Session II - Spine

Longterm Follow-Up of Operative Treatment of Low Lumbar Burst Fractures

Alan M. Levine, MD, Walter Virkus, MD

University of Maryland Medical Center, Baltimore, Maryland, USA

Treatment of fractures involving the low lumbar spine has been controversial. Due to the extreme mobility of the area and the normal lordotic sagittal alignment, operative fixation has been difficult. Early studies of operative treatment showed a high complication rate and more recent studies demonstrate adequate outcome with nonoperative treatment. However, all studies to date had relatively short follow-up (less than 5 years) and a high incidence of residual back pain in a relatively young population.

Twenty-nine patients admitted to the Spinal Injury Unit with a low lumbar burst fracture between 10/86 and 11/91 underwent surgical stabilization. There were 24 males and 5 females with a mean age of 33 years. There were 7 L5 fractures, 13 L4 fractures and 9 L3 fractures. Indications for surgery were neurologic deficit (15 pts.) and/or severe instability/deformity (21 pts.). All patients were operated on by a single surgeon and underwent a three level pedicle screw instrumentation with screw placement in the body above the fracture, at the fractured level and at the level below, with distraction and lordosis applied to reduce the deformity. Ten patients also underwent simultaneous laminectomy for repair of a traumatic dural laceration. All patients underwent postoperative mobilization in a TLSO for six months. Follow-up consisted of AP and lateral roentgenograms, physical examination and/or telephone interview concerning functional status.

Of the original 29 patients, 4 patients have died (1.75, 2, 4, 7 years) and 4 are lost to follow-up. Of the remaining 21 patients, the mean follow-up is 6.9 years with a range of 3.2 to 10.2 years. All but 3 patients have had complete motor recovery, and 4 still have minor numbness or paresthesias. Six broken pedicle screws have been identified (4 patients), but only 1 patient has been revised for nonunion. One patient underwent foraminotomy for persistent radiculopathy and 1 underwent hardware removal for prominence. One patient was disabled before the fracture and 2 are currently on disability. Fourteen patients are currently doing the same or similar work as pre-injury, with only 2 doing less strenuous work. Nine patients are doing heavy labor such as construction. Only 4 take pain medications on a regular basis. Four patients feel their work status has been affected by the surgery and 7 feel their recreational status has been affected. All but 1 patient are satisfied with the results of the surgery.

Low lumbar fractures occur in a relatively young population affecting the most mobile and highly stressed portion of their spine. Sagittal alignment is often severely disrupted but short term studies of non-operative treatment suggest adequate outcome, but with a high incidence of back pain. These studies demonstrate that by achieving accurate restoration of alignment and solid arthrodesis in longer term follow-up, (5-10 years) back pain is relatively infrequent and restoration of pre-fracture life style is possible.