Table 4.

Effect modification of patients with concurrent fibular pseudarthrosis on the risk of ankle valgus compared with those without concurrent fibular pseudarthrosis, stratified by NF-1, CPT location, age of patient undergoing surgery and LLD

	OR (95% CI)	P value
CPT location
Proximal 2/3	1.580 (0.563 to 4.431)	0.3850
Distal 1/3	2.195 (1.154 to 4.175)	0.0166
Age of patient undergoing surgery (years)
<3	2.485 (1.188 to 5.200)	0.0157
≥3	1.392 (0.604 to 3.208)	0.4370
LLD (cm)
<2	2.478 (1.225 to 5.015)	0.0116
≥2	1.035 (0.394 to 2.723)	0.9441
NF-1
No	0.981 (0.335 to 2.871)	0.9725
Yes	2.836 (1.517 to 5.303)	0.0011

Above models adjusted for: sex, BMI, fracture age, age of patient undergoing surgery, surgery method, NF-1, LLD, CPT location, and fibular cystic change. In each case, the model was not adjusted for stratification variable itself.

BMI, body mass index; CPT, congenital pseudarthrosis of the tibia; LLD, limb-length discrepancy; NF-1, type 1 neurofibromatosis.