[Experimental study about the dorsal approach to arthroscopic lateral release in hallux valgus surgery]

To study the availability and method of the dorsal approach to arthroscopic lateral release in hallux valgus (HAV) surgery.

Ten fresh foot specimens with ankle preserved were included. Lateral capsule and the oblique head of hallucis adductus muscle were released using blade under arthroscopic visualization. Inspection was made for the relationship of the dorsal portals and the surrounding nerves, vessels and tendons. The ranges of release were also recorded. Five cases underwent the dorsal approach to arthroscopic lateral release in hallux valgus surgery. All patients were female, and the average age was 30 years old. The average hallux valgus angle was 30 degrees.

The proximal portal was in close proximity to the extensor hallucis brevis tendon at a distance of 0 - 3 mm (average 1.5 mm) and was at a distance of 1 - 4 mm to the extensor hallucis longus tendon (average 2.4 mm). The distal portal was in close proximity to the first dorsal digital artery and nerve which were vulnerable to injury due to the short distance of 1 - 3 mm (average 1.4 mm). Among the 6 normal feet, metatarsal sesamoid ligament (MSL) was totally released in 1 specimens, and was partially released (70%) in 1 specimen, while in the other 4 HAV feet, 2 specimens had MSL totally released, 1 specimen partially released (50%). The 5 patients were all followed up with the average of 9 months. And the angle of hallux valgus was improved to 7 degrees (range from 4 degrees - 9 degrees).

Dorsal approach to do arthroscopic lateral release in HAV is available. The advantages are small incisions, clear arthroscopic visualization, higher flexibility to release the lateral structures, less possibility of avascular necrosis of the metatarsal head as a result of no vessel injury.