The case of 14-year-old male with low-energy tibia fracture, treated by osteosynthesis with LCP plate placement, is present. Picnodisostosis is a rare autosomal recessive lysosomal disease (1.7/million inhabitants) characterized by osteosclerosis, short stature and bone fragility and evidenced radiologically by increased bone density with permeable medular canal persistence. Due to a mutation in the gene encoding for catepsin K (1q21), enzyme responsible for the division of proteins in the bone matrix (type 1 collagen, osteonectin and osteopontin), presenting bone fragility with increased consolidation time. Diagnosis of picnodystosis was made clinically by the presence of Wormian bones in the skull, micrognathia, clavicular hypoplasia, acroosteolysis, osteosclerosis and increased bone density in long bones. Open reduction and internal fixation with tibia LCP plate was carried out, with surveillance for three months with monthly radiographic controls. The healing of the fracture was achieved within 3 months of the surgical event with reintegration into its normal activities at the same time. Picnodisostosis is a rare disease with special bone characteristics that merits treatment with special plate for osteoporotic bones obtaining good results in an acceptable time.