Fig 2.

Arthroscopic visualization before and after percutaneous medial collateral ligament (MCL) trephination. Side-by-side arthroscopic images of the left knee, with the patient in the supine position, viewed from the anterolateral portal using a 30° arthroscope. The knee is flexed to approximately 90° in both images. (A) Pretrephination: Prior to MCL release, the medial compartment provides minimal room for maneuverability of instruments and assessment of the medial meniscus posterior root. The medial femoral condyle (A) and medial tibial plateau (B) crowd the visual field, limiting posterior access. (B) Post-trephination: Following percutaneous release of the medial collateral ligament, visualization of the posteromedial compartment is significantly improved. The medial femoral condyle (A), medial tibial plateau (B), and posterior root of the medial meniscus (C) are clearly visible, with an estimated increase in medial joint space clearance of ∼2-4 mm. This expanded space enhances both arthroscopic visualization and safe passage of surgical instruments during posterior root repair.