The role of joint afferents in sensory processing in osteoarthritic knees.

OBJECTIVE To test the role of joint receptors for proprioception in patients with bilateral knee osteoarthritis (OA) and patients who had undergone unilateral total knee arthroplasty (TKA). METHODS Nine patients were tested bilaterally with a conventional movement detection paradigm that evaluated conscious detection perception and a newly developed hunting paradigm that measured maximal sensory performance (hunting perception). RESULTS For detection perception, patients exhibited a slightly lower threshold on the arthritic side than on their TKA side. For hunting perception, the patients showed threshold values that were an order of magnitude smaller than for the conventional paradigm in both knees. Performance was much better on prosthetic knees than on OA knees. CONCLUSION The joint receptors of OA knees might have an adverse effect on the maximal proprioceptive performance, being important for the normal reflexive knee joint functions. These deficits may be overcome by joint receptor removal during knee replacement.