Posterior Tibial Tendon Dysfunction (PTTD)
Posterior tibial tendon dysfunction (PTTD), also known as posterior tibial tendonitis, is one of the leading causes of acquired flatfoot in adults. The onset of PTTD may be slow and progressive or sudden. An abrupt starting point is typically linked to some form of trauma, whether it be simple (stepping down off a curb or ladder) or severe (falling from a height or car accident). PTTD is hardly ever seen in children and increases in frequency with age.
The Characteristic Finding of PTTD Include;
Loss of medial arch height.
Edema (Swelling) of the Medial Ankle
Loss of the ability to resist force to be able to abduct or push the foot out from the midline of the body.
Pain on the Medial Ankle With Weight Bearing
Inability to raise up on the foot without pain.
Too Many Toes Sign
Lateral subtalar joint (outside of the ankle) pain.
Common test to evaluate PTTD could be the 'too many toes sign'. The way too many toes sign' is a test used to determine abduction deviation away from the midline of the body) from the forefoot. With damage to the posterior tibial tendon, the forefoot will abduct or transfer in relationship to the rest of the foot. In the event of PTTD, when the foot is viewed from guiding, the toes seem as 'too many' on the outside of the foot due to abduction of the forefoot.
Advanced cases of PTTD, in addition to the pain of the tendon itself, pain will also be noted at the sinus tarsi. The nose tarsi refers to a small tube or divot on the outside of the ankle that can actually be felt. This tunnel is the entry to the subtalar joint. The subtalar joint is the joint that controls the side to side motion of the foot, motion that would occur with uneven surfaces or sloped hills. As PTTD progresses and the ability of the posterior tibial tendon to support the arch becomes declined, the arch will collapse overloading the subtalar joint. As a result, there is increased pressure applied to the joint areas of the lateral aspect of the subtalar joint, resulting in discomfort.
There have been many proposed explanations for PTTD over the years given that this condition was first described by Kulkowski inThe most modern explanation refers to an area of hypovascularity (limited blood flow) in the tendon just below the ankle. Tendon gets most of its' nutritional support from synovial fluid produced by the actual outer lining of the tendon. Very small blood vessels also permeate the tendons sheath to arrive at muscle. This makes all tendon notoriously slow to cure. In the case of the posterior tibial tendons, this problem is exacerbated by a distinct part of bad blood flow hypovascularity). This area is located in the posterior tibial tendon just below or distal to the inside ankle bone (medial malleolus).
Tendon is also many vunerable to fatigue and failure at a region in which the tendon changes direction. As the posterior tibial tendon descends the leg and comes to the inside of the ankle, the tendon follows a well defined groove in the back of the tibia (bone of the lining of the ankle). The tendon then takes a dramatic turn towards the arch of the foot. If the tendons is put into a situation where significant load is applied to the foot, the tendon responds by pulling up as the load of the body (in addition to be able to gravity) pushes down. At the location where the tendon changes course, the tibia acts as a wedge and may apply enough force to actually damage or break the tendon.
Equinus is Also a Contributing Factor to PTTD
Equinus is the term used to describe the ability or lack of ability to dorsiflex the foot on the ankle (move the toes toward you).Equinus is usually because of tightness in the calf muscle tissue, also known as the gastroc-soleal complex (a combination of the gastrocnemius and soleus muscles). Equinus may also be due to a bony block in the front of the ankle. The presence of equinus forces the rear tibial tendons to accept additional fill during gait.
Additional contributing factor to the onset of PTTD may include hypertension, diabetes, peripheral neuropathy, smoking or arthritis.
- The progression of PTTD may well lead to tendonitis, partial tears of the tendon or complete muscle shatter.
- Several categories have been developed to describe PTTD.
- The category as described by Johnson and Strom is most commonly used today.
- Stage I Tendon status Attenuated (lengthened) with tendonitis but absolutely no rupture Clinical findings Palpable pain in the medial arch.
- Foot is supple, versatile with way too many foot indicator X-ray/MRIMild to moderate tenosynovitis on MRI, no X-ray changes
- Stage II Tendon status Attenuated with possible partial or complete rupture Clinical findings Pain in arch.
- Not able to raise on toes.
- A lot of toes indication present X-ray/MRI MRI notes tear in tendon.
- X-ray noting abduction of forefoot, collapse of talo-navicular joint
Stage III Tendon status Severe degeneration with likely ruptureClinical findings Rigid flatfoot with inability to raise up on toes X-ray/MRI MRI shows tear in tendon. X-ray noting abduction of forefoot, collapse of talo-navicular joint.
- Treatment for PTTD is dependant after the clinical stage and the health status of the patient.
- It is important to recognize thatPTTD is a mechanical problem that needs a mechanical solution.
- This means that treating PTTD with medication on your own is fraught with failure.
- Timely introduction of some form of physical support is imperative.
Surgical procedures which focus on primary repair of the posterior tibial tendon are very unsuccessful. This is due to the fact that tendons heals slowly following damage and cannot be relied upon as a sole solution for PTTD cases. Surgical success is usually accomplished through stabilization of the rearfoot subtalar joint) which significantly reduces the work carried out by the rear tibial tendons.
Stage I Might Respond to Rest, for Instance a Walking Cast
Pain and inflammation may be controlled with anti-inflammatory medications. It is important to make certain that Stage I patients realize that the use of shoes with additional arch support and heel elevation, for the rest of their lives, is imperative. Arch support, whether constructed into the shoe or added as an orthotic, helps support the posterior tibial tendon and decrease its' work. Elevation of the heel, reduces equinus, one of the most significant contributing factors to PTTD. If Stage I patients go back to low heels with out arch support, PTTD will recur.
Stage II patients, or Stage I patients that do not respond to rest and help, require surgical correction in order to stabilize the subtalar joint prior to further damage to the posterior tibial tendon. Subtalar arthroeresis is a procedure used to stabilize the subtalar joint. Arthroeresis is a term that means the motion of the joint is blocked without fusion. Subtalar arthroeresis can only be used in cases of Stage I or II where mild to moderate deformation of the arch has occurred and MRI findings show the tendon to be only partially ruptured. Subtalar arthroeresis is typically performed in conjunction with anAchilles tendon lengthening procedure to improve equinus. These procedures require casting for a period of weeks following the procedure.
Stage III patients require stabilization of the rearfoot with procedures that fuse the primary joints of the arch and base. These types of procedures are salvage procedures as well as require prolonged casting and disability following surgery. A common procedure forStage III is called triple arthrodesis which is a technique used to fuse the actual subtalar shared, the talo-navicular joint and also the calcaneal cuboid joint.
PTTD is a condition that increases in frequency with age and the prevalence of poor health indicators such as diabetes and obesity. As a result, many patients with PTTD are poor surgical candidates for correction of PTTD. Prosthetics such as an ankle foot orthotic (AFO), Arizona Brace or other bracing may be very helpful to control the symptoms of PTTD. Anatomy:
The posterior tibial muscle is the extension of the posterior tibial muscle that lies deep to the calf. The origin of the posterior tibial muscle is the posterior aspect of both the tibia and fibula and the interosseus membrane. The insertion of the posterior tibial muscle is the medial navicular the location where the tendon divides into nine different insertion web site on the bottom of the foot.
The function of the posterior tibial tendon would be to plantarflex the base in the toe off phase of the gait cycle and to stabilize the medial arch.
The symptoms of stage I PTTD include a dull ache of the medial arch. The pain become worse with activity, better on days with limited time on the feet. Considerable activity may result in a partial rupture of the tendon, shifting to stage II.
- Stage II signs and symptoms are seen with more regularity.
- Pain is present at the onset of standing and walking.
- Some constraint of to be able to raise up on the foot will be present.
- Stage III symptoms are severe with an inability to accomplish most normal daily activities such as washing or going to the store.
- Collapse of the medial arch will be obvious.
- Abduction of the forefoot will show 'too many toes sign'.
Conditions that may resemble PTTD include tarsal tunnel syndrome, tibial stress fractures, posterior tibial tendon rupture, flexor hallucis longus tendonitis, gout, joint disease of the subtalar joint or a fracture of the posterior process of the talus.
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Additional References Include;
Cantanzariti, A.R., Lee, M.S., Mendicino, R.W. PosteriorCalcaneal Displacement Osteotomy regarding Adult Acquired Flatfoot. J.of Foot and Ankle Surgery. 39-1: 2-14, 2000
- Myerson, M.S., Corrigan, J.
- Treatment of posterior tibial muscle dysfunction with flexor digitorum longus tendon transfer and calcaneal osteotomy.
- Orthopedics 19:383-388, 1996
Myerson, M.S. Adult purchased flatfoot deformity. J. Bone andJoint Surgery. 78-A;780, 1996
Johnson, K.A., Tibialis posterior tendons rupture. Clin. Orthop. 177:140-147, 1983
About the Author:Jeffrey a
Oster, DPM, C.Ped is a board certified foot and ankle surgeon. Dr. Oster is also board certified in pedorthics. Doctor. Oster is medical director of Myfootshop.com and is in active practice in Granville, Ohio.