Proprioception after total knee arthroplasty: a comparison with clinical outcome

We determined proprioception in replaced and unreplaced arthrotic knees by measuring threshold levels for the perception of passive knee motion. In addition, results of these proprioception measurements were compared with the clinical outcomes in patients with a total knee arthroplasty. Threshold detection levels were significantly higher in the replaced than in the unreplaced knees. Moreover, detection-failure rates were significantly higher in the replaced knees as well. In contrast to this diminished movement sense in the replaced knees, clinical examination of these knees showed good or excellent outcome in all cases. A correlation between the clinical outcome and the ability to perceive passive motion in either patient group could not be found. We hypothesize that our findings may be due to the operative removal of intraarticular receptor-rich tissue that is affected by arthrosis. This would not only contribute to marked clinical improvements but also to a significant decrease in proprioception.