There are four stages of posterior tibial tendon dysfunction
. In the first stage the posterior tibial tendon is inflamed but has normal
strength. There is little to no change in the arch of the foot. In stage two the tendon is partially torn or shows degenerative changes and as a result loses strength. There is considerable
flattening of the arch without arthritic changes in the foot. Stage three results when the posterior tibial tendon is torn and not functioning. As a result the arch is completely collapsed with
arthritic changes in the foot. Stage four is identical to stage three except that the ankle joint also becomes arthritic.
Causes of an adult acquired flatfoot may include Neuropathic foot (Charcot foot) secondary to Diabetes mellitus, Leprosy, Profound peripheral neuritis of any cause. Degenerative changes in the ankle,
talonavicular or tarsometatarsal joints, or both, secondary to Inflammatory arthropathy, Osteoarthropathy, Fractures, Acquired flatfoot resulting from loss of the supporting structures of the medial
longitudinal arch. Dysfunction of the tibialis posterior tendon Tear of the spring (calcaneoanvicular) ligament (rare). Tibialis anterior rupture (rare). Painful flatfoot can have other causes, such
as tarsal coalition, but as such a patient will not present with a change in the shape of the foot these are not included here.
The symptoms of PTTD may include pain, swelling, a flattening of the arch, and an inward rolling of the ankle. As the condition progresses, the symptoms will change. For example, when PTTD initially
develops, there is pain on the inside of the foot and ankle (along the course of the tendon). In addition, the area may be red, warm, and swollen. Later, as the arch begins to flatten, there may
still be pain on the inside of the foot and ankle. But at this point, the foot and toes begin to turn outward and the ankle rolls inward. As PTTD becomes more advanced, the arch flattens even more
and the pain often shifts to the outside of the foot, below the ankle. The tendon has deteriorated considerably and arthritis often develops in the foot. In more severe cases, arthritis may also
develop in the ankle.
Perform a structural assessment of the foot and ankle. Check the ankle for alignment and position. When it comes to patients with severe PTTD, the deltoid has failed, causing an instability of the
ankle and possible valgus of the ankle. This is a rare and difficult problem to address. However, if one misses it, it can lead to dire consequences and potential surgical failure. Check the heel
alignment and position of the heel both loaded and during varus/valgus stress. Compare range of motion of the heel to the normal contralateral limb. Check alignment of the midtarsal joint for
collapse and lateral deviation. Noting the level of lateral deviation in comparison to the contralateral limb is critical for surgical planning. Check midfoot alignment of the naviculocuneiform
joints and metatarsocuneiform joints both for sag and hypermobility.
Non surgical Treatment
Nonoperative treatment of stage 1 and 2 acquired adult flatfoot deformity can be successful. General components of the treatment include the use of comfort shoes. Activity modification to avoid
exacerbating activities. Weight loss if indicated. Specific components of treatment that over time can lead to marked improvement in symptoms include a high repetition, low resistance strengthening
program. Appropriate bracing or a medial longitudinal arch support. If the posterior tibial tendon is intact, a series of exercises aimed at strengthening the elongated and dysfunctional tendon
complex can be successful. In stage 2 deformities, this is combined with an ankle brace for a period of 2-3 months until the symptoms resolve. At this point, the patient is transitioned to an
orthotic insert which may help to support the arch. In patients with stage 1 deformity it may be possible to use an arch support immediately.
For those patients with PTTD that have severe deformity or have not improved with conservative treatments, surgery may be necessary to return them to daily activity. Surgery for PTTD may include
repair of the diseased tendon and possible tendon transfer to a nearby healthy tendon, surgery on the surrounding bones or joints to prevent biomechanical abnormalities that may be a contributing
factor or both.