10-year Outcomes of High Tibial Osteotomy for Medial Compartment

Osteoarthritis of the Knee

Justin RoeNick Howells, Lucy Salmon, Alison Waller, Leo Pinczewski

North Sydney Orthopaedic and Sports Medicine CentreAustralia

Disclosures

I declare that in the past three years I have:

• held shares in: Optimized Ortho

• received royalties from: n/a

• done consulting work for: Stryker

• given paid presentations for: Smith and Nephew

• received institutional support from: Stryker

Optimized Ortho

Signed: Justin Roe

Associate Professor Justin Roe

Aim

• Prospectively assess the long term clinical outcome of HTO

• Identify preoperative factors associated with HTO survivorship

Associate Professor Justin Roe

Patient Selection • Symptomatic medial compartment

osteoarthritis with• Clinical and/or radiologic bone on

bone articulation in the medial compartment

Kellgren Lawrence grades 3 and 4• Inclusion Criteria

• Modified Coventry lateral closing wedge osteotomy 2000-2002

• Consent to prospective research over 10 yrs

• Not receiving compensation

Method

Enrollment

Follow-Up + Analysis

n=100

Excluded (n=64)Did not consent to prospective research over 10 yearsWorkers Comp

n = 1642000-2002

HTO

• Lost to follow-up n = 3 • Deceased n = 2 • Analysed n = 95• Further Surgery n = 21• Reviewed n = 74

Associate Professor Justin Roe

Assessment

Preoperatively and at 5 and 10 years• WOMAC• KOOS • Clinical Knee Society Score• Long leg weight bearing alignment

radiographs

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Study Group n = 100

• Mean age 50 years (26-66)• 69 males (73%), 26 Females (27%)• Mean BMI 28 (21-39)• Mean Preop MechAxis 6.00 varus

41

32

16

2 2 3

Diagnosis

Idiopathic

Post medial meniscectomy

Hx of ACL injury

Hx of PCL injury

AVN

Fracture

Operative Technique: Modified Coventry Closing Wedge HTO, Staple fixation, HKB 6 weeks

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Overall Results (n = 97)

At 10 years 21 proceeded to further surgery• UKA n = 5 • TKA n = 15• Revision HTO n = 1

• Mean time to further surgery• 60 months (15-124 months)

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Results

Further surgery No surgery P• No of patients 21 74• Preop WOMAC 47 65

0.001• Preop KSS 101 130

0.001• Mean Age 54 49

0.005• Mean BMI 30.2 27.9

0.010

• No significant difference in preop alignment (p=0.69), preop diagnosis (p=0.42), MCL status (p=0.69), wedge size (p=0.10), gender (p=0.07)

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HTO Overall Survivorship87% 79%

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Survivorship Stepwise Multiple Regression

Variable        Hazard Ratio 95% CI    p

Preop WOMAC < 45   10.7  4 - 29 .001

Age > 55 years                 6.5              2 - 18   .001

BMI > 30                  3.0 1.2 - 8 .017     

Relative contribution of each variable on increasing the Odds of Failure over 10 years

Significant Results

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BMI effect on Survivorship

82%

79%

71%

90% 84%

BMI < 30

BMI > 30

Significant Results

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Age effect on Survivorship

69% 79%63%

97% 87%

AGE < 55 yr

AGE > 55 yr

Significant Results

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Australian Joint Registry 2012

Age < 55 5 yr 10 yr

HTO 97% 87%

UKA 87% 77%

TKA 92% 88%

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Pre op WOMAC score effect on Survivorship

63%

79%

42%

93% 88%

WOMAC > 45

WOMAC <45

Significant Results

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IDEAL

BMI >30, >55yrs, WOMAC <45

Survivorship ‘IDEAL’ candidate (n=34)

Age < 55 BMI < 30 WOMAC > 45

80%

69%

100% 97%

p = 0.01

Significant Results

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10 year Clinical Outcomes

preop 5 years 10 years0

102030405060708090

100

61

88 84

Mean WOMAC

WOMAC

Survivor Results (n=74)

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Significant Results WOMAC and Age

WOMAC Age < 55 years >55 years P• Preop 63 58 0.24• 5 year 86 93* 0.004• 10 year 82 89* 0.04

Older patients had significantly better WOMAC scores at 5 and 10 years

Survivor Results (n=74)

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DiscussionPreviously unreported in the osteotomy literature• Pre-op WOMAC score as a predictor of long term

outcome for osteotomy• Older patients age > 55 years have significantly

higher 10 year WOMAC score outcomes than their younger counterparts, although lower survivorship

• 10 year prospective analysis HTO for Kellgren Lawrence grade 3 and 4 medial OA

Associate Professor Justin Roe

Conclusion

• Closing Wedge High Tibial Osteotomy is confirmed in the literature as a safe and reliable option for medial compartment osteoarthritis of the knee

• HTO is the procedure of choice in patients Age < 55 years BMI < 30 preop WOMAC > 45

Associate Professor Justin Roe

Thank you for your attention.

Associate Professor Justin Roe

APKASS Japan 2014Associate Professor Leo Pinczewski

APKASS Japan 2014Associate Professor Leo Pinczewski