Surgical Management of Intracanal Rib Head Dislocation in Neurofibromatosis Type 1 Dystrophic Kyphoscoliosis: Report of Two Cases and Literature Review

Abstract

There is still no consensus on the management of severe intracanal RH dislocation in neurofibromatosis type 1 dystrophic kyphoscoliosis. This study notes the early cord function impairment signs, reports a serious complication in a susceptible cord, identifies possible mechanisms of injury, and discusses the management of intracanal RH dislocation presented in the literature. First report is as follows: a 12-year-old female with cord compromise and preoperative neurology that underwent thoracotomy and anterior release. The RH was left in situ following a rib excision. During the posterior stage of the procedure she presented with complete loss of all IOM traces prior to any correction manoeuvres. The neurology recovered 72 h postop and the final correction and instrumented fusion were uneventfully completed 15 days postop. Second report is as follows: a 10-year-old male, whose only neurology was a provoked shock-like sensation to the lower limbs following direct pressure on the rib cage. He underwent an uneventful posterior RH excision and instrumented correction and posterior spinal fusion. In conclusion, any possible cord dysfunction sign should be sought during examination. Decompression of the spinal cord by resecting the impinging bony part, even in the absence of neurological symptoms, is advised before any attempt to release or correct the deformity.