Subsidence of thoracolumbar burst fractures after rod long/fuse short technique

Objective: One alternative for the surgical treatment of thoracolumbar burst fractures (TLBF) is the rod long/fuse short (RLFS) technique utilizing the Harrington Distraction Rods (HDR) system. The height of the fractured vertebral body usually returns to approximately normal values immediately after the surgery, but some months later, this gain is lost (subsidence). Our objective is to verify the clinical and radiological outcome with the RLFS technique with Universal Instrumentation (UI). Methods: Twelve cases of TLBF (Male/Female=9/3, mean age=35.7 y.o., Frankel grades: E=9, C=3) were treated. Through a posterior approach, UI was placed two levels above and two below the fractured vertebra. Bone grafts were placed from one level above to one level below the fracture. After at least nine months, the rod was cut and the hardware located beyond the grafted area was removed. Clinical results were measured by Frankel scale and the SF-36 Form. Radiographic parameters (Cobb's angle, anterior and posterior heights of the fractured vertebra) were measured in three moments: pre-operative, immediate post-operative and after hardware removal. Statistical analysis was performed with analysis of variance -ANOVA (alpha=0.05) and Pearson's "r" test (p<0.05). Results: No neurological deterioration was observed. All neurologically compromised patients, except one, improved one Frankel grade. Radiographic parameters improved after the first surgery, but this improvement was reduced after hardware removal. Post-operative kyphosis negatively interfered in the quality of life of our patients. Conclusion: When the RLFS is chosen to treat a TLBF, the utilization of UI does not show advantage over HDR in terms of clinical and radiological outcome.