Cath Lab Digest

   Stage III AAF. The Stage III transition is characterized and easily differentiated from I and II by rigidity of the rearfoot. Forced weightbearing manipulation of the rearfoot into a more neutral position is not possible. Radiographs usually demonstrate moderate to severe arthritic changes at the posterior facet of the subtalar joint and degeneration of subchondral bone at the talonavicular joint. Of course, the simple heel raise, lag test, first metatarsal rise test and the Hubsher maneuver are all failures.

   Stage IV AAF. This stage is classified as the most dramatic deformity and is resistant to any treatment options other than surgical fusions. The hallmark of this deformity is the severe valgus deformity of the talocrural joint, degenerative joint disease of the rearfoot joints and, in dramatic cases, fractures of the fibular malleolus secondary to the huge lever of the lateral deforming forces.

   We know from the literature that AAF is not simply pathology of the tibialis posterior. There are assessment tools one can use to classify this disorder and proper staging of the disorder is necessary to facilitate appropriate therapy.

Can Conservative Therapies Have An Impact?

Goldner suggested tendon repair and Johnson described synovectomies for the early stages of AAF, transfers for the middle stages of AAF and arthrodesis for the later stages.^7,8 Few clinicians are satisfied with the surgical approach to this pathology and deformity.

   Non-surgical treatments of AAF do not correct the pathology but do seem to slow the progression, reduce symptoms and reverse disability. The course of treatment must, by all accounts, be coordinated with the staging of the deformity. Most authors recommend conservative care for the initial management of symptoms. The Richie update of the Johnson and Strom classification utilizes the appropriate tests and exams to stage the deformity and pathology. This allows practitioners to direct non-surgical care at the specific stage, providing the most effective treatment outcomes.

How To Treat Stage I AAF

The primary pathology in Stage I seems to be, by all accounts, tendinitis of the tibialis posterior tendon and physician should treat this accordingly.^1,3,4,7 Immobilization in a rigid walking boot with a high midsole rocker rests the tendon and allows recovery with the least amount of attenuation.

   The midtarsal joint, which is stabilized by the tibialis posterior, has significant sagittal plane motion in gait. Using a walking boot that immobilizes the frontal and transverse plane motion only places a greater lever arm of force on this joint and stretches the tendon that needs to rest. A high midsole rocker on the walking boot allows, during gait, the sagittal plane motion to occur external to the foot, therefore resting the tendon.

   Using a stabilizing functional foot orthosis (FFO) after the reduction of symptoms provides a more stable or rigid “bag of bones,” and provides normal motion with less effort from the tendon. The device should be rigid, deep and should maintain a more normal alignment to the subtalar joint and longitudinal arch while limiting midtarsal joint motion. This reduces the need for the stabilization effort of the tibialis posterior.