Avascular Necrosis of the Talus: Diagnosis, Treatment, and Modern Reconstructive Options.

Talar avascular necrosis (AVN) is a devastating condition that frequently follows type III and IV talar neck fractures. As 60% of the talus is covered by hyaline cartilage, its vascular supply is limited and prone to trauma, which may eventually lead to AVN development. Early detection of AVN (Hawkins sign, MRI) is crucial, as it may prevent the development of the irreversible stages III and IV of AVN. Alertness is advised regarding non-obvious conditions that may cause this complication (sub chondroplasty, systemic lupus erythematosus, diabetes mellitus). Although, in stages I-II, AVN may be treated with non-surgical procedures (ESWT therapy, non-weight bearing) or joint-sparing techniques (core drilling, bone marrow aspirate injections), stages III-IV require more advanced procedures, such as joint-sacrificing procedures (hindfoot arthrodesis/ankle arthrodesis), or replacement surgery, including total talar replacement (TTR) or combined total ankle replacement (TAR). The advancement of 3D-printing technology and increased access to implant manufacturing are contributing to a rise in the production rates of third-generation total talar prostheses. As a result, there is a growing frequency of alloplasty procedures and combined total ankle replacement (TAR) surgeries. By performing TTR as opposed to deses, the operator avoids (i) delayed union, (ii) a shortening of the limb, (iii) a lack of mobility, and (iv) the stiffening of adjacent joints, which are the main disadvantages of joint-sacrificing procedures. Simultaneously, TTR and combined TAR offer (i) a brief period of weight-bearing restriction, (ii) quick pain relief, and (iii) preservation of the length of the limb. Here, we summarize the most up-to-date knowledge regarding AVN diagnosis and treatment, with a special focus on the role of TTR.

A rare case of "Hawkins type 3" talar neck fracture in a cat.

Background: Fractures of the talus are relatively infrequently reported in small animals. Furthermore, talar neck fracture in cats seems to be very rare. This case report aims to consider the diagnosis, treatment, and a 7-month follow-up of a cat with a Hawkins type 3 talar fracture treated with a type 1b external skeletal fixator (ESF). Emphasizing on the complexity of the injury, considering treatment options and complications, and comparing them to previous reports on cats and humans. Case Description: A 4.5-year-old mixed-breed cat was diagnosed with a Hawkins type 3 talar fracture. Additionally, there were considerations related to the collateral support of the hock joint. The fracture fragment, i.e., the talar body and parts of the neck, was reduced with pointed reduction forceps through a small medial insition. The fracture was then stabilized with a trans articular type 1b ESF. Based on radiographic fracture assessment, de-staging of the frame was done 8 weeks postoperatively. While complete frame removal was at 12 weeks postoperatively. Seven months after the fracture, the cat was minimally lame when walking, and there was a reduced range of motion in the hock joint compared to the contralateral joint. Conclusion: Based on this case and the four previous cases with talar neck fractures, we cannot conclude, but ESF seems to be a good solution, especially when considering the possibility of disruption to the collateral support of the hock joint in this case.

Treatment of Refractory Osteochondral Lesions of the Talus with a Novel Transmalleolar Drilling Technique: A Case Report.

CASE: A 15-year-old adolescent girl underwent revision surgery for a posteromedial osteochondral lesion of the talus (OLT). To provide anatomic reduction of her lesion, fluoroscopy and ankle arthroscopy facilitated a transmalleolar tunnel for screw fixation. Now, 8 years after surgery, the patient reports high patient satisfaction and pain-free functional use of her ankle. CONCLUSION: A transmalleolar tunnel technique provides an alternative method to treat posteromedial OLT. This minimally invasive procedure allows patients to be spared potential complications from a medial malleolar osteotomy or a posteromedial incision. Most importantly, this case report demonstrates a positive long-term patient outcome.

Talar head fractures: An observational study of 33 talar head fractures derived from the Swedish Fracture Register.

BACKGROUND: Reports in the literature on talar head fractures are rare and limited to case reports and small case series. QUESTIONS/PURPOSES: This study aimed to describe a national cohort of talar head fractures for fracture characteristics, associated injuries, treatment, and reoperations. METHODS: We reviewed all radiographs of patients enrolled in the SFR between 2011 and 2021 showing talar head fractures (AO/OTA 81-A3). We excluded those with talar head avulsion fractures, misclassified, multiple registrations, or with a privacy notice in their medical records. The cohort was reviewed using medical records and radiographs at a minimum 2-year follow-up. RESULTS: The study included 32 patients (33 fractures) ≥18 years of age. The median age was 32 (range 18-65) years, 84 % were men, and the main trauma mechanisms were motor vehicle accidents (28 %) and falls from heights (28 %) and graded as high-energy injuries in 50 % of the cases. 18 (55 %) were displaced and 15 (45 %) had comminuted fractures. 14 talar head fractures (42 %) had multiple injuries to the same foot. 21 patients (66 %) underwent surgical treatment, most commonly with screw fixation. Surgery was performed in 15 of 18 patients with displaced fractures. Four patients were reoperated, one with arthrodesis of the talonavicular joint and three for implant removal. No cases of avascular necrosis were identified. CONCLUSIONS: Talar head fractures are rare and occur mainly in men. They are associated with other foot injuries. Most talar head fractures are treated operatively. In this case series, we did not identify any case of avascular necrosis. LEVELS OF EVIDENCE: IV, retrospective observational cohort study.

Comparison of Arthroscopic Microfracture and Retrograde Subchondral Drilling in the Treatment of Osteochondral Lesions of Talus.

PURPOSE OF THE STUDY: In our study, it was aimed to evaluate the efficacy of microfracture and retrograde subchondral drilling on clinical outcomes in patients who underwent ankle arthroscopy due to osteochondral lesion of medial talus. MATERIAL AND METHODS: Twenty eight patients with osteochondral lesion of talus less than 1.5 cm2 treated with ankle arthroscopy were evaluated retrospectively. Microfracture was performed in 16 patients and retrograde subchondral drilling was performed in 12 patients that there was no loss of integrity in the cartilage layer or cartilage layer is partially preserved during ankle arthroscopy. Postoperative evaluations of the patients were done with Foot and Ankle Ability Measure (FAAM) and results of both group were compared statistically. RESULTS: The mean activities of daily living scale was 93.4±3.2 and sportive activity scale was 90.1±5.7 in the retrograde drilling group. In the micro-fracture group, mean activities of daily living scale was 93.8±4.1 and mean sportive activity scale was 88.9±9.5. No significant difference was found as a result of statistical comparisons of both groups results. DISCUSSION: It has been determined that the size and preservation of the integrity of talar osteochondral lesions are important factors on clinical results. Results of arthroscopic debridement, microfracture and drilization are not good in lesions larger than 1.5 cm2 and lesions with impaired integrity. In our study, depending on the general literature, osteochondral lesions in talus were less than 1.5 cm2 in patients who underwent arthroscopic micro fracture and retrograde drilling. CONCLUSIONS: Both microfracture and retrograde subchondral drilling are effective treatment methods with good clinical results for talar osteochondral lesions less than 1,5cm2 . Retrograde subchondral drilling can be an alternative treatment method with the reliability of clinical results in patients with no loss of the integrity of the cartilage layer or cartilage layer is partially preserved. KEY WORDS: talus, osteochondral lesion, microfracture, subchondral drilling.

Clinical comprehensive of microfracture, autologous chondrocyte implantation, and periosteum-covered iliac bone grafting for Hepple stage IV-V lesions.

Chronic ankle pain significantly impairs daily activities and athletic performance with osteochondral lesions of the talus (OLT) in Hepple stages IV and V, which are often causative factors. This study aimed to assess the efficacy and safety of autologous osteochondral transplantation (AOT) for the treatment of these conditions. This retrospective study was conducted from May 2020 to May 2023 at Cangzhou Traditional Chinese and Western Medicine Combined Hospital, including patients with a diagnosis of Hepple stage IV or V OLT confirmed by magnetic resonance imaging (MRI) and arthroscopy. Surgical interventions involved arthroscopic debridement, followed by AOT or limited arthrotomy based on the location and size of the lesion. Preoperative and postoperative evaluations used the Visual Analog Scale, American Orthopedic Foot and Ankle Society Ankle-Hindfoot Scale, MRI-Based Cartilage Repair Tissue Scoring, and the International Knee Documentation Committee Knee Evaluation Form. Statistical analysis was conducted using paired-sample t tests to compare the preoperative and postoperative data. Twenty patients were included, revealing significant postoperative improvements in Visual Analog Scale, American Orthopedic Foot and Ankle Society, and MRI-based cartilage repair tissue scores (P < .05). The radiographic findings suggested effective cartilage regeneration. No adverse effects were observed in the donor knee sites, as confirmed by the stable pre- and postoperative International Knee Documentation Committee Knee Evaluation Form scores. Recovery of physical abilities was achieved on average within 7.3 weeks for daily activities and 13.4 weeks for sports activities. AOT effectively treats Hepple stage IV-V OLT, improves ankle function, promotes cartilage regrowth, and allows quick resumption of daily and athletic activities without compromising donor-site integrity.

Talar and Calcaneal Coordinate Axes Definitions across Foot Pathologies.

The understanding of foot and ankle biomechanics is improving as new technology provides more detailed information about the motion of foot and ankle bones with biplane fluoroscopy, as well as the ability to analyze the hindfoot under weightbearing conditions with weightbearing computed tomography. Three-dimensional anatomical coordinate systems are necessary to describe the 3D alignment and kinematics of the foot and ankle. The lack of standard coordinate systems across research study sites can significantly alter experimental data analyses used for pre-surgical evaluation and post-operative outcome assessments. Clinical treatment paradigms are changing based on the expanding knowledge of complex pes planovalgus morphologies or progressive collapsing foot deformity, which is present in both neurologic and non-neurologic populations. Four patient cohorts were created from 10 flexible PCFD, 10 rigid PCFD, 10 adult cerebral palsy, and 10 asymptomatic control patients. Six coordinate systems were tested on both the talus and calcaneus for all groups. The aim of this study was to evaluate axes definitions for the subtalar joint across four different patient populations to determine the influence of morphology on the implementation of previously defined coordinate systems. Different morphologic presentations from various pathologies have a substantial impact on coordinate system definitions, given that numerous axes definitions are defined through geometric fits or manual landmark selection. Automated coordinate systems that align with clinically relevant anatomic planes are preferred. Principal component axes are automatic, but do not align with clinically relevant planes and should not be used for such analysis where anatomic planes are critical.

Morphological and morphometric analysis of tarsal bones according to sex.

PURPOSE: Our aim in the study is to measure the area and volume of the tarsal bones and examine the typing of the talus and calcaneus joint surfaces according to sex. METHODS: In our study, the area and volume measurements of 630 tarsal bones and the morphology of the talus/calcaneus were analyzed by transferring thin-section Computed Tomography (CT) images to the 3D Slicer program. RESULTS: The volume and area sizes of the foot bones are calcaneus, talus, cuboid, navicular, medial cuneiform, lateral cuneiform, and intermediate cuneiform, respectively. All area and volume values of males were statistically higher than females (p < 0.05). The right side calcaneus area, intermediate cuneiform area, and lateral cuneiform area values were statistically higher than the left side (p < 0.045, p < 0.044, p < 0.030, respectively). There was no statistical relationship between age and area/volume values (p > 0.05). Three different types were seen in the calcaneus and seven in the talus. The most common type in the calcaneus was B1 (40%), and the least common type was A (27.8%). Regardless of the subgroups, the most common type in the talus was type B (37.8%), while the least common type was E2 (1.1%). CONCLUSION: Although morphometric measurements of tarsal bones differed according to sex, they did not differ according to age. The frequency of occurrence of the types of articular surfaces of the talus and calcaneus varies according to populations. We think that the morphometry and morphology of tarsal bones will contribute to invasive procedures regarding tarsal bones and surrounding structures, and that three-dimensional bone modeling can be used to create educational materials.

En bloc resection and reconstruction using a talar prosthesis for malignant talar bone tumor: a surgical technique.

En bloc resection is required for treatment of intermediate-grade talar tumors with extraosseous extension (Enneking stage 3) and malignant talar tumors without intra-articular invasion (Enneking stages IA and IIA). After resection, reconstruction options include tibiocalcaneal fusion, frozen autograft, and talar prosthesis; however, a talar prosthesis is preferable because it preserves ankle range of motion, does not cause leg length discrepancy, and is associated with good long-term outcomes. To the best of our knowledge, en bloc resection and reconstruction of a malignant talar tumor has not been previously reported in detail. We report a detailed surgical technique for en bloc resection of a malignant talar bone tumor using combined anterior and lateral approaches followed by reconstruction using a talar prosthesis.

Designing and additive manufacturing of talus implant for post-traumatic talus avascular necrosis: a case study.

New technologies in additive manufacturing and patient-specific CT-based custom implant designs make it possible for previously unimaginable salvage and limb-sparing operations a practical reality. This study presents the design and fabrication of a lattice-structured implant for talus replacement surgery. Our primary case involved a young adult patient who had sustained severe damage to the talus, resulting in avascular necrosis and subsequent bone collapse. This condition caused persistent and debilitating pain, leading the medical team to consider amputation of the left foot at the ankle level as a last resort. Instead, we proposed a Ti6Al4V-based patient-specific implant with lattice structure specifically designed for pan-talar fusion. Finite element simulation is conducted to estimate its performance. To ensure its mechanical integrity, uniaxial compression experiments were conducted. The implant was produced using selective laser melting technology, which allowed for precise and accurate construction of the unique lattice structure. The patient underwent regular monitoring for a period of 24 months. At 2-years follow-up the patient successfully returned to activities without complication. The patient's functional status was improved, limb shortening was minimized.

The combined talus and sustentaculum fracture: A case series.

BACKGROUND: The sustentaculum tali is a biomechanically important stabilizer of the hindfoot and contributes to articular congruency of the subtalar joint. Sustentaculum injury associated with a talus fracture has been described infrequently and treatment of this combined injury varies. The purpose of this study was to describe and evaluate the outcomes of the combined talus and sustentaculum fracture. METHODS: Retrospective chart and radiographic review was performed on all talus fractures (n = 436) requiring operative fixation over a 21-year period at a single Level-1 trauma center. All talus fractures with sustentaculum fractures were included. Statistical analysis was performed using Chi-squared and Fishers exact tests where appropriate. RESULTS: Sustentaculum fractures occurred in 6.2 % (n = 27) of patients with talus fractures. Average follow-up was 14 months; 18.5 % were open fractures, 88.8 % were from high-energy mechanisms, and 44.4 % were polytraumas. Diagnosis of the sustentaculum fracture was missed on presenting radiographs in 69.2 % (n = 18). The most common associated talus fracture was a talar neck fracture (40.7 %) and the majority (73.7 %) were Hawkins II. Overall, 40.7 % (n = 11) of the sustentaculum fractures were treated with independent fixation and 7.4 % (n = 2) were treated with acute subtalar arthrodesis. Subtalar post-traumatic osteoarthritis (PTOA) at final follow-up was seen in 23.1 % of combined injuries. Independent sustentaculum fixation did not influence the rate of PTOA or re-operation (p = 0.92, p = 0.91, respectively). CONCLUSION: Talar fractures have an associated sustentaculum fracture in approximately 6 % of cases, especially with Hawkins II fracture-dislocations. Over two-thirds of the associated sustentaculum fractures were missed on presenting radiographs, reiterating the need for heightened awareness and consideration of advanced imaging for all talus fractures. The rate of PTOA following these combined injuries at mean follow-up of 24 months does not exceed established rates after isolated talus fractures. Further research is required to determine the optimal management of the sustentaculum in these combined injuries. LEVEL OF EVIDENCE: IV.

Open total talus dislocation without concomitant malleoli fracture: a case report.

BACKGROUND: Total talus dislocation without ankle (malleoli) fracture is a very rare injury with prevalence of only 0.06% of all dislocations and only 2% of talar injuries, and are usually associated with common complications such as infection, avascular necrosis, and posttraumatic arthritis. The treatment usually involves debridement, reduction, stabilization of the ankle joint, and primary or secondary closure of the wound. CASE PRESENTATION: We present the case of a 40-year-old South Asian woman who was involved in an accident. She was rushed to our hospital, whereby subsequent examination revealed an open total talus dislocation with the talus being exposed in its entirety from a contaminated wound in the medial side. Furthermore, radiograph confirmed total talus dislocation without concomitant malleoli fracture. She was immediately taken to the operating theater whereby debridement and immediate reduction was performed under anesthesia, and the ankle was stabilized with external fixator for about 6 weeks. She is now able to bear weight on the affected ankle with minimal tolerable pain and has normal range of motion of the ankle. CONCLUSIONS: Open total talus dislocation without concomitant malleoli fracture is a rare injury. Reduction of the talus in combination with complete wound debridement potentially successfully avoids infection, provides early revascularization preventing avascular necrosis, and preserves the normal ankle anatomy.

MRI and single-cell RNA sequence results reveal the influence of anterior talofibular ligament injury on osteochondral lesions of the talus.

Anterior talofibular ligament injuries and osteochondral lesions of the talus present unique challenges to orthopedic surgeons. This study aimed to investigate the relevant relationship between them by analyzing the Magnetic resonance imaging (MRI) results of clinical patients and single-cell RNA sequence (scRNA seq) results of healthy talus cartilage to discuss the risk factors. Data from 164 patients from 2018 to 2023 was retrospectively analyzed. The correlation analysis between ATFL injury grade and the Hepple stage of OLT determined by MRI was performed. Publicly available single-cell RNA datasets were collected. Single-cell RNA datasets from five volunteers of healthy talus cartilage were analyzed. ATFL injury grade was relevant with the Hepple stage of OLT (P < 0.05). The results of multivariate logistic regression analysis showed that injured area was the independent influencing factor of the incidence rate and the severity of OLT (P < 0.05). The Hepple stage of OLT was relevant with AOFAS and VAS (P < 0.05). Single-cell RNA sequence results showed that among the 9 subtypes of chondrocytes, the interaction strength between HTC-A and HTC-B is the highest. Their physical interactions are mainly achieved through the CD99 signaling pathway, and factor interactions are mainly achieved through the ANGPTL signaling pathway. Anterior talofibular ligament injury may lead to osteochondral lesions of the talus. Early medical intervention should be carried out for ligament injuries to restore joint stability and avoid cartilage damage.

A matching and localization study of iliac bone graft for repair of talar cartilage injury secondary to lateral ankle instability.

Background: To investigate the search for an Iliac-Talar Grafts on the iliac bone that is morphologically matched to a multiplanar injury lesion of the talus; while utilizing a bone-harvesting guide to ensure precise positioning of the Iliac-Talar Grafts. Methods: A total of twenty-two cases with both talar CT data and iliac CT data were collected from January 2019 to June 2023. One case each of talar deformity injury and bone disease were excluded, resulting in a selection of 20 cases. The medial and lateral target repair areas of the talus were formulated, and virtual surgery was performed by using digital orthopedic technology to locate an iliac-talar restoration on the iliac bone that matched the morphology of the multiplanar injury lesion of the talus. 3D chromatographic deviation analysis was used to assess the accuracy of Iliac-Talar Grafts in terms of morphometric matching and positioning, while personalized iliac bone extraction guides were designed to ensure accurate positioning of the Iliac-Talar Grafts. Results: The best fitting point for repairing the medial talar lesion is determined to be medial to the anterior iliac crest, specifically 2.935 ± 0.365 cm posterior to the anterior superior iliac spine, and 2.550 ± 0.559 cm anterior to the valgus-iliac crest point (VICP). Similarly, for the repair of the lateral talar lesion, the ideal position is found to be lateral to the posterior iliac crest, approximately 2.695 ± 0.640 cm posterior to the valgus-iliac crest point (VICP). Utilizing bone extraction guides enables precise positioning for iliac bone extraction. Conclusion: This study utilizes virtual surgery, 3D chromatographic deviation analysis, and guide plate techniques in digital orthopedics to precisely locate the Iliac-Talar Graft on the iliac bone, matching the morphology of the talar lesion; it provides a new solution for cutting the iliac bone implant that matches the the multifaceted talar lesion to be repaired.

Outcomes of Osteochondral Autologous Transplantation with Ipsilateral Lateral Talar Autograft for Medial Osteochondral Lesions of the Talus.

Background: Osteochondral autologous transplantation (OAT) has been widely used in the treatment of osteochondral lesion of the talus (OLT). Previous studies have reported successful outcomes following the use of osteochondral autogenous grafts from the intercondylar notch of the knee or a non-weight-bearing region of the femoral condyle. However, donor-site morbidity of the knee joint has been observed in several cases. This study aimed to investigate the outcomes and safety of OAT with autografts from the ipsilateral lateral talar articular facet as an alternative donor site for medial OLT. Methods: Among 40 patients who underwent OAT, 29 patients were excluded. Eleven patients who underwent OAT with an osteochondral graft harvested from the ipsilateral lateral talar articular facet from 2011 to 2022 were retrospectively analyzed. The size of OLT was measured on ankle magnetic resonance imaging, including coronal length, sagittal length, depth, and area. Clinical outcomes were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale and a visual analog scale (VAS). Weight-bearing ankle radiographs were obtained postoperatively and at 1 year after surgery. Results: The average follow-up time after surgery was 64.7 months (range, 14-137 months). The average diameter of lesions was 8.8 mm (range, 8-9.9 mm). The average size of lesions was 51.2 mm2 (range, 33.6-71.3 mm2) , and all lesions included subchondral cysts. The average depth of lesions was 7.3 mm (range, 6.2-9.1 mm). Graft sizes ranged from 8 to 10 mm in diameter (8 mm, n = 1; 10 mm, n = 10) All measured clinical outcomes improved postoperatively, including the AOFAS scores (preoperative, 55.4 ± 9.0; 1-year follow-up, 92.1 ± 7.6; p = 0.001) and VAS scores (preoperative, 5.5 ± 0.7; 1-year follow-up, 1.9 ± 0.8; p = 0.001). All weight-bearing ankle radiographs of the graft and donor sites did not reveal arthritic change in the ankle joint, lateral talar dome collapse, and graft-site delayed union or nonunion at 1 year after surgery. Conclusions: For a single medial OLT, harvesting autografts from the ipsilateral lateral talar articular facet without knee donor-site morbidities can be a good alternative in OAT for OLT.

Clinical and radiological outcomes of ankle joint preserving surgical reconstruction for talar neck non-unions-A series of 8 cases.

BACKGROUND: Talar neck non-unions result in significant hindfoot deformity and morbidity and are infrequently reported in the literature. The optimal surgical management for this condition is evolving, with various authors reporting the results of open reduction and internal fixation (ORIF) with bone grafting (BG), ankle fusion and modified Blair fusion. We performed this study to report the clinical and radiological outcomes of a cohort of talar neck non-unions managed by ankle joint preserving reconstruction. METHODS: This was an ambispective study which included 8 patients (7 male and 1 female) with talar neck non-unions. All patients underwent ORIF+BG through dual approaches. Additional medial malleolar osteotomy was done in 2 cases, and calcaneofibular split approach to the subtalar joint in 3. Adjunct subtalar fusion was done in 5 cases. Clinical and radiological evaluation was performed pre- and post-operatively. Functional outcomes were assessed by the Manchester Oxford Foot Questionnaire (MOxFQ). RESULTS: The mean age of patients 32.3 ± 13.1 years. The mean surgical delay was 4.1 ± 1.7 months. As per Zwipp and Rammelt classification of post-traumatic talar deformities, 5 cases were classified as Type 3, 2 were Type 4, and 1 was Type 1. Union was achieved in 7 cases at a mean of 3.4 ± 1.3 months. One case had progressive collapse, which was managed by pantalar arthrodesis. All 3 cases where subtalar fusion was not performed primarily demonstrated subtalar arthrosis, but none required a secondary subtalar fusion. The MOxFQ score from 61.1 ± 10.1 to 41 ± 14.1 postoperatively (P = 0.005). The mean follow-up was 14.6 ± 6.8 months. CONCLUSION: ORIF+BG of the talar neck, with or without subtalar fusion has the potential to achieve solid union, correct the hindfoot deformity and improve functional outcomes. However, larger studies with longer follow-up are needed to evaluate the long-term efficacy of this procedure.

Neglected paediatric talus neck fracture: A successful clinical outcome without post-traumatic complications.

Paediatric talus fracture is an extremely rare type of fracture and occurs due to the structural properties of the elastic cartilage that is resistant to high forces. It has a much lower prevalence than in adults. The axial loading of the talus to the anterior tibia while the ankle is in dorsiflexion is the most common mechanism of talus fractures. Although talus neck fracture is the most common fracture, talus corpus fractures are the second most common. Here we present the case of an adolescent male patient who underwent a successful non-surgical treatment and followup of a neglected talus neck fracture.

Effect of a Percutaneous Screw Guide on Screw Placement for Posterior Talar Fractures.

AIM: This study aimed to evaluate the hypothesis that the utilization of percutaneous screw guides enhances the precision of screw placement in the surgical fixation of talar fractures. METHODS: Computed tomography (CT) scans of ankle joints were obtained from 40 healthy adults and 10 cadaveric specimens between April 2019 and August 2020 at Ningbo No. 6 Hospital. The acquired CT data were imported into Materialise Interactive Medical Image Control System (MIMICS) software for processing. Three-dimensional (3D) digital models of the ankle joints were reconstructed, and relevant anatomical parameters were measured. A percutaneous screw guide (PSG) was designed and fabricated to facilitate accurate screw placement in the posterior talar process. Ten eligible cadaveric ankle joints were selected for further analysis and their 3D models were reconstructed using the MIMICS software. Screw trajectory parameters were then measured and analyzed based on these cadaveric models, forming the model group for comparative analyses. Ten cadaveric specimens were utilized in this study, equally divided into two groups: a guider group (n = 5) and a free-hand group (n = 5). In the guider group, talar posterior process screws were inserted using percutaneous screw guidance. In the free-hand group, screws were inserted into the talar posterior process without guidance. Post-operative CT scans were performed on all specimens. The following parameters were quantitatively compared between the two groups: screw trajectories, entry point distances in specimens with preselected screws, entry point distance trajectories in the 3D model, operation time, frequency of fluoroscopic imaging, and number of drilling attempts. RESULTS: Following the generation of the 3D models from 10 cadavers, a virtual screw was digitally inserted into each model. In the model group, the preselected screw trajectory was oriented towards the medial aspect of the talar neck base, with a cephalad inclination angle (CIA) of 3.1° ± 1.5° in the transverse~plane and a medial diverge angle (MDA) of 12.0° ± 1.4° in the coronal plane. The CIA and MDA of the screw trajectory in the guider group were 2.1° ± 1.7° and 11.2° ± 1.6°, respectively, whereas the CIA and MDA in the free-hand group were 6.0° ± 2.2° and 18.8° ± 1.6°, respectively. Statistical analysis revealed significant differences in both CIA and MDA between the two groups (p < 0.05). Furthermore, the guider group yielded superior outcomes in terms of entry point distance, operation time, fluoroscopic exposure time, and number of drilling attempts compared to the free-hand group (p < 0.05). CONCLUSIONS: Percutaneous screw guidance can improve the accuracy and safety of the posterior process of the talar screws, which can be feasible for percutaneous fixation. Further studies are required to confirm the efficacy and clinical outcomes of percutaneous screw guidance.

Post-traumatic avascular necrosis of the talus.

In this comprehensive case report, we examine a 29-year-old male who suffered a high-energy vehicular accident, resulting in a type III Hawkins fracture of the talus. This specific fracture type is critically associated with a greater than 90% risk of progressing to avascular necrosis (AVN) of the talus, a severe and debilitating condition. Alongside this, the patient sustained fractures of the medial and lateral malleolus. Due to extensive swelling and severe circulatory disorders, an immediate emergency surgical procedure was necessitated, employing nail fixation as a stabilizing intervention. Over the course of 12 months following the surgery, despite routine post-operative imaging including X-rays and computed tomography (CT) scans, the patient continued to experience significant pain and impairment. This condition led to further investigations, culminating in a magnetic resonance imaging (MRI) that revealed an area of 19.8∕20.9 mm of AVN on the talus dome's upper-lateral facet. Interestingly, earlier CT scans had indicated multiple osteitic lesions, but these findings lacked a clear clinical correspondence, presenting a diagnostic challenge. To resolve this ambiguity and to definitively distinguish between necrosis and infection, a targeted histopathological analysis was deemed necessary. This analysis was conducted on a bone fragment extracted during a follow-up surgical procedure for nail removal. The results from this analysis present an area of bone and myeloid tissue necrosis unequivocally confirming the presence of AVN, effectively ruling out osteitis as a potential diagnosis. This critical diagnostic clarification allowed for a shift in therapeutic strategy, enabling the initiation of a more focused and potentially curative treatment regimen.

Prediction of carcass weight using the morphometry of ankle bones in hair goats.

BACGROUND: Morphologic measurements such as body lenght, wither height, heart girth, chest width, body leght, cannon-bone circumference is used to predict carcass weight. For this purpose, estimating carcass weight with measurements of key bones such as ankle bones, which play a significant role in the balance distribution of body weight, seems possible. OBJECTIVES: The aim of this study is to create new regression models for effective carcass weight estimation by using the morphometric data of the talus and calcaneus bones of hair goats. METHODS: Study materials consisted of talus and calcaneus bones obtained from abattoir products of hair goat kids (12-18 months old, 20 female and 20 male) and adult hair goats (36-48 months old, 20 female and 20 male). Morphometric measurements of the talus and calcaneus of each animal were taken by a digital caliper. Using the morphometric measurements, an index and a factor were calculated for each bone. Regression analysis and correlations were examined in IBM SPSS 21 programme. RESULTS: As a result, statistical analysis of GLc, GLt, Bd, Calfactor and Talfactor were statistically significant on predicting carcass weight. CONCLUSION: Specific anatomical structures, such as certain bone measurements, such as talus and calnaneus could serve as indicators of growth performance and also carcass weight performance. In addition new anatomical factors and indices may be produced and new regression methods may be applied with these new parameters to predict carcass weight.