The subscapularis muscle is a critical part of the rotator cuff, located at the front of the shoulder. Its role is to rotate the arm inward and stabilize the shoulder joint. When this tendon is torn and cannot be repaired due to muscle retraction or degeneration, it can lead to pain, weakness, and shoulder instability. This condition is particularly disabling because the subscapularis is the only muscle providing support at the front of the shoulder.
How Common It Is and Who Gets It? (Epidemiology)
Tears of the subscapularis tendon are relatively uncommon but can be severely debilitating, especially in active individuals. It often occurs due to trauma, chronic degeneration, or as part of larger rotator cuff tears. It is more common in patients over the age of 40, especially those who have engaged in repetitive overhead activities or have experienced prior shoulder injuries. The pectoralis major tendon transfer is typically considered for patients who have persistent shoulder dysfunction due to an irreparable subscapularis tear, especially when they are younger and more active.
Why It Happens – Causes (Etiology and Pathophysiology)
The subscapularis tendon can become damaged through acute trauma, repetitive stress, or degenerative changes. In older patients, it may tear as a result of chronic shoulder instability or wear and tear. In younger patients, traumatic injuries like falls or sports-related injuries are often the cause. When the tendon is torn, especially with significant muscle retraction or degeneration, repairing it directly may not be possible, and tendon transfer becomes the next best option to restore shoulder stability and function.
How the Body Part Normally Works? (Relevant Anatomy)
The subscapularis is the largest muscle of the rotator cuff and plays a vital role in shoulder function. It enables internal rotation of the arm and helps stabilize the shoulder joint by keeping the humeral head (the ball of the shoulder) centered in the glenoid (shoulder socket). This muscle is essential for movements such as lifting, throwing, and pushing, making it critical for upper limb strength and shoulder stability.
What You Might Feel – Symptoms (Clinical Presentation)
Patients with a torn subscapularis tendon often experience:
- Shoulder pain, especially when attempting overhead activities or lifting objects
- Weakness in the shoulder, particularly when trying to rotate the arm inward or perform pushing movements
- Instability or a sense that the shoulder is “giving way” during certain motions
- Limited range of motion, especially in internal rotation and lifting the arm overhead
- The “hornblower sign,” which indicates weakness in the teres minor muscle, a secondary muscle contributing to shoulder rotation
How Doctors Find the Problem? (Diagnosis and Imaging)
Diagnosis begins with a physical examination to assess shoulder strength, range of motion, and specific tests to identify subscapularis dysfunction, such as the lift-off or belly press test. Imaging studies such as MRI or CT arthrograms are used to visualize the tear and determine the extent of muscle retraction and degeneration. MRI can also help rule out other rotator cuff injuries and provide a detailed assessment of the surrounding tissues.
Classification
Subscapularis tears are often classified by their size and severity:
- Partial-thickness tears: Involves a tear of only part of the tendon.
- Full-thickness tears: Complete disruption of the tendon.
- Massive tears: Large tears that involve significant retraction and degeneration of the tendon, often requiring tendon transfer.
Other Problems That Can Feel Similar (Differential Diagnosis)
Conditions that may mimic the symptoms of subscapularis tears include other rotator cuff tears (e.g., supraspinatus or infraspinatus tears), shoulder instability, acromioclavicular joint arthritis, and labral tears. Proper diagnosis is essential to differentiate between these conditions and ensure appropriate treatment.
Treatment Options
Non-Surgical Care
- Rest and activity modification to prevent further strain on the shoulder
- Anti-inflammatory medications and corticosteroid injections to reduce pain and inflammation
- Physical therapy to strengthen the remaining rotator cuff muscles and improve shoulder stability
Surgical Care
- Pectoralis major tendon transfer: When the subscapularis tendon is irreparable, part of the pectoralis major tendon is transferred to the shoulder to restore function. This procedure is often considered for active individuals who have failed conservative treatment or prior rotator cuff repairs.
Recovery and What to Expect After Treatment
After pectoralis major tendon transfer surgery:
- Initial recovery: The shoulder is immobilized in a sling for 4–6 weeks to allow for initial healing. Passive range-of-motion exercises are started early to prevent stiffness.
- Rehabilitation: Active exercises begin gradually, starting around 6 weeks, with the focus shifting to strengthening the shoulder muscles and restoring function.
- Full recovery: Most patients return to normal activities and sports after 6–12 months, depending on the severity of the injury and rehabilitation progress.
Possible Risks or Side Effects (Complications)
Complications from pectoralis major tendon transfer are relatively rare but can include:
- Failure of the tendon to heal or re-rupture
- Infection at the surgical site
- Nerve injury, particularly to the musculocutaneous nerve
- Persistent weakness or limited range of motion
- Hardware irritation (in cases where screws or anchors are used for fixation)
Long-Term Outlook (Prognosis)
The long-term prognosis for patients undergoing pectoralis major tendon transfer is generally favorable, especially for those with isolated subscapularis tears. The procedure can significantly improve shoulder strength and reduce pain, allowing many patients to return to normal activities and sports. However, outcomes may be less predictable for patients with additional rotator cuff damage or those who have had previous failed repairs.
Out-of-Pocket Cost
Medicare
CPT Code 23395 – Pectoralis Major Tendon Transfer (Surgical Transfer of the Pectoralis Major Tendon for Shoulder Function Restoration): $304.12
Medicare Part B typically covers 80% of the approved cost for this procedure once your annual deductible has been met, leaving you responsible for the remaining 20%. Supplemental Insurance plans such as Medigap, AARP, or Blue Cross Blue Shield usually cover that remaining 20%, significantly reducing or eliminating out-of-pocket expenses for Medicare-approved surgeries. These plans work in coordination with Medicare to fill the coverage gap and reduce patient costs.
If you have Secondary Insurance, such as TRICARE, an Employer-Based Plan, or Veterans Health Administration coverage, it acts as a secondary payer. These plans generally cover any remaining balance, including coinsurance or small deductibles, which generally range between $100 and $300, depending on your plan and provider network.
Workers’ Compensation
If your pectoralis major tendon transfer is required due to a work-related injury, Workers’ Compensation will cover all associated medical expenses, including surgery, rehabilitation, and follow-up care. You will not have any out-of-pocket expenses, as the employer’s insurance carrier directly covers all approved treatments.
No-Fault Insurance
If your pectoralis tendon transfer surgery is needed due to an automobile accident, No-Fault Insurance will typically cover the full cost of treatment, including surgery and postoperative care. The only potential out-of-pocket cost may be a small deductible or co-payment depending on your insurance policy.
Example
Mark Stevens underwent a pectoralis major tendon transfer (CPT 23395) to restore shoulder function after a traumatic injury. His estimated Medicare out-of-pocket cost was $304.12. Since Mark had supplemental insurance through AARP Medigap, his remaining balance was fully covered, leaving him with no out-of-pocket expenses for the procedure.
Frequently Asked Questions (FAQ)
Q. What is a pectoralis major tendon transfer?
A. It is a surgical procedure where the pectoralis major tendon is moved to a different location to compensate for loss of shoulder function, often due to irreparable rotator cuff tears.
Q. When is a pectoralis major tendon transfer typically performed?
A. It is usually performed in cases where the rotator cuff is irreparably torn and shoulder function, particularly internal rotation and forward elevation, is significantly compromised.
Q. What symptoms might lead to the consideration of a pectoralis major tendon transfer?
A. Symptoms include weakness, limited shoulder mobility, and an inability to lift the arm or perform activities of daily living due to rotator cuff insufficiency.
Q. Who is a good candidate for a pectoralis major tendon transfer?
A. Patients with an irreparable subscapularis tear and minimal glenohumeral arthritis, but who retain an intact deltoid muscle and sufficient shoulder motion, are good candidates.
Q. What does the pectoralis major muscle do?
A. The pectoralis major muscle helps with internal rotation, flexion, and adduction of the shoulder.
Q. How does transferring the pectoralis major tendon help?
A. The transfer compensates for lost subscapularis function by restoring the ability to internally rotate and stabilize the shoulder.
Q. How is the pectoralis major tendon transfer performed?
A. The tendon is detached from its usual insertion and reattached to the humerus in a location that mimics the original function of the damaged subscapularis tendon.
Q. Is general anesthesia required for a pectoralis major tendon transfer?
A. Yes, the procedure is typically performed under general anesthesia.
Q. What is the expected recovery time after surgery?
A. Recovery can take several months, including immobilization followed by a structured physical therapy program.
Q. What are the risks of pectoralis major tendon transfer surgery?
A. Risks include infection, nerve injury, re-tear of the transferred tendon, stiffness, or failure to restore desired function.
Q. Will physical therapy be needed after surgery?
A. Yes, physical therapy is essential for regaining strength and range of motion following the procedure.
Q. What type of incision is made for this procedure?
A. An incision is made near the shoulder to access and mobilize the pectoralis major tendon.
Q. Can the procedure restore full shoulder function?
A. While it may not fully restore normal function, the surgery can significantly improve strength and allow for better performance of daily activities.
Q. How successful is a pectoralis major tendon transfer?
A. When appropriately indicated, the procedure has shown good outcomes in improving shoulder function and reducing pain.
Q. Are there non-surgical alternatives to this procedure?
A. Non-surgical options include physical therapy, injections, and activity modification, but they may not be effective for irreparable tendon tears.
Summary and Takeaway
Pectoralis major tendon transfer is an effective surgical option for patients with irreparable subscapularis tears. By using a nearby muscle to restore shoulder function, this procedure offers pain relief, improved shoulder stability, and a good quality of life for active individuals. Advances in surgical techniques, such as using a small piece of bone with the tendon, have improved outcomes and reduced the risk of complications.
Clinical Insight & Recent Findings
A recent study compared the clinical outcomes of split pectoralis major tendon (PMT) transfer with Achilles allograft for the treatment of chronic medial scapular winging due to long thoracic nerve injury.
The study found that this technique was effective in significantly improving both pain and functional outcomes. Patients demonstrated improvements in shoulder range of motion, with a notable reduction in pain and a high rate of patient satisfaction—80% would recommend the procedure. However, some complications were reported, including graft failure and mild cosmetic deformities, but these were rare.
The technique, which uses a split tendon along with an allograft to restore shoulder stability, was found to have a low complication rate compared to other treatments like scapulothoracic fusion. These results highlight the potential of this technique to provide a reliable solution for patients with severe scapular winging. (“Study on split pectoralis major tendon transfer – see PubMed.“)
Who Performs This Treatment? (Specialists and Team Involved)
Orthopedic surgeons specializing in shoulder reconstruction and tendon transfers typically perform this procedure. Rehabilitation is supervised by physical therapists to help restore shoulder function and strength.
When to See a Specialist?
Consult a specialist if you experience persistent shoulder pain, weakness, or instability that limits your ability to perform daily tasks or activities.
When to Go to the Emergency Room?
Seek emergency care if you experience severe pain, significant weakness, or if the shoulder appears deformed following an injury.
What Recovery Really Looks Like?
Recovery involves initial immobilization followed by gradual physical therapy to restore shoulder motion and strength. Full recovery may take several months, depending on the severity of the injury.
What Happens If You Ignore It?
If left untreated, irreparable subscapularis tears can lead to persistent shoulder pain, instability, and long-term dysfunction, often requiring more invasive treatments like shoulder replacements.
How to Prevent It?
Preventing subscapularis tears involves strengthening the shoulder muscles, using proper technique during physical activities, and avoiding excessive strain on the shoulder joint.
Nutrition and Bone or Joint Health
A diet rich in calcium, vitamin D, and omega-3 fatty acids supports joint and muscle health, aiding in recovery and long-term function.
Activity and Lifestyle Modifications
Avoiding repetitive overhead lifting and strengthening the shoulder muscles can help prevent future injuries and improve long-term shoulder health.
