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Knee
Distal Femoral Allograft Reconstruction for Massive
Osteolytic
Bone Loss in Revision Total Knee Arthroplasty
Bezwada HP *, Shah AR **, Zambito K **, Cerynik DL **, Johanson
NA **
*Penn Orthopaedics, Pennsylvania Hospital, Philadelphia, Pennsylvania
**Department of Orthopaedic Surgery, Drexel University College of
Medicine, Philadelphia, Pennsylvania
 Introduction
Massive osteolytic bone loss of the distal femur following
total knee arthroplasty (TKA) continues to present significant
reconstructive challenges for revision TKA. Osteolysis has
been associated with backside wear of modular polyethylene
inserts, and this factor combined with compromised polyethylene
material properties has been thought to significantly increase
the risk of accelerated wear.1
Bulk femoral allografting has been shown to provide an attractive
solution for addressing bone defects. They may be intraoperatively
customized to approximate the shape of the defect, and their
use is relatively cost-effective compared to custom or custom-like
implants.2 Controversy exists regarding the optimal mode
of stem fixation. Cemented and cementless techniques have
been advocated. The purpose of this study is to evaluate the
short-term outcome of cemented revision TKA utilizing bulk
allograft to fill massive osteolytic femoral lesions.
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Materials and Methods
11 knees (10 patients) underwent revision of failed modular PFC
(Johnson and Johnson Orthopaedics, Raynham, MA) TKA from 2001 to
2002. All patients had Type III femoral defects (Anderson Orthopaedic
Research Institute bone defect classification system). Mean time
to revision of index arthroplasty was 6 years. Mean follow-up was
42 months (range 36-48 months).
Results
Serial radiographs of all 11 revisions, including those at final
follow-up (range 24-36 months) demonstrated no signs of graft demarcation,
resorption, host bone osteolysis, radiolucent lines or migration
of the implants.
Discussion
The utilization of bulk distal femoral allografts and cemented long-stemmed
revision implants has been successful in the short-term with no
evidence of loss of cement fixation. This technique provides reliable
and durable protection of the allograft during the bony in-growth
process. The recent addition of malleable bone graft substitutes
at the graft-host interface may provide additional enhancement of
allograft incorporation.
References
1. Engh GA, Lounici S, Rao AR, et al. In vivo deterioration of tibial
baseplate locking mechanisms in contemporary modular total knee
components. J Bone Joint Surg 2001;83A:1660.
2. Clatworthy MG, Ballance J, Brick GW, et al. The use of structural
allograft for uncontained defects in revision total knee arthroplasty.
A minimum five-year review.
J Bone Joint Surg 2001;83A:404.
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