Access to the talar dome through the medial posterolateral approach: an anatomical study.

Background: The osteochondral grafting has become a popular procedure for treating challenging talar dome lesions. However, the vast majority are treated through medial malleolus osteotomy. The aim of this study was to determine the posteromedial area of the talus that can be reached without malleolar osteotomy through the posteromedial approach. Study Design: Descriptive laboratory study. Evidence Level 4 Methods: Fifteen human cadaveric ankles were dissected in a standard fashion to expose the posteromedial talar dome. Seven approaches were used on the cadaver's left limb (46.7%). We did not observe any significant difference between the evaluated sides (chi-square test, p = 0.715). Results: On average, 2,09 cm2 (range, 1,72-2,69) of the posteromedial talus dome or 15,27 % (range 12-20) of total talus dome can be accessed without osteotomy. Conclusion: If the osteochondral lesion is within the area accessible through PM approach (mean 2 cm2), as seen on magnetic resonance imaging, it is possible that it can be treated without a medial malleolus osteotomy. Keywords: talus; osteochondral lesions; osteotomy; arthrotomy; surgery

Surgical Treatment of Osteochondral Lesions of the Talar Dome: Review

Background. The relevance of the talar dome osteochondral lesions problem is assosiated with the difficulties of diagnosis, the lack of unified treatment algorythm and the great number of unsatisfactory clinical and functional results. In the last decade, there has been increasing interest in this topic in the literature, which is demonstrated by a great number of publications with series of observations or clinical cases. However, attempts to create the universal algorithm for this group of patients treatment are limited by the low level of existing studies evidence, high frequency of the new data publications, as well as the impossibility of using a number of surgical methods in different countries for legislative or other reasons. The aim is to determine the current state of the problem of the talar dome osteochondral lesions surgical treatment and to identify types of surgical interventions in patients with the studied pathology. Material and methods. 120 international articles published from 2000 to 2021, as well as 18 domestic publications for the period from 2007 to 2021 were selected for the literature analysis. The search for publications was carried out in the PubMed/MedLine and eLibrary databases. Results. The most widespread are surgical interventions aimed at stimulation of the bone marrow, and plastic surgery using osteochondral auto - and allografts. Currently, there is no consensus on the indications for different types of surgical methods, and the previously used indications are being questioned. This determines the need to improve diagnostic and treatment concepts. Conclusion. The studied literature cannot fully answer a number of questions related to the methods of surgical treatment of patients with symptomatic osteochondral lesions of the talar dome and indications for them. A more detailed assessment of the medium- and long-term clinical outcomes of various surgical methods and the development of algorithms for this group of patients treatment, specific for different countries, are needed.

Talar Dome Access Through Posteromedial Surgical Intervals for Fracture Care

Background: Posterior talar body fractures are rare injuries without a consensus surgical approach. This study evaluates the accessible area of the talar dome through 2 posteromedial approach intervals (posteromedial [PM] and modified posteromedial [mPM]) both with and without distraction. Methods: Ten male cadaveric legs (5 matched pairs) were included. A PM approach, between flexor hallucis longus (FHL) and the tibial neurovascular bundle, and an mPM approach, between FHL and Achilles tendon, was performed on each pair. In total, 4 mm of distraction across the tibiotalar joint was applied with the foot held in neutral position. Accessible dome surface area (DSA) was outlined by drilling with a 1.6-mm Kirschner wire with and without distraction. Specimens were explanted and analyzed by micro–computed tomography with 3-dimensional reconstruction. Primary outcomes were total accessible DSA and sagittal plane access at predetermined intervals. Results: The PM approach allowed access to 19.1% of the talar DSA without distraction and 33.1% of the talar dome with distraction ( P < .001). The mPM approach provided access to 20.4% and 35.6% of the talar DSA without and with distraction ( P < .001). Both approaches demonstrated similar sagittal plane access at all intervals except the lateral border of the talus, where the mPM approach provided greater access both without distraction (20.5% vs 4.38%, P = .002) and with distraction (34.3% vs 17.8%, P = .02). Conclusion: The mPM approach, using an interval between FHL and Achilles tendon, provides similar access to the posterior surface of talar dome and better sagittal plane access to the most lateral portion of the dome. The mPM interval provides the advantage of avoiding direct dissection of the tibial nerve or posterior tibial artery. Using an external fixator for distraction can improve talar dome visualization substantially. Level of Evidence: Level V, Cadaveric Study.

Relationship between ankle varus moment during gait and radiographic measurements in patients with medial ankle osteoarthritis

Background Kinetic data obtained during gait can be used to clarify the biomechanical pathogenesis of osteoarthritis of the lower extremity. This study aimed to investigate the difference in ankle varus moment between the varus angulation and medial translation types of medial ankle osteoarthritis, and to identify the radiographic measurements associated with ankle varus moment. Methods Twenty-four consecutive patients [mean age 65.8 (SD) 8.0 years; 9 men and 15 women] with medial ankle osteoarthritis were included. Fourteen and 10 patients had the varus angulation (tibiotalar tilt angle≥3 degrees) and medial translation (tibiotalar tilt angle<3 degrees) types, respectively. All patients underwent three-dimensional gait analysis, and the maximum varus moment of the ankle was recorded. Radiographic measurement included tibial plafond inclination, tibiotalar tilt angle, talar dome inclination, and lateral talo-first metatarsal angle. Comparison between the two types of medial ankle osteoarthritis and the relationship between the maximum ankle varus moment and radiographic measurements were analyzed. Results The mean tibial plafond inclination, tibiotalar tilt angle, talar dome inclination, lateral talo-first metatarsal angle, and maximum ankle varus moment were 6.4 degrees (SD 3.3 degrees), 5.0 degrees (SD 4.6 degrees), 11.4 degrees (SD 5.2 degrees), -6.5 degrees (SD 11.7 degrees), and 0.185 (SD 0.082) Nm/kg, respectively. The varus angulation type showed a greater maximum ankle varus moment than the medial translation type (p = .005). The lateral talo-first metatarsal angle was significantly associated with the maximum ankle varus moment (p = .041) in the multiple regression analysis. Conclusion The varus angulation type of medial ankle osteoarthritis is considered to be more imbalanced biomechanically than the medial displacement type. The lateral talo-first metatarsal angle, being significantly associated with the ankle varus moment, should be considered for correction during motion-preserving surgeries for medial ankle osteoarthritis to restore the biomechanical balance of the ankle.

Accessibility and Thickness of Medial and Lateral Talar Body Cartilage for Treatment of Ankle and Foot Osteochondral Lesions

Background: The purposes of this study were to determine (1) if cartilage thicknesses on the talar dome and medial/lateral surfaces of the talus were similar, (2) whether there was sufficient donor cartilage surface area on the medial and lateral talar surfaces to repair talar dome cartilage injuries of the talus, and (3) whether the cartilage surface could be increased following anterior talofibular ligament (ATFL) and sectioning of the tibionavicular and tibiospring portion of the anterior deltoid. Methods: Medial and lateral approaches were utilized in 8 cadaveric ankles to identify the accessible medial, lateral, and talar dome cartilage surfaces in 3 conditions: (1) intact, (2) ATFL release, and (3) superficial anterior deltoid ligament release. The talus was explanted, and the cartilage areas were digitized with a coordinate measuring machine. Cartilage thickness was quantified using a laser scanner. Results: The mean cartilage thickness was 1.0 ± 0.1 mm in all areas tested. In intact ankles, the medial side of the talus showed a larger total area of available cartilage than the lateral side (152 mm2 vs 133 mm2). ATFL release increased the available cartilage area on the medial and lateral sides to 167 mm2 and 194 mm2, respectively. However, only the lateral talar surface had sufficient circular graft donor cartilage available for autologous osteochondral transplantation (AOT) procedures of the talus. After ATFL and deltoid sectioning, there was an increase in available graft donor cartilage available for AOT procedures. Conclusion: The thickness of the medial and lateral talar cartilage surfaces is very similar to that of the talar dome cartilage surface, which provides evidence that the medial and lateral surfaces may serve as acceptable AOT donor cartilage. The surface area available for AOT donor site grafting was sufficient in the intact state; however, sectioning the ATFL and superficial anterior deltoid ligament increased the overall lateral talar surface area available for circular grafting for an AOT procedure that requires a larger graft. These results support the idea that lateral surfaces of the talus may be used as donor cartilage for an AOT procedure since donor and recipient sites are similar in cartilage thickness, and there is sufficient cartilage surface area available for common lesion sizes in the foot and ankle. Clinical Relevance: This anatomical study investigates the feasibility of talar osteochondral autografts from the medial or lateral talar surfaces exposed with standard approaches. It confirms the similar cartilage thickness of the talar dome and the ability to access up to an 8- to 10-mm donor graft from the lateral side of the talus after ligament release. This knowledge may allow better operative planning for use of these surfaces for osteochondral lesions within the foot and ankle, particularly in certain circumstances of a revision microfracture.