Autoamputation of the first sacral nerve roots in spondyloptosis.

To our knowledge, this is the first reported case of bilateral autoamputation of the first sacral nerve roots in a patient who has spondyloptosis. The authors think that autoamputation occurred in adolescence during a period of rapid forward displacement of the fifth lumbar vertebra on the sacrum. It is postulated that the lack of motor weakness is due to the long-standing nature of the denervation and that other adjacent nerve roots supplying the triceps surae have, over time, increased the power of those muscle fibers not supplied by the first sacral roots. This finding would encourage development of methods for early reduction and fusion in children showing marked restriction of straight leg raising (ie, tight hamstrings) to prevent rapid listhesis and fixation of the fifth lumbar vertebra to the sacrum.