Sciatic nerve regeneration in the rat. Validity of walking track assessment in the presence of chronic contractures.

The ability of the walking track assessment of sciatic nerve function to correlate with results of a nerve repair has been well documented following acute nerve injury and after recovery of the nerve following nerve repair. The long-term effects of partial denervation upon the lower extremity of the rat include the development of chronic contractures due to residual partial muscle paralysis and imbalance. The present study evaluated the ability of the walking track technique to portray accurately the walking pattern in animals following chronic contracture as a result of sciatic nerve repair. Animals 18 months and 24 months after sciatic nerve repair were found to have morphometric analysis distal to the repair that was not statistically significantly different from normal. However, the walking track assessment was inadequate at twenty-four months due to the development of clawing, interphalangeal joint contractures, and ankle inversion or eversion with or without dorsiflexion. The presence of these chronic deformities invalidated the walking track as an appropriate assessment technique for long-term assessment of nerve function following nerve repair.