Objective To investigate the feasibility and clinical outcomes of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using unilateral incision and internal fixation of pedicle screws and a translaminar facet screw for dural-level lumbar degenerative disease. Methods Between January 2010 and January 2012, 19 patients with dural-level lumbar degenerative disease was treated, including 7 males and 12 females with an average age of 50.4 years (range, 22-68 years) and a median disease duration of 37 months (range, 8 months to 15 years). The operated segments included L3-5 in 6 cases and L4-S1 in 13 cases. MIS-TLIF was performed by unilateral incision, and then pedicle screws and a translaminar facet screw were used for internal fixation. Results Operations were successfully performed in all cases. The mean operation time was 158 minutes; the mean intraoperative blood loss was 156 mL; the mean length of incision was 42 mm; the mean postoperative ambulation time was 35 hours; the mean hospitalization time was 4.1 days; and the mean length of translaminar facet screw was 51 mm. All the wounds healed by first intention. No complication occurred in the others except 1 case of dural tear. The patients were followed up 12-24 months (mean, 17.1 months). The visual analogue scale (VAS) scores for back and leg pain and Oswestry disability index (ODI) scores at postoperation were significantly improved when compared with preoperative ones (P lt; 0.05). The symptom disappeared gradually. The postoperative X-ray images showed that the internal fixations were in good position; all facets screws penetrated through the base of spinous process, laminar, and facets joint; of the screws, 2 (5.3%) facets screws penetrated lateral laminar, and 1 (1.8%) pedicle screw penetrated out of pedicle of vertebral arch, but no symptom of nerve injury was seen. The CT scan and three-dimensional reconstruction at postoperative 12th month showed good interbody fusion; and based on the Bridwell’s interbody fusion grading system, 11 cases were rated as grade I, and 8 cases as grade II. Conclusions MIS-TLIF by unilateral incision and internal fixation is a safe and reliable method to treat dural-level lumbar degenerative disease, and it has the advantages of short operation time, less invasion, less blood loss, and fast recovery.
Based on the surgical model using transforaminal lumbar interbody fusion (TLIF) to treat lumbar spondylolisthesis, this paper presents the investigations of the biomechanical characteristics of cage and pedicle screw in lumbar spinal fusion implant fixed system under different combinations with finite element method. Firstly, combining the CT images with finite element pretreatment software, we established three dimensional nonlinear finite element model of human lumbar L4-L5 segmental slight slippage and implant under different fixed combinations. We then made a comparison analysis between the biomechanical characteristics of lumbar motion range, stress distribution of cage and pedicle screw under six status of each model which were flexion, extension, left lateral bending, right lateral bending, left axial rotation and right axial rotation. The results showed that the motion ranges of this model under different operations were reduced above 84% compared with those of the intact model, and the stability of the former was improved significantly. The stress values of cage and pedicle screw were relatively larger when they were fixed by single fusion device additional unilateral pedicle screw, but there was no statistically significant difference. The above research results would provide reference and confirmation for further biomechanics research of TLIF extracorporal specimens, and finally provide biomechanical basis for the feasibility of unilateral internal fixed diagonal intervertebral fusion TLIF surgery.
ObjectiveTo compare the effect of intravenous 20% mannitol or dexamethasone (DM) on low back and leg pain after minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). MethodsBetween October 2012 and September 2013, 100 patients with degenerative lumbar diseases underwent MI-TLIF and percutaneous pedicle screw fixation. All patients were randomly divided into 3 groups:34 patients received intravenous 20% mannitol after operation (mannitol group); 32 patients received intravenous DM after operation (DM group); and 34 patients received neither dehydrating agent nor steroid after operation (control group). There was no significant difference in gender, age, disease duration, clinical symptoms, lesion types, and lesion segments between groups (P>0.05). The serum levels of inflammatory factors[tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6] were measured by ELISA at pre-operation and 3, 24, 48, 72, and 96 hours after operation. Low back and leg pain was determined by using visual analogue scale (VAS) score after operation. ResultsAll procedures were smoothly performed without major complications of nerve root injury, hematoma, or infection. There was no significant difference in operation time and intraoperative blood loss between groups (P>0.05). The VAS score of low back pain showed no significant difference between groups at all time points after operation (P>0.05); the VAS score of leg pain in the DM group was significantly lower than that in the control group at all time points (P<0.05), and than those in the mannitol group at 3, 24, 48, and 96 hours after operation (P<0.05). The serum level of TNF-α in the DM group was significantly lower than that in the control group at all time points (P<0.05), and than that in the mannitol group at 3, 48, 72, and 96 hours after operation (P<0.05). The serum level of IL-1β in the DM group was significantly lower than that in the control group at 3, 24, 48, and 72 hours after operation (P<0.05), and than that in the mannitol group at all time points after operation (P<0.05). The serum level of IL-6 in the DM group was significantly lower than that in the control group at 3 and 24 hours after operation (P<0.05), and than that in the mannitol group at 3, 24, and 48 hours after operation (P<0.05). ConclusionIntravenous 20% mannitol may has no effect on postoperative low back and leg pain, while DM can markedly relieve leg pain after MI-TLIF.
ObjectiveTo compare the effectiveness and imaging features between implanting single and double Cage into intervertebral body through unilateral transforaminal lumbar interbody fusion (TLIF). MethodsThe clinical data were collected and analyzed from 104 patients who underwent unilateral TLIF between January 2013 and October 2014, who were divided into 2 groups:single Cage was implanted into intervertebral body in 64 cases (76 segments) in traditional group, and double Cage was implanted into intervertebral body in 56 cases (70 segments) in reformative group. There was no significant difference in age, gender, bone mineral density, operation segments between 2 groups (P>0.05). The visual analogue scale (VAS), Oswestry disability index (ODI), and Japanese Orthopedic Association (JOA) scores were used to evaluate the effectiveness; the area of intervertebral bone-graft, fusion rate, height of intervertebral space, and the number of Cage subsidence were measured by CT scan. ResultsAll the patients were followed up 12.85 months on average (range, 9-15 months). The VAS, ODI, and JOA scores were significantly improved at each time point after operation when compared with preoperative values (P<0.05), and no significant difference was found between 2 groups (P>0.05) except VAS and ODI at 12 months after operation (P<0.05). However, the area of intervertebral bone-graft in reformative group[(5.94±1.17) cm2] was significantly larger than that in traditional group[(4.81±0.97) cm2] at 7 days after operation (t=-6.365, P=0.000). At 3 and 12 months after operation, the fusion rate was respectively 84.2% and 92.1% in traditional group and was respectively 88.6% and 94.3% in reformative group. Although the height of intervertebral space were increased when compared with preoperative height, the incidence rates of Cages subsidence in traditional group were 44.74% and 47.37% respectively at 3 and 12 months after operation and were significantly higher those that in reformative group (11.43% and 14.29% respectively) (P<0.05). In addition, the height difference between affected side and normal side in traditional group was significantly larger than that in reformative group (P<0.05). ConclusionBoth single and double Cage implanted into the intervertebral body through unilateral TLIF have good effectiveness. However, double Cage implanted into intervertebral body may hold the height of intervertebral space, reduce the incident rate of Cage subsidence, and prevent sagittal imbalance.
ObjectiveTo explore the fusion effect of allograft Cages on transforaminal lumbar interbody fusion (TLIF).MethodsThe clinical data of 30 patients (38 vertebral segments) who underwent TLIF with allograft interbody fusion Cages between January 2015 and January 2017 were retrospectively analysed. There were 25 males and 5 females with an average age of 56.9 years (range, 44-72 years). The lesions included 20 cases of lumbar disc herniation, 7 cases of lumbar spondylolisthesis, and 3 cases of lumbar spinal stenosis. The operation section included 4 cases of L3, 4, 13 cases of L4, 5, 5 cases of L5, S1, 6 cases of L4, 5-L5, S1, and 2 cases of L3, 4-L4, 5. The disease duration was 6-36 months (mean, 12 months). The clinical effectiveness was evaluated by visual analogue scale (VAS) score, Oswestry disability index (ODI), and Japanese Orthopaedic Association (JOA) score at preoperation, 3 months and 6 months after operation, and last follow-up. The fusion rate was evaluated by anteroposterior and lateral X-ray films and CT three-dimensional reconstruction at 3 and 6 months after operation. The intervertebral space height was measured on anteroposterior and lateral X-ray films at preoperation, 3 days, 3 months, and 6 months after operation.ResultsThe operation time was 2.1-4.3 hours (mean, 3.1 hours), and the intraoperative blood loss was 150-820 mL (mean, 407.5 mL). The follow-up time was 8-25 months (mean, 16.4 months). One Cage split at 6 months after operation without Cage movement and neurologic symptoms; none of the other patients had Cage prolapse, displacement, and fragmentation. No local or systemic allergy or infection signs was found in all patients. No nerve compression or symptoms was observed during the follow-up. The postoperative VAS score, ODI score, and JOA score improved significantly when compared with preoperative scores (P<0.05); and the scores at 6 months and at last follow-up were significantly improved when compared with those at 3 months after operation (P<0.05); but no significant difference was found between at 6 months and at last follow-up (P>0.05). The fusion rate was 55.3% (21/38), 92.1% (35/38), and 100% (38/38) at 3 months, 6 months, and last follow-up postoperatively. The intervertebral space height was increased significantly at 3 days, 3 months, 6 months, and last follow-up postoperatively when compared with preoperative ones (P<0.05); and the loss of intervertebral space height was significant at last follow-up when compared with postoperative at 3 days (P<0.05).ConclusionThe allograft interbody fusion Cage contributes to the spine interbody fusion by providing an earlier stability and higher fusion rate.
Objective To explore the clinical application value of the spinal robot-assisted surgical system in mild to moderate lumbar spondylolisthesis and evaluate the accuracy of its implantation. Methods The clinical data of 56 patients with Meyerding grade Ⅰ or Ⅱ lumbar spondylolisthesis who underwent minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) between January 2017 and December 2017 were retrospectively analysed. Among them, 28 cases were preoperatively planned with robotic arm and percutaneous pedicle screw placement according to preoperative planning (group A); the other 28 cases underwent fluoroscopy-guided percutaneous pedicle screw placement (group B). There was no significant difference in gender, age, body mass index, slippage type, Meyerding grade, and surgical segmental distribution between the two groups (P>0.05). The screw insertion angle was measured by CT, the accuracy of screw implantation was evaluated by Neo’s criteria, and the invasion of superior articular process was evaluated by Babu’s method. Results One hundred and twelve screws were implanted in the two groups respectively, 5 screws (4.5%) in group A and 26 screws (23.2%) in group B penetrated the lateral wall of pedicle, and the difference was significant (χ2=9.157, P=0.002); the accuracy of nail implantation was assessed according to Neo’s criteria, the results were 107 screws of degree 0, 3 of degree 1, 2 of degree 2 in group A, and 86 screws of degree 0, 16 of degree 1, 6 of degree 2, 4 of degree 3 in group B, showing significant difference between the two groups (Z=4.915, P=0.031). In group B, 20 (17.9%) screws penetrated the superior articular process, while in group A, 80 screws were removed from the decompression side, and only 3 (3.8%) screws penetrated the superior articular process. According to Babu’s method, the degree of screw penetration into the facet joint was assessed. The results were 77 screws of grade 0, 2 of grade 1, 1 of grade 2 in group A, and 92 screws of grade 0, 13 of grade 1, 4 of grade 2, 3 of grade 3 in group B, showing significant difference between the two groups (Z=7.814, P=0.029). The screw insertion angles of groups A and B were (23.5±6.6)° and (18.1±7.5)° respectively, showing significant difference (t=3.100, P=0.003). Conclusion Compared to fluoroscopy-guided percutaneous pedicle screw placement, robot-assisted percutaneous pedicle screw placement has the advantages such as greater accuracy, lower incidence of screw penetration of the pedicle wall and invasion of the facet joints, and has a better screw insertion angle. Combined with MIS-TLIF, robot-assisted percutaneous pedicle screw placement is an effective minimally invasive treatment for lumbar spondylolisthesis.
ObjectiveTo investigate the effectiveness of modified direction-changeable lumbar Cage in transforaminal lumbar interbody fusion (TLIF).MethodsA retrospective analysis was made of 161 patients with single segment L4 or L5 isthmic spondylolisthesis treated between January 2013 and December 2015. According to the implantation of Cage, they were divided into trial group (85 cases, modified direction-changeable lumbar Cage implanted in TLIF) and control group (76 cases, traditional nondirection-changeable Cage implanted in TLIF). There was no significant difference in the general data of gender, age, disease duration, slippage segment, and slippage grade between the two groups (P>0.05). The intraoperative implantation time of Cage, Cage position adjustments times, fluoroscopy times during implantation of Cage, fluoroscopy exposure time, and total operation time were recorded and compared between the two groups. Visual analogue scale (VAS) and Oswestry disability index (ODI) scores were used to evaluate the effectiveness of the patients before operation, and at 3, 6, and 12 months after operation, and the incidence of complications was recorded and analyzed. CT examinations were performed at 6 and 12 months after operation, and lumbar fusion was evaluated by Bridwell criteria.ResultsThe intraoperative implantation time of Cage, Cage position adjustments times, fluoroscopy times during implantation of Cage, fluoroscopy exposure time, and total operation time in trial group were significant less than those in control group (P<0.05). All the 161 patients were followed up 12-18 months (mean, 14.3 months). There was 1 case of dural sac tear in the trial group and 1 case of superficial infection in the control group; no complication such as dural tear and infection occurred in other patients. The fusion rate was 76.5% (64/85) in the trial group and 57.9% (44/76) in the control group at 6 months after operation, showing significant difference (χ2=6.44, P=0.02); at 12 months after operation, the fusion rate was 96.5% (82/85) in the trial group and 90.8% (69/76) in the control group (including 3 cases of Cage displacement and 4 cases of screw breakage), showing no significant difference in the fusion rate between the two groups (χ2=1.54, P=0.26). The VAS and ODI scores of the two groups decreased gradually at 3, 6, and 12 months after operation, and improved significantly when compared with those before operation (P<0.05). There was no significant difference in VAS and ODI scores between the two groups before and after operation (P>0.05).ConclusionBoth Cages can obtain the similar effectiveness. The modified direction-changeable lumbar Cage can significantly reduce the fluoroscopy times and radiation dose during TLIF, shorten the operation time, and effectively reduce the radiation exposure of patients and medical staff.
ObjectiveTo explore the risk factors of coronal imbalance after posterior long-level fixation and fusion for degenerative lumbar scoliosis.MethodsRetrospectivly analyzed the clinical records of 41 patients with degenerative lumbar scoliosis who had received posterior long-level fixation and fusion with selective transforaminal lumbar interbody fusion (TLIF) accompanied by Ponte osteotomy between August 2011 and July 2016. Patients were divided into imbalance group (group A, 11 cases) and balance group (group B, 30 cases) according to state of coronal imbalance measured at last follow-up. The radiographic parameters at preoperation and last follow-up were measured, and the variance of preoperative and last follow-up parameters were calculated. The radiographic parameters included coronal Cobb angle, coronal balance distance (CBD), apical vertebral translation (AVT), apical vertebral rotation (AVR), Cobb angle of lumbar sacral curve (LSC), and L5 tilt angle (L5TA). Univariate analysis was performed for the factors including gender, age, preoperative T value of bone mineral density, number of instrumented vertebra, upper and lower instrumented vertebra, segments of TLIF, decompression, and Ponte osteotomy, as well as the continuous variables of preoperative imaging parameters with significant difference were converted into two-category variables, obtained the influence factors of postoperative coronal imbalance. Multivariate logistic regression analysis was performed to verify the risk factors from the preliminary screened influence factors and the variance of imaging parameters with significant difference between the two groups.ResultsThe follow-up time of groups A and B was (3.76±1.02) years and (3.56±1.03) years respectively, there was no significant difference between the two groups (t=0.547, P=0.587). The coronal Cobb angle, AVT, LSC Cobb angle, and L5TA in group A were significantly higher than those in group B before operation (P<0.05), and all the imaging parameters in group A were significantly higher than those in group B at last follow-up (P<0.05). There was no significant difference between the two groups in parameters including the variance of coronal Cobb angle, AVT, and LSC Cobb angle before and after operation (P>0.05), and there were significant differences between the two groups in parameters including the variance of CBD, L5TA, and AVR (P<0.05). Univariate analysis showed that preoperative L5TA was the influencing factor of postoperative coronal imbalance (P<0.05). Multivariate logistic regression analysis showed that preoperative L5TA≥15° was an independent risk factor of postoperative coronal imbalance, and variance of pre- and post-operative AVR was a protective factor.ConclusionPreoperative L5TA≥15° is an independent risk factor for coronal imbalance in patients with degenerative lumbar scoliosis after posterior long-level fixation and fusion.
ObjectiveTo investigate the clinical results and complication prevention of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of single-segment severe lumbar spinal stenosis (LSS).MethodsThe clinical data of 112 patients with severe LSS treated with MIS-TLIF between January 2010 and January 2017 were retrospectively analyzed. There were 43 males and 69 females, aged 52-81 years, with an average age of 65.3 years. The disease duration ranged from 4 to 126 months, with an average of 10.5 months. Clinical manifestations: 104 cases of low back pain, 91 cases of nervous intermittent claudication of both lower limbs, 21 cases of unilateral nerve root pain and/or numbness, and 5 cases of cauda equina nerve injury. The 112 cases were all severe central spinal stenosis, including 32 cases with lateral recess stenosis, 20 cases with foramen stenosis, 9 cases with ossification of ligamentum flavum, 38 cases with disc herniation; 14 cases with two complications and 5 cases with three. Stenosis segment: L3, 4 in 6 cases, L4, 5 in 89 cases, and L5, S1 in 17 cases. Surgical methods included bilateral decompression through bilateral approach (60 cases), bilateral decompression through unilateral approach (15 cases), and unilateral decompression (37 cases). The operation time, intraoperative blood loss, visual analogue scale (VAS) score of low back pain and leg pain, Oswestry disability index (ODI) score, fusion rate, and surgical complications were recorded. At last follow-up, the lumbar fusion was evaluated by Bridwell method, grades Ⅰ and Ⅱ were expressed as fusion.ResultsThe operation time was 83-186 minutes (mean, 126.8 minutes), and the intraoperative blood loss was 65-630 mL (mean, 163.1 mL). All the 112 patients were followed up 25-49 months, with an average of 35.1 months. The VAS score of low back pain and leg pain and ODI score at each time point after operation were significantly improved when compared with preoperative scores (P<0.05). There was no significant difference between the VAS score of low back pain and leg pain and ODI score at the other time points except 1 month after operation (P<0.05). At last follow-up, 2 cases of cauda equina nerve injury recovered and 3 cases partially recovered. According to Bridwell classification criteria, 58 cases were grade Ⅰ, 47 cases were grade Ⅱ, and 7 cases were grade Ⅲ. The fusion rate was 93.8%. Perioperative complications included 5 cases of incision complications (superficial infection in 3 cases, hematoma formation in 2 cases), 19 cases of internal fixator complications (intraoperative end plate fracture in 8 cases, fusion cage sinking in 11 cases at last follow-up), and 15 cases of neurological complications (dural sac tear in 10 cases, transient neurological symptoms of lower extremities aggravated in 5 cases). Conclusion MIS-TLIF treatment of single-level severe LSS can achieve good clinical results, while there is a risk of serious complications. Full understanding of the clinical and imaging features of the disease and reasonable and careful operation are helpful to control the occurrence of cauda equina nerve damage.
Objective To analyze the medium and long-term effectiveness of microendoscope-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for lumbar degenerative diseases in comparison with conventional tubular retractor-assisted MIS-TLIF. Methods Between November 2008 and March 2013, 53 patients with single segment lumbar degenerative diseases were enrolled. According to the different working channel performed, 28 patients were treated by microendoscope-assisted MIS-TLIF (observation group), while the remaining cases received conventional tubular retractor-assisted MIS-TLIF via Wiltse approach (control group). Preoperative baseline data, including age, gender, body mass index, disease etiology, operated level, the ration for requiring bilateral canal decompression, and preoperative visual analogue scale (VAS) socre of low back pain and leg pain, Japanese Orthopedic Association (JOA) score, Oswestry disability index (ODI) score, showed no significant difference between the two groups (P>0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy time, postoperative analgesic drug dose, postoperation in-bed time, and perioperative complication incidence were recorded respectively and compared between the two groups. Radiographic evaluation of interbody fusion was performed based on Bridwell grading system at 2 years after operation. VAS scores of low back pain and leg pain, JOA score, and ODI score were assessed before operation, at 2 years after operation, and at last follow-up respectively. Surgical outcome satisfaction was assessed by modified MacNab criteria at last follow-up. Results When compared with those in control group, both intraoperative blood loss and postoperative analgesic drug dose were significantly decreased in observation group (P<0.05); similarly, the operation time and intraoperative fluoroscopy time were also significantly increased in observation group (P<0.05). There was no significant difference of postoperative in-bed time between the two groups (t=–0.812, P=0.420). Both groups were followed up 6-10.3 years, with an average of 7.9 years. Regarding perioperative complication, its incidence was 14.3% and 20.0% in observation group and control group, respectively, showing no significant difference between both groups (χ2=0.306, P=0.580). Specifically, there were intraspinal hematoma formation in 1 case, incision infection in 1 case, urinary infection in 1 case, transient delirium in 1 case in observation group. By contrast, there were dural tear and cerebrospinal fluid leakage in 1 case, urinary infection in 1 case, pneumonia in 1 case, transient delirium in 2 cases in control group. Bridwell criterion was used to judge the intervertebral fusion at 2 years after operation, the fusion rates of observation group and control group were 92.9% and 92.0%, respectively, showing no significant difference (χ2=0.162, P=0.687). At both 2-year postoperatively and last follow-up, the VAS scores of low back pain and leg pain, JOA score, and ODI score were significantly improved when compared with those before operation (P<0.01), whereas no significant difference between the two groups at either time point was found (P>0.05). At last follow-up, the results of patients’ satisfaction with surgery evaluated by modified MacNab criteria, and the excellent and good rates of the observation group and the control group were 96.4% and 92.0%, respectively, showing no significant difference (χ2=0.485, P=0.486). Conclusion The medium and long-term effectiveness of microendoscope-assisted MIS-TLIF are similar to those of conventional tubular retractor-assisted MIS-TLIF for lumbar degenerative diseases. The former operation has the additional advantages in terms of more clear surgical site visually, less intraoperative blood loss, and reduced postoperative analgesic dose, all of which seem more feasible to clinical teaching.