Outcome Analysis of Lateral Pinning for Displaced Supracondylar Fractures in Children Using Three Kirschner Wires in Parallel and Divergent Configuration

Abstract

Background: Supracondylar humerus fracture is the most common fracture around elbow in children. Closed reduction and percutaneous Kirschner wire (pin) fixation is the standard method of managing displaced extension type (Gartland Type II and Type III) supracondylar humerus fractures. The configuration of wires is debatable. Although two crossed K-wires are mechanically stable, there is an inherent risk of ulnar nerve injury. Lateral K-wires - parallel or divergent - are good alternative. This study was aimed at identifying the best configuration for the lateral wires.

Materials and methods: Patients with Gartland type 3 supracondylar humerus fractures were randomized by envelope method to receive closed reduction and K-wire fixation in either a parallel or divergent fashion. The patients were followed up at 3 weeks for wire removal and at 6 weeks and 3 months after surgery. Baumann's angle, functional outcome as per Flynn's criteria, and range of motion were recorded in each visit. Effect of delay in surgery was also evaluated as a secondary outcome.

Results: Nineteen patients received fixation with parallel wires and 11 patients had divergent fixation. No loss of reduction was seen in any patient at 3 months. No statistically significant difference was seen in the Baumann's angles and outcome according to Flynn's criteria irrespective of the wire configuration (divergent or parallel). Furthermore, the delay in surgery was also found not to have a significant effect on the functional outcome.

Conclusions: Both parallel and divergent K-wire configurations provide satisfactory stability when accurate reduction and adequate fixation of the fracture has been done. Based on the limited number of patients in this study, one configuration cannot be judged to be superior to the other.

Keywords: Baumann's angle; Flynn's criteria; Gartland's Type 3; Pediatrics; closed reduction; humeral fractures; humerus; supracondylar humerus fracture.

Figure 1

Intraoperative image showing a trick for achieving divergence inside the arm. the K-wires should cross each other outside for diverging inside

Figure 2

X-ray of elbow joint with arm and forearm showing (a) Preoperative radiograph with Gartland III supracondylar fracture (b and c) Immediate postoperative radiograph with divergent K-wire configuration. (d and e) Anteroposterior and lateral views after removal of K-wires 3 months postoperatively

Figure 3

X-ray of elbow joint with arm and forearm showing (a) Gartland type III supracondylar fracture. (b and c) Immediate postoperative radiograph with parallel K-wire configuration. (d and e) Anteroposterior and lateral views after removal of K-wires 3 months postoperatively