Plantar midfoot

Tibialis Posterior Tendon Dysfunction (Adult Acquired Flatfoot Deformity)

Testing tibialis posterior strength

Significant History/Physical symptoms

Posterior tibial tendon dysfunction (PTTD) is a term that covers a constellation of signs and symptoms. It is also referred to as adult acquired flatfoot deformity (AAFFD) as a diagnostic term, however, as the condition is more complex than simply a dysfunction of the tibialis posterior muscle and tendon, more recently, a  consensus statement suggested we name it 'Progressive collapsing foot deformity'. This acknowledges the involvement of the complex ligamentous structures - specifically the deltoid and spring ligaments, the plantar fascia and other medial tendons. Conservative treatment is advocated early as mild deformity can progress rapidly and lead to increasing pain and loss of function for the patient.

Problems in this area can be purely mechanical due to weakness or trauma to the tibialis posterior tendon which may result in the medial ligaments becoming stretched and a flatfoot can result. The loss of strength can be sudden or gradual. Gait will likely then be adversely disrupted. Important to consider also though that there may be inflammatory, metabolic or hormonal reasons that are contributing to the pain.

The diagnosis is generally based on clinical evaluation and imaging is not always required. However it can be useful if there is the suspicion of underlying systemic causes, or if the patient is not responding to conservative management. Diagnostic ultrasound has the advantages of being more convenient to use in clinics, it is cheaper, and it has the ability to be used to perform real-time examinations however MRI can detect secondary signs such as bone marrow oedema, which ultrasound cannot.

• 3 times more common in females
• ≥ 40 years old
• pain location medial ankle/foot
• aggravated by activity
• patient may recall traumatic (often minor) event
• difficulty walking on uneven ground

Less Common Differential Diagnoses not included in this pathway:

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

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.

• Leaflet on Painful Flatfoot
• Painful Flatfoot - PUNJABI

Guidance for treatment duration and escalation

First line Intervention should be given for 8-12 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.

In acute phase, unloading is achieved by various means including activity limitation, rehabilitation exercises such as stretching of the relevant muscles, strapping and orthoses. Calf stretches are essential to the management of PTTD 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.

This is followed by a period of controlled loading which is achieved by targeted strengthening exercises for the affected muscles/tendon - as well as the rest of the kinetic chain if applicable - increased activity levels, and orthoses. Emphasis should then be placed on on the patient to independently self-management through re-iteration of education using the biopsychosocial model.

In the initial stages exercises help to strengthen weak muscles and improve foot function. Below are some videos that may help.

• Video on open kinetic strengthening for tibialis posterior
• Video on closed kinetic chain strengthening of tibialis posterior
• Video on Tinel's sign

Initial Patient Directed Treatment Options

• • Advise weight loss if appropriate.
  • Obesity is associated with a chronic low-grade inflammatory state, which can negatively affect tendon health. 
  • Signposting to activities which may promote weight loss link exit/parallel pathways
  • Referral to Weight Management Service if BMI greater than 30.
  • NHS Choices - Lose weight
  • Leisure Pathway
  • Activity modification and management advice
  • Analgesia & Non-Steroidal Anti Inflammatory Drugs as appropriate.
  • See guidance on good practice for analgesia advice.
  • PEACE and LOVE (Protect, Elevate, Avoid anti-inflammatory modalities, Compress, Educate, Load, Optimisation, Vascularisation and Exercise)
  • Footwear Advice
  • Increased width of heel sole / increase support around ankle, with low but not flat heel height.
  • Give leaflet to reinforce verbal advice - NHSGGC Footwear Advice Leaflet
  • Alternative Shoe Lacing Options
  • 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 - unless related to an system inflammatory condition but unlikely to be 1st line.

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.

(Stage 2)

• Biomechanical assessment and prescription of Foot Orthoses
  • 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 orthoses prescription should be decided by the clinician, who should describe the prescription in detail in the patient records
  • Evidence suggests that functional insoles in combination with loading based rehabilitation exercises provides best outcomes.
• Footwear advice, adaptations or prescription

(Stage 3 and 4)

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

• Hard-shell insoles may be used in instances where EVA insoles have been unsuccessful
• Articulated Ankle Foot Orthosis can be used to apply greater therapeutic forces to the foot and ankle
• Fixed Ankle Foot Orthosis can be used to reduce joint motion at the ankle

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.

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

Arain A, Harrington MC, Rosenbaum AJ., 2024. Progressive Collapsing Foot Deformity. NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

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

Myerson MS, Thordarson DB, Johnson JE, et al. Classification and Nomenclature: Progressive Collapsing Foot Deformity. Foot & Ankle International. 2020;41(10):1271-1276. 

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