Lateral fixation: an alternative surgical approach in the prevention of complete atypical femoral fractures

Abstract

Little evidence is available on how to treat incomplete atypical fractures of the femur. When surgery is chosen, intramedullary nailing is the most common invasive technique. However, this approach is adopted from the treatment of other types of ordinary femoral fracture and does not aim to prevent the impending complete fracture by interrupting the mechanism underlying the pathology. We suggest a different surgical approach that intends to counteract the underlying biomechanical conditions leading to a complete atypical fracture and thus could be better suited in selected cases. Here, we share an alternative surgical approach and present two cases treated accordingly.

Keywords: Atypical fracture; Bisphosphonate; Femoral fracture; Fracture prevention; Osteoporosis.

Fig. 1

a Schematic drawing of an incomplete fracture confined to the lateral side of a femur with a centered axis (no curvature). Tensile forces applied to the lateral cortex are outlined (arrows). b Schematic drawing of the same femur as in a that was provided prophylactic treatment with an intramedullary nail (IMN) to prevent future completion of the atypical fracture

Fig. 2

a Schematic drawing of a curved femur with incomplete fracture confined to the lateral side of the bone. Note: increased tensile forces (arrows) are applied to this femur compared with one with a centered axis (Fig. 1a). Because of the prominent curvature of this femur, it would be difficult to insert an intramedullary nail (IMN) (b) without the risk of causing further injury to the architecture of the bone. b The curved femur with an incomplete fracture that was provided prophylactic treatment with lateral fixation according to the present approach. The plate is positioned with six bicortical screws

Fig. 3

a An 80-year-old female sustained an incomplete fracture of her right femur. Before the fracture, she had received 5 years of treatment with alendronic acid because of a high dose of corticosteroids for rheumatic disease. She recalled enduring 6 months of increasing pain from her right thigh before seeking medical advice. b Surgery was selected as the preventive treatment of choice. Bisphosphonate treatment was discontinued before surgery. Lateral fixation was performed because of the curvature of the femur (femoral angle approximately 10°). Full weight bearing was allowed postoperatively. Radiographic examination after surgery revealed no further propagation of the fracture

Fig. 4

a An 83-year-old female sustained an incomplete fracture of her right femur without any history of previous bisphosphonate use. She recalled having 12 months of increasing pain from her right thigh before seeking medical attention. b Surgery was selected as the preventive treatment. Because of the curvature of the femur (femoral angle approximately 10°), lateral fixation was performed. A biopsy of the fracture site was taken to exclude other related conditions that might have contributed to the development of a stress fracture despite femoral bow. The defect created by the biopsy showed callus formation after 3 months and complete recortication after approximately 18 months. Full weight bearing was allowed postoperatively