The effect of electrical stimulation on lumbar spinal fusion in older patients: a randomized, controlled, multi-center trial: part 1: functional outcome.

Study Design: Randomized, controlled, multi-center trial.

Objective: To investigate the effect of direct current (DC) electrical stimulation on functional and clinical outcome after lumbar spinal fusion in patients older than 60 years.

Summary Of Background Data: Older patients have increased complication rates after spinal fusion surgery. Treatments which have the possibility of enhancing functional outcome and fusion rates without lengthening the procedure could prove beneficial. DC-stimulation of spinal fusion has proven effective in increasing fusion rates in younger and "high risk" patients, but functional outcome measures have not been reported.

Methods: A randomized, clinical trial comprising 5 orthopedic centers. The study included a total of 107 patients randomized to uninstrumented posterolateral lumbar spinal fusion with or without DC-stimulation. Functional outcome was assessed using Dallas Pain Questionnaire, SF-36, Low Back Pain Rating Scale pain index, and walking distance.

Results: Follow-up after 1 year was 95/107 (89%). DC-stimulated patients had significant better outcome in 3 of 4 categories in the Dallas Pain Questionnaire, better SF-36 scores (not significantly), but no difference in pain scores were observed. Median walking distance at latest follow-up was better in the stimulated group (not significant). Walking distance was significantly associated with functional outcome. There was no difference in any of the functional outcome scores between patients who experienced a perioperative complication and those without complications.

Conclusion: The achievement of a good functional outcome was heavily dependent on the obtained walking distance. DC-stimulated patients tended to have better functional outcome as compared to controls. No negative effects of perioperative complications could be observed on the short-term functional outcome.