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Introduction/Purpose: Minimal invasive proximal metatarsal osteotomy (PMO) offers a successful approach for addressing metatarsus adductus while avoiding exposure of all metatarsals, thereby reducing the risk of complications such as wound infections and non-unions. An important hurdle is the absence of direct visualization for precise osteotomy placement. Staying within the tarsometatarsal (TMT) capsule enhances the chances of better union due to improved blood supply, although operating outside the capsule can aid in correcting more significant deformities. Despite having a macroscopic understanding of anatomical locations through specimens, there has been a lack of prior reports on their mapping in fluoroscopic images. Developing such maps could significantly improve the navigational skills of surgeons. This study aims to present heatmaps that illustrate the positions of distal attachments of TMT capsules. Methods: A total of nine specimens below the knee, devoid of any prior bone or joint abnormalities, were thawed a day prior to the experiments. After dissecting the dorsal skin, neurovascular structures, and tendons, only the bones and capsules remained. Flexible wires were placed alongside the distal edges of TMT capsules, encompassing the 1st, 2nd, 3rd, and 4th tarsometatarsal joints. This arrangement aimed to make the paths of these capsules visible when observed through X-ray imaging. The wires were then securely attached to the structures using a soft tissue adhesive. Fluoroscopy images were captured, including a calibration marker of a known diameter, in addition to taking macroscopic photographs. The specific coordinates of these structures were marked in a three-dimensional space within specialized 3D software. Subsequently, these coordinates were imported into a custom-designed Python script crafted for the purpose of generating heatmaps. Results: The heatmaps were successfully produced encompassing all TMT capsules spanning from the 1st to the 4th, and these were overlaid onto an anteroposterior fluoroscopy image of the foot (refer to Figure 1). This gradient of colors serves as a visual representation of differing magnitudes, with red denoting the most prevalent areas of the distal attachment of the TMT capsule, while blue corresponds to lower occurrences. Conclusion: These heatmaps not only showcase the predominantly observed sites of distal TMT attachments, depicted in red, but also signify diverse deviations, identifiable by the presence of less frequent zones indicated in blue. Consequently, surgeons are advised to consider these findings while planning their osteotomies based on their preferred positions. By furnishing surgeons with an extensive heatmap that outlines potential tarsometatarsal capsule insertions, this research not only furnishes them with a dependable guiding resource but also establishes a foundation for more assured and prosperous minimally invasive midfoot fusion procedures. Figure 1: The heatmap of 1st to 4th tarsometatarsal capsules on AP fluoroscopy.

Introduction/Purpose: Minimally invasive surgical (MIS) techniques for are exponentially increasing as a surgical option for treating midfoot and forefoot conditions. However, performing percutaneous osteotomies using the burr prevents direct visualization to estimate the correct measurements for the resection. This study aimed to evaluate the impact of each burr pass on the degree of correction, gap size, and alignment in MIS Akin and first metatarsal dorsiflexion osteotomies (DFO). It is hoped that this will improve the surgeon's ability to correct the desired amount of deformity and assist in surgical planning. Methods: Minimally invasive Akin and first metatarsal DFO were performed on ten cadaveric specimens using a 2 mm Shannon burr. The lateral (for Akin) and plantar (for 1st DFO) cortices were left intact. A total of 5 passes with the Shannon burr were performed during each osteotomy. The osteotomy gap was manually closed after each pass and held closed while completing the subsequent passes. Fluoroscopy images were obtained before and after each of the five passes, on which two independent reviewers performed measurements and inter-observer reliability was evaluated with ICC analysis. Measurements included the metatarsal dorsiflexion angle (MDA) and dorsal cortical length (MDCL). Likewise, the phalangeal measurements included the first phalangeal medial cortical length (PCML) and proximal to distal phalangeal articular angle (PDPAA) (Figure 1). Results: The average decrease in PCML with each burr pass was as follows: 1.53 mm at the 1st pass, 1.33 mm at the 2nd pass, 1.27 mm at the 3rd pass, 1.23 mm at the 4th pass, and 1.13 mm at the 5th pass. The MDCL sequentially decreased by 1.80 mm, 1.59 mm, 1.35 mm, 0.75 mm, and 0.60 mm. The MDA consistently decreased, and the PDPAA incrementally became more valgus oriented following each consecutive burr pass. Interobserver reliability analysis demonstrated good agreement for all parameters. Conclusion: The results revealed the length and alignment changes trends in the forefoot and midfoot osteotomies with each burr pass. On average, a first metatarsal dorsal wedge resection of 4.7 mm and first phalangeal medial wedge resection of 2.9 mm was achieved after 3 and 2 burr passes, respectively. The first burr pass provided a correction of 76% of the burr diameter, while it decreased to 66%, 63%, 61%, and 56% of the burr diameter with each subsequent pass. This data may aid surgeons determine the optimal number of burr passes required for the amount of resection needed. Overview of the radiographic measurements. A) first metatarsal dorsiflexion angle (MDA), B) first metatarsal dorsal cortical length (MDCL), C) first phalangeal medial cortical length (PCML) and D) proximal to distal phalangeal articular angle (PDPAA). The diameter of the sphere © The Author(s) 2024(Dsphere) was calculated automatically by the MATLAB script for calibration purposes.

Category: Ankle; Trauma Introduction/Purpose: Chaput tubercle fractures, which are thought to represent tibial-sided avulsions of the anterior inferior tibiofibular ligament (AITFL), are prevalent in up to 30% of trimalleolar ankle fractures. The optimal treatment of small Chaput avulsions is debatable; direct fixation with suture anchor devices and indirect (syndesmotic) fixation are considered as viable options, with proponents on both sides. Moreover, recent literature highlights the potential anatomical alterations to the incisura tibialis resulting from malreduction of large Chaput fragments, furthering the case for direct fixation. Hence, we performed a CT- based three-dimensional fracture mapping study to identify the morphological characteristics of these fractures, and to determine whether they consistently involve the AITFL, tibial plafond and incisura tibialis. Methods: This study included adult patients who had an ankle fracture with a Chaput component; the scheme described by Rammelt et al. was used to classify these fractures. CT scans were obtained, and 3D models were generated. The models were superimposed over a statistical shape model of the right tibia which served as a template and fracture lines were marked. The footprints of proximal and main bands of the AITFL and Basset’s ligament were also marked on the template tibia. The tibial template along with the fracture lines was then imported into MATLAB, and an automated script was used to determine the fragment size (length, breadth, and height), fracture surface area, involvement of the tibial plafond, tibial incisura, and the anterior inferior tibiofibular ligament (AITFL) and Basset’s ligament. Fracture maps and heat maps were generated. Agglomerative cluster analysis using Ward’s linkage was used to identify discrete fracture categories. Results: 76 patients, 21 males and 55 females were included in this study. Cluster analysis identified two distinct groups of fractures, each with two unique subgroups. We present this as a modification of the existing classification system. The first group, corresponded to Rammelt Type 1 fractures (sub centimetric extra-articular avulsion fractures, n=47). Of these, 19% (n=9) did not involve the AITFL, which we termed as Type 1a, and 91% (n=48) involved the AITFL, which we termed as Type 1b. The second group consisted of large intra-articular fractures that corresponded to Rammelt Type 2 injuries. Of these 23% (n=6) involved only the incisura, which we termed as Type 2a; 77 % involved both the incisura and the tibial plafond and were termed as Type 2b. Conclusion: We propose a modification of the existing classification of Chaput fractures on the basis of quantitative fracture mapping. This study provides new insights into the morphological characteristics of Chaput fractures. 19% of small Chaput fractures do not involve the AITFL and may not require direct fixation. Conversely, all large-sized fragments involve the incisura and necessitate anatomical reduction to achieve accurate syndesmotic reduction. Our proposed modification can aid in surgical decision-making, particularly in choosing between direct and indirect syndesmotic fixation.

Category: Sports; Trauma Introduction/Purpose: Syndesmotic ankle injuries are present in one-fourth of all ankle trauma and may lead to syndesmotic instability or posttraumatic ankle osteoarthirtis on the long term. At present, they continue to impose a diagnostic dilemma our clinical practice. While magnetic resonance imaging lacks application of load to the ankle joint, plain weightbearing radiographs are skewed by superposition of the osseous structures. The recent advent of weightbearing cone-beam CT (WBCT) overcomes these drawbacks by imaging both ankles during bipedal stance. However, it remains debated whether syndesmotic ankle injuries should be imaged under weightbearing conditions and/or during application of external rotation. Therefore, we aimed to implement both weightbearing and external rotation in the assessment of syndesmotic ankle injuries using WBCT imaging combined with 3D measurement techniques. Methods: In this retrospective study, patients with an acute syndesmotic ankle injury were analyzed using a WBCT (N= 21; Age= 31.64±14.07 years old). Inclusion criteria were an MRI confirmed syndesmotic ligament injury imaged by a WBCT of the ankle during weightbearing and combined weightbearing-external rotation. Exclusion criteria consisted of fracture associated syndesmotic injuries. For the external rotation protocol, the patient was asked to internally rotate the shin while ensuring that the foot remained firmly plantigrade until pain (Visual Analogue Scale > 8/10) or a maximal range of motion was reached. 3D models were generated from the CT slices. Tibiofibular displacement and Talar Rotation were quantified by automated 3D measurements using a custom-made Matlab® script; Anterior Tibiofibular distance (ATFD), Alpha angle, posterior Tibiofibular distance (PTFD) and Talar rotation (TR) angle in comparison to the contralateral non-injured ankle. Results: The difference in neutral-stressed Alpha angle and ATFD showed a significant difference between patients with a syndesmotic ankle lesion and contralateral control (P = 0.046 and P = 0.039, respectively). The difference in neutral-stressed PTFD and TR angle did not show a significant difference between patients with a syndesmotic ankle lesion and healthy ankles (P = 0.492; P = 0.152, respectively). Conclusion: Application of combined weightbearing-external rotation reveals an increased ATFD in patients with syndesmotic ligament injuries (Figure 1). This study provides the first insights based on 3D measurements to support the potential relevance of applying external rotation during WBCT imaging. In clinical practice, this could enhance the current diagnostic accuracy of subtle syndesmotic instability in a non-invasive manner. However, future studies are required to determine cut-off values that may indicate the amount of displacement that might lead to chronic instability and require a certain type of treatment strategy.

Category: Trauma; Ankle Introduction/Purpose: Ankle fractures represent an increasingly common injury world-wide and the decision for operative fixation often hinges on the definition of acceptable stability. Mortise malalignment has generally been considered as the main predictive factor leading to poorer outcomes and the development of post-traumatic osteoarthritis. Following pioneering work by Ramsey & Hamilton, 1-2 mm of lateral talar displacement has commonly been regarded as a cutoff value for surgical decision making. However, isolated lateral talar translation (as studied in previous works) does not fully replicate the multidirectional joint subluxation seen in ankle fractures. Furthermore, previous studies have been limited by low fidelity methodologic techniques. Therefore, the aim of this study was to analyze the influence of multiplanar talar displacement on tibiotalar contact mechanics utilizing finite element analysis (FEA). Methods: 19 patients having undergone advanced computed tomography (CT) scanning of the ankle were included. A female patient (age 18 years, weight 60 kg) without preexisting articular ankle pathology underwent a weightbearing CT-arthrogram of the left ankle. Additionally, 18 ankles derived from the contralateral healthy side in patients who underwent bilateral weightbearing CT scans (WBCT ) for evaluation of a contralateral ankle fracture were included (mean age = 38.70 years, mean weight = 80.00 kg, left/right: 9/9). Segmentation of the WBCT images into 3D models of bone and cartilage was performed semi-automatically, while on the non-arthrography WBCT images, personalized cartilage layers were modeled based on a previously validated methodology. 3D multiplanar talar displacement was simulated to investigate their respective influence on the tibiotalar contact mechanics. Tibial peak contact stress, talar peak contact stress and contact area were extracted from the FEA models for each condition. Results: The talar peak contact stress (in MPa), tibial peak contact stress (in MPa) and contact area (in mm²) for each condition are presented in Table 1. Overall, both the mean and peak contact stress for the talus and tibia incrementally increased when the talus was displaced, for all directions. Correspondingly, the contact area incrementally decreased. Contact stress maps of the talus and tibia were computed for each of the conditions, demonstrating unique patterns of pressure derangement. 1 mm of lateral translation resulted in 11% increase in peak contact pressure and a 12% decrease in contact area. External rotation exhibited the greatest influence on contact stress, reaching a peak talar stress of 510% above baseline after 20 degrees of external talar rotation. Conclusion: In this study, we were able to build on the paradigm of prior uniplanar cadaveric studies and provide a multiplanar mortise malalignment model. The use of advanced computational technologies allowed for more precise quantitative evaluation of articular contact mechanics. With lateral talar translation, our model demonstrated less dramatic increases in tibiotalar contact area compared to previous studies, whereas external rotation had the largest effect regarding pathologic joint loading. Clinically, this study provides a novel understanding of the mechanical sequelae of 3D talar displacement and the importance for adequate mortise alignment.

Category: Sports; Ankle Introduction/Purpose: Acute Achilles tendon ruptures (ATRs) can be treated surgically through either open repair or minimally invasive surgical techniques (MIS). While the relative complication rates between these techniques, including wound dehiscence, re-rupture, and sural nerve injury, have been debated, many studies demonstrate no significant difference between these two approaches. In this study, we conducted a Kaplan-Meier survival analysis to compare the incidence and timing of complications between open and MIS repair of acute ATRs and examine factors that may influence these rates. Methods: A retrospective study was conducted to evaluate the outcomes of patients (≥18 years) who underwent surgical intervention for acute ATR within a four-week period following injury, with a minimum follow-up of three months. Data on demographic variables, type of surgical procedure (MIS or open approach), and the occurrence and timing of postoperative complications were collected. Postoperative complications were classified as venous thromboembolism (VTE), re-rupture, surgical site infecti+D2on (SSI), wound dehiscence, and sural nerve injury.The Kaplan-Meier method was employed to compare the complication rates between the MIS and open repair groups. The log-rank test was used to test the equality of survivor functions. The Cox proportional hazards model was employed to determine predictors of complications. Results: In total, 417 patients were included in the final analysis. The MIS group had a higher proportion of patients with tobacco use. Fifty-two complications in 50 patients were recorded (Table 1). We found no significant difference in the complication rates between the MIS and open repair groups. However, Cox proportional hazards modeling revealed that body mass index (BMI) was a significant predictor of re-ruptures (HR 1.2, 95% CI = 1.05–1.4) and that surgical delay was found to be a significant predictor of wound dehiscence (HR 1.2, 95% CI =1.01–1.3) and sural nerve injury (HR 1.2, 95% CI =1.1–1.3). A surgical delay of more than 2 weeks was noted to have a positive likelihood ratio of 2.3 for wound dehiscence and 3.1 for sural nerve injury. Conclusion: The results of this study indicate that MIS and open repair techniques for acute ATRs demonstrate comparable complication rates. However, patients with elevated BMI exhibit an increased risk of re-rupture. Those with surgical delay beyond two weeks have an elevated likelihood of wound dehiscence and sural nerve injury, presumptively due to associated scaring and the requisite tissue manipulation. Surgeons and patients may consider these variables when formulating a surgical treatment plan.

Category: Ankle; Trauma Introduction/Purpose: Approximately 10-15% of posterior malleolar fractures (PMFs) are "small shell," extra-articular fragments. Current classification systems present difficulties to perform a uniform typification of PMFs and contain no consensus on whether they should be fixed. Anatomical studies have identified two distinct components of the posterior inferior tibiofibular ligament (PITFL); the superficial band is thought to be more important than its deep counterpart in imparting syndesmotic stability. However, the involvement of one or both bands of the PITFL by small shell PMFs has not been evaluated so far. Hence, we conducted this study to perform 3D mapping of small shell PMFs and to determine whether surgeons should fix these routinely. Methods: Ankle fracture patients with a ‘small shell’ PMF (Haraguchi 3/Mason 1/Bartoníček 1 or 2) were included. Demographics, radiological features, treatment, and outcomes were recorded. 3D models of the fractured tibiae were generated from CT scans and superimposed on a statistical shape model of the right tibia, which served as a template. Fracture lines along with footprints of superficial and deep PITFL were marked on the template. 3D fracture heat maps were generated. Size of the fracture fragments and involvement of the superficial and deep PITFL footprints were quantified using a custom MATLAB script (Figure 1). Sparing of the footprint was defined as an overlap of < 1% between the fracture line and the footprint areas. Odds ratios (OR) with 95% confidence intervals (CI) were determined to determine which variables correlated with sparing of the PITFL footprint; P-values of < 0.05 were considered significant. Results: Thirty-nine patients were included. The superficial PITFL footprint was spared in 15 (38%), deep PITFL in 10 (26%), and both in 4 cases (10%). Males and Weber C fractures had a higher likelihood of sparing the superficial and deep PITFL footprints, respectively (P = 0.04). Supination external rotation (SER) patterns were less likely to demonstrate syndesmotic widening if either PITFL footprint was spared. Direct fixation of the PMF was done in 1 case; syndesmotic fixation in 25 cases and in 14 cases, no syndesmotic fixation was done. Of these, 11 were SER injuries where stability was achieved after fixation of medial and lateral malleoli. In 1 SER and pronation external rotation (PER) injury case, the syndesmosis was stable after fixation of a large Chaput fragment. Conclusion: This study demonstrated that 48% of small shell PMFs spare either the superficial or deep footprint of the PITFL; in 10% both PITFL footprints were spared. Hence, 58 % of small-shell PMFs may not benefit from direct fixation. Additionally, SER injuries with small shell PMFs that spare either PITFL footprint may not demonstrate radiographic instability and may not need direct or indirect fixation after addressing other components of the ankle fracture. However, given the fact that syndesmotic stability is not dictated by the PITFL alone, it remains prudent to stress the syndesmosis per-operatively to determine if syndesmotic fixation is needed.

Category: Hindfoot; Sports Introduction/Purpose: Posterior heel pain at the Achilles tendon insertion is a prevalent and debilitating condition that is not yet fully understood. It results from a combination of bony and soft tissue abnormalities, including insertional Achilles tendinopathy, retrocalcaneal bursitis, and posterosuperior bony prominence. While the most commonly used surgical technique for treatment is debridement and reattachment of the tendon, dorsal closing wedge calcaneal osteotomy (DCWCO) has recently gained popularity. In this meta-analysis, we aimed to analyze the published literature related to both surgical techniques and compare their outcomes. Our hypothesis was that DCWCO can provide similar clinical outcomes with a lower complication rate. Methods: We conducted a literature search in Medline, Embase, and Scopus databases. Clinical studies reporting at least one of the clinical outcomes among AOFAS score and complications, with an open technique and sufficient data to extract and pool, were included. The extraction was made by two users using the Covidence platform. Studies with less than 10 patients or less than 12 months follow-up were excluded. Initial search yielded 329 papers, and after excluding duplicates and irrelevant studies, 43 papers were left. After a full-text review of these 43 papers, we found 15 papers eligible for meta-analysis. We used the Modified Coleman Methodology to assess the quality of papers. Results: Out of the 15 articles, seven included reattachment patients, while eight included DCWCO patients. 171 feet underwent reattachment, while 239 feet underwent DCWCO. The average follow-up of patients was significantly higher in the DCWCO group (42.2 months) than reattachment group (23.2 months). The average AOFAS score improvement was similar between the groups. The total complication numbers were 30 (16.6%) in the reattachment group and 28 (9.2%) in the DCWCO group, but the difference did not reach significance since the confidence intervals were overlapping. However, wound complications were significantly more common in Reattachment group (10.1%) compared to DCWCO (2.5%). The number of revision surgeries and neurological complications (sural neuritis, hypersensitivity, etc.) were similar between the groups. The average AOFAS score improvement was similar between the groups. Conclusion: Both techniques yielded comparable clinical outcomes. The overall complication rate was similar, but DCWCO exhibited a lower wound complication rate than reattachment. Therefore, the study results imply that DCWCO can provide similar clinical outcomes with fewer wound complications. However, further well-designed studies are necessary to reach a definitive conclusion on this matter and compare both techniques in the same study setting.

Category: Hindfoot; Sports Introduction/Purpose: The use of a dorsal closing wedge calcaneal osteotomy (DCWCO) in the treatment of insertional Achilles tendinopathy (IAT) has recently gained popularity. The anatomical changes imposed by the osteotomy are believed to improve both the biological and mechanical processes involved in IAT. However, the impact of shortening the Achilles leverage arm after DCWCO and the full impact of DCWCO on foot anatomy and function is not well understood. This study aimed to examine the effects of DCWCO on the 3D alignment and biomechanics of the foot and ankle in IAT patients through simulated models of DCWCO. The hypothesis was that DCWCO would significantly impact foot alignment and decrease gastrocsoleus lever arm. Methods: Six weightbearing ankle CTs of patients with IAT were identified from the clinical database. Bone segmentation was performed and DCWCOs were conducted in standardized planes with six variations, resulting in a total of 36 foot models. Two plantar osteotomy starting points were defined as 1-cm anterior (posterior osteotomy) and 2-cm anterior (anterior osteotomy) to the most plantar point of calcaneus. The osteotomies were extended to dorsal surface at 1-cm anterior to posterosuperior calcaneus with 6, 10, or 14-mm wedges anteriorly. After the osteotomies, the posterior part of the calcaneus was rotated around the plantar starting point until proper bone contact was achieved. Achilles reconstruction was also performed using pre-defined Achilles insertion points. All models were then transferred to a MATLAB-based algorithm for automated measurements. These measurements included talocalcaneal, calcaneal pitch, Böhler, and Achilles tendon sagittal angles, Achilles moment arm, Achilles- posterosuperior calcaneus distance, and difference in soleus-Achilles length. Results: Anteriorly placed osteotomy caused more significant decrease in the Böhler angle (p < 0.001). Evaluation of the posteriorly placed osteotomy separately showed no significant decrease in the Böhler angle for patients with more than 30- degrees of preoperative Böhler angle (p=0.26). However, patients with a preoperative Böhler angle less than 30-degrees showed a significant decrease, approaching values close to 5-degrees (p=0.004). Gastrocsoleus moment arm decrease was found to be 2-3% by using force/moment equation. The change in the distance between Achilles tendon and the posterosuperior calcaneus was similar between anterior and posterior osteotomies, with less than 3-mm in a 6-mm wedge and more than 5-mm in a 10-mm wedge osteotomy. The calculations showed that ankle dorsiflexion can increase by one degree for each mm of resection. Conclusion: An anteriorly placed starting point for a DCWCO can negatively affect foot alignment and offer limited benefits for Achilles decompression. If the preoperative Böhler angle is less than 30, a DCWCO can significantly decrease the Böhler angle, potentially putting the subtalar joint at risk for arthritis by increasing the load as reported by some finite element studies. The maximum decrease in gastrocsoleus power is less than 3%, which may be clinically insignificant. A posterior starting point with 10- mm wedge can be adequate to move Haglund around 5-mm anteriorly and can move Achilles insertion 10-mm superiorly to decrease tension.

Category: Trauma; Ankle Introduction/Purpose: Weber-B ankle fractures represent an increasingly common injury world-wide, and the decision for operative fixation often hinges on the stability and congruency of the ankle. While tibiotalar displacement is typically evaluated using the medial clear space on plain radiographs, this method remains prone to inaccuracy because of x-ray beam rotation and manual measurement errors. Furthermore, the influence of these fractures on the mechanical environment of the ankle remains unknown. The recent advent of weightbearing cone-beam CT (WBCT) overcomes these drawbacks by imaging during bipedal stance, allowing a 3D anatomical and mechanical analysis. Therefore, the aim of this study was to analyze the 3D mortise displacement and contact mechanics in weber B ankle fractures by use of WBCT in comparison to their healthy contralateral side. Methods: In this retrospective study, our ankle trauma database was searched for Weber-B ankle fractures imaged by bilateral WBCT imaging between 2015 and 2022. Exclusion criteria consisted of metal or motion artifacts, presence of ankle osteoarthritis, and an age less than 18 years or more than 75 years. Segmentation into 3D models of bone was performed semi-automatically, while personalized cartilage layers were modeled based on a previously validated methodology. Bilateral ankle models were imported in custom-made Matlab® script for an automated anatomical and mechanical analysis. 3D mortise congruency was evaluated by use of following parameters: fibular length, talocrural angle, distance mapping of the medial gutter and tibiofibular clear space distance mapping. Contact mechanics were evaluated by the mean and maximum contact stress of the tibia and talus, as well as the contact area (Figure 1). A student’s T-test was performed to investigate the difference between the fractured and healthy side. Results: Thirty-two patients, with mean age 38.50 years (SD = 15.81 ) and weight 79.12 kg (SD = 16,24), were confirmed eligible for analysis. Statistical analysis revealed that there were no significant differences for all anatomical parameters (P > 0.05). The mean contact stress of the fractured and healthy side was 2.10 (SD = 0.42) MPa and 2.10 (SD = 0,41) MPa, respectively, whereas the maximum stress was 7.67 MPa (SD = 1.55) and 7,47 MPa (SD = 1,67), respectively. No statistical significant differences were found between all mechanical parameters (P > 0.05). Conclusion: This study demonstrates that contact mechanics are not affected in Weber-B fractures with a congruent mortise. Therefore, non-operative treatment could be considered, as there will theoretically be no increased risk for the patients to develop posttraumatic osteoarthritis in the long term. In clinical practice, WBCT could prove useful to determine the 3D anatomical and mechanical environment of ankle fractures and guide patients towards (non-) operative treatment. However, further studies should focus on the minimal clinical important difference/rehabilitation factors associated with mortise malalignment based on concomitant contact stress increase, which would warrant and identify which cases need surgical reduction.