Autologous osteoperiosteal transplantation for cystic osteochondral lesions of the talus: Bone reconstruction is essential.

PURPOSE: Autologous osteoperiosteal transplantation (AOPT) is one of the most feasible and effective techniques for cystic osteochondral lesions of the talus (OLT). However, few reports have been reported about the process of graft-host bone healing and bone articular surface reconstruction, which help us to further understand the actual situation of bone healing and modify surgical methods. METHODS: We retrospectively evaluated 33 osteochondral lesions in 30 patients undertaking AOPT for OLT with subchondral cysts from December 2016 to October 2021. According to CT observation, we used 4 variables to describe the bony articular repair, including the integration of the articular surface, the height of the bone filling, the status of bone union, and the appearance of bone resorption or cystic change. We also analyzed the demographic data and clinical function. Descriptive statistics were used for demographic and clinical variables. Normally distributed data were presented as mean ± SD, and non-normally distributed data were presented as median (Q1, Q3). Associations between these variables and the primary clinical outcomes were examined using t-test or one-way ANOVA test for continuous variables. RESULTS: The patients' mean age was (41.7 ± 14.0) years old and the mean follow-up time was (29.6 ± 17.8) months. The chondral lesion size was (14.3 ± 4.1) mm. The cyst depth was (10.9 ± 3.7) mm. Significant improvements were observed in functional outcomes (according to the numeric rating scale for pain when walking and the American orthopedic foot and ankle society score) between the preoperative and latest follow-up evaluations, from 4.2 ± 2.1 to 2.2 ± 2.0 (p < 0.001), and from 66.8 ± 12.9 to 83.2 ± 10.4, respectively (p < 0.001). The overall satisfaction reached 8.3 of 10 points. All patients returned to sports and their median daily steps reached 8000 steps with 27 (81.8%) patients walking over 6000 steps daily. According to CT observation, "discontinuous bony articular surface and gap > 1 mm" was found in 27 grafts (81.8%), and "below the level of the adjacent articular surface, ≤ 1 mm" in a third of the grafts. Abnormal height of bone filling affected numeric rating scale score (p = 0.049) and American Orthopedic Foot and Ankle Society score (p = 0.027). Of note, bone resorption or cystic changes appeared in up to 13 autografts (39.4%). CONCLUSIONS: AOPT is an effective and acceptable technique for cystic OLT. Bone reconstruction is essential for large cystic OLT. How to get better bony articular reconstruction and avoid cyst recurrence should still be paid more attention.

Total ankle/total talus replacement - Retrospective comparison of surgeon decision relative to three-dimensional joint health assessment.

Treatment of end-stage ankle conditions is a complex challenge in foot and ankle surgery. The talus is prone to issues such as osteoarthritis (OA) and avascular necrosis (AVN). Patient-specific total ankle and total talus replacement (TATTR) procedures have emerged as potential solutions, but the decision to include subtalar arthrodesis in these surgeries is multifaceted. In this study, we aimed to understand the relationship between past surgeon decisions for fusion with TATTR and three-dimensional joint health assessments using preoperative CT data. Twenty-seven TATTR with subtalar fusion and 19 TATTR without subtalar fusion were analyzed. Each patient underwent a bilateral computed tomography scan, which was segmented prior to surgery. Distance mapping of various subtalar regions was performed, and average distance was reported. For better analysis, the sinus tarsi was divided into four sectors and the calcaneus posterior facet into nine sectors. Statistical analysis involved calculating the difference in means between the fused and unfused cases. The fusion group exhibited significant joint space narrowing in the posterolateral aspect of the sinus tarsi (p = 0.021). Conversely, on the posterior facet of the subtalar joint, the fusion group showed significant joint space widening in both the anteromedial (p = 0.025) and middle/medial (p = 0.032) sections. Surgeons' decision to perform subtalar arthrodesis in TATTR procedures often aligns with clinical signs of sinus tarsi impingement, as evidenced by significant changes in joint space measurements. While joint health assessments play a pivotal role, other factors, such as surgeon preference and patient-specific considerations, also influence decision-making.

Total Talus Allograft Transplantation With Subtalar Arthrodesis for Missing Talus: A Report of a Rare Case.

Post-traumatic missing talus is a rare and severe injury that often results in poor functional outcomes, with no consensus on the optimal treatment approach as strategies vary based on injury severity. We present the case of a 44-year-old male who sustained a missing talus following a high-energy motorcycle accident. After initial wound management and application of an external fixator, the patient underwent size-matched, fresh-frozen talus allograft transplantation combined with subtalar fusion. Postoperative radiography and CT confirmed successful transplantation with solid subtalar fusion, although progressive osteonecrosis was noted in the medial shoulder region of the talus. At the two-year follow-up, the patient exhibited limited ankle and hindfoot motion but was able to bear weight and walk without assistance, reporting no pain in his feet and achieving a final American Orthopaedic Foot & Ankle Society hindfoot score of 72. This case underscores the potential of total talar allograft transplantation with subtalar arthrodesis in treating severe talar bone loss or missing talus, although long-term follow-up is necessary to assess the clinical implications of medial talar collapse and the possible need for revision surgery.

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.

An Evidence-Based Update on Fixation Procedures for Acute and Chronic Osteochondral Lesions of the Talus.

Osteochondral lesions of the talus (OLT) involve the subchondral bone and the overlying articular cartilage. Various surgical treatments for these lesions are available, such as bone marrow stimulation (BMS), autologous osteochondral grafting, and fixation of an osteochondral fragment. Treatment choice depends on the condition of the lesion, which includes lesion size, morphology, location, and the presence of cysts. Among the surgical procedures available to date, in situ fixation of the osteochondral fragment has the advantage of restoring the articular surface while preserving the native hyaline cartilage and its subchondral bone. Fixation for OLT has been shown to be clinically successful for the treatment of both acute and chronic lesions. Moreover, the indication for osteochondral fragment fixation is expanding as recent studies have found good clinical outcomes in relatively small-sized lesions. The present article describes the current evidence on fixation for acute and chronic OLT.

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.

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.

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.

Outcomes of cobalt-chrome 3D-printed total talus replacement with and without combined total ankle replacement.

BACKGROUND: Collapse of the talus and peri-talar arthritis pose treatment challenges due to the anatomy and location of the talus as a keystone of the foot and ankle. Custom 3D-printed total talus replacement (TTR) and combined total ankle total talus replacement (TATTR) have emerged as treatment options for these pathologies. However, the safety and efficacy of these implants is unknown due to the limited number of cases and short follow-up durations. METHODS: This was a retrospective study to assess surgical outcomes of patients who underwent a TTR and TATTR with or without subtalar fusion. Patient demographics, intraoperative parameters, device related surgical and non-surgical events, imaging and clinical evaluations, and patient reported outcome (PRO) measures were compiled. RESULTS: A total of 38 patients received a custom 3D-printed implant with mean follow-up time of 22.1 (range: 12-45) months. In this cohort, 7 (18.4 %) required secondary surgery and 3 (7.9 %) required implant removal. Multivariate logistic regression revealed that patient diagnosis of depression was a significant predictor of secondary surgery with an OR 17.50 (p = 0.037). Significant postoperative improvements were observed in the talocalcaneal height (p = 0.005) and talar declination angle (p = 0.013) for the TATTR group. VAS and PROMIS pain interference (PI) scores demonstrated an initial significant improvement in pain, but this improvement did not maintain significance at most recent follow-up. However, there was a significant increase in the PROMIS physical function (PF) scores (p = 0.037) at most recent follow-up. CONCLUSION: These results demonstrate that TTR and TATTR provide significant improvement in post-operative radiographic foot and ankle alignment and physical function at the two-year timepoint. PRO findings suggest that patients are more active after surgery. Surgeons considering proceeding with either of these procedures should counsel patients about pain and functional outcomes as well as realistic expectations in patients with depression. LEVEL OF EVIDENCE: Level 3.

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.

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.

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.

Dysplasia Epiphysealis Hemimelica (Trevor Disease) of the Talus in a Toddler: A Case Report With a Long Follow-up.

Visual AbstractThis is a visual representation of the abstract.

Surgical treatment for medium-sized cystic osteochondral lesions of the talus: Autologous osteoperiosteal transplantation provides better clinical outcomes than bone marrow stimulation when cysts are deeper than 6 mm.

PURPOSE: To compare clinical outcomes of autologous osteoperiosteal transplantation versus bone marrow stimulation (BMS) for medium-sized (100-150 mm2) cystic osteochondral lesions of the talus (OLTs) and assess the correlation between patient demographics and outcomes. It was hypothesised that autologous osteoperiosteal transplantation would provide better clinical outcomes than BMS for medium-sized cystic OLTs. METHODS: Patients who underwent autologous osteoperiosteal transplantation or BMS for medium-sized cystic OLTs between 2014 and 2019 were retrospectively evaluated. According to their characteristics, a 1:1 propensity-score matching was performed and 33 pairs of patients were matched. The visual analogue scale, American Orthopaedic Foot and Ankle Society (AOFAS) score, Foot Ankle Outcome Score (FAOS) and Ankle Activity Score were collected preoperatively and at the last follow-up. In addition, a general linear model analysis was performed between patient demographics and clinical outcomes in two groups separately to detect potential risk factors. RESULTS: Finally, 28 patients in the grafted group and 27 patients in the BMS group completed the follow-up and were enrolled with a mean follow-up period of 63.5 ± 13.9 months. Both groups showed significant improvement in all patient-reported outcomes (p < 0.01). At the final follow-up, no significant differences between groups were found in all postoperative scores except FAOS Pain (p = 0.02). Correlation analysis showed a moderate correlation between cyst depth and the postoperative AOFAS score in the BMS group (r = -0.48, p = 0.01). Based on the regression line, the patients in the BMS group with a cyst deeper than 6 mm showed a lower AOFAS score than the mean score (88.7 ± 9.5) of the grafted group. CONCLUSION: Autologous osteoperiosteal transplantation and BMS are both safe and effective for medium-sized cystic OLTs. However, autologous osteoperiosteal transplantation is expected to provide better clinical outcomes than BMS when the cysts are deeper than 6 mm. LEVEL OF EVIDENCE: Level III.

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.

Weight-Bearing CT for Diseases around the Ankle Joint.

Weight-bearing computed tomography (WBCT) enables acquisition of three-dimensional bony structure images in a physiological weight-bearing position, which is fundamental in understanding the pathologic lesions and deformities of the ankle joint. Over the past decade, researchers have focused on validating and developing WBCT measurements, which has significantly enhanced our knowledge of common foot and ankle diseases. Consequently, understanding the application of WBCT in clinical practice is becoming more important to produce improved outcomes in the treatment of disease around the ankle joint. This review will describe an overview of what is currently being evaluated in foot and ankle surgery using WBCT and where the course of research will be heading in the future.

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.

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.

Regeneration of Osteochondral Lesion of the Talus with Retrograde Drilling Technique: An In Vitro Pilot Study.

Background: Retrograde Drilling (RD) is a surgical technique employed for osteochondral lesions of the talus (OCLTs) to reach the subchondral bone lesion from behind, thus preserving cartilage integrity. The aim of the present pilot study was to set up an in vitro model of OCLTs to evaluate the regenerative potential of biological approaches that could be associated with the RD technique. Methods: For this purpose, an OCLT was created in human osteochondral specimens, to try to mimic the RD technique, and to compare the regenerative potential of two biological treatments. For this purpose, three groups of treatments were performed in vitro: (1) no treatment (empty defect); (2) autologous bone graft (ABG); (3) hyaluronic membrane enriched with autologous bone marrow cells. Tissue viability; production of Collagen I and II, Vascular Endothelial Growth Factor, and Aggrecan; and histological and microCT evaluations were performed after 30 days of culture in normal culture conditions. Results: It was observed that Group 3 showed the highest viability, and Group 2 showed the highest protein production. From a histological and microtomographic point of view, it was possible to appreciate the structure of the morcellized bone with which the defect of Group 2 was filled, while it was not yet possible to observe the deposition of mineralized tissue in Group 3. Conclusions: To conclude, this pilot study shows the feasibility of an alternative in vitro model to evaluate and compare the regenerative potential of two biological scaffolds, trying to mimic the RD technique as much as possible. The tissues remained vital for up to 4 weeks and both ABG and hyaluronic acid-based scaffolds stimulated the release of proteins linked to regenerative processes in comparison to the empty defect group.

T1ρ relaxation mapping in osteochondral lesions of the talus: a non-invasive biomarker for altered biomechanical properties of hyaline cartilage?

BACKGROUND: To evaluate T1ρ relaxation mapping in patients with symptomatic talar osteochondral lesions (OLT) and healthy controls (HC) at rest, with axial loading and traction. METHODS: Participants underwent 3-T ankle magnetic resonance imaging at rest and with 500 N loading and 120 N traction, without axial traction for a subcohort of 17/29 HC. We used a fast low-angle shot sequence with variable spin-lock intervals for monoexponential T1ρ fitting. Cartilage was manually segmented to extract T1ρ values. RESULTS: We studied 29 OLT patients (age 31.7 ± 7.5 years, 15 females, body mass index [BMI] 25.0 ± 3.4 kg/m2) and 29 HC (age 25.2 ± 4.3 years, 17 females, BMI 22.5 ± 2.3 kg/m2. T1ρ values of OLT (50.4 ± 3.4 ms) were higher than those of intact cartilage regions of OLT patients (47.2 ± 3.4 ms; p = 0.003) and matched HC cartilage (48.1 ± 3.3 ms; p = 0.030). Axial loading and traction induced significant T1ρ changes in the intact cartilage regions of patients (loading, mean difference -1.1 ms; traction, mean difference 1.4 ms; p = 0.030 for both) and matched HC cartilage (-2.2 ms, p = 0.003; 2.3 ms, p = 0.030; respectively), but not in the OLT itself (-1.3 ms; p = 0.150; +1.9 ms; p = 0.150; respectively). CONCLUSION: Increased T1ρ values may serve as a biomarker of cartilage degeneration in OLT. The absence of load- and traction-induced T1ρ changes in OLT compared to intact cartilage suggests that T1ρ may reflect altered biomechanical properties of hyaline cartilage. TRIAL REGISTRATION: DRKS, DRKS00024010. Registered 11 January 2021, https://drks.de/search/de/trial/DRKS00024010 . RELEVANCE STATEMENT: T1ρ mapping has the potential to evaluate compositional and biomechanical properties of the talar cartilage and may improve therapeutic decision-making in patients with osteochondral lesions. KEY POINTS: T1ρ values in osteochondral lesions increased compared to intact cartilage. Significant load- and traction-induced T1ρ changes were observed in visually intact regions and in healthy controls but not in osteochondral lesions. T1ρ may serve as an imaging biomarker for biomechanical properties of cartilage.