BACKGROUND: In the technique of percutaneous pinning of proximal humerus fractures, the appropriate entry site and trajectory of pins is unknown, especially in the adolescent population. We sought to determine the ideal entry site and trajectory of pins. METHODS: We used magnetic resonance images of nonfractured shoulders in conjunction with radiographs of shoulder fractures that were treated with closed reduction and pinning to construct 3-dimensional computer-generated models. We used engineering software to determine the ideal location of pins. We also conducted a literature review. RESULTS: The nonfractured adolescent shoulder has an articular surface diameter of 41.3 mm, articular surface thickness of 17.4 mm and neck shaft angle of 36 degrees. Although adolescents and adults have relatively similar shoulder skeletal anatomy, they suffer different types of fractures. In our study, 14 of 16 adolescents suffered Salter-Harris type II fractures. The ideal location for the lateral 2 pins in an anatomically reduced shoulder fracture is 4.4 cm and 8.0 cm from the proximal part of the humeral head directed at 21.2 degrees in the coronal plane relative to the humeral shaft. CONCLUSION: Operative management of proximal humerus fractures in adolescents requires knowledge distinct from that required for adult patients. This is the first study to examine the anatomy of the nonfractured proximal humerus in adolescents. This is also the first study to attempt to model the positioning of percutaneous proximal humerus pins.
BACKGROUND: In the technique of percutaneous pinning of proximal humerus fractures, the appropriate entry site and trajectory of pins is unknown, especially in the adolescent population. We sought to determine the ideal entry site and trajectory of pins. METHODS: We used magnetic resonance images of nonfractured shoulders in conjunction with radiographs of shoulder fractures that were treated with closed reduction and pinning to construct 3-dimensional computer-generated models. We used engineering software to determine the ideal location of pins. We also conducted a literature review. RESULTS: The nonfractured adolescent shoulder has an articular surface diameter of 41.3 mm, articular surface thickness of 17.4 mm and neck shaft angle of 36 degrees. Although adolescents and adults have relatively similar shoulder skeletal anatomy, they suffer different types of fractures. In our study, 14 of 16 adolescents suffered Salter-Harris type II fractures. The ideal location for the lateral 2 pins in an anatomically reduced shoulder fracture is 4.4 cm and 8.0 cm from the proximal part of the humeral head directed at 21.2 degrees in the coronal plane relative to the humeral shaft. CONCLUSION: Operative management of proximal humerus fractures in adolescents requires knowledge distinct from that required for adult patients. This is the first study to examine the anatomy of the nonfractured proximal humerus in adolescents. This is also the first study to attempt to model the positioning of percutaneous proximal humerus pins.
Authors: J Burgos-Flores; P Gonzalez-Herranz; J A Lopez-Mondejar; J G Ocete-Guzman; S Amaya-Alarcón Journal: Int Orthop Date: 1993 Impact factor: 3.075
Authors: Benjamin J Shore; Daniel J Hedequist; Patricia E Miller; Peter M Waters; Donald S Bae Journal: J Child Orthop Date: 2015-02-20 Impact factor: 1.548