The most recent literature reports that the incidence of atypical fractures is 0.6 %. However, taking into consideration only the fracture locations suitable for the identification of atypical fractures, the percentage rises to 5 %. To date, there is still no clarity on the exact etiology of fractures even if it seems to be related to a bone mineral component alteration.

Teriparatide is a synthetic polypeptide hormone that contains the 1-34 aminoacid fragment of the recombinant human parathyroid hormone. It has been approved for the treatment of postmenopausal women with osteoporosis who are at high risk for sustaining a fragility fracture. It has been shown that teriparatide also accelerates fracture healing by improving the biomechanical properties of the fracture callus, increasing endochondral ossification and bone remodeling in animal models. This effect has been observed in several case reports. Fracture healing disorders negatively affect the patient's quality of life and result in high healthcare costs, as a second surgery is required to stabilize the fracture and stimulate bone biology. Future biotechnologies that accelerate fracture healing may be useful tools. We present a case report of delayed union of a femoral fracture treated with teriparatide. She was diagnosed with right distal metaphyseal femoral fracture on total knee arthroplasty. She underwent surgery at our center consisting of ORIF with lateral femoral locking plate in October 2011. Radiologic controls at 5 and 7 months did not show any signs of healing. After 2 months of treatment with teriparatide, the X-ray showed the presence of bone bridges and a decreased gap between fragments and a different aspect of neoformed bone. After 3 months of treatment, healing was complete. Our case report seems to confirm the possible effect of TPTD as bone induction through a more rapid healing of fractures. The TPTD could have a potentially important role in treating some forms of nonunion and delay in consolidation. Thus, one could hypothesize the possibility of a medical treatment with TPTD both as a preventive way and also as a support to the synthesis in high risk of nonunion fractures and complexed fractures in osteoporotic bone.

SummaryPurpose. Is it possible a correlation between some periprosthetic femoral fractures and atypical fractures? Case. We present a case of a 77-year-old woman with atypical periprosthetic femoral fracture. The patient had a history of long-term bisphosphonate use. We performed an open reduction, a synthesis of the fracture and a histological exam. The patient stopped the bisphosphonate (BF) therapy. Three months later, before starting the teriparatide treatment, the patient had a re-fracture so we did a second osteosynthesis and began a teriparatide therapy. After six months, the radiography showed a bone healing at the fracture site. Result. The histological examination confirmed the diagnosis of atypical femoral fracture. Conclusion. At first, the fracture showed a delayed union which led to a new surgery, as often happens in BF-related atypical fractures. Appropriate treatment (BF suspension and teriparatide beginning) permitted fracture healing. The atypical characteristic of the fracture was confirmed by histological exam. Some periprosthetic femoral fractures in patients treated with BF, especially in long time therapies, should be suspected as atypical fractures and a specific medical treatment should be performed, as well as a correct surgical treatment.

Atypical femoral fractures can be subsequent to a long-term biphosphonates treatment; they have a high frequency of delayed healing. The authors describe a femoral pseudoarthrosis of an atypical fracture treated with intramedullary nailing in a female after prolonged alendronate therapy. Atypical femoral fractures can be subsequent to a long-term biphosphonates treatment even if, in the literature, there is no clarity on the exact pathogenetic mechanism. The Task Force of the American Society for Bone and Mineral Research described the major and minor features to define atypical fractures and recommends that all the five major features must be present while minor features are not necessary. Another controversial aspect regarding the atypical femoral fractures is the higher frequency of the delayed healing that can be probably related to a suppressed bone turnover caused by a prolonged period of bisphosphonates treatment. This concept could be corroborated by the Spet Tc exam. In the case of a pseudoarthrosis, there is not a standardization of the treatment. In this report, the authors describe a femoral pseudoarthrosis of an atypical fracture treated with intramedullary nailing in a female after prolonged alendronate therapy; the patient was studied with clinical, bioumoral end SPECT-Tc exam of both femurs. Many studies show the relationship between bisphosphonates and the presence of atypical fractures. These fractures should be monitored more closely due to the risk of nonunion and they require considering an initial treatment with pharmacological augmentation to reduce the complications for the patient and the health care costs.

SummaryAn accurate diagnosis of osteoporosis and a proper treatment are today recognized to be the most important facts for prevention and for a correct arrangement and treatment of fragility fractures. In the text the Authors describe a case of severe osteoporosis aggravated by 2 femur fractures and 2 periprosthetic fractures occurred in 2 months. In such cases the orthopaedic surgeon needs to formulate first a clinical osteoporotic pattern, than its treatment together with a surgery suitable choice, that has to take into consideration of the bone structural characteristics. In the case described one can note that fractures healing occurred thanks to both an improvement in surgical techniques and antiosteoporotic pharmacological support; in the specific case the Authors used strontium ranelate for its osteoinductive capacity. In our opinion is crucial that the treatment used by orthopaedic surgeons is not related only to the "by-hand" treatment but take into consideration both the underlying disease and the possibility of positively affect bone healing with specific drug therapy.