Slower walking speed may be a marker for incident knee osteoarthritis (OA), say authors of an article published online last month in Arthritis Care & Research.
For this study, 1,858 noninstitutionalized residents age 45 years or older who lived at least 1 year in 1 of 6 townships in Johnston County, North Carolina, completed questionnaires and clinical examinations at baseline and at follow-up testing. Walking time was assessed using a manual stopwatch in 2 trials over an 8-foot distance. Walking speed was calculated as the average of both trials. For the hip and knee, researchers examined 3 outcomes per joint site—radiographic OA (weight-bearing anteroposterior knee radiographs, supine anteroposterior pelvic radiographs of the hip), chronic joint symptom, and symptomatic OA. Covariates included age, gender, race, education, marital status, body mass index, number of prescriptions, depressive symptoms, self-rated health, number of lower-body functional limitations, smoking, physical activity, and number of self-reported, health care provider-diagnosed chronic conditions.
Faster walking speed was consistently associated with lower incidence of radiographic (adjusted odds ratio [aOR]=0.88) and symptomatic knee OA (aOR=0.84). Slower walking speed was associated with greater incidence of these outcomes across a broad range of different clinical and radiographic OA outcomes.
APTA member Jama L. Purser, PT, PhD, is lead author of the study. APTA member Yvonne M. Golightly PT, PhD, is coauthor.
Blog Written by: Jeffrey Driban
Reviewed by: Stephen Thomas
Predictors of Radiographic Knee Osteoarthritis After Anterior Cruciate Ligament Reconstruction.
Li RT, Lorenz S, Xu Y, Harner CD, Fu FH, Irrgang JJ. Am J Sports Med. 2011 Oct 21. [Epub ahead of print]
http://www.ncbi.nlm.nih.gov/pubmed/22021585 (link to abstract)
Over the past few months, SMR had several posts highlighting that individuals with a history of knee injury are at greater risk for knee osteoarthritis (OA) even if they undergo surgeries like anterior cruciate ligament (ACL) reconstructions (see below). As clinicians we must strive to reduce the risk of knee OA for our injured patients. Unfortunately, it is unclear which variables might predict individuals who will develop knee OA after an injury. Therefore, Li et al. tried to determine the prevalence of knee OA after a single-bundle ACL reconstruction and to identify factors that predict the development of knee OA. This study was a secondary analysis derived from a study that assessed outcomes among 422 patients that underwent a single-bundle ACL reconstruction (Kowalchuk et al 2009). The current study focused on 249 patients that were entered in a research database and had physical examination and radiographic data. All of the ACL reconstructions were performed by one of two surgeons using the same surgical method. One orthopaedic surgeon scored the radiographic knee OA severity in medial and lateral tibiofemoral compartments as well as patellofemoral joints. The authors evaluated numerous potential risk factors: 1) patient characteristics (e.g., age, sex, body mass index [BMI], occupation), 2) surgical variables (e.g., concurrent meniscal tears, chondral lesions, graft type/placement), and 3) other factors (e.g., length of time between injury and surgery, length of follow-up time, need for revision surgery). The average time between surgery and follow-up was 7.9 years (range: 2.1 to 20.3 years) and on average patients were 26.4 years of age at the time of surgery. Between 25% and 32% of participants had radiographic evidence of knee OA in the medial or lateral tibiofemoral compartment or patellofemoral joint. In the final statistical models, four predictors were associated with increased odds of developing knee OA: pre-operative high BMI, medial chondral lesions, concurrent medial meniscectomy, and length of follow-up. Overall, predicting knee OA development based on these four predictors had a sensitivity of 60.2% (chance of positively diagnosing a patient who has pathology) and a specificity of 70.4% (chance of correctly identifying a healthy patient).