Background Various upper extremity musculoskeletal diseases (MSDs) can affect pain and disability in patients with hand osteoarthritis (HOA). However, there was no previous study investigating the relationship between upper extremity MSDs and HOA.

Objectives To explore the influence of major upper extremity MSDs on pain severity and functional status of patients with HOA.

Methods In this study, we enrolled 1150 farmers who lived in Gyeongnam province in Korea from June 2013 to December 2015. Physical examinations were performed by rheumatologists, orthopedists, and rehabilitation specialists. Grip powers of both hands also were evaluated. Plain radiography, a nerve conduction velocity (NCV) examination, and magnetic resonance imaging (MRI) of shoulders were performed. The Australian/Canadian Osteoarthritis Hand Index (AUSCAN) was used to assess pain severity and functional status of hand joints. The diagnosis of HOA was made by the 1990 American College of Rheumatology classification criteria. Carpal tunnel syndrome (CTS) was confirmed by NCV findings, and rotator cuff tear (RCT) was diagnosed by MRI findings. Myofascial pain syndrome (MPS) was diagnosed by palpations of myofascial trigger points.

Results Of 1150 participants, 307 were diagnosed with HOA. Among HOA patients, 151 (49.7%), 192 (62.5%), and 249 (80.1%) patients had CTS, RCTs, and MPS, respectively. HOA patients with MPS showed significantly higher AUSCAN scores (350.4±285.0 vs 200.4±201.8, p<0.001) and decreased grip power of a dominant hand (22.5±9.8 vs. 26.2±9.8, p=0.011) compared with HOA without MPS. Linear regression analysis also showed that MPS was associated with AUSCAN scores after adjustment for age and gender (β=0.21, p=0.001). The existence of CTS or RCT did not influence on AUSCAN scores and grip power. Compared to participants with none of major upper extremity MSDs, participants with MPS only were also higher AUSCAN scores.

Conclusions MPS has a significant impact on pain and functional status in patients with HOA. Therefore, management of coexisting MPS is the better way to improve pain and function of hand joints in patients with HOA.

Acknowledgement This study was supported by a grant of the Center for Farmer's Safety and Health, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea.

Disclosure of Interest None declared