CALCANEAL INVOLVEMENT IN REACTIVE ARTHRIT IS - CLINICAL ASPECTS - CONTRIBUTION OF ROENTGENOGRAPHY AND RADIONUCLIDE BONE SCANNING TO THE DIAGNOSIS - A REVIEW OF 102 CASES

Among 102 patients with definite reactive arthritis (group I), with a mean age of 26.4 years, 47 had heel pain, which was inaugural in eight cases, bilateral in 21, plantar in 35, and posterior and/or bipolar i n 12 (retrocalcaneal bursitis, n = 2), Roentgenograms of the calcanei (96 cases) were abnormal in 42 cases (including 35 with heel pain), sh owing simple erosion (n = 15), erosion with reconstruction (n = 14), o r only reconstruction (n = 13, including seven without heel pain); roe ntgenograms thus detected calcaneal involvement in 7.3 % of cases (7/9 6). In contrast, 20 controls with heel pain due to pes cavus had norma l roentgenograms (p<0.01). Calcaneal hyperactivity was seen on bone sc ans in 45 of the 63 patients who had this investigation, versus none o f the 20 pes cavus controls and none of 20 controls with lumbar disk d isease (p<0.01 for both comparisons). Among the patients with calcanea l hyperactivity, 17 did not have heel pain and 12 did not have roentge nographic changes; since nine of the 12 latter patients did not have h eel pain, the bone scan detected calcaneal involvement in 14.3 % of ca ses (9/63). Heel pain resolved in every case, after a mean interval of 4.4 months (range, one to 13 months) Among 20 patients with probable reactive arthritis (group II) who had roentgenograms of the calcanei, three had calcaneal changes; these changes established the diagnosis i n one patient who did not have heel pain. Of the 13 group II patients who had a radio-nuclide bone scan, seven had calcaneal hyperactivity; of these seven, three had no heel pain or roentgenographic calcaneal c hanges and were thus given a diagnosis of-reactive arthritis based on the bone scan findings. In patients without heel pain, roentgenograms, or, if these are normal, radionuclide bone scanning can establish the diagnosis of reactive arthritis in a small proportion of cases.