Percutaneous Pinning for Surgical Neck Fracture of the Humerus. Results of 24 Cases at our Hospital.

We studied elderly patients with malunion, pseudoarthrosis or delayed union, as well as those requiring further operation after percutaneous pinning for surgical neck fracture of the humerus. Twenty-four cases of surgical neck fracture of the humerus were treated by percutaneous pinning at our hospital from 1995 to 1999. The average age was 76.9 years, and consisted of 21 females and 3 males. The pinning methods were conventional antegrade percutaneous pinning (19 cases) and retrograde intramedullary pinning with curved Kirschner wires (5 cases). With the antegrade procedure, four cases resulted in malunion, causing varus deformity of the Numeral neck, and two cases showed pseudoarthrosis or delayed union. With the retrograde procedure, one case showed varus deformity and another case delayed union.The common cause of malunion and pseudoarthrosis in the antegrade procedure is incorrect reduction in percutaneous pinning, which causes varus deformity and separates the fracture site. On the other hand, retrograde procedure enables good reduction, but the Kirschner wires used tend to slip out distally, which causes malunion or delayed union. We conclude that retrograde intramedullary pinning should be performed using more multiple-curved Kirschner wires or any other device to prevent slipping-out.