Pauwels Osteotomy for Femoral Neck Nonunion in Two Adult Siblings with Osteogenesis Imperfecta

This is a retrospective review of two adult siblings with osteogenesis imperfecta (OI) type III (according to Sillence classification), who sustained a spontaneous femoral neck fracture and subsequent nonunion. The diagnosis of OI in these two patients was made based on clinical, radiological and genetic findings. The fracture was most likely caused by femoroacetabular impingement secondary to OI induced acetabular protrusio. A valgus osteotomy according to Pauwels'principles and fixation of the osteotomy and nonunion with a locking plate resulted in healing despite compromised bone quality and limited bone stock. Long-term follow up (4.5 years and 6.5 years, respectively) is provided. When treating this difficult problem, improving the mechanobiological environment and decreasing the femoroacetabular impingement by a Pauwels type osteotomy should be considered.