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.
Peer-reviewed paperQuote from peer-reviewed paper:
"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."
Citation: Donegan DJ, Seigerman DA, Yoon RS, Liporace FA. Gerdy's tubercle: the lighthouse to the knee. J Orthop Trauma. 2015 Feb;29(2):e51-3. doi: 10.1097/BOT.0000000000000196. PMID: 25050746.
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.
Peer-reviewed paperQuote from peer-reviewed paper:
[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...."
Citation: Van den Bergh FR, Vanhoenacker FM, De Smet E, Huysse W, Verstraete KL. Peroneal nerve: Normal anatomy and pathologic findings on routine MRI of the knee. Insights Imaging. 2013 Jun;4(3):287-99. doi: 10.1007/s13244-013-0255-7. Epub 2013 May 25. PMID: 23709403; PMCID: PMC3675257.
What is the iliotibial band?
The iliotibial band is an easily-palpated landmark when it comes to identifying Gerdy's tubercle.
Peer-reviewed paperQuote from peer-reviewed paper:
"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. "
Citation: Fairclough J, Hayashi K, Toumi H, Lyons K, Bydder G, Phillips N, Best TM, Benjamin M. The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome. J Anat. 2006 Mar;208(3):309-16. doi: 10.1111/j.1469-7580.2006.00531.x. PMID: 16533314; PMCID: PMC2100245.
Forum discussions
- Questions for those that have had IT band syndrome
Discussing pain over Gerdy's tubercle from pulling by a tight IT band.