Posterior Tibial Tendon Dysfunction

Introduction

Posterior tibial tendon dysfunction (PTTD) is the most common cause of flat feet in adults. When the tendon fails, it affects the surrounding tissue and will eventually lead to bone infiltration and deformity.

• PTTD is a progressive and debilitating disorder that can be devastating to patients due to the limitations of mobility with significant pain and weakness.
• Tissue degeneration begins well before clinical disease manifests. Early detection of PTTD may limit surgical repair strategies; if left to progress, revision surgery with osteotomy and arthrodesis becomes necessary[1]
• Risk factors for the disease include hypertension obesity diabetes prior trauma or steroid use.[2]

Posterior tibial tendon dysfunction (PTTD) is a progressive condition that can be divided into four categories[3].

• In the beginning there may be pain the area may be bright red and swollen. There are usually no symptoms during running but symptoms can occur during running.
• Later as the entrance begins to flatten out there may still be pain in the foot and ankle but at this point the foot and ankle begin to shift outwards and the toes roll inward.
• As PTTD progresses further, the girdle becomes even more flat and the pain tends to shift to the back of the leg below the ankle. The nerves are severely damaged and arthritis is common in the legs. In severe cases arthritis can also occur in the ankle. [4] .

Clinically Relevant Anatomy

• The posterior tibialis originates from the posteromedial fibula of the tibia and the interosseous membrane.
• It passes through the deep dorsal surface of the foot and its muscle passes behind the medial malleolus.
• Blood supply to the veins is very poor in this area and is where ruptures are most common.
• Close to the insertion site, the tendon splits into the main femur and recurrent segments with the main element anchoring the plantar surface on the navicular tuberosity to the third fourth second metatarsals on the second and third cuneiforms and the cuboid. The recurring element sticks support for supporting the hips.

The tibialis posterior acts as an important stabilizer of the mid-longitudinal arch and the main inverter of the midfoot.

Its pull also raises the mid-length arch allowing the hind leg and mid leg to become a solid unit. This allows the gastrocnemius to be more active during the gait cycle[1].

When damaged the resulting pes planus foot can be enlarged and cause significant stress to the surrounding tissues and soft tissues[5].

Etiology

Researchers have proposed a number of mechanisms for posterior tibial tendon (PTT) degeneration.

• The most common cause of PTT degeneration is attributed to repetitive loading that causes microtrauma and progressive failure.
• The vascular region behind the ankle does exist and may also contribute to the disease.
• The anatomical course of the posterior tibial tendon may also contribute, as the tendon does make a sharp turn around the medial malleolus, putting a lot of tension on the tendons distal to and posterior to the medial malleolus (adjacent tendon, flexor hallucis) The longus and flexor digitorum longus do not make sharp turns).
• Other possible causes are – constriction below the flexor retinaculum and abnormal anatomy of degenerative changes in the talus associated with osteoarthritis and pre-existing flat feet. [2]

Epidemiology

The overall incidence of the disease is thought to range from 3.3% to 10%, depending on the sex and age of the patient.

• PTTD is associated with adult-acquired flatfoot defects, which may lead to its misdiagnosis, meaning that the true prevalence may be much higher than indicated in the literature. [2]
• Conditions such as diabetes, hypertension, obesity, previously operated foot/ankle trauma, and steroid use are found in up to 60% of patients.
• Although many of these risk factors are systemic, usually only one side is affected; bilateral disease is rare [1]

Risk factors to get PTTD are:

1. Elderly: especially middle-aged women [6][7], the prevalence of this population is as high as 10%.
2. Young athletes [6]
3. Hypertension [6][7]
4. Obesity [6][7]
5. Diabetes mellitus [6][7]
6. Seronegative arthropathies [6]
7. Accessory navicular bone [6]
8. Ligamentous laxity [7]
9. Pes planus (flatfeet) [7]
10. Steroid therapy [6][7]
11. Accessory navicular: May interfere with posterior tibial tendon function [6]
12. Overuse [4] [8]
13. Previous trauma (certain types of ankle fractures) [9]
14. Steroid injections[9]
15. Psoriatic Arthritis/Rheumatoid Arthritis

Characteristics / Clinical Presentation

Most patients report a slow and insidious onset of unilateral flatfoot deformity.

• A history of trauma may be present in up to 50% of cases.
• Patients describe pain and swelling on the inside of the foot and ankle, which may be exacerbated by activity.
• Standing on your toes can be painful and difficult, like going up and down stairs or walking on an uneven surface.
• Patients may complain of increased pre-existing claudication.
• With collapse of the medial longitudinal arch, foot deformity increases; in this case, patients may describe abnormal wear on their shoes.
• In severe deformities, the distal fibula will make contact with the calcaneus and pain will shift to the outside of the foot; patients at this stage may describe a sensation of walking on the inside of the ankle. [1]
• Static/dynamic foot change (pes planus)
• Impaired balance
• Impaired MMT PF/IV
• Difficulty/impossibility to perform unilateral heel raises. Limited calcaneal varus on ascent
• Impaired subtalar mobility 

The Posterior Tibial Tendon During Gait

The function of healthy tendons is to plantarflex the ankle in inversion and raise the medial longitudinal arch of the foot (it appears to be the primary stabilizer of this arch). Elevation of the medial longitudinal arch results in locking of the entire midtarsal bone, thus Metatarsal and hindlimb hardening.

• This allows the muscle gastrocnemius to act more efficiently during gait.
• With PTTD, other joint capsules and ligaments become weak. The subtalar joint is everted and the foot is abducted (talonavicular joint), with the heel in an everted position.
• A flat arch can lead to acquired flat feet in adults.
• The gastrocnemius cannot act without the posterior tibial tendon, which can affect balance and gait.

The lower panel shows different intramuscular EMG activity activated in the posterior tibia during walking between acute stage II PTTD and unaffected individuals.

Differences in muscle activation:

• Participants with PTTD showed significantly greater tibialis posterior EMG amplitudes during the second half of the stance phase.
• They walked with pronated feet and showed increased tibialis posterior activity compared to participants without PTTD. [10]

Differential Diagnosis

While posterior tibial tendon dysfunction is the most common cause of acquired flatfoot deformity in adults, there are many other associated conditions. The diagnoses listed below may closely resemble PTTD and should be considered during the evaluation:

• Tarsal coalition
• Inflammatory arthritis
• Charcot arthropathy
• Neuromuscular disease
• Traumatic destruction of the midfoot ligaments [2]

Diagnostic Procedures

In addition to clinical diagnosis, radiographic evaluation can be used to evaluate for deformity and possible degenerative arthritis or other causes of flat feet. MRI has the highest sensitivity, specificity and accuracy, but ultrasound is cheaper and almost as sensitive and specific as ultrasound MRI.

Clinical trials for PTTD (see review for more information) [11]:

• Too many toes sign [12]
• Single leg heel raise
• First metatarsal rise sign[13]
• Plantar flexion and inversion against resistance
• Mobility of TN and CC joints
• Weightbearing X-Rays

Stages of PTTD

According to Johnson and Strom[4][8][12][12]:

1. Stage I: The posterior tibial tendon is intact and inflamed without deformity and mildly swollen
2. Stage II: Posterior tibial tendon dysfunction Acquired flatfoot but passively correctable Usually unable to perform heel elevation
3. Stage III: Degenerative change of the subtalar joint, deformity and fixation
4. Stage IV (Myerson): Lateral tibiotalar degeneration due to talus valgus

Stage I

• Deformity: tenosynovitis
• Physical examination: single leg toe lift test (+)
• Radiography: normal

Stage IIA

• Deformity: flat foot deformity flexible rear foot normal forefoot
• Physical examination: single leg heel elevation (-) mild sinus tarsi pain
• Radiography: arch collapse deformity

Stage IIB

• Deformity: Flatfoot deformity with mild hindfoot/hindfoot forefoot abduction
• Physical exam: Same stage IIA
• Radiography: same stage IIA

Stage III

• Deformity in stage II becomes fixed rigid or irreversible
• Deformity: flatfoot deformity forefoot stiffness abduction hindfoot/hindfoot valgus stiffness
• Physical examination: sever sinus tarsi pain one leg heel raise test (-) .
• Radiography: arch collapse deformity.

Stage IV

• Deformity: flatfoot deformity rigid forefoot abduction hindfoot/hindfoot stiffness valgus deltoid ligament compromise
• Physical examination: one leg for foot test (-) severe sinus tarsi pain toe pain
• Radiography arch collapse deformity subtalar arthritis talar tilt ankle mortise

Examination

Posterior tibial tendon dysfunction can be diagnosed based on history and objective examination.

Subjective

Before clinical examination, the patient should be asked a series of questions to exclude other problems. It is important to detect posterior tibial tendon dysfunction (PTTD) at an early stage to prevent permanent deformity of the foot/ankle so a physical examination is done it is important [6].

Objective

The physiotherapist can palpate the posterior tibial tendon from the apex of the medial malleolus to the insertion point to control its integrity and to monitor possible pain and inflammation commonly associated with PTTD in the first half. In the later stages, the deformity may progress and pes planus may appear. It it is important to examine the entire lower body and not just the foot because valgus in the knees can highlight the appearance of pes planus. A healthy person has 5° valgus in the hindfoot in patients with PTTD the valgus is increased and the arrest in the forefoot is also more pronounced[14] The a physiotherapist can determine the severity of the pes planus by assessing the number of fingers that can be moved under the midfoot[6].

Basic tests for PTTD/AAFD include:[15]

• Too many fingers means: the foot must be viewed from behind and above. Symptoms of too many toes are a method of examination from the outside. In this way it can be determined if there is abduction of the forefoot and valgus angulation of the hindfoot. It depends on how many toes you can see from it behind. Depending on the affected foot it will be more than one and a half to two toes check the Foot Posture Index as well
• Two-legged heel rise: to move with both feet from a flat-footed position to a position on the toes. Patients in stage I dysfunction can do this but it is painful. Patients with stage II III or IV dysfunction are unable to perform heel elevation. When a patient stands on his feet, the heel of the affected foot will you don’t have to lean into it; the straight leg will be in inversion while the affected hind leg will be in valgus.
• One-leg lift: patients cannot use the other leg for a single heel;
• First sign of metatarsal raising[13]: the patient stands on both feet the foot of the affected foot is grasped manually and rotated backward. When the patient develops PTTD the head of metatarsal I is elevated while the normal metatarsal I stays down;
• Plantarflexion and rotation of the foot against resistance: to evaluate the power of the tibialis posterior.

Outcome Measures

• Foot Function Index (FFI)[11]
• 5-Minute Walk Test [11]
• Tools for recording kinematics from the tibial calcaneus and first metatarsal: e.g. Milwaukee Foot Model [11][16].

Medical Management

• Treatment of posterior tibial tendon dysfunction is a difficult issue to decide whether patients need surgical or non-surgical treatment with variables to be considered by the attending physician. [17] .
• Non-invasive treatments such as orthosis and physical therapy [18] are preferable because they do not damage surrounding healthy tissue but surgical treatment is only necessary when non-surgical treatment fails. [17] [19] .
• There is clear evidence that quality of life in patients with posterior tibial dysfunction is significantly affected.
• Evidence suggests that early radical intervention can significantly improve quality of life in terms of disability function and pain[20].
• All Stages initially:
  • Conservative use of NSAIDs and functional changes. It is also indicated for non-surgical or demanding elderly patients.
• Stage 1:
  • Conservative management with walking shoes or inserts for up to 3 to 4 weeks to heal the posterior tibial tendon consumed a remarkable amount of energy physical therapy followed.
  • If immobilization and physical therapy are successful, conversion to conventional orthotics or AFOs is warranted to maintain recovery. Emphasis on medial forefoot posting is critical.
  • Conservative treatment should be 3 to 4 months and if it fails then surgical intervention may be appropriate. Tenosynovectomy with tubularization may be indicated
• Stage 2A:
  • Conservative immobilization and physical therapy with orthotics or ankle-foot orthosis (AFO) as recommended in phase 1
  • Surgical treatment is a medial calcaneal osteotomy in which the posterior cartilage is trimmed and repaired. Accessories may include any/all of the following: flexor digitorum tendon (FDL) transfer spring ligament reconstruction or Achilles tendon lengthening.
• Stage 2B:
  • All previously listed procedures in Stage 2A +/- lateral column lengthening or isolated subtalar joint arthrodesis
• Stage 3:
  • Conservative treatment as described above.
  • Surgical treatment is generally warranted as it involves hindfoot arthrodesis and is indicated for the most common medial bilateral or triple arthrodesis (subtalar calcaneocuboid and talonavicular arthrodesis) with or without deltoid ligament repair.
• Stage 4
  • Conservative treatment as described above.
  • Surgical treatment is usually necessary as it involves vascular changes in the ankle as well as the hind leg.
  • Tibiotalocalcaneal (TTC) arthrodesis results in stability of the hindfoot with significant valgus contact with the talus in the ankle mortise.[2]

Physical Therapy Management

The key to success is early detection of dysfunction and conservative management to prevent chronicity.

The goals of non-surgical treatment include.

• Elimination of clinical symptoms,
• Development of hind leg alignment and
• Prevention of progressive leg cramps.
• Patient reeducation: Functional constraints and change
• Relief provided by prescribing medial arch support insoles or custom orthotics (necessary in many cases).

Conservative use of exercises and topical medications for Phases I and II is the first option. [21] no. Options include:

• Orthotic devices anaa bracing: de boa arch no.
• A walking cast or CAM boot can be used to immobilize the leg. If this brings relief the patient may have an orthotic or adjustable shoe or an ankle-foot orthosis (AFO).
• Achilles tendon extension and tibialis posterior strength concentric/eccentric training of the posterior tibialis. and non-steroidal anti-inflammatory drugs[1] .
• Immobilization: a short leg cast or boot that heals muscles or avoids full weight bearing.
• Medications: non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen help reduce pain and inflammation.
• Shoe modifications: advise modifications such as special inserts designed to improve arch support. [4] .
• Toe Pick-Ups:The exercise consists of picking up small objects such as pebbles marbles or small toys with your toes and placing them in a bucket or other container.
• Arch Strengthening Caterpillar: the arch strengthening caterpillar exercise begins by lying on your back with your knees bent and your feet flat on the floor about two feet from your back. Lift both legs and pull your toes back towards your heels. Relax and stretch your legs a little back to your butt. Repeat the process so your legs don’t get too close to your glutes in a caterpillar motion. Once your feet are almost touching your heels, repeat the sequence in reverse slowly pulling your feet away from behind you in the same butterfly motion.
• Arch Raises: Sit on a chair with your back straight with your knees bent at 90 degrees and your feet flat on the floor. Lift the front of one leg off the ground without bending your ankle or lifting your heel. (It’s much harder than it sounds!) When done correctly you should feel your muscles tighten in your lower legs and thighs.
• Line Writing: You can strengthen all of your feet by imagining a pencil between your toes pointing the toes outward and “writing” the lines in the air in front of you[22].

Nonoperative management should be tried for up to 4 months; if there is no improvement during this time, tenosynovectomy or debridement may be required. [1]

Orthotics:

Optimal foot load management with foot orthotics and proper footwear is the most important aspect of treatment. Depending on the progression of the pathology, this can be managed step-by-step with over-the-counter non-personalized foot orthotics, followed by personalized foot orthotics Orthosis, and finally a semi-rigid ankle-foot orthosis [21]. For stage I disease, nonsurgical treatment should be attempted for at least 3 to 4 months. Patients with acute tenosynovitis require short walking casts or removable cast boots. If symptoms improve Once immobilized, the patient can then be fitted with a custom orthotic or ankle foot orthosis (AFO). The orthosis should be a full-length semi-rigid full-contact insert with a medial post. The main function of orthotics is to provide arch support and correct the elastic part of the arch deformity.

Treatment options for each stage of PTTD depend on whether acute inflammation is present and whether the foot deformity is fixed or flexible:

1. Phase 1: Acute: 4-8 weeks immobilized RICE; Chronic: flat shoes and corrective orthotics or AFO straps
2. Phase 2: Acute 4-8 weeks Immobilized RICE; Chronic: Corrective lace-up orthotics and flat shoes
3. Phase 3: Lace-up custom or semi-rigid shoes and adaptive orthotics
4. Stage 4: Lace-up custom or semi-rigid shoes and adaptive orthotics

Prognosis

• Posterior tibial tendon dysfunction is a progressive condition that will continue to get worse if left untreated.
• Early detection and intervention will help slow progression.
• Patients provided with custom orthotics and rehabilitation have been shown to experience significant improvement.
• In a recent study by Alvarez et al. about 89% of their patients with PTTD stages I and II responded to orthotics and PT. Almost all of these patients had regained complete recovery by 4 months.
• The outcome of surgical treatment is highly unpredictable and a return to premorbid status should not be guaranteed. Patients may continue to have some residual effects after reconstructive surgery[1]

Clinical Bottom Line

PTTD requires an interprofessional team approach that includes physician specialist physiotherapists and physicians who all work collaboratively across disciplines to achieve optimal patient outcomes.[2]

• Posterior tibial tendon dysfunction tendency is a slow onset condition that primarily affects obese middle-aged women.
• Risk factors include obesity hypertension diabetes steroid use and coronary artery disease.
• Patients may complain of pain and inflammation around the mid toe with difficulty moving or aggravation of an existing ulcer.
• Examination may show that it is easier during periods of muscle stiffness to perform a single leg raise or “too many fingers” when viewing the standing foot from the outside.
• X-ray and MRI can confirm diagnosis help stage the disease and help with preoperative planning.
• The disease as a process is not well known and early stages of the disease can be detected but early treatment can prevent disability and the need for surgery.[1]