Medial Knee Osteoarthritis Patients Research Articles

Knee

The October 2024 Knee Roundup360 looks at: Managing the unexpected: treatment of intraoperative medial collateral ligament injuries; Identifying subgroups of patients that may benefit from robotic arm-assisted total knee arthroplasty: secondary analysis of data from a randomized controlled trial; Cost-effectiveness of enoxaparin versus aspirin in the prevention of venous thromboembolism after total hip or knee arthroplasty: an analysis from the CRISTAL cluster-randomized trial; Cartilage regeneration and long-term survival in medial knee osteoarthritis patients treated with high tibial osteotomy and osteochondral autologous transfer system; Treatment of chronic and complex meniscal tears with arthroscopic meniscus repair augmented with collagen matrix wrapping: failure rate and functional outcomes; Long-term outcomes of multiligament knee injuries in American football players.

Bilateral Asymmetry in Knee and Hip Musculoskeletal Loading During Stair Ascending/Descending in Individuals with Unilateral Mild-to-Moderate Medial Knee Osteoarthritis

Most cases of unilateral knee osteoarthritis (OA) progress to bilateral OA within 10 years. Biomechanical asymmetries have been implicated in contralateral OA development; however, gait analysis alone does not consistently detect asymmetries in OA patient gait. Stair ambulation is a more demanding activity that may be more suited to reveal between-leg asymmetries in OA patients. The objective of this study was to investigate the between-leg biomechanical differences in patients with unilateral mild-to-moderate knee OA. Sixteen unilateral mild-to-moderate medial knee OA patients and 16 healthy individuals underwent kinematic and kinetic analysis of stair ascent and descent. Stair ascent produced higher loading and muscle forces in the unaffected limb compared to the OA limb, and stair descent produced lower loading on the OA limb compared to healthy subjects. These biomechanical differences were apparent in the ankle, knee, and hip joints. The implications of these findings are that OA patients rely more heavily on their unaffected sides than the affected side in stair ascent, a strategy that may be detrimental to the unaffected joint health. The reduction in affected limb loading in stair descent is thought to be related to minimizing pain.

Estimation of the External Knee Adduction Moment during Gait Using an Inertial Measurement Unit in Patients with Knee Osteoarthritis.

Although the external knee adduction moment (KAM) during gait was shown to be a quantitative parameter of medial knee osteoarthritis (OA), it requires expensive equipment and a dedicated large space to measure. Therefore, it becomes a major reason to limit KAM measurement in a clinical environment. The purpose of this study was to estimate KAM using a single inertial measurement unit (IMU) during gait in patients with knee OA. A total of 22 medial knee OA patients (44 knee joints) performed conventional gait analysis using three-dimensional (3D) motion capture system. At the same time, we attached commercial IMUs to six body segments (sternum, pelvis, both thighs, and both shanks), and IMU signals during gait were recorded synchronized with the motion capture system. The peak-to-peak difference of acceleration in the lateral/medial axis immediately after heel contact was defined as the thrust acceleration (TA). We hypothesized that TA would represent the lateral thrust of the knee during the stance phase and correlate with the first peak of KAM. The relationship between the peak KAM and TA of pelvis (R = 0.52, p < 0.001), shanks (R = 0.57, p < 0.001) and thighs (R = 0.49, p = 0.001) showed a significant correlation. The root mean square error (RMSE) of linear regression models of pelvis, shanks, and thighs to estimate KAM were 0.082, 0.079, and 0.084 Nm/(kg·m), respectively. Our newly established parameter TA showed a moderate correlation with conventional KAM. The current study confirmed our hypothesis that a single IMU would predict conventional KAM during gait. Since KAM is known as an indicator for prognosis and severity of knee OA, this new parameter has the potential to become an accessible predictor for medial knee OA instead of KAM.

MRI findings change after medial opening-wedge high tibial osteotomy for medial knee osteoarthritis

Purpose: Medial opening-wedge high tibial osteotomy (OWHTO) is a surgical procedure that aims to correct the weight-bearing axis of the knee, moving the loads laterally from the medial compartment. In many studies, it was reported that medial OWHTO improved pain in medial knee osteoarthritis (OA). But it isn’t unclear how MRI findings change and why knee pain improves after OWHTO. The purpose was to prospectively evaluate the compartmental changes of OWHTO for medial knee OA with MRI. Methods: 13 medial knee OA patients (mean age 61 ± 9.3 years) with 17 knees undergoing medial OWHTO were assessed pre- and postoperatively with MRI. The implant removal surgery was done 25.4 ± 9.8 months after OWHTO. Pain at rest and walking were assessed using a 0 to 100 Visual Analogue Scale (VAS). Postoperative MRI was done after the implant removal surgery. Subchondral bone marrow lesions (BMLs) area at the medial compartment was calculated through the slice which showed maximum size of BMLs area in the coronal plane using the fat-suppressed T2-weighted FSE images. The articular cartilage and synovitis were scored using Whole-Organ Magnetic Resonance Imaging Scores (WORMS). Femorotibial angle (FTA), the percentage of mechanical axis (%MA), VAS pain at rest, VAS pain at walking, BMLs area, articular cartilage score, synovitis score and relative percentage of medial meniscus extrusion were examined. Results: Preoperative and postoperative assessments of measurements are summarized in Table 1. FTA and %MA were corrected to 180 (IQR 180,183) and 65.8 (IQR 60.4, 69.4) respectively (p < 0.01). VAS pain at rest and walking were reduced after surgery (p<0.05, p<0.01 respectively). BMLs area at both femur and tibia reduced after surgery (p < 0.05). But lateral tibiofemoral joint (LTFJ) and patellofemoral joint (PFJ) articular cartilage score, synovitis score and relative percentage of medial meniscus extrusion weren’t improved after surgery. Conclusions: In this study, OWHTO improved VAS pain and reduced BMLs area. Maybe BMLs area can be associated with pain relief in knee OA after OWHTO. On the other hand, OWHTO couldn’t improve degenerative LTFJ and PFJ articular cartilage score, synovitis score and medial meniscus extrusion. But the further studies will be needed regarding synovitis and medial meniscus extrusion. Because in this study we didn’t use contrast-enhanced MRI, there were possibility that synovitis wasn’t assessed accurately. And also, regarding the meniscus extrusion, we need to assess that not only in a supine position but also in a standing position.Tabled 1Table 1. Details of assessments of measurementspreoperativepostoperativeFTA (°)180 (180, 183)170 (168, 171) **%MA (%)19.0 (13.9, 22.7)65.8 (60.4, 68.4) **VAS pain at rest (0-100)10 (2.5, 15)0 (0, 2.5) *VAS pain at walking (0-100)50 (30, 75)0 (0, 15) **BMLs area at medial femur (cm2)45.6 (0, 96.7)12.3 (6.7, 50.8) *BMLs area at tibia (cm2)52.0 (7.7, 131.6)28.9 (0, 63.6) *MTFJ articular cartilage score (0-30)13 (12, 16)12 (11, 18)LTFJ articular cartilage score (0-30)0 (0, 2)2 (1, 3) *PFJ articular cartilage score (0-24)3 (1, 4)6 (4, 6.5) **Synovitis score (0-3)1 (1, 2)1 (1, 2)Meniscus extrusion (%)52.8 (44.1, 60.7)47.1 (31.2, 62.5) Open table in a new tab

Does mobile-bearing have better flexion and axial rotation than fixed-bearing in total knee arthroplasty? A randomised controlled study based on gait

ObjectiveTo analyse the 6 degrees of freedom of the knee and gait data of patients with medial knee osteoarthritis before and after fixed-bearing (FB) and mobile-bearing (MB) total knee arthroplasty (TKA) ​and examine the influence of TKA on gait characteristics and the difference between FB and MB prosthesis. We also sought to explore the prosthesis options available for TKA in these patients. MethodsThirty patients who underwent TKA at the Department of Orthopedics at our hospital from June to October 2017 were included. All patients had a lower limb mechanical axis (hip-knee-ankle angle) of less than 180° which were regarded as genu varum knees and had medial knee osteoarthritis. Patients were randomised divided into the FB group ​and the MB group according to the knee prosthesis implanted. An infrared navigation three-dimensional portable knee motion analysis system (Opti-Knee®, Shanghai Innomotion, Inc.) was used to acquire data on the 6 degrees of freedom of both knees when walking on flat ground before and after surgery (angle of tibia relative to femur parameters: flexion-extension, internal rotation–external rotation, abduction–adduction; displacement parameters: anterior–posterior, proximal–distal, medial–lateral). Postoperative follow-up efficacy was assessed using the Oxford Knee Score system. ResultsThere were significant differences in the maximum values of the internal/external rotation and flexion/extension angle between patients post-TKA and the healthy population, p values were 0.007 and <0.001,respectively. The postoperative maximum values of genu varum and internal rotation in both FB [(−9.49 ​± ​5.99°), (−5.77 ​± ​3.42°), respectively] and MB [(−9.64 ​± ​4.83°), (−7.54 ​± ​4.51°), respectively] groups were lower than the preoperative ones [FB (−15.13 ​± ​6.78°), (−8.28 ​± ​4.83°); MB (−13.28 ​± ​3.98°), (−9.46 ​± ​4.99°), respectively] (p ​≤ ​0.001), while the postoperative maximum values of flexion angle and anterior displacement in both FB [(46.11 ​± ​4.14°), (0.71 ​± ​0.35 ​cm), respectively] and MB [(49.33 ​± ​3.98°), (0.75 ​± ​0.89 ​cm), respectively] groups were larger than the preoperative ones [FB (43.15 ​± ​3.77°), (0.26 ​± ​0.74 ​cm); MB (44.62 ​± ​5.92°), (0.33 ​± ​0.79°), respectively] (p ​≤ ​0.001). The postoperative range of flexion/extension angle in both FB (40.13 ​± ​4.14°) and MB (45.82 ​± ​3.76°) groups was significantly larger than the preoperative one [FB (36.17 ​± ​6.07°), MB (37.09 ​± ​3.93°), respectively] (p ​≤ ​0.001). There were also significant increases in range of anterior–posterior displacement in the FB group (0.85 ​± ​0.32 ​cm) postoperatively compared with the preoperative one (0.71 ​± ​0.92 ​cm) (p ​= ​0.016) ​and significant increases in range of medial-lateral displacement (0.64 ​± ​0.73 ​cm) in the MB group postoperatively compared with the preoperative one (0.52 ​± ​0.91 ​cm) (p ​= ​0.025). The mean flexion/extension angle of the MB group was significantly greater than the FB group after surgery in both the stance phase and the swing phase (p ​< ​0.001). There were significant differences in postoperative knee axial rotation during the gait cycle between the MB and FB groups (p ​= ​0.028) ​and that postoperative internal rotation of the tibia relative to the femur increased in the MB group. The Oxford Knee Score at the last follow-up visit about 7.5 months after surgery was 15.6 ​± ​1.3 and 15.1 ​± ​1.1 points for FB and MB groups, respectively. This difference was not significant (p ​= ​0.428). ConclusionsTKA can make the parameters of knee gait characteristics closer to the normal population. Medial knee osteoarthritis patients who received a MB prosthesis in TKA had better joint flexion function and axial rotation than the FB one. However, there is insufficient evidence to suggest that the MB prosthesis is a better option for patients with medial knee osteoarthritis. The translational potential of this articleTo date, no consensus for prosthesis selection in TKA has been established. This study found significant differences in joint flexion/extension angle and internal/external rotation during gait post-TKA surgery in medial knee osteoarthritis patients who received different prostheses. This will provide some references for prosthesis selection for a large number of genu varum patients in clinical practice.

Total knee arthroplasty for patients with medial knee osteoarthritis improves trunk movement during gait.

Previous studies have indicated that the kinematics of the knee joint affect the trunk and pelvis during gait. However, the factors that influence trunk movement in knee osteoarthritis patients during gait after surgery remain unclear. To examine the effect of total knee arthroplasty (TKA) on trunk movement during gait by comparing knee osteoarthritis patients with healthy controls. Fourteen medial knee osteoarthritis patients who underwent initial unilateral TKA and 11 controls participated in this study. Knee and hip joint flexion and trunk and pelvic tilts during gait were acquired using a three-dimensional motion analysis system. Knee joint range of motion, pain, and kinematic data were collected preoperatively and 1 year postoperatively for knee osteoarthritis patients. Knee extension limitation and pain significantly improved postoperatively compared with preoperative stages. Preoperatively, the peak anterior trunk tilt during the stance phase was significantly larger in osteoarthritis patients than in controls. The peak anterior trunk tilt during the stance phase was significantly smaller postoperatively than at preoperative stages. These results suggest that after TKA, the trunk movements of knee osteoarthritis patients were approximately equal to those of controls, with improvement in clinical outcomes such as knee extension limitation and pain.

Change in activity following administration of a lateral wedge insole: analysis from the Inrespond trial

Change in activity following administration of a lateral wedge insole: analysis from the Inrespond trial

Lower-limb muscle function during gait in varus mal-aligned osteoarthritis patients.

This study quantified the contributions by muscular, gravitational and inertial forces to the ground reaction force (GRF) and external knee adduction moment (EKAM) for knee osteoarthritis (OA) patients and controls walking at similar speeds. Gait data for 39 varus mal-aligned medial knee OA patients and 15 controls were input into musculoskeletal models to calculate the contributions of individual muscles and gravity to the fore-aft (progression), vertical (support), and mediolateral (balance) GRF, and the EKAM. The temporal patterns of contributions to GRF and EKAM were similar between the groups. Magnitude differences in GRF contributions were small but some reached significance. Peak GRF contributions were lower in patients except hamstrings in early-stance progression (p < 0.001) and gastrocnemius in late-stance progression (p < 0.001). Both EKAM peaks were higher in patients, due mainly to greater adduction contribution from gravity (p < 0.001) at the first peak, and lower abduction contributions from soleus (p < 0.001) and gastrocnemius (p < 0.001) at the second peak. Gluteus medius contributed most to EKAM in both groups, but was higher in patients during mid-stance only (p < 0.001). Differences in GRF contributions were attributed to altered quadriceps-hamstrings action as well as compensatory adaptation of the ankle plantarflexors to reduced gluteus medius action. The large effect of varus mal-alignment on the frontal-plane moment arms of the gravity, soleus, and gastrocnemius GRF contributions about the knee explained greater patient EKAM. Our results shed further light on how the EKAM contributes to altered knee-joint loads in OA and why some interventions may affect different portions of the EKAM waveform. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Combined effects of knee brace, laterally wedged insoles and toe-in gait on knee adduction moment and balance in moderate medial knee osteoarthritis patients

ObjectiveTo test the hypothesis that toe-in gait (TI) will further reduce first peak (Knee Adduction Moment) KAM and decrease balance when combined with a knee brace (KB) and laterally wedged insoles (LWI) in medial knee osteoarthritis (kOA) patients. ParticipantsTwenty patients with bilateral symptomatic medial kOA. Interventions4-point leverage-based KB, full-length LWI with 5° inclination and toe-in gait (TI). Main outcome measuresFirst and second peak knee adduction moment (fKAM and sKAM respectively), balance and pain. MethodsThe fKAM and sKAM were determined from 3-dimensional gait analysis with six randomized conditions: (1) N (without any intervention), (2) KB, (3) KB + TI, (4) LWI, (5) LWI + TI, (6) KB + LWI + TI. Balance was assessed by Biodex Balance System using three stability settings, (i) Static (ii) Moderate dynamic setting for fall risk (FR12) and (iii) High dynamic setting for fall risk (FR8). ResultsThe reduction in fKAM and sKAM was greatest (19.75% and 12%) when TI was combined with KB and LWI respectively. No change in balance was observed when TI combined with KB, and LWI and when used concurrently with both the orthosis at static and FR12 conditions. Significant balance reduction was found at FR8 for KB + TI (22.22%), and KB + LWI + TI (35.71%). Pain increased significantly for KB (258%), KB + TI (305%), LWI + TI (210%) and KB + LWI + TI (316%). LWI showed no effect on pain. ConclusionsThere is a synergistic effect of TI when combined with KB and LWI concurrently in sKAM reduction. However, the concurrent use of TI, KB and LWI decreases balance and pain as assessed on a highly dynamic platform.

Effects of different foot progression angles and platform settings on postural stability and fall risk in healthy and medial knee osteoarthritic adults.

This study aims to investigate the effects of varying toe angles at different platform settings on Overall Stability Index of postural stability and fall risk using Biodex Balance System in healthy participants and medial knee osteoarthritis patients. Biodex Balance System was employed to measure postural stability and fall risk at different foot progression angles (ranging from -20° to 40°, with 10° increments) on 20 healthy (control group) and 20 knee osteoarthritis patients (osteoarthritis group) randomly (age: 59.50 ± 7.33 years and 61.50 ± 8.63 years; body mass: 69.95 ± 9.86 kg and 70.45 ± 8.80 kg). Platform settings used were (1) static, (2) postural stability dynamic level 8 (PS8), (3) fall risk levels 12 to 8 (FR12) and (4) fall risk levels 8 to 2 (FR8). Data from the tests were analysed using three-way mixed repeated measures analysis of variance. The participant group, platform settings and toe angles all had a significant main effect on balance ( p ≤ 0.02). Platform settings had a significant interaction effect with participant group F(3, 144) = 6.97, p < 0.01 and toe angles F(21, 798) = 2.83, p < 0.01. Non-significant interactions were found for group × toe angles, F(7, 266) = 0.89, p = 0.50, and for group × toe angles × settings, F(21, 798) = 1.07, p = 0.36. The medial knee osteoarthritis group has a poorer postural stability and increased fall risk as compared to the healthy group. Changing platform settings has a more pronounced effect on balance in knee osteoarthritis group than in healthy participants. Changing toe angles produced similar effects in both the participant groups, with decreased stability and increased fall risk at extreme toe-in and toe-out angles.

Mechanically stimulated biomarkers signal cartilage changes over 5 years consistent with disease progression in medial knee osteoarthritis patients.

Using serum biomarkers to assess osteoarthritis (OA) disease state and risks of progression remain challenging. This study tested the hypothesis that changes to serum biomarkers in response to a mechanical stimulus in patients with medial knee OA signal cartilage thickness changes 5 years later. Specifically, serum concentrations of a collagen degradation marker (C1,2C) and a chondroitin sulfate synthesis marker (CS846) were measured 0.5 and 5.5 hours after a 30-min walk in 16 patients. Regional cartilage thickness changes measured from magnetic resonance images obtained at study entry and at 5-year follow-up were tested for correlations with baseline biomarker changes after mechanical stimulus, and for differences between groups stratified based on whether biomarker levels increased or decreased. Results showed that an increase in the degradation biomarker C1,2C correlated with cartilage thinning of the lateral tibia (R = -0.63, p = 0.009), whereas an increase in the synthesis marker CS846 correlated with cartilage thickening of the lateral femur (R = 0.76, p = 0.001). Changes in C1,2C and CS846 were correlated (R2 = 0.28, p = 0.037). Subjects with increased C1,2C had greater (p = 0.05) medial tibial cartilage thinning than those with decreased C1,2C. In conclusion, the mechanical stimulus appeared to metabolically link the biomarker responses where biomarker increases signaled more active OA disease states. The findings of medial cartilage thinning for patients with increases in the degradation marker and correlation of cartilage thickening in the less involved lateral femur with increases in the synthetic marker were consistent with progression of medial compartment OA. Thus, the mechanical stimulus facilitated assessing OA disease states using serum biomarkers. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:891-897, 2018.

Effects of toe-out and toe-in gait with varying walking speeds on knee joint mechanics and lower limb energetics

Toe-out/-in gait has been prescribed in reducing knee joint load to medial knee osteoarthritis patients. This study focused on the effects of toe-out/-in at different walking speeds on first peak knee adduction moment (fKAM), second peak KAM (sKAM), knee adduction angular impulse (KAAI), net mechanical work by lower limb as well as joint-level contribution to the total limb work during level walking.Gait analysis of 20 healthy young adults was done walking at pre-defined normal (1.18m/s), slow (0.85m/s) and fast (1.43m/s) walking speeds with straight-toe (natural), toe-out (15°>natural) and toe-in (15°<natural). Repeated measure ANOVA (p<0.05) with post-hoc Tukey’s test was applied for statistical analysis.Toe-out gait increased fKAM at all walking speeds (highest at normal speed) while toe-in gait reduced fKAM at all speeds (highest at fast walking speed). Toeing-in reduced KAAI at all speeds while toeing-out affected KAAI only at normal speed. Increasing walking speed generally increased fKAM for all foot positions, but it did not affect sKAM considerably. Slowing down the speed, increased KAAI significantly at all foot positions except for toe-in. At slow walking speed, hip and knee joints were found to be major energy contributors for toe-in and toe-out respectively. At higher walking speeds, these contributions were switched. The ankle joint remained unaffected by changing walking speeds and foot progression angles.Toe-out/-in gait modifications affected knee joint kinetics and lower limb energetics at all walking speeds. However, their effects were inconsistent at different speeds. Therefore, walking speed should be taken into account when prescribing toe-out/-in gait.

Dynamic activity of unloader knee braces in genu varum subjects: New insights to improve compliance in medial knee osteoarthritis patients?

Using unloader knee braces with 3-point pressure in knee osteoarthritis patients is debated. The main reason is discomfort resulting in poor compliance. Studying the external knee adduction moment (EKAM) curve, gold standard in the medial knee load estimation, should be helpful to reduce this discomfort. Reducing constraint solely during the stance phase of gait (combined with an inactivation during large knee flexion) should indeed considerably improve comfort. Thus, the objective of this study was to validate both a method for measuring dynamic activity of new unloader knee braces and to highlight the biomechanical effectiveness of these orthoses. A specific tool incorporated into the brace at the leg interface was developed to quantify knee moments in situ. This tool was beforehand validated in accuracy and retest reliability A kinematic and kinetic analysis was performed on 8 healthy subjects (genu varum) throughout 7 knee valgus braces conditions (and a control condition without orthosis). Each orthosis was endowed of one, two or three mechanisms resulting in all possible combinations (valgus pad and/or cable on the external hinge and/or distraction on the medial hinge). The relative absolute mean bias of the tool was approximatively 4% (accuracy) and the standard error of measurement was close to 1.3% (retest reliability). Femoro-tibial angle in static position, 1st and 2nd EKAM pics, level arm and adduction angle at pics moment as well as maximum knee flexion were significantly reduced by some orthosis ( P < 0.001). The valgus orthosis moment varied significantly at 2nd EKAM pic depending on to the orthosis worn ( P < 0.006). Reported accuracy and retest reliability appear suitable to measure dynamic constraints induced by a knee orthosis. Thereby, biomechanical parameters allow us to point out the benefit of some new unloading knee orthoses, especially the device based on both lateral valgus pad and medial distraction.

Use of Two-Piece Foot Orthoses to Adjust Lateral Inclination Angle in Medial Knee Osteoarthritis Treatment

ABSTRACT Introduction Individualization of lateral inclination of foot orthoses (FO) is necessary to optimize the reduction of knee adduction moment (KAM) in medial knee osteoarthritis patients. The trial-and-error (or iterative) method is generally used for this purpose. Two kinds of orthoses can be used: several one-piece lateral FO (each with a different inclination height) for each patient or a two-piece lateral FO, that is, FO plus several laterally wedged insoles with different heights. The aim of this study was to determine whether comfort and mechanical impact on the knee and ankle are similar with the use of one-piece versus two-piece lateral FO during gait. Material and Methods Gait analysis was performed on 17 patients affected by medial knee osteoarthritis (grade II–III). Discomfort, frontal plane kinematics, and kinetics of the ankle and knee joints were compared in three conditions: without orthosis, with lateral customized FO, and with a combination of lateral wedge insoles and customized FO without lateral inclination. Lateral inclination was customized according to the orthotist's experience. Results One- and two-piece lateral customized FO had the same effect on the knee loading (p &gt; 0.05). However, both conditions with FO led to similar significant differences in knee adduction and ankle eversion moment compared with the without-orthosis condition (p &lt; 0.05; effect size from 0.05 to 0.40). Conclusions These results will be valuable for orthotists who make customized orthoses (with arch support) to reduce KAM in patients with medial knee osteoarthritis. Manufacturing two-piece orthoses is practical and economical: the customized FO can be kept and the wedge insole repeatedly replaced until the patient's pain is relieved.

Identification of a novel target, FoxA2, in the onset and development of osteoarthritis

Identification of a novel target, FoxA2, in the onset and development of osteoarthritis

Greater Step Widths Reduce Internal Knee Abduction Moments in Medial Compartment Knee Osteoarthritis Patients During Stair Ascent

Increased step widths have been shown to reduce peak internal knee abduction moments in healthy individuals but not in knee osteoarthritis patients during stair descent. This study aimed to assess effects of increased step widths on peak knee abduction moments and associated variables in adults with medial knee osteoarthritis and healthy older adults during stair ascent. Thirteen healthy older adults and 13 medial knee osteoarthritis patients performed stair ascent using preferred, wide, and wider step widths. Three-dimensional kinematics and ground reaction forces (GRFs) using an instrumented staircase were collected. Increased step width reduced first and second peak knee abduction moments, and knee abduction moment impulse. In addition, frontal plane GRF at time of first and second peak knee abduction moment and lateral trunk lean at time of first peak knee abduction moment were reduced with increased step width during stair ascent in both groups. Knee abduction moment variables were not different between knee osteoarthritis patients and healthy controls. Our findings suggest that increasing step width may be an effective simple gait alteration to reduce knee abduction moment variables in both knee osteoarthritis and healthy adults during stair ascent. However, long term effects of increasing step width during stair ascent in knee osteoarthritis and healthy adults remain unknown.

The use of a lateral wedge insole to reduce knee loading when ascending and descending stairs in medial knee osteoarthritis patients

BackgroundStair climbing is a challenging task to the elderly being the task with the first complaint in patients with mild to moderate knee osteoarthritis. Stair climbing results in around six times more compressive load transmitted through the knee joint than walking on level ground. The purpose of this study was to assess whether lateral wedge insoles would reduce medial compartment knee loading when ascending and descending stairs in patients with medial knee osteoarthritis. MethodsEight patients with medial knee osteoarthritis were tested in random order with and without a pair of 5° off-the-shelf lateral wedge insoles for two separate activities (stair ascent and stair descent). Kinematic and kinetic data were collected for the lower extremity using a sixteen camera motion capture system and two force plates. Primary outcome measures were the external knee adduction moment and the knee adduction angular impulse. FindingsDuring stair ascent and descent, lateral wedge insoles significantly (P<0.05) reduced the 1st peak external knee adduction moment in early stance (ascent 6.8%, descent 8.4%), the trough in mid stance (ascent 13%, descent 10.7%), 2nd peak in the late stance (ascent 15%, descent 8.3%) and the knee adduction angular impulse compared to the control (standard shoe) with large effect sizes (0.75–0.95). InterpretationIn this first study on stairs, lateral wedge insoles consistently reduced the overall magnitude of medial compartment loading during stair ascent and descent. Further research is needed to determine the relationship of this with clinical results when ascending and descending stairs with lateral wedge insoles.

Contralateral cane use and knee joint load in people with medial knee osteoarthritis: the effect of varying body weight support

To evaluate the effect of varying body weight support (BWS) with contralateral cane use on medial knee load, measured by external knee adduction moment (KAM), in medial knee osteoarthritis (OA) participants. Influences of cane use technique, pain and malalignment on the cane's load-reducing effects were investigated. Participants (n=23) underwent three-dimensional gait analysis to measure KAM peaks (early and late stance) and impulse. Unaided walking was firstly analyzed. Following cane use training, participants placed pre-determined magnitudes of BWS through the cane (10%, 15% and 20% in random order), with visual feedback provided via a force-instrumented cane and projection screen. Contributions of cane use technique (peak BWS magnitude and timing, cane impulse (BWS∗time) anterior and lateral cane distance from limb) and Western Ontario McMaster Universities OA Index (WOMAC) pain and malalignment to KAM outcomes were evaluated using linear mixed models. Cane use reduced all KAM variables, with a dose-response effect apparent. Cane BWS impulse was important in reducing the early stance peak KAM (P<0.001), peak BWS for late stance KAM (P<0.001) and both BWS measures for KAM impulse reductions (P<0.001). Variables contributing to efficacy of load-reduction differed across outcomes. Generally, greater reductions were achieved with longer lateral cane distances, peak BWS timing similar to KAM peaks, and shorter anterior cane distances. Greater pain and varus alignment improved load-reduction for some outcomes. Contralateral cane use significantly reduced medial knee load, with a dose-response effect. Medial knee OA patients should be encouraged to maintain greater BWS across stance, with cane placement more lateral for optimum benefit.

Gait changes in patients with knee osteoarthritis are replicated by experimental knee pain

Medial knee osteoarthritis (OA) is characterized by pain and associated with abnormal knee moments during walking. The relationship between knee OA pain and gait changes remains to be clarified, and a better understanding of this link could advance the treatment and prevention of disease progression. This study investigated changes in knee moments during walking following experimental knee pain in healthy volunteers, and whether these changes replicated the joint moments observed in medial knee OA patients. In a crossover study, 34 healthy subjects were tested on 3 different days; gait analyses were conducted before, during, and after pain induced by hypertonic saline injections (0.75 ml) into the infrapatellar fat pad. Isotonic saline and sham injections were used as control conditions. Peak moments in frontal and sagittal planes were analyzed. The results were compared with data from 161 medial knee OA patients. The patients were divided into less severe OA and severe OA categories, which was based on radiographic disease severity of the medial compartment. Experimental knee pain led to reduced peak moments in the frontal and sagittal planes in the healthy subjects, which were similar to the patterns observed in less severe OA patients while walking at the same speed. In healthy subjects, pain was associated with reductions in knee joint moments during walking in a manner similar to less severe knee OA patients. The experimental model may be used to study mechanically-driven knee OA progression and preventive measures against abnormal joint loading in knee OA.

Does joint alignment affect the T2 values of cartilage in patients with knee osteoarthritis?

To assess the relationship between T2 values of femorotibial cartilage and knee alignment in patients with clinical symptoms of medial osteoarthritis (OA). Twenty-four patients (mean age +/- standard deviation, 62.5 +/- 9.9 years) with clinical symptoms of medial knee OA, 12 with varus and 12 with valgus alignment of the femorotibial joint, were investigated on 3T MR using a 2D multi-echo spin echo (MESE) sequence for T2 mapping. Analysis of covariance, Spearman correlation coefficients, exact Mann-Whitney tests, and Fisher's exact tests were used for statistical analysis. Overall the T2 values of cartilage in the medial compartment (median +/- interquartile-range, 49.44 +/- 6.58) were significantly higher (P = 0.0043) than those in the lateral compartment (47.15 +/- 6.87). Patients with varus alignment (50.83 +/- 6.30 ms) had significantly higher T2 values of cartilage (P < 0.0001) than patients with valgus alignment (46.20 +/- 6.00 ms). No statistically significant association between the T2 values of cartilage (in either location) and the Kellgren Lawrence score was found in the varus or in the valgus group. T2 measurements were increased in medial knee OA patients with varus alignment, adding support to the theory of an association of OA and joint alignment.