Torsion of the neck and adduction of the head of the talus in normal and congenital flexible flat foot

Abstract

Summary. The influence of neck torsion and adduction of the head of the talus (T) on the mechanogenesis of congenital flexible flatfoot (CFF) remains as unsufficiently studied issue. Aim. To examine the torsion of the neck and adduction of the head of the T in normal conditions and CFF. Material and methods. The study was performed on CT-scans of 36 feet of 20 patients: 17 feet (6 men, 3 women; age 26,9 ± 5 years) met the criteria of CFF, 19 feet (5 men, 6 women; age 31,4 ± 3,6 years) were used as con- trol. The neck torsion angle (NTA), the horizontal angle between the body and the head (body-head angle – BHA) were calculated. In the patients of the experimental group the angle of uncoverage of the head of the T (talo-navicular uncovrage angle – TNUA) was measured on antero-posterior weight-bearing X-ray. Mean comparisons and cor- relations were calculated using appropriate tests at a significance level 0,05. Results. It was established that there was no significant difference between the averages charac- terizing the NTA in the norm [45,7 ± 1,4; CI 95 % (43; 48,4)] and in patients with CFF [47,7 ± 1; CI 95 % (45,8; 49,6)] (p = 0,25), instead BHA in the norm [14,7 ± 1,2; CI 95 % (12,3; 17,1)] was significantly different from that in patients with CFF [18,8 ± 1,3; CI 95 % (16,3; 21,3)] (p = 0,02). A relationship of medium strength (R = 0,5 at p = 0,05) was established between BHA and TNUA. Conclusion. A correlation of medium strength (R = 0,5) between BHA and TNUA may indicate the influence of the medial deviation of the head of the T on the instability of the peritalar zone.