Epiphyseal impaction as a cause of severe osteoarticular pain of lower limbs after renal transplantation

Abstract

A syndrome of severe osteoarticular pain of lower limbs occurring early after renal transplantation (TP) has been recently identified. We describe its prevalence, clinical presentation and outcome. Symptomatic patients have been studied with conventional X-rays, magnetic resonance (MR) imaging, and 99mTechnetium scintigrams of the painful areas. Among 86 patients transplanted over a two-year period, nine (4 men, 5 women; mean age of 40.4 years; range 32 to 59) developed unexplained severe spontaneous osteoarticular pain of lower limbs 19 to 105 (mean 58) days after TP. Pain affected hip(s), knee(s), and/or ankle(s). Clinical examination was usually unremarkable. Favorable outcome was the rule; mean duration of pain was 86 (range 19 to 175) days. Radiographs were abnormal (joint swelling, patchy osteoporosis and/or periosteal reactions) in 41%, MR (epiphyseal fatty marrow replacement by edema and/or hemorrhages) in 83%, and bone scans (one to several epiphyseal foci of increased uptake) in 81% of the symptomatic examined areas. Among joints re-examined 9 to 12 months after resolution of the symptoms, X-rays showed periosteal reactions in 31%, and the bone scans disclosed persistent increased uptake in 53% of the joints, whereas epiphyseal MR abnormalities had completely disappeared in 86%. There was no difference in dialysis duration, post-TP weight gain, evidence of hyperparathyroidism, and steroid and cyclosporine doses between symptomatic and an appropriately selected group of asymptomatic patients. By contrast, serum alkaline phosphatase levels were transiently higher (at the onset of symptoms) in the symptomatic group. Clinical presentation and outcome, imaging findings (mainly MR), and transient elevation in alkaline phosphatase levels sugest a diagnosis of epiphyseal impaction as the basis of this syndrome. Cyclosporine and steroids, both osteopenic agents, might have predisposed to impaction. As their dosage was not higher than in an asymptomatic control group, it is suggested that an additional factor such as excessive physical exercise in the post-TP period may play a role.