The Association between Ultrasound Results and the Hyaluronic Acid Treatment Response in Patients with Knee Osteoarthritis

Objective: Knee osteoarthritis (OA) is common in middle-aged and elderly people. Patients with knee OA can use hyaluronic acid (HA) injection therapy if they meet certain requirements. The purpose of this study was to delineate the effects of HA injection in patients with knee OA and to identify factors associating with the efficacy of the injections by using musculoskletal sonography (MUS). Methods: We included 100 patients with knee OA in this study from May 2012 to May 2013. The patients were evaluated using MUS 4 to 5 weeks after receiving a complete course of intraarticular HA injection. Radiographic and overall clinical assessments were conducted and a chi-square test was used to perform statistical analysis. Results: The mean ages of the men and women in the patient group were 72.6 years and 63.7 years, respectively. Most of the patients were women (86%). Approximately 61% of the patients (response group) exhibited favorable responses to the HA injections. The MUS findings indicated that only 21% of the patients exhibited Baker's cysts, osteophytes were present in 80% of the patients, and 69% had joint effusion. Fewer than half of the patients developed synovial proliferation (44%). The nonresponse group was highly correlated with joint effusion, Baker's cysts, and synovial proliferation (p ＜ 0.05). Conclusion: Our study indicated that joint effusion, Baker's cysts, and synovial proliferations should be treated before HA injection in order to obtain better treatment response.