Functional outcome of low lumbar burst fractures. A multicenter review of operative and nonoperative treatment of L3-L5.

Study Design: A retrospective review of 42 patients treated at three major medical centers for burst fractures of L3, L4, and L5. This is the largest low lumbar (L3-L5) burst fracture study in the literature to date. The study was designed to assess both radiographic and clinical outcomes in a cohort of patients treated during a 16-year period.

Objectives: The objective of this study was to determine whether conservatively treated patients with low lumbar burst fractures had satisfactory outcomes compared with those in a surgically treated cohort of patients. The study included patients with and without neurologic deficits.

Summary Of Background Data: Burst fractures of the low lumbar spine (L3-L5) represent a small percentage of all spine fractures. The iliolumbar ligaments and location below the pelvic brim are two stabilizing factors that are unique to these fractures when compared with burst fractures at the thoracolumbar junction.

Methods: Forty-two (n = 42) patients with low lumbar burst fractures were identified from 1980 through 1996. Medical records, radiographs, and follow-up Dallas Pain Questionnaires were obtained. Loss of anterior vertebral height, kyphotic angulation, and amount of retropulsion were recorded at several phases of treatment. Mean follow-up time was 45.2 months (range, 5-132 months). Twenty patients were treated without surgery (18 were neurologically intact, and 2 had isolated nerve root injury), and 22 underwent surgery (14 had neurologic injury, 8 were intact).

Results: No patient showed neurologic deterioration, regardless of treatment. Fracture of the third lumbar segment showed the greatest tendency toward kyphotic collapse and loss of height in the nonoperative group, although this was not reflected in the final functional outcome of both groups. The ability to return to work and achieve a good-to-excellent long-term result was not significantly different among fracture levels or between surgical and nonsurgical treatments.

Conclusions: The results of nonoperative treatment of low lumbar burst fractures were comparable with those of operative treatment. The rate of repeat surgery (41%) and absence of a clearly definable long-term functional or radiographic benefit in patients without neurologic compromise may make surgery less appealing.