Comparison of Patient-Reported Outcomes and Functional Assessment Using a Marker-Less Image Capture System in End-Stage Knee Arthritis

Do Patient Reported Outcomes Reflect Objective Measures of Function? Implications for Total Knee Arthroplasty

BACKGROUND

Patient Reported Outcomes (PROs) are used in research, clinical practice, and by federal reimbursement models to assess outcomes for patients who have knee osteoarthritis (OA) and total knee arthroplasty (TKA). We examined a large cohort of patients to determine if commonly used PROs reflect observed evaluation as measured by standardized functional tests (SFTs).

METHODS

We used data from the Osteoarthritis Initiative, a ten-year observational study of knee osteoarthritis patients. Two cohorts were examined: 1) participants who received TKA (n=281) and 2) participants who have native OA (n=4,687). The PROs included Western Ontario and McMaster Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), 12-Item Short Form Health Survey (SF-12), and Intermittent and Constant Pain Score (ICOAP). The SFTs included 20 and 400 meter (M) walks and chair stand pace. Repeated measures correlation coefficients were used to determine the relationship between PROs and SFTs.

RESULTS

The PROs and SFTs were not strongly correlated in either cohort. The magnitude of the repeated measures correlation (r_rm) between KOOS, WOMAC, SF-12, and ICOAP scores and SFT measurements in native knee OA patients ranged as follows: 400 M walk pace (0.08 to 0.20), chair stand pace (0.05 to 0.12), and 20 M pace (0.02 to 0.21), all with P<0.05. In the TKA cohort, values ranged as follows: 400 M walk pace (0.00 to 0.29), chair stand time (0.02 to 0.23), and 20 M pace (0.03 to 0.30). Due to the smaller cohort size, the majority, but not all had P values <0.05.

CONCLUSION

There is not a strong association between PROs and SFTs among patients who have knee OA or among patients who received a TKA. Therefore, PROs should not be used as a simple proxy for observed evaluation of physical function. Rather, PROs and SFTs are complementary and should be used in combination for a more nuanced and complete characterization of outcome.

Assessment of Bilateral Shoulder Range of Motion in Firefighter Trainees Using a Markerless Motion Capture System

The unpredictable environments firefighters face paired with biomechanically compromising shoulder movements, such as overhead and lifting movements, place this population at an increased risk for shoulder injury. The purpose of this study was to assess firefighter trainees’ bilateral shoulder range of motion (ROM) using the Dynamic Athletic Research Institute Motion system. Retrospective anthropometric and ROM data for 31 male firefighter trainees were analyzed. Firefighter trainees’ mean shoulder ROM for bilateral external rotation, internal rotation, and extension were lower than previously published values. External rotation demonstrated the lowest percentage of trainees within normal ROM (left—6.67%, right—16.67%). Noting the susceptibility of upper extremity injuries among firefighters, establishing baseline ROM measurements for reference may improve musculoskeletal evaluations, training interventions, and injury rehabilitation.

Active range of motion of the shoulder: a cross-sectional study of 6635 subjects

Background

Normative data for passive range of motion are well established, but daily living is comprised of active motion. The purpose of this study was to establish normative values for active range of motion of the shoulder across age, sex, and arm. Our hypotheses were that active range of motion of the shoulder (1) decreases with age group, (2) differs between males and females, and (3) differs between the right arm and left arm.

Methods

Shoulder active range of motion was captured with an eight-camera markerless motion capture system. Data were collected for a heterogenous sample of 6635 males and females of all ages. For each subject, 6 shoulder motions were collected with maximum values measured: external rotation, internal rotation, flexion, extension, abduction, and horizontal abduction. Three-way repeated measures analyses were performed, with 2 between-subject factors (age group and sex) and 1 within-subject factor (arm). The unadjusted threshold for statistical significance was α = 0.05.

Results

External rotation decreased with age (approximately 10° decrease from below 30 years to above 60 years). External rotation was approximately 5° greater in the right arm, whereas internal rotation was approximately 5° greater in the left arm. Flexion decreased with age (approximately 15° decrease from below 20 years to above 60 years). For age groups from 10 to 59 years, extension and horizontal abduction were approximately 5° to 10° greater in females than males. Abduction was greater for females than males. Abduction was also greater in younger people (aged 10-29 years) than older people.

Conclusion

In general, active range of motion of the shoulder decreases with age. Sex (male/female) and arm side (right/left) also influence shoulder range of motion.