This work was carried out to assess the frequency of frank
rupture of the tibialis posterior tendon (
TPT) in RA and to determine if other pathology in the tendon can be correlated with
foot deformity. Clinical, radiographic and ultrasonographic signs of
TPT pathology were assessed bilaterally in 28 patients with RA and hindfoot involvement. The degree of hindfoot
pain, the single-heel-rise test and the tibiocalcaneal angle were assessed clinically. The talometatarsal angle was measured on lateral weight-bearing radiographs. Tendon continuity and thickness were noted on sonography, both in the study group and in a control group of 14 patients. The
TPT was significantly thinner in those rheumatoid patients with an abnormal single-heel-rise test when compared to those patients with a normal test (P < 0.001) and to the control group (P < 0.001). The mean thickness in patients with an abnormal test was 1.6 mm, in patients with a normal test it was 2.3 mm and in the controls it was 1.9 mm. In the rheumatoid group thinning of the tendon was significantly correlated (r = -0.33, P < 0.05) with heel valgus as assessed by the tibiocalcaneal angle. It was also significantly correlated (r = 0.31, P < 0.05) with
pes planus as assessed by the talometatarsal angle. Only one case of frank
rupture of the
TPT was identified. There were also significant correlations between
TPT thickness and patient age, disease duration and
steroid therapy, such that tendon attenuation was associated with increasing age, longer disease and
steroid usage. There was no association between
TPT thickness and the degree of hindfoot
pain.(ABSTRACT TRUNCATED AT 250 WORDS)