Neuropathy of the saphenous nerve as a cause of knee pain.

Neuropathy of the infrapatellar branch of the saphenous nerve is a frequently overlooked cause of persistent medical knee pain. The author wishes to identify this as a distinct entity and to present five cases. All of these cases were caused by direct blows to the medial aspect of the knee, did not respond to conservative treatment, and were essentially cured via neurolysis or neurectomy of the infrapatellar branch. Nerve entrapment is a frequent cause of intractable symptomatology in various areas of the body. The most commonly recognized nerve entrapment condition is carpal tunnel syndrome. Another condition, saphenous nerve entrapment, is all too frequently overlooked and underdiagnosed.