The complex anatomy of the posterior process talus is comprised of the medial and lateral tubercles. Posterior talar fractures usually involve an isolated fracture of either the medial or lateral tubercle and rarely entail simultaneous fracture of the medial and lateral tubercles (entire posterior process fracture). It is not unheard of that posterior process talus fractures can be overlooked, unless the evaluating surgeon maintains a high index of suspicion for the injury. Isolated medial or lateral tubercle fractures can be more difficult to identify than entire posterior process fractures, because the latter creates a larger fracture fragment that may be more easily seen on standard radiographs. In any case, computerized tomography(CT) scans are helpful in confirming the diagnosis and guiding treatment.Because the posterior process of the talus involves tibiotalar (posterior ankle) and talocal caneal (posterior facet of the subtalar)joints, even minimal displacement of the fracture fragment can result in substantial joint misalignment and posttraumatic arthritis, even after reasonable treatment has been administered, and for this reason accurate reduction and stable fixation are crucial and recommended. The purpose of this report is to describe a case of total posterior process (medial and lateral tubercles) talus fracture, including operative reduction and fixation of the fracture.
Case Reports
Case1
A 31-year-old man sustained what he described (in other terms) as an inversion and plantar flexion injury of his left ankle during a motorcycle accident, and presented to our emergency department approximately 4 hours after the injury with complaints of left foot pain and swelling and an inability to bear weight on the injured foot. On clinical examination, the author (M.K.S.) identified focal pain upon palpation of the medial malleolus, along with stiffness of the ankle and subtalar joints. There was no evidence of neurovascular compromise involving the left lower extremity, and the gross orientation of the foot and ankle was normal in appearance, except for the edema. Initial radiographic inspection revealed a fragment of bone at the medial aspect of the body of the talus on the anteroposterior (AP) view, and posterior to the body of the talus on the lateral view, and CT revealed a fracture of the entire posterior process of the talus (Fig. 1).
After discussion of treatment options, the patient’s left lower extremity was stabilized in a below-the-knee splint,and the decision was made to subsequently go to the operating room for open reduction and internal fixation (ORIF) of the complete posterior process fracture of the talus.
In the operating room, the patient was regionally anesthetized with 0.5% plain bup ivacaine and intravenous sedation and placed in a prone position, and apneumatic tourniquet was used about the left thigh. Before exsanguination of the left lower extremity, 1 gram of cefazolin was administered intravenously. The posterior aspect of the talus was then approached with a 5-cm longitudinal incision placed medial to the medial margin of the Achilles tendon, which was retracted laterally. The flexor hallucis longus muscle and the posterior tibial neurovascular bundle were then identified and protected by means of careful retraction to the medial aspect of the surgical wound (Fig. 2). The posterior ankle and subtalar joint capsules, contiguous at this location, were incised and reflected, thereby exposing the fracture of the posterior process of the talus, including the medial and lateral tubercles. The fracture was reduced under direct visualization by means of manipulation and dorsiflexion of the ankle and then temporarily stabilized with 2 guide pins (Fig. 2), and the reduction was confirmed with image-intensification fluoroscopy. Definitive fixation was then achieved with a single 3.0-mm headless compression screw (Synthes® 3.0 mm Headless Compression Screw; Synthes, Inc., West Chester, PA) directed from posterior to anterior through the fracture fragment into the body of the talus(Fig. 3). The woundwas then closed in anatomic layers, and the limb stabilizedin a dry, sterile bandage and a below-the-knee posterior splint, and the patient was maintained non-weight bearing with the use of crutches. Skin sutures were removed on the 14th postoperative day and the immobilizing splint was discontinued after 4 weeks, at which time physical therapy consisting of passive and active assisted and resisted ankle range-of-motion exercises was started. At 6 weeks postoperative, weight bearing on the left foot resumed, and by 3 months postoperative the patient was fully ambulatory without restrictionin regular shoes and had resumed his regular activities. At the 9-monthfollow-up visit, the patient displayed a full range of ankle range of motion without limitations, and radiographs (Fig. 4) showed satisfactory bone healing without evidence of traumatic arthritis in either the ankle or subtalar joint.
Case 2
A 59-year-old man presented to our emergency department with left ankle pain and an inability to bear weight after a motor vehicle accident 4 days earlier. He described the position of his ankle at the time of injury as inversion and plantar flexion. On examination there was swelling and ecchymosis localized to the left ankle,which was painful and stiff. The neurovascular status to the left foot and ankle was normal, except for the edema and ecchymosis. Inspection of standard radiograph of the ankle failed to distinctly show evidence of a fracture;however, CT scans revealed an entire posterior process fracture of the body of the talus (Fig. 5). After consideration of treatment options, the decision was made to proceed to the operating room for ORIF of the talus fracture, which was undertaken in a fashion similar to that described for Case 1, although in Case2, headless compression screws were used to stabilize the reduced fracture(Fig. 6). Postoperatively, the patient was managed in the same fashion as that described for Case 1, and at 3 months he displayed a full range of nonpainful ankle and subtalar ranges of motion, and by the 9-monthfollow-up visit, he had returned to his pre-injury activity levels using regular shoe gear.
Discussion
According to previous reports, an entire posterior process talus fracture is a rare injury. In the 2 patients described in this report, forced plantar flexion and inversion of the ankle seemed to lead to this unusual talus fracture, and this is consistent with the observations of previous authors. ORIF has been described as the treatment of choice for posterior process fractures of > 3-mm displacement due to articular involvement, or if the fracture propagates into the body ofthe talus.
The purpose of this report was to present 2 cases that involved the unusual fracture of the entire posterior process of the talus. Both of our patients progressed well without complication after ORIF of the fracture using headless compression screw fixation. Based on our understanding of the existing literature, and our experience with the patients described in this report, we believe that ORIF is the treatment of choice for this injury, in that articular disruption is likely to be associated with the development of traumaticarthritis if the fracture is not satisfactorily reduced and stabilized. In conclusion, we recommend the use of a posteromedial or posterolateral approach,and the use of 1 or 2 headless compression screws for ORIF of displaced entire posterior process fractures of the talus.
由MediCool医库软件 赵婷 徐晶晶 编译
原文来自：Entire Posterior Process Talus Fracture: A Report of Two Cases
The Journal of Foot & Ankle Surgery 51 (2012) 326–329
