OBJECTIVETo study the effect of disc degeneration on the structural property distributions in the cervical vertebral endplates.

METHODSA 2 mm-diameter hemispherical indenter was used to perform indentation tests at 0.03 mm/s to the depth of 2 mm at 20 normalized locations in 50 bony endplates of intact human cervical vertebrae (C2 approximately C7). The resulting load-displacement curves were used to extract the failure load and stiffness of each test site. Grade of disc degeneration was determined using Nachemson's grading scale. One-way ANOVA, factorial analyses, SNK tests and correlate analyses were used to analyze the result data.

RESULTSBoth the failure load and stiffness decreased with disc degeneration in the cervical endplates (P <0.001, both), and correlated significantly with the disc degeneration (rs=-0.429 and rs=-0.244, respectively). Only the distribution of superior cervical endplate changed with disc degeneration, but that of inferior cervical endplate changed little.

CONCLUSIONSThe structural property distributions in the cervical vertebral endplates change significantly in the degenerated discs. It suggests that disc degeneration is an important factor to evaluate the intervertebral implant subsidence in anterior cervical fusion.

Biomechanical Phenomena ; Cervical Vertebrae ; physiopathology ; Compressive Strength ; physiology ; Humans ; Intervertebral Disc ; physiology ; Intervertebral Disc Displacement ; physiopathology ; Weight-Bearing ; physiology

As a common disease in clinical, the treatment of lumbar disc herniation (LDH) focused on local intervertebral disc, such as surgery and other interventional therapy treatment, but postoperative complications and recurrence rate has been a difficult problem in the field of profession. With the development of spine biomechanics and anatomy, researches on lumbar herniation also increased. Researchers discovered that the incidence and prognosis of LDH were inseparable with local muscle and soft tissue. As the deep paraspinal muscles, multifidus muscle plays an important role to make lumbar stability. Its abnormal function could reduce the stable of lumbar spine, and the chronic lumbar disease could also lead to multifidus muscle atrophy.
Animals ; Humans ; Intervertebral Disc Displacement ; physiopathology ; surgery ; Lumbosacral Region ; physiopathology ; surgery ; Paraspinal Muscles ; physiopathology

A geometrical model of L4-L5 lumbar segment was constructed using a three-dimensional graphics software. Four conditions of the degenerated discs, i. e. light degeneration, moderate degeneration, severe degeneration and complete excision degeneration, were simulated with loading situations using finite element method under the condition of appropriate computational accuracy. By applying a vertical load of 378.93 N on L4 vertebral plate, stress nephograms on joint isthmus under four different working conditions were obtained. The results showed that the contacted area of facet joint was influenced by the degree of intervertebral disc degeneration level, which influenced the mises stress on joint isthmus. It was proved that joint isthmus was the important pressure-proof structure of the back of lumbar vertebra, and the stress values and distribution were related to structural stiffness of the back of lumbar vertebra as well as the contact area of facet joint. The conclusion could be the theoretical reference for the analysis of spinal biomechanics and artificial disc replacement as well.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Intervertebral Disc ; pathology ; Intervertebral Disc Degeneration ; Lumbar Vertebrae ; physiopathology ; Models, Anatomic ; Pressure ; Zygapophyseal Joint

Intervertebral disc degeneration is considered as a primary cause of clinical low back pain, however the molecular mechanism is not clear yet. Recently, researches on the molecular basis of intervertebral disc degeneration have become a hotspot. The special structure and biomechanics properties of the disc contribute to its propensity toward degeneration. Intervertebral disc degeneration is associated with the changes of the cytological behavior,including the increase in cell death and the degradation of extracellular matrix. However, the mechanism of cell death including cell apoptosis and autophagy in intervertebral disc degeneration remains unclear. Further study on the molecular mechanism of intervertebral disc degeneration is the foundation of improving and treating the intervertebral disc degeneration in the future. Although some progresses are made in the aspect of biological study, the biological environment of intervertebral disc itself is still a challenge for the development of biological treatment. This article is to review the latest advance on the biological characteristics of normal intervertebral disc and the cell death in the process of the intervertebral disc degeneration.
Animals ; Apoptosis ; Cell Death ; Extracellular Matrix ; metabolism ; Humans ; Intervertebral Disc ; cytology ; metabolism ; Intervertebral Disc Degeneration ; metabolism ; physiopathology

OBJECTIVETo compare biological characteristics between nucleus pulposus and annulus fibrosus cells in vitro model.

METHODSFive New Zealand white rabbits (2 to 3 kg, either gender) were isolated nucleus pulposus and annulus fibrosus under sterilized condition, then cultured in nutrient solution with 15% FBS and DMEM/F12 (1:1) by enzyme digestion combined with tissue block method. When 90% cells fused, subcultring were performed. Cell morphology were observed by inverted phase contrast microscope, cell viability were detected by trypan blue staining, histological were observed by a toluidine blue and HE staining, cell proliferation were tested by MTT method, then the cell morphology, viability, proliferation between nucleus pulposus and annulus fibrosus were compared.

RESULTSThere were no obviously differences between nucleus pulposus and annulus fibrosus in original and the first strain. Physalides were appeared in annulus fibrosus on the second generation. The strapping time was later, and activity was lower in nucleus pulposus than annulus fibrosus. The growth of cell proliferation in nucleus pulposus was lower than annulus fibrosus from the ninth day.

CONCLUSIONThe cell activity in annulus fibrosus is higher than nucleus pulposus. Digenerative disc disease may caused by recession of nucleus pulposus,local biomechnical changes, furether caused structure change and function loss of annulus fibrosus.

Animals ; Cell Proliferation ; Cell Survival ; Disease Models, Animal ; Female ; Humans ; Intervertebral Disc ; cytology ; Intervertebral Disc Degeneration ; physiopathology ; Male ; Rabbits

OBJECTIVETo study the biomechanical relationship between iliac rotation displacement and L(4,5) disc degeneration, and to provide clinical evidences for the prevention and treatment of L(4,5) disc degeneration and herniation.

METHODSFrom March 2012 to February 2014,68 patients with lumbar disc herniation combined with sacroiliac joint disorders were selected. Among them, 42 patients with L(4,5) disc herniation combined with sacroiliac joint disorders included 22 males and 20 females, ranging in age from 19 to 63 years old, with an average of (51.78 +/- 20.18) years old, and the duration of the disease ranged from 1 to 126 months with an average of (11.18 +/- 9.23) months. Twenty-six patients with L5S1 disc herniation combined with sacroiliac joint disorders included 11 males and 15 females, ranging in age from18 to 65 years old with an average of (45.53 +/- 27.23) years old, and the duration of the disease ranged from 0.5 to 103 months with an average of (11.99 +/- 12.56) months. Sixty-eight anteroposterior lumbar radiographs, 68 lateral lumbar radiographs,and 68 pelvic plain films were taken. The degree of lumbar scoliosis, pelvic tilt,and disc thickness were measured. The correlation between pelvic tilt and lumbar scoliosis ,lumbar scoliosis and disc thickness were studied by using linear and regression methods. The hiomechanical analysis was performed.

RESULTSThere was a positive correlation between pelvic tilt and lumbar scoliosis in patients with L(4,5) disk herniation (R=0.49, P=0.00). There was a causal relationship and good linear proportional relationship (Y=3.05+1.07X, P=0.00) in the two variables. There was a negative correlation between lumbar scoliosis and intervertebral space in male patients with L (4,5) disk herniation (R = -0.50, P=0.01). There was a causal relationship and good linear proportional relationship in the two variables (Y=13.09-0.27X, P=0.02). But there was a positive correlation between lumbar scoliosis and intervertebral space in male patients with L5S1 disk herniation (R=0.46, P=0.04).

CONCLUSIONIliac rotational displacement are closely related with L(4,5) disc degeneration and herniation in biomechanics. A new concepts and therapeutic approach is provided for clinical treatment of chronic and refractory herniation of L(4,5) disc in patients

Adult ; Biomechanical Phenomena ; Female ; Humans ; Intervertebral Disc Degeneration ; physiopathology ; Intervertebral Disc Displacement ; physiopathology ; Lumbar Vertebrae ; physiopathology ; Male ; Rotation ; Sacroiliac Joint ; chemistry ; physiopathology ; Young Adult

Disc degeneration disease (DDD) is the major cause of lower back pain, resulting in significant serious social problems and economic burdens due to its high mortality rate and disability rate. Currently available clinic treatments are inefficient for solving spinal structure and function insufficiency caused by the DDD, especially for patients with degenerated or broken anulus fibrosus. Tissue engineering provides a promising and available strategy to regenerate a new anulus fibrosus with complete bio-functions. This review following primary introduces the current research progress and the potential development orientation of tissue engineering anulus fibrosus.
Animals ; Humans ; Intervertebral Disc ; physiopathology ; Intervertebral Disc Degeneration ; physiopathology ; therapy ; Lumbar Vertebrae ; physiopathology ; Mesenchymal Stem Cell Transplantation ; methods ; Tissue Engineering ; methods ; Tissue Scaffolds

This study examined the biological characteristics of normal and degenerated rabbit nucleus pulposus (NP) cells in vitro in order to provide seed cells for intervertebral disc (IVD) tissue engineering. A total of 8 adult New Zealand white rabbits underwent annulus puncture to establish models of intervertebral disc degeneration (IDD). Four weeks later, normal and degenerated NP cells were obtained. Cell morphology was observed by light and electron microscopy. Cell viability was measured by MTT assay. Cell cycle and expression of extracellular matrix (ECM)-related genes (aggrecan and type II collagen) were determined by using flow cytometry and RT-PCR respectively. The growth curve of normal NP cells showed that the cells at passage 4 tended to slowly grow on the fifth day of culture. The density of normal NP cells at passages 5 to 7 was significantly less than that of the first-passage cells 2 or 3 days after seeding (P<0.05). The degenerated NP cells at passage 3 showed slow growth at 4th day. After 5 passages, the degenerated NP cells assumed stagnant growth and the growth seemed to stop at passage 7. The MTT assay revealed that for both normal and degenerated NP cells, the absorbance (A) value at passages 4-7 was obviously decreased as compared with that at passage 1 (P<0.05). Cell cycle analysis showed that the proportion of normal NP cells at Gl phase was 65.4%±3.5%, significantly lower than that of degenerated NP cells at the same cell cycle phase with the value being 77.6%±4.8%. The degenerated NP cells were predominantly arrested at G1 phase and failed to enter S phase. The expression of type II collagen and aggrecan was significantly decreased with passaging. It was concluded that normal NP cells possessed good viability and proliferative capacity by the third passage, and they could secrete large amounts of ECM within this period. The normal NP cells may serve as seed cells for IVD tissue engineering.
Animals ; Apoptosis ; physiology ; Cell Cycle ; physiology ; Cell Proliferation ; Cell Size ; Cell Survival ; physiology ; Cells, Cultured ; Intervertebral Disc ; cytology ; physiopathology ; Intervertebral Disc Degeneration ; pathology ; physiopathology ; Rabbits ; Reference Values

OBJECTIVETo observe the histologic changes of the cervical muscles and intervertebral discs caused by dynamic dysequilibrium of frontally cervical muscles in rabbits.

METHODSThirty healthy rabbits with an average age of two years, half males and half females, the mean of weight in (2.75 +/- 0.25) kg, were divided randomly into model group and the sham operation group with fifteen rabbits in each group. The hibateral sternocleidomastoid muscles of rabbits in the model group were shortened by medical pipe to estabish the new animal model (the model was cervical dynamic dysequilibrium); and in the sham operative group, only exposed hibateral sternocleidomastoid muscles by operation. At the same time after two months, the histologic changes of the cervical muscles and intervertebral discs in all rabbits were observed, meanwhile, the myofibrillar amount and its cross section area were compared between two groups.

RESULTSAfter operation, the cervical muscles and intervertebral discs had significant change in model group, but no obvious change in sham operative group. The myofibrillar amount of frontal cervical muscles and back cervical muscles in model group was obviously lower than that of sham operative group (P < 0.05); likewise, the myofibrillar cross section area in model group was obviously lower than that of sham operative group (P < 0.05); the frontal cervical muscles was obviously change than the back cervical muscles.

CONCLUSIONThe cervical dynamic dysequilibrium caused by crispation of frontal cervical muscles can lead to pathologic degeneration of cervical muscles and intervertebral discs. The study may provide experimental proof for early cervical spondylopathy.

Animals ; Female ; Intervertebral Disc ; pathology ; Male ; Neck Muscles ; pathology ; physiology ; Rabbits ; Spasm ; pathology ; physiopathology

OBJECTIVETo investigate the operative management and surgical techniques for lumber disc herniation (LDH) in aged patients (>or=65 years).

METHODSFrom 2005 to 2010,the data of 43 patients with LDH underwent surgical treatment were retrospectively analyzed. There were 25 males and 18 females,aged from 65 to 70 years old with an average of 67.6 years. The course of disease was from 6 weeks to 7 years with an average of 10.2 years. Fenestratiodn discectomy or extended fenestration discectomy and unilateral or bilateral fenestration were used according to the conditions of location,type of herniated macleos polposus and nerve root compression. Among the patients,the nerve root canal was enlarged,hyperplastic osteophyma and soft tissue were removed, bilateral articular process was reserved in order to maintain the stability of the lumbar segment.

RESULTSAll the patients were followed up from 1.2 to 5.2 years. According to the criteria of HU you-gu, 25 cases got excellent results, 15 good, 2 fair and 1 poor. No infection or nerve injury was found. Nerve function of patients had a normal or near normal recovery.

CONCLUSIONFor the treatment of LDH in aged patents,it is key that reasonably choose the operative method, completely remove the hyperplasy of diseased region and enlarge the nerve root canal, thoroughly loose the nerve root.

Aged ; Female ; Humans ; Intervertebral Disc Displacement ; physiopathology ; surgery ; Lumbar Vertebrae ; surgery ; Male ; Retrospective Studies