Pathologie traumatique du muscle strié squelettique

Striated muscle injuries of the limbs are quite usual in sports medicine. All grades of severity can be met but several basic principles of diagnosis and treatment allow providing a solution in most of the cases. After a brief review of the histological structure of the striated muscle and the risk factors for muscle injury, this chapter will separately analyse the management of acute- and chronic-muscle strain. It is necessary to distinguish between direct injuries, secondary to direct blow, and indirect ones, the most frequent, where the intrinsic strength of the muscular tissue is overwhelmed by the velocity and magnitude of the external forces. In most of the cases, histological lesion occurs at the myo-aponeurosis or myo-tendinous junction. In the acute setting, clinical examination and imaging allow identifying the lesion type (contracture, tear, rupture), the severity, the location, and to draw the consequences in terms of therapeutic strategy and disability duration. Ultrasonography is here a key for the diagnosis and the prognosis evaluation. Diagnosis of chronic muscle injuries relies also both on clinical examination and imaging. Imaging identifies the type of injury: fibrous scar, pseudo-cyst, calcifications. Due to its 3-D representation MRI is the best imaging tool for diagnosis and for pre-operative planning. Prevention plays a major role in avoiding muscle injuries. Investigating for the athlete's specific risk factors, correcting muscle balance and metabolic disturbances, training properly, improving muscle flexibility have significantly decreased the incidence of muscle injuries. Most acute injuries are treated conservatively. Therapy is adapted to the type of the lesion: physiotherapy, rehabilitation, eccentric isokinetic muscle strengthening, appropriate training and return to athletic activities avoid injury recurrence. Surgery is indicated only in case of major muscle lesions or compressive syndromes. Chronic muscle injuries are most of the time best treated by surgical means. The surgical method and strategy will depend on the type of lesion: from the excision of a simple fibrous scar or calcifications to functional removal of a muscle, sometimes associated with local neurolysis.