Present Status of Unicondylar Knee Arthroplasty

Dr. Anthony S. Unger
Washington, DC

1. PRESENT STATUS OF PRESENT STATUS OF
UNICONDYLAR KNEE UNICONDYLAR KNEE
ARTHROPLASTYARTHROPLASTY
20072007
ANTHONY S UNGER, MDANTHONY S UNGER, MD
DIRECTOR; GW UNIVERSITY MIS DIRECTOR; GW UNIVERSITY MIS
HIP/KNEE SURGERY CENTERHIP/KNEE SURGERY CENTER
WASHINGTON CENTER FOR HIP AND WASHINGTON CENTER FOR HIP AND
KNEE SURGERYKNEE SURGERY

2. THE REBIRTH OF THE THE REBIRTH OF THE
UNICOMPARTMENT UNICOMPARTMENT
REPLACEMENT REPLACEMENT

4. UNI HISTORY/OLDUNI HISTORY/OLD
•MCKEEVERMCKEEVER
•MACINTOSHMACINTOSH
•GUNSTONGUNSTON
•MARMORMARMOR

5. UNI FAILURE UNI FAILURE
•POOR SELECTIONPOOR SELECTION
•POOR TECHNIQUEPOOR TECHNIQUE
•POOR IMPLANTPOOR IMPLANT

6. UNI HISTORY/NEWUNI HISTORY/NEW
•CHRISTIANSEN, 9 YR FU 3.6% CHRISTIANSEN, 9 YR FU 3.6%
REVISIONREVISION
•SCOTT, 4 YR FU, 3% REVISIONSCOTT, 4 YR FU, 3% REVISION
•REPICCI, 8 YR FU, 8% REVISIONREPICCI, 8 YR FU, 8% REVISION
•BERGER, 1O YR SURVIVAL=98%BERGER, 1O YR SURVIVAL=98%
•ARGENSON,10 YR SURVIVAL=94%ARGENSON,10 YR SURVIVAL=94%
•PENNIGTON,<60,10 YR SURVIVAL=92%PENNIGTON,<60,10 YR SURVIVAL=92%

7. HOW DURABLE ARE UNIs??HOW DURABLE ARE UNIs??
•JBJS 2007, FURNES ET AL., NORWEGIAN JBJS 2007, FURNES ET AL., NORWEGIAN
REGISTRYREGISTRY
•2288 UNI VS 3032 TKA2288 UNI VS 3032 TKA
•10 YR SURVIVAL 80% FOR UNI VS 92% FOR 10 YR SURVIVAL 80% FOR UNI VS 92% FOR
TKATKA
•MECHANICAL LOOSENING MOST COMMON MECHANICAL LOOSENING MOST COMMON
FAILURE MODEFAILURE MODE
•40% REDUCTION OF RISK OF REVISION AT 40% REDUCTION OF RISK OF REVISION AT
HOSPITALS WERE 25 UNIs DONE PER YRHOSPITALS WERE 25 UNIs DONE PER YR

8. UNI INDICATIONSUNI INDICATIONS
•SINGLE COMPARTMENT DISEASE(95% SINGLE COMPARTMENT DISEASE(95%
MEDIAL)MEDIAL)
•BY XRAY AND HISTORYBY XRAY AND HISTORY
•<10 VARUS, VALGUS OR FC<10 VARUS, VALGUS OR FC
•ACL DEF IS OKACL DEF IS OK
•ANY AGEANY AGE
•WT <250WT <250

9. HISTORY—THE MAGIC HISTORY—THE MAGIC
WORDSWORDS
•““I HAVE PAIN ON THE INSIDE OF MY I HAVE PAIN ON THE INSIDE OF MY
KNEE”KNEE”
•““STAIRS AND SQUATTING DO NOT STAIRS AND SQUATTING DO NOT
MAKE MY KNEE WORSE”MAKE MY KNEE WORSE”

10. PREOP STUDIESPREOP STUDIES
•WT BEARING AP/30 DEGREE PAWT BEARING AP/30 DEGREE PA
•SCOPE HELPFUL BUT NOT SCOPE HELPFUL BUT NOT
NECESSARYNECESSARY
•CT/MRI/BONE SCAN NOT NECESSARYCT/MRI/BONE SCAN NOT NECESSARY
•MERCHANT VIEWMERCHANT VIEW
•LATERAL VIEWLATERAL VIEW

11. IMPLANT SELECTIONIMPLANT SELECTION
•FIXED BEARING RATHER THAN FIXED BEARING RATHER THAN
MOBILEMOBILE
•ROUND ON FLAT MORE FORGIVINGROUND ON FLAT MORE FORGIVING
•PROVEN TRACK RECORDPROVEN TRACK RECORD
•GOOD INSTRUEMENTSGOOD INSTRUEMENTS

12. IMPLANT SELECTIONIMPLANT SELECTION

13. POLY WEARPOLY WEAR
•GREENWALD, WEAR EQUAL TO FIXED GREENWALD, WEAR EQUAL TO FIXED
BEARING TKABEARING TKA
•POLY FAILURE USUALLY DO TO POLY FAILURE USUALLY DO TO
MALALIGNMENTMALALIGNMENT
•MODULAR TRAY OKMODULAR TRAY OK

14. REVISION OF THE UNIREVISION OF THE UNI
•EASIER THAN REVISING HTOEASIER THAN REVISING HTO
•MAY NEED WEDGES OR MAY NEED WEDGES OR
BLOCKSBLOCKS
•REVISE TO TKA NOT ANOTHER REVISE TO TKA NOT ANOTHER
UNIUNI

15. REPICCIREPICCI
•““FIRST IMPLANT, WILL FIRST IMPLANT, WILL
NEED ANOTHER NEED ANOTHER
SURGERY”SURGERY”

16. BERGERBERGER
•““LAST AS LONG AS TKA, LAST AS LONG AS TKA,
LIKE THEM IN >80 AND LIKE THEM IN >80 AND
<60”<60”
•““MY INDICATIONS ARE MY INDICATIONS ARE
EXPANDING”EXPANDING”

17. SCOTTSCOTT
•““ALTERNATIVE TO HTO IN ALTERNATIVE TO HTO IN
FEMALES, GOOD CHOICE FEMALES, GOOD CHOICE
IN OCTOGENARIANS”IN OCTOGENARIANS”

18. RANAWATRANAWAT
•““I DO TKA, SEE LITTLE I DO TKA, SEE LITTLE
NEED FOR THIS”NEED FOR THIS”

19. BOOTHBOOTH
•““I DO TKA IN 15 MINUTES, 10 I DO TKA IN 15 MINUTES, 10
PER DAY WHAT DO I NEED PER DAY WHAT DO I NEED
THIS HEADACHE FOR”THIS HEADACHE FOR”

20. UNGERUNGER
•IDEAL CANDIDATE 50-65 IDEAL CANDIDATE 50-65
OR OCTAGENERIANOR OCTAGENERIAN
•““ONLY I/20 PATIENTS A ONLY I/20 PATIENTS A
GOOD CANDIDATE”GOOD CANDIDATE”

21. SURGICAL TECHNIQUESURGICAL TECHNIQUE
•MIS, NO PATELLA EVERSIONMIS, NO PATELLA EVERSION
•23 HR STAY23 HR STAY
•NO CORRECTION, UNI IS A NO CORRECTION, UNI IS A
RESURFACING, NOT A PARTIAL TKARESURFACING, NOT A PARTIAL TKA
•CUT TIBIA FIRSTCUT TIBIA FIRST
•START WITH BIG INCISION, WORK START WITH BIG INCISION, WORK
TOWARDS 4 INCH INCISIONTOWARDS 4 INCH INCISION

22. SURGICAL TECHNIQUESURGICAL TECHNIQUE
•CUT TIBIAL SLOPE ANATOMICCUT TIBIAL SLOPE ANATOMIC
•IF TIGHT IN FLEXION INCREASE IF TIGHT IN FLEXION INCREASE
SLOPE TIBIA CUTSLOPE TIBIA CUT
•IF TIGHT IN EXTENSION,CUT 2MM IF TIGHT IN EXTENSION,CUT 2MM
MORE FEMUR AND/OR DECREASE MORE FEMUR AND/OR DECREASE
SLOPE TIBIA CUTSLOPE TIBIA CUT
•2MM LAXITY IN FLEX/EXT GAP2MM LAXITY IN FLEX/EXT GAP
•WATCH OUT FOR PATELLA WATCH OUT FOR PATELLA
IMPINGEMENTIMPINGEMENT

24. SURGICAL TECHNIQUESURGICAL TECHNIQUE

26. SURGICAL TECHNIQUESURGICAL TECHNIQUE

28. SURGICAL TECHNIQUESURGICAL TECHNIQUE

29. SURGICAL TECHNIQUESURGICAL TECHNIQUE

31. SURGICAL TECHNIQUESURGICAL TECHNIQUE

32. SURGICAL TECHNIQUESURGICAL TECHNIQUE

33. SURGICAL TECHNIQUESURGICAL TECHNIQUE

34. SURGICAL TECHNIQUESURGICAL TECHNIQUE

39. SURGICAL TECHNIQUESURGICAL TECHNIQUE

44. GOOD UNIGOOD UNI

45. GOOD UNIGOOD UNI

46. GOOD UNIGOOD UNI

47. GOOD UNIGOOD UNI

48. BAD UNIBAD UNI

49. BAD UNIBAD UNI

50. FIX BAD UNIFIX BAD UNI

51. REVISE UNIREVISE UNI

52. ““UNICOMPARTMENT KNEE UNICOMPARTMENT KNEE
REPLACEMENT IS HERE TO REPLACEMENT IS HERE TO
STAY”STAY”

53. THANK YOUTHANK YOU