Objective
To explore the relationship between imbalance in sagittal plane as well as structural factors and lumbar degenerative disease.
Methods
Patients diagnosed between July 2012 and May 2015 were divided into 4 groups according to corresponding diagnostic criteria: lumbar disc herniation group (LDH), lumbar disc protrusion group (LDP), degenerative lumbar spondylisthesis group (DLS) and nonspecific low back pain group (NLBP); 40 patients were included in each group according to their visiting time. All patients underwent X-ray, CT, and MRI. Sagittal parameters and evaluate degeneration level of structural factors were measured, and the difference among the groups were analyzed.
Results
There was statistical significance in differences of pelvic incidence (PI) and lumbar lordosis (LL) among 4 groups (P<0.05). Average PI was followed in descending order: DLS, LDP, NLBP, and LDH; average LL was followed in descending order: DLS, NLBP, LDP, and LDH. There was no statistical differences in sacral slope and pelvic tilting among 4 groups (P>0.05). The difference in the level of lumbar disc degeneration between NLBP group (which had slightest lumbar disc degeneration) and the other groups was significant (P<0.001) while no statistical differences in level and rate of lumbar disc degeneration among the other three groups was found (P>0.05). As to the level of lumbar zygapophyseal joint degeneration, there was statistical differences between NLBP group (which had the lowest level of lumbar zygapophyseal joint degeneration) and the other groups (P<0.001) while no statistical differences in the grade of lumbar zygapophyseal joint degeneration among the other three groups (P>0.05). There was statistical differences in the rate of lumbar zygapophyseal joint degeneration between LDH and DLS group (χ2=11.429,P=0.001).
Conclusions
Vertical lunbar spine is combined with LDH of which the level of lumbar zygapophyseal joint degeneration is minimized, while crooked lunbar spine is combined with DLS of which the level of lumbar zygapophyseal joint degeneration is maximization. NLBP has the lowest level of degeneration of lumbar disc and lumbar zygapophyseal joint degeneration.
Objective To explore the influence of discectomy and artificial disc replacement on the upper lumbar facet joint and to provide the evidence for use of artificial disc replacement. Methods Under the loads of 200-2 000 N axis pressure and 1-10 Nm back-extending/side-bending pressure on the 7 fresh adult corpses, the pressure of L3,4facet joint was measured in the case of L4,5disc integrity, discectomy and artificial disc replacement and the statistical analysis was done.ResultsUnder the same load (axis, back-extending/side bending), there were significant differences (Plt;0.01) in the pressure of upper lumbar facet jointboth between disc integrity and discectomy and between discectomy and artificial disc replacement, and there was no difference(Pgt;0.05) between disc integrity and artificial disc replacement. Conclusion The stress ofupper lumbar facet joint reduced after discectomy, it implies that simply discectomy may change biomechanics of lumbar and lead to secondary lumbar structure degeneration. The stress of upper lumbar facet joint is close to the normal value after artificial disc replancement, it implies that artificial disc replacement may protect lumbar structure. It provides some biomechanics foundation and evidence for artificial disc replacement.
The lumbar intervertebral disc exhibits a complex physiological structure with interactions between various segments, and its components are extremely complex. The material properties of different components in the lumbar intervertebral disc, especially the water content (undergoing dynamic change as influenced by age, degeneration, mechanical loading, and proteoglycan content) - critically determine its mechanical properties. When the lumbar intervertebral disc is under continuous pressure, water seeps out, and after the pressure is removed, water re-infiltrates. This dynamic fluid exchange process directly affects the mechanical properties of the lumbar intervertebral disc, while previous isotropic modeling methods have been unable to accurately reflect such solid-liquid phase behaviors. To explore the load-bearing mechanism of the lumbar intervertebral disc and establish a more realistic mechanical model of the lumbar intervertebral disc, this study developed a solid-liquid biphasic, fiber-reinforced finite element model. This model was used to simulate the four movements of the human lumbar spine in daily life, namely flexion, extension, axial rotation, and lateral bending. The fluid pressure, effective solid stress, and liquid pressure-bearing ratio of the annulus fibrosus and nucleus pulposus of different lumbar intervertebral discs were compared and analyzed under the movements. Under all the movements, the fluid pressure distribution was closer to the nucleus pulposus, while the effective solid stress distribution was more concentrated in the outer annulus fibrosus. In terms of fluid pressure, the maximum fluid pressure of the lumbar intervertebral disc during lateral bending was 1.95 MPa, significantly higher than the maximum fluid pressure under other movements. Meanwhile, the maximum effective solid stress of the lumbar intervertebral disc during flexion was 2.43 MPa, markedly higher than the maximum effective solid stress under other movements. Overall, the liquid pressure-bearing ratio under axial rotation was smaller than that under other movements. Based on the solid-liquid biphasic modeling method, this study more accurately revealed the dominant role of the liquid phase in the daily load-bearing process of the lumbar intervertebral disc and the solid-phase mechanical mechanism of the annulus fibrosus load-bearing, and more effectively predicted the solid-liquid phase co-load-bearing mechanism of the lumbar intervertebral disc in daily life.
Objective To study the changes of blood flow of the already-compressed cauda equina under dynamic burden, high frequency stimulation (HFS) and increased additional compression, and to clarify the mechanism of neurogenic intermittent claudication. Methods Thirty SD rats were divided into 5 groups, 6 in each. All groups were operated with laminectomy of the fifth lumbar verfebra. One hour after the measurement of blood flow,in 4experimental groups, the silicon sheets were inserted into the spinal canal of L4 and L6 to cause double level compression of cauda equina by 30%. Two hours after onset of compression, no dynamic burden was introduced to the subjects of the experimental group 1. Only HFS was introduced to the subjects of the experimental group 2 for 6 minutes. Both HFS and increased additional compression were introduced to the subjects of the experimental group 3 for 6 minutes. While only increased additional compression was introduced to the subjects of the experimental group 4 for 6 minutes. The subjects of control group only underwent laminectomy of the fifth lumbar vertebra and HFS 6 minutes. The blood flow of cauda equina was measured with laser Doppler flowmeter. Results In the first 2 hours, there was no significant change of cauda equina blood flow in the control group. During the time of HFS, the blood flow increased significantly to 186.4%±31.5% of initial value (Plt;0.05). In the experimental group 1, there was no blood flow change during the period of dynamic burden（110.4％±7.5％，Pgt;0.05）. After introduction of dynamic burden, there was no blood flow changes in the experimental group 2 (111.6％±17.6％，Pgt;0.05). The blood flow in the experimental group 3 decreased to 65.3%±10.7% of initial value (Plt;0.05); and the blood flow in the experimental group 4 decreased to 60.1%±9.2% of initial value (Plt;0.01). There was no significant difference between the experimental groups 3 and 4 (Pgt;0.05). Conclusion The results above show that during the period of increased impulse transmission, double level compression of cauda equina may limit the increase of blood flow, which maycause relative ischemia. If there is increased additional compression along with increased impulse transmission, the blood flow will decrease significantly, which will cause absolute ischemia.
In order to investigate the mechanical response of lumbar vertebrae during gait cycle in adolescents with idiopathic scoliosis (AIS), the present study was based on computed tomography (CT) data of AIS patients to construct model of the left support phase (ML) and model of the right support phase (MR), respectively. Firstly, material properties, boundary conditions and load loading were set to simulate the lumbar vertebra-pelvis model. Then, the difference of stress and displacement in the lumbar spine between ML and MR was compared based on the stress and displacement cloud map. The results showed that in ML, the lumbar stress was mostly distributed on the convex side, while in MR, it was mostly distributed on the concave side. The stress of the two types of stress mainly gathered near the vertebral arch plate, and the stress of the vertebral arch plate was transmitted to the vertebral body through the pedicle with the progress of gait. The average stress of the intervertebral tissue in MR was greater than that in ML, and the difference of stress on the convex and convex side was greater. The displacement of lumbar vertebrae in ML decreased gradually from L1 to L5. The opposite is true in MR. In conclusion, this study can accurately quantify the stress on the lumbar spine during gait, and may provide guidance for brace design and clinical decision making.
OBJECTIVE To observe the effects of sodium hyaluronate on nerve root adhesion after operation of lumbar disc protrusion (LDP). METHODS From April 1996 to June 2001, 152 cases with LDP were performed the removal of nucleus pulposus under endoscope. After operation, 2 ml of sodium hyaluronate were injected. The clinical results were evaluated by clinical symptom, straight leg raising test, patient’s satisfaction degree and back pain. RESULTS All the patients were followed for 1 month to 3 years. The average angle of straight leg raising test increased from 26 degree preoperatively to 62 degree postoperatively. The patient’s pain were markedly relieved. Patient’s satisfactory degree were 86.8%. CONCLUSION The injection of sodium hyaluronate after operation of LDP has effect on preventing postoperative nerve root adhesion.
Objective To investigate the cl inical outcomes of one stage debridement and closed-suction drainage for treatment of infection after lumbar instrumentation. Methods Between June 2002 and March 2008, 12 patients with infection after lumbar instrumentation were treated with one stage debridement and closed-suction drainage, including 9 males and 3females and aging 35-68 years (48.5 years on average). The disease duration varied from 7 days to 183 days (56 days on average). The segments of internal fixation included 7 cases single segment at levels of L4, 5, 4 cases of double segments at levels of L 4, 5, L5, S1 (2 cases), and L3, 4, L4, 5 (2 cases), and 1 case of three segments at levels of L3, 4, L4, 5, L5, S1. Two patients were treated with internal fixator removal. Results The bacterial culture results of intervertebral discs were positive in 8 cases for Staphylococcus aureus and in 3 cases for Enterobacter cloacae, negative in 1 case. Primary healing of incisions were achieved in all cases. Twelve patients were followed up 18-53 months (34.7 months on average). The white blood cell count, erythrocyte sedimentation rate, and C reactive protein significantly decreased after operation, showing significant differences at 15 days after operation when compared with those before operation (P lt; 0.05). No obvious low back pain was observed. Pathological-changed vertebra-space fused. No displacement and breakage of internal fixator occurred; in 2 patients who were given internal fixator removal, no removal of the instrumentation was performed again. The X-ray films showed that the average kyphosis decreased 0.8° at 18 months after operation. At last follow-up, the visual analogue scale score was 2 ± 1, showing significant difference (P lt; 0.05) when compared with that (10 ± 2) before operation. Conclusion One stage debridement and closed-suction drainage therapy is an effective method for treating infection after lumbar instrumentation. The operation is easy and can reduce hospitalization days.
ObjectiveTo investigate the effectiveness of retroperitoneal laparoscopic approach combined with anterolateral mini-incision for lumbar spine tuberculosis.
MethodsA retrospective analysis was made on the cl inical data of 22 patients with lumbar spine tuberculosis undergoing focus clearance, fusion, and internal fixation by retroperitoneal laparoscopic approach combined with anterolateral mini-incision between June 2006 and June 2012. There were 14 males and 8 females, with an average age of 42.6 years (range, 26-57 years) and with a mean disease duration of 7.3 months (range, 3-10 months). There were 17 patients with single-level spinal tuberculosis (L1, 2 in 3, L2, 3 in 6, L3, 4 in 4, L4, 5 in 2, and L5 in 2) and 5 patients with double-level spinal tuberculosis (L1-3 in 2 and L2-4 in 3). The preoperative Cobb's angle of lumbar spine was 5-28° (mean, 20°). In 6 patients having compression symptom, 4 cases were rated as grade D and 2 as grade C according to Frankel classification. The operative time, intraoperative blood loss, and postoperative complications were recorded. At last follow-up, the neurologic function was assessed according to Frankel grade, the Cobb's angle after operation was measured on lumbar lateral X-ray film; the efficacy was evaluated according to Nakai criteria, and the fusion was evaluated according to Suk criteria.
ResultsAll operations were successfully completed. The operation time was 110-250 minutes (mean, 140 minutes), and intraoperative blood loss was 120-280 mL (mean, 180 mL). The symptoms of femoral nerve injury and sympathetic nerve injury occurred in 1 case respectively and was relieved at 1-3 weeks after operation. All incisions healed by first intention. The patients were followed up 16-50 months (mean, 21 months). During the follow-up period, no loosening or breakage of implants and no tuberculosis recurrence were found. At last follow-up, the nerve function was recovered to grade E in the others except 1 case at grade D. The Cobb's angle was 2-16° (mean, 7.8°). According to Nakai criteria for efficacy evaluation, the results were excellent in 9 cases, good in 10 cases, and fair in 3 cases, with an excellent and good rate of 86.4%. The bony fusion rate was 95.5% (21/22) according to Suk criteria.
ConclusionRetroperitoneal laparoscopic approach combined with anterolateral mini-incision for lumbar spine tuberculosis is a safe and effective approach with minimal invasion and less complications.
OBJECTIVE: To investigate the effects of nerve root compression on dorsal root ganglia. METHODS: Following the method of Kawakami, 4/0 ribbon gut were applied around left L4-6 spinal nerve roots in 50 SD rats. Just 3 mm cranial to the dorsal root ganglia, the nerve roots were secured by two ligation node. The nerve roots of right side were as control. The L4-6 spinal cord was taken out 1, 2, 4, 8, 12 weeks after surgery, respectively. The activity of fluoride resistant acid phosphatase (FRAP) was determined by the enzyme histochemistry (Gomori method) and the image analysis technique. RESULTS: In the test side, the FRAP content of spinal dorsal horn reduced 4 weeks after operation. And there were gradually more and more decreases from 4 to 12 weeks. There was significant difference between the test side and control side (P lt; 0.01). CONCLUSION: Chronic nerve root compression causes damage to dorsal root ganglia.
Objective To elucidate the new development, structural features and appl ication of the lumbar interspinous process non-fusion techniques. Methods With the review of the development course and important research works in the field of the lumbar inter-spinous process non-fusion techniques, the regularity summary, science induction, and prospect were carried out. Results The lumbar inter-spinous process non-fusion technique was a part of non-fusion insertof spinal division posterior surface. According to the design, it could be divided into two major categories: dynamic and static systems. The dynamic system included Coflex and device for intervertebral assisted motion; the static system included X-STOP, ExtenSure and Wall is. The lumbar inter-spinous process non-fusion technique was a new technique of spinal division, it could reserve the integrated function of intervertebral disc and zygapophysial joint, maintain or recover the segmental movement to a normal level, and have no adverse effect on the neighboring segments. A lot of basic and cl inical researches indicated that lumbar inter-spinous process insert had extensive appl ication to curatio retrogression lumbar spinal stenosis, discogenic low back pain, articular process syndrome, lumbar intervertebral disc protrusion and lumbar instabil ity and so on. Conclusion With the matures of lumbar inter-spinous process non-fusion techniques and the increased study of various types of internal fixation devices, it will greatly facil itate the development of treatment of lumbar degenerative disease. But long-term follow-up is needed to investigating the long-term efficacy and perfect operation indication.
