Intraoperative Neurophysiological Monitoring in Corrective Surgery of Scoliosis - Experience at a Tertiary Care Hospital.

OBJECTIVE: To evaluate the role of intraoperative neurophysiological monitoring (IONM) in reducing the postoperative neurologic deficit following corrective surgery of scoliosis. STUDY DESIGN: Observational Study. Place and Duration of the Study: Spine Surgery Department, Combined Military Hospital, Rawalpindi, from December 2022 to May 2023. METHODOLOGY: The study included 170 cases of scoliosis operated under multimodal IONM. Decreased amplitude of ≥50% in SSEP or 70-80% in MEPs were considered warning signs. Cases were divided into two groups: Group 1 (signal drop) and Group 2 (no signal drop). Group 1 was subdivided into Group 1a (true positive), Group 1b (false positive) and Group 1c (intermediate positive). Group 2 was subdivided into Group 2a (true negative) and Group 2b (false negative). RESULTS: Evoked potential changes were observed in 27 (15.9%) cases. This includes transient drop of signals in 16 (9.4%) and sustained drop of signals in 11 (6.5%) cases. Among sustained signal drop, 9 (5.29%) cases had exhibited postoperative neurological deficit whereas 2 (1.17%) cases did not show postoperative neurological deficit (false positive). Multimodal IONM in the current study shows sensitivity of 100%, specificity of 98.6%, positive predictive value of 92.6%, and negative predictive value of 100%. CONCLUSION: Multimodal IONM reduces the incidence of postoperative neurological deficit in corrective surgery of scoliosis by effectively detecting neurologic injury during surgery. Monitoring events alert surgical team to exercise immediate corrective measures which likely results in recovery of lost signals and predict the favorable outcome. KEY WORDS: Intraoperative monitoring, Motor evoked potentials, Neurological deficit, Scoliosis, Somatosensory evoked potentials.

An experience with soft transforaminal lumbar interbody fusion in postoperative discitis not responding to conservative treatment.

OBJECTIVE: To determine the effect of soft Transforaminal Interbody Lumbar Interbody Fusion (sTLIF) in postoperative discitis not responding to conservative treatment. METHODS: This cross-sectional study was conducted in Department of Spine Surgery, CMH Rawalpindi from August 2016 to July 2019. Patients who underwent discectomy were observed and those presenting with postoperative discitis were included in the study. Pain was noted on visual analogue scale before and after the intervention and differences in two readings were noted. Data was collected on predesigned proforma. Statistical analysis was done on SPSS 20.0. RESULTS: Mean age of these patients was 45±12.34 years. The mean pain score on VAS before treatment was 8.33±0.65 and after treatment was 2±0.95. There was statistically significant reduction in pre-treatment and post-treatment pain on VAS (p=0.000). CONCLUSIONS: Postoperative discitis is present among a small number of patients after spine surgery and pain is significantly reduced after the treatment of discitis with TLIF.

Outcome of hemivertebra resection in congenital thoracolumbar kyphosis and scoliosis by posterior approach.

OBJECTIVE: To find out the long term outcome of deformity correction by hemivertebra resection in congenital thoracolumbar spinal deformities by a single posterior approach. METHODS: This is a retrospective study carried out at the Department of Spine Surgery, Combined Military Hospital, Rawalpindi, Pakistan from April 2006 to April 2013. All operated patients having single level hemivertebrae of thoracolumbar spine with at least two years follow up were included. Data was analyzed using SPSS ver. 17. RESULTS: There were 24 patients with mean age of 17 years (SD=8.41). Male to female ratio was 9(37.5%): 15(62.5%). Mean operation time was 4.23 hours (SD=1.2). Mean blood loss was 787 ml (SD=479). Mean follow up was for 5 years and 7 months (SD=30 months). Mean pre-op scoliosis was 51 degrees (SD=22), which improved to 20 degrees (SD=15) on last follow up (61% improvement). Mean pre-op kyphosis was 42 degrees (SD=35), which improved to 13 degrees (SD=15) on last follow up (69% improvement). Mean pre-op sagittal shift was 22mm (SD=24.9), which improved to 6mm (SD=9.37) on last follow up (73% improvement). Mean pre-op coronal shift was 34mm (SD=27.1), which improved to 8mm (SD=8.58) on last follow up (76% improvement). Five patients had complications. One proximal junctional kyphosis, one implant failure, one transient deficit and two wound infections. CONCLUSIONS: Posterior resection of hemivertebrae for congenital thoracolumbar deformities gives excellent correction of deformity in experienced hands and has acceptable complication rate.

Multi level lumbosacral spinal fusion including lumbo-Sacral (L5-S1) junction fixation in adult deformity surgery; is postero- lateral fusion at (L5-S1) alone adequate?

BACKGROUND/AIMS: To assess the revision rate at L5-S1 when only posterior fixation with pedicle screws is done with multi-level spinal fixation. PATIENTS AND METHODS: The Retrospective quasi experimental study was conducted at the Combined Military Hospital, Rawalpinidi and comprised data from 2009 to 2014 of patients in whom multi-level posterior decompression including lumbosacral junction (L5-S1) with laminectomy and posterior fixation with pedicle screws was done till L3 and higher. Those with known cause of implant failure like osteoporosis, osteomalacia and infection were excluded. Patients were followed up and need for revision at L5-S1 level was assessed. RESULTS: Of the 22 cases, 5(23%) were males and 17(77%) were females with an overall mean age of 64±10.38 years (range 48-84 years). Mean number of levels fixed was 5.22±1.15 the highest level of fixation being T11. Mean follow-up was 08±3.22 months and focused only at the failure of fixation at L5-S1. Two (9%) cases showed implant loosening and required revision at L5-S1 because of screw cut out. CONCLUSIONS: Properly placed pedicle screws were adequate with fusion for multilevel spinal fixations.

Surgical management of contiguous multilevel thoracolumbar tuberculous spondylitis.

INTRODUCTION: Tuberculous spondylitis (TBS) is the most common form of extra-pulmonary tuberculosis. The mainstay of TBS management is anti-tuberculous chemotherapy. Most of the patients with TBS are treated conservatively; however in some patients surgery is indicated. Most common indications for surgery include neurological deficit, deformity, instability, large abscesses and necrotic tissue mass or inadequate response to anti-tuberculous chemotherapy. The most common form of TBS involves a single motion segment of spine (two adjoining vertebrae and their intervening disc). Sometimes TBS involves more than two adjoining vertebrae, when it is called multilevel TBS. Indications for correct surgical management of multilevel TBS is not clear from literature. MATERIALS AND METHODS: We have retrospectively reviewed 87 patients operated in 10 years for multilevel TBS involving the thoracolumbar spine at our spine unit. Two types of surgeries were performed on these patients. In 57 patients, modified Hong Kong operation was performed with radical debridement, strut grafting and anterior instrumentation. In 30 patients this operation was combined with pedicle screw fixation with or without correction of kyphosis by osteotomy. Patients were followed up for correction of kyphosis, improvement in neurological deficit, pain and function. Complications were noted. On long-term follow-up (average 64 months), there was 9.34 % improvement in kyphosis angle in the modified Hong Kong group and 47.58 % improvement in the group with pedicle screw fixation and osteotomy in addition to anterior surgery (p < 0.001). Seven patients had implant failures and revision surgeries in the modified Hong Kong group. Neurological improvement, pain relief and functional outcome were the same in both groups. CONCLUSION: We conclude that pedicle screw fixation with or without a correcting osteotomy should be added in all patients with multilevel thoracolumbar tuberculous spondylitis undergoing radical debridement and anterior column reconstruction.

Tuberculosis of the craniovertebral junction.

PURPOSE: Tuberculosis (TB) of craniovertebral junction (CVJ) occurs in 1-5 % of cases of TB spondylitis. This can be a life-threatening condition due to mass effect of infective process or resultant instability. Surgical indications for TB of CVJ are not clear from literature. METHODS: We have reviewed all the patients with TB of CVJ admitted at our center between 2005 and 2010. RESULTS: There were 15 patients including 10 males and 5 females. Average age was 38 years and average duration of symptoms was 8 months. All patients were started on multidrug antituberculous chemotherapy and skull traction. Those patients who failed to respond in 4-6 weeks and had persistent instability or neurological deficit were offered surgery. Rest was treated conservatively by immobilisation or traction. All five patients who were surgically treated had occipitocervical fusion (OCF) with titanium screws and plate/rod construct combined with posterior decompression if needed. Only one patient needed anterior surgery in addition to OCF at a later stage. All patients improved neurologically whether they were treated surgically or conservatively. Only difference was that surgically treated patients had earlier pain relief, mobilisation, neurological improvement and lesser complications. CONCLUSION: We recommend that all patients with TB of CVJ with instability and neurological compromise, who fail to respond to 4-6 weeks of antituberculous chemotherapy and skull traction should be offered occipitocervical fusion with or without posterior decompression. Anterior surgery will be needed only in those few cases who do not improve neurologically after OCF.

Os-odontoideum leading to atlanto-axial instability--report of surgery in four cases.

Os odontoideum can lead to atlantoaxial instability, which can be either reducible or a fixed dislocation. We present surgical management in four patients with os odontoideum at our center. Two of these had reducible dislocations and were managed by posterior transarticular screw fixation. Other two had fixed dislocations necessitating posterior decompression and occipitocervical fixation.