UKR, Unicompartmental total knee replacement, Newer therapy, Arthroplasty

1. #ash72
UNICOMPARTMENT KNEE ARTHROPLASTY
MODERATOR : PROF. M. MOHAN KUMAR
PRESENTOR : Dr. Ashik

2. #ash72

3. #ash72
UKR , since 1970 – only if one compartment of knee is affected
MEDIAL more than 90%
LATERAL less than 10%

4. #ash72
PATIENT SELECTION :
1. Painful OA or Osteonecrosis ( single compartment )
2. Age less than 60 years
3. BMI less than 30
4. Low demand activities
5. ROM more than 100’
6. Flexion contractures less than 5’
7. Varus / Valgus less than 15’
8. Intact Anterior cruciate ligament
9. No signs of inflamatory arthritis

5. #ash72
CONTRA INDICATIONS :
1. Inflamatory forms of arthritis
2. Absent or severely damaged ACL / PCL / MCL
3. Intra articular varus / valgus
4. FFD more than 15’
5. Flexion less than 100’
6. Associated cartilage pathology
7. Bone loss with eburnation and grooving in the lateral part of
patellofemoral joint .

6. #ash72
INFLAMATORY
ARTHRITIS
DISEASE OF
SYNOVIUM
CANT BE
LIMITED TO ONE
COMPARTMENT
VARUS / VALGUS
DEVOLEPMENT
OF ARTHRITIS IN
ALL
COMPARTMENTS
NEEDS TOTAL
KNEE
REPLACEMENT
FFD MORE THAN
15’
NEED OF SOFT
TISSUE/
LIGAMENT
MANIPULATION
NEEDS TOTAL
KNEE
REPLACEMENT
RUPTURED
LIGAMENTS
ACL / MCL/PCL
INTACT
LIGAMENTS
ARE NEEDED
UKR DOESN’T
COMPROMISE
LIGAMENTS

7. #ash72
SURGICAL TECHNIQUES :
SKIN INCISION

8. #ash72

9. #ash72

10. #ash72

11. #ash72

12. #ash72

13. #ash72

14. #ash72
CONCERNS ????
1. Principles of ligament balancing in TKA cannot be
applied to UKA . Because the collateral ligaments
should not released in UKA . ( considered to have a
more native knee )

15. #ash72
Remove the osteophytes on the medial or lateral of femoral
condyle/ intercondylar notch
To avoid late impingement with the ACL on the notch
As it may lead to guillotine effect on the ACL
MARIE ANTOINETTE EFFECT

16. #ash72
In Lateral UKR , during screw home mechanism
Even a good femoral implant position during flexion , may
undergo internal rotation in extension
Impingement of the implant on the tibial spine eminence
When positioning the femoral component, it is frequently
necessary to mark the correct alignment in extension rather
than in flexion to avoid this impingement

17. #ash72

18. #ash72
Overcorrection of the deformity
Leads to progression of osteoarthritis of the unreplaced
compartment after UKA
Pre/ intra operative planning & proper use of instrumentation set.
To correct
this

19. #ash72

20. #ash72

21. #ash72
TYPES OF IMPLANTS

22. #ash72
FIXED BEARING PROSTHESIS

23. #ash72

24. #ash72
MOBILE BEARING PROSTHESIS

25. #ash72

26. #ash72
ADVANTAGES OF FIXED OVER MOBILE :
Those advantages include a lower risk of early failure and the
ability to extend the indications for surgery to include anterior
cruciate ligament (ACL)-deficient knees in some cases .
ADVANTAGES OF MOBILE OVER FIXED :
It optimizes the congruency of the femoral and tibial components
throughout normal range of motion, more closely replicates the
anatomic meniscus by enabling angular and translation motion,
and minimizes tibial contact forces and stress transfer through
two joint interface

27. #ash72

28. #ash72
COMPLICATIONS OF UKA
PROGRESSION OF ARTHRITIS :
- time dependent gradual , but inevitable , spread of OA to the other
compartments
- 5 % of cases , at a mean of 7.0 years devolep OA
- In most cases TKA Is indicated , however fewer surgeons opt to do
UKA in the affected compartment if the other prosthesis is
satisfactory

29. #ash72
INFECTION :
MANAGEMENT :
1. Early open debridement & change of meniscal bearing ( adviced
: antibiotic loaded ) + i.v antibiotics
2. TKA , and may require a stemmed tibial implant

30. #ash72
TIBIAL PLATEAU FRACTURE :
- 0.3% Of cases acquire periprosthetic fracture
- If minimal displacement : external splinting
- If significant displacement : ORIF with butress plating
- If fracture has united , and still pain persists chronically : revise to
TKA

31. #ash72
DISLOCATION OF MOBILE BEARING
- 0.73% cases from 2 to 12 years
- Mobile more than fixed
- Caused due to distraction of the joint
And displacement of the bearing
- Manipulation under anesthesia , but leads to relocation
- In case of traumatic dislocation , managed by open insertion of a
new bearing

32. #ash72
BONE OVERLOAD :
Finite element analysis shows the
tibial strain increases following
UKA below the tibial components
- There occurs anteromedial pain
postoperatively , it settles as
remodelling occurs and the
strain returns to normal .
- Probably due to the irritation of
medial soft tissues
- Manage conservatively with analgesics .
- May take 3 to 6 months to settle
- If symptoms don’t improve after 2 years , plan for revision.

33. #ash72
REHABILITATION :
1. Patients recuperate from UKA more rapidly than TKA . Vigorous
excercises may lead to more swelling and painful knee
2. Most patients can be made to walk within 4 to 6 hours post
procedure , if quadriceps function is satisfactory
3. 80% of the patients are discharged within 24hrs of procedure ,
with oral analgesics for a week

34. #ash72

35. #ash72
ADVANTAGES OVER TKR :
1. Can be advocated in young adults
2. Less surgical time
3. Less blood loss
4. Preservation of bone stock in the remaining compartment
5. Preservation of ligaments / cruciate mechanism
6. Minimal trauma to extensor mechanism ( allowing it to faster
rehabilitation )
7. Easy revision to UKA or conversion to TKA

36. #ash72
COMPARISON WITH TKR :
- Revision rate of UKA is approximately 3 times that of TKA
- UKA has better oxford knee society score than TKA

37. #ash72

38. #ash72

39. #ash72

40. #ash72