Table IV.

Construct validity of ankle radiological outcome measures.

Outcome	Novice (residents < 10 cases)	Intermediate (residents ≥ 10 cases)	Total	p-value*
Total, n	147	88	235
Talocrural angle, °				0.517
Number	124	83
Mean (SD; range)	78.1 (3.5; 68.6 to 88.0)	77.8 (0.4; 70.3 to 87.7)	78.0 (3.4; 68.6 to 88.0)
Medial clear space, mm
Number	130	83		< 0.001
Mean (SD; range)	3.8 (1.3; 1.5 to 8.3)	3.0 (1.2; 0.1 to 8.6)	3.5 (1.4; 0.1 to 8.6)
Medial malleolar displacement, mm
Number	130	83	213	0.001
Mean (SD; range)	1.8 (2.3; 0 to 13.1)	0.8 (1.3; 0 to 7.3)	1.4 (2.0; 0 to 13.1)
Lateral malleolar displacement, mm
Number	130	83	213	< 0.001
Mean (SD; range)	2.2 (1.9; 0 to 7.8	1.3 (1.4; 0 to 8.1)	1.9 (1.8; 0 to 8.1)
Tibiofibular clear space, mm
Number	130	83	213	< 0.001
Mean (SD; range)	5.6 (1.8; 2.0 to 10.7)	4.1 (1.4; 0.5 to 8.3)	5.0 (1.8; 0.5 to 10.7)
PBA global rating scale (continuous)
Number	23	19	42	< 0.001
Mean (SD; range)	2.1 (0.3; 2 to 3)	3 (0.5; 2 to 4)	2.5 (0.6; 2 to 4)
PBA global rating scale (categorical), n (%)				0.001
2	21 (91)	2 (11)	23 (55)
3	2 (9)	15 (79)	17 (41)
4	0 (0)	42 (70)	2 (5)

^*Independent-samples t-test comparing means; chi-squared test where cells > five cases and, Fisher’s exact test where cells ≤ five cases.

PBA, procedure-based assessment; SD, standard deviation.