Intraoperative sonography may reduce the risk of extensor pollicis longus tendon injury during dorsal entry elastic intramedullary nailing of the radius in children

Extensor pollicis longus tendon (EPL) injury is a potential complication of dorsal entry radial elastic nailing technique in children. The aim of this study was to investigate if intraoperative ultrasonographic guidance can reduce the risk of (EPL) injury. Correlation between sonographic and operative findings were examined first in 6 adult cadavers. Position of Lister's tubercle, EPL, and extraosseal end of the elastic nail were detected by ultrasound imaging during a minimally invasive dorsal entry nailing. Radial slope of Lister's eminence was determined as a safe and easily identifiable entry point for opening the medullary canal. Extraosseal ends of the nails were bended in a slight radial direction and cut immediately beneath the skin in a maximally palmar-flexed wrist position. Cadaveric dissections followed our procedures all correlated with ultrasonographic findings, we have not seen tendon damage, obstruction or friction by the implant's end. After cadaveric experiments, we began using intraoperative sonography for monitoring elastic nail insertion in pediatric radial fractures. Between January 2015 and November 2016, 77 pediatric closed diaphyseal radial fractures were operated by dorsal approach ESIN under intraoperative sonographic checking. Procedures were executed by 2 orthopedic surgeons experienced in ESIN technique with basic musculoskeletal ultrasonographic qualifications. Sonographic identification of EPL and Lister's tubercle in the transverse view was possible in all cases. Determination of the position of the nail end to EPL was also possible in all cases. Mean distance of the transverse view center of the EPL and nail was 0.49 cm (range 0.3–0.62 cm, SD = 0.66). Based on the sonographic transverse view, the operator decided repositioning the nails by 2 patients. We have not found EPL injury postoperatively. All patients were followed for at least 12 months after operations. Nails were removed in all children without further complications. Intraoperative sonography helps determining optimal insertion point and the risk of EPL injury may be reduced during dorsal entry approach. Although the procedure is relatively easy, authors take note that surgical and sonoanatomic knowledge, basic sonographic skills and experience in the ESIN technique are equally necessary for its successful application. A greater number of cases is necessary to confirm our initial promising experiences.