[Correlation between cold pain of knee joint and subchondral bone marrow edema in patients with knee osteoarthritis]

To investigate relationship between cold pain of knee joint and subchondral bone marrow edema (BME).

From May 2018 to August 2019, 92 patients with knee osteoarthritis (KOA) associated with cold pain of knee were admitted, all patients were underwent MRI examination. The patients were divided into observation group (47 patients with BME) and control group(45 patients without BME). In observation group, there were 6 males and 41 females aged from 36 to 87 years old with an average of (63.2±12.3) years old. In control group, there were 10 males and 35 females, aged from 48 to 84 years old with an average of (62.7±8.3) years old. All patientswere treated with drugs. The degree of joint degeneration was evaluated by Kellgren-Lawrence (K-L) grading. Degree of cold pain of knee was evaluated by knee cold pain score, and degree of BME was evaluated according to WORMS. The correlation between cold pain of knee and K-L grading and BME was analyzed.

Score of cold pain in observation group (15.55±7.68) was higher than that of control group (9.42± 5.50), which had significant difference (t=4.383, P<0.001). There was no correlation between cold pain of knee and K-L grading(χ²=2.138, P=0.907). There was correlation between BME grading and degree of cold pain in observation group(χ²=19.709, P<0.001), and Spearman correlation coefficient was rs=0.509(P<0.001).

The cold pain of KOA patients is not related to K-L grading, but corelate with BME grading. The Cold pain of knee was more pronounced in KOA patients with BME, and the severity of BME is often related to degree of cold pain. It seemed to be a tendency:the more serious BME, the heavier coldpain.