Posterior lumbar interbody fusion for revision disc surgery: review of 50 cases in which carbon fiber cages were implanted

Object. The authors undertook a study to assess the value of posterior lumb ar interbody fusion (PLIF) in which carbon fiber cages (CFCs) were placed i n patients undergoing revision disc surgery for symptoms suggesting neural compression with low-back pain. Methods. The authors followed their first 50 patients for a maximum of 5 ye ars and a minimum of 6 months after implantation of the CFCs. Patients in w hom magnetic resonance (MR) imaging demonstrated "simple" recurrent herniat ion did not undergo PLIF. Surgery was performed in patients with symptoms o f neural root compression, tension signs, and back pain with focal disc deg eneration and nerve root distortion depicted on MR imaging compatible with clinical signs and symptoms. In 40 patients (80%) pedicle screws were not u sed. Clinical outcome was assessed using the Prolo Functional Economic Outc ome Rating scale. Fusion outcome was assessed using an established classifi cation. Symptoms in 46 patients (92%) improved after surgery, and given their outco mes, 45 (90%) would have undergone the same surgery again. Two thirds of pa tients experienced good or excellent outcomes (Prolo score greater than or equal to 8) at early and late follow up. There was no difference in clinica l outcome between those in whom pedicle screws were and were not implanted (p = 0.83, Mann-Whitney U-test). The fusion rate at 2 years postsurgery was 95%. There were minimal complications, and no patients fared worse after s urgery. No patient has undergone additional surgical treratment of the fuse d intervertebral space. Conclusions. In this difficult group of patients the aim remains to improve symptoms but not cure the disease. A high fusion rate is possible when usi ng the CFCs. Clinical success depends on selecting patients in whom radiolo gical and clinical criteria accord. Pedicle screws are not necessary if fac et joints are preserved, and high fusion rates and clinical success are pos sible without them.