Present Status of Unicondylar Knee Arthroplasty

PRESENT STATUS OF PRESENT STATUS OF UNICONDYLAR KNEE UNICONDYLAR KNEE

ARTHROPLASTYARTHROPLASTY20072007

ANTHONY S UNGER, MDANTHONY S UNGER, MDDIRECTOR; GW UNIVERSITY MIS DIRECTOR; GW UNIVERSITY MIS

HIP/KNEE SURGERY CENTERHIP/KNEE SURGERY CENTERWASHINGTON CENTER FOR HIP AND WASHINGTON CENTER FOR HIP AND

KNEE SURGERYKNEE SURGERY

THE REBIRTH OF THE THE REBIRTH OF THE UNICOMPARTMENT UNICOMPARTMENT REPLACEMENT REPLACEMENT

UNI HISTORY/OLDUNI HISTORY/OLD

• MCKEEVERMCKEEVER• MACINTOSHMACINTOSH• GUNSTONGUNSTON• MARMORMARMOR

UNI FAILURE UNI FAILURE

• POOR SELECTIONPOOR SELECTION• POOR TECHNIQUEPOOR TECHNIQUE• POOR IMPLANTPOOR IMPLANT

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%

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

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

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”

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

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

IMPLANT SELECTIONIMPLANT SELECTION

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

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

REPICCIREPICCI

• ““FIRST IMPLANT, WILL FIRST IMPLANT, WILL NEED ANOTHER NEED ANOTHER SURGERY”SURGERY”

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”

SCOTTSCOTT

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

RANAWATRANAWAT

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

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”

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”

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

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

SURGICAL TECHNIQUESURGICAL TECHNIQUE

SURGICAL TECHNIQUESURGICAL TECHNIQUE

SURGICAL TECHNIQUESURGICAL TECHNIQUE

SURGICAL TECHNIQUESURGICAL TECHNIQUE

SURGICAL TECHNIQUESURGICAL TECHNIQUE

SURGICAL TECHNIQUESURGICAL TECHNIQUE

SURGICAL TECHNIQUESURGICAL TECHNIQUE

SURGICAL TECHNIQUESURGICAL TECHNIQUE

SURGICAL TECHNIQUESURGICAL TECHNIQUE

GOOD UNIGOOD UNI

GOOD UNIGOOD UNI

GOOD UNIGOOD UNI

GOOD UNIGOOD UNI

BAD UNIBAD UNI

BAD UNIBAD UNI

FIX BAD UNIFIX BAD UNI

REVISE UNIREVISE UNI

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

THANK YOUTHANK YOU