This condition is a progressive collapse of the tendons
and ligaments that hold up the foot?s arch.
This condition most commonly affects women. It typically occurs in only one foot, but in some cases, both feet are afflicted.
The most common cause of acquired adult flatfoot is posterior tibial tendon dysfunction. What causes adult acquired flat foot? Fracture or dislocation. Tendon laceration. Tarsal Coalition. Arthritis.
Neuroarthropathy. Neurological weakness.
Patients often experience pain and/or deformity at the ankle or hindfoot. When the posterior tibial tendon does not work properly, a number of changes can occur to the foot and ankle. In the earlier
stages, symptoms often include pain and tenderness along the posterior tibial tendon behind the inside of the ankle. As the tendon progressively fails, deformity of the foot and ankle may occur. This
deformity can include progressive flattening of the arch, shifting of the heel so that it no longer is aligned underneath the rest of the leg, rotation and deformity of the forefoot, tightening of
the heel cord, development of arthritis, and deformity of the ankle joint. At certain stages of this disorder, pain may shift from the inside to the outside aspect of the ankle as the heel shifts
outward and structures are pinched laterally.
First, both feet should be examined with the patient standing and the entire lower extremity visible. The foot should be inspected from above as well as from behind the patient, as valgus angulation
of the hindfoot is best appreciated when the foot is viewed from behind. Johnson described the so-called more-toes sign: with more advanced deformity and abduction of the forefoot, more of the
lateral toes become visible when the foot is viewed from behind. The single-limb heel-rise test is an excellent determinant of the function of the posterior tibial tendon. The patient is asked to
attempt to rise onto the ball of one foot while the other foot is suspended off the floor. Under normal circumstances, the posterior tibial muscle, which inverts and stabilizes the hindfoot, is
activated as the patient begins to rise onto the forefoot. The gastrocnemius-soleus muscle group then elevates the calcaneus, and the heel-rise is accomplished. With dysfunction of the posterior
tibial tendon, however, inversion of the heel is weak, and either the heel remains in valgus or the patient is unable to rise onto the forefoot. If the patient can do a single-limb heel-rise, the
limb may be stressed further by asking the patient to perform this maneuver repetitively.
Non surgical Treatment
Options range from shoe inserts, orthotics, bracing and physical therapy for elderly and/or inactive patients to reconstructive surgical procedures in those wishing to remain more active. These
treatments restore proper function and alignment of the foot by replacing the damaged muscle tendon unit with an undamaged, available and expendable one, lengthening the contracted Achilles tendon
and realigning the Os Calcis, or heel bone, while preserving the joints of the hindfoot. If this condition is not recognized before it reaches advanced stages, a fusion of the hindfoot or even the
ankle is necessary. Typically this is necessary in elderly individuals with advanced cases that cannot be improved with bracing.
If initial conservative therapy of posterior tibial tendon insufficiency fails, surgical treatment is considered. Operative treatment of stage 1 disease involves release of the tendon sheath,
tenosynovectomy, debridement of the tendon with excision of flap tears, and repair of longitudinal tears. A short-leg walking cast is worn for 3 weeks postoperatively. Teasdall and Johnson reported
complete relief of pain in 74% of 14 patients undergoing this treatment regimen for stage 1 disease. Surgical debridement of tenosynovitis in early stages is believed to possibly prevent progression
of disease to later stages of dysfunction.