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Table 3 Comparison of patient characteristics between the failure and non-failure groups

From: Mid-term results and factors affecting outcome of a metal-backed unicompartmental knee design: a case series

 

Failure

Non-failure

 

Hazard Ratio

Variables

(N = 9)

(N = 71)

P value a

Ratio

95% CI

Mean age (years)

61 [8]

74 [9]

< 0.01

0.94

0.86-1.03

Male gender (percent)

44

42

1.00

0.30

0.05-1.87

Mean body mass index (kg/m2)

28 [7]

27 [4]

0.71

-

-

Obesity (body mass index ≥ 30 kg/m2) (percent)

44

20

0.11

2.13

0.34-13.3

Diagnosis (percent)

   

-

-

   Osteoarthritis

100

85

0.35

-

-

   Osteonecrosis

0

15

 

0.00

0.00

Mean pre-op objective score (points)

53 [10]

49 [9]

0.21

1.01

0.92-1.11

Mean pre-op functional score (points)

51 [5]

47 [10]

0.30

1.07

0.96-1.19

Pre-op patellar osteophytes (percent of patients)

33

46

0.38

0.27

0.07-2.01

  1. CI = confidence interval
  2. a p values were calculated based on Wilcoxon rank sum tests for continuous variables, and chi-squared or Fisher exact tests for categorical variables.