Adaptive patterns of movement during stair climbing in patients with knee osteoarthritis

The purpose of this study was to determine if there is a distinctive characteristic in the pattern of movement (forward trunk lean to reduce demand on the quadriceps muscle) during stair climbing in patients with knee osteoarthritis (OA) that is associated with the severity of the disease. Twenty‐three patients with radiographically diagnosed knee OA and 20 physically active adults performed stair ascending trials without support at their self‐selected speed. Standard gait analysis was used to calculate three‐dimensional lower extremity joint kinematics and kinetics. Forward trunk lean, or trunk flexion, was defined as the sagittal plane projection of the angle between a line connecting the midpoint of the trans‐acromion line and the midpoint of the trans‐iliac crest line and the global vertical axis. Patients with more severe knee OA (KL ≥ 3) had greater forward trunk lean (+6.3°, p = 0.045) and lower knee net quadriceps moments (?35.2%, p = 0.001) than controls. In more severe patients, the forward trunk lean was correlated with a reduction in the net quadriceps moment during stair climbing (R² = 0.590, p = 0.006). The results of this study identified a distinctive compensatory pattern of movement to reduce the quadriceps demand during stair climbing in patients with more severe knee OA by increasing forward trunk lean. Assessing forward trunk lean during stair climbing may be a useful functional marker for evaluating osteoarthritis status and quadriceps function that appears to be a more sensitive indicator of disease severity than perceived pain. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:325–329, 2009     

Longitudinal Changes in the Total Knee Joint Moment After Anterior Cruciate Ligament Reconstruction Correlate With Cartilage Thickness Changes

This study investigated associations between changes in the total joint moment (TJM) at the knee and changes in cartilage thickness after anterior cruciate ligament reconstruction (ACLR). Seventeen subjects (five males; age: 29.6 ± 7.3 years) with unilateral ACLR underwent gait analysis and magnetic resonance imaging at baseline (2.2 ± 0.3 years post‐ACLR) and at long‐term follow‐up (7.7 ± 0.7 years post‐ACLR). Knee loading was assessed using the TJM, and differences in loading were analyzed using repeated measures analysis of variance. Pearson correlation coefficients assessed associations between changes in TJM and changes in (medial‐to‐lateral) M/L femoral cartilage thickness ratios in the ACLR limb. Bilaterally, there was no significant change in the magnitude of the TJM first peak (TJM1), however, there was a significant increase in the percent contribution of the knee flexion moment (KFM) (p < 0.001) and decrease in the percent contribution of the knee adduction moment (KAM) to TJM1 (p < 0.001). The change in the percent contributions of KFM and KAM to TJM1 were associated with changes in M/L femoral cartilage thickness in the ACLR limb. Specifically, subjects with smaller increases in KFM contribution (R = 0.521, p = 0.032) and smaller decreases in KAM contribution (R = ?0.521, p = 0.032) had a reduction in the M/L ratio in the central femoral subregion over the follow‐up period, with similar trends in the external femoral subregion. The study results provide new insight into changes in the loading environment at the knee joint prospectively following ACL reconstruction and give evidence that there are modifiable gait metrics that are associated with cartilage changes after ACLR. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1546–1554, 2019.     

Peer Reviewed: Chronic Disease Risk Factors Among Alaska Native and American Indian People,Alaska, 2004-2006

Introduction

The Alaska Education and Research Towards Health (EARTH) Study is being conducted to determine the prevalence of clinically measured chronic disease risk factors in a large population of American Indian/Alaska Native people (AI/AN). We report these estimates and compare them with those for the overall US population, as assessed by the National Health and Nutrition Examination Survey (NHANES).

Methods

We measured blood pressure, height, weight, and fasting serum lipids and glucose in a prospective cohort of 3,822 AI/AN participants who resided in Alaska during 2004 through 2006. We categorized participants as having chronic disease risk factors if their measurements exceeded cutoffs that were determined on the basis of national recommendations. We analyzed the prevalence of risk factors by sex and age and compared the age-adjusted prevalence with 1999-2004 NHANES measurements.

Results

EARTH participants were significantly more likely than NHANES participants to be overweight or obese and to have impaired fasting glucose, low high-density lipoprotein cholesterol, high low-density lipoprotein cholesterol, and hypertension. The prevalence of high total cholesterol and triglycerides was not significantly different between the 2 study populations.

Conclusion

We provide baseline clinical measurements for chronic disease risk factors for a larger study sample than any previous study of AI/AN living in Alaska. The prevalence of most risk factors measured exceeded national rates. These data can be used to tailor health interventions and reduce health disparities.     

Strategies for Successful Retention of Alaska Native and American Indian Study Participants

This paper reports the strategies used to track and follow 3,828 Alaska Native and American Indian study participants in the city of Anchorage and more rural areas of Alaska and provides characteristics of respondents and non-respondents. Over 88% were successfully followed-up, with 49% of respondents completed in three or fewer attempts. Follow-up completion rates were significantly higher for women, those living in a rural area, over age 55, married, employed, having a higher household income, and at current residence for more than five years. Follow-up of large numbers of Alaska Native and American Indian people living in geographically diverse areas is feasible, although challenging. Successful strategies to avoid attrition include using telephones as the primary method of contact; using a computerized contact relationship management system to track efforts and manage data; obtaining contact information from participant contact networks, medical records, and community networks; using local village interviewers to contact participants without telephone service; and mailing paper questionnaires to participants who are incarcerated or use social services.     

Sensitivity of gait parameters to the effects of anti-inflammatory and opioid treatments in knee osteoarthritis patients

The study aim was to address the need for objective markers of pain-modifying interventions by testing the hypothesis that selective gait measures of knee joint loading can distinguish differences between non-steroidal anti-inflammatory (NSAID), analgesic treatment (opioid-receptor agonist), and placebo in patients medial knee osteoarthritis (OA). A randomized, single-blind washout, double-blind treatment, double-dummy cross-over trial using three treatment arms placebo, opioid (Oxycodone), and NSAID (Celecoxib) in medial compartment knee OA patients. Six patients with Kellgren-Lawrence radiographic severity grades of 2 or 3 completed six testing sessions (gait and pain assessment) at 2-week intervals. A significant increase was found in the knee total reaction moment and vertical ground reaction force (GRF) for Celecoxib compared to placebo (p=0.005, p=0.003), but not for Oxycodone compared to placebo (p=0.20, p=0.27) treatments. Walking speed was significantly higher for the Celecoxib and Oxycodone compared to placebo treatment (p=0.041 and p=0.031, respectively). Self-reported function (WOMAC scores) was not different among treatments (p>0.05). The changes in total reaction moments and GRFs for only the NSAID suggest that greater increases in joint loading occurs when joint inflammation is treated in addition to pain. The total knee reaction moment, representing the magnitude of the extrinsic moment, appears to be a sensitive marker, more so than self-reported metrics, for evaluating knee OA treatment effects.