Table 6.
Spearman’s rank correlations between patient-reported outcomes, function and key patellofemoral alignment measures
| 3D measures (weightbearing) | 2D measures (nonweightbearing) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Proximal translation | Lateral translation | Mediolateral tilt | Insall Salvati Ratio | Bisect offset | Patellar tilt angle | |||||||
| r | P | r | P | r | P | r | P | r | P | r | P | |
| Patient-reported outcomes | ||||||||||||
| KOOS (n=15)† | ||||||||||||
| Symptoms | −0.24 | 0.39 | −0.45 | 0.09 | −0.34 | 0.22 | 0.23 | 0.41 | −0.43 | 0.11 | −0.48 | 0.07 |
| Pain | −0.63 | 0.01 | −0.31 | 0.27 | −0.35 | 0.20 | −0.03 | 0.93 | −0.15 | 0.60 | −0.11 | 0.68 |
| Activities of Daily Living | −0.49 | 0.06 | −0.22 | 0.41 | −0.28 | 0.31 | 0.15 | 0.59 | −0.03 | 0.93 | −0.24 | 0.40 |
| Sport and Recreation | −0.38 | 0.16 | −0.39 | 0.16 | −0.40 | 0.14 | −0.11 | 0.70 | −0.37 | 0.18 | −0.36 | 0.18 |
| Quality of Life | −0.20 | 0.47 | −0.63 | 0.01 | −0.52 | 0.05 | −0.01 | 0.98 | −0.57 | 0.03 | −0.65 | <0.01 |
| Patellofemoral | −0.41 | 0.13 | −0.28 | 0.31 | −0.23 | 0.42 | −0.08 | 0.77 | −0.24 | 0.40 | −0.30 | 0.27 |
| AKPS (n=15) | −0.58 | 0.02 | −0.41 | 0.13 | −0.50 | 0.06 | 0.09 | 0.75 | −0.30 | 0.28 | −0.36 | 0.19 |
| Tampa Scale for Kinesiophobia (n=15) | 0.21 | 0.44 | −0.01 | 0.98 | 0.08 | 0.77 | 0.19 | 0.49 | −0.22 | 0.42 | −0.26 | 0.36 |
| Knee Self-Efficacy Scale (n=15) | ||||||||||||
| Daily Activities | −0.69 | <0.01 | −0.20 | 0.47 | −0.34 | 0.22 | −0.22 | 0.44 | −0.10 | 0.72 | 0.01 | 0.98 |
| Sport & Leisure | −0.49 | 0.06 | 0.03 | 0.91 | −0.01 | 0.97 | 0.09 | 0.75 | 0.26 | 0.35 | 0.13 | 0.65 |
| Physical Activities | −0.48 | 0.07 | −0.39 | 0.15 | −0.45 | 0.09 | −0.06 | 0.83 | −0.19 | 0.49 | −0.16 | 0.57 |
| Knee Function in the Future | −0.20 | 0.47 | −0.20 | 0.48 | −0.28 | 0.32 | 0.38 | 0.16 | 0.05 | 0.85 | 0.03 | 0.93 |
| EQ-5D-5L (n=30) | −0.37 | 0.04 | 0.02 | 0.93 | −0.31 | 0.10 | −0.42 | 0.02 | −0.49 | <0.01 | −0.35 | 0.06 |
| Functional performance (n=30) | ||||||||||||
| 30 s chair stand test | −0.19 | 0.31 | −0.02 | 0.94 | 0.09 | 0.63 | −0.04 | 0.85 | 0.16 | 0.39 | 0.08 | 0.68 |
| Repetitive single leg rises | −0.48 | <0.01 | −0.07 | 0.72 | −0.18 | 0.34 | −0.32 | 0.09 | −0.24 | 0.21 | −0.22 | 0.24 |
| Timed 12 stair climb | −0.48 | <0.01 | 0.16 | 0.41 | −0.15 | 0.43 | −0.33 | 0.07 | −0.03 | 0.88 | 0.06 | 0.77 |
†Only participants with patellofemoral osteoarthritis completed knee-related patient-reported outcomes (n=15); all remaining comparisons are for the full sample (n=30).
Items in bold indicate moderate correlation (r ≥0.40), or statistical significance (p≤0.05).
Correlation signs have all been standardised to reflect that a ‘–’ sign indicates that as the patella moves further into malalignment (ie, more proximally, more laterally, or more lateral tilt), the outcome of interest worsens.
AKPS, Anterior Knee Pain Scale; EQ-5D-5L, Euro-Quality of Life 5-Dimension, 5-Likert scale; KOOS, Knee injury and Osteoarthritis Outcome Score; PFOA, Patellofemoral osteoarthritis.