(1) Background: Both long and short sleep durations have been associated with negative health outcomes, particularly in middle-aged and older adults. To date, there has been little research on the association between sleep and osteoarthritis. This study aimed to evaluate the relationship between sleep duration and radiographically confirmed osteoarthritis in middle-aged and older women. (2) Methods: This study included 5268 women aged ≥50 years from the Korea National Health and Nutrition Examination Survey. Sleep duration was categorized into four groups (≤5 h, 6 h, 7–8 h, and ≥9 h) using responses from a self-reported questionnaire, and 7–8 h was set as an appropriate sleep duration. Osteoarthritis was defined as Kellgren–Lawrence grade ≥2 in the knee or hip area in radiographic images with knee or hip joint pain. The odds ratios (ORs) and 95% confidence intervals (CIs) of osteoarthritis according to sleep duration were calculated using multiple logistic regression analyses. (3) Results: The prevalence of osteoarthritis according to sleep duration showed a U-shaped curve, with the nadir in the appropriate sleep category (7–8 h). Compared with the 7–8 h sleep duration, the ORs (95% CIs) of osteoarthritis in the short sleep duration (≤5 h/day) and long sleep duration (≥9 h/day) were 1.343 (1.072–1.682) and 1.388 (1.020–1.889), respectively, after adjusting for age, body mass index, current smoking, alcohol consumption, regular exercise, occupation, residential area, hypertension, type 2 diabetes, cardiovascular disease, and stroke. (4) Conclusions: Short and long sleep duration were positively associated with osteoarthritis in middle-aged and older women.

The objectives of this study are to evaluate the contributions of the popliteofibular ligament (PFL), the popliteus tendon (PT), and the lateral (fibular) collateral ligament (LCL) to the posterolateral stability of the knee by changing the sequence of selective transection. Twelve fresh‐frozen cadaveric knees were divided into two groups. Group 1 has a cutting sequence as follows: PFL, PT, LCL. Group 2 has a cutting sequence as follows: PT, PFL, LCL. Each specimen was mounted on the apparatuses using the Ilizarov external fixator for measuring external rotatory and varus laxities at every 30° from 0° to 90° of knee flexion. In both groups, there was no significant difference between the PFL and PT in the increment of respective external rotatory laxity after transection at each knee flexion angle, except 0° in group 2. The transection of the LCL significantly increased the external rotation laxity at 0° and 30°. Varus instability was increased significantly only after cutting the LCL at every knee flexion angle. In conclusion, both the PFL and PT equally contribute to the external rotatory stability. The LCL also contributes to the external rotatory stability at early range of knee flexion. The LCL is a main structure for varus stability in the knee. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1371–1376, 2008