Translaminar screw fixation of the lumbar spine: long-term outcome.

Study Design: Retrospective clinical cohort study.

Objectives: To evaluate the long-term results after translaminar screw fixation of the lumbar spine in a large group of patients and to identify predictors of a good outcome.

Summary Of Background Data: Translaminar screw fixation represents an alternative operative technique to transpedicular fixation systems for short-segment lumbar fusion. The strategy behind this technique is to block the facet joints with perforating screws. Although the method has been in use for more than 20 years, few studies reporting the long-term outcome in large groups of patients are to be found in the literature.

Methods: The Core Outcome Measures Index, a multidimensional outcome questionnaire, was sent to 643 consecutive patients who had undergone lumbar fusion with translaminar screws between 1987 and 2004, for various degenerative conditions of the lumbar spine. Patients also rated the global outcome and their satisfaction with treatment. Disc height was measured from preoperative radiographs using the distortion compensated roentgen analysis method. 476 patients (74%) completed and returned the questionnaire. Multiple logistic regression analysis was used to identify factors associated with a good outcome.

Results: After an average follow-up period of 10 years (range: 2-20 years) 352 of 476 patients (74%) reported that the operation had either "helped a lot" or "helped" (good outcome); 124 of 476 patients (26%) declared that it "helped only little," "didn't help," or "made things worse" (poor outcome). Controlling for potential confounders, a preoperative disc height <80% of that reported for a normal population was the most significant unique predictor of a good outcome (OR = 14.86, 95% CI: 6.77-32.61, P < 0.0001).

Conclusion: Translaminar screw fixation is a straightforward and effective technique for short-segment fusion in the lumbar spine. For patients with a strict indication for spondylodesis, intact posterior elements (lamina and facets) and a low preoperative disc height, translaminar screw fixation represents a successful fixation technique in the lumbar spine with good long-term results.