LATERAL CONDYLAR FRACTURE OF THE HUMERUS FOLLOWING POSTTRAUMATIC CUBITUS VARUS

Posttraumatic cubitus varus is widely regarded as just a cosmetic defo rmity. Six cases of lateral condylar fracture of the humerus in childr en with preexisting cubitus varus due to prior elbow fracture are pres ented. Five occurred following malunited extension-type supracondylar fractures of the humerus; the other occurred following a lateral condy lar fracture complicated by lateral overgrowth. All cases were treated by anatomic reduction (two closed, four open) and percutaneous pinnin g of the lateral condylar fracture. Three of the six cases subsequentl y underwent supracondylar osteotomy of the distal humerus to correct t he underlying varus malalignment. Biomechanical analysis suggests that both the torsional moment and the shear force generated across the ca pitellar physis by a routine fall are increased by varus malalignment. Posttraumatic cubitus varus may predispose a child to subsequent late ral condylar fracture and should be viewed as more than just a cosmeti c deformity.