Introduction

• The Problem: Sensory nerve harvest (sural nerve) is the gold standard for autologous reconstruction but is associated with significant donor-site morbidity, including paresthesias (87.2-92.9%), chronic neuropathic pain (19.7-25.6%), and functional impairment (5-10%). 

• Targeted Muscle Reinneration (TMR): Performing TMR at the proximal sural nerve stump may mitigate donor-site pain. 

• The Innovation: Lower extremity motor nerves (Femoral Motor Nerve to Vastus Lateralis - MNVL) offer redundant innervation and may avoid sensory-related morbidity.

• Hypothesis: MNVL will result in the fewest donor site sensory symptoms, followed by the sural nerve with TMR cohort.

Methods

• Study Design: Retrospective chart review (2015–2024).

• Cohorts (N = 50):

• Cohort 1: Sural nerve harvest without TMR (n = 18).

• Cohort 2: Sural nerve harvest with TMR (n = 18).

• Cohort 3: MNVL harvest (n = 14).

• Outcome Measures: Follow-up notes were screened for subjective symptoms, final sensory deficits, and donor-site pain.

Surgical Technique: MNVL Harvest

• Axis: Defined by the Anterior Superior Iliac Spine (ASIS) to the lateral patella.

• Dissection:

• Interval developed between the rectus femoris and vastus lateralis.

• The nerve is reliably found in this raphe, branching off the femoral nerve at the level of the greater trochanter.

• The distal motor branch is the clinical target, verified with intraoperative stimulation.

Results

• Inciting Events: Majority of cases were due to traumatic causes (67-71%), followed by surgical/iatrogenic, then oncologic reasons. 

• Sensory Outcomes: Loss of sensation at final follow-up was significantly less in the MNVL group compared to both sural cohorts (p = 0.01).

• Pain Outcomes: Cohort 2 (Sural + TMR) and Cohort 3 (MNVL) were individually superior to Cohort 1 (Sural - No TMR) (p = 0.02 and p = 0.003).

• Equivalency: No significant difference in pain was found between Sural + TMR and MNVL (p = 0.437).

• Functional Safety: No MNVL patients experienced disturbances to ADLs.

Discussion & Clinical Implications

• A New Alternative: MNVL is a viable autograft option that provides adequate length for many reconstructions while minimizing permanent sensory loss.

• Optimizing the Gold Standard: For cases requiring the sural nerve (e.g., long cable grafts), performing TMR at the harvest site significantly limits chronic pain.

• Patient Selection: The senior authors prefer MNVL for shorter, distal nerve injuries or for patients already experiencing preoperative nerve pain to avoid creating a secondary pain site.