[Contralateral endoscopic approach for lumbar foraminal stenosis using unilateral biportal endoscopic surgery].

OBJECTIVE: To assess the feasibility and imaging outcomes of unilateral biportal endoscopic technique in the treatment of lumbar foraminal stenosis through contralateral approach. METHODS: The clinical data of 33 patients with lumbar foraminal stenosis treated with unilateral biportal endoscopic technique from January 2021 to July 2022 were retrospectively analyzed. There were 17 males and 16 females;age ranging from 34 to 72 years old with an average of (56.00±7.89) years old;operation time and perioperative complications were recorded;visual analogue scale (VAS) of pain was recorded, to evaluate the degree of low back pain and lower extremity pain, and Oswestry disability index (ODI) to evaluate the lumbar spine function. At the latest follow-up, the modified Macnab score was used to evaluate the clinical efficacy. RESULTS: All patients successfully completed the operation. The operation time ranged from 47 to 65 minutes, with an average of (56.10±5.19) minutes. The postoperative follow-up ranged from 12 to 18 months, with an average of (14.9±2.3) months. The VAS of low back and lower extermity pain before operation were (7.273±1.442) and (7.697±1.447) scores, ODI was (69.182±9.740)%. Postoperative lumbocrural pain VAS were (3.394±0.966) and (2.818±0.727) scores, ODI was (17.30±4.78) %. At the latest follow-up, VAS of back and lower extermity pain was (2.788±0.650) and (2.394±0.704) scores, ODI was (14.33±350)%. There were significant differences in VAS of low back and lower extremity pain and ODI before and after operation(P<0.05). At the latest follow-up, according to the modified Macnab criteria, 24 patients got excellent result, 5 as good, 2 as fair, and 2 as poor. CONCLUSION: Unilateral biportal endoscopic treatment of lumbar foraminal stenosis through the contralateral approach is a safe and efficient method, with few complications, quick postoperative recovery, and satisfactory clinical outcomes. During the follow-up period, no iatrogenic lumbar instability was observed.

[Experimental study of proteasome inhibitor MG132 up-regulates Wnt/ß-catenin signaling pathway to improve osteoporosis].

OBJECTIVE: To explore the mechanism of proteasome inhibitor MG132 in improving osteoporosis. METHODS: Total of 32 female SD rats, weighing 220 to 250 g and 8 weeks old, were selected. They were randomly divided into 4 groups(n=8). Rats of group A and group B were cut off ovaris on both sides to make model of osteoporosis, and then they were given proteasome inhibitors MG132 and dimethyl sufoxide (DMSO) respectively. Group C was a sham group and rats were given MG132. Group D was a normal group and rats were given MG132 too. The rats were killed in batches at 6 and 12 weeks after administration, and the femoral neck tissues were obtained. Relevant data were analyzed, such as pathomorphological observation, micro-CT analysis, detection of 20S proteasome activity in tissues, and expression of Wnt and ß-catenin. RESULTS: Morphological observation showed that the trabecular were slightly thinner, reticulated, and occasionally interrupted in group A, while the trabecular were obviously thinner and discontinuous in group B. And the trabecular were intact and arranged reticulated in group C and D. The analysis results of bone mineral density(BMD), bone surface(BS), bone volume/total volume(BV/TV) and trabecular thickness(Tb.Th) showed that group B was worse than other groups in all parameters at different time points(P<0.05), and group A was worse than group C and group D in BS(P<0.05), there was no significant difference in all parameters between group C and group D. RFU value of 20S proteasome in group B was significantly higher than that in other groups(P<0.05). According to the results of Western blot, the gray values of Wnt protein and ß-catenin protein in group A were significantly higher than those in other groups (P<0.05). CONCLUSION: MG-132, a ubiquitin proteasome inhibitor, can regulate Wnt/ß-catenin signaling pathway by inhibiting the degradation of ß-catenin protein, and delaying the occurrence and development of osteoporosis.

[Treatment of thoracolumbar burst fractures with intelligent inflated reduction combined with percutaneous pedicle screw fixation].

OBJECTIVE: To evaluate the clinical outcome of intelligent inflated reduction combined with percutaneous pedicle screw fixation in treating thoracolumbar burst fractures. METHODS: The clinical data of 22 patients with thoracolumbar burst fractures of single segment treated from January 2013 to December 2015 were retrospectively analyzed. There were 12 males and 10 females, aged from 32 to 56 years old with an average of (42.4±8.6) years. Self-made intelligent pneumatic reset instrument was applied to 22 cases under anaesthesia reduction, and then percutaneous pedicle screw fixation was performed. Clinical features were observed and the clinical effects were evaluated by VAS, ODI, kyphotic angle (Cobb angle) and the injured vertebral anterior border height before and after operation. RESULTS: All the patients were followed up from 1 to 2.5 years with an average of 18 months. All fractures obtained bone healing, no complications such as loosening, displacement, breakage of pedicle screw and kyphosis were found. Preoperative, 1 week postoperative, and final follow-up, VAS scores of lumbar pain were 7.82±0.85, 3.09±0.92, 1.05±0.72;ODI scores were 84.2±11.2, 46.3±9.0, 12.2±4.3;Cobb angle were (16.3±5.4)°, (3.7±2.2)°, ( 5.5±2.6)°; the injured vertebral anterior border heights were (59.5±7.8)%, (86.9±6.0)%, (83.5±5.5)%, respectively. There was significant differences in VAS, ODI scores between any two times(P<0.05). At 1 week postoperative and final follow-up, Cobb angle, injuried vertebral anterior border height were obviously improved (P<0.05), and there was no significant difference between postoperative 1 week and final follow-up (P>0.05). CONCLUSIONS: It is safe and feasible surgical technique that intelligent inflated reduction combined with percutaneous pedicle screw fixation for thoracolumbar burst fractures. It has advantage of little trauma, reliable fixation, and less complication, etc. Therefore, it is a better choice for single-segment thoracolumbar burst fractures.

Morphology of the lumbar multifidus muscle in lumbar disc herniation at different durations and at different ages.

The aim of the present study was to evaluate the relative functional volume of bilateral lumbar multifidus (LM) muscles across different stages and ages of patients with lumbar disc herniation (LDH). The relative functional volumes of LM muscles in both non-affected and affected sides in the L4-L5 and L5-S1 segmental level were measured in a resting prone position, and visual analogue score (VAS) for pain and Japanese Orthopedic Association (JOA) scores were recorded. The correlation between changes in the relative net volume of LM muscles and times of onset, ages, VAS and JOA scores were analyzed. A total of 327 cases were selected. The affected sides of LM muscles could present a certain degree of atrophy in stages >3 weeks. During the duration of the course, all cases presented different degrees of LM muscle atrophy. In addition, the degree of LM muscle atrophy was positively correlated with its duration. Age could influence the degree of LM muscle atrophy. Patients with unilateral LDH had <10% asymmetry on relative functional volume in the youth group. At the L4-L5 segments, patients with unilateral LDH had >10% asymmetry within the course of 3 months in the elderly group. The reduced rate of the relative functional net LM muscle volume was positively correlated with VAS scores, age, duration and JOA scores. In conclusion, the reduced rate of relative functional net LM muscle volume was positively correlated with age, duration, VAS scores and JOA scores. Although these findings are unreliable markers of lumbar pathology in an individual level for use in clinical or research settings, there is a notable importance of early intervention in LM muscle atrophy.

Effects of a bone graft substitute consisting of porous gradient HA/ZrO2 and gelatin/chitosan slow-release hydrogel containing BMP-2 and BMSCs on lumbar vertebral defect repair in rhesus monkey.

Dense biomaterial plays an important role in bone replacement. However, it fails to induce bone cell migration into graft material. In the present study, a novel bone graft substitute (BGS) consisting of porous gradient hydroxyapatite/zirconia composite (PGHC) and gelatin/chitosan slow-release hydrogel containing bone morphogenetic protein 2 and bone mesenchymal stem cells was designed and prepared to repair lumbar vertebral defects. The morphological characteristics of the BGS evaluated by a scanning electron microscope showed that it had a three-dimensional network structure with uniformly distributed chitosan microspheres on the surfaces of the graft material and the interior of the pores. Then, BGS (Group A), PGHC (Group B), or autologous bone (Group C) was implanted into lumbar vertebral body defects in a total of 24 healthy rhesus monkeys. After 8 and 16 weeks, anteroposterior and lateral radiographs of the lumbar spine, microcomputed tomography, histomorphometry, biomechanical testing, and biochemical testing for bone matrix markers, including Type I collagen, osteocalcin, osteopontin, basic fibroblast growth factor, alkaline phosphatase, and vascular endothelial growth factor, were performed to examine the reparative efficacy of the BGS and PGHC. The BGS displayed excellent ability to repair the lumbar vertebral defect in rhesus monkeys. Radiography, microcomputed tomography scanning, and histomorphological characterization showed that the newly formed bone volume in the interior of the pores in the BGS was significantly higher than in the PGHC. The results of biomechanical testing indicated that the vertebral body compression strength of the PGHC implant was lower than the other implants. Reverse-transcription polymerase chain reaction and western blot analyses showed that the expression of bone-related proteins in the BGS implant was significantly higher than in the PGHC implant. The BGS displayed reparative effects similar to autologous bone. Therefore, BGS use in vertebral bone defect repair appears promising.

Transforaminal Lumbar Interbody Fusion with Unilateral Pedicle Screw and Contralateral Percutaneous Transfacet Screw Fixation for the Treatment of Lumbar Degenerative Disorders.

AIM: To assess the feasibility and efficacy of TLIF with unilateral pedicle screw and contralateral percutaneous lumbar transfacet screw fixation for the treatment of lumbar degenerative disorders. MATERIAL AND METHODS: A series of computed tomography (CT) digital images from 60 patients (30 males and 30 females) with L3-S1 segments, were reconstructed in three dimensions using a software named Xelis 3D. Linear and angular measurements of the facets were recorded. Fifty-six patients were divided to either bilateral pedicle screw fixation (BPS) (n=30) or unilateral pedicle screw and contralateral percutaneous transfacet screw fixation (UPFS) (n=26) groups. The operating time, blood loss, length of hospital stay, clinical outcomes, fusion and complication rates were compared between the two groups. RESULTS: The parameters of the facets we recorded were no significant differences between the left and right sides (p > 0.05). No statistically significant differences between males and females were observed, except the maximum width of superior facet at L4 and S1, and length of screw at all levels. Intraoperative parameters, such as operating time, blood loss and postoperative hospital stay had significantly larger in the BPS group than UPFS group (p < 0.05). No significant differences were found between the two groups in clinical results, fusion and complication rates (p > 0.05). CONCLUSION: Because of the similar clinical outcomes but less operative time, blood loss and length of postoperatively hospital stay, unilateral pedicle screw and contralateral percutaneous lumbar transfacet screw fixation might be an attractive technique compared to bilateral pedicle screw fixation for treating lumbar degenerative disorders with TLIF. Nevertheless differences of the anatomical parameters for the lumbosacral facets fixation between Chinese and Westerners should be noted.

Evaluation of porous gradient hydroxyapatite/zirconia composites for repair of lumbar vertebra defect in dogs.

OBJECTIVE: To evaluate the effects of porous gradient composites with hydroxyapatite/zirconia and autologous iliac in repair of lumbar vertebra body defects in dogs. METHODS: (1) New porous gradient hydroxyapatite/zirconia composites were prepared using foam immersion, gradient compound and high temperature sintering; (2) A total of 18 adult beagle dogs, aged five to eight months and weighted 10-13 kg, were randomly assigned into two subgroups, which were implanted with new porous gradient hydroxyapatite/zirconia composites (subgroup A in 12) or autologous iliac bone (subgroup B in 6); (3) The post-operative data were analyzed and compared between the subgroups to repair the vertebral body defect by roentgenoscopy, morphology and biomechanics. RESULTS: The porosity of new porous gradient hydroxyapatite/zirconia composites is at 25 poles per inch, and the size of pores is at between 150 and 300 µm. The post-operative roentgenoscopy displayed that new-bone formation is increased gradually, and the interface between composites and host-bone becomes became blur, and the new-bone around the composites were integrated into host-bone at 24 weeks postoperatively in subgroup A. As to subgroup B, the resorption and restructure were found at six weeks after the surgery, and the graft-bone and host-bone have been integrated completely without obvious boundary at 24 weeks postoperatively. Histomorphologic study showed that the amount of bone within pores of the porous gradient hydroxyapatite/zirconia composites increased continuously with a prolonged implantation time, and that partial composites were degradated and replaced by new-bone trabeculae. There was no significant difference between subgroups (P > 0.05) in the ultimate compressive strengths. CONCLUSION: New porous gradient hydroxyapatite/zirconia composites can promote the repair of bony defect, and induce bone tissue to ingrow into the pores, which may be applied widely to the treatment of bony defect in the future.

[Treatment of low lumbar degenerative disease with unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation].

OBJECTIVE: To explore the operative skills and effect of unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation in treating degenerative low lumbar disease. METHODS: From January 2009 to December 2011,22 patients with degenerative low lumbar disease were treated with transforaminal lumbar interbody fusion, during the operations, unilateral pedicle screw and contralateral percutaneous transfacet screw fixation were performed. There were 16 males and 6 females, aged from 32 to 71 years old with an average of (51.1 ± 10.6) years, including single segment in 20 cases and two segments in 2 cases. Clinical effects were evaluated according to visual analogue score (VAS) and Oswestry Disability Index (ODI). RESULTS: All patients were followed up from 1 to 2.5 years with an average of 18 months. One case complicated with leakage of cerebrospinal fluid after operation and 1 case with lower limb pain of decompression-side on the 3rd day after operation. Twenty-two patients got bony fusion. There were no instability and evidence of instrument failure during follow-up. The VAS and ODI score decreased from preoperative 8.24 ± 0.72, 36.72 ± 6.84 respectively to 3.18 ± 0.66, 4.36 ± 1.12 at the final follow-up (P < 0.05). CONCLUSION: Unilateral pedicle screw combined with contralateral percutaneous transfacet screw fixation is safe and feasible surgical technique in treating low lumbar degenerative disease. It has advantages of little trauma, rigid fixation, high fusion rate, and less complication. etc.