Introduction

The peritalar dislocation is a rare injury (₁,₂,₃,₄,₅,₆). It consists of the simultaneous displacement of talocalcaneal (subtalar) and talonavicular joints, with no associated fracture at the talar neck or body, and without any compromise of talocrural (ankle) and calcaneocuboid joints (₆,₇,₈,₉,₁₀,₁₁,₁₂). Peritalar dislocation represents around 1% to 2% of all traumatic dislocations (₁₃) and 15% of all talar injuries (₂, ₆,₇,₈, ₁₄). Most affected patients are young and male at the third decade of life (₈, ₁₅). 50% to 80% of peritalar dislocations are caused by a violent trauma resulting from motorcycle or car accidents or from a fall from height. Some injuries are caused by a torsional trauma associated to sports activities, and are called “basketball foot” (₆, ₈, ₁₅). Medial peritalar dislocations represent 80% cases, four-fold more often than lateral dislocations (17%) (₄, ₉, ₁₇,₁₈). Lateral dislocations usually occur due to trauma with higher energy and more than 50% of these lesions are open (₁₉). There is a lower frequency of posterior and anterior dislocations, representing 2.5% and 1% of all cases, respectively (₁₈). Immediate reduction is important to avoid skin necrosis and peripheral vascular compression (₇,₈, ₁₁,₁₂,₁₆). Closed reduction is possible in most peritalar dislocations (₁,₇,₂₂); however, in around 10% to 20% of cases, open reduction becomes necessary due to soft tissue interposition or due to severe swelling created by the diagnostic delay(₇,₁₁,₁₂,₁₃,₂₁).

Case Report

A 30 year old male presented with neglected medial peritalar dislocation of right ankle, 8 weeks old with sloughing of skin over the talar head. (Fig.1)

Figure 1

Figure 1: Neglected peritalar dislocation of right ankle with sloughing of skin.

The distal neuro-vascular status was intact. Patient had injured his ankle, when he met an accident while riding a bike. Following accident patient developed swelling and deformity of his ankle. Instead of seeking medical help, the patient felt pray to quackery as such diagnosis and treatment was delayed for more than 8 weeks. Radiographs revealed medial peritalar dislocation (Fig 2a-b). Fig. 2a and 2b AP and Lateral Radiodiographs Showing medial peritalar dislocation.

Figure 2

Debridement of wound and open reduction was performed under spinal anesthesia. Fig 3.

Figure 3

The reduction was not stable and was maintained with tibio-calcaneal and talo-navicular pins. Fig 4. Post operative AP and Lateral radiograph.

Figure 4

Post operatively limb was immobilized in a below knee POP cast with a window. Pins and plaster were removed at 6 weeks when partial weight bearing was allowed. Weight bearing was progressed over next 4 weeks when patient was able to bear full weight and without any limp. Patient was followed for 2 years and at the end of 2 years patient was pain free walked normally. However the motion of subtalar joint was restricted. Radiograph of ankle revealed normal vascularity of talus, slight decrease in subtalar space.Fig.5

Figure 5

Figure 5: Lateral radiographs Of both ankle joints for comparison.

Discussion

Literature is replete with case reports of peritalar dislocations; however there is no report of any neglected case as to our knowledge. We present the management and outcome of a neglected medial peritalar dislocation more than 8 weeks old initially mismanaged by a quack. Peritalar dislocation is a rare lesion, caused by a torsional mechanism that usually involves high-energy (₂,₅,₇,₈,₁₅). It mainly affects male subjects at the economically-active age (₈,₁₁,₁₅). Medial peritalar dislocations are most common (₄,₉,₁₈). Lateral, posterior and Anterior dislocations occur less often. 50% to 70% of cases have associated fractures (₁). Most fractures affect talonavicular and subtalar joint surfaces, producing small osteochondral or cartilaginous fragments that may eventually go unnoticed on pre- or post reduction simple X-rays. Those hidden fractures occur in all lateral and posterior dislocations, and in around 12% to 38% of medial dislocations (₁,₁₈,²⁶,²⁷,²⁸,²⁹ ). Early diagnosis, anatomical reduction, stable fixation of peritalar joint fractures, and the resection of small, free osteochondral fragments are decisive factors for the prevention of early posttraumatic arthrosis which, in turn, may cause pain, joint stiffness, and an unsatisfactory final result (₁).

As a treatment form of peritalar dislocation, immediate reduction is important to avoid skin ischemia around the bony prominence and the consequent skin necrosis, besides neurovascular bundle compression. Treatment delay renders the reduction of dislocation difficult, due to capsuloligamentous retraction (₇,₈,₁₁,₁₂,₁₆). Peritalar dislocations usually can be treated with closed reduction under intravenous sedation or general anesthesia (₁,₇,₁₇,₂₂). Open reduction may be needed in around 10% to 20% of cases due to difficulties in performing closed reduction, or when joint incongruity is seen after close reduction (₂,₇,₁₂,₁₃,₂₁,₂₃,29). Joint stability, after reduction of open peritalar dislocations, occurs in approximately 50% of cases (₈). The presence of instability warranted the transient fixation of subtalar, talo-navicular, or calcaneocuboid joints fixation with Kirschner wires. The cause of instability was probably due to higher grade of soft tissue injury or associated intraarticular fractures. In open, peritalar dislocations, instability should be treated with open reduction and transarticular wire fixation to retain the reduction17. Talar avascular necrosis is rare after peritalar dislocation (₂₄,²⁶,²⁷). It usually occurs as a consequence of severe dislocations due to high-energy trauma, with important compromise of soft tissues and higher grade of talar devascularization (₁₅,₂₁,²⁹). Necrosis may occasionally occur in closed injuries. Degenerative signs are frequent on radiographic analysis after peritalar dislocation, although, in most cases, painful symptoms are uncommon (₁, ₂₂,₂₃).