The fibula is a long narrow bone to the outer side of the tibia (shinbone). At its upper end it articulates with the tibia bone and has ligamentous attachments to the femur. At the lower end it is a major component of the ankle joint.

Popliteus muscle and popliteus tendon
Illustration of the back of the knee to show the relationship of the fibula to other important structures in the knee.


Proximal tibiofibular joint instability

A severe ankle twist may transmit the force right to the top of the fibula, and stretch the ligaments connecting the fibula to the tibia. The fibula may periodically sublux (slip partially out of joint) at the lower side of the knee. High force injuries, such as road traffic accidents, may disrupt the joint to the extent that the top of the fibula can actually rotate outwards during a deep squat, and the peroneal nerve may be irritated and cause pain in this region.


The bones of the knee

Brief introduction to the bony anatomy of the knee, with clear illustrations.

Posterolateral corner

A brief overview of the anatomy in this important part of the knee.

An 'interpretation' of a 2006 medical article outlining the important anatomy of the important posterolateral corner of the knee, and the surgical procedures that are relevant there.



Dislocation of the proximal tibiofibular joint. Milankov M, Kecojević V, Gvozdenović N and Obradović M. Med Pregl. 2013 Sep-Oct;66(9-10):387-91.

Lateral ankle fracture with missed proximal tibiofibular joint instability (Maisonneuve injury).. Hirschmann MT, Mauch C, Mueller C, Mueller W and Friederich NF. Knee Surg Sports Traumatol Arthrosc. 2008 Oct;16(10):952-6. doi: 10.1007/s00167-008-0597-8. Epub 2008 Aug 19.

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