Knee kinematics in functional activities seven years after total knee arthroplasty

BACKGROUND: Detailed knowledge of knee kinematics during functional activities is lacking in current studies on the long-term outcome of total knee replacement surgery. The aim of this study was to assess functional knee kinematics using flexible electrogoniometry in patients seven years after unilateral primary total knee arthroplasty for osteoarthritis. METHODS: The knee joint functional movement of a cohort of patients (n=19) with knee osteoarthritis was assessed using electrogoniometry before surgery and 18-24 months and seven years after total knee surgery. The mean age of the patients (11 women and 8 men) at the time of the pre-surgery assessment was 67 years old (SD 8.0). Patient function was also assessed using the Knee Society Score and WOMAC osteoarthritis Index. FINDINGS: The function components of the Knee Society and WOMAC scores were significantly decreased at seven years compared to 18-24 months after surgery (both P<0.05). However, the majority of the functional knee flexion values derived from electrogoniometry did not decrease. Seven years after surgery, knee excursion during ascending and descending stairs was significantly improved compared to 18-24 months after surgery (both P<0.01). INTERPRETATION: The finding that functional knee motion continues to improve between 18-24 months and seven years post-surgery is of interest to both patients and those responsible for their treatment planning. Further, it was shown that the WOMAC and Knee Society Scores do not follow the same trends as the patients' functional knee kinematics seven years after total knee replacement surgery.     

Prehabilitation versus usual care before total knee arthroplasty: A case report comparing outcomes within the same individual

This case report compared pre- and postoperative functional ability, knee strength, and pain of a female who underwent two separate total knee arthroplasty (TKA) procedures. The female patient was part of a larger research study. The first surgery on the right knee was preceded with usual care and the second surgery on the left knee was preceded by prehabilitation. Functional ability was assessed by a 6-minute walk, chair raises, and the time required to ascend and descend stairs. Knee extension and flexion isokinetic strength was assessed using the KinCom Isokinetic Dynamometer. Pain was assessed using the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC). Functional abilities, knee strength, and pain were assessed at baseline measurements 4 weeks before surgery, 1 week before surgery, and at 1 and 3 months post surgery during each TKA procedure. Results indicate that the prehabilitation intervention had a favorable impact on improving functional ability up to 30%, increasing knee strength by 50% and decreasing pain prior to the left knee TKA. For this patient, prehabilitation increased functional ability and strength prior to surgery. Gains in strength were maintained in the nonsurgical knee after surgery. These findings indicate that prehabilitation may be effective at facilitating the rehabilitation following a TKA.     

Muscle strength in patients with unicompartmental arthroplasty

OBJECTIVE: The aim of the current study was to evaluate the isokinetic strength of the knee in patients with unicondylar prostheses, to compare these results with healthy control subjects of the same age, and to correlate these results with clinical scores. DESIGN: Seventeen patients were examined an average of 21.5 mos after surgery. Clinical examination was done using the Hospital for Special Surgery, Knee Society, and patellar scores and a visual analog scale for pain. Quality of life was assessed by the Short Form 36 Health Questionnaire. Isokinetic evaluation of knee extensor and flexor muscles was done using a Cybex 6000 dynamometer at angular velocities of 60 and 180 degrees/sec. Eleven healthy subjects of comparable age served as a control group. RESULTS: Clinical results differed significantly in all categories. Quality of life differed only in the items of physical functioning, role limitation because of physical problems, and bodily pain. Isokinetic strength in patients showed a loss of torque of approximately 30% in extension and flexion at 60 and 180 degrees/sec compared with the control group. The flexion and extension ratio and the angles of maximum torque did not differ between the groups. CONCLUSION: In comparison with healthy control subjects, persons with an implanted unilateral sledge prosthesis have strength deficits in extension and flexion. A deficit of the extensor muscles, as it has been described previously for patients with a total knee arthroplasty, could not be found.     

Effect of a functional knee brace on knee flexion and extension strength after anterior cruciate ligament reconstruction

OBJECTIVES: To investigate the effect of a knee brace on knee flexion and extension muscular strength of patients after anterior cruciate ligament (ACL) reconstruction and to evaluate whether the effect of the brace depends on patient symptoms and muscular strength. DESIGN: Repeated measures. SETTING: A university-based outpatient orthopedic clinic and musculoskeletal assessment laboratory. PARTICIPANTS: Twenty-seven patients (14 women, 13 men; mean age, 28+/-11 y) having undergone arthroscopically assisted ACL reconstruction by using a semitendinosus and gracilis autograft. INTERVENTION: A custom-fit ACL functional knee brace. MAIN OUTCOME MEASURES: The brace effect was calculated as the change in peak torque observed with the brace, expressed as a percentage of peak torque observed without the brace, during isokinetic concentric knee flexion and extension movements performed at 90 degrees /s. Patient symptoms were quantified by using a disease-specific health-related quality of life questionnaire. RESULTS: Knee flexion strength decreased significantly with the brace (mean brace effect=-7.3%, P<.05). The brace effect during knee flexion varied considerably (-52% to 47%) and was significantly related to peak torque observed without the brace (r=-.50, P<.01). All other comparisons and correlations were not significant. CONCLUSIONS: These findings suggest that brace effects depend on patient strength. A brace may inhibit knee flexion strength of stronger patients, yet result in no change or even improvements in strength of weaker patients. Future research is required to further elucidate which patients may derive most benefit or detriment from bracing.     

External rotation strength deficit after hip resurfacing surgery

Purpose: The aim was to assess the effect of resurfacing hip arthroplasty on hip muscle function, when, in the posterior approach, the piriformis tendon and outer rotators of the hip joint were divided. The unoperated side was used as a control.

Methods: Thirty-three consecutive patients (mean age 55 years, 73% males) were operated using the posterior approach. Main outcome measures were isometric muscle strength of external and internal rotators and extensors of the hip and hip pain.

Results: Hip external rotation strength (p > 0.001) and leg extension strength (p < 0.001) were significantly lower on the operated side compared with the un-operated side prior to the surgery. On the operated side external rotation strength decreased by 29% (p < 0001) and internal rotation strength increased by 28% (p < 0.001). The changes of 12% in leg extension strength of the operated side and the changes of 3–10% in all strength measurements in the un-operated side were not significant. Three months post-operatively, the external rotation strength and leg extension strength values were 50% and 26% lower (p < 0.001) on the operated side compared with those in the un-operated side. The decreases in pain values during the rest, loading as well as during the strain of strength measurements were all significant (p < 0.001).

Conclusion: Although hip resurfing surgery gives excellent relief of pain, significant strength deficit was found in the external rotators 3 months post-operatively.     

Isokinetic knee extensor strength deficit following matrix-induced autologous chondrocyte implantation

Background

Autologous chondrocyte implantation has become an established technique for addressing knee cartilage defects. Despite reported improvement in pain and regeneration of hyaline-like repair tissue, little has been reported on the recovery of knee strength.

Methods

Knee strength assessment was undertaken in 60 patients at 5 years following autologous chondrocyte implantation. Using an isokinetic dynamometer, and during isokinetic knee extension and flexion angular velocities of 60°, 90° and 120°/s, the peak torque, torque at 45° of knee flexion and hamstrings/quadriceps ratio was obtained, in both the operated and non-operated limbs. Pain at the time of assessment was obtained. Independent sample t-tests were used to assess differences in the operated and non-operated sides.

Findings

There were no significant differences (p > 0.05) between the operated and non-operated legs in the peak knee flexor torque or knee flexor torque at a knee flexion angle of 45°, at all angular velocities (60°, 90° and 120°/s). While the peak knee extensor torque was less in the operated leg at all angular velocities, these differences were not significant (p > 0.05). However, a significantly reduced (p < 0.05) knee extensor torque at a knee flexion angle of 45°, was observed at all speeds.

Interpretation

While patients had recovered their knee flexor strength, they still demonstrated a reduced knee extensor strength profile at 5 years. This demonstrates that the early supervised rehabilitation phase following autologous chondrocyte implantation is not sufficient to restore long-term knee strength, and ongoing patient advice and rehabilitation is required extending beyond this early period. It is unknown how this prolonged reduction in strength may affect long-term graft outcome.     

全膝关节置换术后关节活动范围的影响因素分析

目的:探讨全膝关节置换术后关节活动范围的影响因素,从而制订相应的康复治疗方案。方法:21例接受全膝关节置换术的患者入组,采用HSS评分法对所有患者进行术前膝关节功能评估,应用关节量角器对膝关节进行关节活动范围测定。采用Pearson相关分析法对术前各因素与术后1、2周及出院时膝关节活动范围进行相关分析。采用独立t检验对术后1、2周及出院时膝关节活动范围进行比较。结果:术前HSS总分、术前关节疼痛、术前膝关节功能、术前膝关节活动和术前屈膝畸形与术后1周膝关节活动范围成正相关,相关系数分别为0.546、0.430、0.423、0.539和0.403,P<0.05。术前所有评估因素除年龄外与术后2周和出院时关节活动度无相关。结论:术前关节疼痛、膝关节功能、膝关节活动和术前屈膝畸形与术后膝关节活动范围相关。     

Patients waiting for a hip or knee joint replacement: is there any prioritization for surgery?

Objective To investigate whether patients are prioritized for joint replacement surgery on the basis of severity of osteoarthritis, pain and physical functioning. Method A total of 105 patients on the waiting list for primary total knee or hip replacement from a UK regional orthopaedic centre were interviewed at baseline and followed up at 3, 6 and 9 months or until joint replacement. Measurement tools were the visual analogue scale (VAS), Western Ontario and McMaster Universities (WOMAC) osteoarthritis index and the Oxford hip or knee score. Results Most participants (81, 77%) were categorized on the waiting list as ‘routine’, despite having high levels of pain according to the measurement scales. There was no significant correlation between the waiting list categorization and the actual waiting time for a hip or knee joint replacement operation (Kendall’s tau = 0.17; P = 0.062) and the waiting list categorization did not appear to ensure that patients were operated upon earlier. There were also no significant differences in measures (VAS pain, WOMAC and Oxford hip or knee scores) between those individuals who had their operations earlier (before 6 months) compared with those participants who had their operations later (6 months or greater) or even not at all. Of the 105 patients who were listed for joint replacement, 24 (25%) patients did not have their operation due to: a medical delay (14); self‐delay/cancellation (7); arthroscopy instead (2); and death (1). Conclusion With the expected increase in demand for joint replacement, there needs to be a re‐examination of assessment procedures of patients listed for joint replacement. The use of measurement tools to assess symptoms such as pain and physical function would be one way forward.     

QWIX螺钉置入内固定修复髌骨骨折：骨折断端的持续动静态加压作用

背景：髌骨骨折造成最重要的影响是伸膝装置连续性的断裂及潜在髌股关节的不协调。髌骨骨折手术治疗的目的是恢复髌骨关节面的平整性、维持伸膝装置的连续性、提供稳定有效的固定以便早期进行功能锻练。目的：探讨QWIX螺钉结合克氏针、钢丝置入内固定修复髌骨骨折的临床效果。方法：2011年9月至2012年9月重庆医科大学附属第一医院采用QWIX螺钉结合克氏针、钢丝置入内固定修复髌骨骨折30例,男17例,女13例,平均年龄47.7岁。术中根据骨折的粉碎情况及移位程度分别采用QWIX螺钉或QWIX螺钉＋张力带钢丝或QWIX螺钉＋克氏针＋张力带钢丝的方式进行内固定,术后第1天允许患者进行膝关节主、被动屈伸锻炼,无附加外固定。术后6周、3个月、6个月、12个月、1年进行门诊随访,明确患者骨折愈合情况,有无并发症发生,测量双侧膝关节屈伸活动范围,术后1年应用Bostman评分对患侧膝关节功能进行评估。结果与结论：所有患者均获得随访,随访时间12-24个月。24例于术后3个月内愈合,6例于术后4个月内愈合,平均骨折愈合时间为3.2个月。随着时间的延长,患者膝关节屈伸范围不断增加,术后1年患者膝关节功能均恢复至伤前水平。随访期间1例患者因克氏针松动引起膝关节疼痛不适,其余患者无感染、膝关节疼痛、内固定失效、膝关节屈伸功能障碍等并发症发生。根据Bostman评分标准对术后1年时患者膝关节功能进行评估,优27例,良3例,差0例,优良率为100%。提示QWIX螺钉结合克氏针、钢丝置入内固定修复髌骨骨折具有骨折断端持续动静态加压、允许患者早期屈伸锻炼、减少内固定相关并发症等优点,是修复髌骨骨折的有效方法。     

Swelling of the upper extremity, function and muscle strength of shoulder joint following mastectomy combined with radiotherapy.

Swelling of the arm, mobility of the shoulder joint and muscle strength were examined in 76 patients with breast cancer 4.5 to 14 years (mean 8 years) after primary therapy. Marked arm swelling was found on the operated side in 31% of the patients operated by radical mastectomy and in 18% of those having undergone total mastectomy. The swelling was more marked in the upper arm than in the forearm. Patients irradiated postoperatively with a megavoltage technique showed more often and more oedema than those treated with a kilovoltage technique. Obese patients had more swelling than patients of normal weight. Of the various movements of the shoulder joint, abduction, adduction, flexion, extension, horizontal extension and internal rotation were significantly reduced on the operated side in comparison with the non-operated side, but the differences were not great. Neither swelling of the arm nor the patient's weight had any effect on the function of the shoulder joint, as expressed in terms of abduction. Of the muscle groups in the shoulder joint adductors, flexors and extensors were significantly weaker on the operated than on the non-operated side. The muscle strength of the operated side averaged 25% weaker than that of the control side. Swelling of the arm did not reduce the muscle strength of the shoulder joint.     

关节镜下膝前交叉韧带重建术后的康复

探讨安全有效的前交叉韧带重建术后康复。方法:膝关节前交叉韧带(ACL)重建(BPTB)患者60例,按照我中心现行康复程序进行功能锻炼。术后1年进行关节活动度、肢体围度测量及问卷调查。使用等张肌力测试系统对术后3个月后坚持练习和未坚持练习患者各10例,评定双侧腿肌力,比较各项参数。结果:全部患者术后3个月恢复全范围AROM、正常ADL及患膝屈肌肌力,6—7个月恢复正常运动,大部分专业运动员恢复原有竞技性运动水平。术后坚持练习组与未坚持练习组肌力比较,伸肌最大输出功率、最大收缩速率、最大力量存在显著差异(P<0.05),伸肌疲劳系数及屈肌力量无显著差异(P>0.05)。术后1年,大腿及小腿围度较健侧有显著差异(P<0.01,P<0.05)。结论:ACL重建术后康复治疗程序安全有效,患者短期(3个月)可恢复正常AROM、ADL及患腿屈肌肌力,并逐步恢复正常运动。膝伸肌肌力需坚持长期练习,才可更好恢复。     

Evaluating waiting time effect on health outcomes at admission: a prospective randomized study on patients with osteoarthritis of the knee joint

AIMS: To evaluate the effect of waiting on health-related quality of life (HRQoL), pain and physical function in patients awaiting primary total knee replacement (TKR) due to osteoarthritis. METHODS: Some 438 patients awaiting TKR were randomized to a short waiting time (WT) group (< or =3 months) or a non-fixed WT group. In the final assessment, 310 patients (213 women) with a mean age of 68 years were included. HRQoL was measured on being placed on the waiting list and again at hospital admission using the generic 15D. Patients' self-report pain and physical function were evaluated using a scale modified from the Knee Society Clinical Rating System. RESULTS: The median WTs for patients with short and non-fixed WT were 73 days (range 8-600 days) and 266 days (range 28-818 days), respectively. At admission, as assessed by the intention-to-treat analysis, there were no statistically significant differences between the groups in the 15D total score and disease-specific pain and function. CONCLUSIONS: Our study showed that longer WT did not result in worse pre-operative HRQoL.     

Rehabilitation treatment of ankylosis after relaxing and plastic operation of adhesion of knee extension apparatus

Baskground:Ankylosis is the result of adhesion of knee extension apparatus that is often the complications of trauma of femoral shaft and knee.Because ankylosis will impair the flexion of knee joint,postoperational exercise is the key to rebuild flexing function of knee joint.Objective:To investigate therapeutic effect of rehabilitation treatment on ankylosis after relaxing and plastic operation of adhesion of knee extension apparatus.Unit:Yuanbaoshan Ore Hospital of Chifeng City.Subjects:38 cases of ankylosis were investigated including 29 males,9 females aged 23-58 (mean:36) years old,with disease course 7 months-5 years.All cases were given operation and after operation fixed with plaster,fixing time:58-142 (mean:94) days.Mobility of knee joint before operation:4 cases over 50&;#176;,7 cases over 40&;#176;,others 5&;#176;-30&;#176;(mean:24&;#176;0.x-ray showed:no deformity of space,atrophy of quadriceps muscle of thigh,bad mobility of patella.Relaxing and plastic operation of adhesion of knee extension apparatus was given to all cases.Intervention:Knee joint was fixed at maxium flexing degree with solichocnemic plaster.Skin blood should be paid attention to.24h after operation affected limb was layed on removable orthodontic applicance at daytime,passive movement of joint was adopted,with painlessness as discipline for flexing,normally 10&;#176;-80&;#176;,increased successively.Knee joint was fixed at flexion position at nighttime.Exercise,twice a day,2-3h every time.Active exercise was adopted in intervals of passive exercise:kicking toes,straight leg elevating,After 2 weeks of passive exercise and 3 weeks of active exercise,patients took simple activity active movement mainly.Combined physical therapy:hot compression,keeping for 3 months.Result:Follow-up survey 9 months-3years(mean:1 year and 4 months).motion range:60&;#176;-130&;#176;(mean:110&;#176;).Conclusion: Function exercises after relaxing and plastic operation of adhesion could promote self-repairing of articular cartilage,accelerate healing of articular cartilage and peripheral tissue and prevent adhesion.     

Health related quality of life after lumbar disc surgery: A prospective study of 145 patients

Purpose:?This study compared health related quality of life (HRQOL) among lumbar disc surgery patients to general population, and assessed the relationships between HRQOL and other outcome measures 2 and 14 months after surgery.

Methods:?The 15D instrument was used to measure HRQOL in 145 lumbar disc surgery patients. Subjective outcome was also assessed by the Oswestry index, Short Depression Inventory (SDI) and pain, and objective outcome by trunk muscle strength and mobility of the spine.

Results:?The mean (SD) 15D score among the patients 2 months after surgery was 0.880 (0.104) compared to 0.941 (0.076) among general population (p?=?0.016). The 15D, Oswestry and SDI scores remained unchanged during the follow-up, while the improvements in the spine mobility and trunk muscle strength were significant. Back pain decreased by 68% and leg pain by 74% from preoperative level to 2 months check-up. Leg pain further decreased during the following 12 months, while back pain remained unchanged. HRQOL was associated with age, pain, Oswestry and SDI indices, but not with physical function.

Conclusion:?HRQOL measured by 15D was lower in the lumbar disc surgery patients compared to general population. 15D was associated with the subjective outcome measures of pain, Ostwestry and SDI indices, but not with the objective measures of physical function. Thus, a combination of “disease specific” and “generic” measures is recommended to be used to obtain more accurate information about the overall welfare of an individual.     

Novel biomechanics demonstrate gait dysfunction due to hamstring tightness

BACKGROUND: Children with cerebral palsy and hamstring tightness often demonstrate limited terminal swing knee extension. The conventional clinical measure of popliteal angle describes static hamstring tightness, but is not consistent with dynamic limitation. We hypothesize hamstring tightness, determined via modification of the conventional popliteal angle measure, is directly related to decreased terminal swing knee extension in children with cerebral palsy and normal magnitude knee flexion moments. METHODS: Six patients with cerebral palsy and six normal subjects were evaluated via physical examination and instrumented gait analysis. Physical examination included popliteal angle measures at first hamstring resistance to passive extension (R(1)), and end-range extension (R(2)) with the hip in varying degrees of flexion. Passive R(1) data were used to calculate regression equations to predict R(1) during gait, resulting in a novel measure of Available Knee Extension. Hamstring EMG was also compared. FINDINGS: R(1) during physical examination was significantly correlated with Available Knee Extension at terminal swing (Pearson r = -0.7251, P < 0.0001). Patients walked with significantly decreased velocity (0.959 vs. 1.27 m/s, P = 0.0002) and decreased knee extension at terminal swing (25.6 vs. 2.05 degrees, P < 0.0001), in the presence of normal knee flexion moments (-0.289 vs. -0.306 Nm/kg, P = 0.5009), and significantly decreased power absorption (-0.821 vs. -1.43 W/kg, P < 0.0001). Eleven of 12 patient knees demonstrated negative Available Knee Extension at terminal swing, with markedly limited knee extension. Five of 12 normal knees demonstrated negative Available Knee Extension, but this was near full extension. Hamstring EMG onset times were not significantly different. INTERPRETATION: We believe Available Knee Extension, defined on the basis of clinical measures of first resistance to hamstring stretch, provides a biomechanical link between physical examination findings and dynamic limitations in terminal swing knee extension.     

Is discharge knee range of motion a useful and relevant clinical indicator after total knee replacement? Part 2

Objective Knee range of motion (ROM) at discharge from acute care is used as a clinical indicator following total knee replacement (TKR) surgery. This study aimed to assess the clinical relevance of this indicator by determining whether discharge knee ROM predicts longer‐term knee ROM and patient‐reported knee pain and function. Methods A total of 176 TKR recipients were prospectively followed after discharge from acute care. Outcomes assessed included knee ROM and Oxford knee score post rehabilitation and 1 year post surgery. Discharge ROM and other patient factors were identified a priori as potential predictors in multiple linear regression modelling. Results A total of 133 (76%) and 141 (80%) patients were available for follow‐up post rehabilitation [mean postoperative week 8.1 (SD 2.7)] and at 1 year [mean postoperative month 12.1 (SD 1.4)], respectively. Greater discharge knee flexion was a significant (P < 0.001) predictor of greater post‐rehabilitation flexion but not 1‐year knee flexion (P < 0.083). Better discharge knee extension was a significant predictor of better post‐rehabilitation (P = 0.001) and 1‐year knee extension (P = 0.013). Preoperative Oxford score and post‐rehabilitation knee flexion independently predicted post‐rehabilitation Oxford score, and gender predicted 1‐year Oxford score. Discharge ROM did not significantly predict Oxford score in either model. Conclusion The finding that early knee range predicts longer‐term range provides clinical evidence favouring the relevance of discharge knee ROM as a clinical indicator. Although longer‐term patient‐reported knee pain and function were not directly associated with discharge knee ROM, they were associated with ROM when measured concurrently in the sub‐acute phase. No causal effect has been demonstrated, but the findings suggest it may be important for physiotherapists to maximize range in the early and sub‐acute periods.     

Health related quality of life after lumbar disc surgery: a prospective study of 145 patients

Purpose: This study compared health related quality of life (HRQOL) among lumbar disc surgery patients to general population, and assessed the relationships between HRQOL and other outcome measures 2 and 14 months after surgery.

Methods: The 15D instrument was used to measure HRQOL in 145 lumbar disc surgery patients. Subjective outcome was also assessed by the Oswestry index, Short Depression Inventory (SDI) and pain, and objective outcome by trunk muscle strength and mobility of the spine.

Results: The mean (SD) 15D score among the patients 2 months after surgery was 0.880 (0.104) compared to 0.941 (0.076) among general population (p = 0.016). The 15D, Oswestry and SDI scores remained unchanged during the follow-up, while the improvements in the spine mobility and trunk muscle strength were significant. Back pain decreased by 68% and leg pain by 74% from preoperative level to 2 months check-up. Leg pain further decreased during the following 12 months, while back pain remained unchanged. HRQOL was associated with age, pain, Oswestry and SDI indices, but not with physical function.

Conclusion: HRQOL measured by 15D was lower in the lumbar disc surgery patients compared to general population. 15D was associated with the subjective outcome measures of pain, Ostwestry and SDI indices, but not with the objective measures of physical function. Thus, a combination of “disease specific” and “generic” measures is recommended to be used to obtain more accurate information about the overall welfare of an individual.     

Quality of life and life-space mobility after total knee arthroplasty in patients with rheumatoid arthritis: a pilot case-controlled study

[Purpose] The purpose of this study was to identify factors inhibiting improvement in the quality of life after total knee arthroplasty in patients with rheumatoid arthritis. [Participants and Methods] This was a pilot case-control study. The sample comprised of five participants with rheumatoid arthritis and 11 participants with osteoarthritis, who underwent total knee arthroplasty. We compared the groups in terms of physical function, walking ability, Japanese Knee Osteoarthritis Measure, and Life-Space Assessment. Measurements were taken before surgery and at four weeks and five months post-surgery. All patients underwent rehabilitation for five months postoperatively, first as inpatients, and then as outpatients after discharge. [Results] In the period from 4 weeks to 5 months post-surgery, physical function improved similarly in both groups in terms of muscle strength and walking ability. Despite the patients with rheumatoid arthritis being younger, their self-health assessment score by the Japanese Knee Osteoarthritis Measure and measures of life-space mobility by Life-Space Assessment were lower. [Conclusion] It is important to consider exercise therapy, and gait instruction to alleviate anxiety about health status and improve the quality of life and life-space mobility in patients with rheumatoid arthritis who undergo total knee arthroplasty.     

Pain, lower-extremity muscle strength, and physical function among older Mexican Americans

OBJECTIVE: To examine the relation between pain on weight bearing, lower-extremity muscle strength, and physical function among older Mexican Americans. DESIGN: Cross-sectional study. SETTING: Five Southwestern states: Texas, New Mexico, Colorado, Arizona, and California. PARTICIPANTS: A population-based sample of 544 noninstitutionalized Mexican-American men and women age 71 years and older. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Pain on weight bearing, lower-extremity muscle strength, and physical function. RESULTS: Of the 544 subjects, 244 (44.9%) reported pain on weight bearing. Mean muscle strength in men ranged from 9.3 kg for knee extension, 12.8 kg for hip flexion, to 13.0 kg for hip abduction. In women, mean strength ranged from 6.6 kg for knee extension, 9.5 kg for hip flexion, to 8.6 kg for hip abduction. Mean of physical function score was 70.7 for men and 60.6 for women. Pain on weight bearing was negatively associated with summary lower-extremity muscle strength only in women (-.05, P < .001) after controlling for all covariates. Pain on weight bearing was negatively associated with physical function in both men (-15.33, P < .001) and women (-11.03, P < .001), and lower-extremity muscle strength was positively associated with physical function in both men (37.77, P < .001) and women (73.50, P < .001), after controlling for all covariates. CONCLUSIONS: Among older Mexican Americans, the presence of pain was associated with decreased muscle strength in women and decreased physical function in both men and women. High muscle strength was associated with high physical function in both men and women.     

Long-term gait biomechanics in level,uphill, and downhill conditions following anterior cruciate ligament reconstruction

BackgroundAltered gait biomechanics have been linked to post-traumatic knee osteoarthritis development following anterior cruciate ligament reconstruction surgery, but the persistence of aberrant gait biomechanics after the first year post-surgery is inconsistent in the literature. Gait biomechanics are typically evaluated on a level surface, but this task may not elucidate discrepancies in individuals further removed from surgery due to the simplicity of the task. Graded surfaces are common in real-world ambulation and may exacerbate aberrant gait biomechanics due to greater mechanical demands.MethodsForty-seven individuals post-anterior cruciate ligament reconstruction (4 ± 3 years post-surgery) and forty-seven uninjured controls completed gait analysis under level, uphill, and downhill conditions on an instrumented treadmill. Outcomes included knee flexion displacement and peak knee flexion angle, vertical ground reaction force, and knee extension and abduction moments.FindingsKnee extension moment and knee flexion displacement were lesser in the surgical limb compared to the contralateral during the downhill condition, with lesser knee flexion displacement also observed during the level condition. Additionally, knee extension moment was less symmetrical in the surgical group during both uphill and downhill conditions compared to controls. Knee flexion displacement was less symmetrical in the surgical group during both level and downhill conditions compared to controls.InterpretationGraded surfaces elucidate aberrant gait biomechanics in individuals more than 1 year post-anterior cruciate ligament reconstruction that are not apparent during level walking. These findings suggest that gait assessment on level surfaces may mask existing deficiencies, and warrant emphasizing ambulation of graded surfaces during anterior cruciate ligament rehabilitation.