髋关节置换术对股骨头坏死患者髋关节Harris评分及运动功能的影响

目的:分析髋关节置换术对股骨头坏死(osteonecrosis of the femoral head,ONFH)患者的髋关节Harris功能评分(Harris hip score,HHS)与简式Fugl-Meyer运动功能评分(Fugl-Meyer assessment scale,FMA)的影响。方法:回顾性选取于我院受诊的ONFH患者87例,按照其所用术式的不同,分为两组,传统组采用传统股骨头置换术治疗,共43例病例;研究组采用无柄解剖型人工髋关节置换术治疗,共44例,比较两组Harris评分、Fugl-Meyer运动功能评分的改变及统计并发症信息。结果:研究组Harris评分无显著差异(P0.05);治疗后,研究组Harris评分明显高于传统组(P0.05);研究组简式Fugl-Meyer运动功能显著优于传统组(P0.05);研究组并发症的发生率低于传统组(P0.05)。结论:无柄解剖型人工髋关节置换术治疗ONFH的临床疗效显著,能够改善患者髋关节功能及运动功能。     

Atypical femoral fracture in a metastatic bone disease patient six months after discontinuation of denosumab received sequentially to previous bisphosphonate therapy - A case report

Although, both bisphosphonates and denosumab are effective in reducing the risk of skeletal-related events in patients with metastatic bone disease, many concerns were being raised about the possible association between their use and atypical femoral fractures. A case of an atypical femoral fracture in a metastatic bone disease patient, six months after discontinuation of long-term zoledronic acid therapy and sequential treatment with denosumab is reported. After extensive laboratory and imaging examination, the fracture was classified as atypical and it was finally treated with discontinuation of denosumab, long cephalomedullary interlocking nailing and vitamin D administration. Sequential treatment with bisphosphonates and denosumab in patients with metastatic bone disease, may lead to an overlapping treatment effect, increasing bone suppression and the risk of atypical femoral fracture. In addition, discontinuation of denosumab may activate bone remodeling units in an area with microdamage accumulation in cortical bone caused by the previous bone suppression from the antiresorptive treatment. The activation of bone remodeling units may accelerate the occurrence of the atypical femoral fractures.     

Mechanical behavior of a total chest wall prosthesis with rib-like features

The Department of Thoracic Surgery of the National Institute of Cancer in Milan developed a new rib-cage prosthesis which tries to combine flexibility, protection and bio-compatibility. This new replacement concept has been implanted in many patients, showing cheering results in term of reconstructions simplicity, postoperative complications reduction and patients comfort. This paper investigates and discusses in detail the mechanical behavior of the innovative rib cage prosthesis. Mechanical strength and stiffness are numerically evaluated in order to asses its limits and if it is fully compatible with patients ‘normal’ life.     

Quick Construction of Femoral Model Using Surface Feature Parameterization

To facilitate the modifying of femoral surface model, by dividing the femoral mesh into surface feature units bearing medical significance based on surface feature technology, a new approach of constructing femoral models using surface feature technology is proposed. Firstly, considering of femoral anatomy, the femoral triangle mesh model generated from the averaged point-clouds is divided into several specific regions, which are called feature regions; Secondly, feature parameters are defined and the constraints among them are set up, and feature surfaces are created by skinning the contours; Finally, the adjacent feature surfaces are connected by transition surfaces, and the parametric CAD surface model of femur is constructed. Experimental results show that, with the proposed method, the surface feature model can be intuitively constructed and edited with high-level parameters. Therefore, the proposed method provides a basic tool for the design of implants and the digital restoration of incomplete femurs.     

"F"型置钉与FNS固定术对成人创伤性Pauwels III型股骨颈骨折患者疗效、骨折愈合状况及髋关节功能的影响

摘要 目的：探讨"F"型置钉与新型股骨颈内固定系统（FNS）固定术对成人创伤性Pauwels III型股骨颈骨折疗效、骨折愈合状况及髋关节功能的影响。方法：选取2019年1月-2021年12月我院收治的78例成人创伤性Pauwels III型股骨颈骨折患者作为研究对象,采用随机数字表法将患者分为对照组及研究组,各36例。对照组采用FNS进行治疗,观察组采用"F"型置钉内固定术进行治疗。观察并比较两组患者治疗疗效、术后情况、骨折愈合情况、髋关节功能、骨折复位质量及并发症发生情况。结果：观察组治疗总有效率80.56%高于对照组52.78%（P<0.05）。观察组住院时间、下地行走时间及完全负重时间均短于对照组（P<0.05）。观察组骨折愈合状况优于对照组（P<0.05）。两组患者Harris评分随时间发展而逐渐升高,且观察组术后1个月、术后3个月及术后6个月评分均高于对照组（P<0.05）。观察组骨折复位率77.78%高于对照组41.67%（P<0.05）。观察组并发症发生率低于对照组（P<0.05）。结论："F"型置钉及FNS固定术均可以治疗成人创伤性Pauwels III型股骨颈骨折患者,但"F"型置钉治疗疗效更好,并且力学稳定性能更好,术后并发症较少,利于患者术后恢复,值得在临床治疗中推广使用。     

Corticosteroid reduces blood flow to femoral heads in rabbits

Avascular necrosis of the femoral head is one of the common problems in orthopedic practice in Taiwan. The subchondral bone loses its blood supply which weakens its biomechanical support. Steroid overuse is one of many possible etiologies in reducing blood flow to the femoral head. Laser Doppler velocimeter is a precise monitor of regional blood flow of bone which is expressed in perfusion units (PU). In the control group the rabbits were injected with normal saline and there were no statistical differences between blood flow to the right hip (39.26±5.64 PU) and left hip (38.58±4.35 PU). In group B a weekly injection of methylprednisolone into rabbits for 6 weeks demonstrated the reduction of blood flow of femoral head (24.74±3.13 PU) by the laser Doppler velocimeter. The flow decreased further (15.93±2.33 PU) by 12 weeks of steroid treatment. In group C after a weekly injection of steroid for 6 weeks the flow became 31.63±4.79 PU. The steroid was then discontinued for 3 weeks and the flow was 34.6±1.34 PU. In group D the blood flow was 25.89±4.01 PU after 6 weeks of steroid treatment and we stopped the steroid for 6 weeks, the blood flow became 29.86±2.59 PU. The merit of our experiment established a model of study in avascular necrosis of the femoral head in rabbits.     

Can a reduction approach predict reliable joint contact and musculo-tendon forces?

Musculoskeletal models generally solve the muscular redundancy by numerical optimisation. They have been extensively validated using instrumented implants. Conversely, a reduction approach considers only one flexor or extensor muscle group at the time to equilibrate the inter-segmental joint moment. It is not clear if such models can still predict reliable joint contact and musculo-tendon forces during gait.Tibiofemoral contact force and gastrocnemii, quadriceps, and hamstrings musculo-tendon forces were estimated using a reduction approach for five subjects walking with an instrumented prosthesis. The errors in the proximal-distal tibiofemoral contact force fell in the range (0.3–0.9 body weight) reported in the literature for musculoskeletal models using numerical optimisation. The musculo-tendon forces were in agreement with the EMG envelops and appeared comparable to the ones reported in the literature with generic musculoskeletal models.Although evident simplifications and limitations, it seems that the reduction approach can provided quite reliable results. It can be a useful pedagogical tool in biomechanics, e.g. to illustrate the theoretical differences between inter-segmental and contact forces, and can provide a first estimate of the joint loadings in subjects with limited musculoskeletal deformities and neurological disorders.     

髋关节置换治疗高龄不稳定型股骨粗隆间骨折的临床效果观察

目的：探讨髋关节置换手术治疗高龄人群不稳定型股骨粗隆间骨折的稳定性及愈后生活质量。方法：选取我院骨科收治的110 例不稳定型股骨粗隆间骨折患者作为研究对象,随机分为两组,观察组55 例采用人工全髋关节置换术,对照组55 例采用DHS内固定治疗,观察两组患者的手术时间、手术出血量、平均住院时间、临床疗效、术后并发症及愈后生存质量。结果：观察组手术时间及手术出血量大于对照组,但患者平均卧床时间及显著短于对照组（P＜0.05）。观察组手术总有效率为87.27%,对照组手术总有效率为70.90%,观察组手术效果明显优于对照组（P＜0.05）。观察组术后并发症发生率为7.27%,显著低于对照组（25.45%）（P ＜ 0.05）。观察组患者生活质量满意度为80.00 %,明显高于对照组（61.82%）（P ＜ 0.05）。结论：髋关节置换手术能减少术中出血量、患者下地活动时间早,局部组织修复速度快,对于体质较差、年龄大的老年患者,该术式是延长预期寿命的最佳手术方式。     

VEGF-A and Semaphorin3A: Modulators of vascular sympathetic innervation

Sympathetic nerve activity regulates blood pressure by altering peripheral vascular resistance. Variations in vascular sympathetic innervation suggest that vascular-derived cues promote selective innervation of particular vessels during development. As axons extend towards peripheral targets, they migrate along arterial networks following gradients of guidance cues. Collective ratios of these gradients may determine whether axons grow towards and innervate vessels or continue past non-innervated vessels towards peripheral targets. Utilizing directed neurite outgrowth in a three-dimensional (3D) co-culture, we observed increased axon growth from superior cervical ganglion explants (SCG) towards innervated compared to non-innervated vessels, mediated in part by vascular endothelial growth factor (VEGF-A) and Semaphorin3A (Sema3A) which both signal via neuropilin-1 (Nrp1). Exogenous VEGF-A, delivered by high-expressing VEGF-A-LacZ vessels or by rhVEGF-A/alginate spheres, increased sympathetic neurite outgrowth while exogenous rhSema3A/Fc decreased neurite outgrowth. VEGF-A expression is similar between the innervated and non-innervated vessels examined. Sema3A expression is higher in non-innervated vessels. Spatial gradients of Sema3A and VEGF-A may promote differential Nrp1 binding. Vessels expressing high levels of Sema3A favor Nrp1-PlexinA1 signaling, producing chemorepulsive cues limiting sympathetic neurite outgrowth and vascular innervation; while low Sema3A expressing vessels favor Nrp1-VEGFR2 signaling providing chemoattractive cues for sympathetic neurite outgrowth and vascular innervation.