Infrapatellar Branch of the Saphenous Nerve Injury: Implications for the Physical Therapist

Abstract

Injury to the infrapatellar branch of the saphenous nerve (IBSN) is an underreported condition which has important implications for the physical therapist. Due to its location, the IBSN is especially vulnerable to damage following surgery, but it may also be injured through trauma or unknown causes. Patients with suspected IBSN injury may present with a variety of symptoms, including pain along the nerve distribution, paresthesia, hypoesthesia, anesthesia, and impaired functional activities and mobility. As the presence of IBSN injury may not be readily apparent, it is incumbent upon the physical therapist to recognize the signs and symptoms associated with this condition, and to administer a detailed clinical examination. Clinical evaluation can be difficult, as IBSN injury mimics many other conditions of the knee. Additionally, saphenous nerve anatomy exhibits wide variance, even within individuals, making diagnosis challenging. Upon suspicion of IBSN injury, the physical therapist should refer the patient for a comprehensive medical exam, which may include nerve blocks, nerve conduction studies, MRI, CT scan, or exploratory surgery. Most patients respond well to surgical intervention, including neurolysis or neurectomy, though conservative treatment options exist. These include nerve blocks or pharmacologic interventions. Physical therapy treatment is not well reported and may only be appropriate for specific etiologies of injury.