腰骶椎前路融合笼的设计及临床应用

目的　研制出腰骶椎前路融合笼 (AnteriorFusingCage-AFC)并选定相应的放置方式用于下腰痛患者的治疗。 方法　1、通过在人尸椎骨及牛椎骨标本上的生物力学试验 ,人尸椎骨的解剖学测量 ,结合手术要求 ,设计了AFC及相应辅助器械 ,并筛选出相应的放置方式。 2、将该技术用于 14例下腰痛患者的治疗。结果　 1、AFC直径≈ 1/ 2 (a +p) +12～ 16 (mm) ,AFC长度≈S - 6 -S×滑脱百分比。 2、放置方式为在L5S1间隙取正中 1枚AFC放置法及L4.5间隙取左前外斜向 1枚AFC放置法。 3、随访 2 4～ 4 5个月 ,初步结果满意。结论　AFC有助于施术节段的融合与稳定 ,增加椎间隙高度 ,不需术后长时间石膏外固定 ,该技术较国外同类方法简便安全     

椎间盘源性腰痛的诊断与治疗

目的探讨腰椎间盘源性疼痛的诊断方法及采用前路经腹膜外入路椎间盘切除人工椎间盘置换或椎间cage植骨融合的临床疗效。方法35例经保守治疗无效的椎间盘源性腰痛患者接受手术治疗。椎间盘源性腰痛的诊断标准为：（1）腰部及下肢疼痛的部位与神经根定位不符；（2）症状反复发作，病程在半年以上；（3）MRI病变椎间盘T2加权像低信号；（4）椎间盘造影阳性，相邻节段为阴性对照；（5）关节突关节封闭除外关节突关节退变引起的疼痛。患者年龄25-67岁，平均43．6岁。L4-5 14例，L5S1 16例，L4-5和L5S1双间隙5例。前路经腹膜外入路椎间盘切除后行人工椎间盘置换13例16个椎间盘，椎间cage融合22例24个椎间盘。术后3-7天下地活动。腰围固定3个月。结果所有患者随访6～26个月，平均18个月。术后腰痛及下肢痛症状明显缓解，均恢复正常生活或工作。VAS评分由术前平均72分，降至术后18分，随访6个月时6．5分。ODI评分由术前平均21．5分。降至随访6个月时3分。椎间隙高度从术前平均9．5mm增加至术后13．5mm。手术时间70-120min，出血量100-400ml。随访时未发现肠梗阻、逆行射精和假体位置移动。结论椎间盘源性腰痛由于临床和影像学表现不典型，常被误诊或漏诊，可结合腰椎MRI及椎间盘造影进行诊断。腰椎前路椎间盘切除人工椎间盘置换或椎间cage融合是治疗椎间盘源性腰痛的有效选择。     

Modic改变在腰腿痛病例中的分布及相关因素分析

目的探讨腰椎终板Modic改变在腰腿痛病例中的的临床分布特点，并探讨发生Modic改变的相关因素。方法选择2005年一年内因腰痛或坐骨神经痛行腰椎MR检查和常规X线检查的患者1223例，分析腰椎MRI中终板Modic改变在椎间盘节段、年龄和椎间盘退变分类中的分布特点及其相关因素。结果1223例6115个腰椎椎间盘中，257例（21．0％）320个椎间盘（5．2％）邻近终板发生M0dic改变，其中Ⅰ型48例（3．9％）51个椎间盘（0．8％），Ⅱ型206例（16．8％）266个椎间盘（4．3％）、Ⅲ型3例（0．2％）3个椎间盘（0．05％）。椎间盘节段L5S1 168个、L4-5 95个、L3-4 29个、L2-3 18个、L1-2 10个，发生率分别为13．7％、7．8％、2．4％、1．5％、0．8％。突出、脱出和滑脱病例发生率较高（辟0．00）。女性发生率高于男性（P=0．005）。40岁以上是Modic改变发生较多的年龄段（P=0．001）。椎间盘退变程度、椎间盘节段与年龄均和Modic改变具有显著相关性（P=0．000）。回归方程为Y=-5．955＋0．198A＋1．528L＋1．883D（Y为M0dic改变，A为年龄，L为椎间盘节段，D为椎间盘退变程度），P=0．000，EXP值：D=6．571，L=4．609，A=1．220。结论腰椎终板Modic改变和椎间盘退变、椎间盘节段和年龄之间存在相关关系，椎间盘退变是最重要的影响因素。Modic改变Ⅱ型最多，Ⅰ型次之，Ⅲ型最少；多发生于L4-5和L5S1椎间盘节段；女性高于男性；40岁以上是易发年龄。     

Backside Wear in Modern Total Knee Designs

Although modularity affords various options to the orthopedic surgeon, these benefits come at a price. The unintended bearing surface between the back surface of the tibial insert and the metallic tray results in micromotion leading to polyethylene wear debris. The objective of this study was to examine the backside wear of tibial inserts from three modern total knee designs with very different locking mechanisms: Insall-Burstein II® (IB II®), Optetrak®, and Advance®. A random sample of 71 inserts were obtained from our institution’s retrieval collection and examined to assess the extent of wear, depth of wear, and wear damage modes. Patient records were also obtained to determine patient age, body mass index, length of implantation, and reason for revision. Modes of wear damage (abrasion, burnishing, scratching, delamination, third body debris, surface deformation, and pitting) were then scored in each zone from 0 to 3 (0 = 0%, 1 = 0–10%, 2 = 10–50%, and 3 = >50%). The depth of wear was subjectively identified as removal of manufacturing identification markings stamped onto the inferior surface of the polyethylene. Both Advance® and IB II® polyethylene inserts showed significantly higher scores for backside wear than the Optetrak® inserts. All IB II® and Advance® implants showed evidence of backside wear, whereas 17% (5 out of 30) of the retrieved Optetrak® implants had no observable wear. There were no significant differences when comparing the depth of wear score between designs. The locking mechanism greatly affects the propensity for wear and should be considered when choosing a knee implant system.Key words: polyethylene, wear, knee, backside, back surface, locking mechanism     

Modic changes following lumbar disc herniation

Only a small proportion (20%) of patients with LBP can be diagnosed based on a patho-anatomical entity. Therefore, the identification of relevant subgroups, preferably on a patoanatomical basis, is strongly needed. Modic changes have been described by several authors as being closely linked with LBP. The aims of this study were to describe the prevalence of Modic changes, their development as well as their association to LBP, previous disc contour, and surgery in patients with previous severe sciatica. This is a longitudinal cohort study where the patients were recruited from an RCT comparing two active conservative treatments, the 181 patients, who at baseline had radicular pain in or below the knee; all underwent a physical examination and MRI. MRI’s, pain history and physical examination of 166 patients were obtained at follow-up 14 months later. The prevalence of Modic changes type 1 increased from 9% at baseline to 29% at follow-up. At that time, a strong association between Modic changes and non-specific LBP was noted. Apparently, Modic changes type 1 was more strongly associated with non-specific lumbar pain than Modic changes type 2. The development of new Modic changes was closely related to the level of a previous disc herniation. A lumbar disc herniation is a strong risk factor for developing Modic changes (especially type 1) during the following year. Furthermore, Modic changes are strongly associated with LBP.     

后路椎体间植骨融合术治疗下腰椎不稳

目的探讨后路椎体间植骨融合术治疗下腰椎不稳的手术技术并评价其应用价值.方法对明确诊断为下腰椎不稳的32例患者进行后正中入路下的椎管狭窄减压手术,椎弓根螺钉植入并行椎间隙撑开,双侧切除椎间盘保留侧方以及前方的纤维环,刮除终板的软骨层,植入足量的松质骨以及椎板切除物,最后植入双条三面皮质骨的髂骨块,椎弓根螺钉系统加压固定.结果平均手术时间,平均失血量较常规手术无显著差别.28例获得手术后的3个月随访,原有的神经压迫症状大部恢复,行走距离增加最为明显.椎间高度术前2.8～6.7mm,平均高度4.2mm,术后椎间高度11.8～14.3mm,平均12.6mm.在3个月随访时平均高度为10.8～13.2mm,平均11.6mm.椎间孔3个月后较术前增加6mm.27例显示椎间隙的活动度小于2°,椎体与植骨块交界处无透亮区.1例植骨块吸收,但症状改善.最常见的并发症为脑脊液漏和神经根牵拉刺激,最终缓解.结论后路椎体间植骨融合术结合椎弓螺钉系统固定治疗下腰椎不稳满足充分减压,即刻的腰椎稳定性的重建以及长期可靠骨性融合治疗的基本要素.     

The association between isoinertial trunk muscle performance and low back pain in male adolescents

The literature reports inconsistent findings regarding the association between low back pain (LBP) and trunk muscle function, in both adults and children. The strength of the relationship appears to be influenced by how LBP is qualified and the means by which muscle function is measured. The aim of this study was to examine the association between isoinertial trunk muscle performance and consequential (non-trivial) low back pain (LBP) in male adolescents. Healthy male adolescents underwent anthropometric measurements, clinical evaluation, and tests of trunk range of motion (ROM), maximum isometric strength (STRENGTH) and peak movement velocity (VEL), using an isoinertial device. They provided information about their regular sporting activities, history and family history of LBP. Predictors of “relevant/consequential LBP” were examined using multivariable logistic regression. LBP status was reassessed after 2 years and the change from baseline was categorised. At baseline, 33/95 (35%) subjects reported having experienced consequential LBP. BMI, a family history of LBP, and regularly playing sport were each significantly associated with a history of consequential LBP (p < 0.05). 85/95 (89%) boys participated in the follow-up: 51 (60%) reported no LBP at either baseline or follow-up (never LBP); 5 (6%) no LBP at baseline, but LBP at follow-up (new LBP); 19 (22%) LBP at baseline, but none at follow-up; and 10 (12%) LBP at both time-points (recurrent/persistent LBP). The only distinguishing features of group membership in these small groups were: fewer sport-active in the “never LBP” group); worse trunk mobility, in the “persistent LBP” group, lower baseline sagittal ROM in the “never LBP” and “new LBP” (p < 0.05). Regular involvement in sport was a consistent predictor of LBP. Isoinertial trunk performance was not associated with LBP in adolescents.     

Changes in paraspinal muscles and their association with low back pain and spinal degeneration: CT study

The objectives of the study were to evaluate the association between lumbar paraspinal muscle density, evaluated on computed tomography (CT) and age, sex and BMI; and to evaluate the association of those changes with low back pain (LBP) and spinal degeneration features in a community-based sample. This study was an ancillary project to the Framingham Study. A sample of 3,529 participants aged 40–80 years had a CT scan performed to assess aortic calcification. 187 individuals were randomly enrolled in this study. LBP in the last 12 months was evaluated using self-report questionnaire. Density (in Hounsfield units) of multifidus and erector spinae was evaluated on CT. The prevalence of intervertebral disc narrowing, facet joint osteoarthritis (FJOA), spondylolysis, spondylolisthesis and spinal stenosis were also evaluated. We used linear regression models to examine the association of paraspinal muscles density with age, sex, BMI, LBP, and spinal degeneration features. The results show that in our study, men have higher density of paraspinal muscles than women, younger individuals have higher density than older ones and individuals with lower weight have higher muscle density than overweight. No differences between individuals with and without LBP were found. Significant association was found between L4 multifidus/erector spinae density and FJOA at L4–L5; between multifidus at L4 and spondylolisthesis at L4–5; and between erector spinae at L4 and L5 with disc narrowing at L4–5 and L5–S1, respectively. We conclude that the paraspinal muscle density decreases with age, and increases BMI. It is associated with at some levels FJOA, spondylolisthesis and disc narrowing at the same level, but not associated with occurrence of LBP.     

Lumbar posterolateral fusion inhibits sensory nerve ingrowth into punctured lumbar intervertebral discs and upregulation of CGRP immunoreactive DRG neuron innervating punctured discs in rats

Degeneration of lumbar intervertebral discs is thought to be a cause of low back pain. Studies have found that a cause of discogenic low back pain is intervertebral disc inflammation and axonal growth of afferent fibers innervating the disc. Lumbar spine fusion for chronic discogenic low back pain is considered an effective procedure. However, no study has investigated the mechanism of pain relief. We did this by applying Fluoro-Gold (FG) to the ventral aspect of the L4–L5 intervertebral discs of 40 rats. We exposed the nucleus pulposus to the annulus fibrosus in a disc punctured model. Rats were divided into 4 groups. Group A: Punctured intervertebral disc with sham posterolateral fusion (PLF) (n = 10), Group B: Punctured intervertebral disc with PLF (n = 15), Group C: Normal intervertebral disc (no puncture) with PLF (n = 10), and Group D: Normal disc (no disc puncture) with sham PLF (n = 5). Four weeks after surgery, bilateral L1–L5 dorsal root ganglia (DRGs) were stained with growth-associated protein 43 (GAP43), a marker of axonal growth, and calcitonin gene-related peptide (CGRP), a neuropeptide marker of pain. Bone union was evaluated using X-ray imaging. Of the FG-labeled neurons, the proportions of GAP43- and CGRP-immunoreactive (IR) neurons in Group A were significantly higher than in Group D (P < 0.05). The proportions of GAP43- and CGRP-IR neurons in bone union rats in Group B were significantly lower than in nonunion rats in Group B and in the rats in Group A (P < 0.05). No significant differences in GAP43- and CGRP-IR neurons were observed between bone union and nonunion rats in Group C and the rats in Group D (P > 0.05). PLF is strongly related to the downregulation of GAP43 and CGRP expression. Therefore, PLF may suppress the increase of inflammatory neuropeptides and the process of axonal growth. Moreover, these results may explain, in part, the mechanism of pain relief following lumbar spinal fusion for chronic discogenic low back pain in humans.