Wing scapula syndrome and back pain

Scapular winging syndrome is a rare cause of musculoskeletal pain in the shoulder and posterior chest wall. Caused by paralysis of the serratus anterior muscle, scapular winging syndrome begins as painless weakness in the muscle, followed by the development of a pathognomonic scapular shape.

Muscle pain results from secondary dysfunction due to paralysis of this muscle. At the beginning, scapula winging syndrome is often mistaken for a strain of the muscles of the shoulder group and posterior chest wall, since the onset of the syndrome is often associated with heavy loads, often with carrying a heavy backpack. Tunnel suprascapular neuropathy may coexist.

The development of winged scapula syndrome is often caused by trauma to the long thoracic nerve of Bell. The nerve is formed from the 5th, 6th, 7th cervical nerves, it should be borne in mind the possibility of its damage during stretching and direct injuries. The nerve is also often damaged during resection of the first rib in upper thoracic outlet syndrome. Damage to the brachial plexus or cervical roots can also cause winged scapula, but often in combination with other neurological symptoms.

The pain associated with winged scapula syndrome is aching in nature and is localized in the muscle mass of the posterior chest wall and scapula. The pain may extend to the shoulder and upper arm. The pain is mild to moderate in intensity but can cause significant limitation of function, which, if left untreated, continues to increase the muscular component of the pain.

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Symptoms of winged scapula syndrome

Despite the mechanism of injury to the long thoracic nerve of Bell, a common clinical feature of scapula winging syndrome is scapular paralysis due to weakness of the serratus anterior muscle. Pain typically develops after the onset of sudden muscle weakness but is often incorrectly attributed to strain during overuse. Physical examination reveals limited extension of the last 30 degrees of the upper arm and abnormal scapulohumeral rhythm.

Winged scapulae are easily detected by having the patient press against a wall with outstretched arms behind his back. Other neurological signs should be normal.

Investigation The ambiguity and confusion surrounding the clinical syndrome make it important to perform an investigation to confirm the diagnosis. Electromyography can help differentiate between an isolated lesion of the long thoracic nerve associated with winged scapula syndrome and a brachial radiculopathy. Plain radiography is indicated in all patients with winged scapula syndrome to exclude occult bone pathology. Additional investigations, justified by the clinical picture, may be indicated, including a complete blood count (CBC), uric acid, ESR, and antinuclear antibodies. MRI of the brachial plexus or cervical spinal cord may be indicated if the patient has other neurologic deficits.

Differential Diagnosis Injuries to the cervical spinal cord, brachial plexus, and cervical nerve roots may cause clinical signs that include winged scapula. Such lesions always cause other neurological symptoms, which in any case help the clinician to differentiate such pathological conditions from the isolated clinical signs observed in winged scapula syndrome. Pathology of the scapula or shoulder region may complicate the clinical diagnosis.

Treatment of winged scapula syndrome

There is no specific treatment for winged scapula syndrome other than avoiding the causes of nerve compression (such as carrying heavy backpacks or swelling that compresses the nerve) and wearing orthotics to stabilize the scapula and allow normal shoulder function. Treatment of pain and limitation of function associated with winged scapula syndrome should begin with a combination of NSAIDs (eg, diclofenac, lornoxicam) and physical therapy. Local heat and cold applications may also be effective. Repetitive motions or motions that trigger the syndrome should be avoided.

Side effects and complications

The major complications associated with winged scapula syndrome can be divided into 2 categories: shoulder injury due to limitation of function associated with the syndrome, and failure to recognize that the cause of winged scapula is not an isolated lesion of the long thoracic nerve but another, more significant, neurologic problem.

Scapula winging syndrome is a distinct clinical entity that is difficult to treat. Early removal of the cause of nerve compression should result in restoration of nerve function, resulting in pain relief and restoration of shoulder function. Other possible causes should be thoroughly investigated before attributing neurological symptoms to scapula winging syndrome.