ACR2012 Highlights: Predictors of Osteoarthritis Outcome

Among presentations on OA at last month’s American College of Rheumatology meeting, several described ways of identifying or predicting disease status and progression-through imaging, clinical features, and biochemical markers. (Click on hyperlinks below to read abstracts of the presentations.)
 

•  The Ober test for iliotibial (IT) band tightness as well as measures of gait speed and aerobic capacity can assess the severity of knee ostearthritis adequately, and more cost-effectively than radiographic studies. Aiming to offer a "rich clinical description of patients" with knee OA and identify the most efficient exam procedures for defining disease status, Harvard and Tufts researchers analyzed baseline data from 47 patients with knee OA recruited for a randomized clinical trial. Although presenting symptoms varied widely, those with IT band tightness had the most pain and physical dysfunction. (Abstract #798)

•  Thirteen clinical features are significantly associated with progression of knee osteoarthritis, according to analysis of data from the Osteoarthritis Initiative by researchers at the University of Maryland. These are: knee joint effusion, pain on flexion, patellofemoral crepitus, patellar grind, and flexion contracture, number of hand bony enlargements, history of knee injury, and use of analgesics, repeated chair stand pace, 400-meter walk pace, and pain during 400-meter walk; Knee Injury and Osteoarthritis Outcome Score (KOOS) sports and recreational activities score and KOOS symptoms score. (Abstract #912) 

•  The location and growth of bone marrow lesions offer insights into the severity of osteoarthritis, judging from two separate studies. In one of these, a multicenter team assessed bone marrow lesions among patients in the Osteoarthritis Initiative who had total knee replacement. Large lesions in the medial femur and/or tibia, but not in the patellofemoral joint, were associated with need for knee replacement, as were lesions that grew in any of the subregions of the medial tibiofemoral compartment. (Abstract #249). In the other study (Abstract #2512), changes in the volume of lesions were associated with severity of knee pain.

•  Changes in subchondral bone area discriminate significantly between arthritic knees and healthy knees, and offer a useful tool for monitoring progression. This is the conclusion of researchers from the UK who analyzed MRI images taken from 933 patients in the Osteoarthritis Initiative at baseline and annually up to four years. Discrimination was strongest in the medial compartments, they found, particularly the femur. Changes within the patellofemoral joint distinguished between normal and arthritic knees as strongly as in the femorotibial joint. (Abstract #732).

•  Two biomarkers in synovial fluid may ultimately prove useful in monitoring progression. A team from Brigham and Women's Hospital in Boston and from Thermo Fischer Scientific have found that the synovial proteins clusterin (which removes debris) and lubricin (which reduces wear in cartilage) both correlate with joint space narrowing over the course of 30 months. (Abstract #735)

•  MRI changes in the knee joint also offer reliable detection of structural progression. In yet another insight from the Osteoarthritis Initiative, loss of longitudinal cartilage thickness and structural progression measured by MRI predicted the need for knee replacement. This may support treatments that slow or prevent cartilage loss as a way to avoid or delay surgery, say the researchers. (Abstract #2470)

• The Harris Hip Score adequately distinguishes good responders and nonresponders to total hip arthroplasty, rheumatologists from Rush University Medical Center find from a retrospective study of 132 patients. Oddly, some people with better preoperative function had poorer outcomes. (Abstract #797)