Cementing the apical and terminal pedicle screw applied in osteoporotic spine with lumbosacral degenerative disease: A finite element analysis / 中国组织工程研究

BACKGROUND: Cement-augmented pedicle screw is an effective fixation for osteoporotic spine, and it is important to reduce the rate of cement leakage. OBJECTIVE: To evaluate the stability of cementing the apical and terminal pedicle screw applied in osteoporotic spine with lumbosacral degenerative disease by finite element analysis. METHODS: An intact finite element model of L2-5 segment was established by using CT scan data of one normal male volunteer. After verifying the validity of the intact model, the cementing apical and terminal pedicle screw and cement-augmented pedicle screw models of double/multi-level segment fixation were established, respectively. A 150 N vertical axial pre-load was imposed on the superior surface and a 10 N·m moment was applied on the superior surface along the radial direction to simulate six different physiological motions: flexion, extension, left bending, right bending, left rotation, and right rotation. The different of range of motion, cage stress, and pedicle screw stress on fixed segments were compared between models. RESULTS AND CONCLUSION: (1) The validity showed that the range of motion of the intact model was similar to cadaveric studies in all directions. (2) The range of motion of cementing the apical and terminal pedicle screw group was slightly larger than that of cement-augmented pedicle screw group and the difference between the two groups was less than 0.15°. The two fixation methods could maintain the similar stability of the operation segment. (3) The difference of the cage stress and instrument stress was also small between the two groups. (4) These results suggest that compare with cement-augmented pedicle screw, cementing the apical and terminal pedicle screw can increase the approximate stability in double-level and multi-level segment fusion. The cementing the apical and terminal pedicle screw procedure may reduce the risk of cement leakage and patient costs, and offer a useful alternative to the cement-augmented pedicle screw procedure.

Inner-heating acupuncture of lumbar degenerative lesions based on β-catenin signaling pathway / 中国骨伤

OBJECTIVE@#By observing the effect of inner-heating acupuncture on the expression of Wnt1, Axin and β-catenin in the intervertebral disc of rats with lumbar degenerative disease and to explore the regulatory mechanism of inner-heating acupuncture on the apoptosis of annulus fibrosus cells in rats with lumbar degenerative disease.@*METHODS@#Forty SD rats were randomly divided into normal group, model group, inner heating acupuncture group and acupuncture group with 10 rats in each group. Except for normal group, all rats were modeled. Bilateral were selected for inner-heating acupuncture and acupuncture treatment. Western-bolt assay was used to detect the expression of Wnt1, Axin and β-catenin in rat intervertebral discs.@*RESULTS@#Compared with the model group, Wnt1 and β-catenin expression in annulus fibrosus cells of rats in the inner heating acupuncture group and the acupuncture group were significantly decreased(0.05).@*CONCLUSION@#Inner heating acupuncture can down regulate the expression of Wnt1 and β-catenin and up regulate the expression of Axin in annulus fibrosus of rats with lumbar degenerative desease. It is suggested that the mechanism may be to regulate the expression of related factors in the β-catenin signaling pathway, so as to achieve the goal of treating lumbar degenerative diseases.

Effect evaluation of over 5 year follow up of unilateral pedicle screw fixation with transforaminal lumbar interbody fusion for lumbar degenerative diseases / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the clinical effects of over 5 year follow up of unilateral pedicle screw fixation with transforaminal lumbar interbody fusion(TLIF) in treating lumbar degenerative diseases.</p><p><b>METHODS</b>The clinical data of 24 patients with lumbar degenerative disease underwent unilateral pedicle screw fixation with transforaminal lumbar interbody fusion from March 2007 to October 2009, were retrospectively analyzed. There were 13 males and 11 females, aged from 34 to 68 years old with an average of 52 years. Postoperative pain and functional results were analyzed by the visual analogue scale(VAS) and Oswestry Disability Index(ODI). Radiological examination was obtained for each patient to assess the height of intervertebral space, postoperative intervertebral fusion conditions and general complications.</p><p><b>RESULTS</b>All patients were followed up from 5 to 8 years with an average of 6.7 years. VAS scores of low back pain and leg pain decreased from preoperative 7.82±0.71, 8.42±1.24 to postoperative 1.87±0.81, 2.23±1.62, respectively(<0.05). ODI decreased from preoperative(53.42±8.26)% to postoperative(12.45±7.67)%(<0.05). Postoperative intervertebral space height in different segments were improved than preoperative(<0.05), but in final follow up it was decreased than 3 months after operation(<0.05). There was no significant difference in the postoperative intervertebral space height between the operated side and non operated side. But at final follow up, the intervertebral space height of non operated side was obviously loss. At final follow up, the fusion rate was 95.8%. The incidence of adjacent segment degeneration was 45.8%. The paraspinal muscle fibrosis incidence was 8.3%. No complications such as secondary scoliosis, intervertebral height loss, cage slippage, screw loosening and internal fixation breakage were found.</p><p><b>CONCLUSIONS</b>Unilateral pedicle screw fixation with TLIF is a satisfactory method and can obtain good effects in treating lumbar degenerative diseases according to over 5 year follow up, however, its indications should be well considered. But the problems such as intervertebral space height of operated side loss and adjacent segment degeneration after unilateral pedicle screw fixation need further clinical study.</p>

Cantilever Transforaminal Lumbar Interbody Fusion for Upper Lumbar Degenerative Diseases (Minimum 2 Years Follow Up)

PURPOSE: To evaluate the clinical outcomes of cantilever transforaminal lumbar interbody fusion (c-TLIF) for upper lumbar diseases. MATERIALS AND METHODS: Seventeen patients (11 males, 6 females; mean +/- SD age: 62 +/- 14 years) who underwent c-TLIF using kidney type spacers between 2002 and 2008 were retrospectively evaluated, at a mean follow-up of 44.1 +/- 12.3 months (2 year minimum). The primary diseases studied were disc herniation, ossification of posterior longitudinal ligament (OPLL), degenerative scoliosis, lumbar spinal canal stenosis, spondylolisthesis, and degeneration of adjacent disc after operation. Fusion areas were L1-L2 (5 patients), L2-L3 (9 patients), L1-L3 (1 patient), and L2-L4 (2 patients). Operation time, blood loss, complications, Japanese Orthopaedic Association (JOA) score for back pain, bone union, sagittal alignment change of fusion level, and degeneration of adjacent disc were evaluated. RESULTS: JOA score improved significantly after surgery, from 12 +/- 2 to 23 +/- 3 points (p < 0.01). We also observed significant improvement in sagittal alignment of the fusion levels, from - 1.0 +/- 7.4 to 5.2 +/- 6.1 degrees (p < 0.01). Bony fusion was obtained in all cases. One patient experienced a subcutaneous infection, which was cured by irrigation. At the final follow-up, three patients showed degenerative changes in adjacent discs, and one showed corrective loss of fusion level. CONCLUSION: c-TLIF is a safe procedure, providing satisfactory results for patients with upper lumbar degenerative diseases.

Lumbar Total Disc Replacement

In surgical treatments of degenerative lumbar disc disease, arthrodesis is well known to be a gold standard; however various disadvantages related to elimination of the segmental motion and the procedures of fusion surgery have become a matter of concern. To this end, total disc replacement (TDR) was recently highlighted as one of alternative surgical modalities and being used widely. However, although it has been almost 10 years since lumbar TDR was int- roduced and actively used in the clinic, its clinical usefulness is still in dispute. The authors review and put together the history, biomechanics, and currently available prostheses of lumbar TDR in the present study. Some of the recent preliminary, mid-term and long-term clinical results of lumbar TDR in degenerative lumbar spine diseases are also reviewed. Lastly, we look out over the future prospect of lumbar TDR.