Characteristics of Muscle Recovery under Experimental Post-Traumatic Contracture

Abstract

The frequency of traumatic injuries of the maxillofacial area and the degree of their severity, have been increasing in recent years. The introduction of modern methods of treatment made it possible to improve the results of treatment and shorten its duration. Myogenic contractures develop as a complication after facial injuries, soft tissue injuries, in particular, masticatory muscles. The gastrocnemius muscle of a rat has the same striated structure as the pterygoideus medialis muscle of a person. The purpose of the work is to study the regeneration of striatal muscles with post-traumatic contractures on the basis of combined treatment of laboratory rats. Materials and methods. The study was carried out on 45 sexually mature 12 months old outbred white male rats, which weighed 180-200 g. In animals, reflex post-traumatic muscle contractures (traumatic myositis) resulting from the slaughter of calf muscles (without violating the integrity of muscle tissue) were simulated on the posterior left leg. The rats were divided into two groups. Group 1 included 21 animals that did not receive treatment and whose wounds healed by secondary intention. Group 2 included 24 rats that received combined treatment: on the 2nd day after surgery – general (oral) administration of the drug with the active substance cyclobenzaprine hydrochloride – 0.15 mg, once a day with daily procedures of magnetic laser therapy on the affected hind limb. Results and discussion. Depending on the signs of pain behavior (changes in behavior, restriction of movement, increased sensitivity, pain), the intensity of myogenic pain syndrome was assessed (low, moderate, high, very high). It was found that the use of combined treatment (magnetic laser therapy and the use of cyclobenzaprine hydrochloride) led to the normalization of behavioral and motor reactions by the 28th day: 56% of rats didn’t feel any pain and 44% had a low level of pain. The animals with the same trauma, which weren’t treated, showed a high and moderate level of pain. On the 28th day these animals could lean on their hind limbs while they were moving. However, they could not fully move due to a sharp restriction of their left hind limb function. The obtained results are the basis for the development of new approaches to improving the methods of prevention and rehabilitation treatment of contractures using magnetic laser therapy and central muscle relaxants. Conclusion. It was found that the use of magnetic laser therapy and cyclobenzaprine hydrochloride inhibited the development of an acute inflammatory reaction in the damaged muscle tissue of the hind limb of animals, accelerated and optimized reparative processes, which prevented excessive, functionally significant growth of connective tissue