Surgical and Clinical Decision Making in Isolated Long Thoracic Nerve Palsy

Evaluation of the Dysfunctional Scapula

Periscapular pain and dysfunction are relatively common complaints in the practice of upper extremity surgeons. However, evaluation of the dysfunctional scapula is intimidating for most. Physical examination of the periscapular muscles is very rich, and a systematic approach provides the opportunity to establish a diagnosis for most patients. Conditions underlying scapular dysfunction include trapezius palsy, serratus palsy, brachial plexus injuries, muscular dystrophy, snapping scapula, pectoralis minor syndrome, congenital undescended scapula, and functional scapular dyskinesis, among others. Patients should be examined with their torso uncovered and assessed from the front and back. Inspection, evaluation of motion, and strength testing may be followed by certain examination maneuvers specific for each condition. The scapular assistance test may help predict the outcome of treatment for certain conditions. Plain radiographs oftentimes need to be complemented with magnetic resonance of the chest to capture periscapular muscles as well as an electromyogram with nerve conduction studies. Computed tomography is particularly helpful for skeletal abnormalities. Ultrasound is used to assess certain peripheral nerve injuries and to guide diagnostic and therapeutic injections. A focused evaluation of the scapula followed by a more specific and directed approach for each condition suspected will allow upper extremity surgeons to approach the evaluation of the dysfunctional scapula with much more confidence.

Neurolysis of the Long Thoracic Nerve for Scapular Winging due to Isolated Serratus Anterior Palsy: Early and Midterm Results in 29 Patients

Objective

This study aimed to report our surgical outcomes of thoracic long thoracic nerve (LTN) decompression in patients with isolated LTN palsy, using a clinical scoring system designed to facilitate the grading of scapular winging severity.

Methods

This was a retrospective review of patients who had undergone decompression and neurolysis of the LTN for scapular winging. Each patient underwent needle electromyography of the serratus anterior for confirmation of diagnosis and were refractory to a minimum of 6 months of nonoperative management. Preoperatively and at final follow-up, shoulder range of motion and the Wrightington Winging Score (WWS) was used to objectively grade the dynamic and static components of winging.

Results

Between 2014 and 2020, 29 patients who underwent thoracic neurolysis for scapular winging were analyzed. These were 16 males and 13 females with a mean age of 37 years. The injury mechanism was due to trauma in 19 cases and neuralgic amyotrophy in 10. The median duration between winging onset and surgery was 30 months. There were significant improvements in mean active shoulder abduction and forward flexion. Winging was noticeably improved in 22 patients. At presentation, the median WWS was 3, which improved to 1 at final follow-up.

Conclusion

In patients with isolated LTN palsy causing persistent scapular winging which is not responsive to conservative treatment, neurolysis of the thoracic portion of the LTN can be considered.

Level of Evidence

IV.

Thoracodorsal to long thoracic nerve transfer in a patient with traumatic injury: A case report

Background

Traumatic injury to the long thoracic nerve causes paralysis of the serratus muscle, clinically expressed as winged scapula and functional impairment of the shoulder girdle. Treatment varies according to the severity of the injury, with a focus on early intervention for best results; however, the therapeutic approach remains a challenge at present.

Case Description

We present the case of a 32-year-old male patient, athlete, right-handed, presented with bilateral paresis predominantly in the right arm, associated with paresthesia and changes in the coloring of the upper limbs. After being diagnosed with Thoracic Outlet Syndrome and undergoing surgery, vascular symptoms persisted with a significant loss of strength in the right shoulder. Winged scapula was observed and structural lesions were excluded on magnetic resonance imaging. Electromyographic studies confirmed the presumption of traumatic nerve involvement of the long thoracic nerve. Notwithstanding 6 months of physical therapy, there was no improvement, so a nerve transfer from the thoracodorsal nerve to the right long thoracic nerve was chosen. At 12 months, complete resolution of the winged scapula and functional recovery were observed. The patient also experienced a decrease in preoperative pain from 5/10 to 2/10 on the visual analog scale.

Conclusion

Nerve transfer from the thoracodorsal nerve to the long thoracic nerve is a safe and effective technique to treat winged scapula due to long thoracic nerve injury.

Long Thoracic Nerve Palsy: When Is Decompression Indicated

Scapular winging due to long thoracic nerve palsy can occur through traumatic injuries and nontraumatic events. The traditional view is that most patients will achieve spontaneous recovery within 2 years of winging onset. However, there is evidence that points to a less clear-cut natural history, with residual winging, muscle weakness, and fatigability being exhibited in a significant percentage of patients. Reports from proponents of a more proactive approach have shown that the surgical decompression of the long thoracic nerve beyond 12 months, through thoracic, supraclavicular, or combined approaches, can yield satisfactory results. This review examines our current understanding of long thoracic nerve palsy and explores the varying treatment strategies with their reported outcomes.

Neurolysis of the distal segment of the long thoracic nerve for the treatment of scapular winging due to serratus anterior palsy: a continuous series of 73 cases

BACKGROUND

Serratus anterior (SA) palsy following mechanical injury to the long thoracic nerve (LTN) is the most common cause of scapular winging. This study aimed to identify the factors influencing the outcome of neurolysis of the distal segment of the LTN. We hypothesized that poor results are due to duration before surgery and to persistent scapulothoracic dysfunction.

METHODS

A retrospective study was conducted. The inclusion criteria were partial or complete isolated noniatrogenic SA paralysis of at least 4-month duration with preoperative electrophysiologic assessment confirming the neurogenic origin without signs of reinnervation.

RESULTS

Seventy-three patients were assessed at 45 days, 6 months, and 24 months after neurolysis of the distal segment of the LTN. At the last follow-up, improvement was excellent in 38 (52%), good in 22 cases (30%), moderate in 6 (8%), and poor in 7 (10%). No patient showed deterioration in outcomes since the beginning of follow-up. Scapular winging was no longer present in 46 cases (63%), while it was minimal in 23 (31.5%). In 4 cases (5.5%), winging was similar to the preoperative condition.

DISCUSSION

The best outcomes occurred in patients who presented without compensatory muscle pain and who were treated within 12 months of paralysis. Beyond this time frame, neurolysis can still provide useful functional improvement and avoid palliative surgery.

CONCLUSION

Neurolysis of the distal segment of the LTN is a safe and reliable procedure. This technique allows treatment of SA muscle palsy and corrects scapular winging with excellent or good outcomes in 82% of cases.

Scapular winging secondary to serratus anterior dysfunction: analysis of clinical presentations and etiology in a consecutive series of 96 patients

BACKGROUND

This study aimed to establish the relative incidence of etiologies causing serratus anterior (SA) dysfunction in patients with proven abnormality on needle electromyography.

METHODS

This was a retrospective review of patients with scapular winging secondary to SA dysfunction. Each patient underwent a detailed clinical, radiological, and neurophysiological assessment to arrive at the precise etiological diagnosis. Patients with atypical clinical features were referred for a neurologist's assessment. Hematological and genetic testing were requested at the discretion of the neurologist. A scapular winging severity score based on clinical signs was devised to aid clinical grading.

RESULTS

Between 2014 and 2020, a consecutive series of 108 patients with suspected SA dysfunction were assessed, of whom 96 met the inclusion criteria. There were 34 females and 62 males, with a mean age of 38 years (range, 15-77 years). Winging affected the right scapulae in 69 patients, the left scapulae in 17 patients, and was bilateral in 10 patients. This was caused by a myopathic disorder in 12 (12%) patients. Eighty-four (88%) patients had a long thoracic nerve lesion, caused by cervical pathology (2), iatrogenic injury (2), trauma (33), and neuralgic amyotrophy (NA) (47). Among those with NA, winging resolved spontaneously within 3 years of onset in 22 patients (mean duration, 16 months; range, 3-36 months). No patients recovered fully if their duration of winging lasted longer than 3 years. Patients with palsy secondary to NA tended to have a worse severity of winging than those due to a traumatic cause (P = .04).

CONCLUSION

NA accounted for approximately half of the patients with SA dysfunction; therefore, it is essential to also consider the differentials of myopathy, trauma, iatrogenic injury, and spinal pathology. We recommend the judicious employment of ancillary tests and a low threshold of referral to a neurologist, in order to arrive at the exact diagnosis to accurately guide patient treatment.

Scapula alata: diagnosis and treatment by nerve surgery and tendon transfers

Scapula alata, also known as winged scapula, can lead to severe upper limb impairment. The shoulders' function is altered because the scapula, which supports the upper limb, is no longer stable. Typical scapula alata is described for serratus anterior palsy; however, any scapulothoracic muscle impairment may lead to scapular winging, particularly trapezius palsy, which is easy to miss, thus needed to be considered as a differential diagnosis. The diagnosis is difficult and based on various clinical tests and a thorough examination as well as electroneuromyography and MRI. The treatment ranges from conservative treatments for spontaneous recovery, nerve surgery including neurolysis, nerve transfers and nerve grafts for acute cases, to tendon transfers for more chronic cases and when nerve procedures are no longer feasible. Tendon transfers in serratus anterior palsy produce excellent results with a high rate of patient satisfaction and are described with the sternal or clavicular head of the pectoralis major; we describe our preferred technique in this article. Tendon transfers in trapezius palsy are performed with the levator scapulae, rhomboid minor and major muscles. Our preferred method is the Elhassan triple transfer. Scapula alata is a frequent and often misdiagnosed condition. Appropriate management can yield excellent results. Patients should be referred right away to specialized centers for surgery if recovery is not spontaneous.

Nerve transfers in the upper extremity: A review

Injury of the brachial plexus and peripheral nerve often result in significant upper extremity dysfunction and disability. Nerve transfers are replacing other techniques as the gold standard for brachial plexus and other proximal peripheral nerve injuries. These transfers require an intimate knowledge of nerve topography, a technically demanding Intraneural dissection and require extensive physical therapy for retraining. In this review, we present a summary of the most widely accepted nerve transfers in the upper extremity described in the current literature.