February 20, 2022

Pectoralis Major Tear

Introduction

Tears of the pectoralis major can occur with weight lifting and may require surgery for full thickness tears. The pectoralis major (PM) muscle originates from the clavicle and sternocostal joint and inserts 4cm distal to the greater tuberosity on the lateral portion of the humerus (1). The action of the PM includes adduction, internal rotation, and forward elevation (1). Injury tends to occur in athletes in their 20s-40s and is typically associated with bench press (1). Wrestling, gymnastics, and football are the sports that see the highest number of PM tears (1). In football, the act of blocking with the arm abducted and externally rotated puts the PM at risk for injury with a sudden eccentric contraction (5). 

Image. Anatomy of pectoralis major (3) 

Diagnosis

The typical history of a PM rupture is a sudden sharp pain in the shoulder sometimes associated with a snap (2). Physical examination findings consistent with an insertional tear are pain to palpation at the insertion on the humeral head and within the patient’s axilla (1). Providers should also evaluate for a sulcus sign at the dectopectoral groove (2). The patient’s shoulder is placed in 90 degrees of abduction and external rotation, which allows for assessment of the pectoralis major tendon within the dectopectoral groove (4). Patients can also be found to have swelling and ecchymosis over the anterior chest and axilla (4). Plain radiographs are typically unremarkable (2).

Image. Physical examination finding for pectoralis major tear (tear demonstrated on the patient’s left side) (3)

MRI and ultrasound can both aid in diagnosis of a muscle belly tear verse an insertional tendon tear (1). Ultrasound findings of an acute tear are hypoechoic hematoma formation and visualization of potential space, suggesting tendon retraction (4). For best visualization of the PM, MRI orders should focus on chest wall sequences and not shoulder sequences (4).

Classification of tears depends on if the anterior or posterior fibers of the PM insertion at torn (6). A full thickness tear involves both anterior and posterior fibers, while a partial tear involves only anterior or posterior fibers (6).

Video. Ultrasound of normal pectoralis in long axis. The probe is moving lateral to medial from the lateral tendon all the way to the sternum.

Video. Ultrasound pec tear in long axis. Look at all the heterogenous muscle fibers and there is a discrete ending of the muscle. 

Treatment

Treatment options depend on the activity level of the individual. More sedentary and older patients will do well with nonoperative treatment of a muscle belly or insertional tendon injury (1). In young and active athletes, surgical repair is typically chosen for complete insertional tears (1). In a comparison of athletes who underwent surgery vs. physical therapy, they found that the nonsurgical group only returned to 56% of their original peak torque strength of the PM (1). In a study looking at NFL players with PM ruptures, it took on average 129 days to recover in both the operative and nonoperative group (5). 

Even chronic tears that occurred greater than six weeks ago can undergo surgical repairs (3). The surgeon will need to debride the scar tissue that has formed during the repair (3). 

Conclusion

Pectoralis Major tears are seen in weight lifters, gymnasts, and football players. A sudden pop in the shoulder during weight lifting or activity suggests a PM tear. MRI or ultrasound can be used to evaluate the tendon insertion. High level athletes should consider surgical repair, while more sedentary individuals may do well with conservative options.

By Gregory Rubin, DO

Rubinsportsmed.com

Read More @ Wiki Sports Medicinehttps://wikism.org/Pectoralis_Major_Injuries

References

1)      Haley, Chad A., and Michael A. Zacchilli. “Pectoralis Major Injuries: Evaluation and Treatment.” Clinics in Sports Medicine, vol. 33, no. 4, Oct. 2014, pp. 739–56. PubMed, https://doi.org/10.1016/j.csm.2014.06.005.

2)      Quinlan, J. F., et al. “Pectoralis Major Tendon Ruptures: When to Operate.” British Journal of Sports Medicine, vol. 36, no. 3, June 2002, pp. 226–28. PubMed, https://doi.org/10.1136/bjsm.36.3.226.

3)      Petilon, Julio, et al. “Pectoralis Major Muscle Injuries: Evaluation and Management.” The Journal of the American Academy of Orthopaedic Surgeons, vol. 13, no. 1, Feb. 2005, pp. 59–68. PubMed, https://doi.org/10.5435/00124635-200501000-00008.

4)      Kowalczuk, Marcin, and Amr Elmaraghy. “Pectoralis Major Rupture: Evaluation and Management.” The Journal of the American Academy of Orthopaedic Surgeons, Jan. 2022. PubMed, https://doi.org/10.5435/JAAOS-D-21-00541.

5)      Sahota, Shawn, et al. “Pectoralis Major Injuries in the National Football League.” Sports Health, vol. 12, no. 2, Apr. 2020, pp. 116–23. PubMed, https://doi.org/10.1177/1941738119885867.

 

6)      Chiavaras, Mary M., et al. “Pectoralis Major Tears: Anatomy, Classification, and Diagnosis with Ultrasound and MR Imaging.” Skeletal Radiology, vol. 44, no. 2, Feb. 2015, pp. 157–64. PubMed, https://doi.org/10.1007/s00256-014-1990-7.