Comparison of ulnar nerve repair according to injury level and type

The aim of the study was to evaluate the results of epiperineural suture repaired primary (clean transaction injury, massive soft-tissue associated injury) and secondary (delayed partial injury) ulnar nerve injuries according to lesion level and type.

Forty-two patients diagnosed with ulnar nerve injury between January 2008 and January 2012 were involved in the study. Ulnar nerve lesions were classified according to the level of injury into three types: type 1--lesion located above the flexor carpi ulnaris branch; type 2--lesion located between the flexor carpi ulnaris and the flexor digitorum profundus III and IV; type 3--lesion located below the flexor digitorum profundus III and IV and no more than 10 cm distal from the elbow crease. Additionally, ulnar nerve lesions were classified according to type into three groups: group 1 (n 17)--clean transaction injury; group 2 (n 14)--massive soft-tissue associated injury; group 3 (n 11)--delayed partial clean transaction injury. In follow-up evaluations, sensory and motor recovery was analysed with the most common Highet scale modified by Dellon et al. Functional results were evaluated according to the Disability of Arm, Shoulder, and Hand (DASH) score at final follow-up.

There were no statistically significant differences between groups according to men/women ratio, mean age, mean follow-up period and ulnar-nerve injury level. The DASH score was significantly better in the clean transaction injury group than the other groups and significantly better for type 3 than types 1 and 2 injuries in all groups. Sensory recovery of type 1 and 3 injuries in the massive soft-tissue associated injury group was significantly worse than the other groups. The worst motor recovery was evaluated in type 1 injury and the best in type 3 injury according to injury level. According to group, motor recovery of the massive soft-tissue associated group was significantly worse than the other groups in all injury types. There were no statistically significant differences between clean transaction injury and delayed partial clean transaction injury groups in all injury types.

Prognostic factors that influenced motor-sensory recovery and functional results were found in interval between trauma and reconstruction, injury level (worse results from proximal to distal) and mechanism of injury (worse results from massive soft-tissue injury to clear, sharp-tissue injury).