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Posterior Tibial Tendonitis

Posterior tibial tendonitis can occur in an older person, male or female, probably more commonly female posterior tibial tendonitis, tendinitis. She may tell you, "I have had this ankle sprain on the inside, it’s just not getting better." "It hurts, it swells, they told me it’s arthritis, they told me it’s a bad sprain." Sometimes in severe cases, they complain of lateral foot pain because as this foot turns out and continues to turn out, the calcaneus bumps against the fibula or pinches the peroneal tendons between the calcaneus and the fibula and they start to have pain over here.

On examination, when you have them do a heel rise test, which for this gentleman, ask him to go up on his toes, when you do that, your posterior tendon should fire and your heel should drift to the midline, it should invert. Well, when your posterior tendon doesn’t work, your heel stays out laterally and is more valgus position. Another physical sign to look on physical exam is the too many toe sign, and this slide really isn’t that great for it, but the idea of being that if your arch is collapsed and your forefoot is abducted to the forefoot is drifting away from the midline that like slide I showed you in the beginning, the lady with the very flat foot, you are going to see not only the fifth toe, but the fourth toe and maybe even in severe cases, the third toe when you compare that to the other side and you are just seeing the fifth toe there, so that’s the too many toe sign, or more toe sign as some people describe it. Why has this happened? True frank rupture of the posterior tibial tendon is rare, it happens but it’s rare. More of the mechanism, you can sort of think of it as a fraying row, the tendon is stretched, it has longitudinal splits that causes local inflammation in the tendon.

For a variety of reasons, the posterior tibial tendon is being overworked to try and lock that transverse tarsal joint to make a rigid lever for push-off, and as it gets attenuated. Some of the secondary things, the Achilles tendon becomes contracted. Here is a slide again of the lady I showed you earlier, she has no arch, so the arch has drifted down, her calcaneus is relatively sort of drifted up and shortened this distance here, and as this Achilles tendon becomes contracted.

In severe cases, people develop arthritis on the dorsal aspects of these joints. Why, they are gapping down here and they are unloading here, they are compressing and tilting up here, and that can cause focal wear of the joint surface. Also, these people can get arthritis in their ankle and deformity in their ankle.

So we get rid of that inflammatory process, get rid of the pain, and then we can try to switch them over to shoes, orthotics or even a brace in some severe cases, so they don’t have to be in the cast forever. I also again combine that with physical therapy. As I said before, posterior tibial tendonism is elongated, so we try to do some physical therapy to maximize what muscle function is left to help lock that transverse tarsal joint to make the foot a rigid lever. I need to stretch out the everters of the foot, the peroneus brevis which everts the foot and contributes to that abduction, that can get contracted if there has been a long-standing pes planovalgus. I need to have then stretch that out, work that out so they don’t have that as a deforming force to the axis of balance. I need to stretch their gastrocnemius and their Achilles tendon, they probably have a contracture over time as the foot.

When I look at someone who presents to me with a foot complaint, I try to break it up into what the primary pathology is, and what are the secondary manifestations that they are coming to me to complain about? The foot is a complex weight bearing surface. There re 28 bones and nearly 60 articulating surfaces, so there are a lot of inter-relationships going on between the different segments of the foot, the hind foot, mid foot and forefoot, and problems in one region can have manifestations elsewhere. So it is very important to recognize what the root cause of the problem is, as well as identifying all the secondary manifestations. So when I think of the problems, I start to look at the structural malalignments.

There are the seven tarsal bones in the hindfoot region, we have that defined as the calcaneus, and the talus, that separates the hindfoot from the midfoot through the transverse tarsal joint. The remaining five tarsal bones are the middle, medial and lateral cuneiform, the cuboid bone, and the navicular. Then you enter into the forefoot which has the five metatarsal bones and the 14 phalanges. As you know, in the hallux, there are only two phalanges, whereas in the lesser toes, there are three, and then the two sesamoids that are under the first metatarsal head. Ligaments are important for static stabilization of the arch of the foot, both it’s longitudinal arch and the transverse arch. The spring ligament, if you look on the slide here, again we are looking up under the foot, here is the calcaneus, here are the metatarsals down here, the spring ligament is sort of a sling that runs from the calcaneus to the navicular, a sling for the arch and the medial aspect of the foot. The long plantar ligament is an important ligament.

Another concept that I use frequently when I am looking at foot problems, is that the foot should have an axis of balance. That axis of balance runs along the sagittal plane. It goes from the center of the calcaneus, to the center of the midfoot, and runs between the second and third metatarsals in the forefoot. Weight bearing forces are balanced across that access medially and laterally, in fact, minimal muscle activity is required for quiet standing. The muscle forces, or the dynamic forces during the phases of gait are also balanced across this access for dorsiflexion, plantar flexion, but mostly for inversion and eversion of the foot to stabilize and square the foot up to the ground surface. Now that axis of balance is dynamic, you can lock and unlock the arch.