Tendinous laxity and Jaccoud's syndrome in patients with systemic lupus erythematosus. Possible role of secondary hyperparathyroidism.

Fourteen of 52 unselected patients with systemic lupus erythematosus (SLE) (27%) had ligamentous derangement demonstrated by either Jaccoud's syndrome and/or patellar tendon elongation. Three cases had only Jaccoud's syndrome, 4 isolated patellar tendinous laxity, while the remaining 7 presented both findings. Jaccoud's syndrome and/or tendinous laxity were not associated to an increased frequency of arthritis, corticosteroid therapy or a longer disease duration, but significantly associated with increased serum PTH levels secondary to chronic renal failure. Hyperparathyroidism secondary to chronic renal failure should, therefore, be considered a potential factor contributing to the development of Jaccoud's syndrome and/or tendinous laxity in patients with SLE.