Effects of cryotherapy on knee osteoarthritis induced by anterior ligament transection: evaluation of nociception and inflammation

Abstract

The osteoarthritis is the most common degenerative joint disease and mainly affect the knee joint. This progressive disease is marked by presence of joint pain, increased of inflammation in synovial fluid and functional limitations. In order to control its symptoms, the standard treatment consists on pharmacological and non-pharmacological interventions and, among these, the cryotherapy is an effective physical agent which has low cost and easy use, and has been employed as an alternative for pain control, inflammation and improvement of function in several musculoskeletal affections. Although its effects are well established in the treatment after acute traumas and has been also used in different chronic musculoskeletal affections, there is a lack of scientific evidence about its effects on chronic joint diseases as knee osteoarthritis (KOA). Aim: To analyze the effects of cryotherapy on nociception and inflammation on chronic KOA induced by anterior cruciate ligament transection (ACLT) on rats. Methods: Adult male rats (Wistars) will be randomly allocated into 2 groups (n=10/group): 1 - KOA (ACLT knee surgery); 2 - ACLT and cryotherapy (ACLT + cryo: ACLT and intervention with ice pack around the knee). After 60 days of transection, with the KOA installed in all groups, the animals will be evaluated (pre-intervention) regarding: mechanic (Von Frey test) and thermic (hot plate) nociception; gait (paw print test). From the 61th to 65th days, the group ACLT + cryo will receive the intervention, that will consist of two daily applications of cryotherapy, at morning and at afternoon, during 20 minutes, with interval of 4 hours between the sessions. On the 66th day, the animals of two groups will be assessed (post- intervention) and right after submitted to euthanasia for collection of synovial fluid from the knee joint (dosage of neutrophil). For the statistical analysis, it will be used the ANOVA test (mixed two ways and one way), with significance level of 5%. In conclusion, the findings of this study may provide new scientific evidence about the effects of cryotherapy on the chronic KOA. Key-words: knee joint, joint inflammation, physiotherapy, ice therapy. (AU)