Knee pain is transmitted via peripheral nerves. Once a medical or orthopedic surgical musculoskeletal approach has failed to relieve this chronic problem, then a partial kneedenervation should be considered. In 1994 the medial and lateral retinacular nerveswere described, and these are the main source for knee joint pain. A nerve block of each of these nerves followed by observation of increased stair climbing and kneelingwith a decrease in the visual analog scale of > 5 predicts a 90% success rate for partial knee denervation. This approach, pioneered by Dellon, is applicable to patients withpersistent pain after partial or total knee arthroplasty, and to those with sports injuriesand pain after ligament reconstruction, and for those too young for joint replacement.This review includes description of the neuroanatomy, the nerve block technique, thesurgical approach and the results of Dellon’s partial knee denervation over the pasttwenty years.