BIRMINGHAM HIP RESURFACING AFTER MCMINN (BHR)
As opposed to standard prostheses, this procedure includes the removal of diseased surfaces only; the femoral head and femoral neck are preserved. The femoral head is crowned with a metal cap, which consists of a special cobalt-chrome-molybdenum alloy with high carbon content, similar to the thin-walled acetabular cup.
Beside the advantages of bone preservation and tissue protection, this implant is very suitable for young and young at heart patients, who actively participate in life, but are impaired in their private and/or professional activities, due to their hip joint disease. The pain is particularly essential here, as well as the restriction of movement. However, stable bone conditions, especially in the head and neck area of the femur, are indispensable for performing the resurfacing.
Advantages of hip resurfacing over standard prostheses:
- he implant imitates the natural size of a human hip joint and allows in this way a natural degree of mobility 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, if compared to standard procedures. Experience shows that it is easier to return to private and professional activities, including sport. The abrasion resistance resulting from lubricated friction and the very low risk of dislocation mean for the patients that they can go in for such types of sports, where conventional prostheses cannot be recommended. This also holds true for professions, which practice with a standard prosthesis is impossible or risky.
The general statements, however, cannot be made: it is recommended that you have a detailed medical consultation, in order to clarify for you individually, if tennis, skiing, Judo or professional dancing are really possible for you after the surgical intervention.
The idea of BHR prosthesis, to cover the surface of the femoral head only, is not new: the implementation trials started in the 1970s and 1980s, but could not establish itself due to the lack of money. So the medical research focused predominantly on further development of standard procedures and improvement of implant materials.
Derek McMinn, the surgeon at the Nuffield Hospital in Birmingham, Great Britain, finally discovered a promising material in 1989 and took up again the idea of resurfacing. In studies the load-bearing capacity of the implant has been examined in detail and in 1997 it was introduced as the first modern hip resurfacing implant.
For over 16 years and with more than 85.000 patients, the original implants after McMinn (Birmingham hip resurfacing) have achieved excellent results that have been confirmed through numerous scientific publications. Meanwhile, other prostheses developer and manufacturer have also discovered hip resurfacing and offer the corresponding implants in different composition of matter and designs. Here it is necessary, as with any new implant, to test in clinical studies, how durable and functional these implant models are.