Background
Methods
Participants
Screening and baseline assessment
Follow up
Magnetic resonance imaging: acquisition and analysis
Radiographs
Statistical analysis
Results
Participants
Variable | MRI cohort | Radiograph cohort |
---|---|---|
Number | 120a
| 188 |
Age (years), mean (SD) | 62.3 (10.3) | 63.2 (10.3) |
Female, frequency (%) | 62 (51.7) | 97 (51.6) |
Number of days to follow-up appointment, median (IQR) | 8.0 (7.0–14.0) | 8.0 (7.0–14.0) |
KOOS-pain subscale score (0–100)b, median (IQR) | 44.4 (36.1–55.6) | 44.4 (36.1–55.6) |
Pain on nominated activity, VASNA (0–10 cm)c, median (IQR) | 7.0 (5.5–7.7)d
| 7.0 (5.6–8.1)e
|
Pain in last week, VAS (0–10 cm)c, median (IQR) | 6.5 (4.7–7.8)d
| 6.5 (4.9–8.0)e
|
Responders to injection, at follow-up visit, frequency, (%) | 85 (70.8) | 137 (72.9) |
Imaging characteristics
Maximal score | MRI features (WORMS) | Radiographic features | |||||||
---|---|---|---|---|---|---|---|---|---|
BML (n) | Menisci (n) | Effusion (n) | Synovitis (n) | Cartilage (n) | Osteophyte (n) | Attrition (n) | KLa (n) | JSNa (n) | |
0 | 5 | 35 | 22 | 0 | 5 | 0 | 3 | 0 | 3 |
1 | 30 | 0 | 46 | 2 | 5 | 1 | 19 | 0 | 59 |
2 | 26 | 9 | 32 | 18 | 9 | 10 | 49 | 69 | 90 |
2.5 | - | - | - | - | 10 | - | - | - | - |
3 | 48 | 24 | 9 | 89 | 8 | 19 | 38 | 101 | 35 |
4 | 41 | 26 | 25 | 18 | |||||
5 | 0 | 36 | 16 | ||||||
6 | 0 | 10 | 33 | ||||||
7 | 5 |
Structural parameters and change in pain
Predictor variable in regression | KOOS pain score | Pain on nominated activity VAS | ||||
---|---|---|---|---|---|---|
N
| b coefficient (95% CI)c
|
P value |
N
| b coefficient (95% CI)d
|
P value | |
MRI (WORMS) | ||||||
Synovitis maximal score (0–3) | 109 | -1.94 (-11.15 to 7.26) | 0.677 | 96 | 0.45 (-0.83 to 1.74) | 0.487 |
Bone marrow lesion maximal score (0–3) | 109 | -3.48 (-7.76 to 0.80) | 0.110 | 96 | 0.76 (0.16 to 1.36)* | 0.013 |
Bone attrition maximal score (0–3) | 109 | -1.78 (-6.98 to 3.42) | 0.498 | 96 | -0.07 (-0.81 to 0.66) | 0.846 |
Cartilage damage maximal score (0–6) | 109 | 0.09 (-2.55 to 2.72) | 0.948 | 96 | 0.16 (-0.20 to 0.53) | 0.378 |
Cyst maximal score (0–3) | 108 | 0.56 (-4.48 to 5.60) | 0.827 | 95 | 0.27 (-0.48 to 1.01) | 0.475 |
Menisci damage maximal score (0–6) | 109 | -2.12 (-4.49 to 0.25) | 0.079 | 96 | 0.37 (0.04 to 0.70)* | 0.027 |
Osteophyte maximal score (0–7) | 109 | 0.56 (-2.23 to 3.36) | 0.690 | 96 | 0.18 (-0.22 to 0.57) | 0.377 |
Synovial effusion (0–3) | 109 | -1.22 (-5.90, 3.46) | 0.608 | 96 | 0.17 (-0.49 to 0.83) | 0.606 |
MRI (quantitative) | ||||||
Synovial tissue volume (1000 mm3) | 111 | -0.05 (-0.67 to 0.57) | 0.883 | 98 | 0.03 (-0.05 to 0.12) | 0.408 |
Radiographs | ||||||
Tibiofemoral KL score (0–4) | 186 | -2.40 (-6.80 to 2.00) | 0.284 | 170 | 0.66 (0.02 to 1.30)* | 0.042 |
Patellofemoral KL score (0–4) | 187 | -0.001 (-3.16 to 3.16) | 0.999 | 171 | 0.64 (0.18 to 1.10)* | 0.006 |
Overall KL maximal scorea (0–4) | 187 | -1.97 (-6.64 to 2.71) | 0.408 | 171 | 0.94 (0.27 to 1.62)* | 0.007 |
Lateral tibiofemoral JSN score (0–3) | 185 | -0.001 (-4.12 to 4.12) | 1.000 | 169 | 0.05 (-0.56 to 0.67) | 0.865 |
Medial tibiofemoral JSN score (0–3) | 186 | -1.26 (-5.17 to 2.65) | 0.524 | 170 | 0.21 (-0.38 to 0.79) | 0.486 |
Patellofemoral JSN score (0–3) | 178 | -0.52 (-3.60 to 2.56) | 0.738 | 162 | 0.52 (0.06 to 0.98)* | 0.026 |
Overall JSN maximal scoreb (0–3) | 186 | -1.34 (-5.26 to 2.57) | 0.499 | 170 | 0.72 (0.14 to 1.29)* | 0.015 |
Knee mal-alignment angle (per degree) | 191 | 0.03 (-0.53 to 0.59) | 0.924 | 173 | -0.04 (-0.13 to 0.04) | 0.291 |
Predictors of responder status
Short term response
Predictor variable in regression | Short term responder at 2 weeks (yes/no) | Longer term responder at 6 months (yes/no) | ||||
---|---|---|---|---|---|---|
N
| Odds ratio (95% CI) |
P value |
N
| Odds ratio (95% CI) |
P value | |
MRI (WORMS) | ||||||
Synovitis maximal score (0–3) | 109 | 0.82 (0.32 to 2.13) | 0.689 | 109 | 0.43 (0.17 to 1.12) | 0.084 |
Bone marrow lesion maximal score (0–3) | 109 | 0.76 (0.49 to 1.19) | 0.231 | 109 | 1.12 (0.66 to 1.92) | 0.668 |
Bone attrition maximal score (0–3) | 109 | 0.94 (0.56 to 1.57) | 0.804 | 109 | 0.59 (0.32 to 1.10) | 0.097 |
Cartilage damage maximal score (0–6) | 109 | 0.98 (0.75 to 1.27) | 0.869 | 109 | 1.03 (0.74 to 1.42) | 0.873 |
Cyst maximal score (0–3) | 108 | 0.74 (0.46 to 1.20) | 0.222 | 108 | 1.27 (0.72 to 2.22) | 0.408 |
Menisci damage maximal score (0–6) | 109 | 0.95 (0.74 to 1.20) | 0.647 | 109 | 0.74 (0.55 to 0.98)* | 0.039 |
Osteophyte maximal score (0–7) | 109 | 1.13 (0.86 to 1.49) | 0.386 | 109 | 0.98 (0.70 to 1.38) | 0.919 |
Synovial effusion (0–3) | 109 | 0.83 (0.52 to 1.31) | 0.420 | 109 | 0.79 (0.44 to 1.41) | 0.421 |
MRI (quantitative) | ||||||
Synovial tissue volume (per 1000 mm3) | 111 | 1.00 (1.00 to 1.00) | 0.612 | 111 | 0.96 (0.88 to 1.04) | 0.327 |
Radiographs | ||||||
Tibiofemoral KL score (0–4) | 187 | 0.79 (0.49 to 1.28) | 0.341 | 187 | 0.52 (0.30 to 0.91)* | 0.021 |
Patellofemoral KL score (0–4) | 188 | 0.86 (0.60 to 1.22) | 0.391 | 188 | 0.80 (0.54 to 1.19) | 0.269 |
Overall KL maximal scorea (0–4) | 188 | 0.72 (0.43 to 1.20) | 0.205 | 188 | 0.43 (0.23 to 0.82)* | 0.010 |
Lateral tibiofemoral JSN score (0–3) | 186 | 1.27 (0.79 to 2.03) | 0.327 | 186 | 0.86 (0.51 to 1.45) | 0.569 |
Medial tibiofemoral JSN score (0–3) | 187 | 0.91 (0.59 to 1.40) | 0.661 | 187 | 0.69 (0.42 to 1.15) | 0.154 |
Patellofemoral JSN score (0–3) | 179 | 0.83 (0.59 to 1.16) | 0.265 | 179 | 0.85 (0.56 to 1.28) | 0.425 |
Overall JSN maximal scoreb (0–3) | 187 | 0.75 (0.49 to 1.16) | 0.196 | 187 | 0.60 (0.36 to 0.99)* | 0.047 |
Knee mal-alignment angle (per degree) | 192 | 0.98 (0.92 to 1.04) | 0.481 | 192 | 1.01 (0.94 to 1.08) | 0.801 |
Longer term response
Predicted probability of response
Probability | |||||||
---|---|---|---|---|---|---|---|
Overall KL maximal gradea
| 0 | 1 | 2 | 3 | 4 | ||
Short term predicted probabilityb
| 0.87d
| 0.83d
| 0.78 | 0.71 | 0.64 | ||
Longer term predicted probability | 0.69d
| 0.49d
| 0.29 | 0.15 | 0.07 | ||
Overall JSN maximal scorec
| 0 | 1 | 2 | 3 | |||
Short term predicted probabilityb
| 0.82 | 0.77 | 0.72 | 0.66 | |||
Longer term predicted probability | 0.38 | 0.27 | 0.18 | 0.12 | |||
Menisci maximal WORMS | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
Short term predicted probability | 0.72 | 0.70 | 0.69 | 0.68 | 0.67 | 0.66 | 0.64 |
Longer term predicted probability | 0.28 | 0.22 | 0.18 | 0.14 | 0.10 | 0.08 | 0.06 |