The majority of posterior tibial tendon dysfunction patients will demonstrate medial ankle and foot pain, especially in the early stages of the disease. At later stages, lateral pain can be seen as well, due to sub-fibular impingement or peroneal tendon injury.[10] A thorough physical examination can help to determine the grading and severity of the disease. Attention should first be turned to the gross inspection of the feet while standing. A weight-bearing examination is of importance as a flexible deformity may present normally, while the patient is non-weight bearing. The medial longitudinal arch collapse leads to pes planus, an easily visualized condition. While inspecting the patient, one will also commonly see a “too many toes” sign, which is visible when looking from behind the patient. Due to the valgus alignment of the foot, you will see flaring out of more than two toes from the lateral hindfoot. Equinus contracture is also a common finding, which can limit ankle dorsiflexion.

Single-limb heel raise is an important clinical test that can differentiate stage 1 disease from stage 2 and higher. A patient in stage 1 disease should be able to perform this test without pain. In stage 2 disease, patients may be able to perform the test but will likely have pain. In later stages, the rigid deformity may prevent the patient from completing the test. The flexibility of the foot also requires evaluation on an exam.[10]

Imaging is critical in determining the severity of disease and subsequent treatment. Anteroposterior (AP) and lateral radiographs are necessary. Increased talonavicular uncoverage and increased talo-first metatarsal angle (or Simmons angle) will present on the AP foot radiograph. The normal talo-first metatarsal angle is around 7 degrees, and angles over 16 degrees indicate flatfoot deformity.[11] The talonavicular coverage expresses itself as the amount of the talus that is not in contact with the navicular medially, with values over 30 to 40% typically indicated forefoot abduction seen in stage II-IV PTTD.[9] On the weight-bearing lateral radiograph, one should evaluate for increased talo-first metatarsal angle (or Meary angle) which normally measures 0 degrees +/- 4 degrees but typically measures over 20 degrees in flatfoot deformity.[10]

Treatment for posterior tibial tendon dysfunction is a complicated subject, so this review will attempt to simplify by each stage for the reader:

• All Stages initially:
  • Conservative management with NSAIDs and activity modification. Also meant for non-surgical candidates or low demand, elderly patients.[12]
• Stage 1:
  • Conservative management through immobilization in a walking boot or cast for up to 3 to 4 weeks to allow for healing of the posterior tibial tendon may be warranted followed eccentric strengthening with physical therapy.[1]
  • If immobilization and physical therapy are successful, transitioning into custom-molded orthotics or AFO is appropriate to maintain relief. Emphasis on medial forefoot posting is critical. University of California Biomechanics Laboratory (UCBL) orthoses are a form of a custom insert with a lace-up component that can help maintain midfoot height.[13]
  • Conservative therapy should be for 3 to 4 months, and if it fails, then surgical intervention may be warranted. A tenosynovectomy, with tubularization, may be indicated
• Stage 2A:
  • Conservative immobilization and physical therapy with orthotics or ankle-foot orthosis (AFO) as recommended in stage 1
  • Surgical treatment involves medial calcaneal osteotomy with posterior tendon debridement and repair. Ancillary procedures may include any or all of the following: flexor digitorum tendon (FDL) transfer, spring ligament reconstruction, or Achilles tendon lengthening.[14]
• Stage 2B:
  • All of the previously listed procedures in Stage 2A +/- lateral column lengthening, or isolated subtalar joint arthrodesis
• Stage 3:
  • Conservative therapies, as mentioned above.
  • Surgical treatment is often warranted as it involves rearfoot arthritic changes and a medial double arthrodesis or triple arthrodesis common (subtalar, calcaneocuboid, and talonavicular arthrodesis) is indicated with or without deltoid ligament repair.[15]
• Stage 4
  • Conservative therapies, as mentioned above.
  • Surgical treatment is often necessary as it involves arthritic changes in the ankle, as well as rearfoot. Surgical options include any combination of Triple arthrodesis with Achilles tendon lengthening, deltoid ligament reconstruction, and total ankle arthroplasty with replacement.[15] Medial double arthrodesis, deltoid ligament reconstruction, and total ankle arthroplasty with a replacement if ankle deformity is reducible. If the patient is a candidate for total ankle arthroplasty, then it is recommended to stage procedure by performing rearfoot arthrodesis and soft tissue balancing followed by a second stage 4 to 8 weeks later for total ankle arthroplasty 
  • Tibiotalocalcaneal (TTC) arthrodesis for rigid hindfoot with significant valgus alignment of the talus within the ankle mortise.[16][17]. Pantalar arthrodesis (triple arthrodesis with the addition of ankle arthrodesis).

Although posterior tibial tendon dysfunction is the most common cause of adult acquired flatfoot deformity, there are many other related conditions. Diagnoses listed below can present very similarly to PTTD and should merit consideration during evaluation [18]:

• Tarsal coalition
• Inflammatory arthritis
• Charcot arthropathy
• Neuromuscular disease
• Traumatic disruption of midfoot ligaments

Stage 1:

• Normal radiographs, able to perform single-heel raise, and mild tenosynovitis

Stage 2A:

• Arch collapse on a radiograph, unable to perform single-heel raise, and a flexible flatfoot deformity

Stage 2B[19]:

• Arch collapse and talonavicular uncoverage (over 40%) on a radiograph, unable to perform single heel raise, flexible flatfoot deformity, and characteristic forefoot abduction or “too many toes” sign

Stage 3:

• Subtalar arthritis on a radiograph, unable to perform single heel raise, flatfoot deformity with rigid forefoot abduction and hindfoot valgus

Stage 4 [19]:

• Valgus deformity of talus in the ankle mortise visualized on AP radiograph of the ankle - talar tilt due to deltoid ligament compromise, subtalar arthritis on radiographs, unable to perform single heel raise, flatfoot deformity with rigid forefoot abduction and hindfoot valgus

Posterior tibial tendon dysfunction is a progressive disorder that will continue to deteriorate without treatment. Early detection and intervention will help to slow progression. Patients provided with custom orthotics and rehabilitation have been shown to have significant improvement. In a recent study by Alvarez et al., about 89% of their patients with stage I and II PTTD responded to orthotics and PT. Nearly all of these patients were back to full strength by 4 months.[20] According to analyses of outcomes of surgical treatment, results are much less predictable, and a return to the pre-disease state should not be guaranteed. Patients may continue to have some residual effects after reconstructive surgeries.[21]

General complications include thromboembolic events, infection, wound dehiscence, neurologic injury, and/or painful hardware. Reports exist of wound healing complications in up to one-third of patients undergoing flatfoot reconstruction, so proper wound care is paramount.[22]

Postoperative care is crucial to the success of the procedures. Typically, patients will receive a type of non-weight bearing cast or splint for around 6 to 8 weeks. Followup should be between 10 to 14 days for suture removal evaluation. Physical therapy may be necessary for certain patients.

Patient education and emphasis of conservative approach can help patient outcomes: 

• Activity restriction and modification is a significant initial step in non-operative management.
• Evidence supports conservative therapy in the early stages of the disease, such as the use of non-steroidal anti-inflammatory drugs. 
• Providing prescriptions for medial arch support insoles or custom orthotics is necessary in many cases.
• Moreover, surgery is usually the last resort if recovery is prolonged.
• When performing surgery, temper patient expectations, as reconstruction options commonly have residual symptoms.

• Staging of posterior tibial tendon dysfunction is critical to surgical plan/outcome
• Difference between Stage 2 and 3 is the presence of rigid deformity
• Identification of the specific location of arthritic changes on radiograph will help to differentiate between stage 3 and 4 PTTD: Stage 3 demonstrates subtalar joint arthritis, Stage 4 demonstrates talar tilt and ankle arthritis

The importance of finding posterior tibial tendon dysfunction at early stages may prevent rapid deterioration with conservative measures. Primary care physicians and nurse practitioners may be able to refer patients to sub-specialists, such as foot and ankle orthopedic surgeons for a more thorough workup/evaluation, which can lead to significantly better patient outcomes. 

PTTD requires an interprofessional team approach, including physicians, specialists, specialty-trained nurses, and pharmacists, all collaborating across disciplines to achieve optimal patient results. [Level V]