Excellent Recovery of Shoulder Movements After Decompression and Neurolysis of Long Thoracic Nerve in Teen Patients With Winging Scapula

Long thoracic nerve (LTN) injury is a rare and misdiagnosed painful condition that causes scapular instability and loss of upper extremity movements and function in some patients. Scapular winging results from nerve damage to the LTN, spinal accessory nerve, or, less commonly, the dorsal scapular nerve. C5-C7 brachial plexus preganglionic injuries are also associated with complete paralysis of the LTN.¹ Several athletic activities are known to cause injury to LTN.²

Most of our teen patients in this study had sports-related injuries, because of overuse and practicing poor sports technique,³ as well as accidents. Moreover, they are skeletally immature.³ As the LTN passes along the thorax, it can be compressed by blood vessels and/or fibrotic tissue.⁴ Although some investigators have recommended conservative treatment of this condition,⁵ often timely surgical treatment⁶ is vital to the recovery of scapular winging secondary to LTN palsy.⁷ Recently, we have analyzed and compared the effectiveness of muscle and tendon operative procedures to decompression and neurolysis of LTN and demonstrated that LTN decompression is an easy and effective treatment to correct winging scapula.⁸ Here, we report a significant improvement in scapula winging and active range of motion (AROM) of the shoulder in 16 teen patients after LTN decompression and neurolysis.

Of 555 patients who visited our clinic with winging scapula since 2005, 16 teenage patients met the inclusion criteria of this study.

Exclusion criteria

  1. Teen patients who had LTN injury and winging scapula and who were included in our previously published studies.^9-11

  2. Teen patients who have no postoperative follow-up.

This was a retrospective study of 16 teen patients who had winging scapula and therefore underwent LTN decompression between 2005 and 2016, as described in our previous publications.^9,10 The average patient age was 17 years (range, 14-19 years). Patients had been suffering from paralysis for an average of 1.3 years (range, 2-48 months). All patients underwent a preoperative electromyographic assessment in addition to clinical evaluation to confirm the LTN injury. We adopted a 4-point numerical scale for determining the extent of scapula winging: 1, severe; 2, moderate; 3, mild; and 4, normal as shown in Figure 1. The angle of humeral elevation before and after surgical neurolysis of the LTN was captured on the video. Stills were taken from the video of the patients performing abduction, and the angle between a line parallel to the medial line and the humerus was measured (0° being relaxed at the side and 180° being fully abducted above the head). The paired Student t-test statistics was applied to compare the pre- and postoperative mean Mallet and supination scores using the Analyze it plugin (Leeds, UK) for Microsoft Excel 2003. A value of P < .05 was considered statistically significant.

Figure 1. Extent of scapular winging range, 1-4: 1, severe; 2, moderate; 3, mild; 4, normal.

This was a retrospective study of patient charts, which exempted it from the need for institutional review board approval in the United States. Patients were treated ethically in compliance with the Helsinki declaration. Documented informed consent was obtained for all patients.

Of 16 teen patients in our present study, 9 patients (56%) had a sports-related injury and 5 patients (31%) had accidents (3 motor vehicle accidents and 2 falls). In the other 2 patients (13%), the cause of the injury was not known (Table 1). Scapula winging was severe in 10 of 16 patients (63%), moderate in 2 patients (12%), and mild in 4 patients (25%) in our present study. Mean shoulder abduction and flexion were preoperatively 128° and 138°, respectively (Table 2).

All patients showed some improvements in shoulder movements on the next day of the LTN decompression procedure. The improvement in shoulder AROM was excellent (180°) in 15 patients (94%) and good (120°) in 1 patient (6%) after at least 2 months of post-LTN decompression follow-up (Fig 2). The winged scapula was completely corrected in 11 patients (69%), and it was less prominent in other 5 patients (Fig 2). The patients in this study did not have EMG/nerve conduction velocity test after surgery. Although EMG is diagnostically helpful,^11,12 the improvement over time on serial EMG examination may¹³ or may not¹² correlate with clinical outcome.¹⁴

Figure 2. Excellent recovery of shoulder movements (abduction 180°) after LTN decompression and neurolysis. (A, B) Photographs of a female teen patient (16.5 years old) who had winging scapula due to an accident or fall. (A) Preoperative photograph showing clearly winged scapula. (B) Post-LTN decompression photograph showing excellent recovery and full AROM (shoulder abduction 180°). (C, D) Photographs of a male teen patient (19 years old) who had winging scapula due to a motor vehicle accident. (C) Preoperative photograph showing winging scapula. The patient recovered full AROM (shoulder abduction 180°) 2 months after LTN decompression (D). LTN indicates long thoracic nerve; AROM, active range of motion.

We^8-10 and other investigators^15-17 have demonstrated that surgical release of LTN and spinal accessory nerve¹⁸ as a simple and effective treatment that significantly improves winging scapula and shoulder AROM,^8-10 which relieves pain and provides complete motor recovery,¹⁵ when performed within the first 12 months of the paralysis.¹⁵ In addition, in our previously published meta-analysis report,⁸ we compared and analyzed the outcomes of long thoracic or spinal accessory nerve decompression and neurolysis with muscle transfer procedures and found that nerve surgical procedures are effective techniques in correcting winging scapula in comparison with muscle and tendon transfer operations.

Vastamäki et al¹⁹ recently reported how etiology influences long-term outcome of LTN damage. They found that LTN-related palsies caused by infection recover better and those caused by surgery in the body or anesthesia¹⁹ recover most poorly. These palsies caused by acute trauma or acute or chronic overuse of upper extremities had the same recovery period as other patients. Etiology of LTN injury had less influence on long-term outcomes. We did not have any patient in this study who had LTN injury and winging scapula due to infection. Our patients’ outcome data and recovery also substantiate the findings of Vastamäki et al.¹⁹ Our data confirm that etiology did not influence significantly in our patient outcomes after surgical LTN decompression treatment.

Mechanism of LTN injury is generally mechanical in origin. Most of our patients in this study had sports-related injuries, and these are mechanical in nature. Glenohumeral instability, scapula winging, proximal humeral physis, and shoulder pain are important to recognize and address early, as these can cause more severe complications later in these growing teen and preteen athletes and other young patients.

Both LTN decompression and neurolysis significantly improved scapular winging in all 16 teen patients in our present study, producing “excellent” shoulder movements in 15 patients (94%) and “good” result in one patient (6%).

The authors thank the patients and families who participated in this study.

R.K.N. conceived the study, performed all the surgical procedures, and revised the manuscript. C.S. participated in the design of the study, gathered data, performed the statistical analysis, and drafted the manuscript. Both authors read and approved the final manuscript.