AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

History of the Procedure

Kulowski first described tenosynovitis of the posterior tibial tendon in 1936. Key described surgical findings of partial posterior tibial tendon rupture in 1953. In 1974, Goldner et al described the surgical treatment of 9 patients with posterior tibial tendon dysfunction. In the early 1980s, Jahss (1982), Mann (1982), and Johnson (1983) recognized posterior tibial tendon dysfunction as a common cause of acquired adult flatfoot.

Problem

Adult flatfoot refers to a deformity that develops after skeletal maturity is reached. It should be differentiated from constitutional flatfoot, which is a common congenital nonpathologic foot morphology.

Etiology

There are numerous causes of acquired adult flatfoot, including fracture or dislocation, tendon laceration, tarsal coalition, arthritis, neuroarthropathy, neurologic weakness, and iatrogenic causes. The most common cause of acquired adult flatfoot is posterior tibial tendon dysfunction. This article focuses primarily on the diagnosis and treatment of this condition.

The etiology of posterior tibial tendon dysfunction is varied; it is attributed to degenerative, inflammatory, and traumatic causes. In 1 study, 60% of patients were obese or had diabetes mellitus, hypertension, previous surgery or trauma to the medial foot, or treatment with steroids. Myerson has described 2 subsets of patients with posterior tibial tendon dysfunction. One patient group was younger with associated enthesopathies at multiple sites, a higher incidence of HLA-B27 positivity, and a significant family history for inflammatory disease and psoriasis, thus suggesting a seronegative spondyloarthropathy. The other patient group was older and had isolated dysfunction, suggesting a purely mechanical degenerative cause.

Arthropathies can result in posterior tibial tendon dysfunction as well. In 1 study, 11% of 99 rheumatoid patients were found to have posterior tibial tendon pathology. A zone of tendon hypovascularity exists 1-1.5 cm distal to the medial malleolus, continuing 14 mm distally. Poor blood supply in this area of the tendon, where it takes a sharply curving course around the medial malleolus, could result in tendon degeneration and may explain a mechanical cause for tendon rupture.

A study by Dyal et al compared weight-bearing radiographs of symptomatic feet with posterior tibial tendon dysfunction to those of the contralateral asymptomatic feet. Interestingly, there was strong correlation between the measurements of both feet, leading the authors to suggest that a predisposing constitutional flatfoot may be a possible etiologic factor in the development of dysfunction. The authors cautioned against using radiographic measurements alone for diagnosis.

Pathophysiology

The medial longitudinal arch has both passive and active support. The 3 most important static contributors to arch stability in order of importance are the plantar fascia, the long and short plantar ligaments, and the spring ligament (calcaneonavicular ligament). The spring ligament forms a sling for the talar head, which prevents medial and plantar migration of the talar head and provides static arch support. The major dynamic stabilizer for the arch is the posterior tibial tendon.

Contraction of the posterior tibial tendon causes inversion of the midfoot and elevation of the medial longitudinal arch through its broad insertion on the navicular, cuneiforms, medial 3 metatarsal bases, and cuboid.

The posterior tibial tendon also indirectly affects hindfoot inversion due to its course running behind the medial malleolus and its close association with the deep deltoid and spring ligaments. With hindfoot inversion, the axes of the talonavicular and calcaneocuboid joints diverge, and the transverse tarsal joint (Chopart joint) becomes locked, which transforms the foot into a rigid lever.

Loss of posterior tibial function due to stretching or rupture of the tendon removes the primary inverter of the foot and leaves the primary and secondary everters of the foot, the peroneus brevis and longus, relatively unopposed. Therefore, posterior tibial dysfunction leads to flattening of the medial longitudinal arch, forefoot abduction, and hindfoot valgus. During the late stance phase of gait, the patient loses push-off strength due to inability to invert the hindfoot and achieve forefoot rigidity. With loss of the posterior tibial tendon function, the powerful gastrocsoleus complex acts at the talonavicular joint instead of at the level of the metatarsal heads.

The talar head is then pushed downward and medially, stretching the calcaneonavicular (spring) ligament. Continued weight bearing on the medial side of the heel eventually leads to deltoid ligament insufficiency and valgus instability of the ankle. Three-dimensional CT analysis of patients with acquired flatfoot has documented subluxation of the subtalar joint with less contact between all 3 facets of the calcaneus and talus compared to controls.

Clinical

The patient with posterior tibial tendon dysfunction initially complains of pain and swelling in the medial ankle and midfoot during weight bearing. Over time, the patient may notice loss of the arch and the tendency to walk on the inner border of the foot. Loss of push-off strength during gait occurs, and the patient may develop a limp. As the patient's heel displaces into valgus and the forefoot abducts, pressure between the calcaneus and fibula may develop, causing painful impingement between the lateral ankle and calcaneus. Abnormal wear of the medial heel and inner border of shoe wear may also be noted.

The patient is first examined while standing, allowing comparison of the symptomatic to the asymptomatic foot. Arch height is assessed and compared to the asymptomatic foot. In later stages of posterior tibial tendon dysfunction, the arch is lowered and the forefoot abducted. Viewing the patient's foot from behind allows the examiner to evaluate forefoot abduction and heel valgus. The toes visible lateral to the heel are counted. The finding of 1 or 2 toes visible lateral to the heel is normal. In cases of significant forefoot abduction, 3 or more toes are visible. This too-many-toes sign is a test to confirm forefoot abduction (see Image 1).

The angle that the heel forms with the longitudinal axis of the lower leg also should be measured. This posterior tibiocalcaneal angle is increased in cases of significant heel valgus. The patient should then be asked to stand on 1 foot and rise up on the toes. The patient usually needs to hold on to the examining table or wall for balance during this maneuver. Normally, the heel inverts as the posterior tibial muscle contracts and as the gastrocsoleus fires. In cases of posterior tibial tendon dysfunction, the heel does not invert, and the patient finds this single-limb heel rise maneuver painful, difficult, or impossible (see Image 2).

The patient then is examined seated on the examining table, and the course of the posterior tibial tendon is palpated for tenderness. Swelling along the posterior tibial tendon heath may be noted, and fluid may be palpated within the sheath. Posterior tibial strength is tested by holding the forefoot in a position of plantar flexion and eversion and asking the patient to invert the foot. During this maneuver, the posterior tibial tendon should be palpated to assess its continuity. The sinus tarsi and distal fibular area also should be palpated for tenderness because in later stages of posterior tibial tendon dysfunction, these areas of impingement may also be painful. The knee is extended, the foot is held in a subtalar neutral position, and passive ankle dorsiflexion is measured.

Usually, 10-20° of dorsiflexion is possible, but in cases of long-standing pes planus, dorsiflexion past neutral is often limited because of the development of a plantar flexion contracture. During the final stages of posterior tibial tendon dysfunction, the subtalar joint may be fixed in eversion, and inversion to neutral may be impossible. Finally, forefoot flexibility is assessed by pronating and supinating the forefoot while holding the heel in neutral position. Although the subtalar joint may be flexible, the transverse tarsal joint may have become fixed in varus, preventing plantigrade positioning of the forefoot (see Image 3). This finding has important implications for surgical treatment.

INDICATIONS

Section 3 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

Indications for treatment of posterior tibial tendon dysfunction are disabling pain, deformity, shoe wear problems, and difficulty with ambulation. A painless deformity that can be accommodated by normal footwear and allows for normal gait does not require treatment.

RELEVANT ANATOMY

Section 4 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

See Pathophysiology for relevant anatomy.

CONTRAINDICATIONS

Section 5 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

Contraindications to surgical treatment are active or chronic infection, open ulceration, and severe peripheral vascular disease. A relative contraindication to surgical treatment is peripheral neuropathy with loss of protective sensation.

WORKUP

Section 6 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

Lab Studies

• Generally, no laboratory studies are warranted for adult acquired flatfoot unless a systemic metabolic or inflammatory condition is suspected.
• A painless, atraumatic flatfoot deformity in an insensate foot is most likely due to neuroarthropathy (Charcot foot). The most common cause of neuroarthropathy in the United States is diabetes. If diabetes mellitus is not already diagnosed, a fasting blood glucose test is indicated.
• If the patient has pain in multiple joints, consider a workup for rheumatoid arthritis or seronegative spondyloarthropathy with rheumatoid factor, erythrocyte sedimentation rate, and HLA-B27.

Imaging Studies

• Radiography
• • Standing anteroposterior and lateral radiographs of the foot and ankle should be obtained.
  • Measurements of the lateral first talometatarsal angle, calcaneal pitch, distance from medial cuneiform base to the floor, and talonavicular coverage angle are made.
  • As a flatfoot deformity develops, the arch sags at the naviculocuneiform or talonavicular joint, causing a decrease in calcaneal pitch, a decreased lateral first talometatarsal angle, and depression of medial cuneiform height (see Image 4).
  • The forefoot moves laterally into abduction, causing lateral subluxation of the talonavicular joint and an increase in the talonavicular coverage angle (see Image 5).
  • Standing ankle views are mandatory to exclude ankle valgus instability as a contributing factor to the heel valgus and pes planus deformity.
• Tenography
• • Tenography has been used to diagnose posterior tibial tendon rupture with limited success.
  • For this test, 5 mL of radiopaque dye is injected into the sheath between the medial malleolus and navicular tuberosity. In later stages of dysfunction, the tendon and sheath become adherent, and injection of dye becomes impossible. Following tendon rupture, the sheath often is not palpable, and injection is very difficult.
  • In 1 study, tenography was successfully performed in only 1 of 6 patients.
• Magnetic resonance imaging
• • MRI is helpful in diagnosing posterior tibial tendon dysfunction, but it is not required to make the diagnosis.
  • Conti et al used MRI to describe 3 types of posterior tibial tendon degeneration. A type I finding is a partially torn tendon with tendon enlargement and vertical splits. Type II is a partially torn attenuated tendon. A type III finding is a complete rupture with a tendon gap.
  • Although it is sensitive, MRI can cause overestimation of the degree of tendon degeneration based on surgical findings, with a mere 40% correlation between MRI and surgical findings. This MRI classification is useful in predicting the outcome of tendon transfer, with higher grades of tendon degeneration faring worse than mild grades of degeneration.

Staging

Johnson and Strom described 4 stages of posterior tibial tendon dysfunction. These stages are used to dictate treatment.

• Stage 1 is characterized by peritendinitis and tendon degeneration, but the tendon length remains normal. This stage presents clinically as pain and swelling along the posterior tibial tendon sheath.
• In Stage 2, the posterior tibial tendon elongates, and a supple flat foot deformity develops. Although deformed on weight bearing, the hindfoot and midfoot deformities are passively correctable to neutral.
• Stage 3 occurs over time as the hindfoot becomes rigid in a valgus position, and the patient develops a rigid flatfoot deformity.
• Stage 4 develops as the deltoid ligament becomes incompetent and the talus tilts into valgus within the ankle mortise.

TREATMENT

Section 7 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

Medical therapy

Medical or nonoperative therapy for posterior tibial tendon dysfunction involves rest, immobilization, nonsteroidal anti-inflammatory medication, physical therapy, orthotics, and bracing. This treatment is especially attractive for patients who are elderly who place low demands on the tendon and who may have underlying medical problems that may preclude operative intervention.

During stage 1 posterior tibial tendon dysfunction, pain, rather than deformity, predominates. Cast immobilization is indicated for acute tenosynovitis of the posterior tibial tendon or for patients whose main presenting feature is chronic pain along the tendon sheath. A well-molded short leg walking cast or removable cast boot should be used for 6-8 weeks.

Weight bearing is permitted if the patient is able to ambulate without pain. If improvement is noted, the patient then may be placed in custom full-length semirigid orthotics. The patient may then be referred to physical therapy for stretching of the Achilles tendon and strengthening of the posterior tibial tendon. Steroid injection into the posterior tibial tendon sheath is not recommended due to the possibility of causing a tendon rupture.

In stage 2 dysfunction, a painful flexible deformity develops, and more control of hindfoot motion is required. In these cases, a rigid University of California at Berkley (UCBL) orthosis or short articulated ankle-foot orthosis (AFO) is indicated.

Once a rigid flatfoot deformity develops, as in stage 3 or 4, bracing is extended above the ankle with a molded AFO, double upright brace, or patellar-tendon-bearing brace. The goals of this treatment are to accommodate the deformity, prevent or slow further collapse, and improve walking ability by transferring load to the proximal leg away from the collapsed medial midfoot and heel.

Nonoperative therapy for posterior tibial tendon dysfunction has been shown to yield 67% good-to-excellent results in 49 patients with stage 2 and 3 deformities. A rigid UCBL orthosis with a medial forefoot post was used in nonobese patients with flexible heel deformities correctible to neutral and less than 10° of forefoot varus. A molded ankle foot orthosis was used in obese patients with fixed deformity and forefoot varus greater than 10°. Average length of orthotic use was 15 months. Four patients ultimately elected to have surgery. The authors concluded that orthotic management is successful in older low-demand patients and that surgical treatment can be reserved for those patients who fail nonoperative treatment.

The following is a summary of conservative treatments for acquired flatfoot:

• Stage 1 - NSAIDs and short-leg walking cast or walker boot for 6-8 weeks; full-length semirigid custom molded orthosis, physical therapy
• Stage 2 - UCBL orthosis or short articulated ankle orthosis
• Stage 3 - Molded AFO, double-upright brace, or patellar tendon–bearing brace
• Stage 4 - Molded AFO, double-upright brace, or patellar tendon–bearing brace

Surgical therapy

Surgical treatment of stage 1 dysfunction

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.

Surgical treatment of stage 2 dysfunction

Treatment of the flexible deformity of stage 2 posterior tibial tendon dysfunction is controversial. Direct repair of the torn tendon, tendon transfer or tenodesis by using the flexor digitorum longus (FDL) or flexor hallucis longus (FHL), spring ligament repair, medial displacement calcaneal osteotomy, lateral column lengthening, and limited arthrodeses of the hindfoot or midfoot have all been reported to yield satisfactory outcomes. Achilles tendon lengthening is recommended if ankle dorsiflexion is limited to 10° or less. The difficulty in obtaining an excellent surgical result is evidenced by the multitude of surgical procedures proposed for stage 2 dysfunction.

Direct repair

The torn tendon may be directly repaired by suturing the ends of an acute rupture. If the tendon is avulsed distally, it can be repaired to the navicular, or the portion of the tendon that is attenuated can be excised and the proximal and distal tendon stumps repaired end to end.

Proximal Z-lengthening of the posterior tibial tendon may be needed to achieve direct repair. The distal half of the anterior tibial tendon can be detached proximally and left attached to its insertion into the base of the first metatarsal and used to reinforce the directly repaired tendon.

Tendon transfer with FDL or FHL

The posterior tibial tendon often has an irreparable gap or is attenuated and scarred to the tendon sheath. The posterior tibial muscle may function poorly, even if the tendon can be directly repaired. This has led several authors to recommend tendon transfer to substitute for the dysfunctional or irreparable posterior tibial tendon. Jahss reported side-to-side tenodesis of the proximal and distal stumps of the posterior tibial tendon to the intact FDL tendon in five patients, reporting short-term satisfactory results, although all patients had residual heel valgus.

Transfer of the FDL tendon to the distal stump of the posterior tibial tendon or directly into the navicular tuberosity through a vertically oriented tunnel has been advocated by several authors with good short-term subjective results. The procedure uniformly failed to correct the flatfoot deformity but functioned well in relieving pain and improving inversion strength.

Some authors have emphasized the importance of spring ligament (calcaneonavicular ligament) repair or reconstruction in conjunction with FDL transfer. A retrospective study of spring ligament repair/reconstruction and FDL transfer demonstrated excellent functional results in 14 of 18 patients, although arch correction on radiographs was inconsistent.

Goldner et al reported using the FHL for transfer into the distal stump of the posterior tibial tendon in 2 patients, 1 had a previous laceration of the tendon and the other had a chronic tear. The younger patient had a full and complete recovery, and the outcome in the other patient was not reported.

Calcaneal osteotomy

Follow-up examination of patients who have undergone FDL tenodesis or transfer alone has not shown consistent correction of deformity. Because of a concern of deteriorating clinical results over time with soft tissue procedures alone, some surgeons added bony procedures to the soft tissue reconstruction. They theorized that the restoration of arch height and heel position might produce more durable and improved clinical results. The ideal bony procedure to treat acquired pes planovalgus corrects the foot deformity, decreases strain on the spring and deltoid ligaments, and protects the soft tissue reconstruction.

Gleich first described a medial and inferior displacement osteotomy of the posterior third of the calcaneus in 1893. Koutsogiannis first described the medial displacement calcaneal osteotomy as a treatment of valgus hindfoot deformity. The addition of a medial displacement osteotomy through the posterior portion of the calcaneus moves the valgus heel under the weight-bearing axis of the leg. The osteotomy also decreases the heel valgus producing deforming force of the Achilles tendon by shifting the Achilles insertion medially. In vitro studies have shown that a 1-cm medializing osteotomy of the calcaneal tuberosity decreases strain on the spring ligament and deltoid ligament. A 1-cm translational calcaneal osteotomy actually moves the center of pressure in the ankle joint 1.58 mm medially.

A retrospective study of 32 patients undergoing FDL transfer and calcaneal osteotomy with an average of 20 months follow-up showed 94% pain relief, improved function, and significant improvement in radiographic arch measurements. Sammarco and Hockenbury reported satisfactory results in 19 patients undergoing FHL transfer and medial displacement calcaneal osteotomy. Despite the fact that the FHL is stronger than the FDL, postoperative radiographs did not show significant arch correction, indicating that a medial soft tissue procedure in conjunction with calcaneal osteotomy may not result in arch correction.

Lateral column lengthening

The Evan anterior calcaneal lengthening osteotomy lengthens the lateral column of the foot by inserting a 10- to 15-mm bone graft 10-15 mm proximal to the calcaneocuboid joint. This lateral column-lengthening procedure radiographically improves forefoot abduction and hindfoot valgus and restores the medial longitudinal arch. Cadaveric studies show that lateral column lengthening protects the calcaneonavicular (spring) ligament form overload during weight bearing. A retrospective study of 19 patients undergoing Evan calcaneal osteotomy in conjunction with posterior tibial tendon repair or shortening and deltoid ligament repair or reconstruction reported six excellent, 11 good, and 2 fair results. Significant radiographic arch correction was noted at 23-month follow-up.

A cadaver study of Evan calcaneal lateral column lengthening in normal feet showed elevated calcaneocuboid joint pressures following the procedure, raising questions about potential long-term degenerative arthritis of the calcaneocuboid joint following the procedure. This concern has led to the recommendation of lengthening the lateral column through distraction arthrodesis of the calcaneocuboid joint. However, results of another cadaver study failed to confirm elevation of calcaneocuboid joint pressure following calcaneal Evans osteotomy in preexisting flatfeet and, in some cases, actually showed lowering of calcaneocuboid pressure after lateral column lengthening.

A retrospective study of 41 feet undergoing lateral column lengthening through distraction arthrodesis of the calcaneocuboid joint in conjunction with FDL transfer and selective medial midfoot arthrodesis found satisfactory outcomes in 85% of cases and a uniform radiographic correction of flatfoot, but a calcaneocuboid nonunion rate of 20% was found. Note that this series included several patients who also had fusions of the naviculocuneiform or first metatarsocuneiform joints and that distraction arthrodesis of the calcaneocuboid joint was not the only bony procedure performed.

Thomas et al reported on 25 patients who underwent FDL transfer to the navicular and lateral column lengthening using 2 different methods. Postoperative American Orthopedic Foot and Ankle Society (AOFAS) scores were 87.9 for the osteotomy group and 80.9 for the calcaneocuboid distraction arthrodesis group, but the difference was not statistically significant. Significant improvement in radiographic parameters was seen in both groups. Complication rates were high in both groups, with an especially high rate of nonunion and delayed union in the calcaneocuboid distraction group.

A combination of FDL transfer to medial cuneiform, medial displacement calcaneal osteotomy, and Evans lateral column lengthening has produced good short-term results in a retrospective study of 17 patients with stage 2 posterior tibial tendon dysfunction. Significant improvement in the AOFAS hindfoot score was seen, and radiographs showed significant improvement in arch measurements at 17.5-month follow-up.

Fusion

The difficulty with achieving consistent lasting correction of the flatfoot deformity with soft tissue procedures alone or in conjunction with osteotomies has led some surgeons to recommend fusion as a treatment of stage 2 deformity. Some surgeons feel that soft tissue procedures are less successful in patients who are obese and that obesity is an indication for joint fusion.

Kitaoka et al compared subtalar arthrodesis versus FDL transfer in an in vitro study of flatfooted specimens and found a more consistent correction of deformity following subtalar arthrodesis. A retrospective study of 21 feet treated with subtalar arthrodesis for posterior tibial tendon dysfunction yielded good-to-excellent results in 16 of 21 feet and significant correction of flatfoot deformity based on radiographic measurements. Stephens et al emphasize the need for reducing the subtalar joint prior to fusion and for differentiating a subtalar repositional arthrodesis from a subtalar fusion in situ.

Another in vitro study compared subtalar fusion alone, calcaneocuboid fusion alone, talonavicular fusion alone, double (talonavicular and calcaneocuboid) arthrodesis, and triple arthrodesis in their abilities to correct an experimentally corrected flatfoot deformity. The study found that talonavicular or double arthrodesis resulted in better correction of flatfoot deformity than did subtalar fusion alone. A retrospective study of 29 patients with posterior tibial tendon dysfunction treated with isolated talonavicular fusion found good-to-excellent results in 86% of patients at an average follow-up of 26 months.

Combination treatments

Johnson et al used subtalar fusion, FDL transfer, and spring ligament repair in 17 feet with stage 2 dysfunction. At an average follow-up of 27 months, they reported excellent radiographic correction of pes planus deformity and improvement in AOFAS hindfoot score.

Chi et al reported on 65 feet that underwent FDL transfer with lateral column lengthening and/or medial column fusion. Lateral column fusion was performed for calcaneovalgus deformity with a flat calcaneal pitch angle. If the naviculocuneiform or first metatarsocuneiform joint showed sag on lateral radiographs, they also were fused. At 1- to 4-year follow-up, 88% of the feet that underwent lateral column lengthening, 80% of the feet that had medial column stabilization, and 88% that had medial and lateral procedures had decreased pain or were pain-free. Significant radiographic correction of the pes planus deformity was seen in all groups. The authors concluded that fusion of these unessential joints effectively corrected deformity and relieved pain.

Surgical treatment of stage 3 dysfunction

Surgical treatment of stage 3 posterior tibial tendon dysfunction requires realignment and arthrodesis of rigidly malaligned joints. The principle of fusing the fewest number of joints possible should be followed. Over time, the subtalar joint becomes fixed in valgus, and a subtalar arthrodesis is indicated to realign the hindfoot. If the forefoot is fixed in varus at the transverse tarsal (Chopart) joint or degenerative changes are present in the talonavicular and calcaneocuboid joints, fusion of these joints should be added. Stage 3 posterior tibial tendon dysfunction with fixed forefoot varus is treated with triple arthrodesis.

Surgical treatment of stage 4 dysfunction

The valgus ankle in stage 4 dysfunction develops due to deltoid ligament instability. The deltoid ligament is difficult to reconstruct with a tendon transfer. Arthritic valgus ankle deformities secondary to deltoid ligament insufficiency have not been successfully treated with a total ankle arthroplasty due to the inability to achieve ligamentous balance. Treatment of a fixed subtalar deformity and degenerative ankle valgus requires tibiotalocalcaneal fusion. If fixed forefoot varus is also present, pantalar fusion may be necessary to adequately realign the foot. Either tibiotalocalcaneal or pantalar fusion results in a stiff foot, which results in an altered gait. Shoe modifications and bracing are often required after surgery.

The following is a summary of surgical treatments for acquired flatfoot:

• Stage 1 - Tenosynovectomy, tendon debridement, and tendon repair of partial tears
• Stage 2 (add Achilles tendon lengthening or gastrocnemius recession in cases of equinus contracture)
  • PTT repair
  • FDL or FHL transfer alone
  • FDL or FHL transfer and calcaneal osteotomy
  • FDL transfer and lateral column lengthening
  • FDL transfer, lateral column lengthening, and medial column fusion
  • FDL transfer, lateral column lengthening, and calcaneal osteotomy
  • Subtalar fusion
  • Talonavicular fusion
• Stage 3
  • Subtalar fusion
  • Triple arthrodesis
• Stage 4
  • Tibiotalocalcaneal fusion
  • Pantalar fusion

Preoperative details

The stage of the disease, the overall medical condition of the patient, and the patient's expectations determine the recommended treatment. If the patient has low physical demands or has serious underlying medical problems, he/she should be treated nonoperatively. Patients should be advised about the prolonged length of recovery following surgical reconstruction of the foot. Generally, 6 weeks of no weight bearing is required for soft tissue procedures and osteotomies, and up to 3 months of no weight bearing is required for fusions. Swelling of the foot should be expected for 4-10 months after surgery. Finally, although most surgical procedures report a high incidence of good-to-excellent results postoperatively, many patients continue to have some foot discomfort with prolonged standing or walking.

Intraoperative details

FHL transfer

An 8-cm incision is made along the course of the posterior tibial tendon from a point just proximal and posterior to the medial malleolus to the navicular tuberosity. The posterior tibial tendon sheath is opened and a tenosynovectomy is performed. Partial tears of the tendon are repaired with 2-0 nonabsorbable Dacron sutures. If the tendon is attenuated and irreparable, it is excised, leaving a 1-cm stump attached to the navicular tuberosity. If the spring ligament is torn or attenuated, it is repaired and imbricated with 2-0 nonabsorbable sutures. The FDL tendon is identified in its sheath just deep to the posterior tibial tendon sheath. The FHL tendon is identified deep to the sustentaculum tali. The FHL tendon is sutured to the FDL tendon distally with 2-0 nonabsorbable sutures and then divided proximal to the anastomosis (see Image 6).

A suture anchor is placed in the navicular tuberosity, and the transferred FHL tendon is sutured to the navicular and to the distal stump of the posterior tibial tendon with number 2 nonabsorbable sutures (see Image 7). Tension on the FHL tendon is adjusted with the foot in inversion and plantarflexion. The tendon sheath, subcutaneous tissue, and skin are closed in layers. Percutaneous triple-cut Achilles tendon-lengthening or gastrocnemius recession is performed if the foot cannot be easily dorsiflexed past neutral.

After surgery, the foot is placed in a posterior splint in a position of equinus and inversion. A short-leg non–weight-bearing cast is applied 3 days after surgery to maintain the position of equinus and inversion, and is worn for 4 weeks. The foot then is placed in a short-leg walking cast in a neutral position, which is worn for an additional 2 weeks. A Cam walker boot is worn beginning 6 weeks postoperatively and is removed for range of motion and strengthening exercise. Immobilization is discontinued 10 weeks postoperatively.

FDL tendon transfer

A similar approach is used for the FDL tendon transfer. In this case, the distal FDL is sutured into the FHL, and the FDL is released just proximal to the suture to give adequate length to the tendon. A vertical hole then is drilled into the navicular bone. The surgeon should be careful to leave an adequate bridge of bone in place medially. The plantar hole is rounded smooth proximally to take any sharp edge away that may damage the tendon. With the aid of a suture passer, the FDL tendon is routed from plantar to dorsal and sutured to itself (if enough tendon length is available) and to the surrounding tissue. The foot is held in an inverted position during this maneuver to place appropriate tension on the FDL tendon. Closure and postoperative care are similar to those for FHL transfer.

Calcaneal osteotomy

Calcaneal osteotomy is used in conjunction with FDL or FHL transfer. The calcaneal osteotomy is performed prior to the tendon transfer. A 5-cm oblique incision is made along the lateral heel from posterosuperior to anteroinferior. The incision is made posterior to the peroneal tendon sheath and sural nerve (see Image 8). Sharp dissection is used to proceed directly down to bone. Skin flaps are kept thick. The lateral wall of the calcaneus is exposed subperiosteally using a Key elevator. Small Hohmann retractors are placed over the superior aspect of the calcaneus anterior to the Achilles tendon and at the plantar aspect of the calcaneus anterior to the plantar fascial attachment.

A straight, wide power osteotome (Micro-Aire, Inc) or sagittal saw is used to make a cut across the calcaneus in line with the incision at a 45° angle to the plantar surface of the foot and perpendicular to the surface of the calcaneus. C-arm fluoroscopy is used to document proper osteotomy position prior to making the bone cut. The medial aspect of the heel is palpated to gauge the depth of the osteotomy and to avoid overpenetration of the osteotome, which could cause injury to the tibial nerve and vessels. The depth of the osteotome cut also can be judged with a freer elevator during completion of the cut. After completion of the osteotomy, the medial soft tissues are spread by inserting a large Key elevator into the osteotomy site and levering the calcaneal tuberosity downward. A laminar spreader also can be placed into the osteotomy site and used to spread the medial soft tissues (see Image 9).

The tuberosity should be easily translated medially 1 cm if the medial soft tissues are adequately mobilized. It is important to ensure that the plantar surface of the osteotomy has been adequately mobilized. Otherwise, the posterior calcaneal fragment rotates internally rather than slide medially. The calcaneal tuberosity then is translated 1 cm medially, while avoiding superior translation of the fragment. A surgical assistant then holds the osteotomy in a corrected position while it is fixated with 2 4.0-mm diameter partially threaded cancellous screws placed perpendicular to the osteotomy cut (see Image 10). Typically, no washers are used.

Avoid placement of the screws into the subtalar joint and keep the screw heads off of the weight-bearing surface of the heel. Screws are placed in a parallel fashion. Because the tuberosity has been shifted medially, the screws should be aimed slightly laterally in order to hit the main calcaneal body or the screw(s) may miss the anterior calcaneus. Screw position is documented with intraoperative fluoroscopy (see Image 11).

The wound is closed in layers. Postoperative care is the same as for FDL transfer, except weightbearing is not allowed until radiographs indicate that the osteotomy has healed, usually 6-8 weeks postoperatively.

Lateral column lengthening by distraction arthrodesis of the calcaneocuboid joint

Lateral column lengthening by distraction arthrodesis of the calcaneocuboid joint is also performed in conjunction with FDL or FHL transfer. A 5-cm dorsolateral incision is made over the calcaneocuboid joint. The sural nerve and peroneal tendons are retracted plantarly. The joint is exposed, and the articular cartilage is removed with osteotomes and curettes. The joint then is distracted using a smooth laminar spreader. An alternative technique is to use a small joint external fixator (EBI) to distract the lateral column, placing pins in the cuboid and calcaneus. Correction of the medial longitudinal arch and correction of heel valgus to neutral or slight valgus serve as the endpoint for distraction. The forefoot also should be rotated into neutral position prior to graft insertion.

A trapezoidal tricortical iliac crest graft then is fashioned to fit the distracted joint. The bone graft should be wider both dorsally and laterally, and tapering towards the plantar and medial aspects, respectively. A graft width of 8-12 mm usually suffices (see Images 12-13). A cervical plate placed laterally with 2 screws in the calcaneus and 2 screws in the cuboid is used for fixation. The remainder of the calcaneocuboid joint is filled with cancellous graft. The postoperative course is the same as for the calcaneal osteotomy, except weight bearing is delayed until fusion is confirmed radiographically.

Follow-up

For excellent patient education resources, visit eMedicine's Foot, Ankle, Knee, and Hip Center. Also, see eMedicine's patient education articles Ankle Sprain and Sprains and Strains.

COMPLICATIONS

Section 8 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

The major concern with any foot reconstructive procedure is to achieve a painless plantigrade foot that fits into a shoe. Undercorrection or overcorrection of a deformity can easily occur. Soft tissue procedures alone do not correct the pes planus deformity of posterior tibial tendon insufficiency. Use caution intraoperatively to ensure that the heel is in slight valgus and that the forefoot is plantigrade and not left in varus. An ankle equinus contracture should not be left untreated.

As with any medial midfoot procedure, take care to avoid neurovascular injury during posterior tibial tendon debridement or tendon transfer. Many surgical techniques involve suturing the distal stump of the transferred FDL tendon to the adjacent FHL tendon at the knot of Henry. The neurovascular bundle is at significant risk due to its close proximity during this anastomosis. Medial skin flaps should be kept thick to avoid wound dehiscence.

During medial displacement calcaneal osteotomy, the sural nerve is at risk if the lateral incision is made too anteriorly. The calcaneal osteotomy is made at a 45° angle to the long axis of the calcaneus through the calcaneal tuberosity. If the osteotomy is made too anteriorly, the posterior facet of the subtalar joint could be damaged. If the osteotomy is made too posteriorly, the Achilles insertion could be disrupted. If the osteotome overpenetrates the medial calcaneal wall, the neurovascular bundle could be damaged.

Avoid superior translation of the tuberosity during medial translation of the posterior calcaneal tuberosity, or the calcaneal pitch could be decreased and the arch flattened further. Two screws are recommended for fixation of the calcaneal osteotomy to avoid rotation of the calcaneal fragment and to enhance fixation, although single large cancellous screws have been used successfully. The screws should be inserted perpendicular to the osteotomy plane, and the subtalar joint should not be penetrated.

The lateral column-lengthening procedure achieves arch correction both clinically and radiographically. Overlengthening of the lateral column is possible, with creation of painful lateral forefoot overload. The Evans calcaneal osteotomy places the sural nerve, peroneal tendons, and anterior and middle subtalar facets at risk. The optimal position of the calcaneal osteotomy is 10 mm proximal to the calcaneocuboid joint to avoid damage to the anterior and middle facets. The high rate of calcaneocuboid joint nonunion during calcaneocuboid distraction arthrodesis also is a concern.

OUTCOME AND PROGNOSIS

Section 9 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

See Treatment, Surgical therapy for outcomes of various surgical procedures.

FUTURE AND CONTROVERSIES

Section 10 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

Treatment of stage 1 posterior tibial tendon dysfunction is straightforward. The goal is to halt the progression of tenosynovitis through conservative or operative methods in order to prevent tendon rupture. The rigid deformities of stages 3 and 4 require operative correction and fusion of the involved joints in order to produce a plantigrade balanced foot. The principle of fusing the fewest number of joints possible should be followed.

Surgical treatment of stage 2 posterior tibial tendon dysfunction generates the most controversy among foot and ankle surgeons. Many different surgical procedures have demonstrated good short-term relief of pain and improved function but limited ability to correct deformity. A tendon transfer using FDL or FHL tendon yields satisfactory short-term pain relief, but arch correction is not achieved. The addition of a medial displacement calcaneal osteotomy improves heel valgus position but may not produce complete correction of the medial longitudinal arch. A lateral column-lengthening procedure through the anterior calcaneus or through the calcaneocuboid joint achieves arch correction, but it requires iliac crest tricortical graft and risks nonunion or overcorrection.

In patients who are large or obese, subtalar or talonavicular fusion may be needed to achieve long-term correction, although these procedures limit hindfoot motion significantly. Perhaps the most biomechanically sound surgical treatments are those using tendon transfer to substitute for the deficient posterior tibial tendon, with lateral column lengthening to restore alignment of the subtalar and talonavicular joints and medial fusion of the sagging naviculocuneiform joint or first metatarsocuneiform joint. These procedures require multiple steps, multiple incisions, and prolonged recovery time. Perhaps the most important unanswered question is whether arch correction is required to achieve a long-term satisfactory outcome.

MULTIMEDIA

Section 11 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

Media file 1:  Too-many-toes sign. Three lateral toes are visible on the symptomatic left foot compared to only 2 toes on the right foot (black arrow). The medial midfoot is prominent and swollen (yellow arrow).
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Media file 2:  Single-limb heel rise. A patient with posterior tibial tendon dysfunction is unable to rise up on the toes because of an inability to invert the hindfoot.
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Media file 3:  Fixed forefoot varus is characterized by elevation of the medial side of the forefoot, even after the heel is placed in a neutral position.
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Media file 4:  Standing lateral radiograph of the foot of a patient with posterior tibial tendon (PTT) dysfunction. A, Lateral first talometatarsal angle (normal value 0°). B, Calcaneal pitch (normal value, 20-25°). C, Distance from medial cuneiform to floor (normal value varies with foot size). As deformity increases secondary to posterior tibial tendon dysfunction, the talus plantarflexes and the medial border of the foot is lowered. Therefore, the lateral first talometatarsal angle decreases, the calcaneal pitch decreases, and the medial cuneiform is depressed closer to the floor.
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Media file 5:  Standing anteroposterior radiograph of a patient with posterior tibial tendon (PTT) dysfunction shows the talonavicular coverage angle; the navicular axis is formed by a perpendicular to a line connecting the medial and lateral aspects of the navicular proximal articular surface. The talonavicular coverage angle is formed by the talar and navicular axes. As forefoot abduction increases, the talonavicular coverage angle increases.
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Media type:  X-RAY

Media file 6:  The flexor hallucis longus (FHL) tendon is identified under the sustentaculum tali and is pulled proximally. The FHL and flexor digitorum longus (FDL) tendons then are sutured to each other with 2-0 nonabsorbable suture prior to division of the FHL tendon.
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Media file 7:  The flexor hallucis longus (FHL) tendon is rerouted anterior to the posterior tibial tendon (PTT) and sutured to the navicular tuberosity using a suture anchor. Multiple number 2 nonabsorbable sutures also are used to suture the FHL tendon to the PTT stump and navicular tuberosity periosteum.
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Media file 8:  The incision for calcaneal osteotomy is made posterior to the peroneal tendon sheath and sural nerve. The incision is made at a 45° angle to the plantar aspect of the foot.
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Media file 9:  The calcaneal osteotomy is distracted with a laminar spreader to spread the medial soft tissues. This permits easy medial displacement of the calcaneal tuberosity.
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Media file 10:  Lateral radiograph of the fixated calcaneal osteotomy. After the tuberosity is displaced medially 1 cm, 2 screws are inserted perpendicular to the osteotomy site under fluoroscopic control.
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Media file 11:  Intraoperative axial view of the fixated calcaneus documents satisfactory medial translation of the tuberosity and satisfactory screw position.
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Media file 12:  Preoperative anteroposterior view of foot prior to lateral column lengthening. Note forefoot abduction and increased talonavicular coverage angle.
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Media file 13:  Distraction arthrodesis of the calcaneocuboid joint with tricortical iliac crest graft results in lengthening of the lateral column. The osteotomy is fixated with a laterally placed cervical plate. Note correction of forefoot abduction and correction of the talonavicular coverage angle.
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Media type:  Image

REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• Multimedia
• References

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Article Last Updated: Jun 1, 2005