Flatfoot deformity is a general term used to describe a person whose arches are slowly dropping to the ground, aka ?fallen arches.? Adult-acquired flatfoot deformity can be caused by several factors, but the most common is abnormal functioning of the posterior tibial tendon in the foot and ankle. The posterior tibial tendon is the primary tendon that supports the arch. If this tendon begins to elongate from a sustained, gradual stretch over a long period of time, then the arch will progressively decrease until full collapse of the arch is noted on standing. What makes this tendon elongated? Biomechanical instability of the foot such as over-pronation or an accessory bone at the insertion site of the tendon are the primary causes for posterior tibial tendon dysfunction.
Posterior tibial tendon dysfunction is the most common cause of acquired adult flatfoot. Sometimes this can be a result of specific trauma, but usually the tendon becomes injured from wear and tear over time. This is more prevalent in individuals with an inherited flat foot but excessive weight, age, and level of activity are also contributing factors.
Patients will usually describe their initial symptoms as “ankle pain”, as the PT Tendon becomes painful around the inside of the ankle joint. The pain will become more intense as the foot flattens out, due to the continued stretching and tearing of the PT Tendon. As the arches continue to fall, and pronation increases, the heel bone (Calcaneus) tilts into a position where it pinches against the ankle bone (Fibula), causing pain on both the inside and outside of the ankle. As the foot spends increased time in a flattened, or deformed position, Arthritis can begin to affect the joints of the foot, causing additional pain.
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
PTTD is a progressive condition. Early treatment is needed to prevent relentless progression to a more advanced disease which can lead to more problems for that affected foot. In general, the treatments include rest. Reducing or even stopping activities that worsen the pain is the initial step. Switching to low-impact exercise such as cycling, elliptical trainers, or swimming is helpful. These activities do not put a large impact load on the foot. Ice. Apply cold packs on the most painful area of the posterior tibial tendon frequently to keep down the swelling. Placing ice over the tendon immediately after completing an exercise helps to decrease the inflammation around the tendon.
Nonsteroidal Anti-inflammatory Medication (NSAIDS). Drugs, such as arcoxia, voltaren and celebrex help to reduce pain and inflammation. Taking such medications prior to an exercise activity helps to limit inflammation around the tendon. However, long term use of these drugs can be harmful to you with side effects including peptic ulcer disease and renal impairment or failure. Casting. A short leg cast or walking boot may be used for 6 to 8 weeks in the acutely painful foot. This allows the tendon to rest and the swelling to go down. However, a cast causes the other muscles of the leg to atrophy (decrease in strength) and thus is only used if no other conservative treatment works. Most people can be helped with orthotics and braces. An orthotic is a shoe insert. It is the most common non-surgical treatment for a flatfoot and it is very safe to use. A custom orthotic is required in patients who have moderate to severe changes in the shape of the foot. Physiotherapy helps to strengthen the injured tendon and it can help patients with mild to moderate disease of the posterior tibial tendon.
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.