Implant removal after percutaneous short segment fixation for thoracolumbar burst fracture : does it preserve motion?

Abstract

Objective: The purpose of this study was to evaluate the efficacy of implant removal of percutaneous short segment fixation after vertebral fracture consolidation in terms of motion preservation.

Methods: Between May 2007 and January 2011, 44 patients underwent percutaneous short segment screw fixation due to a thoracolumbar burst fracture. Sixteen of these patients, who underwent implant removal 12 months after screw fixation, were enrolled in this study. Motor power was intact in all patients, despite significant vertebral height loss and canal compromise. The patients were divided into two groups by degree of osteoporosis : Group A (n=8), the non-osteoporotic group, and Group B (n=8), the osteoporotic group. Imaging and clinical findings including vertebral height loss, kyphotic angle, range of motion (ROM), and complications were analyzed.

Results: Significant pain relief was achieved in both groups at final follow-up versus preoperative values. In terms of vertebral height loss, both groups showed significant improvement at 12 months after screw fixation and restored vertebral height was maintained to final follow-up in spite of some correction loss. ROM (measured using Cobb's method) in flexion and extension in Group A was 10.5° (19.5/9.0°) at last follow-up, and in Group B was 10.2° (18.8/8.6°) at last follow-up. Both groups showed marked improvement in ROM as compared with the screw fixation state, which was considered motionless.

Conclusion: Removal of percutaneous implants after vertebral fracture consolidation can be an effective treatment to preserve motion regardless of osteoporosis for thoracolumbar burst fractures.

Keywords: Fusion; Percutaneous; Removal.

Fig. 1

Restoration of vertebral height.

Fig. 2

A case of a neurologically intact 29-year-old woman with a L1 burst fracture (Group A). A, B, and C : Preoperative simple radiograph and computed tomography images showing about 40% height loss and 50% canal compromise. D, E, and F : Simple radiographs and a computed tomography image taken at 12 months after percutaneous screw fixation showing consolidation of the fractured body and improved kyphosis. G and H : Simple flexion and extension radiographs taken at 11 months after screws removal revealing well-maintained range of motion, which coincided with a completely pain free status.

Fig. 3

A case of a neurologically intact 72-year-old woman with a L1 burst fracture (Group B). A and B : Preoperative simple radiograph and computed tomography image showing about 60% height loss. C, D, and E : Simple radiographs and a computed tomography image taken at 12 months after percutaneous screw fixation showing consolidation of the fractured body and restored vertebral height. F and G : Simple flexion and extension radiographs taken at 13 months after screw removal reveal a well-maintained range of motion, which coincided with a completely pain free status.