This article appeared in Rock and Ice issue 203 (July 2012).
A week ago I injured my left knee while heel hooking on a boulder problem in the gym. There was an audible pop and moderate pain/numbness immediately thereafter. Pain is now pretty localized to the outside of the knee, in the groove between what I think is the hamstring tendon and IT band, just behind the top of the fibula. If I bend my leg slightly and drag it towards me there is sharp pain in this location.
—Climbgunks, via rockandice.com
Though I am reluctant to say something has been missed on the MRI, your history strongly suggests as much. Or at least the MRI hasn’t been read with a particular injury, one that is uncommon in the normal population, in mind. Although this site is viewable on most knee MRIs, it is often overlooked as a source of pain.
The Tibiofibular joint at the knee has two primary ligaments, anterior and posterior. When you rock onto a heel, usually with your knee pointing more out than up, these ligaments are under enormous duress.
One of my patients snapped both of hers, and now the head of the fibula floats around like yesterday’s celebrity. Most often, only one ligament ruptures, and the joint remains quite stable.
I have only seen this injury in climbers, and usually at a rate of one every few months. The history is always the same and almost identical to yours.
A heel rockover is the primary mechanism of injury; heel-toe techniques are especially aggravating post injury, and can take up to several lifetimes
to settle down.
This is a complex area and other structures could be involved. I can’t rule out some damage to the popliteus and its anchors if your foot was pulling in line rather than the rock over described above. Either way, surgery is unlikely and it’s a matter of time and rehab.