Berger et al. prospectively compared CT-measured component rotation in 30 TKA patients undergoing revision for isolated patellofemoral complications versus 20 well-functioning controls, asking whether combined femoral and tibial internal malrotation — quantified using the surgical epicondylar axis and tibial tubercle — explains patellofemoral failure in axially aligned knees.
When a TKA patient presents with patellofemoral pain, tracking problems, or patellar instability in a well-fixed, axially aligned knee, get a CT using the surgical epicondylar axis and tibial tubercle as landmarks — combined internal rotation >1° is abnormal, and the magnitude directly predicts whether you're dealing with tilt, subluxation, or an implant headed toward mechanical failure.
This framework tells you not just that revision is needed, but which component(s) to address and what complication to expect if left alone.
Berger et al. prospectively compared CT-measured component rotation in 30 TKA patients undergoing revision for isolated patellofemoral complications versus 20 well-functioning controls, asking whether combined femoral and tibial internal malrotation — quantified using the surgical epicondylar axis and tibial tubercle — explains patellofemoral failure in axially aligned knees.
When a TKA patient presents with patellofemoral pain, tracking problems, or patellar instability in a well-fixed, axially aligned knee, get a CT using the surgical epicondylar axis and tibial tubercle as landmarks — combined internal rotation >1° is abnormal, and the magnitude directly predicts whether you're dealing with tilt, subluxation, or an implant headed toward mechanical failure.
This framework tells you not just that revision is needed, but which component(s) to address and what complication to expect if left alone.