Disturbed remodeling and delayed fracture healing in pediatric pycnodysostosis patients

J Orthop. 2019 Apr 15;16(5):373-377. doi: 10.1016/j.jor.2019.03.022. eCollection 2019 Sep-Oct.

Abstract

Pycnodysostosis is an autosomal recessive disease caused by a gene mutation leading cathepsin K deficiency. Pathological fractures of the long bones are common, but guidelines on fracture treatment in these patients are still lacking. We have treated 5 fractures in 2 pediatric pycnodysostosis patients. We hypothesize that pycnodysostosis patients have an incomplete remodeling process in fracture healing because of cathepsin K deficiency. Therefore, to minimize the role of endochondral bone formation (indirect) after a fracture, it seems prudent to strive for direct bone healing (intramembranous) instead of indirect bone healing. Open reduction with internal fixation should be the goal.

Keywords: Endochondral; Fracture; Intramembranous; Osteoclasts; Pycnodysostosis; Remodeling.