A Comparative

[Guest guest]

I was doing some research for my soon to be filed appeal for my soon

to be received denial from my insurance company for resurfacing. I

came across an interesting article that I thought I would share with

the group since comparisons have been made the last couple of days.

Also, the site where I found the article is a nice site for

information. There are several other articles that were interesting

and most likely will be others in the future. This may have already

been shared but I missed it. Sorry if it is repetitive!

The site I found

it was:

http://www.totaljoints.info/what_new1.htm

It's called TEST/News

"

March 2004

24 / 03 / 2004

THE BIRMINGHAM SURFACE HIP – more details

The report about the excellent results of the Birmingham surface hip

replacement device (see the 19/03 2004 NEWS: Surface hip replacement)

raised several questions among the readers of the NEWS page (see also

the Opinion page).

Many readers were surprised by the difference between the results of

the American (Amstutz 2004) and the British ( 2004) surgeons.

According to doctor Amstutz report, 94.4% of his entire surface hip

group survived for four years; in the Birmingham group 99.7% of all

surface hips survived seven years.

Doctor Amstutz observed both surface hip dislocations and fractures

of the femoral collum stump; no such complications were observed in

the Birmingham patient group.

Doctor Amstutz used the Conserve Plus model manufactured by MT

Company, the British surgeon doctor McMinn used the Birmingham Hip

Resurfacing devices manufactured by MMT Company. Naturally, the

question arises whether the two different surface hip models in some

way influenced the results, if the one resurfacing hip model is

better than the other one.

I do think that the difference in the results between doctor Amstutz

group and the doctor McMinn patient groups does not depend on the

type of the surface replacement device used. The difference in the

results depends in my opinion on different patients selection by the

two surgeons.

Doctor Amstutz's patients have had a wide range of hip diseases. Only

two thirds of them have had primary osteoarthritis of the hip as the

reason for surgery; 10% of them have had severe osteonecrosis of the

femoral head, 8% have had previous hip fracture, and 6% have had

previous surgery. These diagnoses are known to bear greater risk for

eventual failure of the surface replacement.

On the other hand, the Birmingham patient group consisted of very

closely selected patients with only one diagnosis: idiopathic hip

osteoarthritis. The hip joints of these patients have had no

deformities, cysts, bone necrosis or other defects in the skeleton;

these patients did not have previous operations, hip fracture or

other joint diseases that increase the risk of failure of the surface

hip replacement.

Moreover, doctor McMinn excluded from the study 30% of his patients

who have had high failure rates! He says that these excluded

patients have had a wrongly manufactured surface replacement device

that caused the high failure rates.

In my belief the excellent " 99% + " results of the Birmingham hip can

be reproduced only on patients with the idiopathic osteoarthritis of

the hip joint. Patients with other hip joint diseases and

deformities, such as developmental hip dysplasia, avascular necrosis,

rheumatoid arthritis, and previous fracture should rather expect the

more realistic results achieved by doctor Amstutz.

Actually, there are reports about very disappointing results with the

McMinn Resurfacing Hip Arthroplasty. Japanese surgeons published a

report that demonstrated 3 failures among 11 patients operated on

with the McMinn Resurfacing Hip Arthroplasty. (Watanabe 2000). Two of

their patients sustained femoral neck fractures, and the third

developed loosening in the acetabular component early after the

surgery. The Japanese surgeons believe that this surface replacement

device is not appropriate for patients with brittle or soft bones

because of its biomechanical characteristics.

Doctor Amstutz discusses extensively the appropriateness of surface

hip replacement for these patient categories, but such discussion is

lacking in the McMinn paper.

Your opinion?

____________

References:

Amstutz H et al.: J Bone Joint Surg-Am 2004; 86-A : 28 - 39

J et al.: J Bone Joint Surg- Br 2004; 86- B : 177 – 84

Watanabe Y et al: J Arthroplasty 2000; 15: 505 - 11

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