B W ll L Be Well Lecture Series: t S i Cutting-edge Joint - PowerPoint PPT Presentation

B W ll L Be Well Lecture Series: t S i Cutting-edge Joint Replacement Cutting edge Joint Replacement Technologies and Advances in Functional Outcomes for Arthritis Patients Patients D David C. Ayers MD id C A MD Patricia Franklin MD, MPH, MBA 1

David C. Ayers, M.D. The Arthur M Pappas Professor & Chair The Arthur M. Pappas Professor & Chair Department of Orthopedics Rehabilitation Director MSK Center of Excellence Director MSK Center of Excellence UMass Memorial Healthcare System Worcester MA Worcester, MA 2

TJR OUTCOME STUDIES TJR OUTCOME STUDIES SHOW • Successful surgical T T K K R R procedure d • Sustained pain relief t o f c h o i c e t a t i n g • Improved physical function o d / e x c e l l e n t • Best QUALY analysis for l l o w - u p ANY surgical procedure • Miracle of modern medicine 3

Be Well Lecture Series: 6-16-10 Be Well Lecture Series: 6 16 10 Joint Replacement Surgery • Introduction • History of total joint replacement • History of total joint replacement • Modern THR; Fixation to skeleton Biologic fixation with porousm Improved UHMWPE; RSA Analysis • Modern TKR High Flexion TKR High Flexion TKR Gender specific TKR 4

TJR Surgery • “ cost effective, reliable treatment for the pain and treatment for the pain and disability of advanced knee and hip arthritis” NIH Consensus Panel 2001 • >600,000 TKR and >375,000 THR in US each year • Is the single largest I th i l l t expenditure of the federal Medicare budget Medicare budget 5

Total Joint Replacement Total Joint Replacement • Prevalence growing in parallel with the aging , ll l ith th i overweight adult US population l ti • 50% over age 65 have diagnosis of arthritis • 60% of women; making it the leading chronic condition among women 6

TJR • Projected growth; more than 600% increase Projected growth; more than 600% increase by the year 2030 • Fueled by aging of the population F l d b i f th l ti • Desire to remain physically active later in p y y life • 35% TJR patients under the age of 65 and • 35% TJR patients under the age of 65 and part of the work force 7

Knee Surgery Most Common Knee Surgery Most Common Surgery in USA 8

Total Joint Replacement Total Joint Replacement • Common operation Common operation for patients with severe arthritis severe arthritis • Severe Pain • Decreased Physical Function Function • All non-operative treatments failed 9

Sir. John Charnley Sir. John Charnley • Wrightington UK • Developed modern Developed modern THR; 1965 • Metal Femoral Head M l F l H d • Teflon, UHMWPE e o , U W Socket • PMMA: Bone Cement PMMA B C t 10

Cemented Charnley THR Cemented Charnley THR • Stainless steel femur • UHMWPE socket • PMMA fixation PMMA fi i 11

• Metal change from M l h f stainless steel to Chrome-cobalt alloy • Modification of Modification of femoral design to increase rotational increase rotational stability • Modular head-neck M d l h d k junction to tension soft tissue/ adjust leg length 12

Implant Geometry: Implant Geometry: Finite Element Analysis • Important contribution to longevity of fixation • Minor design • Minor design changes can greatly effect interface stresses and clinical results 13

• Evaluate stresses at Bone Implant or Bone-Implant or Stem-Cement i interface f • Cement mantle stresses particularly important for important for survival of the i implant l t 14

Surface Finish of Femur Surface Finish of Femur Does it affect fixation? 15

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• Figure 3: Reflected light micro-graph of a 'grit' stem illustrating a well -bonded region of stem/cement interface adjacent to a stem/cement gap. 17

Loosening of Cemented Stems: Effect of Cement Type Effect of Cement Type ( Cox regression with adjustment for gender age systemic ( Cox regression with adjustment for gender, age, systemic antibiotics, operating theatre, prosthesis design, operative approach…Data from Norwegian Registry 2005.) 18

TJR: Fixation to the Skeleton • Replace PMMA PMMA; Cemented TJR • Uncemented d Biologic fixation fi ti • Bone in- growth into th i t porous metal surfaces surfaces 19

C. McCollister Evarts, MD C. McCollister Evarts, MD • Pioneering work in • Pioneering work in Tapered Cementless stems • University of Rochester • Early to mid 1980’s • Early to mid 1980 s 20

Biologic Fixation in THR Biologic Fixation in THR • Has been successfully accomplished in p • Acetabular Components • Femoral Components 21

Biologic Fixation Biologic Fixation • Intimate contact between host bone and the porous p coating • Immediate stability achieved at the time of surgery 22

Biologic Fixation Biologic Fixation • Porous surface of appropriate microstructure pp p • Made from biocompatible material 23

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Bi l Biologic Fixation i Fi ti Ti Prostheses Ti Prostheses 27

Tapered Cementless Stem Tapered Cementless Stem • Based on sound design principles p p • >15 Years of outstanding clinical results 28

Neck Geometry Reduced neck geometry allows for greater ROM g y g M/L Taper M/L Taper M/L Taper vs. Biomet Taperloc Stem vs. Biomet Taperloc Stem vs. DePuy Tri-Lock vs. DePuy Tri Lock vs. Stryker Accolade vs. Stryker Accolade Stem 29

30 Trabecular (Material) (Material) Metal 30% void space 80% Ti Beaded (Coating)

Bone Ingrowth at 6 months Densification and Sealing of Bone at Cortical Rim 31

Polyethylene Bone 32 Trabecular Metal Trabecular Metal Bone in-growth up to poly within TM 6 months in-vivo

RSA RSA • Requires each segment of interest to g be defined by a minimum of three minimum of three and preferably up to nine tantalum i t t l markers 33

RSA Examination RSA Examination • Two x-ray tubes are positioned at 40° p angle to each other • Simultaneous x ray • Simultaneous x-ray exposures are obtained that include a calibration cage g and the THR 34

RSA – Femoral Head Penetration RSA Femoral Head Penetration • Center of femoral head determined by edge detection • 3D motion of this point p can be calculated relative to a rigid body segment g y g • Several software packages developed to packages developed to facilitate this analysis 35

Highly Cross-Linked UHMWPE Highly Cross Linked UHMWPE in THR • Improved UHMWPE • RSA studies here at UMASS show wear reduced significantly reduced significantly • Allows THR in younger and more active patient i • Improve longevity of THR Improve longevity of THR 36

UMASS Excellence in TKR UMASS Excellence in TKR • Gender TKR; made specifically p y for women • High Flexion • High Flexion TKR • Ranawat Award from the Knee from the Knee Society 37

38 FLEXION FLEXION ON ON HIGH- - HIGH TKR TKR TKR TKR

Traditional TKA vs. High Flex TKA g • Designed to safely –Designed to accommodate safely flexion up to 125  t 125  fl i accommodate d t flexion up to • Global cultural and 155  155 religious activities < 125  –Global, cultural and religious d li i activities to 155  39

Keys to high flexion Keys to high flexion • Patient selection • Surgical technique • Surgical technique • Implant design p g • Rehabilitation 40

Patient selection Patient selection • Activity level – Ability and desire for high y g flexion • Best indicator of post op • Best indicator of post-op flexion is pre-op flexion • Compliance with rehabilitation program p g 41

ANATOMY: Cartilage N O : Ca age CARTILAGE ARTICULAR CARTILAGE MEDIAL LATERAL MENISCUS MENISCUS ARTICULAR ARTICULAR CARTILAGE 42

Arthroscopic Knee Surgery Arthroscopic Knee Surgery • Out-patient • Small portals Small portals • Correction of meniscus tears, i loose bodies • Does not change arthritis change arthritis 43

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46 ARTHROSCOPIC VIEW MENISCUS MENISCAL TEAR MENISCAL MENISCAL TEAR Meniscus Normal

47 Treatment of Degenerative MENISCAL TEARS MENISCAL TEARS TORN SEGMENT REMOVED REMOVED TEAR

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Unicompartmental Unicompartmental Knee Replacement Knee Replacement 54

Younger Patients Younger Patients • More reasonable to do joint replacement with current options available p • Now an option for patients in 50’s • Any age in inflammatory arthritis A i i fl h i i • Patients should limit their activities to at e ts s ou d t t e act v t es to maximize the life-span of their replacement – no high impact activities no high impact activities 55

The “New Patient” The New Patient • Younger Y • More active • More educated • More • More informed • Heavier H i • More #’s 56

57 THANK YOU! THANK YOU!