Comparison of anterior instrumentation systems and the results of minimum 5 years follow-up in the treatment of tuberculosis spondylitis.

Anterior debridement, strut grafting and instrumentation have an increasing popularity in the treatment of tuberculosis of spine. Anterior fixation can be done either by a plate or a rod system. This study reports on the surgical results of 59 patients with Pott's disease that had anterior radical debridement and anterior fusion and anterior instrumentation with 5 years follow-up. Average age at the time of operation was 46.3+/-13.5 years. Average follow-up was 84.6+/-11.3 months. Local kyphosis was measured as the angle between the upper and lower end plates of the collapsed vertebrae preoperatively, postoperatively and at the last follow-up visit. Vertebral collapse, destruction, cold abscess, and canal compromise were assessed in MR images. The indication for surgery was either one of the deformity, instability or neurological compromise. Surgical treatment included anterior radical debridement followed by grafting with tricortical auto graft and anterior instrumentation at levels just above and below the diseased segment(s) with either plate (Sofamor-Danek, Z plate, Group A) or rod (Sofamor-Danek, CDH, Group B) systems. There were 23 patients in group A and 36 patients in group B. All patients had similar anti tuberculosis chemotherapy. Patients had similar rehabilitation program after the surgery. The deformity in the sagittal and the coronal plane was measured and presence of significant consolidation, along with the absence of implant failure or correction loss was considered as signs of fusion. The two groups were similar according to age (46.9+/-14.2 vs. 45.8+/-13.1), gender, average number of involved levels (1.8+/-0.5 vs. 1.6+/-0.5), location of involved levels, severity of deformity (21.5 degrees+/-9.9 masculine vs. 24.8 degrees+/-11.9 masculine) and type of autografts (p>0.05 for all parameters). 39.1 % of patients in group A and 41.6 % of patients in group B had neurological compromise with improvement in majority at the end of follow-up. Deformities were corrected to 5.2 degrees+/-5.7 masculine in group A and 6.1 degrees+/-6.8 masculine in group B with no significant difference. At the time of latest follow-up there were 1.7 degrees+/-2.0 masculine correction loss in group A and 1.4 degrees+/-1.9 masculine in group B with no significant difference in between two groups (p>0.05). Overall, it was observed that, the addition of anterior instrumentation increased the rate of correction of the kyphotic deformity (78.5+/-20.5%), and was effective in maintaining it with an average loss of 1.5 degrees+/-1.9 degrees. Of the 24 (44.1%) patients with neurological symptoms, 20 (83.3%) had full and 4 (16.7%) partial recoveries. There was no apparent pseudoarthrosis and implant failure in both groups and all patients demonstrated clinical improvement in tuberculosis infection without recurrences and reactivation. Four major complications occurred in the group A (major vessel complication: 3.4%, secondary non-specific infection: 3.4%). Disease reactivation was not seen with the employment of an aggressive chemotherapy regimen. It was concluded that anterior instrumentation is a safe and effective method in the treatment of tuberculosis spondylitis. There were no significant differences between the two instrumentation systems in terms of sagittal alignment reconstruction and fusion rate. In rod-screw systems, the disadvantages of scoliotic deformity correction through frontal plan in plate performing did not occur and it is though to have the advantage of long instrumentation in multiple level deformities.