[Neuropathic pain following lesions of the infrapatellar branch of the femoral nerve : an important differential diagnosis in anterior knee pain].

We report on two patients with neuropathic knee pain following lesions of the infrapatellar branch of the femoral nerve due to knee joint replacement. In one patient, the neuropathic pain syndrome was complicated by the development of complex regional pain syndrome (CPRS II, causalgia). Patients exhibit a sharp, burning pain, often induced by exercise, and sensory impairment in the skin area supplied by the infrapatellar nerve. This nerve is a branch of the femoral nerve medial to the fascia lata and is responsible for the skin sensation of the anterior and medial part of the knee. Clinical features, anatomy, diagnostic methods and therapeutic options are reviewed.