Table 1 Mean ± standard deviation participant demographics, joint space measurement, and knee joint health at baseline and 2-year follow-up.

Age (yr)

37.7 ± 6.6

39.7 ± 6.7

 < 0.01*

Stature (m)

1.78 ± 0.05

1.78 ± 0.05

0.73

Mass (kg)

87.7 ± 17.8

88.7 ± 18.7

0.17

Level of limb loss

Transtibial: 9

Transfemoral: 8

Residual limb length (cm)

21.5 ± 8.76

Time since injury (month)

119.8 ± 89.3

Time since surgery (month)

108.2 ± 89.3

Time since first prosthesis (month)

106.2 ± 90.0

Time between visits (month)

26.6 ± 3.2

Medial joint space (mm)^a

5.83 ± 1.01

5.59 ± 1.18

0.46

Lateral joint space (mm)^a

6.59 ± 1.13

6.09 ± 0.74

0.01*

Medial patellofemoral joint space (mm)^b

8.14 ± 2.57

7.00 ± 1.96

0.35

Lateral patellofemoral joint space (mm)^b

7.93 ± 2.49

6.61 ± 1.66

0.20

Kellgren–Lawrence grade; n(%)^b

 0

7 (58.3%)

–

 < 0.01*

 1

3 (25.0%)

7 (58.3%)

0.03*

 2

1 (8.3%)

3 (25.0%)

0.22

 3

1 (8.3%)

2 (16.7%)

0.51

 4

–

–

–

% with KL ≥ 2

2 (16.7%)

5 (41.7%)

0.28

Outerbridge—Medial^c

 0

4 (50.0%)

5 (62.5%)

 1

1 (12.5%)

1 (12.5%)

 2

–

–

 3

2 (25.0%)

1 (12.5%)

 4

1 (12.5%)

1 (12.5%)

Outerbridge—Lateral^c

 0

6 (75.0%)

4 (50.0%)

 1

1 (12.5%)

3 (37.5%)

 2

1 (12.5%)

–

 3

–

–

 4

–

1 (12.5%)

Outerbridge—Patellofemoral^c

 0

3 (37.5%)

1 (12.5%)

 1

1 (12.5%)

1 (12.5%)

 2

–

5 (62.5%)

 3

2 (25.0%)

–

 4

2 (25.0%)

1 (12.5%)