repetition are started.
- 9 to 12 months: return to full-activities. High-weight, low repetition barbell bench pressing is discouraged indefinitely.
Pec Rupture Outcomes
- 88% excellent/good results for surgical repair compared to 27% excellent/good for patients treated non surgically. (Bak K, Knee Surg Sports Traumatol Arthrosc 2000;8:113)
- 99% peak torque, 97% work return after repair; 56% peak torque, 56% work return with conservative treatment. (Hanna CM, Br. J. Sports Med 2001;35:202).
- Subjective ratings: 96% for acute repair, 93% for chronic repair, 51% for nonoperative treatment. (Schepsis AA, AJSM 2000;28:9)
- Isokinetic adduction strength testing: acute repair = 102% of the opposite side; chronic injury repair =94%: non operative treatment=71%. (Schepsis AA, AJSM 2000;28:9). Non-operative treatment leads to adduction and internal rotation weakness and a significant cosmetic defect.
Pec Rupture Review References