Headmaster collar restricts rheumatoid atlantoaxial subluxation

Study Design. A radiographic study of the effect of a modern orthotic devic e in the treatment of rheumatoid atlantoxial subluxation. Objective. To study the ability of a new open-type collar to restrict atlan toaxial subluxation. Summary of Background Data. Atlantoaxial subluxation is common in rheumatoi d arthritis, and thus, the development of conservative treatments is import ant. It has been shown that a custom-made stiff collar significantly restri cts atlantoaxial subluxation in approximately half of patients with unstabl e atlantoxial subluxation. Methods. In 30 successive patients with rheumatoid atlantoaxial subluxation , lateral view radiographs were taken in flexion, extension, and neutral po sitions without a collar and in flexion with the Headmaster collar. Results. The mean atlantoaxial distance during flexion was 7.1 +/- 1.8 mm a nd during extension was 1.0 +/- 1.0 mm, and the mean instability was 6.1 +/ - 2.3 mm. In the 20 cases with the greatest stabilizing effect, the mean at lantoaxial distance during flexion with a collar was 1.1 +/- 1.3 mm, wherea s in 10 patients with lesser effect it was 6.7 +/- 2.5 mm (P < 0.0001). The lesser stabilizing effect was associated with the presence of atlantoaxial subluxation in the neutral position. Conclusion. The Headmaster collar is an effective and useful tool in the co nservative treatment of simple unstable atlantoxial subluxation, but and or dinary custom-made stiff collar is still often needed. These two collars ar e complementary, and their selection and use must be determined individuall y.