Combined anterior plus posterior stabilization versus posterior short-segment instrumentation and fusion for mid-lumbar (L2-L4) burst fractures.

STUDY DESIGN

Prospective randomized study. OBJECTIVES.: To compare the results of the combined anterior-posterior surgery (Group A) with posterior "short-segment" transpedicular fixation (SSTF) (Group B) in mid-lumbar burst fractures.

SUMMARY OF BACKGROUND DATA

There are no comparative randomized clinical studies on the outcome following operative treatment of mid-lumbar fractures.

METHODS

Forty consecutive patients with L2-L4 fresh single A3-type/AO burst fractures and load sharing score up to 6 were randomly selected to underwent either combined one-stage anterior stabilization with mesh cage and SSTF (Group A) or solely SSTF with intermediate screws in the fractured vertebra (Group B). Kyphotic Gardner angle, anterior and posterior vertebral body height (PVBHr, AVBHr), spinal canal encroachment (SCE), SF-36, VAS, and Frankel classification were used.

RESULTS

The follow-up observation averaged 46 and 48 months for Group A and B, respectively. Operative time, blood loss, and hospital stay were significant more in Group A. More surgical complications were observed in the Group A. After surgery, VAS was reduced to 4.3 and 3.6 for Group A and Group B, respectively. The SF-36 domains Role physical and Bodily pain improved significantly only in Group B (P = 0.05) and (P = 0.06), respectively. Correction of AVBHr, PVBHr, and spinal canal clearance was similar in both groups. Spinal canal clearance did not differ between the two groups, but it was continuous until the last evaluation in Group B. The final Gardner angle loss of correction averaged 2 degrees and 5 degrees for Group A and Group B, respectively. The posttraumatic Gardner deformity did not significantly improve by SSTF at the final evaluation in the spines of Group B. Gardner angle correlated significantly with SCE in Group B and Group A in all three periods and in the last evaluation, respectively. Frankel grade did not correlate with loss of correction of AVBHr and PVBHr in Group A, while it significantly correlated with loss of PVBHr correction and SCE in the patients of Group B. There was no neurologic deterioration after surgery in any patient. VAS and SF-36 scores did not significantly correlate with the loss of kyphotic angle correction and AVBHr, PVBHr at the final observation in any patient of both groups.

CONCLUSIONS

SSTF offered similar significant short-term correction of posttraumatic deformities associated with mid-lumbar A3-burst fractures, but better clinical results as compared to combined surgery. However, SSTF did not significantly maintain the after surgery achieved correction of local posttraumatic kyphosis at the final evaluation. Thus, SSTF is not recommended for operative stabilization of fractures with this severity.