Non-structural Inter-body Fusion For Treatment Of Thoracic And Lumber Spinal Tuberculosis;Via A Posterior-only Approach

Study design:A retrospective study.Background:Spine deformity and paralysis due to spinal tuberculosis are the most significant complications associated with this disease.Several spine reconstructive techniques have been reported in literature including,using nonstructural and structural interbody fusion techniques.However,few studies have compared these methods,with usage of combined morselized auto/ allogeneic bone graft.Objective:We aim to compare and evaluate the efficacy and safety of non-structural versus structural inter-body fusion,using a combination of auto-graft and allograft bone for treatment of thoracic and lumber spine tuberculosis via a posterior-only approach.Methods:Between March 2015 and December 2017,we retrospectively analysed,117 patients treated for thoracic and lumber spine tuberculosis at the orthopaedic-spine department of the China-Japan Union Hospital of Jilin University.However,only 37 patients were included in our study,after meeting the inclusion criteria.All patients underwent posterior-only approach with pedicle screw instrumentation using a mixture of morselized allograft and auto-graft.Eighteen patients underwent nonstructural inter-body fusion(Group A)while 19 had structural interbody fusion with aid of titanium mesh cages(Group B).We compared and analysed;blood loss,operation time,neurological involvement,bone fusion rates,and correction angles.Results:The average follow-up period was 20.33±4.73 months(range 12-26)and19.63±4.63 months(range 12-26),in group A and B respectively.All patients showed significant improvement in neurological impairment scale(ASIA)by 1-2 grades.Preoperatively in Group A,patients were graded as follows: 1 patient grade B,6patients grade D and 11 patients grade E.Improved postoperatively to 1 patient grade C,2 patients grade 2 and 15 patients grade E.While in Group B preoperatively 2patients grade C,7 patients grade D and 11 patients grade E.Improved significantly,postoperatively to 3 patients grade D and 16 patients grade E.Bone fusion was achieved in all patients,at an average time of 6.17±1.38 months(range 4 – 9)and 7.58 ± 2.41 months(range 4 – 12),in Group A and B respectively,no statistical significance among groups(P>0.05).There were significant differences in operation duration and blood loss,196.28 ± 43.49 min(range 128-300)and 223.26± 46.34 min(range 150-300),474.44 ± 224.37 ml(range 200-900)and 585.79 ±378.82 ml(range 200-1500),in group A and B respectively(P<0.05).Loss of correction was 3.52° and 2.41°,in group A and B respectively.Conclusion:Our results demonstrate that nonstructural inter-body fusion using morselized allograft and auto-graft is not only effective but is a safe technique for treatment of spinal tuberculosis,when used with a single-staged posterior-only approach and instrumentation.