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 normally 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 rarely 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 in order to abduct or push the foot out from the midline of the body.
Pain on the Medial Ankle With Weight Bearing
Inability to improve up on the feet without pain.
Too Many Toes Sign
Lateral subtalar joint (outside of the ankle) pain.
Common test to evaluate PTTD could be the 'too many foot 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 rear tibial tendon, the forefoot will abduct or transfer in relationship to the rest of the foot. In the event of PTTD, if the foot is viewed from guiding, the toes show up 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 sinus tarsi refers to a small tunnel 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 reduced, 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 pain.
There have been many proposed explanations for PTTD through the years given that this condition was first described by Kulkowski inThe most modern day explanation refers to an area of hypovascularity (limited blood flow) in the tendon just below the ankle. Tendon comes nearly all of its' nutritional support from synovial fluid produced by the outer lining of the tendon. Very small blood vessels also permeate the tendons sheath to arrive at tendons. This makes all tendon notoriously slow to recover. In the case of the posterior tibial tendon, this problem is exacerbated by a distinct section 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 an area where 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 interior of the ankle). The tendon then takes a dramatic turn towards the arch of the foot. If the muscle is put in 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 alterations course, the tibia acts as a wedge and could utilize enough force to actually damage or shatter 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 due to tightness in the leg 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 posterior tibial muscle to accept additional insert 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 result in tendonitis, partial tears of the tendon or perhaps complete muscle break.
- A number of categories have been developed to describe PTTD.
- The group as described by Johnson and Strom is most commonly used today.
- Stage I Tendon status Attenuated (lengthened) with tendonitis but no rupture Clinical findings Palpable pain in the medial arch.
- Foot is actually supple, flexible with too many foot sign X-ray/MRIMild to moderate tenosynovitis on MRI, no X-ray changes
- Stage II Tendon status Attenuated with possible partial or complete break Clinical findings Pain in arch.
- Not able to raise on foot.
- Too many toes indicator present X-ray/MRI MRI notes tear in muscle.
- 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 jotting 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 will require a mechanical solution.
- This means that treating PTTD with medication on your own is fraught with failure.
- Timely introduction of some form of mechanical support is imperative.
Surgical procedures which usually focus on primary repair of the posterior tibial tendon happen to be very unsuccessful. This is due to the fact that muscle heals slowly following damage and cannot be relied upon as a sole solution for PTTD cases. Medical success is usually attained by stabilization from the rearfoot subtalar joint) which significantly reduces the work performed by the rear tibial tendons.
Stage I May Respond to Sleep, Like a Walking Throw
Pain and inflammation might be controlled with anti-inflammatory medications. It is important to make sure that Stage I patients realize that the use of shoes with additional arch support as well as heel elevation, for the rest of their lives, is actually crucial. Arch support, whether built into the shoe or added as an orthotic, helps support the posterior tibial tendons and decrease its' function. Elevation of the heel, reduces equinus, one of the most significant contributing factors to PTTD. In the event that Stage I patients return to low heels without arch support, PTTD may recur.
Stage II patients, or Stage I patients that do not respond to rest and help, require surgical correction to be able to strengthen 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 wherever mild to be able 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 fix equinus. These methods require casting for a period of weeks following the method.
Stage III patients require stabilization of the rearfoot with procedures that fuse the primary joints of the arch and feet. These types of procedures are salvage procedures and require prolonged casting and disability following surgery. A common procedure forStage III is called triple arthrodesis which is a technique used to fuse the particular subtalar shared, the talo-navicular joint and 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 weak surgical applicants 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 tendon is the extension of the posterior tibial muscle that lies deep to the leg. 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 rear tibial muscle is the medial navicular the location where the tendon divides into nine different insertion site on the bottom of the foot.
The function of the posterior tibial tendon is always to plantarflex the foot on the toe away phase of the gait cycle and to support the medial arch.
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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, relocating to stage II.
- Stage II signs are seen with more regularity.
- Pain is present at the onset of standing and walking.
- Some limitation of the ability to raise up on the foot will be present.
- Stage III signs are severe with an inability to complete most normal daily activities such as laundry 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 muscle rupture, flexor hallucis longus tendonitis, gout, joint disease of the subtalar joint or a fracture of the posterior process of the particular talus.
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 acquired flatfoot deformity. J. Bone andJoint Surgery. 78-A;780, 1996
Johnson, K.A., Tibialis posterior tendon rupture. Clin. Orthop. 177:140-147, 1983
About the Particular 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.