Outcomes of ulnar nerve grafting

The ulnar nerve is a mixed motor and sensory nerve, which making nerve repair more difficult and functional recovery less predictable than pure sensory nerves. Recovery of muscle activity and restoration of sensibility are essential for a functional extremity. A nerve graft, if performed in a tensionless manner, has been shown to generally have better results than an end-to-end approximation performed under tension.

In study period from 1993 through 2008, evaluation was performed in 48 patients with adequate follow-up. The mean follow-up period was 3.4 years (range, 24 months to 8.3 years). The average patient age was 32.4 years (range, from 6 to 71 years). There were 37 male patients and 11 female patients.

We analyzed the effect of the age of the patient, level of injury, graft lenght and denervation time on motor and sensory recovery. Values of p < 0.05 were considered significant. Results of motor (chi-square = 8.04, p = 0.154) and sensory recovery (chi-square = 7.53, p = 0.184) were not significantly better in patients younger than 25 years compared to the group of patients older than 25 years. The level of the ulnar nerve injury had an impact on the outcome, with better results both sensory (chi-square = 161., p = 0.000) and motor recovery (chi-square = 238., p = 0.000) in patients with distal lesions. The results were significantly better in the group with graft lenght less than 5 cm compared to those longer than 5 cm for both sensory (chi-square = 72.6, p = 0.000) and motor recovery (chi-square = 196., p = 0.000). The functional results were significantly better for both sensory (chi-square 13.4, p = 0.020) and motor recovery (chi-square = 133., p = 0.000) in the group of patients with denervation time shorther than 6 months.

The graft length, level of injury and denervation time significantly influenced the functional outcome in both motor and sensory recovery. Better results were in the patients in which the autograft length was up to 5 cm, in patients who were operated within six months from the injury and in patients with distal lesions.