British researchers collecting and reviewing nationwide data on hip and knee replacements reported that one in 75 patients requires a revision of their joint replacement after 3 years. Although this compares favorably with the rest of the world, the study reinforces concerns about the new surgical techniques of hip resurfacing and unicondylar knee replacement, according to a press release. Findings of the study were published this week in PLoS Medicine.

A multicenter study on patient function after having femoral neck fractures fixed with cancellous screws found that femoral neck shortening as well as varus collapse are common. "Femoral neck shortening occurred in two out of three fractures regardless of whether they were displaced or nondisplaced, and it had a clearly negative impact on functional outcome," said Michael P. Zlowodzki, MD during the American Academy of Orthopaedic Surgeons 75th Annual Meeting, where he presented the results of a large multinational study

Six years after FDA approval of the first bone growth factor, a bone morphogenetic protein, researchers and clinicians still seek a better understanding of these powerful substances, their uses and limitations. Of all the bone growth factors studied, bone morphogenetic proteins (BMP) expressed during bone healing have been found most effective for initiating bone growth in clinical situations such as spine fusion and fracture healing. "I think growth-factor-based strategies are important for bone formation, especially in difficult situations," Scott D. Boden, MD, said. During a presentation he made to attendees at the American Academy of Orthopaedic Surgeons and Orthopaedic Research Society annual meetings, Boden discussed key issues that still require work before further clinical optimization of BMPs occurs. He said, "The issues are dose and carrier optimization, controlling local side effects and deciding when we need things of this potency."

Surgeons have a host of biologic strategies to restore bone. At the American Academy of Orthopaedic Surgeons 75th Annual Meeting, J. Tracy Watson, MD, discussed current and emerging technologies used to re-grow bone in challenging fracture cases. "I think that the future is happening now," Watson said during his presentation. "We are using every available technology alone and in combination to maximize our union rates. For smaller bone defects composite graft therapies utilize cellular bone marrow aspirates, concentrating the colony forming units. These cellular components are then combined with BMP cocktails, and conductive substrates which offer the surgeon a powerful bone graft tool. Other restorative techniques utilize rapid bone transport techniques as well as biomaterial segmental bone replacement and reconstruction of massive defects."