Older age and multi-joint external fixator are two risk factors of complications in ulnar lengthening in children with hereditary multiple exostosis

Table 2 Clinical results of group A

Subject	Preoperative	FFU	Wilcoxon test		P value of Spearman correlation analysis
Subject	Preoperative	FFU	Z	P	Age	Gender	Follow-up	Type	IL^a
US (mm)	23.15 ± 5.55	0.70 ± 2.49	− 4.546	< 0.05	0.555	0.855	0.239	0.097	Na
RAA (°)	32.30 ± 4.07	22.22 ± 2.28	− 4.550	< 0.05	0.807	0.193	0.184	0.440	< 0.05
CS (%)	70.37 ± 6.70	26.70 ± 3.42	− 4.547	< 0.05	0.863	0.951	0.828	0.558	< 0.05
MEPS	74.07 ± 3.68	94.26 ± 6.46	− 4.541	< 0.05	0.367	0.643	0.080	0.698	0.946
Elbow flexion (°)	104.26 ± 4.94	130.44 ± 5.18	− 4.569	< 0.05	0.263	0.975	0.625	0.460	0.380
Forearm pronation (°)	71.11 ± 3.76	83.52 ± 3.34	− 4.592	< 0.05	0.233	0.403	0.099	0.730	0.308
Forearm supination (°)	83.33 ± 3.67	84.07 ± 3.68	− 2.000	< 0.05	0.384	0.320	0.790	0.670	0.973
Complications (n)
Deviation of ulna axis		0 case
Poor regenerate bone formation		0 case
Neurovascular complications		0 case
Fracture after fixator removal		0 case
Pin site infection		3 cases
Redislocation of radial head		0 case
Recurrence of exostosis		0 case

Abbreviations: US ulnar shortening, RAA radial articular angle, CS carpal slip, MEPS Mayo Elbow Performance Score, FFU final follow-up, IL improved length, Na not available, ^aIL = |US(preoperative)-US(FFU)|. P value < 0.05 statistically significant

ISSN: 1749-799X