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.
As discussed above, many different problems can create a painful flatfoot. Damage to the posterior tibial tendon is the most common cause of AAFD. The posterior tibial tendon is one of the most
important tendons of the leg. It starts at a muscle in the calf, travels down the inside of the lower leg and attaches to the bones on the inside of the foot. The main function of this tendon is to
support the arch of your foot when you walk. If the tendon becomes inflamed or torn, the arch will slowly collapse. Women and people over 40 are more likely to develop problems with the posterior
tibial tendon. Other risk factors include obesity, diabetes, and hypertension. Having flat feet since childhood increases the risk of developing a tear in the posterior tibial tendon. In addition,
people who are involved in high impact sports, such as basketball, tennis, or soccer, may have tears of the tendon from repetitive use. Inflammatory arthritis, such as rheumatoid arthritis, can cause
a painful flatfoot. This type of arthritis attacks not only the cartilage in the joints, but also the ligaments that support the foot. Inflammatory arthritis not only causes pain, but also causes the
foot to change shape and become flat. The arthritis can affect the back of the foot or the middle of foot, both of which can result in a fallen arch. An injury to the tendons or ligaments in the foot
can cause the joints to fall out of alignment. The ligaments support the bones and prevent them from moving. If the ligaments are torn, the foot will become flat and painful. This more commonly
occurs in the middle of the foot (Lisfranc injury), but can also occur in the back of the foot. Injuries to tendons of the foot can occur either in one instance (traumatically) or with repeated use
over time (overuse injury). Regardless of the cause, if tendon function is altered, the forces that are transmitted across joints in the foot are changed and this can lead to increased stress on
joint cartilage and ligaments. In addition to tendon and ligament injuries, fractures and dislocations of the bones in the midfoot can also lead to a flatfoot deformity. People with diabetes or with
nerve problems that limits normal feeling in the feet, can have collapse of the arch or of the entire foot. This type of arch collapse is typically more severe than that seen in patients with normal
feeling in their feet. In addition to the ligaments not holding the bones in place, the bones themselves can sometimes fracture and disintegrate without the patient feeling any pain. This may result
in a severely deformed foot that is very challenging to correct with surgery. Special shoes or braces are the best method for dealing with this problem.
Posterior tibial tendon insufficiency is divided into stages by most foot and ankle specialists. In stage I, there is pain along the posterior tibial tendon without deformity or collapse of the arch.
The patient has the somewhat flat or normal-appearing foot they have always had. In stage II, deformity from the condition has started to occur, resulting in some collapse of the arch, which may or
may not be noticeable. The patient may feel it as a weakness in the arch. Many patients initially present in stage II, as the ligament failure can occur at the same time as the tendon failure and
therefore deformity can already be occurring as the tendon is becoming symptomatic. In stage III, the deformity has progressed to the extent where the foot becomes fixed (rigid) in its deformed
position. Finally, in stage IV, deformity occurs at the ankle in addition to the deformity in the foot.
Your podiatrist is very familiar with tendons that have just about had enough, and will likely be able to diagnose this condition by performing a physical exam of your foot. He or she will probably
examine the area visually and by feel, will inquire about your medical history (including past pain or injuries), and may also observe your feet as you walk. You may also be asked to attempt standing
on your toes. This may be done by having you lift your ?good? foot (the one without the complaining tendon) off the ground, standing only on your problem foot. (You may be instructed to place your
hands against the wall to help with balance.) Then, your podiatrist will ask you to try to go up on your toes on the bad foot. If you have difficulty doing so, it may indicate a problem with your
posterior tibial tendon. Some imaging technology may be used to diagnose this condition, although it?s more likely the doctor will rely primarily on a physical exam. However, he or she may order
scans such as an MRI or CT scan to look at your foot?s interior, and X-rays might also be helpful in a diagnosis.
Non surgical Treatment
Flatfoot deformity can be treated conservatively or with surgical intervention depending on the severity of the condition. When people notice their arches flattening, they should immediately avoid
non-supportive shoes such as flip-flops, sandals or thin-soled tennis shoes. Theses shoes will only worsen the flatfoot deformity and exacerbate arch pain. Next, custom orthotics are essential for
people with collapsed arches. Over-the-counter insoles only provide cushion and padding to the arch, whereas custom orthotics are fabricated to specifically fit the patient?s foot and provide support
in the arch where the posterior tibial tendon is unable to anymore. Use of custom orthotics in the early phases of flatfoot or PTTD can prevent worsening of symptoms and prevent further attenuation
or injury to the posterior tibial tendon. In more severe cases of flatfoot deformity an ankle foot orthosis (AFO) such as a Ritchie brace is needed. This brace provides more support to the arch and
hindfoot rather than an orthotic but can be bulky in normal shoegear. Additional treatment along with use of custom orthotics is use of non-steroidal anti-inflammatories (NSAIDS) such as Advil,
Motrin, or Ibuprofen which can decrease inflammation to the posterior tibial tendon. If pain is severe, the patient may need to be placed in a below the knee air walker boot for several weeks which
will allow the tendon to rest and heal, especially if a posterior tibial tendon tear is noted on MRI.
Until recently, operative treatment was indicated for most patients with stage 2 deformities. However, with the use of potentially effective nonoperative management , operative treatment is now
indicated for those patients that have failed nonoperative management. The principles of operative treatment of stage 2 deformities include transferring another tendon to help serve the role of the
dysfunctional posterior tibial tendon (usually the flexor hallucis longus is transferred). Restoring the shape and alignment of the foot. This moves the weight bearing axis back to the center of the
ankle. Changing the shape of the foot can be achieved by one or more of the following procedures. Cutting the heel bone and shifting it to the inside (Medializing calcaneal osteotomy). Lateral column
lengthening restores the arch and overall alignment of the foot. Medial column stabilization. This stiffens the ray of the big toe to better support the arch. Lengthening of the Achilles tendon or
Gastrocnemius. This will allow the ankle to move adequately once the alignment of the foot is corrected. Stage 3 acquired adult flatfoot deformity is treated operatively with a hindfoot fusion
(arthrodesis). This is done with either a double or triple arthrodesis - fusion of two or three of the joints in hindfoot through which the deformity occurs. It is important when a hindfoot
arthrodesis is performed that it be done in such a way that the underlying foot deformity is corrected first. Simply fusing the hindfoot joints in place is no longer acceptable.