Y sign: new landmark for anteromedial portal placement in knee arthroscopy.

Purpose: During arthroscopy training process, determination of anteromedial portal is more difficult in contrast with anterolateral portal and frequently results in suboptimal position, and longer operating times. The aim of our study was to identify an anatomical landmark which could facilitate anteromedial portal placement.

Methods: The relationship of the cutaneous veins at the anteromedial side of the knee was analysed regarding the optimally placed anteromedial portal and anatomical landmarks of the anteromedial part of the knee in 70 patients undergoing knee arthroscopy. The study was designed as case series.

Results: In 70% of the patients, the joining of the cutaneous veins was seen after transillumination resembling Y letter. In the remaining 30% of patients, a solitary vein with a curve which corresponds to the joining point was observed. The curve and the joining was located adjacent to optimally placed anteromedial portal measured 2 cm ± 0.3 from the medial patellar tendon border, and 1.1 cm ± 0.1 from the palpable edge of the medial tibial plateau.

Conclusions: The "Y sign" can assist knee arthroscopy trainees in anteromedial portal placement, with the resulting avoidance of multiple puncturing of the skin with the needle, shorter operating room times to find the optimal portal placement, and potential reduction of damage to intraarticular structures.