Background:
Arthropathy is one of the major complications in hemophilia, leading to functional limitations and poor quality of life. Exercise is recommended as being beneficial for people with hemophilia, yet a lack of exercise-related evidence using exercise and control groups exists in this population, compared to other joint pathologies (i.e. osteoarthritis).
Objective:
To evaluate effects of post-hemarthrosis exercise on: pain; swelling; bone density and joint damage, using an animal model.
Methods:
Twelve Wistar rats were divided into an Exercise Group (EG; n=6) and Control Group (CG; n=6). All rats received eight weekly intraarticular injections in their right knees with 0.1 mL autologous blood, and left knees with 0.1 mL saline solution. The EG performed an 8 wk swimming protocol (during the period of intraarticular injections) of 60 min (5x week) with 5% body weight attached on their tails. Pain status was assessed weekly with a static weight-bearing incapacitance test (SWIT). Joint diameters were measured post-protocol with a digital microcaliper. Bone mineral density was assessed using dual-energy X-ray absorptiometry (whole-body, tibia, femur and knee joint) pre and post-study. Following sacrifice, bilateral knee X-rays were taken and scored with Pettersson’s score. Resting heart rate and heart weight were registered post-study, as markers of physical training.
Results:
CG manifested decreased weight-bearing with SWIT, compared to EG (p<0.001). EG presented reduced joint swelling, compared to CG (p=0.034). Significant increase in bone mineral density variation (BMD∆) was observed at the tibia (p=0.016), and knee (p=0.018) of the EF compared to CG. The EG also showed a tendency of an increase in femoral BMD∆ compared to CG (p=0.09). Pettersson scores demonstrated increased bone destruction in the CG compared to EG (p=0.05).
Conclusion:
This is the first time that beneficial effects of a swimming exercise protocol on pain, swelling, bone density and radiologic changes have been shown in a blood-induced, joint damage animal model. Hopefully this data will provide clues for future study designs in this area.