A line perpendicular from the lateral epicondyle, should bisect the line drawn between Gerdy's tubercle and the head of the fibula.
Gerdy's tubercle is the attachment site of the iliotibial band.
Gerdy's tubercle is a key surgical landmark
The surgeon uses this landmark when deciding where to position the incision for surgery to the posterolateral corner and the lateral meniscus, and indeed all surgery in the upper lateral tibia, in order to avoid damage to the common peroneal nerve in that area.
"Most surgical approaches to the proximal tibia and distal femur reference Gerdy's tubercle as a critical landmark. Its identification is therefore paramount. Unfortunately, the bony landmark can be skewed by soft tissue swelling, morbid obesity, or disruption from bony injury."
Why the common peroneal nerve should be avoided during surgery
The common peroneal nerve innervates the lower limb, and damage during surgery may lead to a foot drop, as well as alteration of sensation.
For example, where...."arthroscopic meniscal repair is performed, the peroneal nerve can be captured or tethered within the sutures when the inside-out technique is used...."
What is the iliotibial band?
The iliotibial band is an easily-palpated landmark when it comes to identifying Gerdy's tubercle.
"The [iliotibial band] ITB is....a band of dense fibrous connective tissue that passes over the lateral femoral epicondyle and attaches to Gerdy's tubercle on the anterolateral aspect of the tibia. ITB friction syndrome is an overuse injury well recognized as a common cause of lateral knee pain. "
Forum discussions
- Questions for those that have had IT band syndrome - Discussing pain over Gerdy's tubercle from pulling by a tight IT band.