Treatment of unstable forearm fractures at the metaphyseal-diaphyseal junction in children: antegrade ESIN vs. transepiphyseal intramedullary K-wire fixation

Abstract

Background: Treatment of unstable forearm fractures in the metaphyseal-diaphyseal junction (MDJ) zone is still a matter of debate. Major drawbacks of all types of fixations include either invasiveness, technical impracticality, or lack of acceptance by patients. This study reports results after antegrade ESIN (a-ESIN) compared to transepiphyseal intramedullary K-wire (TIK) for unstable MDJ forearm fractures.

Methods: The MDJ of the forearm was defined as the square over the joints of both forearm bones subtracted with the square over the metaphysis of the radius alone. The data of 40 consecutive patients < 16 years of age who were treated either by a-ESIN (later treatment period) or TIK (early treatment period) for an unstable MDJ forearm fracture at a single high-volume pediatric trauma center were retrospectively analyzed.

Results: The average age was slightly lower in the first group (TIK = 7.42 years; a-ESIN = 10.5 years). An additional ulna fracture was found in 50% of cases and was treated with a classic antegrade ESIN in 10/20 (TIK) and 6/20 cases (a-ESIN). Additional plaster cast immobilization was performed in all cases with TIK and in three cases with a-ESIN. After TIK, no complication, malalignment, or functional limitation occurred. After a-ESIN, 19/20 patients had an event-free course with stable retention and healing without axial malalignment. In one case, a temporary sensor dysfunction occurred. The same patient suffered a refracture two months after the original trauma, which required a closed reduction. Metal removal was performed after 84 days (TIK) and 150 days (a-ESIN). The outcome in all patients was good.

Conclusion: Both a-ESIN and TIK are minimally invasive procedures that are technically easy to perform. Both methods are safe and lead to a complete restoration of the forearm's range of motion. The decisive advantage of a-ESIN is the possibility of postoperative immobilization-free rehabilitation.

Keywords: Antegrade ESIN; Diametaphysis; Elastic stable intramedullary nailing; Forearm fracture; K-wire; Metaphyseal-diaphyseal junction; Pediatric trauma.

Fig. 1

Definition of the metaphyseal diaphyseal junction area. For this study, the authors used the square over both radius and ulna and subtracted the square over the radial growth plate alone to define the metaphyseal diaphyseal transition area and to have a reproducible basis for evaluation. M = metaphysis of the radius. MDJ = metaphyseal-diaphyseal junction

Fig. 2

Thompson’s approach. Approach to the radius as proposed by Thompson in 1918. Landmarks are (proximal) the lateral epicondyle of the humerus and (distal) the dorsoradial (Lister’s) tubercle. In the middle of a line connecting these landmarks, a muscular “soft spot” can be identified and used for an inch-long incision for antegrade ESIN

Fig. 3

Antegrade ESIN in a 10-year-old boy. Antegrade ESIN in a 10-year-old boy. X-ray at admission (A, B), during surgery (C, D) and before metal removal after 5 months (E, F)

Fig. 4

Implantation technique using Thompson’s approach. Implantation technique using Thompson’s approach in a displaced fracture located at the metaphyseal diaphyseal junction of the radius: X-ray at admission (A), during surgery (B, C) and before metal removal (D, E). Active scar at the dorsal aspect of the patient’s forearm following skin incision at the “soft spot” (F)