A 10-year follow-up evaluation of lumbar spine fusion with pedicle screw fixation

Study Design. A retrospective cohort study was conducted. Objective. To evaluate the long-term results of lumbar spine fusion supplemented with pedicle screw fixation. Summary of Background Data. Pedicle screw fixation of the lumber spine is widely used, yet there is little long-term follow-up information on the technique. Methods. All adult patients treated at the University of Iowa. Department of Orthopedic Surgery with lumbar pedicle screw fixation between March 10, 1986 and July 1, 1991 were reviewed All the patients initially had answered a battery of questions regarding pain and disability and had radiographs-performed. At follow-up evaluation, the same and other questions regarding their status were asked and SF-36 was used. Radiographs were reviewed for evidence of hardware complications, fusion status, deformity and extent of degeneration around the fusion. Results. In this study, 234 patients underwent 236 pedicle screw fixation procedures. Indications for surgery were degeneration (n = 127), trauma/instability (n = 33), pseudarthrosis (n = 17), deformity (n = 16), tumor (n = 4), inflammatory process (n = 4), infection (n = 1), and unknown (n = 32). Variable screw placement (Acromed, Cleveland Ohio) fixation was used in all cases. Nonintegral locking nuts were used in 119 cases. Of the 234 patients 31 had died, 5 had been eliminated because the chart review indicated that their reason for surgery was tumor or infection and 92 were lost to follow-up evaluation for various reasons. Of the remaining 107 patients 13 had incomplete data, leaving 94 patients with complete information. The SF-36 showed reports of bodily pain and physical functioning below age- and gender-adjusted means but disability and function scores demonstrated significant improvement at the 10-year follow-up assessment. Patient-reported satisfaction was high, approximately 80%. Radiographically, at the 10-year follow-up assessment, 242 of 244 instrumental segments showed no motion, with approximately one third of these also showing evidence of definite fusion. Conclusions. At a minimum follow-up evaluation of 10 years, lumbar fusion with pedicle-screw fixation showed relatively good functional capacity, especially relative to the baseline, a low rate of radiographic failure, satisfaction of patients with their progress, a low rate of repeat surgery, and minimal surgical and hardware related complications.