Introduction: The management of thoraco-lumbar burst fractures remains controversial. Different authors have advocated immobilisation, external bracing or internal fixation by either anterior or posterior approaches. Advocates of posterior fixation have in general performed stabilisation one level above and one level below the site of the fracture, resulting in fixation of two motion segments. It is known that multi-segmental spinal fusion produces undesirable biomechanics. To stabilise the site of the fracture and avoid unnecessary fixation of an uninjured segment the senior author (T.S.) for selected patients has been using a novel technique of monosegmental fixation with placement of pedicle screws directly into the fractured vertebral body.

Methods: All patients with thoraco-lumbar burst fractures admitted to St Vincents and Concord Hospitals between January 2001 and October 2003 were considered for monosegmental fixation. Patients with severe osteoporosis or complete loss of vertebral body height (“vertebra plana”) were excluded. All patients underwent surgical decompression and fixation within 10 days of injury. Fixation was obtained with 4 titanium pedicle screws and a single transverse connector (Xia System Stryker Spine). Reduction of kyphotic deformity was carried out in selected patients. Average blood loss for the procedure was 250 ml with no patients requiring transfusion. All patients had a minimum of 6 months radiological and clinical follow-up.

Results: Since January 2001, 18 patients with thoracolumbar burst fractures (T10-L2) were treated with single-level pedicle screw fixation. All patients were mobilised within 10 days of surgery. One patient experienced a minor superficial wound infection. There were no other postoperative complications. All patients had a stable fusion construct at 6 weeks following surgery. No patient experienced neurological deficit or have developed a delayed kyphotic deformity. There were no instances of instrument failure. 17 out of 18 patients report no significant back pain with any limitation of function by three months following surgery. One patient reports mild mechanical lower back pain 12 months following the injury.

Discussion: Single level fixation for selected cases of thoracolumbar burst fracture is a safe and effective procedure to decompress the neural elements and obtain fixation and fusion of the fractured segment. It allows for rapid mobilisation and avoids a two-level fusion procedure with its subsequent detrimental effect on spinal biomechanics. It is considerably less invasive than anterior/lateral approaches which require extensive muscle dissection, rib removal and even diaphragmatic division.