Preserved Finger Flexion in Brachial Plexus Total Lesion: A Study of 16 Cases Among 989 Surgical Patients

Purpose: Brachial plexus traction injuries have conventionally been categorized as involving the C5-C6, C5-C7, C5-T1, and C8-T1 roots. In this article, we report a distinct clinical presentation of brachial plexus injury characterized by intact finger flexion with signs of complete brachial plexus injury.

Methods: From 2010 to 2022, 989 patients who sustained brachial plexus injuries were examined and underwent surgery. Prior to surgery, brachial plexus computed tomography myelography was obtained. A total of 16 patients (1.6%) with preserved finger flexion and panplexus injury were identified. Upper root exploration and spinal accessory to suprascapular nerve transfer were performed as indicated. Transfer of median nerve fascicles to the biceps motor branch was used to reconstruct elbow flexion in 11 cases, whereas fascicles from the ulnar nerve were transferred in two. Two patients underwent C5 root grafting to the musculocutaneous nerve. In one case, intercostal to musculocutaneous nerve transfer was performed. Twelve patients had adequate follow-up (average, 18.5 months).

Results: Horner sign and imaging studies demonstrating C8 and T1 root avulsion were noted in all cases. Finger flexion was partially preserved in all patients with variable involvement of the intrinsic muscles of the hand. Little finger flexor digitorum profundus and flexor carpi ulnaris were always paralyzed. After surgery, an average shoulder abduction of 60° was achieved, whereas elbow flexion recovered in 11 of 12 patients (91.7%), M4 in seven cases, and M3 in four cases. Four of 13 patients (28.6%) who underwent nerve transfer using the median nerve as a donor exhibited a reduction in finger flexion strength or a loss of motion.

Conclusions: This study demonstrates a distinct clinical presentation of brachial plexus trauma, characterized by preserved finger flexion despite complete plexus injury.

Type of study/level of evidence: Therapeutic IV.