Appropriate Area for Operative Procedures Near Tibialis Anterior Tendon Insertion: A Cadaveric Study

The tibialis anterior tendon has its insertion sites on both the medial and plantar surfaces of the medial cuneiform and the base of the first metatarsal. Operative procedures near those areas, especially at the first metatarsocuneiform joint, may disturb tendon insertions and cause irritation or functional impairment of the tendon.

Tibialis anterior tendons and their insertion sites were dissected and examined from 46 cadaveric feet (19 female and 27 male cadavers, aged between 33 and 86 years, with a mean of 68.5 ± 14.3 years). The greatest lengths and widths of the tendon attachments on the bony surface of the medial cuneiform and base of the first metatarsal, on both the medial and plantar surfaces, were measured and analyzed. The measurement reliability was evaluated by using the intraclass correlation coefficient.

Most of the tibialis anterior tendon insertions were found to be longer at the medial cuneiform than at the base of the first metatarsal (mean, 8.3 and 5.4 mm; P < .001), but the widths were almost similar (mean, 11.0 and 10.4 mm; P = .079). When focusing on each bone, the widths of the tendon attachments on the medial and plantar surfaces of the medial cuneiform were equivalent (mean, 5.4 and 5.6 mm; P = .584). At the base of the first metatarsal, the tendon attachment on the plantar surface was found to be wider than on the medial surface (mean, 7.0 and 3.4 mm; P < .001).

The widths of the tibialis anterior tendon insertions on the medial and plantar surfaces of the medial cuneiform were equal, as were the total widths of insertions on the medial cuneiform and on the base of the first metatarsal. However, the width of insertions on the medial surface of the first metatarsal was significantly smaller than on the plantar surface, and the total length of insertions at the medial cuneiform was longer than at the first metatarsal.

This study provides information about characteristics of the tibialis anterior tendon insertions, particularly details of the dimensions on each surface of the bones. This knowledge enables surgeons to minimize the risk of irritation or tendon injuries during operations near the base of the first metatarsal and medial cuneiform area.