Background: The Universal Clamp (UC) is a novel vertebral anchor consisting of a sublaminar polyester band connected to fusion rods by a titanium jaw locked with a screw. The authors prospectively studied patients treated for thoracic or lumbar burst fractures with short pedicle screw constructs reinforced with UCs to prevent screw pullout.
Methods: Eleven patients below 18 years of age underwent 2-stage circumferential fusion for complete burst fractures (Magerl A 3.3). Two pedicle screws reinforced by 2 UCs were inserted in the vertebra proximal to the fracture and 2 pedicle screws reinforced by 2 UCs were inserted in the vertebra distal to the fracture. Within 7 days, cages filled with cancellous bone graft were added for anterior column support. T12 was fractured in 3 patients, L1 in 4, L3 in 2, and L4 in 2 patients. Preoperatively, 10 patients were neurologically intact (Frankel E) and 1 patient had an incomplete spinal cord injury (Frankel C).
Results: Mean operative duration for the posterior and anterior procedures was 110±24 and 120±35 minutes, respectively. Average intraoperative blood loss was 355±60 mL. Mean hospital stay was 11±2 days and follow-up averaged 36.1±5 months. Mean kyphotic deformity was corrected from 25±9 to 5.3±4.5 degrees postoperatively (79%), without subsequent loss of correction (P=0.17). Regional kyphosis improved by 20±8 degrees postoperatively, without subsequent loss of correction (P=0.09). No intraoperative complication was observed. There was no neurological deterioration. The patient who had a Frankel C lesion recovered 1 Frankel level (Frankel D) at final follow-up. None of the patients exhibited significant correction loss during follow-up, and there was no pseudarthrosis.
Conclusions: Thoracic and lumbar complete burst fractures in skeletally immature patients can be treated using anterior bone graft cages and posterior instrumented fusion augmented with UCs to prevent pedicle screw pullout. With these constructs, which are short to preserve mobile intervertebral segments, kyphosis was corrected, fusion achieved, and correction maintained in all subjects without neurological worsening.
Level of Evidence: Level IV.