The tibial 2.4mm guide pin should be positioned at what measurement relative to Gerdy's tubercle?

The correct answer, which specifies a measurement of 22mm posterior and 10mm distal from Gerdy's tubercle, is based on the anatomical landmarks that are critical for proper placement during surgical procedures involving the tibia, particularly in procedures like anterior cruciate ligament (ACL) reconstructions.

Positioning the tibial guide pin accurately is essential to ensure optimal outcomes in these surgeries. Gerdy's tubercle serves as a reliable bony landmark, and understanding the precise distances relative to it allows surgeons to target the correct location on the tibia for fixing grafts and ensuring proper alignment and stability.

In this case, the 22mm posterior positioning ensures that the pin is placed safely behind the anterior border of the tibial plateau, preventing potential complications with vascular or neurovascular structures. The 10mm distal measurement is crucial for achieving the adequate depth necessary for the fixation device to be effective. Thus, this combination helps to create an appropriate tunnel for grafting while maintaining the integrity and functionality of the knee joint.