Anterior BAK instrumentation and fusion: complete versus partial discectomy.

Beginning in January 1994, a prospective, clinical study was done comparing the effectiveness of complete anterior (Group 1) versus partial reamed channel discectomies (Group 2) in 100 consecutive patients who had anterior BAK instrumentation and fusion using autogenous iliac crest bone graft. At 2 or more years of followup, all patients in Group 1 who had complete operative disc removal achieved solid arthrodesis. There were no revision surgeries. However, in Group 2, there were seven patients who had a pseudarthrosis and an additional patient with early postoperative cage displacement, which resulted in eight patients in Group 2 requiring revision surgery. The differences in operative preparation of the disc space for BAK instrumentation surgery resulting in complications proved to be significant. The use of interbody titanium cages dramatically increases the biomechanical efficacy of anterior fusions. Original proponents of cages advocated removing a cylindrical channel of disc material using a drill. A prospective review of 100 patients who had complete versus partial discectomy revealed 14% of patients in Group 2 eventually had a pseudarthrosis develop.