Multidomain gait and inter-limb asymmetry measures discriminate early knee osteoarthritis prior to radiographic change.

To assess whether knee extensor strength or hamstring:quadriceps (H:Q) ratio predicts risk for incident radiographic tibiofemoral and incident symptomatic whole knee osteoarthritis (OA) in adults ages 50-79 years. We followed 1,617 participants (2,519 knees) who, at the baseline visit of the Multicenter Osteoarthritis (MOST) Study, did not have radiographic tibiofemoral OA and 2,078 participants (3,392 knees) who did not have symptomatic whole knee OA (i.e., did not have the combination of radiographic OA and frequent knee symptoms). Isokinetic strength was measured at baseline, and participants were followed for development of incident radiographic tibiofemoral OA, or incident symptomatic whole knee OA at 30 months. Generalized estimating equations accounted for 2 knees per subject, and multivariable models adjusted for age, body mass index (BMI), hip bone mineral density, knee surgery or pain, and physical activity score. In the studies of incident radiographic and incident symptomatic knee OA, mean +/- SD ages were 62.4 +/- 8.0 years and 62.3 +/- 8.0 years, respectively, and mean +/- SD BMI scores were 30.6 +/- 5.8 kg/m(2) and 30.2 +/- 5.5 kg/m(2), respectively. Knee extensor strength and H:Q ratio at baseline significantly differed between men and women. Neither knee extensor strength nor the H:Q ratio was predictive of incident radiographic tibiofemoral OA. Compared with the lowest tertile, the highest tertile of knee extensor strength protected against development of incident symptomatic whole knee OA in both sexes (adjusted odds ratio 0.5-0.6). H:Q ratio was not predictive of incident symptomatic whole knee OA in either sex. Thigh muscle strength does not appear to predict incident radiographic OA, but does seem to predict incident symptomatic knee OA.

Knee symptom but not radiographic knee osteoarthritis increases the risk of falls and fractures: results from the Osteoarthritis Initiative

THU0487 Prolonged Symptom Elevation but not Progression Following Incident Radiographic Knee Osteoarthritis: Data from the Osteoarthritis Initiative

Background: The long-term prevalence of knee osteoarthritis (OA) after anterior cruciate ligament (ACL) injury is unknown, especially in patients without a history of ACL surgery. Purpose: To (1) describe the prevalence of radiographic OA, symptomatic OA, and knee replacement surgery 32 to 37 years after acute ACL injury and to (2) compare the prevalence of radiographic OA, symptomatic OA, and knee symptoms between patients allocated to early ACL surgery or no ACL surgery and patients who crossed over to ACL surgery. Study Design: Cohort study; Level of evidence, 2. Methods: Participants aged 15 to 40 years at the time of ACL injury were allocated to surgical (augmented or nonaugmented ACL repair) or nonsurgical ACL treatment within 14 days of injury. At 32 to 37 years after the initial injury, 153 participants were followed up with plain weightbearing radiographs and completed 4 subscales from the Knee injury and Osteoarthritis Outcome Score (KOOS). Radiographic OA was defined as Kellgren and Lawrence grade 2 or higher. Symptomatic OA was defined as radiographic OA plus knee symptoms measured with the KOOS. Results: Participants allocated to ACL surgery (n = 64) underwent surgery at a mean ± SD of 5 ± 4 days (range, 0-11 days) after injury. Of the 89 participants allocated to no ACL surgery, 53 remained nonsurgically treated, 27 had ACL surgery within 2 years, and 9 had ACL surgery between 3 and 21 years after injury. In the total sample, 95 participants (62%) had radiographic tibiofemoral OA, including 11 (7%) who had knee replacement. The prevalence of radiographic tibiofemoral OA was lower in the group allocated to ACL surgery compared with the group who never had ACL surgery (50% vs 75%; P = .005). The prevalence of symptomatic OA (50% in the total sample) and patellofemoral radiographic OA (35% in the total sample) was similar between groups. Conclusion: Patients allocated to early ACL surgery, performed a mean 5 days after injury, had a lower prevalence of tibiofemoral radiographic OA at 32 to 37 years after injury compared with patients who never had ACL surgery. The prevalences of symptomatic OA, radiographic patellofemoral OA, and knee symptoms were similar irrespective of ACL treatment. Overall, the prevalence of OA after ACL injury was high. Registration: NCT03182647 (ClinicalTrials.gov identifier)

Background: Multiple sclerosis (MS) causes an asymmetric pattern in the strength of the muscles on both sides of the body. So far, the amount of asymmetry in the isometric strength of knee muscles in Iranian women with MS has not been studied. Therefore, this study aimed to investigate the extent of bilateral asymmetry in the isometric strength of knee flexor and extensor muscles in Iranian women with MS. Materials and Methods: This is a causal-comparative study. From 93 MS patients, 27 females (20-50 years with an expanded disability status scale of less than 4) were selected as the statistical sample. Maximal voluntary isometric contraction (MVIC) of the knee flexor and extensor muscles was measured at the angles of 20 and 70 degrees using a Biodex isokinetic dynamometer. The asymmetric score in muscle strength was also calculated as a percentage of the ratio between the peak torque isometric strength in the muscles of the weak leg to the strong one. The data were analyzed using the correlated t-test at the 95% confidence level. Results: The results showed a significant difference in MVIC of the knee extensor and flexor muscles between the strong and the weak leg at the angles of 20 and 70 degrees in the statistical sample of the present study (P=0.001). Additionally, in terms of asymmetry in strength, the results showed that the highest percentage of bilateral asymmetry between strong and weak legs was in the strength of knee extensor muscle at the angle of 20 degrees (31.2%), and the lowest percentage was in knee flexor muscles at 70 degrees (16.1%). Conclusion: The results of this study showed that the asymmetric rate in the strength of flexor and extensor muscles of the strong and weak leg is about 16% to 31% in Iranian women with MS with an expanded disability status scale of less than 4.

Study Design Clinical measurement, cross-sectional. Background Individuals who have undergone anterior cruciate ligament (ACL) reconstruction commonly experience long-term impairments in quality of life (QoL), which may be related to persistent knee symptoms or radiographic osteoarthritis (ROA). Understanding the impact of knee symptoms and ROA on QoL after ACL reconstruction may assist in the development of appropriate management strategies. Objectives To (1) compare QoL between groups of individuals after ACL reconstruction (including those who are symptomatic with ROA, symptomatic without ROA, and asymptomatic [unknown ROA status]), and (2) identify specific aspects of QoL impairment in symptomatic individuals with and without ROA post ACL reconstruction. Methods One hundred thirteen participants completed QoL measures (Knee injury and Osteoarthritis Outcome Score QoL subscale [KOOS-QoL], Anterior Cruciate Ligament Quality of Life [ACL-QoL], Assessment of Quality of Life-8 Dimensions [AQoL-8D]) 5 to 20 years after ACL reconstruction. Eighty-one symptomatic individuals underwent radiographs, and 32 asymptomatic individuals formed a comparison group. Radiographic osteoarthritis was defined as a Kellgren-Lawrence grade of 2 or greater for the tibiofemoral and/or patellofemoral joints. Mann-Whitney U tests compared outcomes between groups. Individual ACL-QoL items were used to explore specific aspects of QoL. Results In symptomatic individuals after ACL reconstruction, ROA was related to worse knee-related outcomes on the KOOS-QoL (median, 50; interquartile range [IQR], 38-69 versus median, 69; IQR, 56-81; P<.001) and the ACL-QoL (median, 51; IQR, 38-71 versus median, 66; IQR, 50-82; P = .04). The AQoL-8D scores showed that health-related QoL was impaired in both symptomatic groups compared to the asymptomatic group. The ACL-QoL item scores revealed greater limitations and concern surrounding sport and exercise and social/emotional difficulties in the symptomatic group with ROA. Conclusion Osteoarthritis is associated with worse knee-related QoL in symptomatic individuals after ACL reconstruction. Diagnosing ROA in symptomatic individuals after ACL reconstruction may be valuable, because these individuals may require unique management. Targeted strategies to facilitate participation in satisfying activities have potential to improve QoL in symptomatic people with ROA after ACL reconstruction. J Orthop Sports Phys Ther 2018;48(5):398-408. doi:10.2519/jospt.2018.7830.

Bone mineral density and osteoarthritis: Data from the Baltimore Longitudinal Study of Aging

To investigate long-term radiographic and patient-relevant outcome of isolated limited meniscectomy with regard to type of meniscal tear and extent of surgical resection. We studied 155 patients with intact cruciate ligaments (mean +/- SD age 54 +/- 12 years) who had undergone meniscectomy an average of 16 +/- 1 years earlier. The patients were examined using standardized radiography and validated self-administered questionnaires. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to quantify knee-related symptoms, and the definition of a symptomatic knee was determined. We used 68 control subjects matched for age, sex, and body mass index to calculate the relative risks (RRs). Radiographic tibiofemoral osteoarthritis (OA) (Kellgren/Lawrence grade > or =2) was present in 66 index knees (43%), of which 39 (59%) were considered to be symptomatic according to the KOOS. In total, 77 patients (50%) had a symptomatic index knee. In a multivariate model, degenerative meniscal tears were associated with both radiographic OA (P = 0.030) and combined radiographic and symptomatic OA (P < or = 0.015). The RRs for combined radiographic and symptomatic OA after degenerative and traumatic types of meniscal tear were 7.0 (95% confidence interval [95% CI] 2.1-23.5) and 2.7 (95% CI 0.9-7.7), respectively, compared with matched controls. An isolated meniscal tear treated by limited meniscectomy is associated with a high risk of radiographic and symptomatic tibiofemoral OA at 16-year followup. Factors associated with worse outcome were degenerative meniscal lesions and extensive resections. We suggest that degenerative meniscal tears may be associated with incipient OA, and that the meniscal tear signals the first symptom of the disease.

The purpose of the present study was to investigate the influence of strength outcome [maximal voluntary contraction (MVC) torque vs. rate of torque development (RTD)], motor task (unilateral vs. bilateral) and muscle group (knee extensors vs. flexors) on the magnitude of bilateral deficits and inter-limb asymmetries in a large heterogeneous group of athletes. 259 professional/semi-professional athletes from different sports (86 women aged 21 ± 6years and 173 men aged 20 ± 5years) performed unilateral and bilateral "fast and hard" isometric maximal voluntary contractions of the knee extensors and flexors on a double-sensor dynamometer. Inter-limb asymmetries and bilateral deficits were compared across strength outcomes (MVC torque and multiple RTD measures), motor tasks and muscle groups. Most RTD outcomes showed greater bilateral deficits than MVC torque for knee extensors, but not for knee flexors. Most RTD outcomes, not MVC torque, showed higher bilateral deficits for knee extensors compared to knee flexors. For both muscle groups, all RTD measures resulted in higher inter-limb asymmetries than MVC torque, and most RTD measures resulted in greater inter-limb asymmetries during unilateral compared to bilateral motor tasks. The results of the present study highlight the importance of outcome measure, motor task and muscle group when assessing bilateral deficits and inter-limb asymmetries of maximal and explosive strength. Compared to MVC torque and bilateral tasks, RTD measures and unilateral tasks could be considered more sensitive for the assessment of bilateral deficits and inter-limb asymmetries in healthy professional/semi-professional athletes.

AB0976 Associations between ultrasonographic and radiographic features of osteoarthritis and pain – a within-person knee-matched case-control study

BackgroundStructural pathology may be present in joints without radiographic evidence of osteoarthritis (OA). Ultrasound is a sensitive tool for early detection of osteophytes. Our aim was to explore whether ultrasound-detected...

To describe the prevalence, incidence, and progression of radiographic thumb carpometacarpal (CMC-1) and trapezioscaphoid (TS) radiographic osteoarthritis (ROA) in the general Dutch population aged ≥55y. Data were from the first and second cohort of the Rotterdam Study (1990-2005, 4-12 years follow-up, age 55+). Participants underwent bilateral radiographs at baseline (N=7792) and follow-up (N=3804), read for Kellgren-Lawrence (K-L) grade. ROA was defined on the joint level as K-L grade ≥2. The prevalence was assessed at baseline, incidence at follow-up in those free of ROA at baseline, and progression in those with ROA. Differences based on sex and age were evaluated using logistic regression models. At baseline, 1977 (25.3%) had CMC-1 ROA and 1133 (14.5%) TS ROA. The prevalence was higher in females for CMC-1 (aOR=1.98 95%CI [1.77-2.21]) and TS ROA (aOR=2.00 [1.74-2.29]) and increased for every year of age (CMC-1 ROA 1.08 [1.07-1.08]) (TS ROA 1.06 [1.05-1.07]). Most (437/512; 85.4%) incident cases of CMC-1 ROA (2994at risk) were mild (K-L=2), whereas most (145/167; 86,8%) incident cases of TS ROA (3311at risk) were moderate to severe (K-L=3/4). CMC-1 ROA progression was mostly (88/100; 88.0%) seen in the K-L 2 group at baseline, whereas that was (4/17; 23.5%) for TS ROA. CMC-1 ROA and TS ROA are prevalent in the general Dutch population. While incident CMC-1 ROA was primarily mild, incident TS ROA was more often moderate to severe. CMC-1 ROA was a strong predictor for incident TS ROA.

Few risk factors for knee osteoarthritis (OA) are appreciated, and the discordance between symptoms and the severity of structural disease has not been explained. Knee height contributes to moments around the knee. The longer the leg, the more torque is present. Although this would suggest that having long legs would be related to the occurrence of knee OA and pain, this issue has not been studied. Our aim was to explore the association between knee height, knee pain, and knee OA. We recruited a random sample of Beijing residents ages 60 years and older. Subjects answered questions about joint symptoms, and radiographs of their knees were obtained. A knee joint with a Kellgren/Lawrence grade of >/=2 was defined as having radiographic OA. Patellofemoral OA was defined as being present when grade >/=1 osteophytes or grade >/=1 joint space narrowing was observed on skyline views of the patella or anterior femur. Subjects were considered to have symptomatic OA when both radiographic OA and self-reported pain were present in the same joint. Knee height was measured on the right leg using a sliding broad-blade caliper; the subject was seated, and the subject's feet were bare. We used logistic regression analyses to assess whether knee height was associated with prevalent radiographic and symptomatic OA. We then assessed whether knee height was associated with knee symptoms independently of structural change. A total of 1,006 men (mean +/- SD age 68.4 +/- 6.4 years) and 1,500 women (mean +/- SD age 67.5 +/- 6.1 years) participated in this study. Higher knee height was associated with an increasing prevalence of both radiographic and symptomatic OA, especially among women. For radiographic OA, the magnitude of association was similar for the patellofemoral and tibiofemoral compartments. Among women with knee pain, higher knee height was associated with more severe knee pain (P = 0.0004 for the highest quartile versus the lowest quartile of knee height) independently of the severity of radiographic OA. Knee height is associated with prevalent radiographic and symptomatic knee OA. It may also play an important role in knee symptoms. This study highlights the importance of mechanical forces in the determination of OA and knee symptoms.

The natural history of end-stage knee osteoarthritis: Data from the osteoarthritis initiative

THU0479 The Sex Ratios of Knee and Hip Osteoarthritis are Different in Korea: Data from the Korean National Health and Nutrition Examination Survey 2013