ABSTRACT
STUDY DESIGN: A retrospective review of the patients who have a fixation failure of instrumentalion for the spinal fusion in lumbar region. OBJECTIVES: To assess the incidence and different types of the mechanical failure of fixation and to evaluate their managements and their influences on the progression of a spinal fusion and to the clinical outcomes. SUMMARY OF LITERATURE REVIEW: Most of the spine surgeons have been experiencing the mechanical failures after instrumentations for a spinal fusion, eden though the incidence is decreasing with a modification of the implants. Reports on this problem are sporadic in conjunction with the other topics, rarely focusing on their management and their influences on the final outcomes. MATERIALS AND METHODS: 338 consecutive patients who had a lateral fusion in the lumbar region with an instrumentation of pedicle screws and rods, mostly with decompression, were reviewed to analyse the fixation failures of instrumentation after surgery. RESULTS: There were 26 patients (7.7%) who had the fixation failures of instrumentation, in terms of loosening around the pedicle screws in 18 patients (5.3%), the breakage of the pedicle screws in fide patients (1.5%), and the migration of a rod in three patients (0.9%). They were managed by prolonged use of brace and ergonomic back cares. Even with the fixation failures, 19 patients (73.1%) disclosed solid union uneventfully, but one patient had re-operation to obtain solid fusion. The final outcomes were satisfactory in 22 patients (84.6%), including four of six patients who had pseudoarthrosis. CONCLUSIONS: The fixation failure of instrumentation after a spinal fusion in lumbar region was not rare, but the progression of a spinal fusion usually quite well achieved and the final outcomes were not so bad, even with the implant failures and pseudoarthrosi s. Except for the persistently symptomatic pseudoarthrosis, only a prolonged use of brace and the ergonomic back cares are recommended for symptomatic patients.