UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

INDICATIONSINDICATIONS

N. CONFALONIERIN. CONFALONIERI

ORTHOPAEDIC ORTHOPAEDIC DEPARTMENTDEPARTMENT

ORTHOPAEDIC AND ORTHOPAEDIC AND TRAUMATOLOGIC CENTERTRAUMATOLOGIC CENTER

MILANMILAN

-Patients selection-Patients selection-Operative techniques-Operative techniques-Prosthetic design-Prosthetic design-Few complications-Few complications

INDICATIONS:INDICATIONS:

• Unicomp. arthrosisUnicomp. arthrosis• Intact controlateral compartmentIntact controlateral compartment

• (Ist and 2d Ahlback’s classes) (Ist and 2d Ahlback’s classes)

• Asimptomatic patellofemoral jointAsimptomatic patellofemoral joint

• ROM > 90°ROM > 90°

• Axial deformity < 15° Axial deformity < 15°

INDICATIONS:INDICATIONS:

• Flexion deformity < 5°Flexion deformity < 5°

• Age > 60 y.Age > 60 y.

• Body Weight: < 82 kgBody Weight: < 82 kg

• No joint laxity (intact ACL) No joint laxity (intact ACL)

• No pain at restNo pain at rest

• No systemic disordersNo systemic disorders

(reumathoid arthr., hemophilia)(reumathoid arthr., hemophilia)

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

AGE ?AGE ?

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

RELATIVE CONCEPT !RELATIVE CONCEPT !

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

PATELLOFEMORAL PATELLOFEMORAL JOINT ?JOINT ?

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

RARELY INTACT !RARELY INTACT !

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

JOINT STIFFNESS ?JOINT STIFFNESS ?

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

TO BE EVALUATED IN TO BE EVALUATED IN EACH CASEEACH CASE

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

JOINT LAXITY ?JOINT LAXITY ?

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

ACCORDING TO AGE ACCORDING TO AGE AND ACTIVITYAND ACTIVITY

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

BODY WEIGHTBODY WEIGHT ? ?

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

RELATIVE CONCEPT !RELATIVE CONCEPT !

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

CONTROINDICATIONS:CONTROINDICATIONS:

• Flexion deformity > 15°Flexion deformity > 15°

• Osteoporosis + Obesity + DeformityOsteoporosis + Obesity + Deformity

• Technical errors: - polyetylene < 6 mmTechnical errors: - polyetylene < 6 mm

• - ipercorrection- ipercorrection

• - hip disease- hip disease

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS

CONTROINDICATIONS:CONTROINDICATIONS:

• Reumathoid arthr., HemophiliaReumathoid arthr., Hemophilia

• Serious joint laxitySerious joint laxity

• Serious varus deformitySerious varus deformity

• Serious Serious symptomaticsymptomatic patello-femoral patello-femoral

arthritis arthritis

-Patients selection-Patients selection-Operative techniques-Operative techniques-Prosthetic design-Prosthetic design-Few complications-Few complications

-Patients selection-Patients selection-Operative techniques-Operative techniques-Prosthetic design-Prosthetic design-Few complications-Few complications

-Patients selection-Patients selection-Operative techniques-Operative techniques-Prosthetic design-Prosthetic design-Few complications-Few complications

COMPLICATIONSCOMPLICATIONS• DVT: DVT: 44 (1.8%) (1.8%)

• CONDILE FRACTURES: CONDILE FRACTURES: 1 tibial1 tibial (0.4%) (0.4%)

• 1 femoral1 femoral (0.4%) (0.4%)

• SUPERFICIAL INFECTIONS: SUPERFICIAL INFECTIONS: 6 6 (2.8%) (2.8%)

• SYNOVITIS: SYNOVITIS: 3 3 (1.1%) (1.1%)

UNICOMPARTMENTAL UNICOMPARTMENTAL KNEE PROSTHESISKNEE PROSTHESIS1988 - 2000: 1988 - 2000: 211 cases211 cases

Scala sensorizzataScala sensorizzata

staircase

handrailing

platform

instrumentedsteps

Instrumented Staircase

for Ground Reaction Measurement

Robert Riener1,2, Marco Rabuffetti1,

Carlo Frigo1, Jochen Quintern3, Günther Schmidt2

Descent Descent Uni fixed bearingUni fixed bearing (K,1148)(K,1148)

Normal dynamic and videomatic Normal dynamic and videomatic (cynematic)(cynematic)

0 20 40 60 80 100-5

-4

-3

-2

-1

0

1

% Stride duration Abs stride duration (Normal:1.21 s) (Subject:1.29 s)

Ab

s. W

/Kg

G

en.

Subject : K (#1148) Direction : DOWN KneePower

Normal FixedPlateauUntreated

0 20 40 60 80 100-1.6

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

% Stride duration Abs stride duration (Normal:1.21 s) (Subject:1.29 s)

Flx

. N

/Kg

E

xt.

Subject : K (#1148) Direction : DOWN KneeMoment

Normal FixedPlateauUntreated

0 20 40 60 80 10010

20

30

40

50

60

70

80

90

100

% Stride duration Abs stride duration (Normal:1.27 s) (Subject:1.29 s)

Ext

. d

eg

F

lx.

Subject : K (#1148) Direction : DOWN KneeAngle

Normal FixedPlateauUntreated

Potenza

Momento

Angolo

CONCLUSIONSCONCLUSIONS

Most patients with UKA walked with a Most patients with UKA walked with a more normal gait pattern than patients more normal gait pattern than patients

with TKA.with TKA.Some worrisome radiographic findings Some worrisome radiographic findings

will require careful long term will require careful long term evalutation to assess UKA longevity and evalutation to assess UKA longevity and

utility.utility.

J.O. Galante (1996)J.O. Galante (1996)