A long story of postoperative knee pain …finally vanquished!

Post operative surgical knee pain affects a good portion of total knee arthroplasties. At one-year 13% of patients who have had a total knee replacement have chronic debilitating pain. At two years that number drops around 8% and then by three years it settles around 5 to 7% which is still one in 20 people with disabling knee pain. Despite architecturally sound, and mechanically functional knees, they can still hurt. Why? The brain is designed to feel sensation from the joints. Proprioceptive sensation, actual frank, tactile sensation from the joint capsule and all the spindles and tendons and Golgi apparatus around the knee report back to the brain. The failure of that reporting to the brain in some folks predisposes to a syndrome of pain from a failure of the brain matrix. The brain is looking for sensation and replaces sensation with pain. The same can be seen in tinnitus where a band of the spectrum of sound is no longer reported to the brain, the brain simply replaces it with a ringing sensation, the sonic equivalent of neuropathic pain So here is KF. A patient I saw initially along time ago before I left for sabbatical who had had peripheral nerve blocks etc. all the attendant easy tricks of our trade . She tried physical therapy. She tried diet rest changes in footwear, bracing, massage and ultimately while I was gone on sabbatical she had a spinal cord stimulator implant. Sadly, the results were Not successful. About a year and a half after that, she went back and had a revision. Sadly, even with a revision, no improvement. She then had multiple discussions regarding revision of the actual knee replacement, more surgery, ablation of the nerve to go to the knee, ablation of the saphenous nerve that innervates the patella and consideration evening of intrathecal placement of morphine and fentanyl inside the spine. Once I got back from sabbatical, we tried a dorsal root ganglion stimulator, but it was simply too painful to put in for her. Having resigned myself that the revision of her stimulator had given neuromodulation its best shot, I failed to press about overlap of paresthesia. We went back to the OR and reposition the lead yet again, but this time very significantly pulling the two leads down approximate 3 vertebral bodies, doing a Intraoperative trolling so to speak so that the paresthesia from the stimulator overlapped her painful right knee. I resecured the leads to the anchors and sewed her up and sent her home. I knew we had overlap, but what I didn’t know was how successful it would be. So when she came in and told me, she essentially had no pain anymore I was thrilled. It is a great joy to practice and a great privilege to practice interventional pain medicine . We must keep doing @anodyneresearch. #painmatters!