Emerging evidence has linked the long-term use of alendronate (fosamax) with subtrochanteric insufficiency fractures. However, findings to date have been anecdotal. The aims of this study were to determine the incidence of subtrochanteric insufficiency fractures and identify whether they were more prevalent following the introduction of alendronate in Australia.

All patients that presented between January 2007 and February 2009 with low- energy subtrochanteric fracture were identified. Similar data were collected between January 1995 and February 1997 as this was immediately prior to introduction of alendronate in Australia. The radiographs were examined for failure due to pre- existing insufficiency fracture. Characteristic findings were a transverse fracture line on the tension side of the femur with lateral cortical thickening immediately adjacent to the fracture. Relevant details from the history were recorded. We also separately identified all patients that presented between 2007 and 2009 with a proximal femoral fracture and determined the proportion taking alendronate.

One hundred and seventeen patients with low-energy subtrochanteric fracture were included. Seventy-nine patients presented between 2007 and 2009 and 38 presented between 1995 and 1997. Forty-one of the 79 (52%) patients were identified as having radiograph findings suggestive of underlying insufficiency fracture, whilst none were identified prior to the introduction of alendronate. Of the 41 patients with subtrochanteric insufficiency fracture, 40 (98%) had been taking alendronate and one had been taking risedronate. Twenty-nine of the 41 (71%) complained of prodromal pain in the affected femur. Eighteen of the 41 (44%) demonstrated subtrochanteric insufficiency changes on the contralateral side and 9 of 41 (22%) sustained spontaneous non-traumatic fracture during activities of daily living. Of the 38 patients without insufficiency changes, 12 (32%) had been taking alendronate. Alendronate use was therefore strongly suggestive of insufficiency fracture (sensitivity = 98%, specificity = 84%, PPV = 77%, NPV = 99%, LR+ = 6). The mean duration of alendronate use in those with insufficiency fracture was 7.1 years (95% CI, 6.6-7.6 years). The mean duration in those without was 3.2 years (95% CI, 2.6-3.8 years, P<0.0001). Three hundred and ninety eight patients presented with a low-energy proximal femur fracture between 2007 and 2009. Of these, only 52 (13%, P<0.0001) were taking alendronate.

This is the largest study in the literature on subtrochanteric insufficiency fractures and alendronate therapy. Confirming recent reports, alendronate use was strongly suggestive of subtrochanteric insufficiency fracture. Our findings provide the most compelling evidence to date of the potential long-term sequelae of alendronate but more research is needed before definitive conclusions can be made.

Böhler’s historical tuber-joint angle of the calcaneus has been used since 1931. Surprisingly, there is a paucity of literature on the topic. The aims of this study were to confirm the normal range for Böhler’s angle and determine the angle with the highest accuracy in the diagnosis of calcaneal fractures.

A retrospective cohort study was performed. Data were obtained from The St George Hospital digital Picture Archival and Communication System (PACS) and through a review of medical records. The study cohort comprised 212 consecutive patients diagnosed with calcaneal fractures on CT scan, spanning a five-year period from April 2003 to March 2008. An additional 212 patients with normal lateral foot radiographs were used to determine the normal range. Böhler’s angle was measured by two independent observers on lateral xray using the digital angle tool from PACS. Data were analysed using Stata 8 statistical software package.

This is the largest study to our knowledge that examines the diagnostic accuracy of Böhler’s angle in fractures of the calcaneus. Contrary to many texts but true to Böhler’s assertions, the mean Böhler’s angle in patients without calcaneal fracture was 29.4 degrees (95% CI, 28.9–30.0 degrees). In this group there was no difference in Böhler’s angle between male and female patients (p> .05), left and right feet (p> .05) or across age (ANOVA, p> .05). In those patients with calcaneal fractures, a Böhler’s angle below 25 degrees was moderately predictive of calcaneal fracture (sensitivity = 100%, specificity = 82%, PPV = 85%, NPV = 100%, LR+ = 5), an angle below 23 degrees was highly predictive of calcaneal fracture (sensitivity = 100%, specificity = 89%, PPV = 90%, NPV = 100%, LR+ = 9) and an angle below 21 degrees was strongly suggestive of calcaneal fracture (sensitivity = 99%, specificity = 99%, PPV = 99%, NPV = 99%, LR+ = 110). A Böhler’s angle of less than or equal to 20 degrees had the highest diagnostic accuracy as there were only two false negatives and one false positive from a total of 424 patients.

A Böhler’s angle of 20 degrees or less is highly accurate in determining the presence or absence of calcaneal fracture. These findings are of particular importance when fracture is uncertain as it gives the surgeon a definitive reference point when using Böhler’s angle for assessment of fracture of the calcaneus.