Multiple Choice Questions

DAIR is a valuable option in the treatment of PJI following primary THA. Singly, and when necessary repeated, DAIR can achieve infection eradication in 85% of patients in the hands of arthroplasty surgeons.

DAIRs had a similar ability to eradicate infection, and similar morbidity and complication rates compared with two-stage revisions. Successfully eradicated cases had excellent implant survivorship and very good outcomes. These findings show that DAIR is a particularly useful option in the treatment of hip PJI and should be considered whenever implant stability is not compromised.

One-hit assembled tapers exhibit more contact pressure, plastic strain, and total seating of the head tapers relative to the stem taper compared with three-hit sequence to the same peak load. Subsequent mallet hits leads to inferior taper seating

In 2013, the American Society for Bone and Mineral Research task force developed a revised case definition of atypical femoral fractures. Its definition is that of a fracture located along the femoral diaphysis from just distal to the lesser trochanter to just proximal to the supracondylar flare, with at least four of five major features present. These features are: sustained with minimal or no trauma, the fracture line originates at the lateral cortex and is substantially transverse in its orientation (although it may become oblique as it progresses medially across the femur), complete fractures extend through both cortices and may be associated with a medial spike; incomplete fractures involve only the lateral cortex, non-comminuted or minimally-comminuted fractures and localized periosteal or endosteal thickening of the lateral cortex is present at the fracture site.

Common components of DAIR include open arthrotomy, extensive debridement with synovectomy, thorough irrigation, retention of well-fixed components, and exchange of all modular components. Various adjunctive treatments have been used concomitantly in an attempt to improve local infection control and reduce biofilm, including the use of local antibiotics (e.g., antibiotic beads, sponges, and powder), chemical debridement and lavage with various antiseptic agents (e.g., betadine, chlorhexidine, peroxide, etc), and physical debridement or treatment of implants