Course of pain, physical functioning and radiographic OA features during follow-up, for total study group (n=588)
| Baseline | T2 | T5 | T8 | T10 | |
WOMAC, mean (SD)
| 5.4 (±3.4) 2.8 (±1.7) 17.2 (±12.0) | 5.2 (±3.5) 2.6 (±1.6) 16.4 (±12.0) | 5.1 (±4.0) 2.8 (±1.8) 17.6 (±12.0) | 4.5 (±3.6) 2.4 (±1.8) 16.3 (±13.0) | 4.7 (±3.8) 2.6 (±1.9) 16.2 (±13.1) |
| NRS past week, mean (SD) | 3.7 (±2.1) | 3.7 (±2.3) | 3.2 (±2.6) | 2.7 (±2.5) | 2.9 (±2.6) |
| Use any pain medication, n (%) | 250 (43) | 263 (48) | 251 (47) | 250 (49) | 249 (50) |
| Hip pain, n (%) | 588 (100) | 374 (68) | 301 (57) | 267 (54) | 247 (51) |
| Knee pain, n (%) | 418 (71) | 361 (65) | 327 (62) | 297 (58) | 264 (53) |
| Morning stiffness (hip) <60 min, n (%) | 326 (55) | 287 (52) | 272 (51) | 239 (47) | 228 (45) |
| Physically active (>30 min) for ≥3 times a week, n (%) | 316 (55) | 319 (60) | 292 (56) | 296 (58) | 276 (56) |
| Cumulative sum of HR, n (%) | 0 (0) | 13 (2) | 41 (7) | 58 (10) | 69 (12) |
| Cumulative sum of KR, n (%) | 0 (0) | 0 (0) | 4 (1) | 9 (2) | 10 (2) |
| K/L grade ≥2 either hip, n (%) | 110 (19) | 128 (22) | 151 (28) | 183 (35) | 253 (49) |
| Clinical knee OA* either knee, n (%) | 206 (35) | 278 (47) | 323 (55) | 349 (59) | 366 (62) |
| Painful internal rotation either hip, n (%) | 322 (55) | 197 (36) | 190 (38) | 166 (36) | 179 (39) |
| Painful external rotation either hip, n (%) | 160 (35) | 86 (17) | 115 (20) | 86 (15) | 89 (20) |
| Painful flexion either hip, n (%) | 315 (54) | 227 (42) | 192 (39) | 149 (32) | 159 (35) |
Values are mean value±SD, or number (percentages, %).
*According to the clinical criteria of the ACR; once those clinical ACR criteria are satisfied, the case will be seen as clinical hip or knee OA.
ACR, American College of Rheumatology; HR, hip replacement; K/L, Kellgren and Lawrence; KR, knee replacement; NRS, Numerical Rating Scale; OA, osteoarthritis; WOMAC, Western Ontario and McMaster Osteoarthritis index.