Are we Measuring Knee Proprioception Correctly? A Case-Control Study of Joint Reposition Sense and Reflex Latencies for Measuring Proprioception in Knee Hemophilic Arthropathy.

Background and Aims: Knee proprioception deficits have been found in several types of knee injuries using different measurement techniques. In some cases, such as hemophilic arthropathy, such deficits have been largely inferred from the results of gait and postural stability tests. Hemophilic arthropathy is supposed to produce balance and neuromuscular control impairments associated to knee proprioception deficits. However, there is a lack of studies focused specifically on the measurement of joint proprioception in this group of patients. The aim of this case-control study was to analyze local knee proprioception through joint reposition sense error and reflex muscle latencies in subjects with different degrees of hemophilic arthropathy. Methods: 11 healthy subjects and 13 patients with hemophilic arthropathy (7 with a lower grade and 6 with a higher grade arthropathy) participated in the study. Knee proprioceptive acuity was measured by means of: (1) the repositioning error between two repetitions of complete extension and mid-flexed knee positions, and (2) the onset latencies of rectus and biceps femoris reflex activations during sudden knee loading. This study has been presented by the STROBE guidelines. Results: No statistical differences between groups were found either in joint repositioning error or onset latencies of reflex activation. The present study shows that knee proprioception could be preserved on patients with hemophilic arthropathy. It is possible that past measurements of knee proprioceptive acuity in these and other groups of patients have not been specific enough. Conclusion: Our results suggest the necessity of a reevaluation of the association of some types of knee injuries with knee proprioceptive alterations.