Patient-Reported Outcome Measures for Adults and Adolescents With Patellofemoral Pain: A Systematic Review of Construct Validity, Reliability, Responsiveness, and Interpretability Using the COSMIN Methodology

Males with patellofemoral pain have altered movements during step-down and single-leg squatting tasks compared to asymptomatic males: A cross-sectional study

Background and Aims

Patellofemoral pain (PFP) is common in males, causing reduced physical activity and chronic pain. One proposed cause of PFP is aberrant biomechanics during tasks loading the patellofemoral joint. Consistent evidence exists for females with PFP, but it is uncertain if males with PFP have altered biomechanics. This study investigated the kinematics of males with PFP compared to pain-free males during forward step-down (StDn) and single-leg squat (SLSq).

Methods

A cross-sectional study including 40 males aged 20-39 years (28.28 ± 5.46) was conducted (20 PFP, 20 pain-free). Participants performed StDn and SLSq while motion was captured with a video-based motion capture system (Motion Analysis Corporation). Triplanar peak angles and angular ranges of motion (ROM) of the trunk, pelvis, and weight-bearing hip, knee, and ankle were dependent variables. Mixed-model ANOVA tests were used to determine the presence of significant interactions and main effects of group and task.

Results

Males with PFP had significantly lower peak knee adduction angles compared to pain-free males (p = 0.01). Significant group x task interactions were found for hip and pelvis ROM (p < 0.05). PFP participants had increased hip and pelvis ROM during StDn in the frontal and transverse planes but reduced or nearly equal ROM for these variables during SLSq. Peak hip adduction, hip internal rotation, contralateral pelvic drop and anterior tilt, trunk flexion, and ankle dorsiflexion were greater during StDn compared to SLSq (p < 0.05). ROM of the hip, pelvis, trunk, and ankle were greater during StDn compared to SLSq (p < 0.05).

Conclusion

Males with PFP had reduced peak knee adduction angles in StDn and SLSq. Males with PFP demonstrated increased hip and pelvis ROM during StDn versus SLSq, particularly in the frontal and transverse planes. Clinicians should consider StDn as a clinical test since aberrant movement may be easier to detect than in SLSq.

Reliability and validity of the Turkish version of the patellofemoral pain and osteoarthritis subscale of the KOOS

BACKGROUND

Patellofemoral pain and patellofemoral osteoarthritis are highly prevalent knee disorders associated with pain and functional limitations. The subscale of the Knee Injury and Osteoarthritis Outcome Score for patellofemoral pain and osteoarthritis (KOOS-PF) was developed to evaluate patients with patellofemoral pain and osteoarthritis.

PURPOSE

This study aims to translate the KOOS-PF into Turkish and assess its measurement properties.

METHODS

The Turkish version of the KOOS-PF was tested for reliability and validity in a convenience sample of 55 patients with patellofemoral pain and/or osteoarthritis. Reliability analyses were conducted through a retest 7-14 days later with a subgroup of 35 patients. The KOOS-PF was compared with Kujala's Anterior Pain Scale (AKPS) and the Short Form-36 health survey (SF-36) to assess construct validity. Additionally, responsiveness analyses were performed on 29 patients who were followed up with a home-based exercise program three months later.

RESULTS

The Turkish version of KOOS-PF has high test-retest reliability (ICC2,1 = 0.96) and internal consistency (Cronbach's α = 0.91). It has a very good correlation with the AKPS (r = 0.77) and the SF-36 physical component summary (r = 0.64) with no floor or ceiling effects. Responsiveness is confirmed by a good correlation with the global rating of change score (r = 0.51). The minimal clinically important change is 16.5 points, and the minimal important difference is 10.2.

CONCLUSION

The Turkish version of the KOOS-PF is valid, reliable, and responsive for evaluating patients with patellofemoral pain and/or osteoarthritis.