Arthroscopic assessment of total hip replacement and polyethylene wear: a case report

We report the case of a patient who showed clinical and radiological signs of massive polyethylene wear 3 years after total hip replacement. Arthroscopy was performed to assess the loosening of the acetabular cup. The procedure showed the polyethylene element to be broken into three pieces in the area corresponding to the upper border. Received: 18 December 1998 Accepted: 25 November 1999     

Effects of total hip arthroplasty for primary hip osteoarthritis on postural balance: A systematic review

BackgroundHip osteoarthritis is one of the major causes of disability worldwide, and although total hip arthroplasty is considered effective in the management of this condition, its effects on postural balance remain unclear.Research QuestionWhat are the effects of total hip arthroplasty for primary hip osteoarthritis on the postural balance compared to preoperative status and/or to healthy controls?.MethodA systematic review was conducted, and the Embase, Latin American and Caribbean Health Sciences (LILACS), PubMed, Scopus, The Cochrane Library, and Web of Science databases were searched. Randomized and non-randomized studies were considered eligible for inclusion. The risk of bias of included studies was assessed using the Joanna Briggs Institute critical appraisal tools.ResultsAmong the 41 potentially eligible studies, 13 studies were included for qualitative synthesis—8 studies had low risk of bias and 5 had moderate risk of bias. Ten studies compared the effects of total hip arthroplasty on the postural balance in healthy controls. Meanwhile, the remaining 3 studies compared such effects to the preoperative status only. Comparable results on the postural balance between the intervention and control groups were observed in 5 studies, whereas 3 studies showed better scores among healthy controls. The other 2 studies reported that postural balance could still be impaired at 6 months to 3 years postoperatively. All 3 studies with no healthy controls reported an improvement in the postural balance compared to the preoperative status.ConclusionsMajor post-surgical improvements were consistently observed compared to preoperative status, although postural balance impairment was still noted compared to healthy controls.SignificanceThe results of this study might be a useful guide for clinicians on the extent of the therapeutic effects of hip arthroplasty on postural balance. Furthermore, the standardization of balance assessment tools could strengthen the certainty of cumulative evidence in future studies.     

三维CT全髋关节置换术后远期临床效果评价

目的利用三维CT技术评价全髋关节置换术后远期临床效果。方法选取18例全髋关节置换术患者,跟踪随访2～4年,通过三维CT影像技术,对人工假体磨损、移位及周围骨溶解情况进行分析。结果 18例全髋关节置换术患者术后2年假体功能良好(Harris评分85.4),髋臼杯移位程度较小,磨损情况较轻(0.17±0.05)mm。结论三维CT技术与传统X线方法相比精密度高、重现性好,适用于全髋关节置换术术前及远期临床效果的评价。     

Severe osteolysis and soft tissue mass around total hip arthroplasty: description of four cases and review of the literature with respect to clinico-radiographic and pathologic differential diagnosis

Periprosthetic osteolysis is a well known phenomenon caused by wear particle-induced bone resorption, particularly common and extensively reported in total hip arthroplasty. Its typical radiographic feature is a radiolucent area adjacent to an implant, sometimes associated with a soft tissue mass. Osteolytic changes may be caused by numerous other pathologic processes, including infection, metabolic disease, and neoplasia. Four cases of massive periprosthetic bone destruction associated with a large soft tissue mass around a failed total hip replacement are presented. In three cases, a diagnosis of periprosthetic osteolysis was correctly made and managed by revision surgery. However, in one case angiosarcoma of the ipsilateral hemipelvis went long unrecognized despite aggressive clinical course, requiring hind-quarter amputation and ultimately resulting in the patient's death. Periprosthetic malignancy in the form of either primary sarcoma or metastatic cancer is a very rare yet reported event in the setting of previous hip replacement, likely leading to catastrophic consequences when diagnosis is not established in a timely manner. The differential diagnosis of periprosthetic osteolysis should consider the entire spectrum of conditions that can present with radiolucent changes. Thorough review of patient's history and course of symptoms, along with careful evaluation of standard roentgenograms should be always performed and possibly integrated with imaging modalities such as CT, MRI, and bone scintigraphy in order to increase diagnostic accuracy. If uncertainty remains, biopsy should always be considered to rule out malignancy.     

全髋关节置换术中髋臼假体定位的研究进展

目前全髋关节置换术已成为治疗终末期髋关节疾病的有效手段,由于髋臼侧结构的特殊性,髋臼杯位置的定位方法尚有争议。髋臼假体定位方法主要有根据术前、术中影像学资料定位,根据髋臼局部解剖特征和(或)结合机械设备定位等,本文就髋臼假体位置定位的研究进展作一综述。     

Similar patient positioning: A key factor in follow-up studies when using model-based radiostereometric analysis of the hip

IntroductionDespite protocols, patients are not positioned exactly alike at radiostereometric (RSA) follow-up examinations, and it is unknown how much variation is tolerable. We report precision for optimal and extreme position differences from a phantom hip-study, and clinical precision of hip-RSA.MethodsA femoral stem with 3 bead-towers was fixed in a saw bone with bone-markers (phantom), and series of RSA examinations within optimal (5 × 5 cm and 5°) and extreme (20 × 30 cm and 30°) phantom positions were obtained. Double-examination RSA of 12 patients with the same femoral stem type were analyzed. Both model-based (CAD) and marker-based (MM) analysis was used. Precision was reported as standard deviation of differences.ResultsPrecision for translations in the optimal and extreme phantom position were below 0.06 mm and 0.02 mm for MM analysis, and below 0.05 mm and 0.18 mm for CAD analysis, respectively. Precision for rotations in the optimal and extreme phantom rotation were below 0.18° and 0.26° for MM analysis, and below 0.34° and 0.52° for CAD analysis, respectively. Clinical precision was 0.29 mm and 0.44° for MM analysis, and 0.40 mm and 1.59° for CAD analysis.ConclusionExtreme differences in patient position during RSA examination negatively affects precision, and CAD model-analysis was more sensitive than MM analysis. Longitudinal translation and rotation about the long stem-axis are the effect parameters which are most affected by position and rotation changes, and also the best indicators of implant loosening.Implications for practiceBased on our research, we recommend that similar patient positioning between follow-up RSA examinations is debated and prioritized.     

股骨偏心距对老年全髋关节置换术中应力水平影响的三维有限元分析

目的 利用三维有限元分析法评估老年患者不同股骨偏心距( femoral offset,FO)对骨水泥全髋关节置换术(total hip arthroplasty,THA)中应力水平的影响. 方法 对2例正常双髋关节用CT图像进行影像学测定,参数包括FO、颈干角和颈长.建立三维有限元模型,对THA中不同颈长、颈干角和FO的变化进行Von Mises应力分析. 结果 假体和骨水泥上应力随着颈干角的增加而单调下降,颈长在35 ～44 mm范围内,假体和骨水泥上应力水平较低,超过这一范围应力水平单调上升. 结论 降低假体和骨水泥上的应力、提高股骨上的应力及增加髋关节活动范围与FO密切相关.重建FO有利于恢复外展肌力臂及正常髋关节的生物力学功能.     

dGEMRIC and subsequent T1 mapping of the hip at 1.5 Tesla: normative data on zonal and radial distribution in asymptomatic volunteers

Purpose:

To characterize the zonal distribution of three‐dimensional (3D) T1 mapping in the hip joint of asymptomatic adult volunteers.

Materials and Methods:

This study included 10 volunteers (3 males and 7 females with a mean age of 26.5 years; range, 24–31 years). MRI protocol included standard sequences for hip imaging and a dual‐flip‐angle 3D gradient‐echo (GRE) sequence with volumetric interpolated breathhold examination (VIBE) postcontrast administration. Seven radial cuts were created clockwise around the femoral neck by using multi‐planar reconstruction.

Results:

Analysis of the radial distribution revealed an increase of T1‐values toward the superior regions. T1‐values differed between the peripheral and central portions. The standard deviation (SD) ranged from 76.2 ms to 124.1 ms in the peripheral zone, and from 69.1 ms to 112.9 ms in the central zone. In both zones, SD was low in the superior regions compared with the anterior and posterior regions of the joint. Based on the high intra‐ (0.95) and interobserver (0.87) agreement, normative data from this study will prepare the foundation for further studies of dGEMRIC and T1 in the hip.

Conclusion:

We noted a radial T1 mapping pattern with higher values in the superior zone that was not statistically significant and a notable trend in zonal distribution between peripheral and central zones. These findings are critical while outlining future studies for detailed objective evaluation of zonal cartilage lesions due to varying pathologies. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.     

全凭静脉麻醉下预注右美托咪定对罗库溴铵起效时间和作用时间的影响

目的观察全凭静脉麻醉下预注右美托咪定对罗库溴铵起效时间和作用时间的影响。方法 选取50例美国麻醉学会（American Society of Anesthesiology,ASA)Ⅰ~Ⅱ级全身麻醉下行鼻内窥镜手术的患者为研究对象,随机分为右美托咪定组和对照组,每组25例。右美托咪定组于麻醉诱导前15 min开始静脉泵入右美托咪定10 μg/kg(10 min内泵注完毕),对照组同法输注等量09%氯化钠注射液。给予丙泊酚和舒芬太尼全麻诱导,全凭静脉输注丙泊酚及瑞芬太尼麻醉维持。分别记录两组患者麻醉诱导给药前后、气管插管前及插管后1、3、5 min的平均动脉压(mean arterial pressure,MAP),心率(heart rate,HR),脉搏氧饱和度(pulse oxygen saturation,SpO2)值。采用加速度法四个成串刺激（train of four stimulation,TOF）监测肌松,记录罗库溴铵的起效时间和25%、50%、75%、90%的恢复时间。结果右美托咪定组与对照组相比较罗库溴铵的起效时间缩短(P<005),两组25%、50%、75%、90%恢复时间的差异均无统计学意义（P>005）。结论麻醉诱导前预注右美托咪定可以缩短罗库溴铵的起效时间,但对罗库溴铵的作用时间没有影响。     

The crescent sign: dissociation of the polyethylene liner from a modular acetabular component in total hip arthroplasty

Objective To study whether there was a common pattern of clinical symptoms, signs and radiographic features for the dissociation of the polyethylene liner from an acetabular component and to postulate reasons for these features.Design and patients Retrospective study of notes and radiographs of cases of revision hip arthroplasty for polyethylene liner dissociation of the cementless Harris–Galante I porous-coated acetabular component (Zimmer Inc, Warsaw, IN) at the Avon Orthopaedic Centre, Bristol, UK and St. Marys Hospital, Bristol, UK between 1995 and 2004. Patients were contacted to confirm preoperative symptoms.Results Nine cases of late polyethylene liner dissociation of this prosthesis have been revised in these institutions. All patients presented with a reduction in mobility, groin pain and limp. Eight patients reported an audible noise on hip movement. In all cases, radiographs showed radiolucency medial to the femoral neck in association with an eccentrically placed femoral head showing contact with the acetabular metal shell, which we have termed the crescent sign.Conclusions There is a typical clinical presentation in this study. The diagnosis can be made from a single anteroposterior pelvic radiograph without the need for previous films for comparison, or the need for arthrography. Clinicians should look specifically for the crescent sign when an eccentrically placed femoral head has been noted, in order to differentiate the more unusual diagnosis of dissociation from that of polyethylene wear. Early revision surgery can prevent damage to the femoral head and metal acetabular shell, thus reducing the complexity of revision surgery.     

Rehabilitation of gait in patients after total hip arthroplasty: Comparison of the minimal invasive Yale 2-incision technique and the conventional lateral approach

The minimal invasive anterolateral Yale 2-incision approach for total hip arthroplasty aims minimizing damage to the muscles for faster recovery of function. Therefore the hypothesis was investigated, that during the rehabilitation process the Yale approach shows a faster return to natural gait than a conventional lateral approach.Nineteen patients had the Yale, 16 the conventional Bauer approach. Instrumented gait analysis was performed 3 days, 3 and 12 month post operatively. Velocity, cadence, step length, weight bearing, thorax lean, Trendelenburg limp, hip abduction moments, and hip muscle activation times were evaluated.Three days post-surgery a significantly greater loading of the treated limb and increased hip abduction moment were observed in the Yale group. In addition, the Yale group showed its greatest improvement in walking speed and step length between at 3 days and 3 months, whereas the conventional group showed an additional significant gain between 3 and 12 month to reach a similar walking speed as the Yale group. For all hip muscles investigated, only muscle tensor fasciae latae in the conventional group showed a significant increase in activation time between 3 days and 3 months.This study showed significantly faster return to natural gait in the Yale compared to the conventional approach, which could be biomechanically related to less impairment of abductor muscles in the Yale approach.     

Initial results on development and application of statistical atlas of femoral cartilage in osteoarthritis to determine sex differences in structure: data from the Osteoarthritis Initiative

Purpose:

To create an average atlas of knee femoral cartilage morphology, to apply the atlas for quantitative assessment of osteoarthritis (OA), and to study localized sex differences.

Materials and Methods:

High‐resolution 3D magnetic resonance imaging (MRI) data of the knee cartilage collected at 3 T as part of the Osteoarthritis Initiative (OAI) were used. An atlas was created based on images from 30 male Caucasian high‐risk subjects with no symptomatic OA at baseline. A female cohort of age‐ and disease‐matched Caucasian subjects was also selected from the OAI database. The Jacobian determinant was calculated from the deformation vector fields that nonlinearly registered each subject to the atlas. Statistical analysis based on the general linear model was used to test for regions of significant differences in the Jacobian values between the two cohorts.

Results:

The average Jacobian was larger in women (1.2 ± 0.078) than in men (1.08 ± 0.097), showing that after global scaling to the male template, the female cartilage was thicker in most regions. Regions showing significant structural differences include the medial weight bearing region, the trochlear (femoral) side of the patellofemoral compartment, and the lateral posterior condyle.

Conclusion:

Sex‐based differences in cartilage structure were localized using tensor based morphometry in a cohort of high‐risk subjects. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.