Feasibility,correlates, and validity of the one-leg sit-to-stand test in individuals following anterior cruciate ligament reconstruction

ObjectiveRegular quadriceps strength assessment is important following anterior cruciate ligament reconstruction (ACLR). The one-leg sit-to-stand (OLSTS) test potentially overcomes the barrier of accessibility to specialised testing equipment. However, feasibility and validity testing of OLSTS is lacking in the ACLR population. This study aims to examine the feasibility, correlates, and predictive validity of OLSTS with self-reported running and jumping difficulty in individuals post-ACLR.DesignRetrospective longitudinal study.Methods20 patients with primary unilateral ACLR were tested at 6-months and 1-year post-ACLR. Feasibility was assessed by the number of patients who had safely performed OLSTS at both timepoints. Cross-sectional gender-adjusted Spearman correlations of OLSTS with quadriceps strength, physical impairments, and psychological variables were measured at 6-months. Predictive validity was assessed via ordinal regression, quantifying the associations of OLSTS with self-reported running and jumping difficulty across time-points.ResultsAll patients understood the instructions to and were able to self-administer the OLSTS test safely. OLSTS is a valid measure of quadriceps strength (gender-adjusted Spearman's ρ = 0.53, P = 0.02). Knee pain (ρ = 0.44, P = 0.046) and readiness to return-to-sport (ρ = 0.55, P = 0.02) were additional correlates. Greater OLSTS performance was associated with greater odds of better self-reported running and jumping function (interquartile-range ORs, 12.0 [95% CI: 3.6–45] and 18.5 [95% CI: 5–67], respectively).ConclusionOLSTS is a feasible and valid test of quadriceps strength, demonstrating predictive validity with self-reported running and jumping post-ACLR. OLSTS potentially allows independent tracking of ACLR rehabilitation progress at home – an increasingly urgent necessity in the face of a global pandemic.     

Retro-odontoid pseudotumor without atlantoaxial subluxation

A retro-odontoid pseudotumor (ROP) is commonly associated with atlantoaxial subluxation (AAS). Here, we report a patient with ROP but without AAS. The patient was a 72-year-old man who did not have a history of rheumatoid arthritis or trauma to the head and neck. The patient was admitted to our hospital with gait disturbance, progressive motor weakness in both upper extremities and sensory disturbance in all four extremities. MRI showed a retro-odontoid mass with severe compression of the cervical spinal cord. A CT scan showed spondylotic changes in C5, C6, and C7 and bilateral facet fusion between C3 and C4. Dynamic radiography showed no evidence of AAS; there was loss of mobility at C2–C7 and excessive mobility at C1. Intraoperative pathological examination revealed that the lesion was a pseudotumor; therefore, posterior C1–C2 fixation was performed. MRI performed 6 months after the operation revealed that the pseudotumor was markedly reduced. To the best of our knowledge, patients with ROP without AAS are uncommon.     

Microstructures and mechanical properties of silks of silkworm and honeybee

Natural silks as important biomaterials have wide applications in scaffolds for tissues, biocompatible coatings and drug delivery, etc. In this paper, we report on the microstructures and mechanical properties of honeybee and silkworm silks. The microstructures and mechanical properties of these natural silks are measured by environment scanning electron microscopy (ESEM), scanning probe microscopy (SPM), tensile tests, and nanoindentation. It is found that the honeybee silk appears as a single fiber with a circular cross-section and has a much finer and smoother texture than the silkworm silk. The honeybee silk exhibits a distinct linear and brittle elastic feature with an elastic modulus of 6.5 GPa and a breaking strain of 3.8%, whereas the silkworm silk possesses a nonlinear and hierarchical failure character with an initial elastic modulus of 8.9 GPa and a breaking strain of 15.7%. Moreover, the nanoindentation measurements show that the honeybee silk exhibits much less anisotropy than the silkworm silk. The ratio of the longitudinal modulus to the transverse modulus of the honeybee silk is 2.0, whereas that of the silkworm silk is 18.9. The different structural and mechanical properties of the honeybee and silkworm silks are likely a result of their specific biological functions.     

Relationship Between Osteopenia and Lumbar Intervertebral Disc Degeneration in Ovariectomized Rats

Ovariectomy (OVX) can cause bone loss in rats, but little is known about how it also induces lumbar intervertebral disc degeneration (LVD). This study investigated how estrogen deficiency affected intervertebral discs in OVX rats. Thirty 3-month-old female Sprague–Dawley rats were divided randomly into three equal groups. The baseline control group (BL) was killed at the beginning of the experiment. An ovariectomy was performed in 10 rats (OVX group) and another group of 10 rats was subjected to a sham surgery (Sham group). The OVX rats were untreated after the surgery to allow for the development of moderate osteopenia. Bone mineral density (BMD) measurement and bone histomorphometric analysis were applied to the segments of lumbar spines in all rats killed 6 months after surgery. The pathological changes of intervertebral discs were observed and the degree of LVD was scored by a histological scoring system. The BMD of the spines (L3–L5) in the OVX group decreased significantly compared with the Sham group. The bone volume indices in the OVX group were significantly lower, but the bone turnover rate parameters were significantly higher than those in the Sham group (P < 0.01). The histological scores for LVD in the OVX group were significantly higher than those in the Sham group (P < 0.01). There was a significant negative correlation between the BMD and Grade II discs in the OVX rats (P = 0.042). In conclusion, LVD occurs in the OVX rats and the degeneration of cartilage end plates may be a pathogenic factor in disc degeneration.No benefits in any form have been or will be received from a commercial party related directly or indirectly to the support of this article. No funds were received in support of this study.     

Analysis of in-vivo articular cartilage contact surface of the knee during a step-up motion

BackgroundNumerous studies have reported on the tibiofemoral articular cartilage contact kinematics, however, no data has been reported on the articular cartilage geometry at the contact area. This study investigated the in-vivo tibiofemoral articular cartilage contact biomechanics during a dynamic step-up motion.MethodsTen healthy subjects were imaged using a validated magnetic resonance and dual fluoroscopic imaging technique during a step-up motion. Three-dimensional bone and cartilage models were constructed from the magnetic resonance images. The cartilage contact along the motion path was analyzed, including cartilage contact location and the cartilage surface geometry at the contact area.FindingsThe cartilage contact excursions were similar in anteroposterior and mediolateral directions in the medial and lateral compartments of the tibia plateau (P > 0.05). Both medial and lateral compartments were under convex (femur) to convex (tibia) contact in the sagittal plane, and under convex (femur) to concave (tibia) contact in the coronal plane. The medial tibial articular contact radius was larger than the lateral side in the sagittal plane along the motion path (P < 0.001).InterpretationsThese data revealed that both the medial and lateral compartments of the knee experienced convex (femur) to convex (tibia) contact in sagittal plane (or anteroposterior direction) during the dynamic step-up motion. These data could provide new insight into the in-vivo cartilage contact biomechanics research, and may provide guidelines for development of anatomical total knee arthroplasties that are aimed to reproduce normal knee joint kinematics.     

加速康复外科理念下跟骨关节内骨折诊疗规范专家共识

跟骨骨折是最常见的后足骨折,通过国内外医师学者的长期研究,其在诊治方面有了长足的进步。近年来,加速康复外科(ERAS)理念的引入,更加规范了跟骨骨折围手术期的处理流程,有助于提高治疗效果,改善患者治疗体验。本共识以ERAS理念为指导,以循证医学证据为基础,经全国创伤骨科专家讨论形成。本共识从多模式镇痛、术前宣教、围手术期饮食管理、手术微创操作等ERAS涉及的多个方面进行推荐,为治疗此类骨折提供参考。     

可吸收钉板在颈椎前路椎体次全切除术中的应用研究

[摘要] 目的 探讨颈前路椎体次全切手术应用Inion S-1?生物型可吸收钉板对比传统钛质钉板治疗颈椎病的疗效分析。方法2010年1月~2014年4月，收治患者33例行颈椎前路手术，其中A组12例，采用Inion S-1?生物型可吸收钉板固定，B组21例采用钛质钉板固定。比较两组患者术后1周、3个月、1年VAS疼痛评分、JOA评分、颈椎功能障碍指数（NDI），以及两种钉板对于影像成像的影响、相邻节段退变情况，植骨融合率，并发症。结果33例患者均获随访，随访时间10~25个月，平均16.2个月。A、B两组在术后1周、3个月、1年VAS疼痛评分、JOA评分和NDI评分比较差异无统计学意义（P>0.05）。两组椎体间均获得骨性融合，融合率100%。B组3例出现相邻节段退变。无内固定失效、失败、脱落、松动、折断等并发症，远期均无迟发型食道瘘出现。两组术后1年融合上位相邻节段活动度比较差异具有统计学意义。结论 颈前路椎体次全切术中应用Inion S-1?生物型可吸收钉板能取得和钛质钉板相同的近期疗效。可在一定程度上避免应用传统钛质钉板术后内植物松动、融合过程中的应力遮挡、影像干扰等常见缺点。     

Editorial Commentary: Not Yet Convinced That the Femoroacetabular Impingement Resection (Fair) Arc Measurement Provides a “Fair” Assessment of Cam Resection Principles

Hip arthroscopy has proven to be an effective surgical approach for the treatment of femoroacetabular impingement (FAI) syndrome. Studies have shown that patients typically have improved functional outcomes and high rates of return to activity following cam lesion resection and reshaping of the femoral head-neck junction. However, despite these favorable outcomes, there is still a steep and well-recognized learning curve in FAI hip arthroscopy. Although it is common dogma to consider an ideal reshaping of the femoral head-neck junction as being perfectly spherical, the ability to achieve this intraoperatively can be quite challenging. A new tool is the “femoroacetabular impingement resection (FAIR) arc,” measured on a 45° Dunn lateral radiograph where a best-fit circle incorporates the region immediately inferior to the anteroinferior iliac spine, the subspine region, and lateral femoral neck base. The maximal radial distance height is then measured from the circumference of this circle to the apex of the cam lesion. This radiographic aid may assist with intraoperative estimate of appropriate cam lesion resection depth. While I tend to utilize preoperative radiographs and intra-operative neck sclerosis to determine cam resection depth, I continue to seek out other ways to effectively perform a femoral osteoplasty. While my initial attempt to utilize the FAIR index in my practice did not seem effective, I will continue to test this measurement in my patients.