anatomical sources of pain in the knee joint osteoarthritis

ABSTRACT

To find the anatomical sources of pain in the knee joint osteoarthritis. Patients 16 patients who had stage II or III of the tibiofemoral joint osteoarthritis were studied consecutively in a one year period. Method: The knee joint tissues were stimulated by different stimuli [cutting, stretching, pressing, pinching, piercing, cauterization, twisting, hitting and injection] through a plane by plane local anesthesia. The awake patients were asked about painful sensation and whether this pain resembled their osteoarthritis pains. 9 patients were women [58%] and 7 were men [42%]. The mean age for women was 61 and for men was 64 years. The mean weight of the patients was 71 kg [71.5 for women and 69.4 for men]. 50% of the tested joints were right knees and 50% were left ones. 12 knee joints were in stage III of tibiofemoral joint osteoarthritis and 4 were in stage III. Subcutaneous adipose tissue pains had no significant relation to osteoarthritis pains. Pressing on the knee joint capsule produced a pain similar to the osteoarthritis pains [p<0.02]. Other stimuli had no significant relation to osteoarthritic pains. Synovial membrane was resistant to painful stimuli and no relation was found with osteoarthritis pains. Joint cartilage was rather insensitive to painful stimuli and no relation was found with osteoarthritic pains. Pressing of the subchondral bone could produce 25% of pains similar to osteoarthritis but this relation was not significant. Other stimuli had no relation to osteoarthritis pains. Metaphysis was very sensitive to normal saline injection [p<0.01] and the pain was similar to osteoarthritis pains. The joint capsule and metaphysial bone were sensitive to pressing and injection respectively and experienced pains similar to osteoarthritis pains. So for the treatment of the knee joint osteoarthritic pains, these two sources of pain should be regarded as responsible ones