The document summarizes recent developments in total hip replacement surgery. It discusses the direct anterior surgical approach, concerns about metal-on-metal implants including pseudotumors and elevated metal ion levels, outcomes of hip resurfacing, developments in stems, cups and bearings, the use of rivaroxaban for DVT prophylaxis, and the utility of the leukocyte esterase test in diagnosing periprosthetic joint infection.

1. CURRENT STATUS OF TOTAL HIP
SURGERY
WHAT IS NEW???
ANTHONY S UNGER, MD
WASHINGTON, DC

2. WHAT’S NEW

3. THA 2012
 SURGICALAPPROACH
 METAL ON METAL
 SURFACE REPLACEMENT
 STEMS
 CUPS
 BEARINGS
 DVT PROPHYLAXIS
 INFECTIONWORK UP

4. SURGICAL APPROACH
THE
DIRECT
ANTERIOR
APPROACH

5. DAA ADVANTAGES
 PATIENT SUPINE—LL EQUALIZATION
 LOWER DISLOCATION RATE
 LESS INVASIVE ?
 OBESE PATIENTS EASIER
 LESS DVT??—LESS KINKING OF FEMORAL
VEIN

6. DAA-TABLE-LESS
 ADVANTAGES
 QUICKER, LESS SET UP
 BETTER ASSESSMENT OF STABILITY
 CHEAPER—NOTABLE COSTS
 BETTER ABILITYTO EQUAL LL
 DON’T NEED XRAY

8. Creatine Kinase Differences between
Anterior and Posterior MISTHA
5.5X 1.4X 1.8X

9. DAA-TABLE-LESS
 QUICKER RECOVERY, MORE BLOODLOSS??
 BEREND ET AL, JBJS, 2009
 DAA vs DL IMPROVED HARRIS HIP SCORE AND
LOWER EXTACTIVITY @ 6WKS
 HIGHER RATE OF D/CTO HOME
 INCREASED BLOODLOSS(155CC VS 130 CC)?

10. DAA-TABLE-LESS
 BETTER FUNCTIONAL SCORES
 RESTREPO ET AL, J OF A, 2010
 PROSPECTIVE FUNCTIONAL OUTCOMES OF
DAAVERSUS DIRECT LATERAL
 UPTO 2YRS DAA HAD BETTER FUNCTION
SCORES ON SHORT SF-36 ANDWOMAC

11. METAL ON METAL

12. MOM
WARNINGS
 BRITISH ORTHOPAEDIC SOCIETY AND
BRITISH HIP SOCIETY 2010
 YRLY XRAY AND CLINICAL EVAL
 METAL IONS, MARS/CT IN SYMPATOMATIC PTS
 REPEATTESTING FOR ELEVATED ION
LEVELS(>7PPB)
 ENDORSED BY US FDA, AAOS, AAHKS, HIP
SOCIETY

13. METAL ON METAL
 EFFECT OF ELEVATED METAL IONS NOT
UNDERSTOOD
 EFFECT OF FEMORAL HEAD SIZE ON ION
LEVELS SHOW CONFLICTING RESULTS
 CLINICALTRIALS COMPARING MOMTO
OTHER BEARINGS USING RANDOMISED
CONTROLS LACKING
 MALVIYA, A. ET AL, JBJS 92:1675, 2010

14. METAL ON METAL
 PSEUDOTUMORS
 MARS STUDY(METALARTIFACT REDUCTION
MRI)
 17/30(57%) IN PAINFUL MOM
 17/28(61%) IN NON PAINFUL MOM
 “COMMON INWELL POSITIONED IMPLANTS”
 HART, A. J. , JBJS 94:317, 2012

15. METAL ON METAL
 PSEUDOTUMORS
 ULTRASOUND- MOMVS MOP
 42% IN MOMTHA
 25% IN MOM SRA
 12% IN MOP
 ION LEVELS DID NOT CORRELATE
 WILLIAMS, D.H ET AL, JBJS 93:2164, 2011

16. AAOS
MOM TECH UPDATE 2011
 #1 WHAT ARE CLINICAL OTCOMES OF MOM
THAVS OTHER BEARINGS??
 PTSWITH MOM HAVE GREATER RISK OF REVISION
 #2WHAT ARETHE PT FACTORSTHAT BEST
PREDICT SUCCESS OF MOM?
 LARGE HEAD IN MOMTHA INCREASE REVISION
 SMALL HEAD SIZE IN MOM SRA INCREASE
REVISION
 PTS OLDERTHAN 65 HAVE HIGHER REVISON RATE
 NO GENDER DIFFERENCES

17. MOM
AAOS TECH UPDATE 2011
 #3WHAT IS PREVELANCEOF CLINICAL
PROBLEMSWITH MOMTHA COMPAREDTO
OTHER BEARINGS??
 MALPOSITIONED IMPLANTS HAVE HIGHER
FAILURE RATES AND ELEVATED IONS
 CLINICAL SIGNIFICANCE OF ELEVATED IONS
UNKNOWN

18. MOM HIP WORK UP
 GET XRAYS, EXAMINE PT
 LOOK FOR MECHANICAL FAILURE
 KNOW RECALLS(ASR, DUROM)
 LOOK FOR ABNORMAL ANTERVERSION OR
HIGHADB ANGLE
 MEASURE IONS(>5-7 PPb)
 REVISE IF PAINFUL
 DO MARS MRI OR ULTRASOUNDTO LOOK
FOR PSEUDOTUMORS

19. SURFACE REPLACEMENT

20. HIP RSURFACING(SRA)
 1.4-3.6 INCREASED REVISION RATE
COMPAREDTOTHA
 MCGRORY ET AL 2011
 REVISION RATE 3.5% IN 29 STUDIES, 10625
SRAS
 VAN DERWEEGEN ET AL, 2011

21. HIP RESURFACING (SRA)
 AMSTUTZ ET AL 2010
 10YR SURVIVAL 88.6% IN 100 CONSECUTIVE
SRA
 NO FAILURE IN HEAD SIZE >46MM
 TREACY ET AL 2011
 10YR SURVIVAL 95.5% IN 144 HIPS
 98% SURVIVAL IN MALES

22. SRA
AAOS TECH OVERVIEW 2009
 #1 ARE REVSION RATES DIFFERENT FOR
SRAVSTHA?
 ANALYSIS OF 3 REGISTRIES –SRA>REVISION
RATETHANTHA
 #2WHAT CHARACTERISTICS FOR PTSWITH
SRA GIVE BEST OUTCOMES?
 NO CONCLUSIONS

23. SRA
AAOS TECH OVERVIEW 2009
 #3WHAT IS MORE EFFECTIVETX SRA OR
THA??
 LIMITED DATA, NO CONCLUSIONS
 #4 ISTHERE EVIDENCETHAT EXPERIENCE
IMPROVES OUTCOME??
 LOW QUALITY STUDIES SUGGEST EXPERIENCE
IMPROVES OUTCOMES

24. STEMS

25. THA-Stems

26. THA-STEMS

27. THA-Stem

28. CUPS

29. THA-Ceramics

30. THA-Ceramics

31. BEARINGS

32. Cross-linking and Free Radicals
C C C C C
H H H H H
H H
C
H
H * H
C
H
H
C C C
H H
H H H
C
*
C
H
H H
C
H
H
C
H
H
Cross-link
 Irradiation forms free radicals and crosslinks
 Heating forms more crosslinks and eliminates free radicals
Free
Radicals
This information is provided for internal use only and is not intended for general distribution or use. Product availability is subject to the regulatory or medical practices
that govern individual markets. Please contact your Stryker representative if you have any questions about the availability of Stryker products in your area.

33. Crosslinking Decreases Wear
Reference (7)
This information is provided for internal use only and is not intended for general distribution or use. Product availability is subject to the regulatory or medical practices
that govern individual markets. Please contact your Stryker representative if you have any questions about the availability of Stryker products in your area.

34. CROSS-LINKED POLY
 WEAR RATE .003VS .051 MM/YR
 95% IMPROVEMENT
 FU AT 6.8YRS
 MEN AS GOODASWOMEN
 50YR HIP???
 Mc CALDAN ET AL JBJS, 2009

35. DVT PROPHYLAXIS-XARELTO

36. Xarelto(rivaroxaban)
 Xa inhibitor
 RecordTrial
 THA 30 days, 10 mg/day
 TKA 14 days, 10 meg/day
 Lower DVT than Lovenox
 No more bleeding
 Cheaper
 Use in high risk pts??

37. INFECTION WORK UP

39. Leucocyte Esterase
 Scientific Articles | December 21, 2011
 Diagnosis of Periprosthetic Joint Infection:The
Utility of a SimpleYet Unappreciated Enzyme
 Javad Parvizi, MD, FRCS1; Christina Jacovides,
BS1;Valentin Antoci, MD, PhD1; Elie Ghanem,
MD1
 1 Rothman Institute of Orthopedics atThomas
Jefferson University Hospital, 925 Chestnut
Street, Philadelphia, PA 19107. E-mail address
for J. Parvizi: research@rothmaninstitute.com

40. Leukocyte Esterase
 Results: On the basis of clinical, serological, and operative
criteria, thirty of the 108 knees undergoing revision
arthroplasty were infected and seventy-eight were
uninfected.When only a ++ reading was considered
positive, the leukocyte esterase test was 80.6% sensitive
(95% confidence interval [CI], 61.9% to 91.9%) and 100%
specific (95%CI, 94.5% to 100.0%), with a positive
predictive value of 100% (95%CI, 83.4% to 100.0%) and a
negative predictive value of 93.3% (95% CI, 85.4% to
97.2%).The leukocyte esterase level correlated strongly
with the percentage of polymorphonuclear leukocytes (r =
0.7769) and total white blood-cell count (r = 0.5024) in the
aspirate as well as with the erythrocyte sedimentation rate
(r = 0.6188) and C-reactive protein level (r = 0.4719) in the
serum.

41. THANKYOU