What is the BMHR and Why do we need it?
View Youtube Video about BMHR by Mr. McMinn by click below:
BMHR Video Part 1
BMHR Video Part 2
BMHR Video Part 3
Derek McMinn talks about the Birmingham Mid Head Resection
prosthesis and its applied use in patients with Avascular
Necrosis.
For patients with osteonecrosis involving a larger volume of
the femoral head, an uncemented short-stemmed prosthesis,
the Birmingham Mid Head Resection, BMHR, (MMT Ltd,
Birmingham, United Kingdom, now Smith and Nephew
Orthopaedics Ltd, Bromsgrove, United Kingdom) was developed.
Mr. McMinn has implanted about 40 BMHRs to date March 2008.
 |
| Illustration showing the three types of prostheses
implanted in patients with femoral head avascular
necrosis. |
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Birmingham Mid Head Resection prosthesis is an advancement in the BHR and will expand the indications for hip resurfacing surgery. Birmingham Mid Head Resection prosthesis (BMHR) helps advanced aged patients to have Birmingham Hip
Resurfacing.
The BMHR has specifically been designed for patients who have weaker bone in the head of the femur. In the BMHR more of the weak bone is resected and is replaced with metal. This will dramatically increase the range of patients who can have this surgery.X-ray wise it looks almost like the BHR but the amount of bone removed is more. Thus the risk of fracture in post-op is reduced or eliminated for borderline patients.
It is technically complex to do and hence has been released only to select surgeons like Dr.Bose around the world.
ARCH (Asian Regional Centre for Hip Resurfacing),
where Dr. Bose performs Birmingham Hip Resurfacing (BHR) has been
selected to be one of the very few centres worldwide to do BMHR (
Birmingham Mid Head Resection prosthesis). This will be the only
centre in Asia to offer the Birmingham Mid Head Resection
prosthesis.
Birmingham Mid Head Resection Prosthesis (BMHR) X-rays
Indications for the Mid Head Resection
Prosthesis:
-
Developmental dysplasia with shortened femoral
head-neck segment
-
Extensive avascular necrosis of the femoral head
-
Large cysts of the femoral head
-
Abnormalities through Epiphyseolyses and Morbus
Perthes (femoral head necrosis of children)
-
Reduction of bone substance due to arthroses
-
Marked bone involution through inactivity but
with regression potential
X-Ray of BMHR in place
In cases of advanced arthrosis, a defect of the femoral head occurs
which prevents the reliable anchoring of the resurfacing component.
The titanium stem grows into the healthy part of the femoral head
and neck, and is a safe base for the head component.
Resurfacing is only advisable when the stability of the bone and the
shape of the femoral head offer sufficient support for the
prosthesis. With healthy and active patients who do not meet these
requirements but who can benefit from a bone conserving process, the
Mid Head Resection can be an alternative to a standard prosthesis.
With this prosthesis, the fixation of the femoral component depends
less on the bone of the femoral head but more on the stability of a
titanium stem with bone ingrowth in the femoral neck.
Those parts of the femoral head which have been destroyed by cysts,
circulatory disorders, malformations or involution due to arthrosis
are removed. A titanium stem adjusted to size is implanted into the
healthy part of the femoral head and neck, which is fixed by bone
ingrowth (combines with the bone) and strengthens the femoral neck.
In this way the implant-bone compound can withstand bending and
torque forces.
Through the use of this implant, an opening of the femoral medullary
cavity can often be avoided by implanting a prosthesis stem. The
advantage of resurfacing is retained.
