Teriparatide treatment in an adult patient with hypophosphatasia exposed to bisphosphonate and revealed by bilateral atypical fractures
Teriparatide treatment in an adult patient with hypophosphatasia exposed
to bisphosphonate and revealed by bilateral atypical fractures
Morgane Righetti 1,2, Jean Wach 1,2, Romain Desmarchelier 2,3,Fabienne Coury 1,2
1. Service de Rhumatologie, Centre Hospitalier Lyon Sud, Pierre-Bénite, / 2. Université de Lyon I, / 3. Service d’orthopédie, Centre Hospitalier Lyon Sud, Pierre-Bénite
Atypical femoral fractures (AFF) are defined as atraumatic or low-trauma fractures located in the subtrochanteric region or femoral shaft. AFF have been mainly reported in patients taking bisphosphonates as well as in patients on dénosumab, but other conditions promote them.
We report the case of a 67-year-old female with osteoporosis treated by alendronate during ten years and referred to our department for thigh pain associated with femoral cortical hyperfixation in bone scintigraphy.
Radiographies showed femoral atypical fractures. Serum levels of total and bone-specific alkaline phosphatase (ALP) were low. In order to accelerate bone healing, teriparatide was introduced because of persistent bone pain without fractures healing. One year later, pain and functional difficulty have decreased, and both serum total and bone-specific alkaline phosphatase levels were normalized.
In view of this history of recurrent fractures, atypical fractures, early spontaneous loss of permanent teeth and low serum total and bone-specific alkaline phosphatase levels, the diagnosis of hypophosphatasia has been considered and confirmed by genetic research. AFF may also occur in patients with no exposure to anti-resorptive therapies, such as in conditions associated with abnormal bone structures, as hypophosphatasia.
Hypophosphatasia is a rare inherited bone metabolism disorder. A few case reports have related adult hypophosphatasia treated by teriparatide with a good efficacy on bone pain and consolidation but with mixed results on biological markers. Teriparatide may be a treatment option in adult hypophosphatasia which lacks treatment.
It is important to check ALP levels among our osteoporotic patients and before introducing bisphosphonate treatment. Low ALP levels have to be considered. An evocative history of hypophosphatasia has to be searched in that case. It is significant because this condition contraindicates bisphosphonate treatment which can aggravate or declare the symptoms.