http://www.bjj.boneandjoint.org.uk/content/96-B/2/263.abstract

Uncemented, custom-made, hydroxyapatite-coated collared distal femoral endoprostheses

Up to 18 years’ follow-up

1. V. Batta, MBBS, MS(Tr&Orth), MRCS, Registrar1; 
2. M. J. Coathup, BSc, PhD, Senior Lecturer1 ; 
3. M. T. Parratt, MBBS, MBChB, MRCS(Ed), Specialist Registrar2 ; 
4. R. C. Pollock, MBBS, BSc, FRCS(Orth), Consultant Orthopaedic Surgeon2 ; 
5. W. J. Aston, BSc, MRCS(Ed), FRCS(Tr & Orth), Consultant Orthopaedic Surgeon2 ; 
6. S. R. Cannon, MCh(Orth), FRCS(Eng), FRCS(Ed), MRCOG, Consultant Orthopaedic Surgeon2; 
7. J. A. Skinner, MBBS, FRCS(Eng), FRCS(Orth), Consultant Orthopaedic Surgeon2 ; 
8. T. W. Briggs, MCh(Orth), FRCS(Ed), FRCS(Eng), Consultant Orthopaedic Surgeon2 ; and 
9. G. W. Blunn, BSc(Hons), PhD, Professor, Director of the Institute1 

+Author Affiliations

1. 1University College London, John Scales Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Division of Surgery and Interventional Science, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP, UK.
2. 2Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP, UK.

1. Correspondence should be sent to Dr M. J. Coathup; e-mail:m.coathup@ucl.ac.uk

Abstract

We reviewed the outcome of 69 uncemented, custom-made, distal femoral endoprosthetic replacements performed in 69 patients between 1994 and 2006. There were 31 women and 38 men with a mean age at implantation of 16.5 years (5 to 37). All procedures were performed for primary malignant bone tumours of the distal femur. At a mean follow-up of 124.2 months (4 to 212), 53 patients were alive, with one patient lost to follow-up. All nine implants (13.0%) were revised due to aseptic loosening at a mean of 52 months (8 to 91); three implants (4.3%) were revised due to fracture of the shaft of the prosthesis and three patients (4.3%) had a peri-prosthetic fracture. Bone remodelling associated with periosteal cortical thinning adjacent to the uncemented intramedullary stem was seen in 24 patients but this did not predispose to failure. All aseptically loose implants in this series were diagnosed to be loose within the first five years.

The results from this study suggest that custom-made uncemented distal femur replacements have a higher rate of aseptic loosening compared to published results for this design when used with cemented fixation. Loosening of uncemented replacements occurs early indicating that initial fixation of the implant is crucial.

Cite this article: Bone Joint J 2014;96-B:263–9.

Footnotes

• The authors would like to thank S. Cro for her contribution to the statistical analysis.
  No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.
  This article was primary edited by G. Scott and first-proof edited by D. Rowley.

• Received March 27, 2013.
• Accepted October 1, 2013.

• ©2014 The British Editorial Society of Bone & Joint Surgery