The JBJS Quiz of the Month is a collection of 10 relevant questions from each orthopaedic subspecialty. The questions are drawn from JBJS Clinical Classroom, which houses over 4,500 questions and 3,100 learning resources. Take the Quiz to see how you score against your peers!

NOTE: This quiz does not earn users CME credits. The questions must be answered within Clinical Classroom to earn CME credits.

A 66-year-old male patient who underwent total knee arthroplasty (TKA) 19 months ago presents with persistent right knee pain and swelling. The patient reports difficulty ascending and descending stairs as well as rising out of a chair. He has undergone several sterile aspirations of the knee. On examination, the patient has substantial anterior-posterior laxity of the knee at 90° with the affected leg over the edge of the examination table. Coronal stability is 1 mm at full extension and 2 mm at 30° and 60° of knee flexion. Range of motion is from 0° to 97° of flexion. You recommend revision TKA. At the time of surgery, which of the following is most critical to the success of the revision procedure?
    • Using the subvastus approach to the knee
    • The operative approach to the knee should not impact knee joint stability. In revision surgery, generally an extensile approach should be selected.
    • Restoring the joint line and posterior condylar offset
    • This patient has flexion instability of the knee following TKA. Improving posterior condylar offset and joint-line restoration has the biggest impact in improving knee stability following revision TKA.
    • Upsizing the polyethylene
    • Increasing polyethylene thickness alone has been shown to be unreliable in revision TKA for instability.
    • Ensuring internal rotation of the tibial component
    • Internal rotation of the tibial component has been shown to be the cause of residual pain following primary TKA.