varus knee

Question 1

what are the surgical options for medial compartment OA in older patients?

Answer 1

UKR

Advantages
* bone and ligament preserving
* high patient satisfaction
* good rom
* cheaper
* quicker recovery
* reduced medical risks

Disadvantages
* revision to TKR not as good as primary TKR
* poor survivorship compared to TKR
* may require later revision to TKR

TKR
Advantages
* good survivorship - less revision at 10yrs on NJR
* deals with PFJ uncertainty
* good (not excellent) patient sat scores

Disadvantages
* next revision more complex
* 20% patients not satisfied
* bone loss

Lancet paper 2019
comparing TKR and UKR
- UKR - 70% survivorship at 25yrs
- TKR - 82% survivorship at 25yrs

Question 2

what are the surgical options for medial comp OA in younger patients

Answer 2

HTO vs UKR vs TKR

• 50yrs - go for arthroplasty
• female - do better with arthroplasty
• male manual workers -30/40s - better with HTO

Question 3

what are the contraindications to a UKR?

Answer 3

• inflammatory OA
• ACL deficiency
• fixed varus >10 deg
• fixed valgus >5 deg
• FFD: 5-10 deg
• tricompartmental OA
• anterior knee pain suggestive of PFJ OA

Question 4

what type of UKR do you use?

Answer 4

Oxford UKR
fixed bearing implant (better survivorship than mobile)
94% survivorship at 10yrs
13A rating

Question 5

what do you do if you cut the MCL during a TKR?

Answer 5

• increased level of constraint by performing a hinged knee replacement

Question 6

assessment of patient with medial OA

Answer 6

• varus correctability
• LCL laxity
• acl integrity
• BMI
• Smoking hx
• previous treatment

Question 7

High tibial osteotomy - contraindications?

Answer 7

• inflammatory arthritis
• osteoporosis
• end stage OA
• obesity
• > 20 degree correction
• near total lateral menisectomy
• extra-articular deformity
• incompent collaterals
• patellofemoral OA
• flexion contracture
• <90 deg flexion

Question 8

High tibial osteotomy
- what kind of osteotomy would you perform? - uni or biplanar - opening or closing
- femoral or tibia or both?
- how to prevent hinge fracture?

Answer 8

Femoral and tibial cut
- if large correction required
- avoid joint line obliquity

Biplanar cut
- more stable than a uniplanar cut as two surfaces and patella tendon attached distally
- risk of patella baja

how to prevent hinge fracture?
- hinge wire
- II
- avoid the last 5-10mm

Question 9

how do you work out angles for tibia/ fibular osteotomies?

Answer 9

1. decide where deformity is and if you need two osteotomies or one
2. deformity can be characterised by either the anatomical or mechanical access
3. minachi method