Bone destruction patterns of the rheumatoid elbow: a radiographic assessment of 148 elbows at 15 years.
A cohort of 74 patients with rheumatoid arthritis (RA) was followed prospectively for 15 years. At the end of the study, 148 elbows were radiographed with standard methods. The bone destruction of the humerus was measured from the anteroposterior (AP) radiograph as the bone attrition of the trochlea (TM) and the capitellum (CM). The bone destruction of the ulna was measured from the AP radiograph as the width (WO) and from the lateral radiograph as the thickness (TO) of the olecranon. Moreover, elbow joint destruction was graded by the Larsen system on a scale of 0 to 5. The relation of bone destruction to Larsen grade of the elbows was examined. The mean TM of the nonaffected (Larsen grades 0 to 1, n = 73) joints was 17.5 mm (SD, 2.1 mm; range, 10-22 mm), whereas the mean of Larsen grade 3 to 5 joints (n = 26) was 11.5 mm (SD, 5.2 mm). The mean CM of the nonaffected joints was 19.6 mm (SD, 2.6 mm; range, 15-25 mm), and the corresponding mean of Larsen grade 3 to 5 joints 15.5 mm (SD, 4.5 mm). The mean TO of the nonaffected joints was 18.9 mm (SD, 1.5 mm; range, 17-23 mm), and the mean of Larsen grade 3 to 5 joints was 13.9 mm (SD, 4.1 mm). The mean WO of the nonaffected joints was 23.3 (SD, 2.4 mm; range, 18-28 mm), and the mean of Larsen grade 3 to 5 joints was 22.4 mm (SD, 6.2 mm). Spearman correlation coefficients between TM, CM, and TO and Larsen grade of the joint were -0.45 (95% CI, -0.31 to -0.57), -0.38 (95% CI, -0.23 to -0.51), and -0.46 (95% CI, -0.31 to -0.57), respectively. Bone destruction in both the humerus and the olecranon appears to be a late consequence of rheumatoid elbow involvement. Bone loss is always present in the situation of rheumatoid elbow replacement, and it is most remarkable in Larsen grade 5 joints; the risk of preoperative and intraoperative complications due to bone destruction is significantly increased in this group.