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Recursive Partitioning Tree of Altman for the Diagnosis of Osteoarthritis of the Knee Using Clinical and Laboratory Data

Purpose: To evaluate a patient for idiopathic osteoarthritis of the knee using the recursive partitioning model of Altman with clinical and laboratory data.

Description

Altman used recursive partitioning in the diagnosis of idiopathic osteoarthritis of the knee. The diagnosis can be made based on clinical and laboratory data. The author is from the University of Miami and Miami Veterans Administration Medical Center.


 

NOTE: The recursive partitioning is similar to CART (classification and regression tree) analysis.

 

Patient selection:

(1) presence of knee pain

(2) absence of a condition predisposing to degenerative arthritis (see Table I, page 33)

 

Parameters:

(1) synovial fluid (SF) findings

(2) rheumatoid factor (RF)

(3) crepitus

(4) bony enlargement

(5) age

 

Synovial fluid (SF) findings seen in osteoarthritis

(1) clear

(2) viscous

(3) WBC count < 2,000 per µL.

 

SF Fluid

RF

Crepitus

Bony Enlarge

Age

Group

0

 

 

 

 

A

1 or 2

positive

 

 

 

B

3

positive

 

 

 

C

1 or 2

negative

N

N

 

D

3

negative

N

Y

 

E

3

negative

N

 

 

F

1, 2 or 3

negative

Y

 

<= 42

G

1, 2 or 3

negative

Y

 

>= 43

H

 

 

Group

Diagnosis

A

no osteoarthritis

B

no osteoarthritis

C

osteoarthritis

D

no osteoarthritis

E

no osteoarthritis

F

osteoarthritis

G

no osteoarthritis

H

osteoarthritis

 

Performance:

• The sensitivity is 88% and the specificity is 93%.

 

Age and ESR can be used as a surrogate marker if synovial fluid data is lacking.

 

Age

RF

Crepitus

Bony Enlarge

ESR

Group

<= 49

 

 

 

 

A

>= 50

positive

 

 

> 14 mm

B

>= 50

positive

 

 

<= 14 mm

C

>= 50

negative

N

Y

 

E

>= 50

negative

N

 

 

F

>= 50

negative

Y

 

 

H

 

Morning stiffness can be used as surrogate marker for rheumatoid factor.

 

SF Fluid

Morning Stiffness

Crepitus

Bony Enlarge

Age

Group

0

 

 

 

 

A

1 or 2

> 30

 

 

 

B

3

> 30

 

 

 

C

1 or 2

<= 30

N

N

 

D

3

<= 30

N

Y

 

E

3

<= 30

N

 

 

F

1, 2 or 3

<= 30

Y

 

<= 42

G

1, 2 or 3

<= 30

Y

 

>= 43

H

 


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Specialty

Objective

ICD-10