Final answer:
The treatment of an osteolytic defect surrounding a screw in a THA depends on the stability of the prosthesis and presence of infection. Stable, asymptomatic cases may require observation and imaging, whereas instability or infection necessitate surgical intervention such as debridement or revision surgery.
Step-by-step explanation:
The correct treatment of an isolated expanding osteolytic defect surrounding a screw in a Total Hip Arthroplasty (THA) often requires a multifaceted approach. Initially, it is essential to evaluate the stability of the prosthesis. If the prosthesis is stable, and there are no signs of infection, measures such as careful observation and serial imaging may be appropriate, especially if the patient is asymptomatic. However, if the prosthesis is unstable or there's evidence of infection, surgical intervention may be necessary. This could involve debridement, revision surgery, or the use of bone grafts or bone graft substitutes to fill the defect and restore skeletal integrity. Patient-specific factors and the size and location of osteolytic changes are important considerations when planning treatment.