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REVIEW OF CEMENTLESS TOTAL HIP ARTHROPLASTY: 5yr results utilizing a horizontal platform stabilized design

REVIEW OF CEMENTLESS TOTAL HIP ARTHROPLASTY: 5yr results utilizing a horizontal platform stabilized design. THA: Historical. Cemented THA provided marked improvement in fcn for millions of patients 1970’s failure due to loosening of cemented components was first noted

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REVIEW OF CEMENTLESS TOTAL HIP ARTHROPLASTY: 5yr results utilizing a horizontal platform stabilized design

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  1. REVIEW OF CEMENTLESS TOTAL HIP ARTHROPLASTY: 5yr results utilizing a horizontal platform stabilized design

  2. THA: Historical • Cemented THA provided marked improvement in fcn for millions of patients • 1970’s failure due to loosening of cemented components was first noted • This was felt to be one of the most important long term complications of the procedure

  3. THA: Historical • Due to problems with loosening of devices inserted with cement • An alternative method of fixation in which a device could be directly anchored to bone  led surgeons in the U.S. and Europe to further investigate porous coated implants in THA

  4. THA: Historical • 1910 GREENFIELD: dev. Concept of biologic fixation by obtaining a patent for a metallic cage-like framework for the root of an artificial tooth. • 50yrs dedicated to filling soft tissue def. • 1963 SMITH: first to use porous materials for ingrowth (ceramic-plastic composite,pore size 1-25 micrometers)

  5. THA: Historical • 1969 HIRSCHHORN & REYNOLDS: porous coated chromium alloy with powder metallurgy technique • 1969 LUECK: titanium-fiber composite fabricated and implanted • 1970’s to present: stem development has advanced signif. considers: types of coating, pore size,available metals, inhibitors of bone ingrowth designs of implants.

  6. REVIEW: THA cementless • BROAD CATEGORY OF DESIGN TYPES • VARIETY OF BONE TYPES: DORR CLASS • RESTRICT USE BASED ON 1. Pt. age 2. Configuration of medullary canal 3. Specific Bone disease

  7. DORR CLASSIFICATION

  8. REVIEW: THA cementless IN GENERAL: • CEMENLESS STEMS => 1. YOUNGER 75YRS 2. FUNNEL SHAPED PROXIMAL FEMURS 3. ETIOLOGIES: AVN, OA, POST- TRAUMATIC

  9. REVIEW: THA cementless IN GENERAL => CEMENTED STEMS 1. OLDER 75YRS 2. CYLINDRICAL MORPHOLOGY OF PROXIMAL FEMURS 3. ETIOLOGIES: INFLAMMATORY, METABOLIC BONE DISEASE

  10. Lewallen et al.. 1999 CORRSudden Death During Primary Hip Arthroplasty • 38,488 hips in 29,431 patients • 1969-1997 23 intra-operative deaths • 11 cemented THA, 12 cemented Hemi. • Mean age 80.9 • All deaths: irrev. Cardiorespiratory disturbances • Concluded: elderly pts with pre-existing cardiovasc. Conditions undergoing cemented arthroplasty are at increased risk for intraoperative death.

  11. LaPorte, Mont, Hungerford: Review: proximally porous coated Ingrowth Prostheses: limits of Use. Orthopedics 1999

  12. REVIEW: THA cementless • THIGH PAIN => RORABECK REPORTED 6% INCIDENCE USING THE SYNERGY HIP => RANGE IN THE LITERATURE FROM 6-30% => RELATED DIRECTLY TO STEM CHARACTERISTICS AND BONE MORPHOLOGY => THE DEGREE OF POROUS COATING AND STEM STIFFNESS DIRECTLY CORRELATE WITH BONE DENSITY AND ARCHITECHTURE

  13. REVIEW: THA cementless THIGH PAIN -PRESS FIT STEMS HAVE BEEN USED IN DORR TYPE C CYLINDRICAL FEMURS => IMPLANTS HAVE TO BE LARGE IN DIAMETER => CONTRIBUTES TO MODULAR MISMATCH => THIGH PAIN AND STRESS SHIELDING

  14. THA: CEMENTLESS • TYPES OF COATINGS 1. SINTERING 2. DIFFUSION-BONDING 3. PLASMA-SPRAYING

  15. TYPE OF COATINGS: SINTERING • SINTERING: HIGH TEMP. PROCESS WHICH ALLOWS PARTICLE– PARTICLE & PARTICLE-SUBSTRATE BONDING AT CONTACT POINTS • LOWERS FATIGUE STRENGTH • UTILIZED IN COBALT CHROME AND TITANIUM STEMS

  16. TYPES OF COATINGS: DIFFUSION BONDING • RELATIVELY LOW TEMP. • USED IN COMBINATION WITH PREASURE IN MANUFACTURE OF TITANIUM FIBER MESH • WEAKENS STEM DUE TO NOTCH-SENSITIVITY EFFECT

  17. TYPES OF COATING: PLASMA-SPRAYING • PARTIAL MELTING OF METAL POWDERS IN A HOT PLASMA FLAME • DELIVERY OF THE PRODUCT TO THE SUBSTRATE THROUGH A CARRIER GAS UNDER AN APPLIED ELECTRICAL FIELD • LESS INTERCONNECTING POROSITY THAN SINTERED BEAD OR FIBER MESH • ALSO DIMINISHED FATIGUE PERFORMANCE

  18. EVOLUTION OF PRESS FIT DESIGN • THREE BROAD CATEGORIES 1. CYLINDRICAL 2. TAPERED 3. ANATOMIC • TWO GENERATIONS OF EVOLUTION IN DESIGN

  19. FIRST GENERATION CYLINDRICAL • CYLINDRICAL DESIGN DISTALLY • RELY ON STABILITY FROM DISTAL PRESS FIT FIXATION • EXTENSIVELY POROUS COATED • USE MATERIALS OF HIGH STRENGTH • USUALLY COLLARED

  20. SECOND GENERATION CYLINDRICAL • EXTENSIVE SINTERED BEAD POROUS COATING • BETTER PROXIMAL FIT • DISTAL FLUTES • CORONAL SLOTS • POLISHED TIP

  21. FIRST GENERATION TAPERED • LOAD FEMUR PROXIMALLY ONLY • PROXIMALLY COATED • TAPERED AP\MED-LAT • TAPER SELF LOCKING • NO COLLAR

  22. SECOND GENERATION TAPERED • SINTERED BEAD COATING PROXIMALLY INSTEAD OF SINTERED SPRAY • ROTATIONAL RIDGES • POLISHED TIP

  23. FIRST GENERATION ANATOMIC • INCREASED PROXIMAL FIT\FILL FOR STABILITY • ANTEVERTED NECKS • RIGHT AND LEFT CONFIGURATIONS • BOASTS IMPROVED FEMORAL LOADING

  24. SECOND GENERATION ANATOMIC • MOVED AWAY FROM BOWED TIPS => CORR. THIGH PAIN • FLATTENING POSTERIOR AND LATERAL SIDES

  25. HORIZONTAL PLATFORM STABILIZED • LOADS CORTICAL ARC • LATERAL FIN FOR ROTATIONAL STABILITY • T-SHAPED TORQUE RESISTANT CROSS SECTION • STRAIGHT STEM WITH TAPERED TIP

  26. MATERIALS AND METHODS • THIRTY NINE PRIMARY THA WERE RETROSPECTIVELY EVALUATED • ALL PROCEDURE PERFORMED BY ONE SURGEON OR UNDER DIRECT SUPERVISION OF THAT SURGEON • TRANSLATERAL APPROACH WITH MALLORY SPLIT WAS UTILIZED WITH ANATOMIC ABDUCTOR REPAIR

  27. MATERIALS AND METHODS • POST-OPERATIVELY 1. DVT. PROPH WITH LOW DOSE COUMADIN REGIMEN 2. NSAIDS STRICTLY AVOIDED DURING IMMEDIATE POSTOP COURSE 3. POST OPERTIVE REGIMEN WAS IDENTICAL IN ALL CASES WITH FULL WEIGHT BEARING BEGUN FIRST DAY AFTER SURGERY

  28. MATERIALS AND METHODS EVALUATED 1. HSS SCORES AT PREOP, 6WEEKS 6 MONTHS, YEARLY 2. THIGH PAIN VISUAL ANALOG 3. FINAL CLINICAL EVALUATION AT 5YRS

  29. RESULTS • THRTY-EIGHT THA • THIRTEEN PATIENTS DIED • EIGHT RELOCATED UNABLE TO F/U FOR FINAL EVALUATION • SEVENTEEN PTS WITH COMPLETE DATA • MEAN AGE 71.5, RANGE 49-96

  30. RESULTS • 17 PATIENTS at FIVE YRS • 3-AVN ,1- RA ,13-OA • 9 DORR TYPE C, 6 TYPE B, 2 TYPE A • AVE PREOP HSS SCORE 41.6 WITH RANGE 9.9 – 73 • AVE POST-OP HSS 98 , RANGE 81-100 • ZERO PATIENTS HAVE UNDERGONE REVISION • THIGH PAIN RATED ZERO IN 15 PTS AND LESS THAN ONE ON THE PATIENT SURVEY VISUAL ANALOG SCORE IN 2 PTS

  31. CONCLUSIONS • The HPS-II design of press fit stems provides positive results with regard to thigh pain and rates of revision regardless of bone morphology • Elderly patients with type C bone are at greatest risk for intra-operative death related to cementing and are the patients in whom press fitting is ideally suited • The study is limited due to population size but our results are encouraging.

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