CR-lipped bearing is an adequate functional solution to patients with perioperative excessive laxity in cruciate retaining total knee arthroplasty

BackgroundThe cruciate retaining lipped (CR-lipped) bearing is designed to provide more anterior-posterior (AP) stability and could be employed to resolve excessive intraoperative laxity during the cruciate retaining TKA (CR-TKA). The aim of the study was to determine whether the CR-lipped bearing in CR-TKAs with a perioperative excessive laxity allows equivalent functional results as compared to the standard CR articulation.MethodsA cohort of 111 TKAs with CR-lipped bearings was matched to a cohort of conventional CR bearings regarding age and sex. The CR-lipped bearing was used in patients with excessive knee AP laxity and the regular CR bearing was used in patients without excessive AP laxity during TKA. Various PROMs (WOMAC, KSS, SF-36) were assessed preoperatively and at 5-years postoperative in combination with revision rate and Range of Motion (ROM).ResultsPROMs did not differ significantly between both groups 5-years postoperatively. Mean ROM (flexion) 5-years postoperatively was not significantly different. The implant survivorship was 100% for both cohorts with revision for any reason as end point.ConclusionBased on these results, the CR-lipped bearing is a safe and effective solution for mild interoperatively assessed PCL laxity during CR-TKA without loss of function or decreased survivorship at 5 years. Peroperative conversion to a PS-TKA in order to obtain satisfactory functional scores might therefore not be necessary when mild PCL laxity is observed during surgery. Further research should focus on verifying this approach and longer follow-up is needed to generate data on long term survivorship.Level of evidenceLevel IV therapeutic, retrospective, cohort study.     

股骨胫骨髌骨三体人膝关节咬合运动数学模型

基于人膝关节的解剖特征，在文献［３］的基础上，引入了股骨髌骨关节，从而建立了一个完整的人膝关节在矢状面内运动的咬合数学模型。该模型包含了运动膝关节股骨与胫骨间及股骨与髌骨间的咬合滚动和咬合滑动。此模型可用来建立人腿的生物动力模型     

个性化截骨工具辅助下人工全膝关节置换与传统人工全膝关节置换手术精确度及临床疗效比较

目的比较3D打印个性化截骨工具辅助(patient-specific instrumentation,PSI)下人工全膝关节置换术(total knee arthroplasty,TKA)与传统TKA的手术精确度和临床疗效。方法自2017年9月至2018年12月,将40例拟接受初次膝关节置换患者随机分为2组,每组均为20人。一组应用个性化截骨工具辅助TKA手术(PSI组),另一组接受传统TKA(对照组)。比较两组患者的冠状面下肢机械轴线、手术时间、术中出血量、术后引流量以及HSS评分。结果对照组和PSI组的手术时间分别为(103.3±18.7) min和(91.3±15.7) min;术中出血量分别为(372.0±53.0)mL和(332.8±47.0)mL;术后引流量分别为(378.8±97.2)mL和(315.0±89.0)mL。两组手术时间、术中出血量、术后引流量比较差异均有统计学意义(P0.05)。对照组和PSI组术后2周HSS评分分别为(89.3±2.8)分和(88.7±2.9)分,两组比较差异无统计学意义(P0.05)。对照组和PSI组术后全下肢力线差值分别为(1.9±1.1)°和(1.2±1.0)°,冠状面股骨假体角度(frontal femoral component angle,FFC)差值分别为(2.1±1.1)°和(1.1±0.9)°,两组比较差异有统计学意义(P0.05)。冠状面胫骨假体角度(frontal tibia component angle,FTC)差值分别为(1.3±0.8)°和(1.4±0.8)°,两组比较差异无统计学意义(P0.05)。结论PSI辅助TKA较传统TKA手术时间更短、术中出血量更少,并且术后冠状面全下肢力线及股骨力线的改善优于传统TKA手术。     

Repeatability of measuring knee flexion angles with wearable inertial sensors

Background

As assessment with inertial-measurement-units (IMUs) increases in research and in clinics, it is important to be aware of the repeatability of these sensors. The objectives of this experiment were to evaluate the measurement repeatability of IMU joint angles using a repeatable robot controller and an anthropomorphic leg phantom and to determine effects of joint speed and sensor positioning on the angles collected by these sensors. Comparisons to an electro-goniometer and three-dimensional (3D) motion capture cameras were also completed.

Loss of the SEDL gene product (Sedlin) causes X‐linked spondyloepiphyseal dysplasia tarda: Identification of a molecular defect in a Japanese family

A 23‐year‐old man was diagnosed as having X‐linked spondyloepiphyseal dysplasia tarda (SEDT; MIM 313400) based on his disproportionately short trunk, short stature, characteristic radiological features of the spine (posterior hump, end plate sclerosis, and disc space narrowing) and the hips (short and thick femoral necks), and positive family history. This Japanese family was found to have an intragenic deletion flanking intron 2 and exon 3 of the SEDL gene that not only included the 5′ untranslated region but also the coding sequence for the first methionine through the 25th alanine. This mutation was present in the proband and his unaffected mother (a heterozygote), but not in an unaffected sister and an unaffected uncle. The nature of the mutation predicted that the SEDL protein (Sedlin) was not produced in the proband, indicating that loss of Sedlin caused SEDT. © 2001 Wiley‐Liss, Inc.     

Evaluation of human knee meniscus biopsies with near-infrared, reflectance confocal microscopy. A pilot study

Knee cartilage biopsy is used to confirm the pathology in both clinical and experimental conditions and often guides diagnosis and therapeutic strategies. Current histopathological techniques are time consuming, induce tissue artefacts and often prevent further evaluation, once the tissue has been fixed. Hence, there is a potential need for a fast and nondestructive imaging technique for unfixed tissue. Near-infrared, reflectance confocal microscopy (CM) allows real-time, virtual sectioning of unstained, bulk tissue samples. This pilot study evaluates the use of CM in the assessment of meniscus histopathology in a series of 26 freshly-excised human meniscus samples compared to standard light microscopy of stained sections. CM images of the meniscus show cell and matrix detail, depicting morphologic features of collagen and elastic fibres, vessels and nerve endings. In addition, crystal deposits of gout and pseudogout are also demonstrable. Thus, CM is a novel imaging technique that could enable the pathologist to make a rapid microscopic evaluation of cartilage in a fresh and unfixed fashion.     

Techniques of exposure for the stiff total knee

Primary and revision total knee arthroplasty have become common orthopaedic procedures. The operating surgeon, at times, may be faced with a difficult surgical case due to soft tissue contractures or bone deformities. A review of multiple surgical techniques using soft tissue releases and osteotomies are presented including their potential complications. Although these techniques are aimed at the atypical operative case, the operating surgeon may utilize them for ‘routine’ exposures as well. Importance is focused on the functional integrity of the knee extensor mechanism.     

Intrarater Reliability of Functional Performance Tests for Subjects With Patellofemoral Pain Syndrome

OBJECTIVE: Patellofemoral pain syndrome (PFPS) is a common clinical entity seen by the sports medicine specialist. The ultimate goal of rehabilitation is to return the patient to the highest functional level in the most efficient manner. Therefore, it is necessary to assess the progress of patients with PFPS using reliable functional performance tests. Our purpose was to evaluate the intrarater reliability of 5 functional performance tests in patients with PFPS. DESIGN AND SETTING: We used a test-retest reliability design in a clinic setting. SUBJECTS: Two groups of subjects were studied: those with PFPS (n = 29) and those with no known knee condition (n = 11). The PFPS group included 19 women and 10 men with a mean age of 27.6 +/- 5.3 years, height of 169.80 +/- 10.5 cm, and weight of 69.59 +/- 15.8 kg. The normal group included 7 women and 4 men with a mean age of 30.3 +/- 5.2 years, height of 169.55 +/- 9.9 cm, and weight 69.42 +/- 14.6 kg. MEASUREMENTS: The reliability of 5 functional performance tests (anteromedial lunge, step-down, single-leg press, bilateral squat, balance and reach) was assessed in 15 subjects with PFPS. Secondly, the relationship of the 5 functional tests to pain was assessed in 29 PFPS subjects using Pearson product moment correlations. The limb symmetry index (LSI) was calculated in the 29 PFPS subjects and compared with the group of 11 normal subjects. RESULTS: The 5 functional tests proved to have fair to high intrarater reliability. Intrarater reliability coefficients (ICC 3,1) ranged from.79 to.94. For the PFPS subjects, a statistical difference existed between limbs for the anteromedial lunge, step-down, single-leg press, and balance and reach. All functional tests correlated significantly with pain except for the bilateral squat; values ranged from.39 to.73. The average LSI for the PFPS group was 85%, while the average LSI for the normal subjects was 97%. CONCLUSIONS: The 5 functional tests proved to have good intrarater reliability and were related to changes in pain. Future research is needed to examine interrater reliability, validity, and sensitivity of these clinical tests.     

人体膝关节平地行走时的动力学模拟

基于美国BRG公司的运动及动力学仿真分析软件LifeMOD,建立包括股骨、胫骨、腓骨、4条主要韧带及肌肉在内的较完整的膝关节动力学模型,并用该模型模拟了人体下肢在平地行走时膝关节的动力学行为以及前交叉韧带缺损对膝关节接触力大小的影响。通过动力学分析,得到人体在平地行走时,胫股关节之间最大的接触力值为2645N,最大韧带张力为590N,发生在内侧副韧带上;当胫股关节之间的滑动受到限制时,最大的韧带张力发生在前交叉韧带上,为560N,研究结果与文献较接近。通过动力学模拟,可以得出结论：胫股关节之间的滑动对韧带张力有较大影响;前交叉韧带缺损使得胫股关节之间的接触力变小。     

全膝关节置换术的康复治疗及护理

目的 探讨人工全膝关节置换术后的康复训练方法。方法 回顾分析2001年8月至2005年8月16例（17膝）人工全膝关节置换术后病人康复训练的过程及效果。结果 人工全膝关节置换术后经过系统康复训练，所有膝关节功能评分达到（70-86分）平均80分。结论 人工全膝关节置换手术效果与术后全面系统的康复训练密切相关。