Single cylindrical threaded cage used in recurrent lumbar disc herniation

OBJECTIVES: Where fusion is being considered after repeated discectomy for recurrent lumbar disc herniation (RLDH), interbody fusion is reasonable. But interbody fusion by dual cages inserted posteriorly is difficult because of the scarring from the previous surgery. Under this consideration, a prospective clinical study of RLDH operated on by posterolateral placement of a single cylindrical threaded cage through the virgin side after decompression was conducted. The study is not intended to indicate when to fuse the recurrent herniation but to evaluate the efficacy of this fusion method for these patients whenever fusion is necessary. METHODS: From November 1998 to April 2000, 14 RLDH patients were enrolled after failure of conservative treatment. Eleven patients had a lesion at L4-L5 and three at L5-S1. Two patients experienced disc reherniation on the side opposite the original injury, whereas the subsequent reherniation was ipsilateral for the other 12. CONCLUSIONS: In this series, there was no evidence of dural tears or neurologic deficits, but three temporary superficial wound infections, one urinary tract infection, and one asymptomatic disc wedging were experienced. As for the result of interbody fusion by cage, 12 patients (85.8%) achieved successful fusions; the other two had radiolucency along the cage-endplate interfaces and were therefore defined as failure of interbody fusion. Satisfactory clinical results were achieved for 13 patients (92.9%; excellent [n = 6], good [n = 7]) using this procedure.