1. OSTEONECROSIS OF THE FEMORAL HEAD: Modern Results of Total Hip Arthroplasty Daniel J. Berry, MD Prof and Chairman Mayo Clinic Rochester, MN

2. OSTEONECROSIS: THA Introduction Advantages of THA: THA is the one form of treatment for osteonecrosis with an extremely high likelihood of excellent pain relief and good function

3. OSTEONECROSIS: THA Results What are the results of THA in the osteonecrosis patient population?

4. OSTEONECROSIS: THA Results Pain Relief and Function: Good Similar pain relief and function to THA for other diagnoses

5. OSTEONECROSIS: THA Results Pain Relief and Function: THA provides more complete/ reliable pain relief than hemiarthroplasty or head sparing procedures Ito et al, CORR 2000 Cabanela, CORR 1990

6. OSTEONECROSIS: THA Results THA Durability in osteonecrosis: The most controversial topic when discussing THA for osteonecrosis

7. OSTEONECROSIS: THA Results Difficult to disentangle the fact that most osteonecrosis cohorts have high frequency of demographic factors and underlying diagnoses that put them at risk for implant loosening and wear

8. OSTEONECROSIS: THA Results Osteonecrosis patients frequently young and active Osteonecrosis includes very high activity subgroups; e.g. post-traumatic

9. OSTEONECROSIS: THA Results Durability: Literature One body of literature: THA for osteonecrosis less durable (loosening/lysis) than THA for osteoarthritis Another body of literature: little difference in durability between THA for osteonecrosis and other diagnoses Ortiguera et al, J Arthrop, 1999 Sarmiento et al, JBJS(A), 1990 Chiu et al, J Arthrop, 1997Mont, Hungerford, JBJS(A) 1995 Xenakis et al, CORR, 1997

10. THA FOR OSTEONECROSIS Uncemented THA These are historical results What are the results with more modern techniques?

11. THA FOR OSTEONECROSIS New Mayo Series 98 uncemented THA 1991-2000 60 male, 38 female Mean age 37 years Mean F/U 6 yrs Guyen, Cabanela, Berry, 2005

12. THA FOR OSTEONECROSIS New Mayo Series All treated with uncemented HA coated tapered stem 28 mm head on conventional PE

13. THA FOR OSTEONECROSIS New Mayo Series Re-operations for aseptic femoral or acetabular loosening: 0/98 = 0%

14. THA FOR OSTEONECROSIS New Mayo Series Re-operations for bearing wear/osteolysis: 8/98 = 8%* * all had conventional PE bearing

15. OSTEONECROSIS: THA Results Literature comparison: Good results with other successful uncemented designs* - extensively porous coated femoral implants** - successful tapered uncemented stems*** * Xenakis et al, CORR 1997 ** Piston et al, JBJS(A) 1994 ***D’Antonio et al, CORR 1997

16. THA FOR OSTEONECROSIS Lessons Learned Modern uncemented THA is outperforming historical results of cemented THA osteonecrosis patients The fixation results are comparable to uncemented THA for other diagnoses

17. THA FOR OSTEONECROSIS Lessons Learned Wear and osteolysis rates in this young patient group are unacceptable with conventional PE bearing surface Alternative bearings (ceramic, metal, crosslinked PE) are justified

18. THA FOR OSTEONECROSIS Dislocation Risk Are osteonecrosis patients at higher risk for dislocation?

19. LONG TERM DISLOCATION RISK Materials and Methods All primary Charnley THA performed at Mayo Clinic 1969-1984 6623 hips JBJS (A), Jan 2004

20. OSTEONECROSIS: THA Complications Dislocation risk is elevated in AVN population Years after surgery AVN DJD Cumulative probability of dislocation (%)

21. LONG TERM DISLOCATION RISK Results Risk of Dislocation (Compared to Osteoarthritis) Factor Relative Risk (CI) Dx=Osteonecrosis 1.9 (1.1-3.2) p<0.01

22. OSTEONECROSIS: THA Complications Literature: Dislocation rate also high in other series: compliance problems in subgroups of patients (EtOH) less capsular hypertrophy in osteonecrosis than osteoarthritis

23. THA FOR OSTEONECROSIS Lessons Learned Instability risk elevated in osteonecrosis: Efforts to minimize instability justified -anterior approaches or -posterior approach with capsular repair -larger head size (≥ 32 mm)