gms | German Medical Science

Objective: The peroneal nerve is the most frequently affected nerve amongst traumatic nerve lesions of the lower limb. Compared to reconstructive results of other commonly injured nerves (e.g. radial) functional outcome is often disappointing. We present our experience with this type of injury.

Methods: In a retrospective study 48 patients with traumatic lesions (17 iatrogenic) of the peroneal nerve were evaluated. They had been surgically treated at our department between 1993 and 2004. Twenty-two nerves presented with lesions in continuity displaying regenerative potential by nerve action potential recording. In these cases surgery was restricted to either external- (12x) or interfascicular neurolysis (10x). Twenty-two cases had no regenerative potential or showed a discontinuity and thus were reconstructed with autologous sural nerve grafts. Graft length ranged from 2.5 to 14 cm. In four cases a reconstructive procedure was intraoperatively abandoned due to extent of lesion.

Results: Thirty six of 44 patients could be evaluated (follow-up times at least 18 months). Among those with external neurolysis 73% (8/11) showed a good functional outcome obviating the need for a kick-up foot brace (M≥4). In the interfascicular neurolysis group 71% (5/7) had such a result. In the grafted group, however only 28% (5/18) obtained a functionally useful result. Graft length seemed to affect outcome: average graft length of the five patients with good outcome was 4.3cm/ median 5cm (compared to 7.2cm/ median 6cm, of the other patients). The time between trauma and operation showed no definite effect: average 5.6 months/ median 5 months (good outcome) compared to 4.4 months/ median 5 months (others). One patient, who underwent surgery even 9 months after trauma showed a good result. On three patients with unimproved foot drop after nerve surgery, muscle-tendon transfers have recently been performed at our department resulting in a strong, useful foot lift.

Conclusions: Peroneal nerve lesions lacking regenerative signs 3 months postinjury should be explored. In 50% a useful functional result can be anticipated with an appropriate nerve procedure. Patients where nerve surgery fails to reconstitute a useful foot lift need to be evaluated in respect to a tendon transfer procedure.