Utility of the Three-Point Index in the determination of reduction loss during the conservative treatment of pediatric forearm mid-third fractures.

BACKGROUND: Forearm fractures constitute approximately 40% of all pediatric fractures. Generally, in conservative treatment,a plaster cast is applied with the elbow in 90° flexion. Success of the treatment depends on theprevention of the reduction in the correct position and suitable duration of the plaster cast. Failure, or the risk of angulation within the cast, is associated with movement within the cast. The aim of this study was to evaluate the applicability of the Cast Index (CI) and Three-Point Index (TPI) measurements, which indicate the loss of reduction, in pediatric mid-third forearm fractures. The hypothesis of the study was that as edema decreases and deformity of the plaster cast occurs after fracture reduction, TPI and CI should be examined during follow-up, as they indicate shifting due to movement within the plaster cast.

METHODS: This retrospective study included a total of 48 patients, who were treated with closed reduction and long-arm plaster cast for a mid-third forearm diaphyseal fracture at our Emergency Polyclinic between March and September 2014. The mean age of the patients was 8.15±3.19 years (range, 5-14 years). Patients were excluded from the study if they had isolated radial or ulnar fracture, open fractures, concomitant fracture or systemic disease (bone metabolism disease, etc), and <10° fracture angulation in the ulna and radius on the initial radiograph and if they did not followup. TPI and CI values were calculated on anterioposterior (AP) and lateral radiographs in the Picture Archiving Communication Systems.

RESULTS: In the AP plane, compared with TPI values after reduction, statistically significant increases were observed in TPI values 10 days after reduction (p<0.01). However, no significant difference was observed between those with and without reduction loss in TPI values in the AP plane (p>0.05). Although there was a statistically significant increase in TPI values 15 daysafter reduction compared with the values immediately after reduction, a significant difference between those with and without reduction loss was observed only on lateral TPI.

CONCLUSION: In cases of pediatric forearm diaphyseal fracture, ulnar TPI examined in the lateral plane can be used in monitoring the fracture in a plaster cast applied after the reduction.