Saphenous nerve neuralgia: A potentially devastating complication of perioperative adductor canal block used for total knee arthroplasty analgesia

Objectives: Adductor canal blocks are commonly employed for post-operative pain control in total knee arthroplasty (TKA), offering advantages such as reduced opioid use, faster quadriceps recovery, and earlier discharge. However, the incidence of sartorial branch saphenous neuralgia – a potentially debilitating complication – remains poorly characterized. This study aims to evaluate its occurrence following perioperative adductor canal block in a community-based setting. Methods: A total of 206 TKA patients were observed, and anesthesia types were documented alongside the incidence of persistent sartorial branch saphenous neuralgia and paresthesia at a two-month follow-up. Sixty-nine patients received adductor canal blocks, 15 received femoral nerve blocks, and 14 had popliteal blocks in combination with femoral or adductor blocks. The remaining 123 underwent general or spinal anesthesia without peripheral nerve blocks. All nerve blocks were ultrasound-guided. Results: Of the 69 patients who received adductor canal blocks, 5 (7.2%) developed persistent saphenous neuralgia. Three patients (4.3%) experienced severe symptoms requiring referral to pain management and further intervention. Two (2.9%) had milder cases managed conservatively. No neuralgia was reported in patients who received femoral or popliteal blocks, or those who had spinal or general anesthesia alone. Conclusion: Saphenous neuralgia occurred in 7.2% of patients following adductor canal block, with some cases severe enough to require further treatment. Given the potential to impede recovery, this risk should be discussed during informed consent, and clinicians should monitor for symptoms. Although adductor canal blocks are effective, their use should be considered on a case-by-case basis rather than assumed universally appropriate.