The proximal tibio-fibular joint (PTFJ) is often the younger, less athletic brother of the very common tibio-femoral joint. It just doesn’t get any attention. However, it has received some notice in the literature and seems to be a bigger deal as of late. Authors have several nicknames for the PTFJ, such as the “often-forgotten cause of lateral knee pain” and “4th compartment of the knee”.
Don’t get me wrong, going directly to the PTFJ is not my first stop. However, as I write this, should it? As prevalent as ankle and knee injuries are, why not look in-between? I like to compare the PTFJ to the scapulothoracic articulation with its relationship between the thoracic spine and GHJ. Don’t we look at this quite often while treating the shoulder?
This monograph is not going to delve into the anatomy, biomechanics, etc. of the PTFJ. Most textbooks and even google searches will give you that pertinent information. I will instead give short segments on when (part 1) and how (part 2) I treat it.
Most of the work concerning PTFJ comes from injuries to the ankle, predominantly acute and chronic lateral ankle sprain. I do not see a large number of sprains, but I do address the PTFJ after fractures of the foot/ankle complex. There is a correlation between its mobility and the talocrural/subtalar joint; especially after an injury and altered gait & movement patterns. The fibula can move superiorly with EV & DF moments but if its hypomobile, this can restrict proper mechanics and result in pain. Again, I look directly at the talocrural and subtalar joints first, but this can be the money-maker difference in results.
2. Osteoarthritis of the knee
The signs and symptoms of OA are fairly straightforward that seems to lead me into a straight-forward path to the tibiofemoral joint. Unfortunately, if results aren’t made; then I assume higher grade of OA, lack of HEP adherence and not anything I could have done different. Addressing the PTFJ may get you better results…
3. Sport Injuries
Again, I do not see a large percentage of sports injuries but damage to the posterolateral corner (popliteus, LCL, acuate complex) or “acting” like this instability can actually be more involvement at the PTFJ. I am not the best person to make much of an opinion on this so I would consult with a more versed clinician in this field. However, it is well worth a more local exam at the PTFJ and not relying on fair numbers on clinical testing to the posterolateral corner.
4. Non-mechanical pain
I undoubtedly feel that the manual assessment (not just examination but treatment) can be a large indicator of non-mechanical disorders. Many neoplasms (osteosarcoma, neurofibromas, etc.), pigmented villonodular synovitis, and cysts can be found in this area. If your typical A/P, P/A, IR/ER glides of the tibia on the femur are not making a dent in the symptoms, then I would look at the PTFJ before making unsound assumptions and ask for imaging.
What are your thoughts? How often do you see pain arising from the PTFJ?