|Year : 2019 | Volume
| Issue : 1 | Page : 70-72
Peritalar fracture dislocation: A case report with review on its biomechanics
Raju Karuppal1, Jipin Gopi1, Jacob Mathew1, Sandhya Somasundaran2
1 Department of Orthopaedics, Government Medical College, Kozhikode, Kerala, India
2 Department of Ophthalmology, Government Medical College, Kozhikode, Kerala, India
|Date of Web Publication||19-Aug-2019|
Dr. Raju Karuppal
Karuppal House, Mukkam Post - 673 602, Kozhikode, Kerala
Source of Support: None, Conflict of Interest: None
Peritalar dislocations are very rare injuries involving a simultaneous dislocation to both the subtalar and talonavicular joints. Mostly, they result from high-energy trauma such as road traffic accident and may also result from sports injuries. The most common type is medial dislocation. An inversion force in medial dislocation and an eversion force in lateral dislocation are applied to a plantar flexed foot. The treatment modalities for most peritalar dislocations include closed reduction and below-knee cast, although surgical intervention may be required in failed close reduction. We report a case of medial peritalar dislocation and comminuted fracture involving the posterior aspect of the talus with literature review on its biomechanics. A thorough knowledge of the biomechanics is essential for its better understanding and successful reduction maneuver.
Keywords: Biomechanics, peritalar dislocation, talar fracture
|How to cite this article:|
Karuppal R, Gopi J, Mathew J, Somasundaran S. Peritalar fracture dislocation: A case report with review on its biomechanics. J Orthop Traumatol Rehabil 2019;11:70-2
|How to cite this URL:|
Karuppal R, Gopi J, Mathew J, Somasundaran S. Peritalar fracture dislocation: A case report with review on its biomechanics. J Orthop Traumatol Rehabil [serial online] 2019 [cited 2019 Nov 22];11:70-2. Available from: http://www.jotr.in/text.asp?2019/11/1/70/264735
| Introduction|| |
Peritalar dislocations are very rare injuries and refer to those injuries associated with dislocation of both talonavicular and talocalcaneal joints with intact tibiotalar joint. The term peritalar is most appropriate because it involves simultaneous dislocation of both the talocalcaneal and talonavicular joints and the tibiotalar remains intact. It represents approximately 1%–1.5% of all traumatic dislocations. They are classified into the following four types based on the direction in which the distal portion of the foot is displaced on the talus: medial, lateral, anterior, and posterior, with medial dislocation being the most common., The basic mechanics of this particular injury lies in the direction of deforming force on the plantar flexed foot.
| Case Report|| |
A 41 years old male patient presented to our emergency department in May 2017 following a road traffic accident. On examination, he had severe pain on his right ankle with inability to bear weight. There was varus deformity of the right foot with swelling. This was a closed type of injury with no distal neurovascular deficit.
X-ray of the right foot showed medial dislocation of the talonavicular and subtalar joints, with displacement of the calcaneus and navicular bones medially [Figure 1]. The dislocation was reduced by foot eversion and dorsiflexion under general anesthesia using image intensifier guidance. On post reduction X-ray, the lateral view showed a fracture involving the posterior process of the talus with well-reduced dislocation of both talonavicular and talocalcaneal joints [Figure 2]. Hence, he was advised for a computed tomography scan. In the post reduction computed tomography, the anatomical reduction of the talonavicular and talocalcaneal joints was confirmed. There was a comminuted fracture involving the posterior process of the talus, with fracture line extending to the talocalcaneal joint surface [Figure 3]. Because the fracture was in acceptable position, no further surgical management was planned. The foot was immobilized with a below-knee slab, and he was put on mild oral analgesics and rest. After 10 days when the edema was subsided, a below-knee cast was applied for a period of 5 weeks. Physiotherapy in the form of active and passive mobilization of the ankle, rearfoot, and mid-foot joints began after the removal of plaster casts. He was then allowed to bear the weight on walking. Although symptoms gradually improved, he had mild discomfort that remained particularly when started to walk after taking rest.
|Figure 1: Plain X-ray anteroposterior and lateral views showing medial talonavicular and talocalcaneal dislocations with intact tibio-talar articulation|
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|Figure 2: Post reduction lateral X-ray showing well-reduced dislocation with fracture involving the posterior process of the talus|
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|Figure 3: Computed tomography scan showing comminuted fracture involving the posterior aspect of the talus, with fracture line extending to the talocalcaneal joint|
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| Discussion|| |
Peritalar dislocations with no fractures of other bone of the foot are uncommon. These dislocations are classified based on the position of the foot in relation to the talus. The most common is the medial peritalar dislocation (70%–80%), followed by the lateral (10%–20%) and then the anterior and posterior. There are only few reports on their biomechanics and importance. The two types of normal movements occurring at the talonavicular and talocalcaneal joints are eversion, abduction, and dorsiflexion as a single movement and inversion adduction and plantar flexion as the other movement which are commonly referred to as “triplanar movements.” This has been attributed in the mechanism for a variety of dislocations occurring around the talus. The proposed mechanism of medial dislocation is forceful inversion of the forefoot during which the neck of the talus pivots with the sustentaculum tali as a fulcrum, resulting in dislocation of the talanavicular joint followed by dislocation of the subtalar joint and finally, the peritalar dislocation., Medial dislocations are more frequent than other types of dislocations which might be due to our natural tendency during a fall from height, to land with foot in plantar flexion and inversion of the ankle. Inokuchi et al. divided medial dislocations into two subtypes: (1) swing, in which the calcaneus bone rotates medially but remains under the talus and (2) shift, in which the calcaneus is directly shifted medially besides the talus. Whereas forceful eversion of the foot is the mechanism of lateral dislocations where the anterior calcaneal process acts as the fulcrum for the anterolateral corner of the talus. This forces the head of the talus through the talonavicular capsule, leading to lateral dislocation of calcaneus on talus and then follows the talanavicular dislocation., The ideal treatment of these injuries is immediate closed reduction. The reduction in majority of cases will be stable. The common reasons of irreducibility for medial dislocations reported are buttonholing of the talar head through the extensor retinaculum, talanavicular ligament and joint capsule, impingement by bony fragments, interpositioning of the extensor digitorum brevis, etc.
The most important modality is the direct reduction of these dislocations followed by a short leg cast for 4 to 6 weeks. Reduction maneuver should be in the reverse order of phases of the dislocation. Hence, knowledge of their biomechanics has utmost importance. Medial dislocation is usually associated with good prognosis, whereas lateral dislocation and open injuries have a poor prognosis.
| Conclusion|| |
Peritalar dislocations are rare injuries which require immediate closed anatomical reduction. If this is not successful, then open surgical reduction is required. A thorough knowledge of the biomechanics is important for its better understanding and successful reduction maneuver.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
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[Figure 1], [Figure 2], [Figure 3]