AB1463-HPR Is there any difference in joint position sense among different knee angles in patients with knee osteoarthritis?
Authors: M Eymir, B. Ünver, V. Karatosun
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> The joint related structures such as joint capsule, menisci, ligaments, muscles, skin provide the sensory input for the knee proprioception. Individuals with knee osteoarthritis (OA) have poor proprioceptive sense when compared with the same ages healthy individuals. Due to OA, the joint structures such as menisci, ligaments, and joint capsule rapidly undergo degeneration, and the deficiency of the knee proprioception progresses. Daily activities such as stair climbing, rise from a chair, walking require different knee joint angles. Therefore, the evaluation of the knee position sense at different joint angles is necessary for a better understanding of the knee proprioceptive sense deficit and for planning rehabilitation program in patients with knee OA. <h3>Objectives</h3> The purpose of this study was to analyse the knee joint position sense in different knee joint angles and to compare the results. <h3>Methods</h3> The study group consisted of 80 patients (62 female/18 male, 124 knees), with unilateral or bilateral knee OA and with a mean age 65.5±9.1 years were included in the study. Patients were evaluated regarding knee proprioception in knee joint angle 30°, 60° and 75°. The starting position was in knee joint angle 90° flexion, and the target angles was attempted to replicate using active knee extension movements. Patients performed active joint angle replication test in sitting position at a standard back supported chair. The average of the 3 repetitions of active joint repositioning test was recorded position sense score. The angular displacements from the target angles (in knee joint angle 30°, 60°, 75°) at the end of the active reproduction tests were recorded as position sense deficit scores. <h3>Results</h3> When the patients' knee position sense deficit at different joint angles (in knee joint angle 30°, 60° and 75°) were compared, there were statistically differences between at joint angle 75° and 60° (p=0.002), and also there were statistically differences between at joint angle 75° and 30° (p=0.001). However, there were not statistically differences between the patients' knee position sense deficit at joint angle 30° and 60° (p&gt;0.05). <h3>Conclusions</h3> According to our results, the patients with knee OA have better proprioceptive acuity at knee joint angle 30°, 60° than at knee joint angle 75°. Specifically, the detection of active knee movement occurred with lower target angle displacement at a starting knee angle close to terminal extension (30°) than at knee angles closer to midrange (75°). These results can be reasonably speculated that proprioceptive input arose primarily from hamstring muscle stretching, posterior capsule tautness, and possibly ligament strain. It could be argued that the observation of the greater motor responses at decreased angles likely have been facilitated from enhanced sensitivity of these sensory terminals. Also, the results of this study may provide guidance for future proprioceptive sensory evaluations and provide guidance for planning rehabilitation programs in patient with knee OA. <h3>Disclosure of Interest</h3> None declared