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Allogran-N
Research Article
68 year old female showing
evidence of femoral loosening of a cementless stem and a
large lytic area in the roof of the acetabulum
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Twelve months following
surgery. Excellent incorporation of the stem has been
achieved with no evidence of distal migration
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Impaction Grafting with Allogran-N
Variables Affecting Initial
Stability of Impaction Grafting for Hip Revision.
Clinical Orthopaedics & Related
Research. (432):174-180, March 2005.
Gokhale, Satish FRCS ORTH ; Soliman,
Ayman MSCORTH ; Dantas, João Pedro MD ; Richardson, James
Bruce MD ; Cook, Frank BSC ; Kuiper, Jan-Herman PhD ; Jones,
Peter PhD
Impaction grafting in revision
arthroplasty was originally described for use in the
acetabulum1,
and later adapted for use in the femur2.
The process involves cementing a femoral component into
compressed bone graft.
An advantage of impaction grafting
in orthopaedic revision surgery is the restoration of bone
stock. However, the bone graft matrix requires more than the
ability to support the in-growth of host bone tissue. A high
level of physical robustness and structural integrity is
required to withstand the dynamics of compaction involved in
impaction grafting.
Allograft is commonly used for
impaction grafting for hip revision. However, this is
sometimes in short supply, and of variable quality. In many
cases, osteoarthritic femoral heads are used by morselising
the head to bone chips, the result of which is combined with
fresh blood from the patient.
In 17 hip revision cases from the
study of 56 patients, there was a shortage of available bone.
The bone available was therefore combined equally with
Allogran-N, a granular Hydroxyapatite bone graft substitute.
This 50:50 mixture was then combined with fresh blood from the
patient.
Allogran-N has been designed for use
as a bone graft extender to be used in conjunction with
allograft material, in order to reduce the surgeon’s reliance
on allograft tissue, and the risks that have been associated
with it’s use3.
The study explores the variables
affecting initial stability of impaction grafting for hip
revision. As Allogran-N was used in the study, this was one of
the factors considered when analysing clinical results by
multiple regression statistical analysis.
From the conclusions, it was evident
that the use of Allogran-N as a synthetic bone graft extender
was successful. Allogran-N’s hydroxyapatite granules did not
adversely affect cup migration or stem subsidence.
These results indicate that the use
of Allogran-N to augment allograft bone stock is an effective
method of reducing dependence on allograft, without
compromising performance requirements relating to graft
stability.
References
1. Sloof T J, Huiskes R, van Horn
J, Lemmens A J : Bone
grafting in total hip replacment for acetabular protrusion.
Acta Orthop Scand 55:593-596, 1984
2. Fowler J L, Gie G A, Lee A J,
Ling R S: Experience with the Exeter total hip
replacement since 1970. Orthp Clin North Am 19: 477-489, 1988
3.
AAOS Bulletin, October 2004, Vol 52, No.5. “FDA’s tissue
action plan: Safeguarding the public”
ORDER CODES
10cc 700-010
35cc 700-035
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