Pectoralis major tear in a 23-year-old woman while performing high-intensity interval training: a rare presentation

Abstract

Pectoralis major (PM) tears are a rare injury, that commonly occurs at the sternocostal head and has a greater incidence in men, with only two previously reported cases in young and middle-aged women. The authors report a complete PM tear that occurred in a 23-year-old woman, that presented after performing a ‘muscle-up’. MRI revealed PM rupture at the humeral insertion. Surgical management was performed, and patient returned to high-intensity interval training at 11 months postoperatively and reported great satisfaction. This is the first case in literature that reports a complete tear of the PM in a young woman through an atraumatic mechanism of injury with no previous alteration to the PM. With a cultural increase in wellness, atraumatic PM tear in young women should be expected and remain on the differential for any athlete that participates in high-intensity interval training.

Background

Pectoralis major (PM) tears are an uncommon injury, with less than 400 reported cases in the published literature with 75% of these cases occurring in the last 23 years.^{1 2} The increased incidence of injury has been attributed to the increasing interest in physical health in the general population.^{3 4} Particularly, due to an increase in high impact sports and competitive weight lifting.²

The PM has origins at the clavicle, sternum and ribs, with a common tendon insertion onto the proximal humerus.^5–8 The complex anatomy of the PM allows it to function as a powerful adductor, internal rotator and flexor of the humerus; as well as acting as a stabiliser for the glenohumeral joint.^8–10

Treatment options vary on the type of injury, with tendon rupture at the humeral insertion often requiring surgery, when compared with muscular or myotendinous tendon tears being treated non-surgically.^{7 9} Surgical intervention has been shown to be superior compared with conservative treatment when evaluating for an improvement in function, cosmetic appearance and patient satisfaction.^{8 9} However, patients who are either elderly or not involved in high-intensity demand activities, non-operative management may be ideal.¹⁰

With the literature reporting individual cases of PM tears in male athletes, we present a unique case of a 23-year-old woman who experienced a complete rupture of the left pectoralis tendon sustained from high-intensity interval training while performing a ‘muscle up’, an exercise where the participant begins with the arms in extension over the participant’s head in the resting pull-up position on a bar, transitions into a dip position above the par through a pull-up and completes the exercise with extension of the arm, resulting in the upper body above the bar. When compared with men, literature reports five instances of a PM tear in women, with three cases involving the elderly. To the best of our knowledge, the mechanism of injury in our patient as well as the patient’s young age allows for a unique case presentation.

Case presentation

A 23-year-old woman with no significant medical or surgical history presented with a left shoulder injury that was sustained from high-intensity interval training while performing a ‘muscle up’ at cross-fit, 2 weeks prior to presentation. While in the ‘dip’ position, patient felt a burning and ripping sensation in her axilla and reported pain and weakness afterwards. The next day, patient reported bruising in the area of pain, lack of stability and strength in heavy workouts. She reported significant difficulty in completing the physical demands of her work. Physical examination revealed ecchymosis on the proximal aspect of her left upper arm, mild oedema of chest musculature and classic asymmetry and pain on activation of the left PM muscle. There was pain on palpation of the distal PM tendon. Full forward flexion and elevation were only observed on passive range of motion (ROM). No other musculoskeletal abnormalities were observed on examination, and the patient was neurovascularly intact.

Investigations

MRI showed a complete rupture of the PM tendon at the humeral insertion with retraction medial to the axillary crease, near the deltopectoral interval (figure 1).

Figure 1.

Coronal T2 MRI of the left PM indicates complete rupture at the humeral insertion (*), with retraction medial to the axillary crease, near the deltopectoral interval with comparison of the right PM with no evidence of acute pathology (**). PM, pectoralis major.

Treatment

After imaging findings were reviewed, non-operative management and surgical management were discussed. The patient opted for surgical repair of the left PM tendon given her level of physical activity and findings on MRI.

Surgical Technique

After ensuring safety protocols, the patient was placed in the beach chair position. The left upper extremity was prepped and draped in the usual sterile fashion, and the mechanical arm holder was then applied. Using an incision just medial to the deltopectoral interval, the skin was incised 6 cm in length. The deltopectoral interval was identified as well as the PM tendon, with no significant scarring noted (figure 2). The tendon was retracted medial to the axillary crease. A blunt dissection was done both superficial and deep to the muscle, with great care taken to avoid the lateral pectoral nerve as it exits deep to the PM.

Figure 2.

The pectoralis major tendon tagged intraoperatively (top left) and two drill holes in the humeral footprint (top right). The pectorals major is then cycled down to the footprint with traction on the suture limbs (bottom right).

An Allis clamp was used on the distal stump of the tendon to maintain tension and aid in excursion. Two separate #5 non-absorbable sutures were then used to whipstitch the tendon using a modified Krackow stitch. Once this was completed, appropriate excursion on the tendon was obtained, and we were able to pull the tendon out to the original footprint on the humerus. A blunt Hohmann retractor was used around the lateral aspect of the shaft of the proximal humerus to expose the humeral shaft and footprint. The bony bed was prepared to improve tendon healing to bone. Two drill holes were placed in the footprint (figure 2). Sutures were then passed through two separate metal buttons, which were passed through the unicortical drill holes. The sutures were cycled through the button to pull the tendon back onto the humeral footprint (figure 2). Two tension buttons were flipped once inside the intraosseous position. A single stitch from each arm was then passed through the tendon for backup fixation. The wound was irrigated, passive ROM was appropriate, and without adequate excursion of the repaired tendon without excess tension. The wound was irrigated and cleaned, and standard deep and subcutaneous closure was obtained.

Outcome and follow-up

The patient was discharged and instructed to remain non-weightbearing in the left upper extremity and to use the sling at all times. No pain was reported at 2-weeks follow-up (figure 3). Physical therapy was initiated at 2 weeks for ROM with the patient instructed to remain in the sling outside of physical therapy. ROM at 6 weeks showed forward elevation and abduction to 90° with active external rotation is to about 5° past neutral. Patient was encouraged to use the sling only for her work to avoid the activities of lifting and pulling. At 3-month follow-up, patient reported no difficulty in performing all activities aside from overhead exercises through physical therapy. Physical therapy for strength training was instructed. At 6 months, the patient was then able to perform overhead exercises. Patient was instructed to continue progression with caution, due to full strength return may take up to a year. At the 1-year and 7-month follow-up visit, patient reported returning to high-intensity exercises for the past 8 months, including concentric and eccentric contraction of the PM, but is avoiding the muscle-up exercise for personal preference rather than lack of ability. Physical examination revealed equal strength bilaterally, with the patient reporting great satisfaction with the surgical outcome.

Figure 3.

Postoperative incision at 2 weeks showing appropriate healing.

Discussion

PM tears are rare injuries that have recently seen an increase in frequency. Injuries commonly occur in men between the ages of 20–40 years, with less than five cases being reported in women.^{4 11} Our patient experienced great progression from injury and returned to her normal level of physical activity at 11 months postoperatively. She reported great satisfaction with the surgical outcome. To the best of our knowledge, this is the first case in literature that reports a complete tear of the PM in a young woman through an atraumatic mechanism of injury with no previous alteration to the PM.

With literature reporting predominately men and women older than age of 73 suffering a PM tear, there have been two reported cases occurring in both middle-aged and younger women.^{1 4 11} In one case, a 27-year-old woman suffered a sternal rupture of the PM from traumatic injury. Although in a similar age group to our patient, the patient declined treatment but was referred to a plastic surgeon for cosmetic purposes.¹¹ In a case described by Avery et al, a 49-year-old woman with a medical history of subpectoral breast augmentation reported with a PM tear off the humeral insertion.⁴ Recent literature has shown that that subpectoral breast augmentation may compromise the PM.¹² This further explains the potential differences in injury, given the history of breast augmentation when compared with our patient.⁴

The cultural emphasis on wellness has led to a significant rise in physical fitness in both men and women, which has ultimately shown an increase in musculoskeletal injuries.⁶ A recent systematic review by ElMaraghy et al found 76% (279/365) of PM tears to occur from 1990 to 2010, with a majority of the cases being young and active men.¹

The acute rupture to the PM is often heard by a ‘pop’, during eccentric loading exercises.^{4 8 13} In bench pressing, these injuries occur during eccentric loading of the muscle tendon unit, in transition from eccentric to concentric contraction.2 4–6 8 In a recent study by Godoy et al, 50% of the patients examined experienced PM tear through bench press and 2% through cross-fit, which includes in the high-intensity exercises that our patient participates.⁹ On physical examination, asymmetry of the chest and breast with loss of the axillary fold, swelling, and ecchymosis can be observed.^{4 13} Thinning of the axillary fold, a specific finding for a PM tear can present through abduction of the affected arm.¹³ Weakness with adduction and internal rotation can also be seen.^{4 13}

Further assessment of the injury includes the use of either ultrasound or MRI.^{4 14} The most commonly reported site of injury, seen on imaging is the sternocostal head.^5–7 Although ultrasound can be used for initial screening of injury to evaluate the severity of the PM tear,^{13 14} the use of MRI is preferred in the initial evaluation to prevent misdiagnosis, regardless of injury onset.7 8 13 14 MRI allows for exclusion of other pathologies such as muscle strains and contusions, and a thorough surgical evaluation as is the case of our patient.^{13 14}

The literature has reported improved outcomes and patient satisfaction of surgical management when compared with those treated non-operatively.^{6 14 15} In a case series by Cordasco et al, surgical intervention led to a reported 96% patient satisfaction, 83% ‘good’ restoration of function and adduction strength and a return to sport at an average of 5.5 months.⁸ Both Wolfe et al as well as Hanna et al found that surgical management led to nearly complete recovery of adduction torque when compared with conservative management.^{16 17} Surgical intervention after failed conservative treatment has also reported favourable outcomes in other studies.^{4 18} Therefore, literature has recommended surgical repair in young and active patients, with conservative treatment being reserved for the elderly.^{3 4 13}

Surgical delay more than 8 weeks has been associated with the development of decreased function compared with baseline.^{4 14 19} Regardless of clinical treatment, all patients should be immobilised in an adducted and internally rotated sling in addition to rest to allow for optimal healing and begin restoration of both passive and active ROM prior to surgical intervention.¹³

Aside from literature reporting two case reports of young and middle-aged women, all reported ruptures have been reported in the elderly.^{4 13} In our case, she resumed normal function at 6 months, returned to high-intensity exercises that increase eccentric contraction of the PM at 11 months postoperatively and reported great satisfaction at 1 year and 7 months postoperatively; but is avoiding the muscle-up exercise for personal preference rather than lack of ability. Her frequent high-intensity exercises through cross-fit leads to an increase in eccentric contraction of the PM. With literature suggesting the increasing cultural trend on wellness leading to a significant rise in physical fitness in both men and women; PM tears, a once rare diagnosis in women can be expected and should remain on the differential for any athlete that participates in high-intensity interval training.^{1 3 4}

Learning points.

• This is the first case of a young woman to experience a complete pectoralis major (PM) tear at the humeral insertion through a high-intensity exercise.

• Patient reported great satisfaction and functional outcome at 1-year and 7-month follow-up.

• With a rising trend in wellness, an increased incidence of PM tears in women can be expected.