What is the pathology of a pectoralis major tendon tear?
Healthy tendons rarely tear. A pectoralis major tendon tear occurs when a tendon weakened by wear and tear in the tendon is overloaded. The use of anabolic steroids is considered to be a risk factor. The commonest site of rupture is where the tendon attached to bone. In rare instances the tear may occur at the junction between the muscle and tendon.
Partial tear: A partial tear may affect the tendon of the clavicular part of the muscle.
Complete tear: When the tendon is completely torn the tendon gets pulled up by the muscle and shape of the muscle changes.
How is a pectoralis major tendon tear diagnosed?
A diagnosis of pectoralis major tendon tear is made based on the history of sudden pain and a ripping or snapping sensation on the front of the shoulder whilst lifting a heavy object. Individuals who train in the gym may suffer a tear when performing bench presses. The injury may be associated with a feeling of weakness. Examination shows a change in the contour of the pectoralis major muscle with asymmetry between the two sides and often a drop in the level of the nipple. There may be some bruising on the front of the chest wall extending to the armpit. The fold at the front of the armpit may feel thinner than the other side. An ultrasound or MRI scan may be requested to confirm the diagnosis.
What is the treatment for a pectoralis major tendon tear?
In the early phase, pain may be controlled with the use of pain relieving or anti-inflammatory medication.
In low-demand individuals, or those with partial tears, the injury may be treated initially with activity modification, protection and physiotherapy. Less active individuals with complete tears may choose not to have surgery for this injury. Pain usually settles fairly quickly but individuals may experience some weakness of the arm or aching particularly with strenuous activities. A cosmetic deformity of the chest wall may persist.
Most active individuals with complete tears of the pectoralis major tendon will be offered the choice of having the tendon repaired surgically. The operation is best performed within the first 2-3 weeks after the injury. Outcomes are generally good when the tendon has torn close to the bone. Surgical repair is more challenging in instances where the tear has occurred at the muscle-tendon junction. For further information on surgical treatment, please refer to the section on “Pectoralis major tendon repair” overleaf.