Many of you have asked about this procedure that I'll have done next month. I've tried to find some good descriptions and good pictures (non-gory ones) but there's not a lot out there. But I'm going to do the best I can.

In short, here's my problem:

Data from short- and long-term follow-up studies indicate that thigh pain is a significant complication after apparently successful cementless total hip arthroplasty. In most cases, reported symptoms are mild to moderate, resolve spontaneously or do not progress, and require little or no therapeutic intervention. However, persistent thigh pain may be a source of dissatisfaction or may present as severe, disabling pain. Possible causes include bone-prosthesis micro-motion, excessive stress transfer to the femur, periosteal irritation, or a mismatch in Young’s modulus of elasticity that increases the structural rigidity of the prosthetic stem relative to the femur. Thorough diagnostic evaluation of thigh pain is essential to rule out prosthetic infection or loosening, stress fracture, or spinal pathology as the primary source. Treatment options in the aseptic, well-fixed femoral component include medical management, revision of the femoral component, or cortical strut grafting at the tip of the implant.
(Journal of the American Academy of Orthopaedic Surgeons)

Through a process of elimination and some nuclear medicine studies that have shown some loosening of the tip of the implant, my surgeons have determined that a cortical strut graft may, I repeat, may relieve the persistent four-year pain. The procedure, while used commonly after a fracture or to stabilize the femur before a hip replacement in an older patient with thinning bone, has not been used on a wide scale to alleviate post-op thigh pain in THR patients. The results have been mixed. But there is currently no other course of action...and if this doesn't work, then I will just have to live with the pain until such time as other components of the hip fail or are compromised and it needs to be completely redone.

The procedure consists of using a piece of cadaver bone in sort of a collar shape and partially encircling the femur with it at the level of the tip of the implant, about half-way down my thigh. This is then surrounded by metal bands to secure it tightly and give it the best chance to "grow" into my own bone. The hope is that this will stabilize the portion of the bone/stem that is either loosened or that is failing to "give" due to the great difference in elasticity between bone and metal.

The diagram to the left is the best I could find. It does not show a hip implant; rather it shows an allograft being used to correct for a defect in the femur. But the procedure is similar. The pink piece is the donor bone that will eventually graft into the host bone.

The x-ray on the right shows a completed strut allograft in a patient with a hip replacement. The bright white portion is the prosthesis. The thin white bands are holding the donor bone in place. So this will resemble my x-rays when my procedure is complete.

One of the obvious questions is whether there is a possibility of rejection. My surgeons' response and my own research indicate that this is not a problem as it would be with live tissue of some kind. There is very little "living" tissue in cadaver bone and treating for the tiny possibility of rejection would present larger risk than rejection itself.

So...there's about the extent of what I know. The science behind it fascinates me; but more than that the hope of some permanent relief encourages me to undergo one more "swing" at this thing!

Labels: Health, Technology