BIRMINGHAM MID HEAD RESECTION (BMHR)
The application of this special implant after McMinn is a further bone-conserving operative method for patients, who are not allowed to get a resurfacing.
The advantages of the mid head resection:
The known benefits of resurfacing are true here as well. The implants in natural size allow natural motion and higher safety, concerning the danger of dislocation. The joint sensibility and reflexes are preserved. No changes in leg length and leverage of hip muscles take place. The natural force transmission from the pelvis to the femoral head and femur does not lead to change in bone structure or bone loss, but increases bone density. The proximal femur is preserved to provide very good conditions for all kinds of prosthesis shafts, in case of revision surgery. In most cases, a quicker recovery is possible.
The difference from hip resurfacing is not clinically recognizable. Special attention should be paid to fact that this procedure can also be performed in case of inborn dysplasia with shortened femoral head-neck segment, extensive avascular necrosis of the femoral head, large cysts of the femoral head, malformations, destroyed bone substance and bone resorption. If the bone density and the shape of the femoral head do not offer sufficient support for the implant, resurfacing is not possible. With healthy and active patients, the mid head resection is an alternative to a standard prosthesis. With this prosthesis, the fixation of the femoral element depends less on the bone of the femoral neck, but more on the stability of the titanium stem, implanted in the femoral neck and functioning as an anchor. The part of the femoral neck, destroyed by cysts, circulatory disorders, malformation or resorption due to arthrosis is previously removed. A titanium stem, adjusted to the size, is placed into the healthy part of the femoral head and the femoral neck, which is connected with the bone and strengthens the femoral neck. The implant-bone compound can stand bending forces in this way. With this implant, it is possible to avoid the opening of the femoral medullary cavity, due to the implantation of a prosthesis stem. The advantages of resurfacing remain unchanged. There is no functional difference to the positive results of resurfacing. The own study on this implant will be published soon.