Long thoracic nerve palsy is a shoulder condition characterized by pain and loss of shoulder movement owing to damage or injury of the long thoracic nerve. This nerve evolves from the roots of neck vertebrae (C5-C7) and supplies to serratus anterior muscle that retains the scapula bone to the chest wall. Serratus anterior muscle is also involved in forward arm activities such as boxing, and in overhead activities.
Damage of the long thoracic nerve may result in abnormal protruding of the scapula or shoulder blade, commonly known as winged scapula. Moreover, long thoracic nerve may be linked with parsonage-turner syndrome, a condition that is caused due to its inflammation or immune-mediated pathway.
Long thoracic nerve is more prone to injury due to its excessive length. Usually, injury to this nerve occurs due to trauma, direct blow to the rib area, over stretching or strenuous repetitive movements of the arms, and sustained bearing of excessive weight over the shoulder. Moreover, surgical procedures such as radical mastectomies and deep tissue massage may even cause long thoracic nerve injury.
The major symptoms associated with long thoracic nerve palsy, include:
- Shoulder pain
- Winged scapula
- Reduced overhead activity
The diagnosis of long thoracic nerve palsy involves medical history, physical examination and various diagnostic imaging techniques such as electromyography (EMG), nerve conduction velocity test, and MRI scan, as confirmatory measures
The treatment of long thoracic nerve palsy depends upon the level of nerve damage that may range from acute injury to severe damage. The treatment options include physical or occupational therapy, and surgery. Surgery involves repair of the nerve either directly or with grafts and one of the widely employed surgical procedures is scapulothoracic fusion. Usually recovery of the nerve takes a long time; up to 6 months.
Scapulothoracic (ST) fusion is a salvage procedure performed to stabilize the scapula on the thorax. It involves the fusion of the medial border of the scapula to the underlying 3 to 5 ribs. The scapulothoracic (ST) motion plays an important role in shoulder elevation and abduction. This procedure is recommended when tendon transfer fails to treat spinal accessory nerve palsy and long thoracic nerve palsy. Other conditions that can be treated through scapulothoracic fusion include facioscapulohumeral dystrophy, medial clavicular insufficiency and brachial plexus.
The basic steps involved in scapulothoracic fusion surgery include:
- Patient is laid on the operation table with face down and is anesthetized under general anesthesia
- An incision is made along medial border of scapula
- Then inner margin of the scapula bone along its full length is exposed along with underlying 3 to 5 ribs
- Then scapula is wired to the adjacent ribs
- Bone graft is placed at the contact point and also bone stimulator is implanted to promote fusion
- Finally incision is closed
Usually the whole procedure takes 3-4 hours and patient may require staying in hospital for 3-5 days.
The patients who have undergone scapulothoracic fusion are advised to follow some basic instructions:
- Wear sling and avoid use of operated extremity first 6 weeks
- Follow your therapists instructions regarding activity and exercise during healing process
It may take 6 months or up to 1 year for full functioning of the shoulder.
Risks and complications
Although scapulothoracic fusion is a safe procedure, various risks and complications have been reported that include:
- Metalwork failure
- Adhesive capsulitis
- Nonunion of bone
- Pleural effusion
- Thoracic outlet syndrome
- Scapula fracture
- Deep venous thrombosi