The Pectoralis major is a very powerful muscle that forms the chest prominence and. It moves the shoulder forwards and across your chest. It is best known as the muscle that you develope with the bench press exercise.
The pec major attaches to the humerus bone (upper bone of arm) and is divided into two parts. The upper part is known as the 'clavicular head' and the lower part the 'sternal head', based on their origins from the clavicle and sternal bones repsectively.
Ruptures of the pectoralis major muscle are becoming more common due to the increase in power sports weight training. It most commonly occurs during bench pressing and is felt as a painful snap at the front of the shoulder and chest. The muscle then 'bunches up' and deforms. Bruising and swelling is common.
Left pec major rupture. Note bruising and asymmetrical chest
Rupture of the sternal and clavicular parts of the Pec Major, with the muscle retracted, giving the 'bunched-up' appearance on the outside
The Pectoralis major may tear/rupture in the following parts of the muscle:
Tear at the junction of the muscle and tendon (musculo-tendinous junction)
Tear within the muscle belly itself
Muscle tearing off the sternum (very rare)
The pec major muscle is not essential for normal daily shoulder function, but is important for srenuous activities. Patients who wish to return to active athletic and manual activities are likely to benefit from surgical repair.
A large statistical review (meta-analysis) of 112 cases of pectoralis major rupture, patients who undergo surgical repair have significantly decreased pain, as well as a higher rate of pre-injury strength and return to activities, than patients managed conservatively [Bak et al.]. Outcome studies comparing conservative with surgical
treatment have demonstrated that surgically repaired injuries regained 97% of the strength of the uninjured arm vs. 56% in non-operative patients [Hanna et al.].
The earlier a repair is performed the easier the surgery and the better the outcome of surgery. Outcomes after early primary repair have generally been superior to those of delayed repair [Aarimaa et al. and Bak et al]. When surgery is delayed, the risk of failure and complications increases as a result of significant scarring and retraction of the muscle. Some of my results were published in 2009 [Shah et al. TSES, 2009].
For delayed and chronic ruptures reconstruction can be considered. This is done using a tendon graft. We have found Achilles tendon Allograft to be the strongest and most reliable tendon graft. For information on tendon allografts click here.
The decision on which pec major tears to repair and when depends on the type of tear, how old it is, how retracted it is, the demands and requirements of the patient and the expertise of the surgeon.
The common types I see are:
Acute (< 3 months)
- tendon avulsion = repair as soon as possible directly to the bone
- Musculo-tendinous tear = I prefer to wait for consolidation of the scar tissue and then reef the muscle-tendon junction with a special high strength suture material that encourages healing (Orthocord). (you cannot repair muscle directly, therefore wait for some fibrous tissue either side of the tear)
- Muscle tear = extremely rare and almost impossible to repair, but can do as above and reinforce with achilles tendon allograft.
Chronic (> approx. 3 months):
- tendon avulsion - if retracted lateral to nippple line usually can still do a direct repair; if retracted medial to nipple line needs a tendo-achilles allograft reconstruction
- Musculo-tendinous & muscle tear - reef repair using high strength biological suture, like a hernia repair.
Outcomes of Surgery:
Based on my experience and audits of our results at 12-18 months post-op, the outcomes of the repairs and reconstructions are: