Changing pattern of femoral fractures in osteogenesis imperfecta with prolonged use of bisphosphonates.

PURPOSE: Osteogenesis imperfecta (OI) has been treated with bisphosphonates for many years, with some clear clinical benefits. In adults, there are reports of a new pattern of atraumatic subtrochanteric fractures with bisphosphonate treatment. This study assesses if bisphosphonate treatment leads to an altered pattern of femoral fractures. METHODS: Retrospective review of imaging for a cohort of 176 bisphosphonate-treated OI patients to identify the locations of femoral fractures over a two-year period, as compared to a historical control group managed pre-bisphosphonates. RESULTS: Sixteen femoral fractures were identified in this time period in the bisphosphonate-treated group. All but two were within the subtrochanteric region. In comparison, the historical group-composed of 26 femoral fractures-had a more widespread fracture pattern, with the most frequent location being the mid-diaphysis. Many of the subtrochanteric fractures in the treatment group occurred with minimal trauma. CONCLUSIONS: It appears that concerns over the treatment of the adult osteoporotic population with bisphosphonates are amplified and mirrored in OI. It is possible that the high bending moments in the proximal femur together with altered mechanical properties of cortical bone secondary to the use of this group of drugs increase the risk of this type of injury, which warrants further modification of surgical management of the femur.

Do we need to replace the patella in knee arthroplasty for rheumatoid disease?

We have examined the anterior knee function in two patient groups who had undergone primary knee arthroplasty without patellar resurfacing to identify differences for osteoarthrosis compared with rheumatoid disease. We identified two consecutive series of patients who had undergone knee replacement surgery for either osteoarthritis or rheumatoid disease between 1992 and 1994 under the care of a single surgeon using the same implant and surgical technique. There were 90 patients in each group. All were examined and asked to complete a questionnaire so as to determine Hospital for Special Surgery (HSS) score, Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score, Bartlett patellar score and a Visual Analogue score (VAS) for any persistent anterior knee pain at rest. We failed to identify any significant differences in terms of anterior knee function between these two groups of patients. The re-operation rate was similar for both groups. It would appear that primary knee replacement for rheumatoid disease is met with a similarly good outcome for anterior knee function despite absence of patellar resurfacing. We would question the contention that patellar resurfacing is necessary for patients undergoing knee replacement for rheumatoid disease.