The Hawkins Sign of the Talus: The Impact of Patient Factors on Prediction Accuracy.

BACKGROUND: Osteonecrosis is a complication of talar neck fractures associated with chronic pain and poor functional outcomes. The Hawkins sign, the radiographic presence of subchondral lucency seen in the talar dome 6 to 8 weeks after trauma, is a strong predictor of preserved talar vascularity. This study sought to assess the accuracy of the Hawkins sign in a contemporary cohort and assess factors associated with inaccuracy. METHODS: A retrospective review of talar neck fractures at a level-I trauma center from 2008 to 2016 was conducted. Both the Hawkins sign and osteonecrosis were evaluated on radiographs. The Hawkins sign was determined on the basis of radiographs taken approximately 6 to 8 weeks after injury, whereas osteonecrosis was determined based on radiographs taken throughout follow-up. The Hawkins sign accuracy was assessed using proportions with 95% confidence intervals (CIs), and associations were examined with Fisher exact testing. RESULTS: In total, 105 talar neck fractures were identified. The Hawkins sign was observed in 21 tali, 3 (14% [95% CI, 3% to 36%]) of which later developed osteonecrosis. In the remaining 84 tali without a Hawkins sign, 32 (38% [95% CI, 28% to 49%]) developed osteonecrosis. Of the 3 tali that developed osteonecrosis following observation of the Hawkins sign, all were in patients who smoked. CONCLUSIONS: A positive Hawkins sign may not be a reliable predictor of preserved talar vascularity in all patients. We identified 3 patients with a positive Hawkins sign who developed osteonecrosis, all of whom were smokers. Factors impairing the restoration of microvascular blood supply to the talus may lead to osteonecrosis despite the presence of preserved macrovascular blood flow and an observed Hawkins sign. Further research is needed to understand the factors limiting Hawkins sign accuracy. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Anatomical basis of a pedicled cuboid bone graft based on the lateral tarsal artery for talar avascular necrosis.

PURPOSE: Vascularized pedicled bone-grafting from the cuboid to the talus provides low donor site morbidity and satisfactory outcomes in patients with early-stage talar avascular necrosis. We investigated the anatomy of the rotational vascularized pedicled bone graft from the cuboid. METHODS: 15 embalmed cadaver specimens were perfused with red latex via the popliteal artery. The lateral malleolus was dissected. The course of the lateral tarsal artery and the vascular territory in the cuboid supplied by the lateral tarsal artery were observed. Vessel diameters were measured. RESULTS: The course of the lateral tarsal artery to the cuboid was consistent, and a vascularized pedicle of the lateral tarsal artery was present in all specimens. Mean diameter of the lateral tarsal artery was 1.40 ± 0.12 mm (range 1.67-1.25). Mean length of the vascularized pedicle was 67.15 ± 3.18 mm (range 62.43-74.36). The pedicle bone graft was long enough to reach the bony border of both the lateral and medial malleolus. CONCLUSION: A vascularized pedicled cuboid bone graft based on the lateral tarsal artery has clinical utility for early-stage talar avascular necrosis.

Surgical Treatment of Talar Neck and Body Fractures: Mid-Term Results of 24 Cases. / Operative Versorgung von zentralen Talusfrakturen: Behandlungsergebnisse von 24 Fällen im mittel- bis langfristigen Verlauf.

BACKGROUND: Talar neck and body fractures are rare. Major posttraumatic complications with a potential reduction in the quality of life are arthrosis and necrosis due to the specific vascular supply. The aim of the study was to evaluate mid-term results of surgery for talar fractures of neck and body. Parameters that potentially affected/influenced treatment outcomes were analysed exploratively. METHODS: 24 patients with 24 talar neck and body fractures (Marti type II n = 9, type III n = 12, type IV n = 3) were retrospectively examined for radiological and clinical functional outcomes. The independent parameters evaluated included age (< 40, ≥ 40 years), sex (male, female), general overall extent of injury (polytrauma/multiple injuries/multiple fractures of the extremities, additional injuries to the same foot, isolated talus fracture), soft tissue damage (open, closed), surgical latency (< 6, ≥ 6 h), fracture classification/displacement (undisplaced [= Marti II], displaced [= Marti III, IV]) and fracture type (talar body, neck fracture). The potential influencing parameters were analysed by univariate analyses. RESULTS: With an average follow-up of 8.7 years (1,25 - 16 years) the AOFAS score was 71.4 ± 22.9 points, the Foot Function Index score 35.9 ± 28.3 points; the physical and mental component summary scores of the Short Form 36, version 2, was 43.8 ± 10.9 and 47.4 ± 13.6 points (mean ± standard deviation), respectively. Thus, the patient reported physical health of the patients was slightly reduced compared to the German population, while the mental health remained largely unaffected. Two patients developed partial avascular necrosis (8%), 10 patients developed osteoarthritis (42%). Of the independent parameters, only the general overall extent of injury showed a significant influence on osteoarthritis (p = 0.002). In the evaluation of undisplaced (n = 9) and displaced (n = 15) fractures, surgical treatment after more than 6 hours did not result in a worse outcome. CONCLUSION: The clinical outcome of internal fixation of talar neck and body fractures can be classified as good. In the study group, there was no correlation between the occurrence of arthrosis and the Marti fracture classification.

Talus Fractures: Evaluation and Treatment.

The talus is unique in having a tenuous vascular supply and 57% of its surface covered by articular cartilage. Fractures of the head, neck, or body regions have the potential to compromise nearby joints and impair vascular inflow, necessitating surgical treatment with stable internal fixation in many cases. The widely preferred approach for many talar neck and body fractures is a dual anterior incision technique to achieve an anatomic reduction, with the addition of a medial malleolar osteotomy as needed to visualize the posterior talar body. Percutaneous screw fixation has also demonstrated success in certain patterns. Despite this modern technique, osteonecrosis and osteoarthritis remain common complications. A variety of new treatments for these complications have been proposed, including vascularized autograft, talar replacement, total ankle arthroplasty, and improved salvage techniques, permitting some patients to return to a higher level of function than was previously possible. Despite these advances, functional outcomes remain poor in a subset of severely injured patients, making further research imperative.

A Case of an Aggressive Intraosseous Arteriovenous Malformation in the Lower Extremity: Special Considerations for Diagnosis and Management.

BACKGROUND: Arteriovenous malformations (AVMs) are rare, congenital vascular anomalies. Intraosseous AVMS most frequently arise in the head and neck, with only a small fraction occurring in the extremities. Herein, we report the findings of a combined soft tissue and intraosseous AVM involving the lower extremity of a 13-year-old child. This case highlights the necessity of an interdisciplinary approach for the effective treatment and management of these rare vascular anomalies. CASE DESCRIPTION: A 13-year-old female presented with a 4-year history of intermittent pain and swelling over her right lateral malleolus. The patient was evaluated with radiologic imaging revealing an AVM involving the right distal leg, ankle, and hindfoot with intraosseous involvement of the distal tibia and talus. She was then referred to Vascular and Plastic Surgery and an angiogram was performed demonstrating shunting from the anterior tibial, peroneal, and posterior tibial arteries to the AVM. Venous drainage was to the anterior tibial and greater saphenous veins. Three embolizations were performed over the course of 6 months. Following the third embolization, the patient was taken to the operating room where Plastic and Orthopedic Surgery performed total resection of the nidus and involved bone which was then grafted with injectable synthetic bone graft. RESULTS: Successful resection of the nidus was achieved, and the patient had an uncomplicated recovery. Within 6 months postoperatively, the patient demonstrated full range of lower extremity motion and was able to participate in age appropriate gross motor activities. Radiologic evaluation 7 months postoperatively showed no evidence of nidus recurrence. CONCLUSION: Intraosseous involvement of AVMS is rare and presents a therapeutic challenge due to its invasive potential and high incidence of recurrence. Wide local excision with bone grafting and interdisciplinary management are paramount for complete resection.

Vascular foramina of talus: an anatomical study with reference to surgical dissection.

PURPOSE: To study the distribution and morphometry of vascular foramina of adult human talus in Indian population. METHODS: The study was carried out by using 56 adult human tali. The location, size, number and foraminal index of vascular foramina on head, neck and body of each bone were examined macroscopically. The difference in location of vascular foramina was further studied in relation to the pattern of calcaneal articular facets on talus. RESULTS: The vascular foramina were present on the superior neck, inferior neck and medial surface of talar body in all (100%) the bones. The Kruskal-Wallis test followed by series of Mann-Whitney test for post hoc analysis showed the number of vascular foramina was significantly greater on inferior surface of neck and medial surface of body. The number of vascular foramina ranged from 0 to 25. About 77.05% of foramina were ≥ 0.5 mm in size. The mean foraminal index of the closest foramina on inferior surface of neck and medial surface of body was 47.90% and 37.23%, respectively. The mean foraminal index of the farthest foramina on inferior surface of neck and medial surface of body was 75.08% and 71.35%, respectively. CONCLUSION: The present study has provided additional information on the vascular foramina of tali. This knowledge is important to the orthopedic, vascular and podiatric surgeons while performing the surgeries of hind foot. We opine that the lateral approach would be more beneficial in the surgical procedures to talus.

Posttraumatic Avascular Necrosis After Proximal Femur, Proximal Humerus, Talar Neck, and Scaphoid Fractures.

Posttraumatic avascular necrosis (AVN) is osteonecrosis from vascular disruption, commonly encountered after fractures of the femoral neck, proximal humerus, talar neck, and scaphoid. These locations have a tenuous vascular supply; the diagnosis, risk factors, natural history, and treatment are reviewed. Fracture nonunion only correlates with AVN in the scaphoid. In the femoral head, the risk is increased for displaced fractures, but the time to surgery and open versus closed treatment do not seem to influence the risk. Patients with collapse are frequently symptomatic, and total hip arthroplasty is the most reliable treatment. In the humeral head, certain fracture patterns correlate with avascularity at the time of injury, but most do not go on to develop AVN due to head revascularization. Additionally, newer surgical approaches and improved construct stability appear to lessen the risk of AVN. The likelihood of AVN of the talar body rises with increased severity of talar injury. The development of AVN corresponds with a worse prognosis and increases the likelihood of secondary procedures. In proximal pole scaphoid fractures, delays in diagnosis and treatment elevate the risk of AVN, which is often seen in cases of nonunion. The need for vascularized versus nonvascularized bone grafting when repairing scaphoid nonunions with AVN remains unclear.

Subtalar Distraction Arthrodesis.

The subtalar joint can be altered in its anatomy and biomechanical behavior. It is important to know how to assess the talar declination angle in order to assess the deformity at the subtalar joint. Consider a straight posterior approach to the subtalar joint and remain liberal in the use of z-shaped Achilles tendon lengthening. A structural bone graft should be used to elevate the talus. Positioning screws should be used to lock the construct.

Management of Talar Component Subsidence.

Component subsidence has been found to be the top complication that leads to failure of the total ankle arthroplasty (TAA). The cause of subsidence formation is unclear, and is multifactorial. Talar subsidence is more frequently met than tibial subsidence, and the subsequent big bone loss is demanding to handle. As a revision treatment option, neither a revision TAA nor a salvage ankle and/or hindfoot arthrodesis procedure is easy to perform or can obtain a definite outcome. The Salto XT can be used to treat most of the TAA systems available for use in the United States with acceptable short-term outcomes.

Review of Talus Fractures and Surgical Timing.

This review article provides an overview of talus fractures. Special attention is given to the clinical literature that evaluates the timing of surgical management for displaced talus fractures. Several series support delayed definitive fixation for talus fractures, suggesting displaced fractures do not necessitate emergent surgical fixation.

[Analysis of the relevant factors for ischemic necrosis of the talus fracture].

OBJECTIVE: To explore the relationship of the classification of talus fracture and surgery methods with avascular necrosis. METHODS: From March 2009 to November 2013, 78 patients with talus fracture were treated, of them, 43 cases were followed up from 2 to 5 years. There were 27 males and 16 females, aged from 17 to 65 years old with the mean of 38.6 years. Thirty-nine cases had talar neck injury and 4 cases had talar body injury. Different treatments were performed according to different injury conditions. The time from injury to treatment was from 6 to 48 hours. The effect of classification of talus fracture and surgery methods on avascular necrosis was analyzed. RESULTS: In 43 cases,19 cases occurred avascular necrosis, including talar neck fracture of type I in 2 cases, type II in 5 cases, type III in 5 cases, type IV in 5 cases and talar body fracture in 2 cases (combined with talar neck fracture). And 29 patients were treated with operation, there was no statistically significant differences in avascular necrosis with different operations. CONCLUSION: Compared with talar body fracture, talar neck fracture is more easily to develop into avascular necrosis. In the 4 types of talar neck fracture, the possibilities of type III and IV were the most ones.

Outcomes of Talar Neck Fractures: A Systematic Review and Meta-analysis.

OBJECTIVES: To report the rates of osteonecrosis and subtalar arthritis after talar neck fractures and to examine if rates have changed over time. DATA SOURCES: A systematic review and meta-analysis of the English literature was performed using EMBASE, MEDLINE, CENTRAL, and Cochrane in November 2011 and updated in November 2014. STUDY SELECTION: Inclusion criteria were studies examining talar neck fractures that reported talar body osteonecrosis rates as a primary or secondary outcome. Exclusion criteria included case series with <10 patients or >50% pediatric patients, inability to isolate results of talar neck fractures, primary treatment of talar excision or arthrodesis, mean follow-up of <3 months, and non-English literature. DATA EXTRACTION: Basic information was collected including journal, author, year published, level of evidence, number of fractures, and follow-up length. Specific information collected included fracture classifications, timing of interventions, method of treatment, osteonecrosis rates, subtalar arthrosis rates, and method of diagnosis of osteonecrosis. DATA SYNTHESIS: Fixed-effects models were used for meta-analysis. The overall event rate of osteonecrosis was calculated and stratified based on Hawkins classification of the talar neck fractures. Mean rates of subtalar arthritis were calculated for all studies and for studies including >2 years of follow-up. CONCLUSIONS: The overall rate of osteonecrosis was 0.312. Rates for Hawkins' types I-IV were 0.098, 0.274, 0.534, and 0.480, respectively. The mean rate of subtalar arthritis was 0.49 but increased to 0.81 in studies with >2 years of follow-up. Complication rates are high in talar neck fractures, and patients should be counseled accordingly.

Arthroscopic ankle fusion for avascular necrosis of the talus.

BACKGROUND: Avascular necrosis (AVN) of the talus is a painful condition leading to destruction of the ankle-hindfoot complex. Moderate outcomes and high complication rates are reported in small numbers of advanced disease treated with tibiotalocalcaneal fusion, which has the additional disadvantage of sacrificing both the ankle and subtalar joints. The blood supply of the talus is tenuous, and open procedures risk further talar collapse by disrupting extraosseous vessels. This article reports the outcome of arthroscopic ankle fusion for late-stage AVN of the talus. Our hypothesis was that arthroscopic ankle fusion would relieve symptoms of advanced talar AVN, prevent collapse of the talus, and preserve the subtalar joint. METHODS: A cohort study was performed on 16 patients with talar AVN treated with arthroscopic ankle fusion. Our primary outcome was fusion rate. Secondary outcomes included perioperative complications, ongoing pain, and further operative intervention. All radiologic investigations were reported independently by a senior radiologist. The average age of the patients was 53.5 years. The presumed causes of talar AVN were steroids, trauma, hematologic disorders, and alcoholism. The etiology was unknown in 7 patients. One patient was lost to follow-up. RESULTS: Clinical and radiologic fusion at the ankle joint was confirmed in 15 of 15 available patients. Thirteen patients reported resolution of pain at follow-up. Three patients had ongoing pain and underwent a subsequent successful subtalar fusion. CONCLUSIONS: Arthroscopic ankle fusion was a safe and reliable treatment of symptomatic advanced talar AVN. It was a minimally invasive procedure with minimal complication rate, preserving the talus and sparing the subtalar joint. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Fractures of the talus.

The talus is the most proximal bone of the hindfoot that couples the foot to the leg. It is the second most common fracture of the tarsal bones, second in frequency to the calcaneous. However, overall injuries to the talus are relatively rare, and most surgeons have little experience in managing them. This article discusses fractures of the talus, including injuries to the talar neck, body, head, and processes. Although subtalar dislocations and osteochondral injuries are important topics, they are not addressed in this article.

[Association between Hindfoot Alignment and Localisation of Osteochondral Lesions of the Talus]. / Zusammenhang der Rückfußachse mit der Lokalisation von osteochondralen Läsionen am Talus.

BACKGROUND: Osteochondral lesions (OCL) of the talus show a distinct distribution pattern. Vascular, metabolic, idiopathic, and biomechanical factors have been proposed as influencing factors. However, the association of hindfoot alignment and the location of talar OCL is not known. MATERIALS AND METHODS: In 22 patients undergoing autologous osteochondral transplantation for OCL of the talus we collected preoperative data on radiographic hindfoot alignment and clinical performance using the AOFAS score and the VAS for pain. The inter-observer reliability between two investigators was calculated. The association between hindfoot alignment and OCL location was statistically assessed. RESULTS: The preoperative AOFAS score was 64.1 ± 13.9 points and the VAS 5.1 ± 1.4. The mean measurement difference between the two observers was less than 0.5 degrees and the reliability of the measurements was good with a high association (κ = 0.83). Surprisingly, the location of the OCL of the talus was independent from hindfoot alignment (p = 0.766). CONCLUSION: In our study the hindfoot alignment showed no association with the location of OCL of the talus. Hence, hindfoot alignment per se does not correlate with the localisation of talar OCL.

Risks to the blood supply of the talus with four methods of total ankle arthroplasty: a cadaveric injection study.

BACKGROUND: Despite the use of contemporary total ankle arthroplasty implant designs, clinical outcomes of total ankle arthroplasty continue to lag behind those of other joint replacement procedures. Disruption of the extraosseous talar blood supply at the time of ankle replacement may be a factor contributing to talar component subsidence-a common mechanism of early failure following ankle replacement. We evaluated the risk of injury to specific extraosseous arteries supplying the talus associated with specific total ankle arthroplasty implants. METHODS: Sixteen fresh-frozen through-knee cadaveric specimens were injected with latex and barium sulfate distal to the popliteal trifurcation to visualize the arteries. Four specimens each were prepared for implantation of four contemporary total ankle arthroplasty systems: Scandinavian Total Ankle Replacement (STAR), INBONE II, Salto Talaris, and Trabecular Metal Total Ankle (TMTA). Postoperative computed tomography scans and 6% sodium hypochlorite chemical debridement were used to examine, measure, and document the proximity of the total ankle arthroplasty instrumentation to the extraosseous talar blood supply. RESULTS: All four implant types subjected the extraosseous talar blood supply to the risk of injury. The INBONE subtalar drill hole directly transected the artery of the tarsal canal in three of four specimens. The lateral approach for the TMTA transected the first perforator of the peroneal artery in two of four specimens. The STAR caused medial injury to the deltoid branches in all four specimens, whereas the other three systems did not directly affect this supply (p < 0.005). The Salto Talaris and STAR implants caused injury to the artery of the tarsal canal in one of four specimens. CONCLUSIONS: All four total ankle arthroplasty systems tested posed a risk of injury to the extraosseous talar blood supply, but the risks of injury to specific arteries were higher for specific implants.

Quantitative assessment of the subchondral vascularity of the talar dome: a cadaveric study.

BACKGROUND: The arterial supply to the talus has been extensively studied previously but never to specifically examine the subchondral region of the talar dome, a frequent site of localised pathology. This study aims to analyse and quantify the subchondral vascularity of the talar dome. METHODS: We performed cadaveric arterial injection studies. After processing, the vascularity to the subchondral region of the talar dome was visualised and mapped using three-dimensional computer technology, then quantified and reported using a nine-section anatomical grid. RESULTS: The areas of relative poor perfusion across the talar dome are the posterior/medial, posterior/lateral and middle/medial sections of a nine-section grid. The rest of the subchondral region shows more richly vascularised bone. CONCLUSIONS: The vascularity of the subchondral surface of the talar dome is not uniformly distributed. This may be relevant to the aetiology and management of osteochondral lesions and shows some correlation with their more frequent locations.

The microvascular anatomy of the talus: a plastination study on the influence of total ankle replacement.

PURPOSE: The purpose of our study was to systematize the arterial supply of the talus and characterize the vessel damage occurring in the talus after total ankle replacement. Previous studies exist using vascular injection to visualize the topic [Giebel et al. (Surg Radiol Anat 19:231-235, 1997); Mulfinger and Trueta (J Bone Joint Surg Br 52:160-167, 1970); Peterson et al. (Acta Orthop Scand 46:1026-1034, 1975); Peterson and Goldie (Acta Orthop Scand 45:260-270, 1974)]. The vascularization of the talus has previously been described by various authors [Aquino et al. (J Foot Surg 25:188-193, 1986); Haliburton et al. (J Bone Joint Surg Am 40:1115-1120, 1958); Mulfinger and Trueta (1970); Peterson et al. (1975); Wildenauer (Z Orthop Ihre Grenzgeb 113:730, 1975)]. The plastination method provides excellent intraosseous view of the arterial system and offers a helpful method to demonstrate the influence of the Scandinavian Total Ankle Replacement (STAR) on the blood vessels. METHODS: In a first step, the nutritive foramina were analyzed on 20 macerated cadaver feet. After this, the articular surface was measured with a print using Optosil. The next step was the visualization of the vascularization of the talus using the plastination method. After vascular injection, a STAR was implanted in two specimens and a plastination was done. RESULTS: The highest amount and density of nutritive foramina were found in the sulcus tali. Using the imprint technique for the examined tali, we found a mean area covered by cartilage of 56.9% in comparison to the total surface. The deep fin of STAR has the potential to eliminate important blood vessels of the talus. CONCLUSION: The plastination methods were useful methods to analyze the arterial supply of the talus. In our study, the STAR showed a dominant influence on the vascularization of the talus. The fin appeared to be too long. A design modification with a short fin could provide the arterial supply, but should be tested biomechanically.

Vascular disruption of the talus: comparison of two approaches for triple arthrodesis.

BACKGROUND: For triple arthrodesis, a single medial incision has been proposed to avoid lateral wound complications and has demonstrated satisfactory fusion rates. This study aimed to compare the disruption to the arterial supply of the talus between the single-medial-incision approach and the 2-incision approach. METHODS: The 2 approaches for triple arthrodesis were compared by analyzing the disruption of arterial vasculature in 14 cadaveric specimens in randomized fashion. The arterial disruption was determined using CT angiography before and after surgery combined with analysis from dissection. The area of joint preparation from each technique was also analyzed and compared. RESULTS: The single-medial-incision approach caused a high incidence of damage to the deltoid artery (6 of 7 specimens, 86%) and the artery of the tarsal canal (7 of 7 specimens, 100%). The 2-incision approach resulted in damage to the artery of the tarsal sinus in all specimens (7 of 7 specimens, 100%), but the medial vasculature was spared given the limited dissection required to access the talonavicular joint. Through the single-medial-incision approach the percentage of debridement of the calcaneocuboid joint (36%) was significantly lower than the debridement using the 2-incision approach (85%, P < .01). There was no significant difference in joint preparation of the talonavicular and subtalar joints between the 2 approaches with the number of specimens available. CONCLUSION: From this cadaveric study, we found that both approaches could result in substantial disruption of the main blood supply to the talus. The single-medial-incision approach consistently disrupted the majority of blood supply to the talar body, while the 2-incision approach caused various degrees of vascular disruption to the talar head and neck. Using the single-medial-incision approach, the calcaneocuboid joint did not show adequate removal of articular cartilage due to difficulty accessing the joint surfaces. CLINICAL RELEVANCE: Vascular sparing to the talus should be considered when selecting an appropriate operative approach for triple arthrodesis. Although the clinical significance of this cadaveric study is limited, the 2-incision approach appeared to cause less vascular disruption to the talar body while allowing more complete joint preparation.

Fractures of the talus: a comprehensive review.

The talus, a highly specialized bone with a unique anatomic design, is crucial for normal ambulation. Although uncommon, talar fractures can be potentially devastating to the patient. Although all talar fractures require appropriate diagnosis and treatment, some require surgical skill for appropriate correction. This article reviews the literature on talar fractures and their treatments.