Medial swivel dislocation with impacted navicular bone into the talar head: A case report

Abstract

Medial swivel dislocation is a rare subtype of midtarsal bone dislocation, mostly associated with fracture rather than isolated dislocation. It is caused by medially or laterally direct forces to the midfoot. In case of failed closed reduction of the deformity, the patient should undergo open reduction and stabilization of the injury as soon as possible. We are presenting a 17-year-old, male, who sustained a left ankle injury and presented with a deformity, closed reduction of the deformity failed multiple times, and the patient was taken for open reduction and stabilization of the deformity in the operating theater. Intra-operatively, the dislocation was locked with the lateral process of the navicular being impacted into the taller head. Six months following the injury the patient was back to his pre-injury status and did not have any recurrent dislocation of the midfoot.

Introduction

Midtarsal joint dislocation, which is composed of talonavicular, and calcaneocuboid articulations is a quite rare injury of the foot and ankle. This is attributed to its strong periarticular ligamentous support at this joint. This injury mostly affects middle-aged men, and most commonly is secondary to a major trauma and is generally associated with a fracture rather than an isolated pure dislocation [[1], [2], [3]].

A subtype pattern of these injuries is the swivel dislocation at the talonavicular joint (TNJ). A medial or lateral force to the forefoot can lead to a swivel dislocation at the talonavicular joint. Few reports discuss this type of injury pattern [[4], [5], [6], [7]]. We report a case of medial swivel dislocation of the TNJ associated with a significant impaction of the navicular bone into the talar head with talar body fracture and sustentaculum-tali fracture which failed closed reduction and required open reduction of the dislocation with stabilization of the sustentaculum-tali fracture.

Case report

A 17-year-old, male, presented to our emergency department with left ankle, pain, deformity, and inability to bear weight on the foot following a motor vehicle collision. Following the advanced trauma life support (ATLS) protocol, the patient was vitally stable and cleared from the trauma side. On examination of the left lower limb, there was significant deformity of the left ankle, the hindfoot was in varus and the forefoot was in supination, with intact overlying skin, no distal neurological deficit, an intact distal peripheral pulse, and a good capillary refill of the toes. The leg and foot compartments were soft with no positive signs of compartment syndrome. Also, the patient had flexion of the left big toe which is passively correctable.

A radiographic evaluation of the ankle showed medial subtalar dislocation and multiple attempts by a senior orthopedic resident and foot and ankle fellow of closed reduction under sedation were unsuccessful in the emergency department (Fig. 1). After failed closed reduction the patient was taken to the operating theater within an hour for open reduction and internal fixation of the foot injury.

Fig. 1.

(A) anteroposterior left foot radiographs, (B) anteroposterior and (C) lateral radiographs of the left ankle, demonstrating medial peri-talar dislocation with the navicular bone impaction into the talar head.

The injury first was approached from the lateral aspect. A lateral incision cantered over the sinus tarsi was done to expose the medially dislocated calcaneus and clear any interposing structure. When this attempt failed to reduce the dislocation, the surgeon's attention was diverted to the talonavicular dislocation as the second obstacle to reduction as these 2 joints need to be reduced together. A lateral longitudinal incision between the tibias posterior and tibialis anterior was made to expose the dislocated talonavicular joint. The dislocation was locked with the lateral process of the navicular being impacted into the taller head. But this attempt failed. Then a medial ankle incision was carried out over the tibialis posterior tendon, and soft tissue dissection was in layers till the dislocation was reached, initially, it was difficult to achieve the reduction, this was secondary to the impaction of the navicular into the medial head of the talus. Once this was identified, with the use of Hintermann distractor, a joint reduction was finally achieved.

Intraoperatively both deltoid ligament and peroneal tendons were intact, the sustentaculum tali were fractured with entrapment of the Flexor Hallucis Longus tendon (FHL) underneath it, causing big toe flexion deformity, and there was an area of bone impaction resembling the Hill-Sach lesion on the medial aspect of the talar head secondary to navicular impingement into the talar head (Fig. 2). Furthermore, once the deformity was reduced and the sustentaculum-tali fracture was stabilized with (1.1 mm) fully threaded K-wires, spontaneous reduction of the toe deformity was achieved. Then the wound was closed in layers, a sterile dressing was applied over the surgical wound and then a below-knee back slab was applied, and an immediate post-operative ankle CT scan was taken to confirm congruent reduction (Fig. 3).

Fig. 2.

intra-operative clinical picture demonstrating an area of bone impaction resembling the Hill-Sach lesion on the medial aspect of the talar head secondary to navicular impingement into the talar head.

Fig. 3.

(A) sagittal cuts, (B) coronal cuts, and (C) axial cuts immediate postoperative CT scan of the left ankle showing medial talar head bone impaction following open reduction of the dislocation, stable fixation of the sustentaculum tali and congruent reduction of the fracture.

The patient did not have any immediate or late surgical-related complications. He was discharged home on the 4th day following the surgery and was followed in the foot and ankle clinic regularly. Postoperatively he was started on non-weight-bearing ambulation with below-knee back slab for a total of 6 weeks. Then he was kept in aircast boots and was allowed for full weight bearing as the patient tolerated for another 6 weeks. And after 3 months, he was allowed to walk normally without any walking or orthotic devices. 6 months following the injury the patient was walking normally with no residual pain, had normal range of motion of the ankle and subtalar joints, and no collapse of the medial longitudinal arch compared to the normal side. Furthermore, A follow-up CT scan of the ankle 6 months post-operatively showed complete fracture healing and residual bone loss on the lateral aspect of the talar head (Fig. 4).

Fig. 4.

(A) sagittal cuts, (B) coronal cuts, and (C) axial cuts CT scan of the left ankle at 6 months follow-up showing complete fracture healing with congruent joints and no subluxation.

Discussion

Transverse tarsal joint dislocation is a rare injury of the foot and ankle. The rigid bony and ligamentous support surrounding the midtarsal joints are responsible for fractures associated with dislocation rather than pure dislocation involving these joints [8]. In 1975, Main and Jowett introduced a classification system for these injuries based on the direction of the deforming forces applied and the resulting deformity of the midtarsal joint [4]. They defined a medial or lateral swivel dislocation as a subtalar dislocation in which the calcaneocuboid joint and the subtalar joint remain intact but the navicular is medially or laterally dislocated from the talus [4].

Up to 80 % of the TNJ dislocations are medial and 17 % are lateral [9]. Lateral swivel dislocation is usually associated with an impacted fracture of the calcaneocuboid joint [10]. While medial swivel dislocation is not associated with such injuries. A non-displaced talar body fracture associated with a significant impaction of the navicular bone into the medial talar head fracture and a displaced sustentaculum-tali fracture were detected in our case report.

Richter et al. recommended in their study, that anatomical reduction was essential for good clinical outcomes, and functional restrictions in these injuries can be minimized by open reduction and internal fixation. However, closed reduction showed good outcomes with pure dislocations only [11]. However, In our case, closed reduction was attempted before the surgery but did not succeed, and eventually, the patient required open reduction with K-wire stabilization of the sustentaculum-tali.

Williams et al. explained in their case report that a medial head of talus fracture could occur secondary to capsular avulsion of the talus during dislocation and navicular impaction into the medial talar head, also, Algouaiz et al. have reported a similar mechanism. However, intraoperatively in our case, the navicular bone was impacted over the talus bone causing a fracture with significant bone impaction at the medial aspect of the talar head, this bone impaction was the main cause in preventing the reduction of the talonavicular dislocation. Taking this into consideration may prevent unsuccessful attempts of reduction and shorten surgical time.

Conclusion

Swivel dislocation is a rare injury that can be caused by medially or laterally directed forces to the midfoot. Usually, it is caused by a high-energy trauma. Proper diagnosis of this injury is essential to determine the right treatment and achieve a good prognosis. Treatment of such injury should consist of early closed reduction or open anatomical reduction. Anatomical reduction and surgical stabilization should be followed by a period of limb immobilization to allow proper soft tissue and bone healing. An impaction between the lateral process of the navicular and talar head should be thought of as a factor of a nonreducible dislocation.

Statements of ethics

Approved by our local institution's medical research center. Approval ID MRC-04-24-336.

Funding

Open access funding was provided by Qatar National Library.

Consent

A written informed consent was obtained from the patient's father to publish this case report and accompanying images. A copy of the written consent is available for review by the editor of this journal upon request.

CRediT authorship contribution statement

Ibrahim Saeed Ibrahim: Data curation, Methodology, Writing – original draft, Writing – review & editing. Isam Sami Moghamis: Data curation, Investigation, Methodology, Supervision, Writing – original draft, Writing – review & editing. Kareem Elsweify: Data curation, Methodology, Writing – review & editing. Jasim Alsaei: Data curation, Investigation, Methodology, Writing – review & editing. Ahmad AL-Saddi: Data curation, Methodology, Writing – review & editing. Mazhar Fuad: Data curation, Methodology, Project administration, Supervision, Writing – review & editing.

Declaration of competing interest

The authors have no competing interest to declare.