The 'vulnerable nerve'; surgically acquired neuropathy in distal humeral surgery patients and the role of a tourniquet

Background: The complication of neuropathy is high in patients undergoing distal humerus surgery. Tourniquets (TQs) are typically used but can lead to nerve injury.

Methods: We present a comparative study of a pre-intervention group (n = 38) and a post-intervention group (n = 38) undergoing distal humerus surgery between November 2020 and July 2023. The intervention included TQ discontinuation and the introduction of intravenous tranexamic acid at induction. Our analysis encompasses patient, anaesthetic, and surgical variables, as well as the rates and severity of neuropathy.

Results: Post-intervention, the rate of surgically acquired or deterioration in nerve injury improved from 15.8% (n = 6) to 2.6% (n = 1). Pre-intervention, the mean TQ duration was significantly longer for patients with post-operative neuropathy versus those without (120 min, SD = 29 vs. 88 min, SD = 38, p = 0.032). Surgery duration was not significantly longer without a TQ but was associated with a greater reduction in haemoglobin (12.7 g/L, SD = 10.9 vs. 25.2 g/L, SD = 15.5, p = 0.03).

Discussion: Trauma patients have a high risk of acquiring a nerve injury following elbow surgery or deterioration of a pre-surgical nerve injury, which emphasises the concept of vulnerable nerves. The cessation of using a TQ was associated with a lower nerve injury rate, with no cases of major nerve injury and no significant increase in surgical time.