Session II - Foot and Ankle

Outcome of a Treatment Protocol for Severe Open Unstable Dislocation of the Ankle

Max Morandi, MD; Alan Rechter, MD; Christopher Coufal, MD; Massimiliano De Paolis, MD, Oregon Health Sciences University, Portland, OR

As a result of a high-energy trauma, dislocations of the tibio-talar joint are associated with severe soft tissue damage. Concomitant open injuries with malleolar or talus fractures can produce additional severe instability. The management of these injuries is controversial. No standardized treatment protocol exists to address, in one stage only, all the different aspects: open joint dislocation, fractures and soft tissue lesions. We have developed a treatment protocol for severely unstable open dislocation of the ankle that consists of an emergency reduction of the ankle, stabilized by an external unilateral fixator at the tibia, calcaneus and 1st metatarsal at 90°, ORIF of all associated fractures, concomitant irrigation and debridement of the soft tissues and early plastic surgery. The stabilization with the external fixator does not interfere with ORIF of malleolar or talar fractures or soft tissues care.

We followed a series of 27 patients with open ankle dislocations, operated on by the same surgeons between 1991 and 1996 at a level I trauma center. All pilon fractures were excluded.

There were 18 men and 9 women, with an average age of 35.7 years (21 - 62); motor vehicle accidents were the major cause, followed by falls. All injuries were open, according to Gustilo's classification 23 III B, 3 III A, and 1 was grade II. Five patients with postero-medial dislocations did not have any concomitant fractures. The remaining 22 had associated fractures of the malleollus and in 4 cases, talar fractures. Twenty-six of our patients required a vascularized free flap with a split thickness skin graft, and one had a split thickness skin graft alone. Intra-operative exam revealed deltold ligament disruption in all dislocations not accompanied by a medial malleolus fracture. No ligaments were repaired in our study. A single unilateral frame was used with two titanium half pins (5 mm. diameter) in the antero-medial surface. One half-pin in the calcaneus and one in the metatarsal bone were placed with the foot dorsiflexed at 90 degrees. Syndesmotic screws were used in 8 patients. Weight bearing was not allowed until frames and syndesmotic screws were removed at 6 weeks postoperative. The patients were then placed in a short-leg cast for a period of 2 weeks and allowed progressive weight bearing. The average number of surgical procedures was 4.1, (2 - 8); hospitalization days varied from 4 to 28. Three patients needed readjustment of the frame.

All patients were followed for an average period of 13 months (9 - 31). Results were determined by a patient questionnaire, clinical examination and post-reduction radiographic evaluation performed by a musculoskeletal radiologist. Findings show that this treatment protocol is effective and successful. Although 26 of 27 patients still reported having some occasional residual pain, only 4 required analgesic stronger than over-the-counter medications; 21 out of 27 regained full motion of the ankle. Twenty-two of 27 returned to work, with only 4 of those having a reduced capacities. Questionnaire responses showed that 22 patients believed that they might lose their leg at the time of injury, and none stated that they would have been better off with an early amputation. Anatomic reduction, as evaluated by post-reduction radiographs, correlated well, but not exclusively, with clinical results. Twenty-one of 27 patients had good anatomic reduction, 3 fair and 3 poor. Clinically, all patients had stable ankles at follow up, except one patient with a poor radiographic score. Four of the 21 patients with good radiographic results and 1 of the 3 patients with poor radiographic scores could not return to work because of the injury. All with fair result returned to work. Functionally, 21 patients regained 20 deg. of dorsi flexion and 45 degrees of plantar flexion. The patient with an unstable ankle reported severe pain, posttraumatic arthritis and valgus instability and was treated with an ankle fusion. There were no cases of osteomyelitis or soft tissue infection. Two patients had calcaneal pin-tract infections resolved with local pin care. No avascular necrosis of the talus could be detected radiographically or with MRN. In conclusion, we have developed and instituted a standardized treatment protocol for high-energy severe open ankle dislocations. We found that open fracture dislocations of the ankle are severe injuries, associated with significant soft tissue damage. In recent years the frequency of this group of injuries may be increasing. Early, aggressive management of the wound is mandatory, with immediate ORIF. Accurate reduction of the tibio-fibular diastases is recommended. Early external fixation simplifies soft tissues management by providing excellent wound access. It is technically rapid and easy, well accepted by the patient, effective in maintaining reduced a severe dislocation prone to instability, with excellent surveillance of the neurovascular status of the limb. Plastic surgery is greatly facilitated by the bony and soft tissue stability the fixator provides for vascularized free flaps and skin grafts. These traumas can be managed with both external and internal fixation, without ligamentous repair, obtaining good results, with the majority of the patients returning to their pre-injury work capabilities.