BACKGROUND: Chopart injuries can be allocated into 4 broad groups, ligamentous injury with or without dislocation and fracture with or without dislocation, which must occur at the talonavicular joint (TNJ) and/or calcaneocuboid joint (CCJ). Chopart dislocations are comprised of pure-dislocations and fracture-dislocations. We aim to review the literature, to enable evidence-based recommendations.
METHODS: A literature search was conducted to identify relevant articles from the electronic databases, PubMed, Medline and Scopus. The PRISMA flow chart was used to scrutinise the search results. Articles were screened by title, abstract and full text to confirm relevance.
RESULTS: We identified 58 papers for analysis, 36 case reports, 4 cohort studies, 4 case series and 14 other articles related to the epidemiology, diagnosis, treatment and outcomes of Chopart dislocations. Diagnostic recommendations included routine imaging to contain computed tomography (CT) and routine examination for compartment syndrome. Treatment recommendations included early anatomical reduction, with restoration and maintenance of column length and joint congruency. For both pure-dislocations and fracture-dislocations urgent open reduction and internal fixation (ORIF) provided the most favourable long-term outcomes.
CONCLUSIONS: Chopart dislocations are a complex heterogenous midfoot injury with historically poor outcomes. There is a relative paucity of research discussing these injuries. We have offered evidence-based recommendations related to the clinical and surgical management of these rare pathologies.

BACKGROUND: Fractures of the anterior process of the calcaneus (APC) are easily overlooked in clinical practice. Most patients have good to excellent clinical outcome after conservative treatment, while some patients may have persisting symptoms and unfavorable functional outcomes. The aim of this study was to identify the risk factors associated with unfavorable functional outcome after conservative treatment in APC fractures.
METHODS: All patients presenting with APC fractures and receiving conservative treatment from April 2019 to April 2020 were retrospectively assessed. The primary outcome measurement was the ankle joint function assessed using Karlsson Scoring System at 2 years post-injury. The risk factors associated with unfavorable functional outcomes (Karlsson score ≤ 80) were evaluated by logistic regression analysis.
RESULTS: In total, 84 patients were included with a mean age of 40 years. 26 (31%) patients presented with unfavorable functional outcome at 2 years post-injury. In multivariate logistic regression, concomitant fractures of talonavicular (TN) joints and older age were significantly associated with unfavorable functional outcome (p<0.05). Patients with concomitant fractures of TN joints had an odds ratio of 3.623 for unfavorable functional outcome. The optimal cutoff age for an unfavorable outcome was ≥ 47.5 years, with an odds ratio of 5.010.
CONCLUSIONS: Most patients with APC fractures achieved good to excellent results when treated conservatively. Attention should be paid to those with concomitant fractures of TN joints and with age ≥ 47.5 years, which might lead to unfavorable functional recovery.
METHODS: IV; case series.

Open dislocations of the midfoot and subtalar joints are extremely rare injuries. Understanding the anatomy of these joints and the various injury patterns is imperative to obtain stable concentric reduction and provide good functional outcome. We present a report of a 26- year old male who was involved in a road traffic accident and sustained open dislocations of the calcaneocuboid, naviculocuneiform and subtalar joints. He initially underwent external fixation in view of the severe soft tissue injury. After improvement of the soft tissue condition, he underwent K-wiring of the calcaneocuboid joint, buttress plating of the talonaviculocuneiform joint, peroneal tendon reconstruction using hamstring allograft and defect coverage with a free anterolateral thigh flap. With appropriate rehabilitation protocols, patient recovered well and was allowed to weight bear as tolerated by 10 weeks. His wounds healed completely by 4 months. We report this case considering the rarity of the combined calcaneocuboid, naviculocuneiform and subtalar dislocations which were successfully managed.

BACKGROUND: Ankle sprain is a common injury in professional soccer, but to date midtarsal sprain has not been investigated in this context. The purpose of this study was to determine the prevalence of midtarsal sprain by MRI and to assess its impact on the time of return to play in professional soccer players.
METHODS: We included 52 professional soccer players who underwent 59 MRI examinations after acute ankle trauma between January 2012 and September 2019. Images were retrospectively reviewed in consensus by two radiologists for assessment of midtarsal sprain and ankle sprain. Ligaments were graded as i) normal, ii) partial tear, or iii) complete tear. Time to return to play (RTP) for each athlete was retrieved from team medical records. A Kruskal-Wallis test and Dunn\'s pairwise tests were used to calculate differences in RTP time between groups with i) isolated midtarsal sprain, ii) isolated lateral ankle sprain, and iii) combined midtarsal and lateral ankle sprain.
RESULTS: MRI revealed isolated ankle sprain in 24 of 59 MRI examinations (40.6 %). Acute midtarsal ligament injury was present in 15 examinations (25.4 %). Four of the 15 examinations (26.7 %) had isolated midtarsal injuries and eleven of the 15 examinations (73.3 %) had concomitant ankle sprain. RTP time was 39 days (range 9-70 days) for isolated midtarsal sprain. RTP time was significantly higher for athletes with combined ankle and midtarsal sprain (47 days, range 15-74 days) when compared to athletes with isolated ankle sprain (24 days, range 2-59 days) (p = .019).
CONCLUSIONS: Our MRI study reveals that midtarsal sprain is a frequent injury in professional soccer players with ankle sprain. Midtarsal ligament findings on MRI combined with evidence of lateral ankle sprain is associated with a longer time of return to play compared to isolated lateral ligament injuries.
METHODS: Retrospective study, observational study.

We present a detailed overview of anatomical and US features of ankle and midfoot ligaments based on our own dissections and cadaver studies as well as US imaging in cadavers and volunteers. The ligament anatomy about the ankle and midfoot is complex. Most ligaments are superficial and hence very well accessible for US. US technique to obtain optimal visualization however is difficult and requires a learning curve. We discuss US technique in detail for each individual ligament. We divided the ligaments in different groups: tibiofibular ligaments, Bassett\'s ligament, lateral collateral ligament complex (anterior talofibular ligament, calcaneofibular ligament, lateral talocalcaneal ligament, posterior talofibular ligament), medial collateral ligament complex, spring ligament, Chopart joint ligaments (bifurcate ligament, dorsal talonavicular ligament, lateral calcaneocuboid ligament, long and short plantar ligaments), Lisfranc ligaments, sinus tarsi ligaments.

The objective of this article is to review the normal anatomy and posttraumatic findings of the Chopart joint complex. Key imaging features of the normal ligaments and patterns of ligamentous and osseous injuries are discussed.
Traumatic midtarsal injuries, particularly midtarsal sprain, are often overlooked clinically and on imaging but are relatively common and typically are associated with inversion ankle injuries. Radiologists should be familiar with Chopart joint anatomy and the imaging features of midtarsal injuries because early diagnosis may help optimize clinical management.

Fractures to the anterior process of the calcaneus (PAC) have long been considered rare injuries and have received little attention in clinical research. On the contrary, recent studies have reported a distinct higher incidence, especially following ankle sprains. Decisive reasons are that fractures of the PAC are regularly missed on plain radiographs and that a clinical differentiation from injuries to the lateral ankle ligaments is difficult. With the broad availability of cross-sectional imaging modalities fractures of the PAC are diagnosed more frequently and more reliably. The purpose of this review is to give an overview on the diagnostics, classification and treatment recommendations to this topic and discuss the studies available. To date no evidence-based recommendations are available for the treatment of fractures of the PAC. The few case reports and case series published, predominantly recommend conservative treatment; however, the treatment regimens vary considerably, ranging from immobilization in a lower leg cast (2-10 weeks) to early functional treatment with full weight-bearing. The surgical treatment by open reduction and internal fixation has been described primarily for large dislocated fractures. Surgical excision is considered mainly in cases of persistent pain or symptomatic non-union following non-operative treatment. For both, non-operative and operative treatment, the case reports and case series report satisfactory outcomes for the majority of patients. Nevertheless, comparative studies and patient-rated outcome measures are missing. Therefore, evidence-based recommendations cannot be given.

OBJECTIVE: Injuries at the calcaneocuboid and talonavicular joint have been described as two distinct, unrelated entities in the radiology literature. Our purpose was to assess the coexistence of these injuries using radiography and MRI and to correlate our findings with radiologic and clinical diagnoses.
METHODS: Twenty-one patients with injury at the anterior calcaneal process on radiographs or MR images were retrospectively assessed for concomitant injury at the talonavicular joint. Radiologic and clinical diagnoses and treatment were documented. McNemar and kappa statistics were calculated; p values < 0.05 were considered statistically significant.
RESULTS: Radiographic and MRI rates of detection of injuries across the Chopart joint were statistically different. Calcaneocuboid avulsion fractures were evident on 48% of radiographs and 100% of MR images (p = 0.001). Talonavicular joint injuries were evident on 38% of radiographs and 76% of MR images (p = 0.008). Concomitant injury at both joints was evident on 14% of radiographs and 76% of MR images (p < 0.0001). Interrater agreement was 0.488-0.637 and 0.286-0.364 for talonavicular and 0.144-0.538 and 0.976-1 for calcaneocuboid injuries on radiography and MRI, respectively. Sixty percent of calcaneocuboid fractures were prospectively missed on radiography (none on MRI), whereas 38% and 25% of talonavicular findings were missed on radiography and MRI, respectively. Sixty percent of injuries were clinically misdiagnosed as ankle sprains. Chopart joint injury was never mentioned in prospective clinical or imaging diagnoses.
CONCLUSIONS: Calcaneocuboid and talonavicular injuries commonly coexist. Radiographs underestimate severity of injury; MR images show more subtle abnormalities. Lack of mention of Chopart joint injury clinically and on imaging reports underlies the need for greater familiarity with this entity.