The value of the tender muscle sign in detecting motor recovery after peripheral nerve reconstruction

Resect, rewire, and restore: Nerve transfer salvage of neurological deficits associated with soft tissue tumors in a retrospective cohort series at a tertiary reconstructive center

AIMS

We aimed to explore the effectiveness of nerve transfer as an intervention to restore neurological deficits caused by extremity tumors through direct nerve involvement, neural compression, or as a consequence of oncological surgery.

METHODS

A retrospective cohort study of consecutive cases was conducted, including all patients who underwent nerve transfers to restore functional deficits in limbs following soft tissue tumor resection. The threshold for a successful nerve transfer was a BMRC motor grade of 4/5 and sensory grade of 3-3+/4 with protective sensation.

RESULTS

In total, 29 nerve transfers (25 motor and 4 sensory) were completed in 11 patients, aged 12-70 years at referral, over a 6-year period to 2020. This included 22 upper limb and 3 lower limb motor nerve transfers. The timing of delayed nerve transfer reconstructions was 1-15 months following primary oncological resection, with immediate simultaneous reconstructions performed in 4 cases. The threshold for success was achieved in 82% of upper limb and 33% of lower limb motor nerve transfers, while all sensory transfers were successful in restoring protective sensation.

CONCLUSION

Nerve transfer surgery, a well-established technique in restoring deficits following traumatic nerve injury, is further demonstrably relevant in extremity oncological reconstruction, especially as it can be performed remotely to the tumor location or resection site and introduces a healthy nerve or fascicle to rapidly reinnervate distal muscles without sacrificing major function. This study further illustrates the importance of early recognition and referral to specialist services where multi-disciplinary surgical resection and reconstructive planning can be conducted.

LEVEL OF EVIDENCE

IV Clinical Case Series.

A Surgical Framework for the Management of Incomplete Axillary Nerve Injuries

BACKGROUND

 Axillary nerve injury is the most common nerve injury affecting shoulder function. Nerve repair, grafting, and/or end-to-end nerve transfers are used to reconstruct complete neurotmetic axillary nerve injuries. While many incomplete axillary nerve injuries self-resolve, axonotmetic injuries are unpredictable, and incomplete recovery occurs. Similarly, recovery may be further inhibited by superimposed compression neuropathy at the quadrangular space. The current framework for managing incomplete axillary injuries typically does not include surgery.

METHODS

 This study is a retrospective analysis of 23 consecutive patients with incomplete axillary nerve palsy who underwent quadrangular space decompression with additional selective medial triceps to axillary end-to-side nerve transfers in 7 patients between 2015 and 2019. Primary outcome variables included the proportion of patients with shoulder abduction M3 or greater as measured on the Medical Research Council (MRC) scale, and shoulder pain measured on a Visual Analogue Scale (VAS). Secondary outcome variables included pre- and postoperative Disabilities of the Arm, Shoulder, and Hand Questionnaire (DASH) scores.

RESULTS

 A total of 23 patients met the inclusion criteria and underwent nerve surgery a mean 10.7 months after injury. Nineteen (83%) patients achieved MRC grade 3 shoulder abduction or greater after intervention, compared with only 4 (17%) patients preoperatively (p = 0.001). There was a significant decrease in VAS shoulder pain scores of 4.2 ± 2.5 preoperatively to 1.9 ± 2.4 postoperatively (p < 0.001). The DASH scores also decreased significantly from 48.8 ± 19.0 preoperatively to 30.7 ± 20.4 postoperatively (p < 0.001). Total follow-up was 17.3 ± 4.3 months.

CONCLUSION

 A surgical framework is presented for the appropriate diagnosis and surgical management of incomplete axillary nerve injury. Quadrangular space decompression with or without selective medial triceps to axillary end-to-side nerve transfers is associated with improvement in shoulder abduction strength, pain, and DASH scores in patients with incomplete axillary nerve palsy.

Supplementary motor area deactivation impacts the recovery of hand function from severe peripheral nerve injury

Although some patients have successful peripheral nerve regeneration, a poor recovery of hand function often occurs after peripheral nerve injury. It is believed that the capability of brain plasticity is crucial for the recovery of hand function. The supplementary motor area may play a key role in brain remodeling after peripheral nerve injury. In this study, we explored the activation mode of the supplementary motor area during a motor imagery task. We investigated the plasticity of the central nervous system after brachial plexus injury, using the motor imagery task. Results from functional magnetic resonance imaging showed that after brachial plexus injury, the motor imagery task for the affected limbs of the patients triggered no obvious activation of bilateral supplementary motor areas. This result indicates that it is difficult to excite the supplementary motor areas of brachial plexus injury patients during a motor imagery task, thereby impacting brain remodeling. Deactivation of the supplementary motor area is likely to be a serious problem for brachial plexus injury patients in terms of preparing, initiating and executing certain movements, which may be partly responsible for the unsatisfactory clinical recovery of hand function.