Pectoralis Major Rupture

The Problem

Pectoralis major tendon ruptures are relatively uncommon. The injury tends to occur almost exclusively in men and usually affects the 20-40 year age group. There is also a subset of the elderly population that sustain ruptures to the pectoralis major tendon. Ruptures of the tendon can cause significant pain, weakness, and deformity. Surgical treatment is often recommended, preferably within the first several weeks after the injury, in order to restore function, strength, and cosmesis to the upper extremity.

Clinical Presentation

Pectoralis major tendon ruptures typically occur during weight training, weight lifting, or wrestling when the arm is externally rotated and abducted. In weight lifters, the most common cause of rupture is the bench press.

The pectoralis major is at risk during any activity in which the arm is extended and externally rotated while under maximal contraction. Rupture is classically followed by a tearing sensation, an audible pop, immediate pain, and weakness. Bruising and ecchymosis may follow in the subsequent days.

The classic history of a pectoralis major tendon rupture is a 20-40 year-old male weight-lifter who injures his chest and shoulder during a bench press. Other activities include windsurfing, wrestling, gymnastics, rugby, and football. There may or may not be a history of anabolic steroid use.

Diagnostic Workup

Classic physical exam findings include swelling and ecchymosis in the anterior shoulder and arm region, especially around the tendon insertion on the humerus. Ecchymosis, caused by bleeding from the muscle, can be extensive and track down the tissue planes into the lower arm and torso. Close inspection reveals asymmetry of the axillary folds, with deficiency on the injured side. This deficiency can be further elucidated by having the patient push their palms together in front of their body (isometric contraction of the pectoralis major). A palpable defect is often detected with associated weakness of internal rotation.

Plain radiographs of the shoulder are often non-contributory unless bone is avulsed from the humerus.

Ultrasound is an inexpensive and effective modality to identify a pectoralis major rupture. It may be useful to compare anatomy on ultrasound with the contralateral/unaffected side.

Magnetic resonance imaging (MRI) is the imaging modality of choice for pectoralis tendon ruptures. A traditional MRI of the shoulder will often miss a pectoralis tendon rupture because the imaging does not travel far enough down on the humerus. A MRI of the chest or a MRI of the shoulder with distal extension down the humerus must therefore be ordered in order to adequately image the tendon. The MRI can also help demonstrate whether the patient sustained a partial versus full rupture of the tendon, whether the injury is acute versus chronic, and the extent of tendon retraction in the setting of a complete rupture.

Non–Operative Management

Non-operative treatment is typically reserved for elderly or low-demand patients. In most cases, young males who are active in weight-lifting cannot be treated with non-operative treatment and surgical repair is indicated. Partial tendon ruptures and ruptures of the muscle belly can also be considered for non-operative treatment.

Non-operative treatment includes rest, analgesic medication, cold compression, and sling immobilization in the adducted and internally rotated position. Passive and active range of motion exercises as well as pendulums can typically be started 1-2 weeks after the injury and should be continued for 6 weeks. If after 6 weeks, there is adequate pain control and range of motion, resistance exercises can be started and should continue until the patient achieves unrestricted motion and strength. Only one in four patients report excellent results with non-operative treatment. While strength can often be restored to near-normal, cosmetic deformity often persists and patients cannot often return to competitive sport or weight-lifting.

Indications for Surgery

Indication for surgery is a young and active patient who participates in sport or weight-lifting who sustains a pectoralis major tendon rupture. Even though the pectoralis major is not required for activities of daily living, patients who participate in sport or weight-lifting are clear indications for tendon repair, regardless of the chronicity of the injury. Results for patients who had anatomic repairs within 8 weeks of the injury show increased success compared to later surgical interventions for chronic injury.

Surgical Technique

The surgical technique involves an open repair. Arthroscopic techniques/equipment are unnecessary unless there is a concomitant injury to the shoulder joint that requires surgical repair.

Positioning can be either in the beach-chair or supine position. If the beach-chair position is used, a captain’s chair should be requested.

Both deltopectoral and anterior axillary approaches have been used. In the deltopectoral approach, the proximal portion of the incision should be more medial relative to the more lateral distal portion.

Different methods have been described to repair the avulsed pectoralis tendon to the humeral bone. The use of sutures with drill holes and suture anchors are the most common methods of repair. If bone tunnels are used, creating a trough has been shown to provide the greatest amount of tension support. Most recently, a repair technique using a unicortical button type device has been described.

If suture anchors are used, consider metal or PEEK type anchors because of their increased strength compared to bioabsorbable anchors, since the cortical bone of the humerus is extremely strong. Multiple anchors are often necessary to restore the total footprint of the pectoralis major tendon insertion on the humerus. Mason-Allen or Krakow type stitches should be used to obtain good secure fixation of the sutures in the tendon.

If drill holes are used, multiple bone tunnels are created with a 2.0 mm drill. A trough can be created at the insertion of the tendon at the lateral lip of the bicipital groove to allow for more tension support and more contact between the tendon and bleeding bone. If planning a trough, a motorized burr is necessary. A free needle will then be used to pass the sutures from the tendon through the bone tunnels.

If a chronic rupture is indicated for repair, we recommend requesting an allograft before surgery in case the tendon needs to be augmented or in case the tendon cannot be adequately mobilized for repair back to the humerus. Fortunately, even in chronic cases, allograft is normally not required. My preference is an Achilles tendon allograft because of the wide surface area of the allograft tendon.

For musculotendinous, muscle belly, and tendon intrasubstance ruptures, a No. 2 non-absorbable braided suture can be used in a mattress fashion to reapproximate the two ends.

For bony avulsions, successful repair can be accomplished by removing the bony avulsion and performing a classic drill-hole or suture anchor repair or by using a screw and washer if the bony avulsion is large enough, in order to secure the bony fragment to its original site.

I prefer to set up the patient in a beach-chair position with a captain’s chair and drape the affected extremity free to allow for increased visualization during the surgery. Regional anesthesia is preferred and may be combined with general anesthesia. The head is securely padded for the case.

After typically prepping and draping, I use an anterior axillary incision, following the natural creases of the axilla. Once the skin and subcutenous tissues are exposed, I locate the deltopectoral fascia and the cephalic vein. Typically, there is a rent in the muscle and fascia at the location of the defect at the axillary fold. With finger dissection, the rent can be explored and the ruptured tendon can be identified and retrieved. Suction is used to evacuate the hematoma. Once the ruptured tendon is exposed, three sets of No. 5 non-absorbable sutures are passed through the tendon in a Mason-Allen configuration. These three sets of sutures are then clamped as I expose the humeral insertion of the pectoralis major tendon.

The long head of the biceps and bicipital groove are then identified with retractors. The biceps tendon is retracted medially during the procedure so that we do not mistakenly repair the pectoralis with the biceps out of the groove. After removing the remains of the pectoralis tendon soft tissue from its insertion on the humerus, a 2.0 mm drill is used to create four bone tunnels on the lateral lip of the bicipital groove of the humerus. I use a high-speed burr to create a trough for the tendon at the humeral insertion site. Once the bone tunnels are created, I use a free needle to pass four passing sutures through the four bone tunnels. The three sets of sutures that have been secured to the tendon are then passed through the four bone tunnels using the passing sutures. Knots are securely tied with the arm in adduction and internal rotation. The biceps tendon is then checked to ensure that it is back in the groove and not trapped by the pectoralis tendon repair.

If suture anchors are used, three 4.5 or 5.5 suture anchors are punched, tapped, and inserted into the humerus. One set of suture from each anchor is then secured into the ruptured tendon using a Krakow or Mason-Allen suture configuration. The free end of the suture is then pulled through the anchor to reduce the tendon to the humerus. Knots are tied securely with the arm in adduction and internal rotation.

Pearls and Pitfalls of Technique

Pearls

• Whether a deltopectoral or anterior axillary approach is used, cheat the incision distal and medial toward the axilla for best exposure.

• Typically the bone of the humerus is extremely strong. A small drill may be considered for use before the punch and tap for the suture anchor to allow for easier insertion of the anchor.

• The axillary incision is very amenable to a subcuticular closure for improved cosmesis.

Pitfalls

• The proximity of the biceps tendon to the pectoralis major insertion can lead to iatrogenic damage to the biceps or to entrapment of the biceps outside the bicipital groove during repair if it is not clearly retracted medially during the case.

• The cephalic vein should be identified if possible, especially if the traditional deltopectoral approach is used. Injury to the cephalic vein can potentially lead to increased post-operative swelling of the operative extremity.

• Because the pectoralis tendon has a relatively broad insertion, multiple suture anchors and multiple drill-holes should be used to re-approximate the footprint of the tendon insertion. If only one or two anchors or drill holes are used for fixation, repair and eventual strength of the repair may be inadequate and there may be an increased risk of re-rupture.

Potential Complications

Post-operative infection is the most concerning post-operative complication. The axillary area lends itself to bacteria and because of the moisture in this area, there may be an increased risk of infection. Careful handling of the soft tissues, antibiotic prophylaxis, and meticulous closure can decrease the chances of this complication. Re-rupture of the tendon after repair has also been described. Please refer to the pearls and pitfalls section for recommendations on how to reduce this complication. Heterotopic ossification and hematoma requiring evacuation have also been described. Injuries to the medial and lateral pectoral nerves are possible during repair. However, such injuries are extremely rare. Injuries to the long head of the biceps tendon have also been described and discussed above.

Post–operative Rehabilitation

Post-operatively, the arm is placed in an immobilizer or sling that keeps the arm in internal rotation and adduction for 4-6 weeks. Gentle range of motion shoulder exercises are initiated after 2 weeks. After 4-6 weeks, the sling is removed and full range of motion is obtained with physical therapy. Resistive range of motion exercises and strengthening exercises are begun at approximately 8 weeks or after full range of motion is achieved. Full recovery and return to sport with weight-lifting usually takes 3-6 months, depending on the type of sport, the severity of the injury, and security of the repair.

Outcomes/Evidence in the Literature

Metzger, PD, Bailey, JR, Filler, RD, Waltz, RA, Provencher, MT, Dewing, CM. “Pectoralis major muscle rupture repair: technique using unicortical buttons”. Arthrosc Tech. vol. 1. 2012. pp. e119-25. (This study described a novel technique for surgical repair of the pectoralis tendon. A unicortical suture button is used and the technique achieves the goals of strong fixation and anatomic fixation of the tendon back to its footprint.)

Michael A, MA, Fowler, JT, Owens, BD. “Allograft reconstruction of chronic pectoralis major tendon ruptures”. J Surg Orthop Adv. vol. 22. 2013. pp. 95-102. (Three military patients underwent chronic pectoralis major tendon reconstructions using Achilles tendon allograft. All patients were satisfied.)

Wheat Hozack, MJ, Bugg, B, Lemay, K, Reed, J. “Tears of pectoralis major in steer wrestlers: a novel repair technique using the Endobutton”. Clin J Sport Med. vol. 23. 2013. pp. 80-2. (Case report describing the novel use of an endobutton device as intramedullary fixation for a pectoralis major tendon repair.)

Sherman, SL, Lin, EC, Verman, NN, Mather, RC, Gregory, JM, Dishkin, J, Harwood, DP, Wang, VM, Shewman, EF, Cole, BK, Romeo, AA. “Biomechanical analysis of the pectoralis major tendon and comparison of techniques for tendo-osseous repair”. Am J Sports Med. vol. 40. 2012. pp. 1887-94. (Biomechanical cadaveric study looking at twenty-four shoulders randomized to four groups. Transosseous repair, suture anchors, and Pec Button repair were all inferior to the native pectoralis tendon. No significant difference in outcomes amongst the repair groups.)

Rabuck, SJ, Lynch, JL, Guo, X, Zhang, LQ, Edwards, SL, Nuber, GW, Saltzman, MD. “Biomechanical comparison of 3 methods to repair pectoralis major ruptures”. Am J Sports Med. vol. 40. 2012. pp. 1635-40. (Thirty cadaveric shoulders split evenly into three groups: bone trough, cortical button, and suture anchor repairs. Bone trough repair was found to be stronger than suture anchor repair.)

Provencher, CMT, Handfield, K, Boniquit, NT, Reiff, SN, Sekiya, JK, Romeo, AA. “Injuries to the Pectoralis Major Muscle: Diagnosis and Management”. Am J Sports Med. vol. 38. 2010. pp. 1693-1705. (An overview and review paper looking at diagnosis and management of pectoralis major tendon ruptures.)

El Maraghy, AW, Devereaux, MW. “A systematic review and comprehensive classification of pectoralis major tears”. J Shoulder Elbow Surg. vol. 21. 2012. pp. 412-22. (The authors proposed a contemporary injury classification system that includes injury timing (acute vs. chronic), injury location (muscle origin or belly, at or between the musculotendinous junction and the tendinous insertion, or bony avulsion), and standardized terminology addressing tear extent (anterior-to-posterior thickness and complete vs. incomplete width).)

Hart, ND, Lindsey, DP, McAdams, TR. “Pectoralis major tendon rupture: a biomechanical analysis of repair techniques”. J Orthop Res. vol. 29911. 2011. pp. 1783-7. (Twelve cadaveric shoulders divided between transosseous trough with suture tied over bone vs. four suture anchors. No statistical difference between the two repair techniques.)

de Castri Pochini, A, Ejnisman, B, Andreoli, CV, Monteiro, GC, Silva, AC, Cohen, M, Albertoni, WM. “Pectoralis major muscle rupture in athletes; a prospective study”. Am J Sports Med. vol. 38. 2010. pp. 92-8. (Twenty athletes with tendon rupture were studied. Ten were treated non-operatively, ten with surgery. Patients who underwent surgery had a better outcome.)

Ho, LC, Chiang, CK, Huang, JW, Hung, KY, Wu, KD. “Rupture of pectoralis major muscle in an elderly patient receiving long-term hemodialysis: case report and literature review”. Clin Nephrol. vol. 71. 2009. pp. 451-3. (Case report of a pectoralis major rupture in an elderly patient receiving hemodialysis.)

Summary

Pectoralis major tendon rupture, while uncommon, typically occurs in males age 20-40 who injure themselves while weight-lifting, especially with the bench press exercise. Pain, weakness, loss of the axillary fold, and ecchymosis can occur. Magnetic resonance imaging is the best imaging modality to diagnosis rupture of the pectoralis major tendon. Ultrasound is also useful and less expensive. Non-operative treatment is typically reserved for the elderly population. Surgical treatment offers the best results in the young and active population, especially if they participate in sport or weight-lifting.

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