Indications for the BMHR
The Birmingham mid head resection prosthesis is a new implant invented over a year ago by Dr. Derek McMinn. It is useful in those patients who are sold on the idea of a hip resurfacing but unfortunately don’t have enough bone stock in the femoral head.
After x rays, the surgeon can predict pre- operatively which patients are going to require a mid head resection resurfacing prosthesis rather than a Birmingham hip resurfacing.
These are patients with
1) Osteoarthritis with large cysts
2) Avascular necrosis > 40 %.
3) Perthes disease
4) Slipped capital femoral epiphysis.
In these cases the surgeon can go in for a BMHR rather than a BHR.
Particularly in AVN with large bony involvement, hip resurfacing is not possible. In these cases, BMHR is ideal as it behaves like Hip resurfacing but all diseased bone is removed. Yet more bone conserved during BMHR is more than a total hip replacement.
The prosthesis uses the same cup as a BHR. On the femoral side, a modular head component fits onto a short conical stem confined to the neck of the femur.
BMHR surgery is very exacting. Dr.Venkatachalam got exposure in Australia for this surgery.