Surgical treatment of thoracolumbar tuberculosis: a retrospective analysis of autogenous grafting versus expandable cages

There has been no uniform and extensive description of the use of expandable cages in the setting of thoracolumbar tuberculosis. The purpose of the study was to evaluate the results of the expandable cages and compare with autogenous strut grafting in thoracolumbar tuberculosis.

From January 2003 to January 2014, a total of 28 patients with thoracolumbar tuberculosis were treated surgically in our medical center. Patients were divided into three groups. 17 patients received anterior-only surgery; consisting of autogenous iliac bone grafting only in 9 (Group 1), grafting with anterior screw-rod system instrumentation after debridement in 8 patients (Group 2). 11 patients underwent anterior surgery including debridement and distraction of the kyphosis by cages after corpectomy following posterior instrumentation (Group 3).The changes in degree of kyphotic deformity, loss of correction, intervertebral height and loss of intervertebral height were evaluated preoperatively, postoperatively and at the final follow-up.

Patients were followed 52 ± 10.7 months (range, 18–120 months). Mean age in the Group 1 was 42 (18–69) years, 62 (19–86) years in the Group 2 and 51 (19–71) years in the Group 3. There was no statistically significant difference (P > 0.05) in the focal kyphosis preoperatively, postoperatively and at the last follow-up between three groups. There were statistically significant differences (P < 0.05) in loss of correction, intervertebral height (preoperative, postoperative and final follow-up) and loss of intervertebral height between three groups. There was a greater loss of correction in Group 1 when compared with Group 2 and Group 3. The difference was statistically significant (p < 0.001). There was no statistically significant difference in the intervertebral height postoperatively and follow-up between Group 1 and Group 2. There was a significant increase in the intervertebral height in Group 3 when compared with Group 1 and Group 2. There was also a significant increase in the intervertebral height in Group 2 when compared with Group 1. There was a greater loss of intervertebral height in Group 1 than in Group 2 and Group 3. The difference was statistically significant (p < 0.001).

Expandable cages are an acceptable surgical option for the treatment of thoracolumbar tuberculosis. Sagittal alignment is better prevented with the expandable cages than anterior grafting with or without anterior instrumentation. Subsidence of the expandable cages is not uncommon and results in the loss of Cobb angle correction and intervertebral height. However, anterior vertebral column reconstruction by expandable cages provides a very high and effective rate of deformity correction and maintenance.