Gastrocnemius muscle herniation as a rare differential diagnosis of ankle sprain: case report and review of the literature

We present the case of a patient who presented with prolonged symptoms after an ankle sprain. The clinical picture showed a fascial insufficiency with muscle bulging under tension. Ultrasound and MRI imaging confirmed the diagnosis of muscle hernia of the medial gastrocnemius on the right leg. Conservative treatment did not lead to success. Therefore, the fascial defect was treated surgically by repairing the muscle herniation using a synthetic vicryl propylene patch.Muscle hernias should be taken into consideration as a rare differential diagnosis whenever patients present with persisting pain or soft tissue swelling after ankle sprain. Diagnosis is mainly based on clinical aspect and physical examination, but can be confirmed by radiologic imaging techniques, including (dynamic) ultrasound and MRI. If conservative treatment fails, we recommend the closure with mesh patches for large fascial defects.Muscle herniation in the extremities is a rare clinical entity. Most commonly, it occurs as a result of an acquired fascial defect, i.e. after trauma [1]. In symptomatic patients, there can appear pain or discomfort on physical exertion of the affected limb, but also paresthesia or the like by compression of nerves. It is, however, important to note, that the true incidence of the condition of muscle herniation of the lower extremities remains unclear. Many of these herniations are asymptomatic or may be misdiagnosed, e.g. a soft tissue tumor or successfully treated as another condition[2,3]. Often, even MRI findings are non-specific detecting subtle fascial and muscle signal changes[4].Different treatment options for symptomatic extremity muscle herniation in the lower limb have been described [5-9]. These techniques were mostly used for tibialis anterior muscle herniation and include conservative management (activity limitation, compressive stockings...) as well as fasciotomy, direct approximation of the fascial defect, tibial periosteal flap, partial muscular excisio