A Rich Description of Clinical Exam Features in Patients with Knee Osteoarthritis (KOA) and Their Correlation with Functional Outcomes

Abstract

Background: Imaging techniques (MRIs) provide a contextual description of cartilage and soft tissues. However, cost and poor correlation with knee osteoarthritis (KOA) symptoms lead to reliance on physical measures for clinical decision-making. There is limited literature on the association between examination procedures and reported KOA symptoms.  This study aims to: (1) provide a rich clinical description of patients with KOA (2) correlate examination findings with self-reported measures and (3) determine the most efficient exam procedures to classify disease severity.

Methods: 44 patients with KOA were enrolled from community and orthopedic clinics. Patients completed self-reported outcome surveys, completed performance tests (timed walk, repeated sit-to-stand, 6 m walk test), and received a physical examination by a physical therapist using a standardized reporting system.  The exam included an interview, leg length measurements, Range-of-motion, muscle strength testing, ligamentous stability tests, patella gliding, and functional activity assessments. Descriptive statistics and correlations were used to characterize the sample and determine associations between exam procedures, performance tests and outcome measures.

Results: Subject’s mean age was 58 years (SD=10), 52% were Caucasian and 38% were African American.  Patients exhibited limited function (mean WOMAC =132.1) and reduced gait speed (mean timed walk = 18.0s (SD=16.2) and exercise capacity (mean 6-minute walk= 392.16 m (SD=90).  Clinical measures of ligament stability and were moderately associated with KOA symptoms.

Conclusions: Patients with symptomatic KOA vary in clinical presentation and perceptions of functional limitations.  Specific clinical exam measures may help identify patients with more severe disease and are less costly than radiographic tests.