TABLE 2.
Quantitative sensory testing (QST) by pain pressure thresholds (PPTs) in knee OA.
| Advanced OA group | Early OA group | Healthy volunteers | |
| Parameter | (N = 76) | (N = 42) | (N = 6 |
| PPT_TK_Pa | 392(225) | 423(227) | 690(192)∗∗ |
| PPT_CK_Pa | 427(327) | 453(210) | 628(62)∗ |
| PPT_TK | 366(214) | 339(155) | 454(115) |
| PPT_CK | 376(179) | 367(153) | 452(99) |
| PPT_TK_M | 345(183) | 359(164) | 1020(231)∗∗∗ |
| PPT_R | 381(186) | 374(143) | 500(63) |
PPTs are shown as mean and standard deviation in parentheses in kPa. Significant differences with a Mann–Whitney U-test were: ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 between healthy controls and all OA subjects. There were no significant differences between advanced and early OA groups (p > 0.3). PPT, pain pressure threshold; PPT_TK_Pa, PPT for the target knee at the patella; PPT_CK_Pa, PPT at the contralateral patella; PPT_TK, PPT at for the whole knee; PPT_CK, PPT for the contralateral knee; PPT_TK_M, PPT for the target knee side at the malleolus; PPT_R, PPT at the right radius.