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 compare the biomechanical differences between the kidney-shaped nano-hydroxyapatite/polyamide 66 (n-HA/PA66) Cage and the bullet-shaped n-HA/PA66 Cage. MethodsL2-L5 spinal specimens were selected from 10 adult male pigs. L2, L3 and L4, L5 served as a motor unit respectively, 20 motor units altogether. They were divided into 4 groups (n=5):no treatment was given as control group (group A); nucleus pulposus resection was performed (group B); bullet-shaped Cage (group C), and kidney-shaped Cage (group D) were used in transforaminal lumbar interbody fusion (TLIF) through left intervertebral foramen and supplemented by posterior pedicle screw fixation. The intervertebral height (IH) and the position of Cages were observed on the X-ray films. The range of motion (ROM) was measured. ResultsThere was no significant difference in the preoperative IH among 4 groups (F=0.166, P=0.917). No significant change was found in IH between at pre- and post-operation in group B (P>0.05); it increased after operation in groups C and D, but difference was not statistically significant (P>0.05). There was no significant difference in the postoperative IH among groups B, C, and D (P>0.05). The distance from Cage to the left margin was (3.06±0.51) mm in group C (close to the left) and (5.68±0.69) mm in group D (close to the middle), showing significant difference (t=6.787, P=0.000). The ROM in all directions were significantly lower in groups C and D than in groups A and B (P<0.05), and in group A than in group B (P<0.05). The right bending and compression ROM of group C were significantly higher than those of group D (P<0.05), but no statistically significant difference was found in the other direction ROM (P>0.05). ConclusionThe bullet-shaped and kidney-shaped Cages have similar results in restoring IH and maintaining the stability of the spine assisted by internal fixation. Kidney-shaped Cage is more stable than bullet-shaped Cage in the axial compression and the bending load opposite implant, it can be placed in the middle and back of the vertebral body more ideally.
ObjectiveTo explore the effectiveness of posterior lumbar interbody fusion in the treatment of double-segmental bilateral isthmic lumbar spondylolisthesis. MethodsBetween February 2008 and December 2013, 17 patients with double-segmental bilateral isthmic lumbar spondylolisthesis were treated with posterior lumbar interbody fusion. There were 12 males and 5 females, with an age ranged 48-69 years (mean, 55.4 years). The disease duration ranged from 11 months to 17 years (median, 22 months). According to the Meyerding classification, 30 vertebrea were rated as degree I, 3 as degree Ⅱ, and 1 as degree Ⅲ. L4, 5 was involved in 14 cases and L3, 4 in 3 cases. The preoperative visual analogue scale (VAS) score was 8.6±3.2. ResultsCerebrospinal fluid leakage occurred in 2 cases because of intraoperative dural tear; primary healing of incision was obtained, with no operation related complication in the other patients. The patients were followed up 1-6 years (mean, 3.4 years). At last follow-up, VAS score was decreased significantly to 1.1±0.4, showing significant difference when compared with preoperative score (t=7.652, P=0.008). X-ray films showed that slippage vertebral body obtained different degree of reduction, with a complete reduction rate of 85% (29/34) at 1 week after operation. All patients achieved bony union at 6-12 months (mean, 7.4 months). According to the Lenke classification, 13 cases were rated as grade A and 4 cases as grade B. No internal fixation loosening and fracture were observed during the follow-up. Intervertebral disc height was maintained, no loss of spondylolisthesis reduction was found. ConclusionIt can obtain satisfactory clinical result to use spinal canal decompression by posterior approach, and screw fixation for posterior fusion in treatment of double-segmental bilateral isthmic lumbar spondylolisthesis. The key points to successful operation include accurate insertion of screw, effective decompression, distraction before reduction, rational use of pulling screws, and interbody fusion.
Objective To compare the clinical and radiological outcomes of unilateral biportal endoscopic transforaminal lumbar interbody fusion (UBE-TLIF) and minimally invasive tubular TLIF (MT-TLIF) in treatment of lumbar degenerative diseases. Methods A clinical data of 75 patients with lumbar degenerative diseases, who met the selection criteria between August 2019 and August 2020, was retrospectively analyzed, including 35 patients in the UBE- TLIF group and 40 patients in the MT-TLIF group. There was no significant difference in general data such as gender, age, body mass index, disease type and duration, and surgical segment between the two groups (P>0.05), which was comparable. The operation time, intraoperative blood loss, hemoglobin (Hb) before operation and at 1 day after operation, the length of hospital stay, incidence of complications, and visual analogue scale (VAS) score of low back and leg pain, Oswestry Disability Index (ODI), Short-Form 36 Health Survey Scale (SF-36 scale), intervertebral disc height (IDH), sagittal Cobb angle, lumbar lordosis (LL), and the intervertebral fusion were compared between the two groups. Results Compared with MT-TLIF group, UBE-TLIF group had significantly longer operation time but less intraoperative blood loss and shorter length of hospital stay (P<0.05). The Hb levels in both groups decreased at 1 day after operation, but there was no significant difference in the difference before and after operation between the two groups (P>0.05). All patients were followed up, and the follow-up time was (14.7±2.5) months in the UBE-TLIF group and (15.0±3.4) months in the MT-TLIF group, with no significant difference (t=0.406, P=0.686). In both groups, the VAS score of low back pain, VAS score of leg pain, SF-36 scale, and ODI after operation significantly improved when compared with those before operation (P<0.05). There was no significant difference between 1 month after operation and last follow-up (P>0.05). There was no significant difference in the VAS score of low back pain, VAS score of leg pain, and SF-36 scale between the two groups before and after operation (P>0.05). At 1 month after operation, the ODI in the UBE-TLIF group was significantly better than that in the MT-TLIF group (P<0.05). At 1 month after operation, IDH, Cobb angle, and LL in both groups recovered when compared with those before operation (P<0.05), and were maintained until last follow-up (P>0.05). There was no significant difference in the IDH, Cobb angle, and LL between the two groups at each time point (P>0.05). Thirty-three cases (89.2%) in the UBE-TLIF group and 35 cases (87.5%) in the MT-TLIF group achieved fusion, and the difference was not significant (χ2=0.015, P=0.901). In the UBE-TLIF group, 1 case of intraoperative dural tear and 1 case of postoperative epidural hematoma occurred, with an incidence of 5.7%. In the MT-TLIF group, 1 case of intraoperative dural tear, 1 case of postoperative epidural hematoma, and 1 case of superficial infection of the surgical incision occurred, with an incidence of 7.5%. There was no significant difference in the incidence of complications between the two groups (χ2=1.234, P=1.000). Conclusion Compared with MT-TLIF, UBE-TILF can achieve similar interbody fusion in the treatment of lumbar degenerative diseases, and has the advantages of smaller incision, less bleeding, and shorter length of hospital stay.
ObjectiveTo compare the effectiveness of robot-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and open freehand TLIF for the treatment of single-level degenerative lumbar spondylolisthesis (DSL) and analyse the influence on postoperative adjacent segmental degeneration (ASD). Methods The clinical data of 116 patients with L4、5 DLS who were admitted between November 2019 and October 2021 and met the selection criteria were retrospectively analyzed. According to the surgical methods, they were divided into the robotic group (45 cases, who underwent robot-assisted MIS-TLIF) and the open group (71 cases, who underwent open freehand TLIF). There was no significant difference in baseline data such as gender, age, body mass index, DLS Meyerding grading, and preoperative Pfirrmann grading, Weishaupt grading, L3, 4 intervertebral disc height (DH), L3, 4 intervertebral mobility, sagittal parameters [including pelvic incidence (PI), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT)], and Cage height (P>0.05). The grade of facet joint violation (FJV) by pedicle screws on the superior articular process was assessed postoperatively. Sagittal parameters, L3, 4 DH, L3, 4 DH loss, and L3, 4 intervertebral mobility were measured preoperatively and at last follow-up in order to determine whether ASD occurred. Based on the occurrence of postoperative ASD, logistic regression analysis was used to identify the risk factors for ASD after TLIF. Results Patients in both groups were followed up 21-47 months, with a mean of 36.1 months; there was no significant difference in the follow-up time between the two groups (P>0.05). The occurrence of postoperative FJV was significantly better in the robotic group than in the open group (P<0.05). At last follow-up, the difference in the change values of sagittal parameters PI, PT, SS, and LL was not significant when comparing the two groups of patients (P>0.05); the change values of L3, 4 DH and L3, 4 DH loss in the robotic group were smaller than those in the open group, and the change value of L3, 4 intervertebral mobility was larger than that in the open group, and the differences were significant (P<0.05). At last follow-up, ASD occurred in 8 patients (17.8%) in the robotic group and 35 patients (49.3%) in the open group, and the difference in ASD incidence between the two groups was significant (P<0.05). logistic regression analysis showed that open surgery, preoperative Pfirrmann grading Ⅳ-Ⅴ, preoperative Weishaupt grading ≥2, and postoperative FJV grading ≥1 were risk factors for the development of ASD after TLIF (P<0.05). ConclusionCompared with traditional open surgery, orthopedic robot-assisted MIS-TLIF in the treatment of single-level DLS can more accurately insert pedicle screws, reduce the loss of DH and the occurrence of FJV, and effectively reduce the incidence of mid-postoperative ASD. Preoperative disc and synovial joint degeneration in adjacent segments, nonrobotic-assisted minimally invasive therapy, and FJV are risk factors for ASD after TLIF.
ObjectiveTo study the anatomical characteristics of blood vessels in the lateral segment of the vertebral body through the surgical approach of oblique lumbar interbody fusion (OLIF) using MRI imaging, and evaluate its potential vascular safety zone. Methods The lumbar MRI data of 107 patients with low back and leg pain who met the selection criteria between October 2019 and November 2022 were retrospectively analyzed. The vascular emanation angles, vascular travel angles, and the length of vessels in the lateral segments of the left vertebral body of L1-L5, as well as the distance between the segmental vessels in different Moro junctions of the vertebral body and their distances from the edges of the vertebrae in the same sequence (bottom marked as I, top as S) were measured. The gap between the large abdominal vessels and the lateral vessels of the vertebral body was set as the lateral vascular safe zones of the lumbar spine, and the extent of the safe zones (namely the area between the vessels) was measured. The anterior 1/3 of the lumbar intervertebral disc was taken as the simulated puncture center, and the area with a diameter of 22 mm around it as the simulated channel area. The proportion of vessels in the channel was further counted. In addition, the proportions of segmental vessels at L5 without a clear travel and with an emanation angel less than 90° were calculated. Results Except for the differences in the vascular emanation angles between L4 and L5, the vascular travel angles between L1, L2 and L4, L5, and the length of vessels in the lateral segments of the vertebral body among L1-L4 were not significant (P>0.05), the differences in the vascular emanation angles, vascular travel angles, and the length of vessels between the rest segments were all significant (P<0.05). There was no significant difference in the distance between vessels of L1, L2 and L2, L3 at Moro Ⅰ-Ⅳ junctions (P>0.05), in L3, L4 and L4, L5 at Ⅱ and Ⅲ junction (P>0.05). There was no significant difference in the vascular distance of L2, L3 between Ⅱ, Ⅲ junction and Ⅲ, Ⅳ junction, and the vascular distance of L3, L4 between Ⅰ, Ⅱ junction and Ⅲ, Ⅳ junction (P>0.05). The vascular distance of the other adjacent vertebral bodies was significant different between different Moro junctions (P<0.05). Except that there was no significant difference in the distance between L2I and L3S at Ⅰ, Ⅱ junction, L3I and L4S at Ⅱ, Ⅲ junction, and L2I and L3S at Ⅲ, Ⅳ junction (P>0.05), there was significant difference of the vascular distance between the bottom of one segment and the top of the next in the other segments (P<0.05). Comparison between junctions: Except for the L3S between Ⅰ, Ⅱ junction and Ⅱ, Ⅲ junction, and L5S between Ⅰ, Ⅱ junction and Ⅱ, Ⅲ and Ⅲ, Ⅳ junctions had no significant difference (P>0.05), there were significant differences in the distance between the other segmental vessels and the vertebral edge of the same sequence in different Moro junctions (P<0.05). The overall proportion of vessels in the simulated channels was 40.19% (43/107), and the proportion of vessels in L1 (41.12%, 44/107) and L5 (18.69%, 20/107) was higher than that in the other segments. The proportion of vessels in the channel of Moro zone Ⅰ (46.73%, 50/107) and zone Ⅱ (32.71%, 35/107) was higher than that in the zone Ⅲ, while no segmental vessels in L1 and L2 were found in the channel of zone Ⅲ (χ2=74.950, P<0.001). Moreover, 26.17% (28/107) of the segmental vessels of lateral L5 showed no movement, and 27.10% (29/107) vascular emanation angles of lateral L5 were less than 90°. Conclusion L1 and L5 segmental vessels are most likely to be injured in Moro zones Ⅰ and Ⅱ, and the placement of OLIF channels in L4, 5 at Ⅲ, Ⅳ junction should be avoided. It is usually safe to place fixation pins at the vertebral body edge on the cephalic side of the intervertebral space, but it is safer to place them on the caudal side in L1, 2 (Ⅰ, Ⅱ junction), L3, 4 (Ⅲ, Ⅳ junction), and L4, 5 (Ⅱ, Ⅲ, Ⅳ junctions).
ObjectiveTo investigate the correlation between the effectiveness and the changes of spine-pelvic sagittal parameters for patients with spondylolisthesis before and after operation. MethodsA retrospective analysis was made on the clinical data of 32 patients with single segmental degenerative lumbar spondylolisthesis at L4 who accorded with the inclusion criteria between June 2011 and January 2014 (trial group). There were 13 males and 19 females, aged 51-67 years (mean, 59 years). According to Meyerding degree, there were 21 cases of degree I, 10 cases of degree Ⅱ, and 1 case of degree Ⅲ. All patients were treated with transforaminal lumbar interbody fusion (TLIF) surgery. Thirty-five healthy adults at the age of 46-67 years (mean, 57 years) were enrolled as normal controls (control group). The standing position lumbar lateral X-ray films (T12-S1, bilateral femoral head) were taken at pre- and post-operation to measure the pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), disc height (DH), and slip percentage (SP); the visual analogue scale (VAS) and Oswestry disability index (ODI) were recorded. Pearson correlation analysis was used to analyze the correlation between the preoperative various spine-pelvic sagittal parameters and the VAS score and the ODI. After operation, Pearson correlation analysis was used to evaluate the correlation between the changes of these parameters and the improve rates of VAS score and ODI. ResultsAll patients of trial group were followed up 15-22 months (mean, 18 months). At last follow-up, the VAS score, ODI, PT, SS, LL, SP, and DH were significantly improved when compared with preoperative values (P<0.05), except for PI (t=-1.445, P=0.158). There was no significant difference in PT, SS, LL, and DH between trial and control groups at last follow-up (P>0.05); PI was slightly bigger than that of control group (t=8.531, P=0.043). Pearson correlation analysis showed that there was a correlation between spine-pelvic sagittal parameters of PI, PT, SS, and LL (P<0.05); preoperative parameters (except for LL and DH) had correlation with ODI and VAS scores (P<0.05). Postoperative parameters (except for PI) had correlation with the improve rates of ODI and VAS scores (P<0.05), especially for the changes of PT and the improvements of ODI and VAS scores. ConclusionThere is a correlation between the changes of spine-pelvic sagittal parameters at pre- and post-operation and effectiveness in patients with lumbar spondylolisthesis. The correlation between the changes of PT and the improvement rates of ODI and VAS scores is more marked. The good effectiveness is closely related with the improved PT.
Objective To summarize the basic research and the cl inical appl ication of biodegradable interbody fusion Cage. Methods Recent l iterature concerning biodegradable interbody fusion Cage at home and abroad was extensively reviewed, and current developments of the basic research and the cl inical appl ication of biodegradable interbody fusion Cage were investigated. Results Basic research showes that the stiffness of biodegradable interbody fusion Cage is lower than that of metall ic Cage, so it can enhance interbody fusion. As interbody fusion proceeded, biodegradable interbody fusion Cage degrades constantly, but the speed of degradation can not keep in parallel with that of fusion. In addition, the tissue response to degradation products is controversy. Cl inical appl ication showes that the biodegradable interbody fusion Cage can enhance interbody fusion and maintain disc space height. The short term results are good, however, the long term results need further observation. Conclusion Biodegradable interbody fusion Cage can effectively enhance interbody fusion.
ObjectiveTo evaluate the effectiveness of transforaminal lumbar interbody fusion (TLIF) via Luxor retractor associated with Mantis pedicle screw for the treatment of moderate or severe lumbar spondylol isthesis (LSL). MethodsA retrospective analysis was made on the cl inical data of 32 patients with LSL treated with TLIF via Luxor retractor associated with Mantis pedicle screw between June 2010 and June 2012. There were 20 males and 12 females, with the mean age of 48 years (range, 36-69 years). LSL occurred at the L4, 5 in 17 patients and at the L5, S1 in 15 patients. Of them, 18 cases were rated as Meyerding grade Ⅱ, and 14 cases as grade Ⅲ. The disease duration was 8 months to 6 years (mean, 3.5 years). The operation time, intraoperative blood loss, and preoperative and postoperative (1 week and 1 year) intervertebral height and sl ipping angle were recorded, and the sl ipping rate was calculated; Japanese Orthopaedic Association (JOA) score was used for cl inical efficacy assessment. ResultsThe operation time was 90-130 minutes (mean, 110 minutes); intraoperative blood loss was 120-300 mL (mean, 210 mL). Incisions healed by first intention. All patients were followed up 24-36 months (mean, 28 months), and no complications of leakage of cerebrospinal fluid and nerve root injury occurred; X-ray films showed satisfactory reduction of spondylolisthesis and good position of pedicle screw and interbody fusion cage. The mean bone fusion time was 4.0 months (range, 3.8-6.0 months). The JOA score, sl i pping rate, sl i pping angle, and intervertebral height at 1 week and 1 year after operation were significantly improved when compared with preoperative ones (P<0.05), but no significant difference was found between at 1 week and at 1 year after operation (P>0.05). ConclusionTLIF via Luxor retractor associated with Mantis pedicle screw fixation is a safe and effective minimally invasive technique in treating moderate or severe LSL.
ObjectiveTo investigate the early effctiveness of oblique lateral interbody fusion (OLIF) combined with pedicle screw fixation via small incision Wiltse approach for the treatment of lumbar spondylolisthesis.MethodsBetween January 2016 and December 2016, 21 patients with lumbar spondylolisthesis were treated with OLIF and pedicle screw fixation via small incision Wiltse approach. There were 9 males and 12 females, aged 57-73 years, with an average age of 64.5 years. The disease duration was 24-60 months, with an average of 34.6 months. All cases were spondylolisthesis at L4 (15 cases of degreeⅠ, 6 cases of degreeⅡ); 1 case had vertebral arch isthmus, and 20 cases had spinal stenosis. Japanese Orthopaedic Association (JOA) scoring system was used to evaluate the effectiveness before operation and at last follow-up. Before operation and at 2 days after operation, anteroposterior and lateral X-ray films and CT were taken to measure the sagittal diameter and cross-sectional area of the spinal canal, and calculate the intervertebral height and degree of spondylolisthesis. At 6 months after operation, the intervertebral fusion was evaluated by CT.ResultsThe operation time was 120-180 minutes, with an average of 155 minutes; the intraoperative blood loss was 100-340 mL, with an average of 225.5 mL. One patient had slight injury of lower endplate, 1 patient had numbness of thigh and weakness of hip flexion after operation, 1 patient had sympathetic nerve trunk injury. All the cases were followed up 12-18 months, with an average of 14.3 months. The symptoms of low back pain, leg pain, and numbness of lower limbs significantly relieved after operation, and there was no complication such as protrusion of fusion cage, screw breakage, and endplate collapse. At 2 days after operation, the intervertebral height, degree of spondylolisthesis, sagittal diameter of spinal canal, and cross-sectional area of spinal canal significantly improved compared with preoperative ones (P<0.05). At 6 months after operation, CT showed that 1 patient had poor interbody fusion (grade Ⅲ), the other 20 patients had good interbody fusion (grade Ⅰ and Ⅱ), and the interbody fusion rate was 95.2%. At last follow-up, JOA score of lumbar spine significantly increased compared with that before operation (t=24.980, P=0.000).ConclusionOLIF combined with pedicle screw fixation via small incision Wiltse approach for the lumbar spondylolisthesis has minimally invasive features, such as less trauma, fewer complications, and higher intervertebral fusion rate. It is a safe and effective method.