Chen et al. evaluated the effect of postoperative rotational malalignment in Gartland type III/IV paediatric supracondylar humerus fractures treated with closed reduction and percutaneous K-wire fixation. In this retrospective study of 295 children, malrotation was quantified using the lateral rotation percentage (LRP) on postoperative lateral radiographs.
Patients were divided into four groups according to LRP: ≤10%, 10–20%, 20–30%, and >30%. While Baumann angle, carrying angle, and forearm rotation were not significantly different between groups, higher malrotation was associated with reduced shaft-condylar angle, delayed K-wire removal, decreased elbow flexion, and lower functional scores.
The most clinically relevant finding was that elbow flexion and functional outcomes deteriorated particularly when LRP exceeded approximately 20%. ROC analysis identified 26.5% LRP as the maximum acceptable threshold for residual rotational deformity, with high sensitivity and specificity.
Clinical relevance:
A small amount of residual malrotation after fixation of paediatric supracondylar humerus fractures may be tolerated, but excessive malrotation should not be ignored. An LRP above 26.5% may predict worse elbow function, especially loss of flexion.
OrthoRico Take-home Message:
In Gartland type III/IV paediatric supracondylar humerus fractures, postoperative malrotation matters.
LRP >26.5% = increased risk of poorer functional outcome.