Outcomes of Surgical Treatment for Sural Neuritis: A Retrospective Case Series.

BACKGROUND: Somatic nerve pain is one of the most common complications following surgery of the foot and ankle but may also arise following traumatic injury or chronic nerve compression. The sural nerve is a commonly affected nerve in the foot and ankle; it is at risk given the proximity to frequently used surgical approaches, exposure to crush injuries, and traction from severe ankle inversion injuries. The purpose of this study is to investigate the outcomes of sural nerve neurectomy with proximal implantation for sural neuromas (SN) and chronic sural neuritis (CSN).

METHODS: Patients that underwent neurectomy with proximal implantation (20 muscle, 1 adipose tissue) by 2 foot and ankle specialists for isolated SN- and CSN-related pain at a single tertiary institution were included. Demographic data, baseline outcomes including 36-Item Short Form Health Survey (SF-36), Foot and Ankle Ability Measure (FAAM), and visual analog scale (VAS) were recorded. Final follow-up questionnaires using Patient Reported Outcomes Measurement Information System (PROMIS) lower extremity function, pain interference (PI), and neuropathic pain quality, FAAM, and VAS were administered using REDCap. Perioperative factors including neuropathic medications, diagnostic injections, the use of collagen wraps, and perioperative ketamine were collected from the medical record. Descriptive statistics were performed and potential changes in patient-reported outcome measure scores were evaluated using Wilcoxon signed-rank tests.

RESULTS: The 21 patients meeting inclusion criteria for this study had a median age of 47 years (interquartile range [IQR], 43-49) and had median follow-up duration of 33.7 months (IQR, 4.5-47.6). Median FAAM activities of daily living score improved from 40.6 (38.7-50.7) preoperatively to 66.1 (53.6-83.3) postoperatively, P  = .032. FAAM sports scores improved from 14.1 (7.8-21.9) to 41.1 (25.0-60.9) postoperatively, P  = .002. VAS scores improved from a median of 9.0 (8.0-9.0) to 3.0 (3.0-6.0), P  < .001. At final follow-up, patients reported PROMIS lower extremity function score median of 43.8 (35.6-54.9), PROMIS neuropathic pain quality score of 54.1 (43.6-61.6), and PROMIS PI of 57.7 (41.1-63.8). Patients with both anxiety and depression reported less improvement in pain and physical. Other perioperative factors lacked sufficient numbers for statistical analysis.

CONCLUSION: Sural nerve neurectomy and proximal implantation (20 muscle, 1 adipose) provided significant improvement in pain and function for patients with sural neuromas and chronic sural neuritis at median follow-up of 33.7 months. Anxiety and depression were associated with significantly poorer outcomes following surgery. Patients with CRPS as well as recent nicotine use tended to report less improvement in pain and worse function after surgery, although this sample size was too limited for statistical analysis of these variables. Further research is needed to identify the ideal surgical candidates and perioperative factors to optimize patient outcomes.

LEVEL OF EVIDENCE: Level IV, retrospective case series.