The impact of hemiparalysis on the expression of osteoarthritis

Objective. Primary generalized osteoarthritis (OA), the most prevalent join t disease, is usually symmetric. Sporadic case reports mention decreased OA manifestations in limbs in which there are neurologic deficits, but no sys tematic research has been published. The aim of the present study was to ex amine these observations in a planned and controlled survey in a group of p atients with OA, Methods. Seventy-five geriatric patients with a history of stroke and hemip aralysis were studied clinically and radiographically (hand radiographs; gr aded according to a modified Altman method) for the presence and the degree of OA in the hands. Detailed clinical and radiologic scores were calculate d for each hand. Demographic, occupational, and neurologic data were collec ted. Patients with other joint or neurologic conditions were excluded. A gr oup of 55 elderly patients without stroke were similarly studied (controls) , Scores in the paralyzed hand were compared with those in the nonparalyzed hand in the stroke patients and subgroups (by Student's paired t-test and Wilcoxon test). Scores in the dominant hands were compared with those in th e nondominant hands in stroke patients and control subjects (by Student's p aired t-test and Mann-Whitney test). Correlation between the degree of neur ologic damage and OA asymmetry (Pearson's correlation coefficient) was also sought. Results. Paralyzed hands showed significantly fewer OA changes than nonpara lyzed hands, both clinically and radiologically. This trend, accentuated in patients with more severe paralysis, disappeared in those with mild residu al paresis, Asymmetry of OA was more pronounced in patients with flaccid, c ompared with spastic, paralysis. The degree of paralysis and loss of muscle strength correlated with the degree of OA asymmetry. Women had significant ly higher OA scores than men. In the control group, dominant hands had high er OA scores, but this finding was concealed among hemiparalyzed patients, Lifetime gross occupational load and present grip strength did not correlat e with the degree of OA. Conclusion. In elderly patients, hemiparalysis reduces ipsilateral hand exp ression of OA, while OA is accentuated (or increased) in the dominant hand of patients without paralysis. This first systematic study confirms the fin dings of previous case reports and lends support to the role of biomechanic al factors in the development of OA.