Treatment of displaced supracondylar humeral fractures in children by humero-ulnar external fixation

Humero-ulnar external fixation has been proposed to treat complex supracondylar humeral fractures in children. It facilitates fracture reduction and reduces the risk of ulnar nerve lesion, which can occur after cross pinning. In a ten year period, 28 children have been operated on in our centre by humero-ulnar external fixation, for Lagrange-Rigault stages III and IV supracondylar humeral fractures. The data about fracture management and early follow-up were obtained from our medical database. The long-term evaluation was done at a minimum six months' follow-up. The range of motion and carrying angle measurements were classified according to Flynn. The final X-rays were evaluated for quality of reduction, presence of malunion, late infection signs, osteo-arthritis and myositis ossificans. The elbow function was evaluated by Mayo Elbow Performance Index (MEPI), Disabilities of the Arm, Shoulder and Hand (DASH) or modified DASH scores. The treatment was well tolerated by children and parents. There was no neurological complication related to the insertion of the pins, and no Volkmann syndrome. The median duration of external fixation was 33.5 days. Twelve patients were reviewed after a median follow-up duration of seven years (mean, 7.5 years; range, 3-21 years). One child had a refracture, three years after his original fracture, which was treated non-operatively. This case ended up in a cubitus varus deformity with a pronation deficit. All other patients had excellent clinical and radiological results. For the treatment of complex supracondylar humeral fractures in children, humero-ulnar external fixation is a good alternative to lateral or crossed pinning. The advantages are the ease to obtain the reduction, the absence of neurological risk to the ulnar nerve and the possibility to obtain good stabilisation of the fracture with moderate elbow flexion.