Orthopedic Adult Reconstructive Surgery MCQs & Review | Hip & Knee Arthroplasty Exam Prep

Acetabular erosion

Degenerative arthritis of the ipsilateral knee

Abductor tear

Spinal stenosis

Aseptic loosening Figures A-C show a cementless Austin-Moore hemiarthroplasty with pedestal formation at the distal aspect of the stem with a large radiolucent line in Gruen zones 5 and 6. This, along with her clinical presentation of thigh and knee pain, is most consistent with aseptic loosening. Aseptic loosening is a common reason for revision hip arthroplasty and should be considered in any patient who presents with groin, buttock or thigh pain after a hip replacement. In this situation, ESR and CRP values were within defined limits, making infection highly unlikely. Common reasons for aseptic loosening include poor initial fixation, osteolysis, and mechanical loss of fixation over time. Signs that are suggestive of aseptic loosening include progressive radiolucent lines, change of implant position on sequential radiographs, a positive bone scan, and pedestal formation at the distal aspect of a femoral stem. In this situation, there were no prior radiographs available, but her clinical presentation, pedestal formation, and large radiolucent line suggest motion of the prosthesis within the canal. Portillo et al. reviewed 112 patients undergoing revision surgery after hip, knee, shoulder and elbow arthroplasty. Aseptic loosening was the most common reason for revision. Revisions An 86-year-old man complains of knee pain and swelling 10 years after total knee arthroplasty. On examination, he has no fever, and his knee is neither red nor warm. The clinical appearance of his knee is shown in Figures A and B. An immediate post-operative radiograph taken 10 years ago is shown in Figure C. A current radiograph is shown in Figure D. Knee aspiration reveals 700 WBC/mm3 with 55% neutrophils. What is the most likely diagnosis?