Mechanisms of Injury
Signs and Symptoms
Imaging and other Diagnostic Studies
Surgical and Applied Anatomy
Blood Supply of the Talus
Operative Treatment of Talar Neck and Body Fractures
Operative Treatment of Talar Head and Process Fractures
Management of Adverse Outcomes and Complications
Infection and Skin Necrosis
Outcomes and Complications
Author’s Preferred Treatment of Talus Fractures
Dislocations of and Around the Talus
Author’s Preferred Treatment for Subtalar Dislocation
Total Dislocation of the Talus
Controversies and Future Directions
Surgery is indicated for all displaced talar neck and body fractures. Good-quality ankle radiographs and CT scanning forms the basis for accurate diagnosis and surgical planning. Undisplaced, isolated Hawkins type I fractures can be treated successfully with immobilization in a cast. I prefer to use percutaneous stabilization for type I fractures in multiply injured patients. If cast treatment is used, a below-knee non–weight-bearing cast is applied initially. Following cast application, repeat plain radiographs and CT confirms maintenance of a perfect reduction. If any displacement is noted, the classification of the fracture should be reconsidered and open reduction and internal fixation performed. If cast treatment is successful at maintaining the reduction, the patient is asked to remain nonweight bearing for 6 weeks or until there is some radiographic evidence of healing. Next, the patient is converted to a removable brace to begin active range-of-motion exercises. CT is useful at multiple intervals: To initially confirm that the fracture is undisplaced, to confirm that the reduction has been maintained, and to confirm that union has occurred. Patients are warned against excessive weight-bearing activity until union appears to be complete.
Displaced talar neck and body fractures associated with joint dislocations require prompt reduction. When possible, immediate closed or open reduction of the dislocated joints is performed. An attempt at a closed reduction can be performed under adequate anesthesia. Type III or IV fractures are usually not successfully reduced with closed techniques. If an anatomic closed reduction is accomplished, and the fracture is noncomminuted, internal fixation is inserted using percutaneous techniques to achieve stability and facilitate early mobilization. When percutaneous stabilization is performed, it is important to confirm that the reduction is anatomic, usually via CT scan. An open reduction should be performed if there is any doubt about the quality of the reduction. I typically perform percutaneous reduction with the patient in the prone position and use a minimum of two 4-mm cannulated screws, inserted from posterolateral or posteromedial. The preoperative CT scan, especially the reconstructed views, is used to characterize the obliquity of the fracture and define the ideal screw trajectory perpendicular to the fracture line. A small incision and careful blunt dissection is used to protect the associated neurovascular structures at risk, and to ensure that the screws are sufficiently countersunk.
When open reduction and internal fixation is performed, I prefer an anteromedial approach to visualize the medial aspect of the talar neck as a standard initial approach. A slightly more posterior placement of the skin incision, halfway between the tibialis anterior and posterior tendons, facilitates a medial malleolar osteotomy, when required. In the large majority of fractures, a second approach is performed to confirm an anatomic reduction. An incision extending from the tip of the fibula to the fourth metatarsal base facilitates visualization of the lateral aspect of the fracture and placement of hardware. The lateral side is often less comminuted, and thus, one’s ability to judge the reduction may be improved. The lateral approach is performed in all except the most simple of fracture patterns. Dissection around the sinus tarsi and across the dorsal talar neck is kept to a minimum, and overzealous retraction is avoided, to maintain any soft tissue attachments.
Once the incisions have been made and visualization achieved, accomplishing a reduction is sometimes challenging. A medial distractor combined with a Schanz pin into the talar body is useful for type II fractures, whereas combined medial and lateral distractors and a medial malleolar osteotomy are useful for type III or IV fractures. Reflection of the medial malleolus distally facilitates a much gentler closed reduction compared to direct manipulation and is more likely to preserve the talar blood supply via the deltoid ligament. In talar body fractures, the decision whether a malleolar osteotomy is required is based upon the location of the primary fracture line. Fractures that involve the anterior talar body or are associated with malleolar fractures do not require an osteotomy. I perform an osteotomy for those fractures with involvement of the posterior half of the talar body. Usually the osteotomy is medial, but a fibular osteotomy can aid in fractures with lateral side comminution. It is helpful to predrill the screw fixation holes for the osteotomy before making the cut. I prefer a simple oblique medial malleolar osteotomy, angled approximately 60 degrees to the longitudinal axis of the tibia, intersecting with the articular margin 1 to 2 mm lateral to the medial edge of the articular surface of the plafond. An osteotome is used to complete the cut through the articular surface. This technique seems to facilitate good interdigitation of the fragments at the articular surface; 2.7- or 3.5-mm position screws are then used for fixation to avoid overcompression at the nonarticular margin. Thordarson et al.200 and Alexander and Watson3 describe a step-cut medial malleolar osteotomy for exposure of the talar body which results in uncomplicated healing.
Once the joints are reduced, the fracture margins are debrided of comminution. In many cases, extensive comminution is noted, especially involving the subtalar joint. Thorough visualization of the subtalar joint aids to ensure that all loose fragments and debris have been removed. The fracture reduction can then be fine-tuned until an anatomic alignment is achieved.
With regards to fixation, I prefer to use compression screw techniques to address a noncomminuted talar neck fracture and 2-mm plates or their equivalent to address the comminuted medial or lateral column. Rarely, dual plates are necessary for highly comminuted talar neck fractures. Additional screws can then be inserted perpendicular to the primary fracture line for additional stability. The size of screws used depends upon the size of the talar fragments. Usually 2.7-mm screws are used to stabilize the primary fracture fragments, with smaller 2- or 2.4-mm screws for comminuted fragments. Two-mm plates are easiest to contour to the medial or lateral column. Plate placement close to the plantar surface of the talus allows a longer plate to be used. On the lateral side, a four-hole plate beginning at the talar head cartilage can often be contoured to extend to the anterior surface of the lateral process. Screw insertion should be directed perpendicular to the plate. Good fixation through the plate is usually achieved (Fig. 60-21). Medially, less surface area is available for plate placement, and options may be restricted to a two- or three-hole plate.
When the lateral column is reduced, placement of a screw along the lateral shoulder of bone allows an ideal screw insertion point and facilitates compression across the fracture line. The anterolateral shoulder screw is useful to avoid malalignment and facilitates compression of the fracture on the tension side.
Fixation of talar body fractures is typically easier from the medial side, where an area devoid of cartilage exists at the margin of the deep deltoid ligament insertion on the talus. When this is impossible or additional fracture fragments require fixation, countersunk intra-articular screws or headless screws are required.
Bone defects larger than 1 cm3 are usually grafted primarily. The distal tibia provides a reasonable source of cancellous bone. A simple trephination technique into the metaphysis allows removal of approximately 2 to 3 cc of bone, which can then be impacted into the defect. Larger defects are treated with iliac crest or allograft bone.
Intraoperative fluoroscopic imaging is accomplished by placing the imaging intensifier on the opposite side of the operating table, with free draping of the limb. Imaging aids to confirm an anatomic reduction, and to ensure that hardware is appropriately placed. Lateral views in full dorsiflexion and plantarflexion after fixation can rule out ankle joint impingement. A Canale view confirms the talar reduction, and can rule out talonavicular joint impingement.
Once the reduction is confirmed and the fixation stable, a standard layered wound closure is performed. Following surgery, patients are splinted with the foot in a neutral position for 2 weeks. At that point, compliant patients can begin gentle range-of-motion exercises with the use of a removable cast brace. Multiply injured or noncompliant patients may require a longer period of immobilization. Patients are asked to remain strictly nonweight bearing for the first 6 weeks after surgery, and longer if the fracture is comminuted or bone defects are present. Some degree of restricted weight bearing is usually continued for approximately 3 months following the injury, or until union is confirmed (Fig. 60-31).
Subtalar dislocations without associated fractures are initially treated by an attempted closed reduction. Once reduced, the dislocation is usually stable and no internal fixation is necessary. I obtain a CT scan for all subtalar dislocations once the reduction has been attempted. If the closed reduction has been unsuccessful, CT scan provides useful information regarding any bony obstacles to reduction. Following reduction, the CT scan confirms that an anatomic reduction has been achieved and is also useful to assess whether associated osteochondral fractures require further intervention. Occasionally, osteochondral fragments not visible on plain radiographs lie directly within the subtalar joint and require operative removal to achieve an anatomic articular reduction. Alternatively, bone fragments can be avulsed with ligamentous attachments (i.e., from the tip of the fibula or lateral process of talus) in which case a short period of immobilization (up to 4 weeks) may be helpful to reduce pain, allow some provisional healing, and reduce swelling before beginning mobilization exercises.
When a closed reduction has been successful for a simple dislocation, I prefer the use of a well-padded splint until swelling has receded, followed by the application of a short leg removable brace. Patients are encouraged to actively move the ankle, subtalar, and midtarsal joints after approximately 2 weeks but are advised to continue to wear the brace while weight bearing for approximately 4 to 6 weeks. As a result, the goals of early motion are achieved while maintaining protection from sudden and unexpected inversion and eversion forces.
Open reduction is necessary when closed reduction does not achieve a congruent joint. I have found the need for open reduction to be more common than the 10% to 15% often quoted in the literature. I perform an anteromedial approach in most cases and try to avoid incisions through any region of impending or potential skin necrosis (usually localized directly over the talar head). Impaction fractures are usually treated by disimpaction and reduction, followed by elevation and grafting of the fragments. Soft tissue entrapments are carefully inspected for interposed neurovascular structures, then distracted and released as necessary. The posterior tibial tendon should be protected as much as possible in a lateral dislocation, but despite efforts to preserve the tendon, it may not function normally after the reduction, leading to problems later. Smooth Steinmann pins are sometimes necessary to immobilize the hindfoot when the reduction is not stable because of associated bone fragments. When internal fixation is necessary, I immobilize the foot until the pins are removed (usually 6 weeks later) and then recommend active motion physiotherapy.
Subtalar dislocations have a wide variance in terms of their prognosis. Uncomplicated subtalar dislocations, stable following a closed reduction, have an excellent prognosis with minimal symptoms at long-term follow-up. Limitation of subtalar joint motion is a consistent abnormal finding and may be associated with pain when walking on uneven ground or pain with weather changes.17,65,112,184 Perugia et al.159 reported on 45 patients with subtalar dislocations followed for a mean of 7.5 years in whom the mean ankle and hindfoot functional outcome score was in the good to excellent range. Only one patient in their study required a subtalar arthrodesis.159
Most reviews, however, report a mixture of outcomes following subtalar dislocation. Garofalo et al.57 followed 18 patients for 10 years and reported that 44% had fair or poor results. Ruiz Valdivieso et al.170 followed 17 patients for a mean of 7.9 years. Their results were good in only 6 of 17, and fair or poor in the remaining 11.170 Bibbo et al.9 studied 25 patients from a Level I trauma center. Of the 18 patients who were available for review at a mean of 5 years, 89% demonstrated radiographic changes of ankle arthritis, 89% demonstrated subtalar arthritis, and 72% demonstrated midfoot arthritis. Functional outcome scores were much lower than in the study of Perugia et al.,159 and eight patients required an arthrodesis of the ankle or subtalar joints.9
Certain subtalar dislocations are clearly associated with a worse prognosis. Lancaster et al.,109 in a review of the literature, noted that associated injuries and complications were associated with a worse result. In particular, soft tissue injury, extra-articular fracture, intra-articular fracture, and osteonecrosis were associated with a worse outcome.109 Open fractures are undoubtedly associated with the poorest results. Goldner et al.62 reviewed 15 patients at a mean of 18 years following an open subtalar dislocation. Associated injuries were noted to the tibial nerve in 10 patients, to the posterior tibial tendon in five, and to the posterior tibial artery in five. Seven patients ultimately required arthrodesis due to osteonecrosis or posttraumatic arthritis. They concluded that only fair functional and poor anatomic results can be expected following these severe injuries.62
The mechanism of injury is an important factor in predicting long-term outcome. Inversion dislocations resulting from a low-energy mechanism, such as the “basketball foot,” rarely result in long-term morbidity. Violent mechanisms such as a fall from a height or a motor vehicle collision are much more likely to cause long-term problems. Lateral subtalar dislocations may have a worse outcome compared to medial dislocations, but it is likely that the energy of the mechanism is more important than the direction.35 Associated fractures and articular cartilage damage may also be more common with lateral dislocations.
Osteonecrosis of the talus may develop following peritalar dislocations. Overall, osteonecrosis is uncommon and generally only noted with high-energy and open injuries. Theoretically, the talus is not displaced from the ankle mortise and, therefore, at least some of the blood supply should be preserved. However, Goldner et al.62 noted osteonecrosis in 5 of 15 patients with type III open subtalar dislocations, and Bibbo et al.9 noted osteonecrosis in three patients.
Persistent instability is fortunately uncommon.89,112 The subtalar and talonavicular joints have a substantial degree of intrinsic stability such that early mobilization can usually be undertaken safely and effectively. However, repeat subluxation has been noted when immobilization was discontinued early217 and in patients with generalized joint laxity.89 Subluxation which occurs early may be treated with repeat closed reduction with good results.80
Posttraumatic arthritis is common after a peritalar dislocation. The causes of arthritis include associated fractures, cartilage damage, and potentially unrecognized instability. Arthritis can be noted in the ankle or the midfoot, but is most common in the subtalar joint itself. Reports on the incidence of subtalar arthritis range from as low as 25% to as high as 89%.9,35,80,127,217 Although the subtalar changes that are seen radiographically are not always symptomatic, progression to severe and painful arthritis can only be treated with an arthrodesis.
Total dislocation of the talus is a rare injury, resulting from an extension of the forces causing a subtalar dislocation. An extension of the supination force causing medial subtalar dislocation will result in a total lateral talar dislocation, and an extension of the pronation force causing a lateral subtalar dislocation will result in a total medial talar dislocation (Fig. 60-39).114 The injury is usually associated with some degree of associated fracture in the hindfoot but has been reported without fracture in a rare case of posterior dislocation.164
As with most severe talus fractures and dislocations, complete dislocation of the talus is a devastating injury. Results are complicated by infection, osteonecrosis, and posttraumatic arthritis. Most of the injuries are open. Detenbeck and Kelly38 reported a series of nine cases of complete dislocation of the talus. Eight of the nine eventually required talectomy for control of persistent infection.38
Initial treatment is directed to the soft tissues. An early and thorough debridement of contaminated and nonviable tissue is performed, as well as an urgent reduction of the talus to reduce skin tension. In the limited number of available series, most authors have recommended reduction and preservation of the native talus, with arthrodesis and talectomy reserved for treatment of complications.81,101,120,133,145,169,179 Based upon their results, Detenbeck and Kelly38 recommended excision of the talus and primary tibiocalcaneal arthrodesis. However, Taymaz and Gunal195 report a case treated simply with closed reduction and 6 weeks of immobilization in which the patient had an essentially normal ankle at 9 years of follow-up, demonstrating that the outcome is not universally poor.
In general, an open reduction of the completely dislocated talus is required. Aids to reduction include a calcaneal traction pin or distractor. An anteromedial or anterolateral arthrotomy can be used. Blocks to reduction include the extrinsic tendons, associated fracture fragments, and capsular soft tissues.126 The reduction is frequently unstable, requiring transfixion of the subtalar or talonavicular joints. Immobilization should be continued until soft tissue healing has achieved stability, which is usually at least 6 weeks. Osteonecrosis can be anticipated such that early treatment with a patellar tendon bearing orthosis may be considered. Because of the anticipated development of complications, including osteonecrosis and arthritis, patients should be counseled that reconstructive surgery is likely to be required in the future in the form of arthrodesis of involved and symptomatic joints.