The Rear Of A Total Ankle Arthroscopy Improved Anatomical Study Of The Axis Approach And Preliminary Clinical Applications

Objectives: The purpose of this present study is to evaluate the safety and operation of a new modified coaxial portals for posterior ankle arthroscopy. Type: Anatomic study and clinical trial. Methods: 20 anticeptic-frozon ankle specimens were divided into 2 teams equally. The original coaxial portals, the modified coaxial portals and the traditional posterior ankle arthroscopy portals were established with K-wires on the No.1 team; Two levels of modified coaxial portals ,1.5cm proximal to the tip of lateral malleolus and 2.5cm to it, were created on the No.2 team. K-wires were left in place for distance measurement between them and the posterior nerves, tendons and vessels. Mimic ankle arthroscopy technique was performed in 5 fresh ankles using 2.7mm ,30° arthroscopy with the modified coaxial portals . The technique was used on 3 patients (4 ankles) in 2004. Results: Results of the anatomic study show that the average distince was 22.07mm to the small saphenous. 5.39mm to Flexor hallucis longus , 6.27mm to the tibial nerve in modified coaxial portals and 8.54mm to the small saphenous , 3.62mm to Flexor hallucis longus , 4.40mm to the tibial nerve in the original one. Only the difference of the average distance to the tibial nerve in the No.2 team has statistic significance. Statistic results of the anatomic study show that the distinces between the modified coaxial portals and the posterior nerves, tendons and vessels are the farthest one among several portals as mentioned above. Flexor hallucis longus and Flexor digitorum tendon were identified as the inner-safety landmarks. Neither penetrate nor contact of nerve or vessel was observed and no detectable complications at an average 5-month follow-up. Conclusion: Compared with original ankle posterior portals, our new modified coaxial portals may be superior safety , easier operation and reproducible.