Relationship between Fear-Avoidance Beliefs and Muscle Co-Contraction in People with Knee Osteoarthritis.

Excessive muscle co-contraction is one of the factors related to the progression of knee osteoarthritis (OA). A previous study demonstrated that pain, joint instability, lateral thrust, weight, and lower extremity alignment were listed as factors affecting excessive co-contraction in knee OA. However, this study aimed to assess the association between fear-avoidance beliefs and muscle co-contraction during gait and stair climbing in people with knee OA. Twenty-four participants with knee OA participated in this cross-sectional study. Co-contraction ratios (CCRs) were used to calculate muscle co-contraction during walking and stair climbing, using surface electromyography. Fear-avoidance beliefs were assessed by the Tampa Scale for Kinesiophobia-11 (TSK-11) for kinesiophobia and the Pain Catastrophizing Scale (PCS) for pain catastrophizing. Secondary parameters that may influence co-contraction, such as degree of pain, lateral thrust, weight, and lower extremity alignment, were measured. The relationships between the CCR during each movement, TSK-11, and PSC were evaluated using Spearman's rank correlation coefficient and partial correlation analysis, adjusted by weight and lower extremity alignment. Partial correlation analysis showed a significant correlation only between medial muscles CCR and TSK-11 during stair descent (r = 0.54, p < 0.05). Our study revealed that kinesiophobia could be associated with co-contraction during stair descent in people with knee OA.

Association of the Degree of Varus Thrust during Gait Assessed by an Inertial Measurement Unit with Patient-Reported Outcome Measures in Knee Osteoarthritis.

This study aimed to assess the association between the degree of varus thrust (VT) assessed by an inertial measurement unit (IMU) and patient-reported outcome measures (PROMs) in patients with knee osteoarthritis. Seventy patients (mean age: 59.8 ± 8.6 years; women: n = 40) were instructed to walk on a treadmill with an IMU attached to the tibial tuberosity. For the index of VT during walking (VT-index), the swing-speed adjusted root mean square of acceleration in the mediolateral direction was calculated. As the PROMs, the Knee Injury and Osteoarthritis Outcome Score were used. Data on age, sex, body mass index, static alignment, central sensitization, and gait speed were collected as potential confounders. After adjusting for potential confounders, multiple linear regression analysis revealed that the VT-index was significantly associated with the pain score (standardized ß = -0.295; p = 0.026), symptoms score (standardized ß = -0.287; p = 0.026), and activities of the daily living score (standardized ß = -0.256; p = 0.028). Our results indicated that larger VT values during gait are associated with worse PROMs, suggesting that an intervention to reduce VT might be an option for clinicians trying to improve PROMs.

Applied Assessment Method for Varus Thrust during Walking in Patients with Knee Osteoarthritis Using Acceleration Data Measured by an Inertial Measurement Unit.

We developed a novel quantitative method to assess varus thrust during walking using acceleration data obtained from an inertial measurement unit (IMU). This study aimed to examine the reliability of the developed index and to evaluate its ability to distinguish patients with knee osteoarthritis (OA) with varus thrust from healthy adults. Overall, 16 patients with knee OA and 16 healthy adults walked on a treadmill with IMUs attached to the tibial tuberosity and lateral femoral condyle. As an index of varus thrust, we used the root mean square (RMS) of acceleration in the mediolateral direction. This value was adjusted by dividing it by swing speed while walking (adjusted RMS, A-RMS) because the RMS of the acceleration was strongly coupled with the speed of motion. The intraclass correlation coefficients of A-RMS of the tibia and femur were 0.85 and 0.73, respectively. Significant differences were observed in the A-RMSs of the tibia and femur, with large effect sizes between the patients with knee OA and healthy adults (Cohen's d: 1.23 and 0.97, respectively). Our results indicate that A-RMS has good test-retest reproducibility and can differentiate patients with varus thrust from healthy adults.

Exploring the Potential of Lateral Wedge Insoles in Alleviating Bone Marrow Lesions in End-Stage Knee Osteoarthritis: A Preliminary Case Report.

The efficacy of lateral wedge insoles (LWIs) in patients with end-stage knee osteoarthritis (OA) is unclear. A 43-year-old male underwent two anterior cruciate ligament reconstructions in his right knee and was later diagnosed with end-stage knee OA. An LWI combining arch support with a lateral heel wedge was fabricated for this patient and used over 12 months. As a result, after 12 months, the bone marrow lesion (BML), as measured by the magnetic resonance imaging Osteoarthritis Knee Score (MOAKS), was downgraded from grade 2 to grade 1. The use of LWI in a patient with end-stage knee OA showed lower co-contraction ratios in knee muscles even after 12 months. The results provide preliminary evidence suggesting the use of LWI in patients with end-stage knee OA has potential benefits for reducing BML.

Differences in self-reported signs related to central sensitization and pressure pain threshold related to knee osteoarthritis and sarcopenia.

PURPOSE: Neuroinflammation, which occurs in knee osteoarthritis and sarcopenia, has attracted attention as a mechanism of central sensitization, but the relationship between central sensitization and these conditions has not been widely studied. This study investigates differences in self-reported signs of central sensitization and pressure pain threshold in individuals with knee osteoarthritis and sarcopenia. METHODS: We examined 340 patients (mean age ± standard deviation: 76 ± 5.9, women were 86.9%) with knee osteoarthritis scheduled to undergo total knee arthroplasty. For comparison, 129 community-dwelling older people (mean age ± standard deviation: 76 ± 5.5, women were 68.9%) individuals without a history of knee osteoarthritis or any other diagnosed illnesses were matched for age and sex. We assessed central sensitization inventory-9, pressure pain threshold, pain-related factors, skeletal muscle mass index, and hand grip strength. ANCOVA using 2 (patients with knee osteoarthritis and community older people without knee osteoarthritis) × 2 (sarcopenia and robust) was performed to assess outcome measurements. RESULTS: The prevalence of sarcopenia among patients with knee osteoarthritis was 50.3%. ANCOVA revealed an interaction effect for the central sensitization inventory-9. For the main effect of knee osteoarthritis, there was a significant difference in central sensitization inventory-9, and for the main effect of sarcopenia, there was a significant difference in pressure pain threshold. CONCLUSIONS: Discrepancies in the evaluation of central sensitization were identified between knee osteoarthritis and sarcopenia. Individuals with knee osteoarthritis had elevated score of self-reported indications of central sensitization, whereas sarcopenic patients had reduced pressure pain thresholds.

Japanese physical therapist's evidence-to-practice gap in knee osteoarthritis clinical practice guidelines: A cross-sectional study.

OBJECTIVE: As management for osteoarthritis, clinical practice guidelines (CPGs) have been published worldwide with the aim of attaining optimal treatment and rehabilitation. However, we suspect a lack of knowledge of and/or adherence to osteoarthritis CPGs in physiotherapists' clinical practice. There may be an evidence-to-practice gap in knee osteoarthritis rehabilitation among Japanese physiotherapists. Therefore, we aimed to measure the level of knowledge and adherence to osteoarthritis CPGs within a cohort of Japanese physiotherapists. METHODS: An online survey was created based on three appropriate and high-quality CPGs. The first two sections comprised 23 statements, and participants responded via a five-point Likert scale ("completely disagree" to "completely agree"). Consensus was defined as ≥70% agreement with a statement. In the second section, participants read clinical scenarios and selected what they considered to be the most appropriate management and interventions. RESULTS: The survey was completed by 558 Japanese physiotherapists. The mean age of the participants included in the analysis was 34.8 years, 61 participants were female (13.7%). Consensus was attained in just 12 out of 23 items (52%). In the second section, none of the physiotherapists were considered to have good knowledge of CPGs, 85.2% were considered to have only partial knowledge, and 14.8% had no knowledge. Familiarity with the CPGs was therefore poor and there was clearly poor adherence to the recommended rehabilitation guidelines. CONCLUSIONS: The level of knowledge and adherence to osteoarthritis CPGs within our cohort was poor, suggesting an evidence-to-practice gap in rehabilitation for knee osteoarthritis among Japanese physiotherapists.

Knee-related disability was largely influenced by cognitive factors and disturbed body perception in knee osteoarthritis.

The aim of this study was to explore the existence of subgroups in a cohort of people with knee osteoarthritis (OA) based upon data from multiple pain-related variables and to profile identified clusters according to levels of pain intensity and knee-related disability. Three hundred and three people with knee OA were recruited. Latent profile analysis was used to confirm the optimal number of knee OA subgroups. Body mass index, radiographic knee OA severity, pain catastrophizing, pain related self-efficacy, and knee specific self-perception, were incorporated into the model. Cluster, demographic and clinical variables were compared between the resulting classes. Four distinct classes were identified. Cluster 1 (28.7%) represented early radiographic OA, and moderate pain intensity, disability and cognitive and perceptual dysfunction. Cluster 2 (18.8%) showed advanced radiographic OA, and moderate pain intensity, disability and cognitive and perceptual dysfunction. Cluster 3 (34.3%) represented various levels of radiographic OA, and the lowest pain intensity, disability and cognitive and perceptual dysfunction. Cluster 4 (18.1%) represented various levels of radiographic OA, the highest disability and cognitive and perceptual dysfunction. Considering cognitive factors and disturbed body perception may help to explain the phenomenon of the discrepancy between the knee-related disability and the severity of radiographic knee OA.

Identifying participants with knee osteoarthritis likely to benefit from physical therapy education and exercise: A hypothesis-generating study.

BACKGROUND: The purpose of this investigation was to undertake a hypothesis-generating study to identify candidate variables that characterize people with knee osteoarthritis who are most likely to experience a positive response to exercise. METHODS: One hundred and fifty participants with knee osteoarthritis participated in this observational, longitudinal study. All participants received a standard exercise intervention that consisted of 20-min sessions two to three times a week for three months. The classification and regression tree methodology (CART) was used to develop prediction of positive clinical outcome. Positive pain and disability outcomes (dependent variables) were defined as an improvement in pain intensity by >50% or an improvement of five or more on the Oxford knee score, respectively. The predictor variables considered included age, sex, body mass index, knee osteoarthritis severity (Kellgren/Lawrence grade), pain duration, use of medication, range of knee motion, pain catastrophizing, self-efficacy and knee self-perception. RESULTS: Fifty-five participants (36.6%) were classified as responders for pain intensity and 36.6% were classified as responders for disability. The CART model identified impairments in knee self-perception and knee osteoarthritis severity as the discriminators for pain intensity reduction following exercise. No variables predicted reduction of disability level following exercise. CONCLUSIONS: Such findings suggest that both body perception and osteoarthritis severity may play a role in treatment outcome with exercise. It also raises the possibility that those with higher levels of disrupted body perception may need additional treatment targeted at restoring body perception prior to undertaking exercise. SIGNIFICANCE: Regardless age, sex, body mass index, pain duration, use of medication, knee range of motion, pain catastrophizing and self-efficacy, participants with knee osteoarthritis who report low levels of body perception disruption (a FreKAQ score ≦ 17) and minimal structural changes (KL grade I) demonstrate significantly better outcomes from exercise therapy than other participants.

"But it feels swollen!": the frequency and clinical characteristics of people with knee osteoarthritis who report subjective knee swelling in the absence of objective swelling.

INTRODUCTION: There are complex interactions between pain and perceptions of the painful body part in musculoskeletal disorders, and disruption of various body representations in people with chronic pain. OBJECTIVES: The purpose of this study was to investigate how frequently people with knee osteoarthritis (OA) complain of swelling without objective evidence of swelling, and describe the clinical characteristics of this population. METHODS: Forty-six people with knee OA (68.1 ± 8.8 years) participated in this cross-sectional study. Subjective and objective swelling was evaluated by knee-specific body perception questionnaire and ultrasonography, respectively. Pain intensity, disability, pain-related beliefs, 2-point discrimination threshold, and quadriceps muscle strength were also evaluated. RESULTS: Approximately 1/3 of participants (n = 15) had subjective feelings of knee swelling in the absence of objective swelling (S only). Fifteen participants had both subjective and objective knee swelling (S + O group) and 16 had neither subjective nor objective knee swelling (No S/O group). Participants in the S only group had similar pain or disability as those in the S + O group but had more severe pain or disability than those with in the No S/O group. Those in the S only group also had larger 2-point discrimination distance threshold at the medial knee (impaired tactile acuity) than those in the S + O group and had more dysfunctional pain catastrophizing and pain-related self-efficacy than both other groups. CONCLUSION: Our results suggest that about 30% of people with knee OA perceive swelling of the knee in the absence of any objective swelling and that this is accompanied by severe pain and functional disability. Considering altered body image of the knee may reveal relevant treatment-based subgroups in people with knee OA.

A case of cerebral sinus thrombosis developed during a high-altitude expedition to Gasherbrum I.

We report a case of cerebral sinus thrombosis, which is a rare but serious complication that may develop during high-altitude climbing. A climber who reached the summit of Gasherbrum I (8068 m) suffered from motor weakness and gait disturbance as he descended from the peak. Within a few days, the symptoms progressed until he could not walk. Following a difficult and week-long rescue mission by his colleagues, he was hospitalized and diagnosed with thrombosis at the superior sagittal and right transverse sinuses. Climbers and rescuers should know the risk factors of this complication, such as hemoconcentration, procoagulability, and dehydration.