OBJECTIVETo investigate the damage characteristics and biomechanical mechanisms of the thoracolumbar vertebral bursh fracture during the impact loading.

METHODSFrom September 2008 to October 2009, 10 fresh human thoracolumbar spine specimens were collected for experimental model and divided into two groups. Biomechanical static and dynamic impact strength test were performed respectively in two groups. The static and dynamic data from thoracolumbar vertebrae shock response in different loads were observated.

RESULTSThoracolumbar yield load was (5 280.00 +/- 354.2) N, yield displacement was (13.32 +/- 2.07) mm, the limit load was(6 590.00 +/- 249.20) N, ultimate displacement was (20.60 +/- 2.57) mm, load speed was 0.02 g, and the average limit load of dynamic mechanical properties of thoracic and lumbar vertebrae was (14 425.60 +/- 1101.52) N, the average reaction time load was (17.29 +/- 2.04) ms, the average of acceleration was (36.80 +/- 2.81) g, the dynamic displacement was (45.11 +/- 1.13) mm.

CONCLUSIONThoracolumbar vertebral burst fracture is a serious injury caused by the release of high-energy moment, the role of biomechanical forces are in a pattern of pulse change, thoracic and lumbar vertebrae present with the viscoelastic properties of biological materials.

Biomechanical Phenomena ; Cadaver ; Humans ; Lumbar Vertebrae ; injuries ; Spinal Fractures ; metabolism ; physiopathology ; Stress, Mechanical ; Thoracic Vertebrae ; injuries

We present a case of lumbosacral fracture-dislocation, which was spontaneously reduced during radiological examination. Such rapid reduction is, however, not reliable for long-term stability. We would like to report this case briefly because spontaneous reduction of lumbosacral fracture-dislocation has not been reported previously.
Adult ; Dislocations/*physiopathology/surgery ; Humans ; Lumbar Vertebrae/*injuries ; Male ; Sacrum/*injuries ; Spinal Fractures/*physiopathology/surgery

Combined Modality Therapy ; Humans ; Lumbar Vertebrae ; pathology ; physiopathology ; surgery ; Spondylolisthesis ; diagnosis ; physiopathology ; surgery ; therapy

OBJECTIVETo investigate the mid-term outcome of operation for thoracolumbar tuberculosis. METHODS : Twenty-eight patiens with thoracolumbar tuberculosis underwent one stage anterior debridement,interbody fusion with bone graft and posterior pedicle screw internal fixation treatment from July 2006 to July 2011. There were 17 males and 11 females. Total 17 patients had nerve injuries ,including 6 cases of grade B, 5 cases of grade C, 6 cases of grade D according to Frankel classification. The poisoning symptoms of tuberculosis and recovery of spinal function were observed. The bone fusion and recovery of [umbar function were evaluated.

RESULTSAll the patients were followed up ,and the duration ranged from 39 to 85 months (mean 57 months). The clinical symptoms were controlled gradually, and the thoracolumbar back pain was alleviated after operation. Among the 17 patients with complications of nerve injuries, 3 patients were improved from preoperative grade B to postoperative grade D, 3 patients were improved from preoperative grade B to postopertive E, 5 patients with preoperative grade C and 6 patients with preoperative D were almostly recovered to normal after operation. According to JOA scoring system for curative effect evaluation, the excellent and good rate at the 3rd month, the 1st year, the 3rd year and the 5th year after operation were 67.86% ,82.14% ,85.71% ,89.29% and 91.30% respectively. The results at the 6th month and the 1st year had no statistical differences compared to the results at the 3rd month (P > 0.05); but the results at the 3rd year and the 5th year were better than that at 3 months after operation (P < 0.05); and the results between 3 yesrs and 5 years after operation had no statistical differences (P < O.05). The degeneration of adjacent segments were evaluated according to the California University (Universith of California at Los Angeles , UCLA) score. The degeneration rate was 53.57% (15/28) at the 3rd year after surgery, which was better than that before surgery. Twenty-three patients were followed up for 5 years ,and the degeneration rate was 86.96% (20/23) ,which was better than those of before surgery and 3 years after surgery.

CONCLUSIONThe surgical treatment for thoracolumbar spinal tuberculosis can achieve the thorough debridement, reconstruction of spinal stability, recovery of lumbar function and promote the functional recovery of the spinal cord, which is an effective method of treatment. However, the mid term follow-up showed that more severe degenerative changes were found in the postoperative adjacent segment.

Adult ; Aged ; Female ; Humans ; Lumbar Vertebrae ; surgery ; Male ; Middle Aged ; Spinal Fusion ; methods ; Thoracic Vertebrae ; surgery ; Tuberculosis, Spinal ; physiopathology ; surgery

OBJECTIVETo compare the influence of normal and degenerative discs on stress distribution of the thoracolumbar vertebrae under destructive load, explore the biomechanical background and clinical meaning and provide theoretical basis for clinical diagnosis and treatment.

METHODSA mechanical model of thoracolumbar motion segment of normal and degenerative discs was built with a three dimensional finite element method and three stresses of vertical compression, compressive flexion and distractive flexion were comparatively analyzed.

RESULTSWith vertical compression and compressive flexion loads, the thoracolumbar motion segment of the normal disc showed that the central part of the upper and lower end-plates of the vertebrae and the central part of the trabecular bone adjacent to the end-plate were loaded with the most intensive stresses, meanwhile, the postero-lateral part of the annulus fibrosus was concentrated with stresses. Degenerative disc showed that the stress distribution of the trabecular bone was relatively averaged, the stresses of the central part adjacent to the end-plate were low, while at the same time, the stresses of the peripheral part were elevated relatively. With distraction flexion load, the stresses of the cortex bone, trabecular bone, end-plate and annulus fibrosus of the thoracolumbar vertebrae of degenerative discs were low, meanwhile, the stresses of the posterior structure of the vertebral body were relatively elevated compared with that of normal discs.

CONCLUSIONSThere is difference in influence between normal and degenerative discs on the stress distribution of the thoracolumbar vertebrae with destructive load. The transferring way of load is changed after disc degeneration.

Elasticity ; Finite Element Analysis ; Humans ; Lumbar Vertebrae ; physiology ; Spinal Injuries ; physiopathology ; Stress, Mechanical ; Tensile Strength ; Thoracic Vertebrae ; physiology

Decompression, Surgical ; Humans ; Lumbar Vertebrae ; surgery ; Spinal Fusion ; Spondylolisthesis ; diagnosis ; physiopathology ; surgery

OBJECTIVETo establish a rabbit model of intervertebral disc degeneration by puncturing the anulus fibrosus through an approach between the longissimus dorsi muscle and obliquus externus abdominis.

METHODSThe L(4/5) and L(5/6) intervetebral discs of 6 New Zealand white rabbits were punctured by an 18-gauge pin in the anterolateral annular fibrosus through an approach between the longissimus dorsi muscle and the obliquus externus abdominis with the right transverse processes of L(5) and L(6) resected; the L(2/3) discs were used as the control without exposure or needle stab, and the L(3/4) discs were subjected to sham operation with the discs exposed but not punctured after resecting the right transverse process of L(4). X-ray and magnetic resonance imaging (MRI) were performed preoperatively and at the 4th week after puncture. At 4 weeks after the operation, histological and immunohistochemical analyses of the discs were carried out.

RESULTSX-ray of the punctured discs at 4 weeks after the operation presented a significant decrease of disc height, osteophytosis formation, and end-plate stiffness; an obvious decrease of signal intensity on T(2)-weighted images was found in the puncture group but not in the control or sham-operated groups. Gross morphological inspection showed atrophy of the nucleus pulposus, which became loose, soft, and fragile with a light yellow color. Histological and immunohistochemical analyses showed a significant decrease of notochordal cells and type II collagen in the nucleus pulposus in the puncture group as compared to the control and sham-operated groups.

CONCLUSIONPuncture through the approach between the longissimus dorsi muscle and the obliquus externus abdominis allows the establishment of a reliable animal model for studying intervertebral disc degeneration.

Animals ; Disease Models, Animal ; Female ; Intervertebral Disc Degeneration ; Lumbar Vertebrae ; physiopathology ; Male ; Rabbits

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

OBJECTIVETo investigate the effects of spinal manipulation (SM) on brain functional activity in patients with lumbar disc herniation (LDH).

METHODSEleven patients with LDH were recruited in the study. All patients received 6 times of lumbar SM treatment and then clinical efficacy was evaluated. All patients received brain functional magnetic resonance imaging (fMRI) scans before and after SM treatment.

RESULTSThree subjects dropped out and 8 subjects completed the study, among whom 4 cases were effective and 4 ineffective after SM treatment. The required pressure value producing the same level (VAS 50) pain was (7.43 ± 1.47) kg and (10.53 ± 0.55) kg before and after SM treatment in effective patients(P<0.05); however, there was no significant difference in ineffective patients (P>0.05). Compared to pre-treatment level, the brain functional activity in effective patients was mainly inhibited, the inhibited areas were located in the right side of prefrontal cortex and cerebellum; while the brain functional activity was generally enhanced in ineffective patients.

CONCLUSIONSM can affect the brain functional activity of patients with LDH, the inhibited areas is mainly located in prefrontal cortex and cerebellum when SM treatment is effective.

Brain ; physiopathology ; Humans ; Intervertebral Disc Displacement ; therapy ; Lumbar Vertebrae ; pathology ; Magnetic Resonance Imaging ; Manipulation, Spinal

Anterior lumbar interbody fusion (ALIF) followed by posterior pedicle screw fixation (PSF) in a second procedure is mostly used to implement lumbar spine fusion. ALIF followed by anterior lumbar screw-plate has a lot of advantages, but its biomechanical stability requires confirmation. This study evaluated the biomechanical stability of a novel anterior lumbar locked screw-plate (ALLSP) by comparison with posterior lumbar PSF. Twelve fresh human cadaveric lumbar specimens (L4-L5) were assigned to four groups: ALIF+PSF group, ALIF+ALLSP (both fixed) group, ALIF group and an untreated control (both non-fixed) group. The first three groups received implantation of a rectangular titanium cage. Tests under axial compression, flexion, extension, lateral bending, or rotation showed that the fixed groups had significantly stronger stability than the non-fixed groups (P=0.000 for all). The ALIF+ALLSP group had significantly greater axial stiffness under applied axial compression and significantly less angular displacement under rotational forces than the ALIF+PSF group. The angular displacement of the ALIF+ALLSP group was less under flexion than that of the ALIF+PSF, and the angular displacement under lateral bending and extension was greater, but these differences were not statistically significant. In summary, the ALLSP conforms to the anterior lumbar spine and has good biomechanical stability. It is a reliable choice for enhancing the stability of ALIF.
Adult ; Bone Plates ; Bone Screws ; Female ; Humans ; Lumbar Vertebrae ; pathology ; physiopathology ; Male ; Materials Testing