The correlations between dimensions of the normal tendon and tendinopathy changed Achilles tendon in routine magnetic resonance imaging

This comparative study aimed to investigate how tendinopathy-related lesions change correlations in the dimensions of the Achilles tendon. Our experimental group included 74 patients. The mean age was 52.9 ± 10.4 years. The control group included 81 patients with a mean age was 35.2 ± 13.6 years, p < .001. The most significant difference in correlation was the thickness of the tendon and the midportion's width, which was more significant in the tendinopathy (r = .49 vs. r = .01, p < .001). The correlation was positive between width and length of the insertion but negative in normal tendons (r = .21 vs. r = − .23, p < .001). The correlation was between the midportions width in tendinopathy and the tendon's length but negative in the normal tendon (r = .16 vs. r = − .23, p < .001). The average thickness of the midportion in tendinopathy was 11.2 ± 3.3 mm, and 4.9 ± 0.5 mm in the control group, p < .001. The average width of the midportion and insertion was more extensive in the experimental group, 17.2 ± 3.1 mm vs. 14.7 ± 1.8 mm for the midportion and 31.0 ± 3.9 mm vs. 25.7 ± 3.0 mm for insertion, respectively, p < .001. The tendon's average length was longer in tendinopathy (83.5 ± 19.3 mm vs. 61.5 ± 14.4 mm, p < .001). The dimensions correlations in normal Achilles tendon and tendinopathic tendon differ significantly.