Unicompartmental Arthroplasty

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Unicompartmental Arthroplasty

• John Goodfellow
• Nuffield Orthopaedic
• Centre, Oxford

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AnteromedialOsteoarthritis(30 of OA knees)
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Fixed Bearing UKR

• Wear inescapable Incongruous
• Thin polyethylene
• Catastrophic failure

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Meniscal function
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Phase 1 1976
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Polyethylene Wear

• Average penetration rate 0.03mm per year
• Average time for 1mm penetration 33 years

10 year retrieval
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Indications

• Not Contraindications
• Patello-femoral joint
• Chondrocalcinosis
• Obesity
• Age
• Activity

• Criteria
• Antero-medial OA
• Intact ACL
• Full thickness lateral
• Correctable varus
• FFD less than 15
• 1 in 3 OA knees

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UKR - Designers series

• 10 year survival 98
• Murray et al JBJS 1998

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Svard Price (AAOS 2006)
20 yr survival 92 CI 15.1 10 yr 90 Good or
Excellent HSS (n187)
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Minimally Invasive Surgery
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MIS results Early Recovery

• Less Bleeding
• Lower Morbidity
• Shorter Hospital Stay
• Quicker Flexion
• Time to recovery
• 3x faster than TKR (plt0.001)
• 2x faster than open UKR (plt0.001)

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National Registers

• Measured by revision, failure rate of UKR at
  10yrs is approx x 2 TKR
• National failure rates of UKR are higher than
  reports from Specialist Centres
• Failure rates of UKR vary with the experience of
  the surgeon

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Dependence on Surgical Experience(Roberttson et
al)
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Instructional Courses

• To diminish the learning curve
• To teach indications
• To improve surgical technique