Disclosure - Amazon Web Services · PDF file · 2015-11-09Disclosure •Consultant - Smith and Nephew, ... ASA Physical Status Classification System ASA Relative Value Guide®

11/4/2015

1

•James E. Wood , MD•Medstar Harbor Hospital

•Baltimore, Maryland

Outcast to OutpatientZUK Unicompartmental ReplacementHistory and Indications

Disclosure

• Consultant - Smith and Nephew, Zimmer

2

The New Arthritic Patient

• Younger

• More active

• Greater expectations

• Increasing life expectancy

• Loads of them!!

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2

Prevalence of Unicompartmental

Arthritis

Some Differing Opinions

• 13% of the patient population2

• 26% of the patient population2

• 47.6% of the patient population1

1. Willis-Owes et al. Unicondylar knee arthroplasty in the UK National Health Service: an analysis of

candidacy, outcome and cost efficacy. Knee. 2009 Dec;16(6):473-8. Epub 2009 May 22

2. Schindler et al. The practice of unicompartmental knee arthroplasty in the United Kingdom. J

Orthop Surg (Hong Kong). 2010 Dec;18(3):312-9.

11/4/2015

3

2015

The Rise of UKA (1970’s)

• Introduced in the US in

the1970’s (Marmor)

– Same incision and “similar”

recovery time as TKA

– Considered short-term

repair/alternative to HTO

• Gained popularity quickly

The Fall of UKA-1980’s

• Initial enthusiasm also brought new

designs

• 1980’s reports of poor results and high

failure rates (loosening, progressive

arthritis opposite compartment, poly

wear)

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loosening Opposite compartment

degeneration

Loose, poor technique, uncemented


• Laskin JBJS 1978

• Insall and Aglietti JBJS 1980

– Contra-lateral compartment failures

noted at 4-7 years (all knees over

corrected)

– Femoral and tibial loosening due to

constraint, poor design and

inadequate instrumentation

• “Little to no indication for UKA”• Unicondylar Knee

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5


Total Knee Universal Instruments

Kenna, Hungerford and Krackow:

“tools based on the anatomical concept of measured

resection ”

UKA fell to less than 1% of US Knee market

Goals of AlignmentKennedy and White, CORR 1985

• Avoid overcorrection

to protect the opposite

compartment

• Slight residual

mechanical

varus/medial,

valgus/lateral

Indications

• Kozinn & Scott: (JBJS 1989) “Ideal” patient

(Widely accepted as absolute criteria)

No inflammatory arthritis

Unicompartmental disease

Flexion contracture<5

Angular deformity<15

Age > 60, Low activity

Weight < 180 lb.

Intact ACL

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6

Anteromedial Osteoarthritis of the Knee:

The Ideal Uni Knee

S.H White, P.F Ludkowski, J.W. Goodfellow

J Bone Joint Surg (Br) 1991;73-B: 582-6

Benefits of UKA over TKA in

appropriate patients

• Less blood loss, better ROM, kinematics1

• UKA preferred over TKA by patients2

• Significantly lower risk of infection and other

medical complications3

• Improved function and return to higher level

activities with UKA vs. TKA4

• UKA is currently underused procedure

worldwide (could be as high as 20-50%!!!)5

1. Rougraff et al 1991, 2.Cobb et al 1990, 3.Knutson et al 1990, 4. Laurencin et al 1991, 5. Willis-

Owen et al 2009, Arno et al 2011, Pandit et al 2011

MG UKA • Released 1988

• Creative new design: unconstrained,

precision instrumentation, flexion gap

decompression, frontal plane alignment

• Training affect

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7

History of UKA late 1990’s

Advent of mini-arthrotomy

Repicci (1997)

Zimmer introduces new MIS

instruments

IM (Albrektsson 1998)

EM (Williamson1999

Spacer block (2000)

Increase UKA: USA

1998: 6570

2005: 44990

8% OF KNEE

ARTHROPLASTY

McGlynn et al, The Journal of Arthroplasty, Vol. 23, No. 3, 2008.

Positive Results: M/G

…UKA is Viable Arthroplasty Option

No Longer Viewed as a Temporary Fix…

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8

UKA Today

22,700 Unit Growth from 2009 - 2013

8.8% Annual Growth – 2x TKA

Millennium Research

Wood UKA Fixed Bearing Series 1/2002 to

12/2009

310(pts), 375(knees)

• Male: 120 (32%), Female: 255 (68%)

• Age: 36 – 96 yrs (Mean:63.1)

• <65yrs(49%), =/>65yrs (51%)

• Medial: 290(76.8%), Lateral: 85(23.2%)n = 375

Yearly Cumulative Percent Revision of Primary

Knee Replacement - Australian Registry 2009

Type 1yr 3yrs 5yrs 7yrs

Total Knee 1.0

(1.0, 1.1)

2.8

(2.8, 2.9)

3.8

(3.6, 3.9)

4.6

(4.4, 4.7)

Unicompartmental 2.2

(2.1, 2.4)

6.2

(5.9, 6.5)

8.8

(8.4, 9.2)

11.9

(11.3, 12.5)

ZUK 1.0

(0.6, 1.9)

2.6

(1.5, 4.3)

- -

Wood 1.4

(1.1, 1.6)

2.9

(2.6, 3.0)

4.2

(4.0, 4.5)

4.8

(4.5, 4.9)

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BMI kg/m2 FREQUENCY MEAN BMI

kg/m2

Revision

<18.5

(underweight)

3 18.4 0

18.5-24.99

(normal weight)

43 23.1 3

25-29.99

(overweight)

100 27.2 4

30-34.99

(mild obesity)

101 32.4 5

35-39.99

(moderate obesity)

68 37 3

>40

(morbid obesity)

60 45.6 5

Total 375 - 20

BMI and Revision: Wood

Patient Selection: UKA

• Well functioning knee with pain

• Non inflamatory arthritis

• Pain localized and increased with activity

• Normal soft tissue envelope:

– Near full range of motion

– Correctible deformity

– Stable knee

• Corroborating x-ray, tests and findings at

surgery of primarily unicompartmental

disease

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10

Stress View

UKA Success

1. Patient Selection

2. Implant Design

3. Streamlined /

Reproducible

Surgical Technique

Identifying the Outpatient

Candidate

ASA Physical Status Classification

System

ASA Relative Value Guide® (ASA Relative Value Guide). Source: ASA Website 6/23/12. Relative Value Guide® is a registered trademark of the American Society of Anesthesiologists, Inc.

https://ecommerce.asahq.org/p-369-2011-relative-value-guidesupregsup-package.aspx

11/4/2015

11

ASA Physical Classification

System– ASA Physical Status 1 - A normal healthy patient

– ASA Physical Status 2 - A patient with mild systemic disease

– ASA Physical Status 3 - A patient with severe systemic disease

– ASA Physical Status 4 - A patient with severe systemic disease that

is a constant threat to life

– ASA Physical Status 5 - A moribund patient who is not expected to

survive without the operation

– ASA Physical Status 6 - A declared brain-dead patient whose organs

are being removed for donor purposes

These definitions appear in each annual edition of the ASA Relative Value Guide® (ASA Relative Value Guide). There

is no additional information that will help you further define these categories. Source: ASA Website 6/23/12. Relative

Value Guide® is a registered trademark of the American Society of Anesthesiologists, Inc.

Contraindications for OP Surgery

Patients with any of the following may not

qualify for OP UNI procedure:

• COPD

• CAD

• CHF

• Cirrhosis

Lee, Gwo-Chin, et al. Who Should Not Undergo Short Stay Hip and

Knee Arthroplasty? Risk Factors Associated with Major Medical Complications Following

Primary Total Joint Arthroplasty. JOA 30 suppl.: 1 (2015) 1-4

Case

• 58 yo female USTA Team Captain

• 230 lbs 5ft 5in BMI: 38.3

• Medial knee pain, specific

• Arthroscopic partial medial menisectomy 3

yrs ago

• Multiple steroid injections/ celebrex

• Unloader brace

• 2 rounds of hyaluronic acid injections

• Can ambulate ½ mile with moderate pain

• ROM full; correctible deformity

• Played tennis 4 days/week – now unable

https://ecommerce.asahq.org/p-369-2011-relative-value-guidesupregsup-package.aspx

11/4/2015

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Treatment Choice

11/5/2015

1

Kevin Fricka, MDAnderson Orthopaedic Clinc

Alexandria, VA

Outcast to OutpatientZUK Unicompartmental ReplacementAn Overview of clinical evidence

Disclosure• Consultant - Smith and Nephew, Zimmer, OrthoCareRN

• Research funding - Zimmer, Inova

• Institutional study funding - Zimmer, Smith & Nephew,

Depuy, Inova, Biomet

• ASC surgeon owner,

• Surg Center Development:

2

UKA Success

1. Patient Selection

2. Implant Design

3. Streamlined / Reproducible Surgical Technique

4. Proven Track Record

3ZUK Success

11/5/2015

2

“Let’s just do a total knee”

• App 30% of patients who get TKA could have gotten a UKA

• App 20% of patients are DISSATISFIED with their TKA

• Failure rates are HIGHER in younger patients…

4

Benefits of UKA over TKA in

appropriate patients

• Less blood loss, better ROM, kinematics1

• UKA preferred over TKA by patients2

• Significantly lower risk of infection and other medical complications3

• Improved function and return to higher level activities with UKA vs. TKA4

• UKA is currently underused procedure worldwide (could be as high as 20-50% of your TKAs!!!)5

51. Rougraff et al 1991, 2.Cobb et al 1990, 3.Knutson et al 1990, 4. Laurencin et al 1991, 5. Willis-

Owen et al 2009, Arno et al 2011, Pandit et al 2011

Recent UKA Growth

6

9

22,700 Unit Growth from 2009 - 2013

8.8% Annual Growth – 2x TKA

Millennium Research

11/5/2015

3

ZUKAn Overview of clinical

evidence 7

FOR INTERNAL USE ONLY

3842

531

4932

416407

10,128

ZUK

2135

710

2363

118

1596

6,922

Australia New Zealand England, Wales and N. Ireland RIPO Sweden*

Data sources: The latest annual reports of each registry* The Swedish Knee Arthroplasty Register reports the risk of device revision only as it relates to another implant (Link), and is therefore of

limited value for judging performance in this presentation

ZUK and MG clinical data

Number of knees tracked registry data (latest reports)

MG


0.

5.

10.

15.

20.

25.

1y 3y 5y 7y 10y 13y

UKA, class avg MG ZUK

Aim:

to be BELOW

the class average

Cu

mu

lative p

erc

en

tag

e r

evis

ion

(CP

R)

Time of follow up (years)

0.

5.

10.

15.

20.

1y 3y 5y 7y 10y 13y

Oxford 3

(tibial:

Oxford 3)


Australian registry data (2014 report)

Source: Australian Orthopaedic Association National Joint Replacement Registry. Annual report. Hip and Knee Arthroplasty

September 1999 to December 2013. 2014.

Cumulative percent revision (CPR) : Measures the total percentage of devices that failed/required revision at a given time point

Class average

(10.8)

MG (8.1)

ZUK (5.8)

Oxford 3 (11.2)

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Registry data: Australian 2015

10

According to 2015 AUS Registry data


0.

5.

10.

15.

20.

25.

1y 3y 5y 7y 10y 13y

UKA, class avg MG ZUK


England, Wales & N. I. registry data (2014 report)

Aim:

to be BELOW

the class average

Cu

mu

lative p

erc

en

tag

e r

evis

ion

(CP

R)

Time of follow up (years)

1y 3y 5y 7y 10y

Oxford

Cumulative percent revision (CPR) : Measures the total percentage of devices that failed/required revision at a given time point

Source: National Joint Registry for England, Wales and Northern Ireland: 11th Annual Report. 2014.

Class average (9.1)

MG (7.4)

ZUK (5.4)

Oxford 3 (8.8)


1.27

0.94

0.74

0.

0.325

0.65

0.975

1.3

1.625

1


New Zealand registry data (2014 report)

Total observed years

Revis

ion

s p

er

10

0 o

bserv

ed c

om

pon

en

t years

(R

ev/1

00

OC

Y)

ZUK

1,477

MG

5,626

Class Avg

46,383

Aim:

to be

BELOW

the class

average

Source: New Zealand Orthopeadic Association: New Zealand Joint Registry 15 Year Report. 2014. Revisions per 100 OCYs: The rate of prostheses revised for every 100 OCYsObserved component years (OCYs): The total number of years since device implantation (e.g., 5 people who have had UKA implanted for 1 year each would add up to 5 OCYs)

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5


1.27

0.94

0.74

0.

0.325

0.65

0.975

1.3

1.625

1


New Zealand registry data (2014 report)

Total observed years

Class Avg

46,383

MG

5,626

ZUK

1,477

Revis

ion

s p

er

10

0 o

bserv

ed c

om

pon

en

t years

(R

ev/1

00

OC

Y)

Observed component years (OCYs): The total number of years since device implantation (e.g., 5 people who have had UKA implanted for 1 year each would add up to 5 OCYs)Revisions per 100 OCYs: The rate of prostheses revised for every 100 OCYs. | Source: New Zealand Orthopeadic Association: New Zealand Joint Registry 15 Year Report. 2014.

1.37

0.72

Oxford3

26,005

Oxford3uncemented

5,033


93.3

88.6

96.6

94.2

95.5

82.

85.

88.

91.

94.

97.

100.

1 2


RIPO registry data (2015 report)

5y

Impla

nt

su

rviv

ors

hip

(%

)

Time of follow up (years) 10y

UKA, class avg M/G ZUK

Aim:

to be

ABOVE

the class

average

Implant survivorship: Estimates the probability that each individual has of maintaining a prosthesis in place over time

Source: Register of Orthopedic Prosthetic Implantology (RIPO): Annual Report from the Emilia-Romagna Region of Italy. 2015.


93.3

88.6

96.6

94.2

95.5

82.

85.

88.

91.

94.

97.

100.

1 2


RIPO registry data (2015 report)

5y

Impla

nt

su

rviv

ors

hip

(%

)

Time of follow up (years) 10y

91.7

75.

100.

1

87

75

100

1

UKA, class avg M/G ZUK

Oxford

Implant survivorship: Estimates the probability that each individual has of maintaining a prosthesis in place over time

Source: Register of Orthopedic Prosthetic Implantology (RIPO): Annual Report from the Emilia-Romagna Region of Italy. 2015.

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6


16

2008 New Zealand Joint Registry 1 Pain 37%

2 Loosening 35%3 Progession of Arthritis 7%

4 Bearing Dislocation 6%

5 Infection 4%

2008 Norwegian Arthroplasty Register 1 Pain 34%

2 Loosening 34%3 Malalignment 6%

4 Defect Polyethylene 5%

5 Instability 5%

2009 Swedish Arthroplasty Register 1 Loosening 38%

2 Progression 28%3 Wear 13%

According to the Registries, 34-38% of all revisions

are due to pain and component loosening1,2,3

Uni failure modes

Revision Rates: UKA vs. TKA Swedish Knee Registry, 2007

17

5% at 10 years 10% at 10 years

? UKA and Early Revisions

18

< 2% at 5 years > 5% at 5 years

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7

Experience is Important

for UKA Survivorship

< 10% of knee arthroplasties

in the U.S. are UKAs

Is there a threshold for doing UKAs?

19

Surgeon Experience

Does Make a Difference

20

We can’t compare survivorship

of UKA & TKA?

• Surgeon experience: New Surgical

Technique

• Patient demographics: Age & Gender

Distribution

• Disease process: OA vs. RA

• Surgeon bias for revision

21

11/5/2015

8

? Survivorship

& Patient Demographics

? different patient populations

- Male/Female ratio

- Age distribution

- Disease process: OA vs. RA

Younger, males & OA have higher failure

rates

22

Patient Demographics

Age Distribution (N=3569)Australian Knee Registry, 2006

Age Under 65 65 and

older

UKA 50 % 50 %

TKA 31 % 69 %

Age has a considerable effect

on the rate of revision both in TKA and

UKA. 23

Age Distribution: UKA

Swedish Knee Registry, 2007

24

Medial UKA

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9

TKA Revision Rates (Adjusted for Age)

25

Patient Demographics

Usage of Unicompartmental Knee

Replacement by Gender

Female Male

UKA 50 % 50 %

TKA 60 % 40 %

No RAs in UKA group

Australian Knee Arthroplasty Registry, 2006

Swedish Knee Arthroplasty Registry, 2007

26

? Surgeon Bias for Revision

Surgeons are:

hesitant to revise a painful TKA

without a known cause

But.......

quick to revise a painful UKA

without a known cause.

27

11/5/2015

10

Painful Arthroplasty Algorithm

Painful TKA Painful UKA

Reason known Reason unknown Reason known Reason unknown

Revise Don’t Revise Revise Revise

10% with

unexplained pain

UKA vs. TKA

• 102 prospective randomized knees

• FU: 60 months

• Higher % of excellent clinical scores

and > ROM with UKAs

• Similar survivorship

Newman et al, JBJS 80B, 1998 29



Literature data Overview of all published studies*

ZUK MG

17 25

0.8 – 6.8y 2.8 – 20y

6 – 471 5 – 2,330

Number of studies

Range of mean follow-up

Sample size range

1,030 3,442

Number of knees tracked in

literature

*See reference lists: all clinical studies

11/5/2015

11



Literature data Overview of studies analyzed*(Studies that provide outcomes of interest: survival, revision, and/or clinical outcome scores)

ZUK MG

11 20

0.8 – 6.8y 2.8 – 20y

12 – 471 28 –

2,330

Number of studies

Range of mean follow-up

Sample size range

819 3,146

Number of knees tracked in

literature

*Data from these studies are presented in the next slides



Kaplan-Meier Survivorship(Revision for any reason or radiographic loosening)

0.

25.

50.

75.

100.

1y 2y 3y 4y 5y 6y 7y 8y 9y 10y 11y 12y 13y 14y 15y 16y

Geller Column2

Kapla

n-M

eie

r S

urv

ivors

hip

’

Years follow up

Kaplan-Meier (KM) survivorship: Estimates the probability that each individual has of maintaining a prosthesis in place over time

Bell, 2014 (n = 44) | 100 (2y)

Biswas, 2013 (n = 85) | 96.5 (10y)

Geller, 2011 (n = 30)* | 89.7 (2y)

Vasso, 2015 (n = 125) | 98.4 (6.8y)

ZUK

* Reason for revision not defined in study



Kaplan-Meier Survivorship(Revision for any reason or radiographic loosening)

Kapla

n-M

eie

r S

urv

ivors

hip

’

Years follow up

0.

25.

50.

75.

100.

1y 2y 3y 4y 5y 6y 7y 8y 9y 10y 11y 12y 13y 14y 15y 16y

Geller Column2

Kaplan-Meier (KM) survivorship: Estimates the probability that each individual has of maintaining a prosthesis in place over time

Argenson, 2013 (N =160) | 94 (10y); 83

(15y)

Berger, 2015 (N =51) | 98; (10y) 95.7

(13y)

Geller, 2013 (N =34)* | 97.1 (2y)

John, 2011 (N =94) | 94 (10y); 87 (15y)

Naudie, 2004 (N =113) | 94 (5y); 90 (10-

14y)

Parratte, 2009 (N =35) | 80.6 (12y); 70

(16y)

Pennington, 2003 (N =46) | 92 (11y)

Whittaker, 2010 (N =150) | 96 (5y)

MG

11/5/2015

12



Reasons for revisions

0. 1.3 2.5 3.8 5.

Retained PMMA

PE wear

Injury/traumatic instability

Aseptic loosening

Unknown/not reported

Infection

Fracture

Pain

Arthritic progression*0. 1.3 2.5 3.8 5.

ZUK MG

Percentage revision (in all studies)

N = 790 N = 290



Knee Society Scores (clinical)

49.551.5

92.3 92.5

0.

25.

50.

75.

100.

1 2ZUK

Kn

ee S

ocie

ty S

core

(clin

ical)

pre-op post op

MG

Knee Society Score (KSS): A widely used outcome score for measuring post-arthroplasty function, with scores ranging from 0 (worst) to 100 (best)

Knee Score (or Clinical score): considers pain, stability, and range of motion (ROM)

The mean scores

given are not

weighted to

account for follow-

up times.

Benchmark*

*A score equal or above the benchmark (80-100) is considered an indication of excellent outcome

(Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of the Knee Society clinical rating system. Clin Orthop Relat Res. 1989

Nov;(248):13-4).

No. studies reporting =

4 (ZUK); 3-6 (MG)



Knee Society Scores (functional)

48.951.5

88.884.6

0.

22.5

45.

67.5

90.

112.5

1 2ZUK

Kn

ee S

ocie

ty S

core

(clin

ical)

pre-op post op

MG

Knee Society Score (KSS): A widely used outcome score for measuring post-arthroplasty function, with scores ranging from 0 (worst) to 100 (best)

Knee Score (functional): considers walking distance, stair climbing, and deduction in use of a walking aid

The mean scores

given are not

weighted to

account for follow-

up times.

Benchmark*

*A score equal or above the benchmark (80-100) is considered an indication of excellent outcome

(Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of the Knee Society clinical rating system. Clin Orthop Relat Res. 1989

Nov;(248):13-4).

No. studies reporting =

4 (ZUK); 3-5 (MG)

11/5/2015

13



Hospital of Special Surgery score

60.8

93.1

0.

25.

50.

75.

100.

preMG

Mean

Hospital

of

Specia

l S

urg

ery

Score

pre-op post op

Hospital of Special Surgery score: A score for measuring post-arthroplasty function on a scale from 0 (worst) to 100 (best)

Consists of measurements for pain (max. 30), function (max. 22), ROM (max. 18), muscle strength (max. 10), deformity in flexion (max. 10) and instability (max. 10)

The mean scores

given are not

weighted to

account for follow-

up times.

Benchmark*

*A score equal or above the benchmark (85-100) is considered an indication of excellent outcome(Suk M, Hanson B, Norvell D, Helfet D. AO Handbook: Musculoskeletal Outcome Measures and Instruments. Thieme. 2005).

No. studies reporting = 9

MG results have been

excellent

• Argenson et al: 2002 JBJS 95%

survivorship 3-10 yr-no loosening

• Berger et al: 2005 JBJS,

98%survivorship at 10yrs-no loosening

• Pennington et al: 2006

J Arthroplasty 92% 11 years

38


Key published paper ZUK

Panni et al, 201180 knees; followed for a mean 4.5 years

• Statistically significant improvement in Knee Society

Scores

• Statistically significant increase in average flexion:

110º (pre-op) 127º (post-op)

• No cases of polyethylene wear, osteolysis, component

subsidence, or loosening

Conclusion:

• UKR provides early excellent results: 100%

survivorship rate of the ZUK prosthesis at 6 years.

• High success rates for UKR have been obtained only in

recent years, mainly due to improvement in prosthetic

design and materials, refinement of instruments and

surgical technique, and the strict selection of patients.

Reference: Panni AS, Vasso M, Cerciello S, Felici A.

Unicompartmental knee replacement provides early

clinical and functional improvement stabilizing over

time. Knee Surgery, Sports Traumatology, Arthroscopy.

2012;20(3):579-585.

4654

8294

Mean Knee Society

Scores (clinical)

Mean Knee Society

Scores (functional)

Pre-op

Post-op

Biswas et al, 201385 knees, followed for a maximum of 12

years.

• Mixture of M/G (<10%) and ZUK (>90%) prostheses in study

• No radiographic evidence of loosening, osteolysis, or

premature polyethylene wear.

• Estimated survivorship: 96.5% at 10 years.

Conclusion:

• UKA offered excellent early outcomes in this cohort of

younger, active patients.

• Authors hypothesized that these outcomes are related to

improved implant design and surgical technique.

Reference: Biswas D, Van Thiel GS, Wetters NG, Pack BJ,

Berger RA, Della Valle CJ. Medial unicompartmental knee

arthroplasty in patients less than 55 years old: minimum of

two years of follow-up. The Journal of arthroplasty. Jan

2014;29(1):101-105.

11/5/2015

14


Key published paper MG

Berger et al, 200562 knees, followed for a mean 12 years

•Improvement in mean Hospital for Special Surgery

knee score (mean pre-op: 55; post-op: 92)

•80% knees achieved an excellent result

•No radiographic evidence of loosening; no evidence

of periprosthetic osteolysis at final follow up

•Kaplan-Meier analysis revealed

•96% survival rate at 13 years (Endpoint: revision or

radiographic loosening)

•100% at 13 years (Endpoint: Aseptic loosening)

Conclusion:

This UKA design was associated with excellent clinical

and radiographic results after a minimum duration of

follow-up of 10 yearsReference: Berger RA, Meneghini RM, Jacobs JJ, et al. Results of

unicompartmental knee arthroplasty at a minimum of ten years of

follow-up. The Journal of bone and joint surgery. American

volume. May 2005;87(5):999-1006.

John et al, 201194 UKAs performed by a single surgeon,

followed for a mean 10.8 years (2–16 years)

•Mean ROM (post-operative): 110.6° (80–130°)

•89% of the knees had appropriate alignment

•Survival rate for medial UKA: 94% (10 years); 87% (15

years)

•Survival rate for the lateral UKA: 97% (5 years); 41% (8

years).

•Lateral UKA formed only 9.6% of all the replacements

Conclusion:

•The results for medial UKA are similar to reports by

other authors for similar and mobile bearing designs.

•UKA knee replacement results in a more kinematic

knee and produces good functional results.

Reference: John J, Mauffrey C, May P. Unicompartmental

knee replacements with Miller-Galante prosthesis: two to 16-

year follow-up of a single surgeon series. International

orthopaedics. Apr 2011;35(4):507-513.

The New Arthritic Patient

• Younger

• More active

• Greater expectations

• Increasing life expectancy

• Loads of them!!

41

UKA = Patient Satisfaction

• More “normal” knee

• Preserve ACL/PCL

• Preserves bone stock

• Faster recovery

• Appealing for young pts

• Less surgery for elderly

• Outpatient compatible

Among my happiest patients!

42

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Kaiser Permanente AAOS Poster exhibit

1784 unicompartmental knees

471 ZUK 5 revisions

The Choice of any implant other than

the ZUK UKA was associated with a

greater risk of revision

43Bini MD et al 2013

Thank You

44

Case

• 48 yo female

• BMI 36.5

• right knee pain with walking, standing, climbing stairs

• injections and NSAIDs help

• medial pain

• no instability

• works as home health PT

45

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Physical Exam

• BMI 36.5

• points to medial knee

• ROM 0-115

• stable V/V, ant/post drawer

• no pain with patellofemoral grind

• 7° varus deformity, passively correctable

46

47

48

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49

Who gets offered a UKA?

50

51

Medial Compartment Bone on Bone

No significant PF involvement

UKA offers the benefit

of a more highly functional knee.

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Anderson Orthopaedic Clinic

and

Anderson Orthopedic Research Institute

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Richard V. Williamson, MD

Skagit Regional Clinics

Mount Vernon, WA

UKA: From Outcast to Outpatient

Pertinent Disclosures

• Consultant:

Smith & Nephew, Zimmer Biomet

• ZUK developer

UKA: From Outcast to Outpatient

I. Spacer Block Technique for the ZUK

II. UKA as an Outpatient Procedure

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Spacer Block

Four surgical approaches:• Intramedullary (IM)

• Extramedullary (EM)

• Patient Specific Instrumentation (PSI)

• Spacer Block

EMIM PSI

Surgical Approach Options

Spacer Block TechniqueFor The ZUK

Acknowledgement: James Wood, MD

Principles of the Spacer Block Technique

I. Conservative and precise bone resection

II. Soft tissue envelope preservation to guide alignment

III. Components linked in flexion and extension

IV. Slight under correction and appropriate soft tissue tension as final goal

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Surgical Approach

•Parapatellar incision withleg in flexion

• Incise directly into joint capsule and resect anterior horn medial meniscus

Surgical Approach

Minimal Release of the MCL

Osteophyte Removal

Spacer Block Technique:Application of Tibial Assembly

• Guide adjusted for neutral tibial cut

• Slope at 5 degrees when parallel

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Resect Proximal Tibia

1) Determine Depth of Cut

(2-4mm)

3) Make the Cuts2) Verify Resection

Level

*Resect just enough tibial bone to avoid over correction

Remove and Review Tibial Cut

Depth: 2-4mmSlope: 5 degrees

Guide left in place

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Is the resection adequate to allow for slight under correction?

Is the soft tissue tension appropriate?

8mm

10mm

12mm

Insert Spacer Block

Resect the Distal Femur(Femoral Cut Guide is Linked to the Tibial Cut)

Linking in Extension 6 mm of Femoral Resection6 mm of Femoral Resection

Guide pinned

Cut made

Femoral Finishing GuideSizing and Alignment

6 Sizes

2-3mm

../../AppData/Local/AppData/Local/Local Settings/Temporary Internet Files/OLK83/2009 UKA Dr Wood.ppt#37. 5%D06 mm of Femoral Resection

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Femoral Finishing Guide:Fixation and Alignment


*Add screw


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Finish the Femur

Size the Tibial Component6 Sizes

Finish the Tibia

Fix with screw or pin and drill post holes

Impact Tibial Fixation Provisional

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Perform Trial Reduction

Apply Femoral Provisional

Insert Tibial Provisional Articular Surface (9mm)

Trial ReductionCheck Soft Tissue Tension

Trial ReductionCheck Alignment

Make decision on poly thickness 1mm change in poly thickness = 1.2°

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Your Standard Cement Technique

“A Little Dab Will Do You”

Implant the Final Component

*Remove Excess Cement

Tibial component Femoral component

Balanced Knee

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DONE!A Simple and Reproducible Technique

UKA as an Outpatient Procedure:

A Process in Evolution



Mount Vernon, WA

Early UKA Experience: 1989-1999

SMALL implants…through a HUGE incision

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Evolution of Outpatient UKA TechniqueHospital based

• 1999 designed EM instrumentation for

MG UKA

• Much less invasive

• 1999-2004 outpatient UKA

in the hospital

Discharge decision made

post-op (10-15%)

Outpatient UKA: Free Standing ASC

August 2004 through June 2013

547 UKA’s, all ZUK’s utilizing EM Instrumentation

2004-2008 • 15%-20% of UKA

volume

• No outpatient code

2009-2013• 50-70% of UKA

volume

• CPT code 27446

Why Outpatient UKA?

• Volumes & Efficiency: Overwhelming Hospitals

• Economic Considerations: Less expensive (saves health care $)

• Surgeon control over the surgical process

• Lifestyle improvement

• Opportunity for ancillary income

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Patient Selection for Outpatient UKA

•ASA 1-3 (American Society of Anesthesiologists)

•No unstable major medical conditions

•Motivated towards outpatient concept

•Home support

•Exclusions: Morbid Obesity, Sleep Apnea

• Initial protocol (first 5 yrs): multimodal anesthesia program with pre-op medications (celecoxib, gabapentin, oxycontin)

•Current program (last 6 yrs): no pre-admission medication

•Prophylactic antibiotics, ketorolac on admission

Pre-op medication for Outpatient UKA

Anesthesia for Outpatient UKA

•LMA (Laryngeal mask) utilized in over 90% Induction: Lidocaine 10mg/kg, propofol 10mg/kgAfter LMA with spontaneous ventilation: desflurane at

1 MAC, ketamine 2mg/kg, labetalol 1mg/kg, dexamethasone 8mg (Nausea prevention)

Intra operative narcotics are avoided

•Spinal or GA with intubation occasionally employed

•All patients were supplemented with: Incisional injectionPericapsular injection Intra-articular injection

No regional blocks were utilized

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Local Supplementation of Skin and Fascia

• Skin injected pre-op

(Bupivacaine 0.25% with epi)

• Fascia Intra-op


Anesthesia Pericapsular Injection

Pericapsular Injection-Prior to implantation

-22 gauge spinal


Anesthesia Intra-articular Injection

Intra-articular Injection

-Performed after closure

-Ropivacaine, Ketorolac, andMorphine

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• PO narcotic

•Fentanyl IV for breakthrough

•Antimimetics PRN

PACU (Recovery) for Outpatient UKA

Outpatient UKA:Discharge

• PO narcotic; usually oxycodone or hydromorphone

• NSAID’s on an individual basis

• ASA for DVT prophylaxis

• Assistive Device (Walker/Crutches)

Outpatient UKA: Post-op care

• Phone call POD 1

• Dressing change at 4-7 days: patient, family, or in office

• Start formal PT at 1-2 weeks

• Surgeon visit at 2 weeks and 6 weeks

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August 2004-June 2013: 547 outpatient UKA’s

• No peri-operative hospitalizations

• One infection, hospitalized at 4 weeks

• 2 DVT’s, treated as outpatients

• One fall with wound dehiscence at POD 10, treated as outpatient

Outpatient UKA:Results

Outpatient UKA: Economic FeasibilityAcknowledgment- J. Mandume Kerina, MD

$17,495

$12,322

$8,006 $8,596 $9,294 $9,601 $9,732

$11,372

$10,921

$6,627 $7,068 $7,756 $7,888 $7,987

$4,000

$8,000

$12,000

$16,000

$20,000

2008 2009 2010 2011 2012 2013 2014

OP Hosp ASC

Outpatient UKA: Cost Analysis (Kerina)

Pre Op

RN 30/Hr $30.00

Pre Op Medication $25.00

OR

Cir RN 30/Hr $30.00

Tech 20/Hr $40.00

OR Supplies $4,433.95

Post Op

RN 30/Hr $30.00

RN 30/Hr $30.00

Post Op Medication $335.29

Total Cost $4,953.95

Medicare Pays $7,987.49

Profit Margin $3,033.54

Contribution Margin 38%

Contribution Margin 38%

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• Outpatient UKA is a safe, simple and economically attractive procedure

• We currently treat these patients as any other outpatient procedure

• Major source of revenue for an outpatient surgery center

Outpatient UKA:Summary

Thank you for your attention



Mount Vernon, WA

Documents

Disclosure - Amazon Web Services · PDF file · 2015-11-09Disclosure •Consultant - Smith and Nephew, ... ASA Physical Status Classification System ASA Relative Value Guide®