1 / 27

Conservative Hip Replacement for avascular necrosis

Conservative Hip Replacement for avascular necrosis. E. Munting, P. Poilvache Cliniques Universitaires Saint-Luc, Bruxelles Clinique Saint-Pierre, Ottignies Hôpital de Waterloo-Braine. THR in patients < 55 y. Revision rate : from 20 % at 5 years to 12 % after 20 years follow-up

weldon
Download Presentation

Conservative Hip Replacement for avascular necrosis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Conservative Hip Replacement for avascular necrosis E. Munting, P. Poilvache Cliniques Universitaires Saint-Luc, Bruxelles Clinique Saint-Pierre, Ottignies Hôpital de Waterloo-Braine

  2. THR in patients < 55 y. Revision rate : • from 20 % at 5 years • to 12 % after 20 years follow-up - Conflicting reports - Implant dependent - Patient dependent (activity…)

  3. Femoral component : options • Preservation of the femoral head and resurfacing • Replacement of the femoral head and : • fixation in the diaphysis (stem) • fixation in the metaphysis

  4. Femoral head replacement with metaphyseal fixation … an old idea ! 1938 Wiles 1954 Postel and Merle d'Aubigné 1941 McKee 1957 Picchio 1949 Judet and Judet 1980 Huggler and Jacobs 1952 Thomson 1982 Munting and Vincent 1953 Haboush

  5. Specification chart • Preserve bone stock • Normal stress pattern in the bone • Femoral head replacement • Easy revision

  6. Conception and Experimental work • Design and biomechanical assessment of prototypes on a hip simulator • Finite Element analysis of experimental and clinical cases • Hydroxyapatite coating development and animal experiments

  7. Implant design study

  8. Femoral component • No medullary stem • Screws for initial fixation • Hydroxyapatite coating • Modular head

  9. Fixation : Geometrical interference • Angular resection of the femoral neck • Lamellae in the proximal metaphysis • Cortical and cancellous support

  10. DXA Study(prospective, 21 hips, 6-9 y. F-up) • BMD is maintained in the proximal femur • In patients with low initial values as compared to the controlateral side, BMD increases after surgery J. Arthroplasty 12, 373-9, 1997

  11. Pilot study • 04/1989 – 01/1992 • 43 patients, 48 hips • 33 males, 15 females • Mean age: 36.4 years (19 – 49)

  12. Etiology (pilot study n = 48) • Primary arthritis 6 • rheumatoïd arthritis 4 • Ankylosing spondylitis 5 • Septic arthritis 2 • Post-traumatic arthritis 7 • Congenital dysplasia / dislocation 6 • Aseptic necrosis 12 • Miscellaneous 6

  13. Results (pilot study n: 48) • Follow-up : 14 to 16 years • 1 patient (2 hips) deceased • 3 lost to follow-up (living abroad) • 18 revised : 8 early revisions (malposition) 10 late revisions (polyethylene wear) • 26 hips known to be functional.

  14. Revisions secondary to implant malposition (n=8) • Varus position : CDA < 120° (n=6) • lack of contact with the bone resection (n=2)

  15. Second series • 01/1995 – 05/2000 • 154 hips • Mean age: 40.8 years (17 – 56 years)

  16. Second series (01/1995 – 05/2000) • 154 hips • 14 early revisions • 4 late revisions for poly. wear (alumina/poly.)

  17. Survival probability: femoral component n = 154 second series n = 48 pilot study ( Kaplan - Meier ) y

  18. Third series (06/2000 – 11/2005) • 130 hips • Mean age: 42 y. (14-56) • 9 early revisions: • 2 broken ceramic heads (alumina/alumina)

  19. Aseptic necrosis (69 hips)

  20. Aseptic necrosis • From 04/1989 to 02/2003 • 56 patients (50 males/6 females) • 64 hips • Mean age: 49 years (22 – 64) • Mean follow-up: 7 years • 5 revisions • 59 implants still in place

  21. Aseptic necrosis (n: 64) • 5 revisions (7.8%) • Mean age at reoperation: 52 years • Mean time in situ: 3 years • Reasons for revision: • Varus positioning causing pain or loosening (4) • Recurrent dislocation (1)

  22. Aseptic necrosis (n: 64) 59 implants in place: • 1 patient complaining of groin pain (psoas tendinitis?) • 1 late instability (poly. wear) • 2 patients with mild trochanteric pain (screw?)

  23. 7 years 14 years

  24. Need for improved instruments The cutting and drilling guides should be monoblock, in order to avoid rotational mismatch

  25. Conclusions • This experience supports that a purely metaphyseal anchorage of a stemless implant can provide a long lasting fixation • This type of implant is suitable even when the femoral head is destructed • It permits the use of a ceramic on ceramic bearing • It is conservative, as a primary implant can easily be used if revision is needed

More Related