Functional outcomes of instrumented posterior lumbar interbody fusion in active-duty US servicemen: a comparison with nonoperative management.

Abstract Background context: The existing literature lacks a functional outcome study addressing instrumented posterior lumbar fusion surgery in physically active patients. Furthermore, results of operative versus nonoperative treatment in these patients are not clear. Purpose: To evaluate patient-assessed function, pain, and satisfaction and military job performance between servicemen treated operatively and nonoperatively. Study design/setting: This is a nonrandomized analysis of consecutive active-duty military servicemen treated either operatively or nonoperatively for chronic back pain and single-level lumbar disc degeneration with emphasis on functional outcomes. Patient sample: Active-duty US servicemen with chronic low back pain. Outcome measures/methods: Twenty-nine consecutive active-duty US servicemen were treated for chronic back pain and single-level lumbar disc degeneration by the same surgeon at a military spine facility. Fifteen were treated with instrumented posterior lumbar interbody fusion (PLIF), and 14 refused surgery and chose to be treated nonoperatively with spinal extensor muscle-strengthening exercise, medications, and restricted duty. The average follow-up time was 14 months (range, 6 to 24 months). All servicemen completed a functional outcome questionnaire American Academy of Orthopedic Surgeons/Scoliosis Research Society (AAOS/SRS) with emphasis on pre- and posttreatment function, pain, and satisfaction. The two groups were also compared using military job performance parameters. Results: Four of 14 (28%) of the servicemen treated nonoperatively ultimately received a disability discharge from the military for back pain, another 5 of 14 (36%) remained on permanent duty-restriction profiles, and only 5 of 14 (36%) returned to full, unrestricted military duty. In the PLIF group, 12 of 15 soldiers (80%) were able to return to full duty, only 3 of 15 (20%) remained on permanent restrictive duty-limitation profiles, and 0 of 15 (0%) received a disability discharge from the military for back pain. Twelve of 15 (80%) of the PLIF group and 8 of 14 (57%) of the group treated nonoperatively were physically able to complete the posttreatment physical fitness test. No difference was observed between premorbid and posttreatment physical training (PT) test scores in either group. However, scores for patient-assessed posttreatment pain, function, and satisfaction were significantly higher in the PLIF group. Soldiers who were able to return to full military duty did so at an average of 2 months for the group treated nonoperatively (n = 5) and 4 months for the PLIF group (n = 12). Complications in the PLIF group included dural tear (n = 2), unilateral transient lower extremity paresthesia (n = 1), and wound seroma requiring reoperation (n = 1). Conclusions: In this nonrandomized study of 29 active-duty US servicemen with chronic low back pain and single-level lumbar disc degeneration, instrumented PLIF surgery was associated with a high rate of return to full military duty. Servicemen treated with this technique were less likely to receive a back pain disability discharge or a permanent physical limitation profile when compared with servicemen who chose to be treated nonoperatively. Outcomes with respect to postreatment pain, function, and satisfaction were higher in patients treated with instrumented PLIF and were excellent in servicemen who were able to return to full duty regardless of treatment.