Rotational stability of thoracolumbar junction fixation systems

Objective To compare the rotational stability of fusion constructs using bisegmental fixation of Th12-L2 vertebrae with anterior stabilization or pedicle screw fixation.Material and Methods The strength, rigidity and limit of elasticity in the “injured vertebral motion segments (VMS) – bisegmental anterior stabilization” system under dislocating rotational loads were estimated. The data obtained were compared with the similar characteristics of the “injured VMS – bisegmental 4-screw transpedicular metal construction” system and intact spine segments.Results Under rotational loads the limits of elasticity of injured spine segments of Th12-L2 with anterior stabilization and transpedicular screw fixation (TSF) is 45.5 and 41.7%, respectively, and the general strength is 66.4% and 80%, respectively, as compared with those intact VMS. Rigidity parameters of anterior-stabilized and pedicle screw fixated VMS with unstable damage of L1 are 60.2 and 93.9%, accordingly, in comparison with those intact VMS.Conclusion No significant differences were observed between bisegmental anterior stabilization and bisegmental pedicle screw fixation of thoracolumbar junction in terms of the key mechanical properties. When treating patients with unstable thoracolumbar spine injuries using bisegmental anterior stabilization or transpedicular fixation with 4-screw spinal system possible rotation motion amplitude of operated segments must not exceed 50% of maximum physiological limits.

Clinical effect of a novel transpedicular reducer for reduction and bone grafting combined with pedicle screw fixation for thoracolumbar burst fractures

Background Short-segment transpedicular screw fixation is a common method for the treatment of thoracolumbar burst fractures (TBFs),but this technique has many problems. Therefore,the purpose of this article is to observe and evaluate the clinical efficacy of a novel transpedicular reducer that we designed for fractured vertebral body reduction and bone grafting in the treatment of TBFs. Methods From July 2018 to November 2020, 70 cases of TBFs were included. Thirty-five patients were treated with the novel transpedicular reducer for reduction and bone grafting combined with pedicle screw fixation (observation group), and 35 patients were treated with short-segment transpedicular screw fixation (control group). Before the operation, after reduction, and 3 days, 3 months,and 12 months after the operation, the two groups were assessed, and compared with respect to the anterior and middle heights of the injured vertebrae, the ratios of the anterior and middle heights of the injured vertebral body to the respective heights of the adjacent uninjured vertebral bodies (AVBHr and MVBHr, respectively), and the Cobb angle of the patients. We compared the pain VAS score and quality of life GQOL-74 score at the last follow-up. Finally,we evaluated the distribution of bone grafts and bone healing 12 months after the operation. Results The anterior height, middle height, AVBHr, MVBHr, and Cobb angle of the injured vertebral body in the observation after reduction, and 3 days, 3 months and 12 months post-operatively were compared with those of the injured vertebral body before operation. All of these parameters were improved, and the difference was statistically significant (p < 0.05). These parameters in the observation group at the above time points were significantly better than thoes in the control group at the corresponding time points (p < 0.05). The VAS scores at the last follow-up were significantly better than those of the control group (p < 0.05), but the GQOL-74 score differences were not statistically significant (p > 0.05). The observation group showed no obvious defects on CT at 12 months after the operation, and the bone healing was good. Conclusion The novel transpedicular reducer for reduction and bone grafting combined with pedicle screw fixation for TBFs has good clinical efficacy.

Surgical outcomes of decompression alone versus transpedicular screw fixation for upper lumbar disc herniation

Background Surgical outcomes of upper lumbar disc herniations (ULDHs) including T12-L1, L1-L2, and L2-L3 levels are characteristically less favorable and more unpredictable. Objectives This study was conducted to compare the surgical outcomes of decompression alone versus decompression combined with transpedicular screw fixation in treating upper lumbar disc herniation. Methods This retrospective cohort study was carried out at Neurosurgery Departments, Tanta University. The study included 46 patients with a symptomatic high lumbar herniated disc at T12-L1, L1-L2, and L2-L3 levels. The enrolled patients were divided into two groups depending on whether they were operated on via decompression and partial medial facetectomy (group 1, 22 patients) or via the previous maneuver plus transpedicular screw fixation (group 2, 24 patients). All patients were medically evaluated immediately after the operation; then, they were followed up at the 3rd and the 6th months following surgery. Patients’ outcomes were assessed by visual analogue score (VAS) and Oswestry Disability Index (ODI) scores. Results Median VAS scores in each group revealed significant reduction immediately following surgery and at each of 7 days, 3 months, and 6 months in comparison with the preoperative VAS score (p<0.001). Furthermore, each group showed significant stepwise reduction in the median ODI score at the 3rd and the 6th months postoperative compared to the preoperative ODI score (group 1 = 68.0, 19.0, 15.0; p< 0.001 and group 2 = 66.5, 20.0, 15.0; p< 0.001), with no significant differences between both groups (p> 0.05). Conclusions Both standalone decompression and decompression combined with transpedicular screw fixation revealed comparable favorable outcomes in patients with ULDH.

Comparison of MRI Visualization Following Minimally Invasive and Open TLIF: A Retrospective Single-Center Study

Analysis of magnetic resonance image (MRI) quality after open (Op)-transforaminal interbody fusion (TLIF) and minimally invasive (MI)-TLIF with the implantation of structurally different systems has not previously been performed. The objective of this study was to conduct a comparative analysis of the postoperative MRI following MI and Op one-segment TLIF. Material and Methods: The nonrandomized retrospective single-center study included 80 patients (46 men and 24 women) aged 48 + 14.2 years. In group I (n = 20) Op-TLIF with open transpedicular screw fixation (TSF) was performed, in II group (n = 60), the MI-TLIF technique was used: IIa (n = 20)—rigid interspinous stabilizer; IIb (n = 20)—unilateral TSF and contralateral facet fixation; IIc (n = 20)—bilateral TSF. Results: Comparison of the quality of postoperative imaging in IIa and IIb subgroups showed fewer MRI artifacts and a significantly greater MR deterioration after Op and MI TSF. Comparison of the multifidus muscle area showed less atrophy after MI-TLIF and significantly greater atrophy after Op-TLIF. Conclusion: MI-TLIF and Op-TLIF with TSF have comparable postoperative MR artifacts at the operative level, with a greater degree of muscle atrophy using the Op-TLIF. Rigid interspinous implant and unilateral TSF with contralateral facet fixation have less artifacts and changes in the multifidus muscle area.

Hidden blood loss and its influencing factors after minimally invasive percutaneous transpedicular screw fixation in thoracolumbar fracture

Objective: This study aimed to investigate the amount of hidden blood loss (HBL) and its influencing factors after minimally invasive percutaneous transpedicular screw fixation (MIPTSF) in thoracolumbar fracture.Summary of Background Data: MIPTSF is generally accepted as a minimally invasive treatment for thoracolumbar fracture. However, HBL caused by this procedure is usually disregarded.Materials and Methods: Between October 2017 and December 2020, a total of 146 patients (106 males and 40 females, age range 21–59 years) were retrospectively examined, and their clinical and radiological data were recorded and analyzed. The Pearson or Spearman correlation analysis was used to investigate an association between patient’s characteristics and HBL. Multivariate linear regression analysis was performed to elucidate the related clinical or radiological factors of HBL.Results: A substantial amount of HBL (164.00 ±112.02 ml, 40.65% of TBL) occurred after transpedicular screw internal fixation. Multivariate linear regression analysis revealed that HBL was positively associated with total blood loss (TBL) (P=.000), percentage of vertebral height loss (VHL) (P=.000), percentage of vertebral height restoration (VHR) (P=.000), numbers of fractured vertebrae (P=.013), and numbers of fixed vertebral segments (P=.002).Conclusion: A large amount of HBL was incurred in patients undergoing MIPTSF in thoracolumbar fracture. More importantly, TBL, percentage of VHL, percentage of VHR, the numbers of fractured vertebrae and fixed vertebral segments were independent risk factors for HBL.

Clinical effect of a new type of transpedicular reducer for fracture reduction via pedicle and bone grafting combined with pedicle screw fixation for thoracolumbar burst fractures

Background: Short-segment transpedicular screw fixation is a common method for the treatment of thoracolumbar burst fractures (TBFs),but this technique has many problems.Therefore,the purpose of this article is to observe and evaluate the clinical efficacy of a new type of transpedicular reducer that we designed for fractured vertebral body reduction and bone grafting in the treatment of TBFs.Methods:From July 2018 to November 2020, 70 cases of TBFs were included. 35 cases were treated with the new transpedicular reducer for fracture reduction via pedicle and bone grafting combined with pedicle screw fixation (observation group), 35 cases were treated with short-segment transpedicular screw fixation (control group).Before operation, after application of the transpedicular reducer(not needed in the control group),3 days after operation, 3 months after operation, 6 months after operation, and 12 months after operation, the two groups were recorded and compared respectively: the anterior and middle heights of the injured vertebrae, the ratios of the anterior and middle heights of the injured vertebral body to the respective heights of the adjacent uninjured vertebral bodies (AVBHr and MVBHr, respectively), and the Cobb angle of patients.And we compared the pain VAS score and quality of life GQOL-74 score at the last follow-up.At last,we evaluated the distribution of bone grafts and bone healing 12 months after the operation.Results:All 70 cases were followed up for at least 12 months.The observation group's anterior and middle heights of the injured vertebral, AVBHr and MVBHr were higher than those of the control group at 3 days,3 months,6 months and 12 months after operation, the cobb angle was smaller than that in control group, the pain VAS score and the quality of life GQOL-74 score at the last follow-up were better than those of the control group, and these difference were statistically significant (P <0.05). The observation group showed no obvious defects on CT at 12 months after operation, and the bone healing was good. Conclusion: The new type of transpedicular reducer for fracture reduction via pedicle and bone grafting combined with pedicle screw fixation for TBFs has a good clinical efficacy.

Pedicular lumbosacral spine fusion for adult/adolescent lumbar developmental high-grade spondylolisthesis

Background: Few series report on the management of high-grade spondylolisthesis (HGS) in adolescents and young adults. This review highlights a series of six consecutive cases with developmental (dysplastic) HGS successfully managed with L3 or L4 to S1 transpedicular screw placement, rather than in situ/noninstrumented lumbosacral fusion. Methods: The six patients with HGS, according to the Meyerding Grading, presented with low back pain and bilateral sciatica (2016–2020). Patients averaged 19.8 years of age and underwent posterior transpedicular L3 or L4-S1 screw fusions. They were all monitored for at least 6 postoperative months. Results: None of the six patients developed any major perioperative/postoperative complications; only one patient had severe postoperative back pain that slowly improved over 3 months. All the patients were clinically improved postoperatively, uniformly demonstrated fusion on postoperative CT studies, and considered the operation worthwhile. Conclusion: Posterior transpedicular screw fixation of the lumbosacral spine is an efficient and safe technique for the treatment of L3 or L4 to L5-S1 HGS. It is a suitable instrumented technique for managing adult/adolescent HGS and offers an alternative to the more typically performed in situ/noninstrumented L4-S1 procedures.

Evaluation of Outcome of Decompression and Transpedicular Screw Fixation in the Management of TB of the Thoracolumbar Spine

Introduction: Spinal tubercular infection is the most common and dangerous form of skeletal tuberculosis. Transpedicular instrumentation systems have distinct advantages such as rigid segmental fixation, stabilization of the three column of the spine, least failure at bone metal interface, early post-operative mobilization with efficient nursing care and least complications in the management of tuberculosis of the thoraco-lumbar spine. Objectives was to evaluate the outcome of decompression and transpedicular screw fixation in the management of tuberculosis of the thoracolumbar spine. Materials and Methods: An observational follow-up study. A total no. of 21 patients aged between 19-72 years and both sexes (Male-9, Female-12) was included in the study. Patients diagnosed as tuberculosis of the thoraco-lumbar spine were operated by direct decompression, transpedicular screw fixation and fusion with bone graft and mesh cage in some cases. First follow-up at 1 month after operation and thereafter at 3 and 6 months follow-up was done. Results: This study shows mean±SD age was 40±11.29 years. 57.1% were female and 42.9% were male. Lesion 66.7% were dorsal, 19.0% were lumbar and 14.3% were dorsolumbar. 42.86% were ASIA grade C, 33.33% were ASIA grade D, 9.52% were both ASIA grade B & E and 4.76% were ASIA grade A in preoperative stage. On the other hand in postoperative 61.90% were ASIA grade E, 33.33% were ASIA grade D and 4.76% were ASIA grade B. The difference was statistically significant (P<0.001). Four-fifths (80.95) of the patients had excellent outcome followed by 14.29% good outcome, 4.76% fair and 0% poor outcome. Conclusions: Posterior approach is a minimum surgical intervention that encourages neurological recovery. Medicine Today 2020 Vol.32(2): 104-111