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Differential diagnosis

Tibialis Posterior Tendon Dysfunction (Adult Acquired Flatfoot Deformity)

Testing tibialis posterior strength

Significant History/Physical symptoms

Posterior tibial tendon dysfunction (disorder or rupture) is a term that covers a constellation of signs and symptoms. It is increasingly referred to as adult acquired flatfoot deformity (AAF) as a diagnostic term because the condition is more complex and involved than simply a dysfunction of the tibialis posterior muscle and tendon. Conservative treatment is advocated early as mild deformity can progress rapidly and lead to increasing pain and loss of function for the patient.

Some evidence suggests the underlying mechanism for chronic TPTD is degenerative tendinosis rather than tendinitis.

Any disruption to the tibialis posterior tendon results in other ligaments becoming plastically deformed and a flatfoot can result. Also the force generated by the gastrocnemius and soleus muscles is reduced. Gait will therefore be adversely disrupted. The loss of strength of the tibialis posterior tendon can be sudden or gradual.

Radiographic evaluation is not required in order to make a diagnosis of dysfunction of the posterior tibial tendon, the diagnosis is based on clinical evaluation.

  • 3 times more common
  • ≥ 40 years old
  • pain location medial ankle/foot
  • aggravated by activity
  • patient recalls traumatic (often minor) event
  • difficulty walking on uneven ground
  Stage 1 Stage 2 Stage 3 Stage 4
Posterior tibial tendon Tenosynovitis, degeneration, or both Elongation and degeneration Elongation and degeneration Elongation and degeneration
Deformity Absent Flexible, reducible pes planovalgus deformity with hindfoot held in equinus Fixed, irreducible pes planovalgus deformity Fixed, irreducible pes planovalgus deformity
Pain Medial Medial, lateral, or both Medial, lateral, or both Medial, lateral, or both
Single limb heel-rise Mild weakness; hindfoot inverts normally Marked weakness; None or limited inversion of the hindfoot Unable to perform test; no inversion of hindfoot Unable to perform test; no inversion of hindfoot
Too many toes sign Negative Positive Positive Positive
Valgus deformity and arthritis of the ankle No No No Yes
Table showing the 4 stages of Posterior Tibial Tendon Dysfunction (PTTD), adapted from Johnson KA, Strom DE. Tibialis posterior tendon dysfunction. Clin Orthop 1989;239:197

Less Common Differential Diagnoses not included in this pathway:

  • Spring ligament strain / rupture
  • Tarsal coalition
  • Inflammatory arthritis
  • Charcot arthropathy
  • Neuromuscular disease

First line intervention

The first line intervention should focus on educating the patient about the condition, and prescribing therapies that can be self-administered by the patient. 

Leaflets should be given to patients to reinforce verbal advice and links to NHS website resources where available.

Guidance for treatment duration and escalation

First line Intervention should be given for 6-12 weeks, if the patient has not responded by then the clinician can proceed to the Second Line Intervention according to the escalation guidance.

lt is recommended that individuals are educated by their clinician with regards to the aetiology, pathological processes and predisposing biomechanical impairments associated with their condition.

A behavioural change plan is designed in collaboration, with the patient’s decision making informed by their clinician’s advice on mechanical unloading and adaptive reloading of the affected tendon.

Unloading is achieved by various means including activity limitation, orthotic wear and exercises such as stretching of short calf muscles.

This is followed by a period of controlled reloading which is achieved by such means as increased activity levels, weaning from unloading orthotic devices and strengthening exercises for the affected tendon.

Finally the prevention phase is recommended which can be viewed as a targeted continuation of prior education, unloading and reloading phases with special emphasis on the patient’s independence in self-management of residual symptoms and physical impairments.

In the initial stages exercises help to strengthen weak muscles and improve foot function.

Calf stretches are essential to the management of TPTD as the calf muscles tend to shorten when the medial arch starts to flatten. Orthoses help support and stabilise the foot and help prevent further damage, however, the exact mechanism of how orthoses work is not well researched. These strategies gave best results when used in combination and was the most effective initial treatment.

Initial Patient Directed Treatment Options

      • Advise weight loss if appropriate
      • Activity modification and management advice
      • Analgesia & Non-Steroidal Anti Inflammatory Drugs as appropriate.
      • PEACE and LOVE (Protect, Elevate, Avoid anti-inflammatory modalities, Compress, Educate, Load, Optimisation, Vascularisation and Exercise)
      • Footwear Advice
      • Exercise Prescription
        • Eccentric exercises ~ Stretches and strengthening exercises, eccentric exercises more effective than concentric.
      • Heel Raise
        • These should be given bilaterally so as to avoid Leg Length Discrepancy

Non evidenced treatments

The following treatments are not supported by high quality evidence therefore they should not be considered as a treatment option for patients unless all other evidenced treatments have been tried unsuccessfully and there is clear clinical justification as to why these treatments are being used.

  • Acupuncture
    • Insufficient evidence to support use in this condition
  • Low Level Laser Therapy LLLT
    • Some limited evidence but more research needed to determine optimum dosage to provide a significant effect
  • Therapeutic Ultrasound
    • Minimal benefit and no conclusion on effective dosage parameters 
  • Corticosteroid Injection

If a patient is not improving as expected they should be referred on to another AHP who can deliver an escalated evidenced intervention or referred to orthopaedics as per the escalation guidance on the pathway.

Second line intervention

(Stage 2)

  • Biomechanical assessment and prescription of Foot Orthosis
    • Address biomechanical deficit if indicated by assessment.
    • Off the shelf or custom made insoles should be prescribed dependant on the severity of biomechanical deficit
    • The orthotic prescription should be decided by the clinician, who should describe the prescription in detail in the patient records
    • Functional insoles in combination with eccentric exercises provides best outcomes.
  • Footwear adaptations or prescription

Third line intervention

(Stage 3 and 4)

Deformities become more severe and fixed with adaptive forefoot varus. Medial pain is more severe and lateral pain now a factor. The patient is unable to perform single heel raise test. Imaging shows degeneration of rear foot joints.

  • Correction using an articulated Ankle Foot Orthosis.
  • Immobilisation using a fixed Ankle Foot Orthosis.

Orthopaedic opinion

Surgical Opinion

One reason for referring to the orthopaedic department is for a surgical opinion. This is not a guarantee that surgery is the correct option for your patient so it’s important that this is not the expectation given to the patient by the referring clinician.

It is important that the patient has the option of a surgical opinion if this may be an appropriate treatment option for them so that they can discuss what is involved in surgery and make an informed decision.

Common conditions which are operated on include, hallux valgus, hallux rigidus, Morton’s neuroma, lesser toe issues, tendon pathology and degenerative changes of the joints of the foot and ankle.

The indications for surgery include persistent pain, worsening symptoms, significant limited mobility or failure of conservative therapy.

Foot and ankle surgery is generally successful with many of the common foot operations achieving 85% success rate, however complications can occur and will be considered as part of the decision making process for surgery.

Remember to exhaust all conservative means ie: orthotics, footwear advice , physiotherapy, pain relief medication , if appropriate steroid injections, before considering surgical opinion.

Further Investigation

The other reason for referral to Orthopaedics is for “Further Investigations”.

MRI and CT are helpful and can be arranged within orthopaedics as appropriate – if your patient does not have a clear diagnosis or there is a concern about a diagnosis and as above, struggling with symptoms, referral on to orthopaedics is appropriate

Things to consider before referring for further investigation are the severity of the symptoms and whether there are odd/suspicious symptoms making it difficult to make a clear diagnosis.

Things to consider before referring to Orthopaedics.

  • Before referring to orthopaedics ensure the following:
  • Vascular status – palpable pulses (for surgery)
  • Patient is happy to attend for further review, possible further investigation and possible surgery as an outcome.
  • Conservative means have been attempted.

This is a referral guide however please do not hesitate to contact your local ESP Orthopaedic clinician if you are unsure whether to refer.

Evidence base

The majority of the papers included here are level 1 or level 2 evidence, however other papers have been included to allow for further reading around the subject. Articles are listed in Harvard format.

Abousayed, M.M., Alley, M.C., Shakked, R. and Rosenbaum, A.J., 2017. Adult-acquired flatfoot deformity: etiology, diagnosis, and management. JBJS reviews, 5(8), p.e7.
Click here for Article

Bohm, S., Mersmann, F. and Arampatzis, A., 2015. Human tendon adaptation in response to mechanical loading: a systematic review and meta-analysis of exercise intervention studies on healthy adults. Sports medicine-open, 1(1), p.7.
Click here for Article

Kulig, K., Reischl, S.F., Pomrantz, A.B., Burnfield, J.M., Mais-Requejo, S., Thordarson, D.B. and Smith, R.W., 2009. Nonsurgical management of posterior tibial tendon dysfunction with orthoses and resistive exercise: a randomized controlled trial. Physical Therapy, 89(1), pp.26-37.
Click here for Article

Mousavi, S.H., Hijmans, J.M., Rajabi, R., Diercks, R., Zwerver, J. and van der Worp, H., 2019. Kinematic risk factors for lower limb tendinopathy in distance runners: a systematic review and meta-analysis. Gait & posture, 69, pp.13-24.
Click here for Article

Reeves, J., Jones, R., Liu, A., Bent, L., Plater, E. and Nester, C., 2019. A systematic review of the effect of footwear, foot orthoses and taping on lower limb muscle activity during walking and running. Prosthetics and Orthotics International, 43(6), pp.576-596.
Click here for Article

Ross, M.H., Smith, M., Plinsinga, M.L. and Vicenzino, B., 2018. Self-reported social and activity restrictions accompany local impairments in posterior tibial tendon dysfunction: a systematic review. Journal of foot and ankle research, 11(1), p.49.
Click here for Article

Ross, M.H., Smith, M.D. and Vicenzino, B., 2017. Reported selection criteria for adult acquired flatfoot deformity and posterior tibial tendon dysfunction: are they one and the same? A systematic review. Plos one, 12(12), p.e0187201.
Click here for Article

Ross, M.H., Smith, M.D., Mellor, R. and Vicenzino, B., 2018. Exercise for posterior tibial tendon dysfunction: a systematic review of randomised clinical trials and clinical guidelines. BMJ open sport & exercise medicine, 4(1).
Click here for Article

Editorial Information

Last reviewed: 13/11/2024

Next review date: 30/11/2025

Author(s): John Tougher, Laura Barr, Nikki Munro.

Version: 1

Reviewer name(s): John Tougher, Laura Barr, Nikki Munro.