Comparison of three knee braces in the treatment of medial knee osteoarthritis

BackgroundConservative orthotic treatments rely on different mechanisms, such as three-point bending systems or hinges forcing external rotation of the leg and knee stabilization, to alter the biomechanics of the lower limbs and thus reduce knee loading on the affected compartment in patients with knee osteoarthritis (KOA). No previous study had compared the effects of these mechanisms on external loading and leg kinematics in patients with KOA.MethodsTwenty-four patients with medial KOA (Kellgren–Lawrence grade II or III) wore three custom knee braces: a valgus brace with a three-point bending system (V3P-brace), an unloader brace with valgus and external rotation functions (VER-brace) and a functional knee brace used in ligament injuries (ACL-brace). Pain relief, comfort, lower extremity kinematics and kinetics during walking were compared with and without each knee brace.ResultsKnee pain was alleviated with all three braces (p < 0.01). The VER- and ACL-braces allowed a significant reduction in peak knee adduction moment (KAM) during terminal stance from 0.313 to 0.280 Nm/Bw1Ht (p < 0.001) and 0.293 to 0.268 (p < 0.05), respectively, while no significant reduction was observed with the V3P-brace (p = 0.52). Reduced knee adduction and lower ankle and knee external rotation were observed with the V3P-brace but not with the VER-brace. The ACL-brace did not modify lower limb kinematics.ConclusionsNo difference between the knee braces was found for pain reduction, discomfort or KAM. The VER-brace was slightly more comfortable, which could ensure better compliance with treatment over the long term.     

Predicting dynamic knee joint load with clinical measures in people with medial knee osteoarthritis

Knee joint loading, as measured by the knee adduction moment (KAM), has been implicated in the pathogenesis of knee osteoarthritis (OA). Given that the KAM can only currently be accurately measured in the laboratory setting with sophisticated and expensive equipment, its utility in the clinical setting is limited. This study aimed to determine the ability of a combination of four clinical measures to predict KAM values.Three-dimensional motion analysis was used to calculate the peak KAM at a self-selected walking speed in 47 consecutive individuals with medial compartment knee OA and varus malalignment. Clinical predictors included: body mass; tibial angle measured using an inclinometer; walking speed; and visually observed trunk lean toward the affected limb during the stance phase of walking. Multiple linear regression was performed to predict KAM magnitudes using the four clinical measures. A regression model including body mass (41% explained variance), tibial angle (17% explained variance), and walking speed (9% explained variance) explained a total of 67% of variance in the peak KAM.Our study demonstrates that a set of measures easily obtained in the clinical setting (body mass, tibial alignment, and walking speed) can help predict the KAM in people with medial knee OA. Identifying those patients who are more likely to experience high medial knee loads could assist clinicians in deciding whether load-modifying interventions may be appropriate for patients, whilst repeated assessment of joint load could provide a mechanism to monitor disease progression or success of treatment.     

Provoked anterior knee pain in medial osteoarthritis of the knee

The incidence and the causes of provoked anterior knee pain in medial osteoarthritis (OA) of the knee were investigated clinically and radiographically. A retrospective study was performed in 179 primary osteoarthritic knees of 129 patients. Provocative tests were conducted on the patellofemoral (PF) joint to induce retropatellar crepitation, grating pain, tenderness around the patella, and pain on deviating the patella. The femorotibial angle (FTA) was measured on standing anteroposterior radiographs as a parameter of limb alignment. The widths of the medial and lateral joint space of the PF joint were measured on skyline views of standing or 30, 60 or 90° knee flexion. The angle of flexion contracture was measured on lateral radiographs of knees with maximum extension. The lateral shift and tilt of the patella were measured on standing skyline views. Retropatellar crepitation was found in 70% of knees, while provoked anterior knee pain was observed in 35–45% of knees with medial OA of the knee. Standing FTA was significantly greater in knees with tenderness around the patella and pain on deviating the patella than in those without these symptoms (P<0.05). The angle of flexion contracture was significantly greater in knees with provoked symptoms in the PF joint than in those without symptoms (P<0.05). The degree of lateral shift was greater in knees with provoked symptoms (P<0.05). Flexion contracture and varus deformity of the knee with lateralization of the patella may be factors aggravating provoked PF symptoms in medial OA of the knee. The radiographic assessment in this series failed to show a significant relationship between the width of the PF joint space and the incidence of provoked PF symptoms.     

Effect of walking with a modified gait on activation patterns of the knee spanning muscles in people with medial knee osteoarthritis

ObjectiveTo evaluate muscle activation patterns and co-contraction around the knee in response to walking with modified gait patterns in patients with medial compartment knee-osteoarthritis (KOA).Design40 medial KOA patients walked on an instrumented treadmill. Surface EMG activity from seven knee-spanning muscles (gastrocnemius, hamstrings, quadriceps), kinematics, and ground reaction forces were recorded. Patients received real-time visual feedback on target kinematics to modify their gait pattern towards three different gait modifications: Toe-in, Wider steps, Medial Thrust. The individualized feedback aimed to reduce their first peak knee adduction moment (KAM) by ≥ 10%. Changes in muscle activations and medial/lateral co-contraction index during the loading response phase (10–35% of the gait cycle) were evaluated, for the steps in which ≥ 10% KAM reduction was achieved.ResultsData from 30 patients were included in the analyses; i.e. all who could successfully reduce their KAM in a sufficient number of steps by ≥ 10%. When walking with ≥ 10% KAM reduction, Medial Thrust gait (KAM − 31%) showed increased flexor activation (24%), co-contraction (17%) and knee flexion moment (35%). Isolated wider-step gait also reduced the KAM (− 26%), but to a smaller extent, but without increasing muscle activation amplitudes and co-contraction. Toe-in gait showed the greatest reduction in the KAM (− 35%), but was accompanied by an increased flexor activation of 42% and hence an increased co-contraction index.ConclusionGait modifications that are most effective in reducing the KAM also yield an increase in co-contraction, thereby compromising at least part of the effects on net knee load.     

活动平台单髁置换修复膝关节内侧间室骨关节炎：4-6年随访

BACKGROUND: Unicompartment knee replacement is more popular for small trauma, rapid recovery, low complication and almost normal knee mechanics, and has been more and more used in clinic to repair single compartment knee disease. At present, there is no report about the influence of the angle of the single condyle prosthesis on the survival rate.     

活动与固定平台单髁置换治疗膝关节内侧单间室骨关节炎的随访

文题释义：单髁假体置换：为人工膝关节置换的一个特殊类型,是一种置换范围局限在单侧髁的置换。膝单髁关节置换与全膝关节置换几乎同时起步于20世纪70年代初期,单髁关节置换的目的是尽可能地保留正常的关节结构,以期获得更好的功能恢复,目前临床上单髁假体有活动平台和固定平台两种单髁假体。下肢机械轴位置Kennedy和White分布：把胫骨平台分为0、1、2、C、3、4、5几个区域,观察股骨头中心—踝关节中心连线经过胫骨平台的区域。KENNEDY和WHITE的研究发现,单髁置换后下肢机械轴经过2、C区的术后效果好,并发症少。背景：单髁置换假体主要分为活动平台和固定平台2种类型,由于两种平台假体的设计理念和手术操作方法上的不同,对于两种平台假体的选择还有一定分歧和争议。 目的：比较活动与固定平台单髁假体置换治疗膝关节内侧间室骨性关节炎的临床效果。 方法：选择2014年2月至2015年2月佛山市中医院收治的单侧膝关节内侧间室骨关节炎患者154例,男54例,女100例,年龄56-81岁,其中100例接受活动平台单髁假体置换治疗(活动平台组),54例接受固定平台单髁假体置换治疗(固定平台组)。记录并发症发生情况。术后随访膝关节目测类比评分、膝关节活动度、膝关节功能与临床KSS评分,复查X射线片(胫股角、髋-膝-踝角度、胫骨后倾角)评估下肢力线矫正情况。研究符合佛山市中医院对研究的相关伦理要求(fsz20130642)。结果与结论：①154例患者术后获得60-72个月的随访;②两组末次随访的膝关节目测类比评分、膝关节活动度、膝关节功能与临床KSS评分均较术前明显改善(P < 0.05),两组间比较差异无显著性意义(P > 0.05);③两组末次随访的胫股角、髋-膝-踝角度、胫骨后倾角均较术前明显改善(P < 0.05),活动平台组胫股角与髋-膝-踝角度的矫正值大于固定平台组(P < 0.05),两组间胫骨后倾角矫正值比较差异无显著性意义(P > 0.05);两组间下肢机械轴位置Kennedy和White分布比较差异无显著性意义(P > 0.05);④活动平台组出现1例假体松动,2例衬垫脱位;⑤结果表明,两种平台单髁置换假体治疗膝关节内侧间室骨性关节炎的中期随访临床结果无明显差异,但活动平台单髁假体置换下肢力线矫正角度较固定平台大,对于恢复下肢解剖轴线更有优势;2种单髁假体术后并发症发生率均较低,活动平台单髁置换后中期随访并发症发生率高于固定平台,活动平台中期并发症主要是假体松动、衬垫脱位。ORCID: 0000-0001-9062-8026(刘少华) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Dynamic alignment and its association with knee adduction moment in medial knee osteoarthritis

Lower limb dynamic alignment represents the limb position during functional loading conditions and obtains valuable information throughout the gait cycle rather than a single instant in time. This study aims to determine whether dynamic alignment is altered in medial knee osteoarthritis (OA) and how dynamic alignment is related to knee adduction moment (KAM). Community-dwelling women (n = 17) with medial OA in at least one knee, according to the American College of Rheumatology criteria and 17 body mass index-matched women without OA were recruited. A three-dimensional motion analysis system was used to collect the gait data at self-selected habitual and maximal speeds. Clinical evaluation of lower extremities, physical function, pain, habitual level of physical activity, quality of life and physical self-efficacy were assessed. Shank adduction angle and shank mean angular velocity were significantly greater in the OA group compared to the controls from heel strike to 30% stance. KAM was not different between the groups (p = 0.542). Dynamic alignment variables were the best predictors of KAM. Health-related quality of life, habitual level of physical activity, lower extremity muscle strength and balance performance were impaired in the OA group compared to the controls. The importance of variables that contribute to dynamic alignment and the contribution of limb alignment to KAM were highlighted in this study. Detection of postural changes such as altered dynamic alignment in early stages of OA will lead to the institution of joint-protective measures including changes in footwear, orthotics, gait re-training, use of assistive devices to reduce weight-bearing loads, strengthening and balance enhancing exercises, better analgesia, or cartilage-preserving pharmacotherapy.     

人工单髁关节置换治疗膝内侧间室骨性关节炎临床疗效分析

目的 探讨人工单髁关节置换(UKA)在膝内侧间室骨性关节炎治疗中的适应证选择、临床疗效及假体生存率。方法 回顾性分析2007年4月至2017年4月应用UKA治疗膝内侧间室骨性关节炎共500例患者的随访结果。其中,男176例,女324例;年龄43～91岁,平均61.12岁。根据年龄分组:中龄组133例,老龄组295例,高龄组72例。根据Iwano髌股关节影像学分级分组:0-1级组104例,2级组179例,3级组182例,4级组35例。通过膝关节活动度(ROM)、KSS评分与OKS评分评估临床疗效,记录术后并发症的发生率。采用Kaplan-Meier生存分析对单髁关节假体生存率、不同年龄与髌股关节退变程度对假体生存率的影响进行评估。结果500例患者均获得随访,末次随访时间2018年11月,共随访1.59～11.60年,平均5.27年。膝关节ROM:术前111°,术后117°(=-2.334,0.05); KSS评分:术前59分,术后93分(=-2.586,0.05); OKS评分:术前24分,术后45分(=-2.056,0.05)500例患者中共有20例术后并发症发生,人工单髁关节10年假体生存率为96.0%。年龄分组:中龄组10年假体生存率为89.8%,老龄组为99.0%,高龄组为97.2%,三组整体比较,差异有统计学意义(=12.37,=0.02);对于术后KSS及OKS评分而言,不同年龄组在整体比较以及组间比较并无明显差异,但老龄组术后膝关节活动度ROM显著高于高龄组患者,差异有统计学意义(=0.042)。Iwano影像学分级分组:0-1级组假体生存率为98.9%,2级组为92.7%,3级组为97.8%,4级组为96%,差异无统计学意义(=4.162,=0.244); Iwano各期患者术后ROM及KSS评分均未发现显著不同,4级组对术后OKS评分有显著降低,差异有统计学意义(=10.627,=0.00)。结论 UKA治疗膝内侧间室骨关节炎能够取得良好的临床疗效,传统单髁置换手术适应证可能已不再适应现代单髁置换手术,可通过准确的适应证选择以及精确的手术操作,以保证UKA获得良好效果,降低并发症发生率。     

Dynamic ultrasonography of the medial meniscus during walking in knee osteoarthritis

BackgroundMedial meniscal extrusion (MME) is a risk factor for the progression of knee osteoarthritis (OA). MME evaluation is crucial and it is commonly performed using magnetic resonance imaging (MRI) or static ultrasonography. We developed a prototype flat-shaped ultrasound transducer to visualize the actual meniscal movements during walking.ObjectiveThe aim of this study was to investigate whether it is feasible to visualize and evaluate the meniscal movements during walking using the novel flat-shaped ultrasound transducer for dynamic ultrasonography.MethodsSix participants who were diagnosed with primary unilateral or bilateral tibiofemoral knee OA on radiography (mean age, 67.1 ± 9.9 years; males/females, 4/2) and six healthy volunteers without any symptoms in their knees (mean age, 26.3 ± 4.0 years; males/females, 4/2) were enrolled in this study. The movement of the medial meniscus during walking was visualized using the novel transducer and the gait motion was recorded as video images that were synchronized with the ultrasonogram. MME and ΔMME (the difference between the minimum and maximum MME during the stance phase of the gait cycle) were evaluated in those with OA and compared with those in healthy volunteers.ResultsIn both groups, MME was visualized clearly in the stance phase. The mean values of MME and ΔMME in the knee OA group were significantly greater than those in the control group (P < .01).ConclusionsDynamic meniscal movement during gait can be evaluated with the specially developed novel ultrasound transducer. Our approach will be helpful in unveiling unknown pathological mechanisms in knee OA.     

膝骨关节炎患者膝关节置换后下肢肌的表面肌电图变化

背景：膝骨关节炎患者膝关节置换后下肢肌功能恢复一直存在着争议。 目的：评价膝骨关节炎患者膝关节置换手术后下肢肌肉功能。 方法：应用TELEMYO 2400R G2表面肌电图遥测仪对25例双膝骨关节炎单膝关节置换后患者在平常自然步态下进行双下肢股直肌、胫前肌、股二头肌和腓肠肌内侧的表面肌电信号测试。在肌电图测试前,对患者双膝关节功能进行美国特种外科医院膝关节评分。 结果与结论：患者置换后美国特种外科医院膝关节评置换侧平均分91.44,其优良率达100%;未置换侧平均分54.52。置换侧在疼痛、关节功能方面有明显改善;膝关节置换后置换侧股直肌、胫前肌、股二头肌的肌电振幅、肌电积分、平均频率、中位频率的(平均值、最小值、最大值)与未置换侧相比差异无显著性意义(P > 0.05);置换侧腓肠肌内侧肌电振幅值及肌电积分值显著大于未置换侧(P < 0.05);置换侧腓肠肌内侧平均频率、中位频率与未置换侧相比差异无显著性意义(P > 0.05)。提示膝关节置换后置换侧的下肢肌没有恢复到正常的功能活动水平,因此膝关节置换后康复要特别重视患者的肌肉锻炼。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

膝内侧骨关节炎患者膝关节功能与不稳定性的关系

背景：膝内侧骨关节炎患者身体缺陷与骨性关节炎发展的关系尚不清楚。 目的：调查膝内侧骨关节炎患者的身体功能和膝关节不稳定性,探讨二者间的关系。 方法：纳入诊断性膝内侧骨关节炎患者104例,采用膝关节日常生活活动评估量表衡量膝关节不稳,功能的自我评估采用膝伤和骨性关节炎结果评分,应用计时爬梯试验评估基于体能的身体功能,并进行放射影像学评估。 结果与结论：不同程度膝关节不稳患者的内侧松弛度、外侧松弛度、对线角度、标准化最大随意等长收缩及爬梯时间比较差异无显著性意义(P > 0.05)。但不同程度膝关节不稳患者在疼痛、症状、日常生活活动、运动和膝关节相关生活质量子集得分方面差异有显著性意义(P < 0.05)。在膝内侧骨关节炎患者中,自报膝关节不稳与内侧松弛度、股四头肌无力、内翻对线无直接联系。     

Up-regulation of CD44-positive cells in medial meniscus of medial compartmental osteoarthritis of the knee

The degeneration of medial meniscus in the medial compartmental osteoarthritic knee (OA knee) was investigated by the histological and immunohistochemical analysis. The series included 16 OA knees in 11 patients with mean age of 78.8±4.4 years (range, 73–86). The medial menisci were divided into the anterior, the middle and the posterior portion. They were subsequently stained with hematoxylin and eosin (H.E.) to evaluate the histological findings, and after that, immunohistochemical staining was performed and CD44-positive cells were counted. Tears of collagen fibers and degenerative changes of the medial meniscul structure were observed in all portions. The advancement of these degenerative changes was severer in the posterior portion than in the other and more remarkable as the osteoarthritis advanced. Immunohistochemical staining of the specimens revealed that CD44-positive cells concentrated around vessels and along tears adjacent to these vessels. In each grade (a radiographical grading system for OA knees — Koshino T, Machida J. Grading system of articular cartilage degeneration in osteoarthritis of the knee. Bull Hosp Jt Dis 1993;53:41–46), the mean number of CD44-positive cells in the middle and the posterior part was more than that in the anterior, especially in Grade 2 and 3 (P<0.05). In the medial compartmental OA knee, the advancement of degeneration in the meniscus was positively correlated with the advancement of the radiological grade, and the mechanical stress on the middle and the posterior part may up-regulate CD44 expression.     

佩带膝外翻支具膝骨关节炎患者膝关节的生物力学变化

背景：佩带膝关节外翻矫形器已被证明是一种可以有效减轻内侧间室膝骨关节炎患者疼痛的方法,但是佩带矫形器后的膝关节所产生的运动学以及动力学变化至今尚不明确。 目的：观察内侧间室膝骨关节炎患者佩带膝关节矫形器前后的膝关节运动学以及动力学参数变化,便于为将来设计新型膝关节矫形器提供依据。 方法：纳入20例内侧间室膝骨关节炎患者,分别通过三维步态分析系统和测力板对其在佩带膝外翻矫形器及不佩带膝外翻矫形器两种情况步行中的运动学及动力学参数进行采集,并进行对比。 结果与结论：相比未佩带膝关节外翻支具,佩带膝关节外翻支具后患者在步行过程中膝关节内收力矩明显减小,与此同时膝关节内翻角度明显减小,外翻角度明显增加(P均< 0.05),膝关节在步行过程中的最大屈曲角度以及时间空间参数差异无显著性意义。提示膝关节外翻矫形器可有效地通过增加内侧间室膝骨关节炎患者膝关节在步行过程中的外翻角度减小内翻角度从而降低膝内侧间室所承受的压力,与此同时纠正膝关节非正常对线。     

Relation between cartilage volume and meniscal contact in medial osteoarthritis of the knee

BackgroundThe purpose was to determine the relationship between the cartilage volumes in different regions of the femur and tibia, and the lengths of contacts between the meniscus and cartilage. The rationale was that less meniscal contact would make the cartilage more susceptible to loss of volume due to degeneration and wear.MethodsFifty MRI scans of osteoarthritic knees at varying degrees of severity were obtained. Computer models of the cartilage layers of the distal femur and proximal tibia were generated, from which cartilage volumes and thicknesses were calculated for different regions. The lengths of meniscal contact and heights were measured in frontal and sagittal views.ResultsCartilage loss progressed initially on the central and inner regions of the distal femur, and on the tibia in the region uncovered by the meniscus. As the cartilage volume decreased further, the wear spread medially, and to a lesser extent anteriorly and posteriorly. There were inverse relations between the loss of volume on both the femur and tibia, and the meniscal contacts and heights.ConclusionsCartilage loss initially occurred where there was direct contact between the cartilage of the femur and tibia. The meniscus did not prevent this, nor prevent the spread of the wear medially. This may have been due to the progressive reduction of cartilage-meniscal contact as the meniscus subluxed or lost substance, as the cartilage loss and deformity progressed. This suggested that the meniscus was not able to ameliorate the forces and pressures on the cartilage surfaces to prevent degeneration.     

膝骨性关节炎内侧半月板径向移位研究进展

膝关节骨性关节炎(OA)是骨科常见病，其发生机制至今尚未完全明了，国内外学者进行了多方面的研究，有关其病理变化多集中于关节软骨退变、骨质增生、滑膜炎等，而关于半月板径向移位的病理变化还未引起临床上足够重视。由于膝关节半月板在传导负载，提高关节接触面积方面具有重要作用，而各种不同原因所致膝关节载荷传导紊乱，可引起关节软骨退变及临近部位的软骨增生，所以膝半月板功能缺陷是罹患膝关节骨性关节炎的高危因素之一。有关半月板损伤、切除导致膝骨性关节炎等方面的研究颇多，而关于半月板径向移位的研究资料尚少，其与膝骨性关节炎发病机制的关系尚不清楚。     

膝骨关节炎模型内侧副韧带的生物力学特性

背景：膝骨关节炎多由力学和理化因素导致软骨基质退变而引起。目前对发病的理化因素和软骨基质的退变研究较多,力学研究较少。 目的：观察兔膝骨关节炎模型内侧副韧带拉伸力学性质的改变。 方法：左后肢伸直位石膏固定制动法建立兔模型。在Bose Electro Force 3300疲劳试验机上对正常对照组和模型组各6个试样进行拉伸实验。拉伸实验的速度为5 mm/min,计算机每0.1 s自动记录一个数据,直到将试样拉断。 结果与结论：正常对照组最大应力为(17.92±3.18) MPa,最大应变为(10.7±2.07)%,最大位移为(2.76±0.37) mm,弹性模量(316.19±74.55) MPa;模型组最大应力为(11.34±1.05) MPa,最大应变为(7.97±1.65)%,最大位移为(2.08±0.31) mm,弹性模量(279.77±33.91) MPa。正常对照组各项拉伸性能指标显著大于模型组(P < 0.05)。提示膝骨关节炎对膝关节韧带的生物力学特性具有一定影响。     

A quantitative assessment of varus thrust in patients with medial knee osteoarthritis

Varus thrust is an abnormal lateral knee motion frequently seen in patients with medial knee osteoarthritis (OA) during gait. It is a worsening of the alignment in the stance phase of the gait cycle and closely relates to disease progression. In this study, we measured the thrust quantitatively using skin markers and examined the relationship to other static and dynamic parameters. Forty-four knees in 32 patients (mean age, 72 years; range, 64–81 years) who exhibited the radiographic OA at least grade 2 according to the Kellgren–Lawrence (K–L) scale were enrolled. Gait analysis was performed for each patient to measure the amount of thrust and knee adduction moment. The amounts of thrust in subjects with K–L grades 2 (25 knees), 3 (13 knees), and 4 (6 knees) were 2.4°(± 1.3°), 2.8°(± 1.4°), and 7.2°(± 5.3°), respectively and the knee adduction moments were 3.6(± 1.5) %BW ? Ht, 3.9(± 1.2) %BW ? Ht and 6.9(± 2.2%) BW ? Ht, respectively. The amount of thrust also exhibited significant correlation to static radiographic alignment (R = 0.47: 95% confidence interval 0.67–0.21, p = 0.0038) and showed greater correlation to the knee adduction moment (R = 0.73: 95% confidence interval 0.84–0.55, p < 0.001), which has been identified as an important dynamic index of the disease. The amount of thrust, which is able to be measured by simple inexpensive equipment, correlated to static and dynamic parameters and may offer an important clinical index for knee OA.     

Instrumented gait analysis in patients with medial osteoarthritis of the knee after mobile-bearing unicompartmental knee arthroplasty

Background

Unicompartmental knee arthroplasty (UKA) is an effective treatment for patients with medial osteoarthritis of the knee joint. Instrumented gait analysis provides an objective measure to quantify and qualify postoperative changes of gait. The purpose of this study was to evaluate standardized instrumented gait analysis for functional recovery and gait as an outcome of mobile-bearing UKA in patients with medial osteoarthritis of the knee.

Effect of medial tibial torsion on the sagittal alignment of lower legs in patients with medial knee osteoarthritis

Purpose

The fibular axis (FA) and anterior tibial cortex (ATC) are good determinants of the sagittal mechanical axis (MA) of lower legs during total knee arthroplasty (TKA).When compared with healthy subjects, a significant medial tibial torsion has been reported in patients with medial knee osteoarthritis; this should affect the alignment of lower legs. The purpose of this study was to clarify the effect of the medial torsion on relationship between sagittal MA and intraoperative references (FA and ATC).

Methods

Fifty knees of 50 patients with medial knee osteoarthritis who underwent primary TKA were included in this study. Using preoperative computed tomographic data, the tibial torsion angle was measured in the axial plane. The angle between FA and MA, and the angle between ATC and MA were also measured in the sagittal plane.

Results

The tibial torsion angle was 7.9° ± 7.2° (range ?11.3° to ?24.3°). The angle between MA and FA was ?1.8° ± 0.8° (range ?0.1° to ?4.3°), and the angle between MA and ATC was 4.6° ± 0.5° (range 3.1° to 5.5°). The population variance was significantly larger for the angle between MA and FA than that between MA and ATC (P = 0.0160). There was a significant positive correlation between the tibial torsion angle and the angle between MA and FA (R ² = 0.5111, P < 0.0001).

Conclusion

The angle between FA and MA in the sagittal plane increased in patients with large medial tibial torsion.     

Isokinetic assessment of the hip muscles in patients with osteoarthritis of the knee

OBJECTIVES:

To evaluate the difference in isokinetic strength of hip muscles between patients with knee osteoarthritis (OA) and matched healthy controls, and to establish the correlation between this isokinetic strength and pain and function in patients with knee OA.

METHODS:

25 patients with a diagnosis of unilateral knee OA, 25 patients with bilateral knee OA, and 50 matched controls were evaluated using the visual analog scale for pain, knee Lequesne index, Western Ontario and McMaster Universities questionnaire and an isokinetic test.

RESULTS:

The groups were matched for age, gender and body mass index. The results of the isokinetic test revealed lower peak torque of the hip in patients with OA of the knee than in the control group for all movements studied. Strong correlations were found between the peak torque, visual analog scale and function.

CONCLUSIONS:

Patients with OA of the knee exhibit lower isokinetic strength in the hip muscles than healthy control subjects. Strengthening the muscles surrounding the hip joint may help to decrease pain in people with knee OA. Some correlations between pain/function and peak torque were found.