• The 3D anatomical complexity of the foot and ankle and the importance of weight-bearing in diagnosis have required the combination of conventional radiographs and medical CT.

• Conventional plain radiographs (XR) have demonstrated substantial limitations such as perspective, rotational and fan distortion, as well as poor reproducibility of radiographic installations. Conventional CT produces high levels of radiation exposure and does not offer weight-bearing capabilities.

• The literature investigating biometrics based on 2D XR has inherent limitations due to the technology itself and thereby can focus only on whether measurements are reproducible, when the real question is whether the radiographs are.

• Low dose weight-bearing cone beam CT (WBCT) combines 3D and weight-bearing as well as ‘built in’ reliability validated through industry-standardized processes during production and clinical use (quality assurance testing).

• Research is accumulating to validate measurements based on traditional 2D techniques, and new 3D biometrics are being described and tested.

• Time- and cost-efficient use in medical imaging will require the use of automatic measurements. Merging WBCT and clinical data will offer new perspectives in terms of research with the help of modern data analysis techniques.

Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170066

• Fractures of the lateral and the posterior processes of the talus are uncommon and frequently missed because of a low level of suspicion and difficulty in interpretation on plain radiographs. Missed fractures can lead to persistent pain and reduced function.

• Lateral process fractures are usually a consequence of forced dorsiflexion and inversion of fixed pronated foot. These are also commonly known as snowboarder’s fractures.

• The posterior process of the talus is composed of medial and lateral tubercles, separated by the groove for the flexor hallucis longus tendon.

• The usual mechanism of injury is forced hyperplantarflexion and inversion causing direct compression of the posterior talus, or an avulsion fracture caused by the posterior talofibular ligament. CT scans are helpful in cases of high clinical suspicion.

• There is a lack of consensus regarding optimal management of these fractures; however, management depends on the size, location and displacement of the fragment, the degree of cartilage damage and instability of the subtalar joint. Non-operative treatment includes immobilization and protected weight-bearing for six weeks. Surgical treatment includes open reduction and internal fixation or excision of the fragments, depending on the size.

• Fractures of the lateral and the posterior processes of the talus are uncommon but important injuries that may result in significant disability in cases of missed diagnosis or delayed or inadequate treatment. Early diagnosis and timely management of these fractures help to avoid long-term complications, including malunion, nonunion or severe subtalar joint osteoarthritis.

Cite this article: EFORT Open Rev 2018;3:85-92. DOI: 10.1302/2058-5241.3.170040

• Subtalar arthroereisis has been reported as a minimally-invasive, effective and low-risk procedure in the treatment of flatfoot mainly in children but also in adults.

• It has been described as a standalone or adjunctive procedure, and is indicated in the treatment of flexible flatfoot, tibialis posterior tendon dysfunction, tarsal coalition and accessory navicular syndrome.

• Different devices for subtalar arthroereisis are currently used throughout the world associated with soft-tissue and bone procedures, depending on the surgeon rather than on standardised or validated protocols.

• Sinus tarsi pain is the most frequent complication, often requiring removal of the implant.

• To date, poor-quality evidence is available in the literature (Level IV and V), with only one comparative non-randomised study (Level II) not providing strong recommendations. Long-term outcome and complication rates (especially the onset of osteoarthritis) are still unclear.

Cite this article: EFORT Open Rev 2017;2:438–446. DOI: 10.1302/2058-5241.2.170009

• Injuries to the tibioperoneal syndesmosis are more frequent than previously thought and their treatment is essential for the stability of the ankle mortise.

• Recognition of these lesions is essential to avoid long-term morbidity.

• Diagnosis often requires complete history, physical examination, weight-bearing radiographs and MRI.

• Treatment-oriented classification is mandatory.

• It is recommended that acute stable injuries are treated conservatively and unstable injuries surgically by syndesmotic screw fixation, suture-button dynamic fixation or direct repair of the anterior inferior tibiofibular ligament.

• Subacute injuries may require ligamentoplasty and chronic lesions are best treated by syndesmotic fusion.

• However, knowledge about syndesmotic injuries is still limited as recommendations for surgical treatment are only based on level IV and V evidence.

Cite this article: EFORT Open Rev 2017;2:403–409. DOI: 10.1302/2058-5241.2.160084

• Various types of re-alignment surgery are used to preserve the ankle joint in cases of intermediate ankle arthritis with partial joint space narrowing.

• The short-term and mid-term results after re-alignment surgery are promising, with substantial post-operative pain relief and functional improvement that is reflected by high rates of patient satisfaction.

• In this context, re-alignment surgery can preserve the joint and reduce the pathological load that acts on the affected area.

• Good clinical and radiological outcomes can be achieved in asymmetrical ankle osteoarthritis by understanding the specific deformities and appropriate indications for different surgical techniques.

Cite this article: EFORT Open Rev 2017;2:324-331. DOI: 10.1302/2058-5241.2.160021

• Subtalar joint anatomy is complex and can vary significantly between individuals.

• Movement is affected by several adjacent joints, ligaments and periarticular tendons.

• The subtalar joint has gained interest from foot and ankle surgeons in recent years, but its importance in hindfoot disorders is still under debate.

• The purpose of this article is to give a general overview of the anatomy, biomechanics and radiographic assessment of the subtalar joint.

• The influence of the subtalar joint on the evolution of ankle joint osteoarthritis is additionally discussed.

Cite this article: EFORT Open Rev 2017;2:309-316. DOI: 10.1302/2058-5241.2.160050

• Pathological abnormality of the peroneal tendons is an under-appreciated source of lateral hindfoot pain and dysfunction that can be difficult to distinguish from lateral ankle ligament injuries.

• Enclosed within the lateral compartment of the leg, the peroneal tendons are the primary evertors of the foot and function as lateral ankle stabilisers.

• Pathology of the tendons falls into three broad categories: tendinitis and tenosynovitis, tendon subluxation and dislocation, and tendon splits and tears. These can be associated with ankle instability, hindfoot deformity and anomalous anatomy such as a low lying peroneus brevis or peroneus quartus.

• A thorough clinical examination should include an assessment of foot type (cavus or planovalgus), palpation of the peronei in the retromalleolar groove on resisted ankle dorsiflexion and eversion as well as testing of lateral ankle ligaments.

• Imaging including radiographs, ultrasound and MRI will help determine the diagnosis. Treatment recommendations for these disorders are primarily based on case series and expert opinion.

• The aim of this review is to summarise the current understanding of the anatomy and diagnostic evaluation of the peroneal tendons, and to present both conservative and operative management options of peroneal tendon lesions.

Cite this article: EFORT Open Rev 2017;2:281-292. DOI: 10.1302/2058-5241.2.160047

• Orthobiologics are biological substances that are used therapeutically for their positive effects on healing skeletal and soft-tissue injuries. The array of orthobiological products currently available to the foot and ankle surgeon is wide, and includes bone allografts, bone substitutes, growth factors, and chondral scaffolds. Nonetheless, despite the surge in interest and usage of orthobiologics, there remains a relative paucity of research addressing their specific applications in foot and ankle surgery. In this review, we attempt to provide an overview of the literature on commonly available allogenic bone grafts and bone substitutes.

• There is Level II, III and IV evidence addressing allogenic bone grafts in primary arthrodesis and osteotomy procedures in foot and ankle surgery, which compares favourably with autogenic bone grafts in terms of fusion rates and clinical outcomes (often with fewer complications), and supports a Grade B recommendation for its use.

• Pertaining to bone substitutes, the multiplicity of products, coupled with a lack of large prospective clinical trials, makes firm recommendations difficult. Level II and IV studies of calcium phosphate and calcium sulphate products in displaced intra-articular calcaneal fractures have found favourable results in addressing bone voids, maintaining reduction and promoting union, meriting a Grade B recommendation. Evidence for TCP is limited to level IV studies reporting similarly good outcomes in intra-articular calcaneal fractures, warranting a Grade C recommendation. The use of demineralised bone matrix products in hindfoot and ankle fusions has been described in Level II and III studies, with favourable results in achieving fusion and good clinical outcomes, supporting a Grade B recommendation for these indications.

• Overall, despite the general lack of high-level evidence in foot and ankle surgery, allogenic bone grafts and bone substitutes continue to hold front-line roles in treating the bone defects encountered in trauma, tumour, and deformity correction surgery. However, more investigation is required before firm recommendations can be made.

Cite this article: EFORT Open Rev 2017;2:272–280. DOI: 10.1302/2058-5241.2.160044

• Cavovarus deformity can be classified by the severity of malalignment ranging from a subtle and flexible to a severe and fixed cavovarus deformity of the foot.

• In the mild cavovarus foot, careful clinical assessment is required to identify the deformity.

• Weight-bearing radiographs are necessary to indicate the apex of the deformity and quantify the correction required.

• Surgery is performed when conservative measures fail and various surgical procedures have been described, including a combination of soft-tissue releases, tendon transfers and osteotomies, all with the aim of achieving a plantigrade and balanced foot.

• Joint-sparing surgery is the best option in flexible cavovarus foot even in Charcot-Marie-Tooth (CMT) disease (peroneal muscular atrophy).

• Arthrodesis is indicated in severe rigid cavus foot or in degenerative cases.

Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160077. Originally published online at www.efortopenreviews.org

• Most of tumours of the foot are tumour-like (synovial cyst, foreign body reactions and epidermal inclusion cyst) or benign conditions (tenosynovial giant cells tumours, planta fibromatosis). Malignant tumours of the soft-tissue and skeleton are very rare in the foot and their diagnosis is often delayed with referral to specialised teams after initial inappropriate procedures or unplanned excisions. The adverse effect of these misdiagnosed tumours is the increasing rate of amputation or local recurrences in the involved patients. In every lump, imaging should be discussed before any local treatment. Every lesion which is not an obvious synovial cyst or plantar fibromatosis should have a biopsy performed.

• After the age of 40 years, chondrosarcoma is the most usual malignant tumour of the foot. In young patients bone tumours such as osteosarcoma or Ewing’s sarcoma, are very unusually located in the foot. Synovial sarcoma is the most frequent histological diagnosis in soft tissues. Epithelioid sarcoma or clear cell sarcoma, involve more frequently the foot and ankle than other sites. The classic local treatment of malignant conditions of the foot and ankle was below-knee amputation at different levels. Nowadays, with the development of adjuvant therapies, some patients may benefit from conservative surgery or partial amputation after multidisciplinary team discussions.

• The prognosis of foot malignancy is not different from that at other locations, except perhaps in chondrosarcoma, which seems to be less aggressive in the foot. The anatomy of the foot is very complex with many bony and soft tissue structures in a relatively small space making large resections and conservative treatments difficult to achieve.

Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160078. Originally published online at www.efortopenreviews.org