[Atypical fracture of metatarsal bone in a patient with multiple myeloma who was treated long-term with bisphosphonates]. / Atypická fraktura metatarzální kosti u pacienta s mnohocetným myelomem, který byl dlouhodobe lécen bisfosfonáty.

The first reports found in professional literature on the use of bisphosphonates as a treatment date back to 1972. We found the first report on the use of a bisphosphonate comprising nitrogen in its molecule in a publication from 1990. Some of the adverse effects of the particular types of bisphosphonates were described in the registration studies. At least two serious adverse effects of this group of medicines had not been described until 2000. We found the first description of jaw osteonecrosis in relation to the longterm application of bisphosphonates in a publication from 2002 and we found the first description of an atypical bone fracture originating without a corresponding traumatic event in a location with no presence of an osteolytic focus in an article from 2006. These so  called atypical fractures, which are also called fractures without a corresponding traumatic event (low energy fractures), have been described to have occurred in femurs, in the pelvis and less frequently in the metatarsal area. "Atypical fractures" are linked to longterm administration of bisphosphonates, which significantly increases the bone density and impedes osteolysis but it simultaneously increases the fragility of bones and decreases their flexibility. The definition of an atypical fracture of the skeleton emphasises the fact that such fractures occur with an inadequately minimal force (energy) in the aforementioned predilection locations. In the following text we are describing a patient who has been treated for a multiple myeloma with an atypical fracture of the Metatarsal bone 2. This fracture occurred during a regular walk without any excessive load and the patient could not recall any corresponding injury or longer walking. The patient had been administered bisphosphonates for 34 months before the atypical metatarsal fracture occurred. The metatarsal bone fracture was treated through a nonweight  bearing regime for the sole and the pain diminished within a single month. In comparison with the published data of atypical fractures, our case concerns a short interval between initiation of the bisphosphonate administration and the occurrence of the atypical fracture. In the available literature these fractures are described after more than a five year application of a bisphosphonate. New pain in the bearing skeleton in patients treated with bisphosphonates are therefore always subject to an imaging examination among others to exclude an atypical fracture due to an increased fragility of the bone.