Missed and associated injuries after subtalar dislocation: the role of CT

Closed medial subtalar dislocation: A case report and literature review

Subtalar dislocation is characterized by simultaneous dislocation of the subtalar (talocalcaneal) and talonavicular joints, hence the name talocalcaneonavicular. These lesions can be grouped into four distinct categories: anterior and posterior, which are exceptional, lateral and medial. Medial subtalar dislocations are more frequent, are due to low-energy trauma and generally have good functional results. Anatomical reduction and stabilization of the subtalar joint and optimal management of all associated foot injuries are the key to good results.

What Are the Risk Factors for Infection After Operative Treatment of Peritalar Fracture Dislocations?

OBJECTIVE

To assess the risk factors associated with deep infection after operative treatment of peritalar fracture dislocations.

DESIGN

A retrospective study was performed to identify patients who had operative treatment of a peritalar fracture dislocation over an 11-year period (2008-2019).

SETTING

Level 1 trauma center.

PARTICIPANTS

Patients were identified by review of all surgical billing that included open reduction of peritalar dislocation. Minimum follow-up for inclusion was 3 months or the outcome of interest. A total of 178 patients were identified, and 154 patients met inclusion criteria.

MAIN OUTCOME

The primary outcome was deep infection, defined as return to the operating room for debridement with positive cultures.

RESULTS

A total of 19 (12.3%) patients developed a postoperative deep infection. The most common associated fractures were talus (47%), calcaneus (33%), and fibula (9%) fractures. The infected group was significantly older (47.2 vs. 39.5 years, P = 0.03). Patients undergoing operative management for peritalar fracture dislocations with current smoking were found to have significantly higher odds of postoperative deep infection (74 vs. 34%, adjusted odds ratio = 7.4, 95% confidence interval, 2.3-24.1, P = 0.001). There was a significantly higher risk of infection in patients with a Gustilo-Anderson type 3 open fracture (32 vs. 12%, adjusted odds ratio = 5.7, 95% confidence interval, 1.6-20.3, P = 0.007). The infected group had high rates of below knee amputation when compared with the group without infection (47 vs. 1%, P < 0.001).

CONCLUSION

In our retrospective study, risk factors for infection after peritalar fracture dislocation included older age, smoking, and Gustilo-Anderson type 3 open fracture.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Subtalar dislocation: a narrative review

Background

Subtalar joint dislocation (1% of all dislocations) is the permanent loss of articular relationships in the talonavicular and talocalcaneal joints, without other involvement of the foot. Dislocation can occur medially (85%), laterally (15%), posteriorly (2.5%) and anteriorly (1%). Reduction can be performed by closed or open technique; lateral dislocations often require open reduction because of inclusion of soft tissues or bone fragments. Lateral dislocations are frequently complicated by bone exposure, risk of infection and associated soft tissues injuries.

Aim of the study

The aim of this study is to explain main characteristics and to clarify the most important pitfalls of subtalar dislocations.

Materials and methods

We examined 47 articles published in the last thirty years (389 cases). For each dislocation we reviewed its main characteristics: direction, bone exposure, need for open reduction and for surgical stabilisation, associated injuries and method used for diagnosis.

Results

Medial dislocations (68.1%) has greater incidence compared to lateral ones (27.7%). Bone exposure (44.5%), associated lesions (44.5%) and need for surgical reduction (48.2%) are much more represented in lateral dislocation than in the others.

Conclusions

Subtalar dislocations, especially the lateral one, represent a challenge for surgeons. Lateral subtalar dislocation occurs following high-energy trauma often involving associated injuries. Closed reduction could be unsuccessful and patients must undergo surgical reduction. After reduction CT scan is recommended. Our narrative review confirms these findings.

Subtalar Dislocations

Subtalar dislocations are uncommon injuries that involve disruption of the talocalcaneal and talonavicular joints. Whereas medial subtalar dislocations are usually caused by low-energy mechanisms and are reducible by closed means, lateral subtalar dislocations occur due to high-energy trauma, have associated foot injuries, and may require open reduction. Good outcomes can be expected for low-energy medial dislocations, whereas high-energy dislocations have guarded outcomes. Hindfoot deformity and chronic instability can result from nonanatomic reduction and inadequate stabilization. Arthrosis of the subtalar joint can occur despite anatomic reduction and is attributable to the cartilage damage at the time of injury.

A Rare Case of Fractured Posterior Facet of the Talus in Association With Open Medial Subtalar Dislocation

Subtalar or peritalar dislocation is the loss of contact between the articular surface of the talus distally and the calcaneum and navicular. In this paper, a case of open medial type of subtalar dislocation associated with fractured posterior facet of the talus in a 27-year-old man with a history of road traffic accident was reported. Immediate wound irrigation and open reduction under general anesthesia at the emergency room operation theater was successful followed by cast immobilization. At one-year follow-up, the patient was walking and carrying out his daily activities with mild restriction of inversion and eversion movements. Extensive wound debridement followed by immediate reduction and, when required, stabilization are the principal features of management. Open subtalar dislocation is an extremely rare injury and often poses a treatment dilemma. Early debridement and open reduction of the dislocation like in our case can give good functional outcome for an open medial subtalar dislocation at one-year follow-up. Temporary stabilization of dislocation in the form of Kirschner wires maybe needed in some cases only.

Traumatic Injury to the Subtalar Joint

Traumatic injury to the subtalar joint occurs during subtalar dislocations, talar and calcaneal fractures, and fracture-dislocations. After closed reduction of subtalar dislocations, peripheral talar or calcaneal fractures need to be ruled out by computed tomography scanning. In fractures and fracture-dislocations of the talus and calcaneus involving the subtalar joint, anatomic reconstruction of joint congruity is essential for functional rehabilitation. Failure to anatomically reduce the subtalar joint potentially leads to chronic instability, subtalar arthritis and posttraumatic hindfoot deformity. Despite adequate management, subtalar arthritis may develop as a result of primary cartilage damage at the time of injury.

Surgical Treatment of Posteromedial Talus Fractures: Technique Description and Results of 10 Cases

BACKGROUND

The aim of this study is to describe a surgical technique for successful treatment of posteromedial talar body fractures and establish treatment recommendations for fractures of the posterior aspect of the talus.

MATERIALS AND METHODS

Ten patients treated operatively for a posteromedial talar body fractures entering both the subtalar and ankle articulations with a minimum of 1-year followup were identified from a trauma database. Age, mechanism of injury, associated injuries, time to surgery, complications, the range of motion, secondary procedures, and need for arthrodesis were evaluated.

RESULTS

Followup averaged 4.8 years (1-10). Eight of ten patients had high-energy mechanisms of injury. Six patients had associated medial subtalar dislocations with two open. Associated injuries were common. No surgical complications occurred. The range of motion was present but decreased. No arthrodesis procedures were performed.

CONCLUSIONS

Operative fixation of posteromedial talus fractures with the described surgical technique resulted in acceptable outcomes in this series of patients with improved outcomes when compared to prior reports in the literature.

Lateral Subtalar Dislocation with Tarsometatarsal Dislocation: A Case Report of a Rare Injury

Dislocation of the fourth and fifth tarsometatarsal joints in conjunction with lateral subtalar dislocation is a rare occurrence. Little is known about the mechanism of injury, the appropriate treatment for this condition, and its ultimate prognosis. In this report, we describe this atypical presentation in a middle aged, otherwise healthy male who sustained a trivial twisting injury to the ankle when he slipped and fell on ice. Open reduction and K-wire fixation were necessary to affix the lateral tarsometatarsal and talonavicular joints. At one year postoperatively, he was able to return to his preinjury occupation with mild to moderate pain with prolonged walking. His Foot and Ankle Disability Index and American Orthopaedic Foot and Ankle Society scores were 64 and 65 points, respectively. Surgical intervention resulted in a stable plantigrade foot; however, the patient had early radiographic evidence of posttraumatic arthritis in the midfoot joints at one-year follow-up.

Irreducible Subtalar Dislocation Caused by Sustentaculum Tali Incarceration

INTRODUCTION

Subtalar dislocation is an uncommon lesion in traumatology chiefly when it concerns the lateral form. Surgical treatment is required when a fracture is related or the dislocation is irreducible. Even well treated, these dislocations progress unavoidably to subtalar arthrosis, which stays well tolerated.

CASE REPORT

A 46-year-old male with irreducible lateral subtalar dislocation caused sustentaculum tali incarceration confirmed on computed tomography (CT). The patient underwent emergent open reduction and internal fixation; the sustentaculum tali was reduced and fixed with a compression screw. At 3 years, "American Orthopaedic Foot and Ankle Society Ankle-hindfoot" score was 86, and the functional result was considered excellent despite a Grade I subtalar osteoarthritis on the ankle X-ray.

CONCLUSION

An irreducible subtalar dislocation is exceptionally due to the incarceration of sustentaculum tali. CT is of great interest for good fracture analysis and management planning. Anatomical reduction of the articular surfaces, stable osteosynthesis, sufficient immobilization, and a well-conducted rehabilitation are the only guarantors of a good functional outcome.

A Closed Lateral Subtalar Dislocation With Checkrein Deformity of Great Toe due to Entrapment of Flexor Hallucis Longus: A Case Report

Closed lateral subtalar dislocation is a very rare injury. We report a case of closed lateral subtalar dislocation with entrapment of flexor hallucis longus tendon producing a checkrein deformity. The patient was managed immediately with closed reduction under regional anesthesia and fixated with percutaneous Kirschner wires. Early mobilization and weightbearing was started and there were no complications till the last follow-up visit.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Case study.

Posteromedial Approach for Open Reduction and Internal Fixation of Talar Process Fractures

Fractures of the posteromedial process of the talus are frequently the result of high-energy trauma to the lower extremity. The treatment of these uncommon injuries may be unfamiliar and challenging to many surgeons. Significant pain and disability can result if these injuries are not recognized or treated appropriately. Open reduction and internal fixation via a posteromedial approach with screws is a mainstay of operative treatment for simple fractures. In cases of fracture impaction and/or comminution, a medial uniplanar external fixator may be used to improve intraoperative fracture visualization and mini-fragment plates and screws can be used to secure areas of comminution.

LEVEL OF EVIDENCE

Level V, expert opinion.

Subtalar dislocations

Subtalar dislocations make up 1-2% of all dislocations, about 75% of them being medial dislocations. Treatment consists of early reduction under adequate sedation. In cases of soft tissue interposition or locked dislocations, open reduction is warranted. More than 60% of subtalar dislocations are associated with additional fractures, therefore a postreduction CT is recommended. Complications include avascular necrosis of the talus, infection, posttraumatic arthritis, chronic subtalar instability, and complex regional pain syndrome with delayed reduction. The prognosis of purely ligamentous injuries is excellent after early reduction. Negative prognostic factors include lateral and open dislocations, total talar dislocations, and associated fractures.

Missed peritalar injuries: an analysis of factors in cases of known delayed diagnosis and methods for improving identification

Because of the complex anatomy of the foot, rarity of fractures of the foot, and subtle radiographic cues, foot injuries are commonly overlooked and mis/undiagnosed. This study seeks to investigate a patient population whose peritalar injuries, including fractures and dislocations, were missed on initial examination, in order to analyze factors of known, missed injuries and provide insight into methods for reducing the incidence of missed diagnoses. Surgical cases between January 1999 and May 2011 were queried and retrospectively reviewed to identify missed peritalar injuries. Of 1682 surgical cases reviewed, 27 patients with missed peritalar injury(ies), which were subsequently confirmed by imaging studies, were identified. Using the Orthopaedic Trauma Association classification, fracture and dislocation subtypes were classified. A medical record review was performed to assess demographic and surgical data elements. In this study population, 7 types of peritalar injuries (talus, calcaneal, navicular, and cuboid fractures as well as subtalar, calcaneocuboid, and talonavicular joint dislocations) were diagnosed in 27 patients. All patients required surgical intervention. Talus fractures were the most commonly missed injury. In patients with multiple peritalar injuries, there was a strong correlation between talus and navicular fractures (r = -0.60; P < .01) as well as a moderate correlation between talus fractures and calcaneocuboid dislocations (r = -0.46; P = .02). The presence of a calcaneal fracture significantly decreased the time to definitive diagnosis (P = .01). Male patients' diagnoses were delayed an average of 324 days and females 105 days (P = .04). A moderate correlation was found between patient age at injury and time to diagnosis (r = -0.47; P = .04), with a decreased time to diagnosis as patient age increased. Significant factors were identified in this patient population, including patient sex and age, which may contribute to missed or delayed diagnosis in the clinical setting. Prompt and accurate diagnosis of peritalar injuries may improve long-term outcomes.

LEVELS OF EVIDENCE

Care Management, Level V.

Subtalar instability: diagnosis and treatment

Subtalar instability is challenging to diagnose. It rarely follows a complete subtalar dislocation, an event more likely to result in subtalar pain, stiffness, and arthritis. By history, subtalar instability can be suggested by the patient’s feeling of ankle instability, easy “rolling over,” and a need to look at the ground constantly when walking. Clinical measures for inversion and eversion do not accurately reflect isolated subtalar motion, as soft tissue and other joint motion confound the examination. Stress radiographs have high false positive rates. Magnetic resonance imaging can show injured or disorganized ligaments suggestive of recurrent subtalar strain, but are not dynamic studies and cannot alone diagnose instability. Operative treatment, when elected, should focus on determining the source of the problem. Generally direct repair of the lateral ligaments is sufficient. Bony malalignment should always be considered especially in the setting when previous ligament reconstruction has failed.

Lateral subtalar dislocation associated with bimalleolar fracture: case report and literature review

Subtalar dislocation is an uncommon injury that affects the talocalcaneal and talonavicular joints, with the tibiotalar and calcaneocuboid joints remaining intact. The 4 types of subtalar dislocation are medial, lateral, anterior, and posterior, although the latter 2 are rare. These injuries-especially lateral dislocation-occur as a result of high-energy trauma. Medial dislocation is the most common type, and lateral dislocation is associated with osteochondral fractures of the talus and calcaneus, as well as with open injuries; hence, its worse prognosis. We report the case of a 62-year-old woman diagnosed with lateral subtalar dislocation accompanied by an ipsilateral bimalleolar fracture after a fall downstairs. She underwent emergency reduction of the dislocation under sedation. Surgical treatment of the bimalleolar fracture was delayed 9 days to avoid cutaneous complications. This is the first report of a subtalar dislocation accompanied by a bimalleolar fracture.

Isolated subtalar dislocation

BACKGROUND

Little attention has been devoted to subtalar dislocations without an associated bone injury in the literature to date. The aim of this study was to assess the functional and subjective results of a cohort of patients with this injury.

METHODS

A total of ninety-seven patients with a subtalar dislocation were treated at two major university trauma centers from January 1994 to March 2007. Computed tomographic scans indicated a subtalar dislocation without associated bone injury in twenty-three of these patients. Clinical and radiographic examinations were performed on all twenty-three patients at an average of 58.3 months after the completion of treatment. The postoperative clinical examination was supplemented by the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, and the degree of arthritis was assessed radiographically.

RESULTS

The average score on the AOFAS ankle-hindfoot scale score was 82.3 points. Twenty-one patients achieved a good result, and two patients had a satisfactory result. The range of motion of the subtalar joint was an average of 41.3 degrees. No difference between the results of the medial and lateral subtalar dislocations was observed. Only six patients had minor radiographic changes.

CONCLUSIONS

The intermediate-term results for a subtalar dislocation without an associated osseous injury are good, and the direction of the dislocation does not appear to make a difference with regard to clinical or radiographic outcome.

[Functional and subjective results following subtalar dislocations]

BACKGROUND

The objective of our study is to evaluate the functional and subjective results following subtalar dislocations without any associated bone injuries and to examine whether the direction of dislocation has any effect on the post-traumatic results.

METHODS

Over the period from February 1998 to May 2006, 56 patients with a subtalar dislocation were enrolled in the study. A subtalar dislocation without any associated bone injuries was only present in 13 patients. Follow-up examination after an average of 39.8 months was performed using the AOFAS Ankle-Hindfoot scale. The adapted classification developed by Altman was used to assess the post-traumatic degree of arthrosis radiologically.

RESULTS

The average AOFAS score was 81, with good results in 11 patients and satisfactory results in 2 patients. The range of motion (ROM) for the ankle-hindfoot joint was 39.2 degrees .

CONCLUSION

Despite the severity of the injury, the functional and subjective results of subtalar dislocations without any bone injuries are good. Generally, no early post-traumatic arthrosis occurs if there are no associated bone injuries. No differences were established between medial and lateral subtalar dislocations.

Process and tubercle fractures of the hindfoot

Process and tubercle fractures of the talus and calcaneus can be a source of significant pain and dysfunction. Successful management requires extensive knowledge of the complex osseoligamentous anatomy of the hindfoot. The large posterior process of the talus is composed of a medial and a lateral tubercle; an os trigonum may exist posterior to the lateral tubercle. The talus has a lateral process that articulates with the fibula and subtalar joint; the calcaneus possesses a frequently injured anterior process that articulates with the cuboid. Injury to these hindfoot structures is caused by inversion and eversion of the ankle, which can occur during athletic activity. These injuries often are misdiagnosed as ankle sprains. A high degree of clinical suspicion is warranted, and specialized radiographs or other imaging modalities may be required for accurate diagnosis. Nonsurgical management with cast immobilization is frequently successful when the fracture is correctly diagnosed acutely. Large fragments may be amenable to open reduction and internal fixation. Untreated, chronic injuries can cause significant pain and functional impairment that may be improved substantially with late surgical intervention.

Anterior Subtalar Dislocation: A Case Report

Anterior subtalar dislocations are extremely rare. To our knowledge, six cases have been reported in detail in the literature, but for only two of these was an anteroposterior view radiograph used to confirm the diagnosis. We report a case of anterior subtalar dislocation in which the posterior tibialis tendon was incarcerated in the talonavicular joint and that required an open reduction. We discuss the diagnosis, mechanism, and treatment.

Multislice CT in imaging of trauma of the spine, pelvis and complex foot injuries

Multislice CT (MSCT) has greatly enhanced the performance of CT scanners and has vastly improved imaging of musculoskeletal trauma. Fast, high resolution scanning is now possible. In our institution, MSCT is an essential part of the imaging of the traumatized patient. The advantages of volume imaging, such as multiplanar reconstructions (MPRs) with near isotropic viewing, three-dimensional imaging and thick slice (wedge) MPRs (mimicking conventional radiographs), enable more accurate assessment of complex anatomical areas such as the spine, pelvis and foot. We discuss the general principles of scanning for musculoskeletal trauma and describe our experience of MSCT of the traumatized spine, pelvis and foot.

Pseudo os trigonum sign: missed posteromedial talar facet fracture

BACKGROUND

Posteromedial talar facet fracture (PMTFF) is a rare injury, sparsely reported in the literature. This article proposes that PMTFF is often left undiagnosed by orthopaedic surgeons and suggests the routine application of advanced radiographic studies (i.e., CT scan) in the recognition of PMTFF. It also evaluates nonoperative management of PMTFF.

METHODS

After obtaining Institutional Review Board approval, the medical records over a 5-year period (1997-2001) were retrospectively reviewed from the foot and ankle service of a level 1 trauma center, identifying all cases of PMTFF. Charts were reviewed for relevant data. Results of treatment were assessed during follow-up physical examination.

RESULTS

Six cases of PMTFF were identified over a 5-year period. All injuries were associated with medial subtalar joint dislocation. Four of six (66%) patients were not initially diagnosed with PMTFF, but instead misdiagnosed as an os trigonum. The remaining two patients had an established diagnosis of PMTFF at the time of initial treatment. All had short leg cast immobilization for medial subtalar dislocation. CT evaluation yielded additional diagnoses in all six patients. All six patients showed a PMTFF. Five patients (83%) revealed persistent subtalar joint subluxation. Five of six (83%) patients required at least one additional procedure as a result of an undiagnosed or nonoperatively treated PMTFF. Four patients underwent subtalar joint fusion, and one patient underwent tibiotalar calcaneal fusion secondary to concomitant ankle/subtalar arthritis. The patient who did not undergo recommended fusion continued to be symptomatic.

CONCLUSIONS

Diagnosis of PMTFF necessitates a heightened clinical suspicion, especially when a medial subtalar joint dislocation is present. Proper imaging studies, such as coronal CT scan, should be performed after any subtalar dislocation. Timely treatment, in the form of open reduction and internal fixation for large fragments involving the articular surface or surgical excision for smaller fragments, is recommended in order to restore proper anatomy and function of the subtalar joint. This study verifies the significant morbidity associated with an undiagnosed or nonoperatively treated PMTFF.

Injury characteristics and the clinical outcome of subtalar dislocations: a clinical and radiographic analysis of 25 cases

The objective of this study was to determine the mechanisms of injury and pattern of associated foot and ankle injuries and systemic injuries associated with subtalar dislocations, and, correlate these data with the radiographic and clinical/functional outcome of patients after subtalar dislocation.

RESULTS

Twenty-five patients with a subtalar dislocation were identified over a seven year period. The mean patient age was 38 years. Males (n=19) comprised 76% of patients, with a mean age of 36 years. High energy mechanisms (motor vehicle accidents, falls) accounted for 68% of subtalar dislocations. Although high energy mechanisms showed a strong trend toward open subtalar dislocations, the association was not statistically significant (p=0.0573, Fisher's exact test). Closed dislocations predominated (75%). Left and right-sided dislocations were nearly equally distributed, even among motor vehicle accidents. Medial dislocations predominated (65%): these were not influenced by mechanism of injury and did not result in statistically lower AOFAS ankle/hindfoot scores. Subtalar dislocation was irreducible (requiring open reduction) in 32%, with higher energy mechanisms of injury being statistically associated with an irreducible subtalar dislocation (p=0.0261, Fisher's exact test). Block to reduction was evenly distributed among soft tissue elements (posterior tibial tendon, flexor hallucis longus tendon, capsule, extensor retinaculum) and osseous elements. Eighty-eight percent of patients incurred concomitant injuries to the foot and ankle (95% of which were closed injuries), namely, the ankle and talus. Systemic injuries occurred in 88% of patients. At a mean follow-up of five years, the mean AOFAS score of the subtalar dislocation side was significantly lower (mean=71 vs. 93, p=0.0007, unpaired Student's t-test). No statistical relation was found between the number of associated extremity injuries and AOFAS score (Spearman correlation coefficient, r=(-)0.236, p=0.331). Radiographic follow-up demonstrated 89% of ankles with radiographic changes (31% symptomatic); however, the majority of these patients (61%) had an associated ankle injury. The subtalar joint demonstrated radiographic changes in 89% of patients, with 63% being symptomatic; 75% of patients with subtalar joint changes incurred a fracture about the subtalar joint at the time of dislocation. Four patients went on to subtalar fusion at an average of 8.8 months post-dislocation. The midfoot showed radiographic changes in 72% of patients, with only 15% of these patients being symptomatic. All patients with midfoot symptoms were well controlled by nonsurgical measures.