"Locked-Lateral" Calcaneal Fracture-Dislocation Treated with Primary Subtalar Fusion: A Case Report

Prevalence and Predictors of Peroneal Tendon Instability Accompanying Calcaneal Fractures

BACKGROUND

We aimed to find the prevalence of peroneal tendon instability (PTI) accompanying different types of calcaneal fractures and to determine predictors of PTI based on preoperative CT scanning.

METHODS

In a retrospective cross-sectional study, preoperative CT scans of 400 consecutive calcaneal fractures undergoing surgery were reviewed for comminuted fragments in the lateral gutter of the ankle, fractures at the tip of the lateral malleolus, dislocated peroneal tendons, excessive displacement of the lateral calcaneal wall, calcaneal fracture-dislocation, superior peroneal retinaculum (SPR) avulsion fracture (fleck sign), and shape of the retromalleolar groove. The correlation of these variables with intraoperative SPR stress test, defined as the diagnostic criteria for PTI in calcaneal fractures, was evaluated.

RESULTS

In total, 369 patients (mean age, 39 ± 13; range, 11-72 years), with 321 (87.0%) of them male, were included. Among all calcaneal fractures, 67 cases (16.7%) had associated PTI as confirmed intraoperatively by an SPR stress test. A statistically significant association was found between PTI in calcaneal fractures and comminuted fragments in the lateral gutter of the ankle (P = .03), dislocated peroneal tendons (P < .001), calcaneal fracture-dislocation (P < .001), SPR avulsion fracture (P < .001), and Sanders type IV of calcaneal fracture (P = .02). There was no statistically significant relationship between PTI and the mechanism of injury (P = .98), side of fracture (P = .30), uni- or bilateral calcaneal fractures (P = .27), a fracture at the tip of lateral malleolus (P = .69), shape of the retromalleolar groove (P = .78), or excessive displacement of the lateral calcaneal wall (P = .06). The most specific CT finding to predict PTI accompanying calcaneal fractures was calcaneal fracture-dislocation (99.1%).

CONCLUSION

Following calcaneal fracture fixation, PTI was confirmed with intraoperative SPR stress test in one-sixth of cases. With the exception of calcaneal fracture-dislocation, preoperative findings on CT scanning and calcaneal fracture pathoanatomy are insufficient to diagnose PTI accompanying calcaneal fractures.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Closed isolated anterolateral calcaneal dislocation: a case report

Background

Complete isolated calcaneal dislocation, defined as dislocation of talocalcaneal and calcaneocuboid joints with intact talonavicular joint without significant fracture, is an exceedingly rare injury.

Case presentation

A 49-year-old man, after a motor vehicle collision, presented with a closed isolated anterolateral dislocation of the calcaneus associated with fracture of the sustentaculum tali, cuboid, lateral process of the talus, and avulsion fracture of superior peroneal retinaculum. Urgent successful closed reduction was immediately performed in the emergency room under sedation. Two days later, through sinus tarsi approach extended proximally to posterior of the lateral malleolus and distally to the calcaneocuboid joint, peroneal tendons were reduced in the retromalleolar groove and avulsion fracture of the superior peroneal retinaculum was reduced and fixed by a suture anchor. A chondral lesion (6 × 8 mm) was seen in the posterior facet of the calcaneus for that chondroplasty and microfracture were performed. Also, small bony fragments from the cuboid were excised. The reduced calcaneocuboid joint was fixed by two Kirschner wires. In the second stage, 10 days later, through medial approach to the talocalcaneal joint, multiple free bony fragments were excised. Then sustentaculum tali was reduced and fixed using a lag screw. Postoperatively, a non-weight bearing short leg cast was applied for six weeks. The patient had permission to start partial weight bearing 6 weeks after removal of K-wires. Finally, at the 10th postoperative week, he had full weight-bearing without any aid instrument. He was able to return to his regular activities about 6 months after the injury. At 34 months, the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale was 92 from 100. The foot function index percentile was 7% and the visual analogue score for pain was 1.9. The last radiographs revealed normal configuration of talocalcaneal, calcaneocuboid, and talonavicular joints with a little joint space narrowing in posterior part of the subtalar joint.

Conclusion

Patients with isolated anterolateral calcaneal dislocations, even with multiple associated fractures, can have acceptable outcomes, if it is urgently diagnosed and properly managed.

Recognition, Treatment, and Outcome of Calcaneal Fracture-Dislocation

BACKGROUND

Calcaneal fracture-dislocations are rare but potentially disabling injuries that are regularly overlooked at first presentation. To date, only about 50 cases have been reported in the literature.

METHODS

Over a period of 8 years, 10 patients (average age 61.7 years) with acute fracture-dislocations of the calcaneus were treated at 2 level 1 trauma centers. The calcaneocuboid joint was involved in 9 patients. There was a concomitant fracture of the lateral talar process and of the tip of the distal fibula in 7 patients each. Open reduction and internal fixation was performed in 9 of 10 patients via an oblique lateral dislocation approach. One patient underwent primary subtalar fusion. All patients were seen for clinical and radiographic follow-up at an average of 3 years using patient-reported outcome scores.

RESULTS

Anatomic fixation was achieved in all patients as judged by postoperative computed tomographic imaging. In the 9 patients treated with internal fixation, the Foot Function Index averaged 12.8, the EuroQol 5D score averaged 0.89 and the visual analog scale score for patient satisfaction averaged 79.3 at final follow-up. Signs of mild subtalar arthritis were seen in 6 patients. No secondary subtalar fusions were needed.

CONCLUSION

When recognized and treated early, prognosis of calcaneal fracture-dislocation was favorable. A dislocation approach starting over the distal fibula, continuing over the sinus tarsi, and extending toward the calcaneocuboid joint allowed for adequate visualization of the subtalar joint and treatment of all components of the injury.

LEVEL OF EVIDENCE

Level IV, retrospective case series.