DOI: 10.1097/BRS.0000000000000618 TO THE EDITOR: Re : He B, Yan L, Guo H, et al. The Difference in Superior Adjacent Segment Pathology After Lumbar Posterolateral Fusion by Using 2 Different Pedicle Screw Insertion Techniques in 9-Year Minimum Follow-up. Spine (Phila Pa 1976) 2014;39:1093–8. We read with interest the recent article “The difference in superior adjacent segment pathology after lumbar posterolateral fusion by using 2 different pedicle screw insertion techniques in 9-year minimum followup” by He et al . 1 The authors are to be congratulated on designing this simple randomized control trial study to provide strong evidence that a more lateral starting point results in less radiographical and clinical adjacent segment disease (ASD). However, we think that the study still has some limitations. Sagittal alignment has been shown in some studies 2–4 to infl uence adjacent level degeneration after lumbar or cervical fusion, which is one of the most important proposed surgical risk factors for ASD. However, there is no information about the sagittal parameters of each group in this article. Whether the sagittal malalignment is the causative factor for ASD or just the screw insertion technique can only be determined by also measuring the preoperative parameters for sagittal alignment and comparing the changes over time between each group. However, this comparison was not conducted by the authors of this study. The patient-selection and surgical intervention in this study might also have an enlarged and amplifi ed effects of screw insertion techniques on ASD, which could also help explain why their ASD rate (61.5%) was signifi cantly higher than others. 2–5 First, this prospective study includes 210 patients with low grade isthmic spondylolisthesis, these patients inherently, have a greater loss of disc height, and consequently, some loss of lordosis, which have more chance to be sagittal malalignment. Second, surgical decompression intervention they used is “removal of the spinous process and bilateral laminectomy, and partial bilateral foraminotomy,” which means the posterior ligament complex of the superior adjacent segment is completely removed. According to the tension band mechanism, loss of posterior ligament complex is another risk factor for adjacent segment degeneration. Third, the restoration of sagittal balance after spinal reconstruction has been identifi ed as an increasingly important risk factor for subsequent degeneration at adjacent levels. 6 Nevertheless, the authors did not mention any surgical technique for spondylolisthesis reduction procedures, nor use interbody fusion (just posterior lateral fusion instead), in these circumstances, we can only speculate there will not be any signifi cant improvement of sagittal imbalance, if it does exist.

Objective To investigate operative approach,immobilization manner,and surgical effect of multiple-level contiguous thoracic spinal tuberculosis.Methods Between January 2001 and December 2010,112 patients with thoracic spinal tuberculosis were treated with 5 different surgical procedures.Among them,81 adults with multiple-level contiguous thoracic spinal tuberculosis were followed up for 17 to 75 months (average,39 months).Twenty three patients suffered from spinal cord dysfunction; according to the Frankel classification,there were 3 cases of type A,4 cases of type B,7 cases of type C,and 9 cases of type D.The double vertebral bodies were commonly affected areas,especially T10 and T11-Results Local symptoms of all patients were relieved significantly 1 to 3 weeks postoperatively.Erythrocyte sedimentation rates (ESR) returned to normal level in all patients 8 to 12 weeks postoperatively.Three sinuses were found 0.5 month,1 month and 1.5 months postoperatively,respectively,which were cured by changing dressing for 1 to 2 months.The average correction of kyphotic deformity was 10.2°±2.1° in anterior fixation group,while 12.6°±2.7° in posterior fixation group.At final follow-up,the average loss of correction was 6.9°±1.9° in anterior fixation group,while 5.8°±1.4° in posterior fixation group.At least one Frankel grade improvement was observed in 23 patients.Conclusion The surgical methods should be chosen according to the location and degree of the lesion.Correct surgical procedures can obtain good results in correction and maintenance of the deformity,clearance of the foci,decompression of the spinal cord and pain relief for thoracic spinal tuberculosis.The posterior fixation is better than the anterior fixation with regard to correction and maintenance of the kyphotic deformity.

Objective:To investigate the surgical procedures and their outcomes for spinal tuberculosis(TB) in adults.Method:Between January 2004 and December 2009,241 adult patients with thoracolumbar and lumbosacral TB undergoing different surgical procedures were reviewed retrospectively.A total of 181 patients with multiple-level continuous spinal TB were followed up for 22-72 months(mean,37 months).Of 25 patients with neurological deficit,there were 14 Frankel D and 11 Frankel C.The involved vertebrae included 4 continuous vertebrae in 11(thoracic),3 continuous vertebrae in 45,2 continuous vertebrae in 98,and 1 vertebra in 27 cases.It showed obvious defect in 132 patients and paraspinal abscess in 153 cases by CT and MRI examination.The kyphosis Cobb angle ranged from-23° to 30° in 104 cases,31° to 60° in 49 cases and 61° to 70° in 28 cases.Erythrocyte sedimentation rates(ESR) raised in 169 cases.All patients were divided into 4 groups according to site and extent of the lesion.Group A included 74 cases who underwent anterior radical debridement and instrumentation.Group B included 70 cases who underwent posterior instrumentation and interlaminar bone graft plus anterior radical debridement and strut graft either by one-stage or two-stage.Group C included 10 cases who underwent front side radical debridment,strut graft and posterior instrumentation in thoracic or thoracolumbar spine.Group D included 27 cases who underwent single-stage posterior debridement and instrumentation.Emergency surgery was performed in 25 patients with neurological impairment following short term chemotherapy prior 6-18h before surgery.The chemotherapy medicine was administered to the remaining 156 cases over 3 weeks before surgery and continued till 12 months after operation.Result:The average operation time and blood loss were 3.5h and 450ml in group A,4.5h and 640ml in group B,3.0h and 350ml in group C and group D.Severe complications were not noted in each group.ESR returned to normal 8-12 weeks after operation.Kyphosis was corrected by(47.5±11.8)% in group A,(61.5±18.6)% in group B,(58.7±15.9)% in group C and(59.9±17.4)% in group D,with loss of correction at final follow-up of(64.8±19.3)% in group A,(53.6±15.6)% in group B,(56.9±11.8)% in group C and(54.9±15.4)% in group D.And at final follow-up,18 cases had Frankel level improved 1 level,and 7 cases had it improved 2 levels.Sinus was found in the each of Group A,B and C at half a month,one month and one and a half months respectively,which was healed by proper intervention 1-2 months later.Instrument loosening was found in 1 patient of group A one year later,however no intervention was performed due to evidenced fusion.No recurrence was observed at final follow-up in all groups.Conclusion:Different surgical approaches are indicated for debridement,decompression and kyphosis correction,which are reliable for spinal tuberculosis.Posterior approach is superior than anterior approach due to its deformity correction and maintaining of correction.