Maximilian Johannes Hartel

Introduction: Fragility fractures of the pelvis (FFPs) are low-energy osteoporotic fractures that primarily affect elderly patients. They are associated with substantial morbidity, mortality and healthcare burden, and their incidence continues to rise as the global population ages. Despite the availability of dedicated classification systems and advances in surgical techniques, high-quality evidence to guide optimal management remains limited, and treatment algorithms are not standardised. To address these gaps, we established an international, observational cohort study designed to collect comprehensive data on patients with FFP and varying degrees of pelvic instability. The study aims to evaluate outcomes of non-operative and operative management and to identify predictors of favourable outcomes. Methods and analysis: This international, prospective, multicentre, observational cohort study will enrol approximately 420 patients aged ≥65 years with FFP (types II–IV) over a 4-year period at 10 large AO Trauma centres in the USA, Canada, Japan, Hong Kong, France, Switzerland, the Netherlands and Germany. Patients will be followed for up to 12 months. Data collected will include fracture characteristics, treatment details, radiological and functional outcomes, patient-reported outcomes, mortality and procedure-related adverse events. All treatments will adhere to the standard of care at each participating centre. Ethics and dissemination: Ethics approval was obtained from the responsible ethics committee at each participating site before recruitment. All patients will be enrolled following an informed consent process approved by the relevant ethics committee. Study results will be disseminated through peer-reviewed publications. Trial registration number: NCT04182776 .

Purpose: Tibial plateau fractures require precise preoperative planning, particularly regarding treatment concept, patient positioning, and surgical approach. Mixed reality (MR) may enhance three-dimensional understanding of fracture morphology beyond conventional imaging and physical 3D models. This study investigated whether MR improves agreement on key preoperative planning decisions compared to computed tomography (CT), 3D computed tomography (3DCT), and 3D-printed fracture models. Methods: Twelve orthopaedic trauma surgeons (6 junior, 6 senior) evaluated 22 surgically treated tibial plateau fractures (AO/OTA type B or C). Each case was assessed in four steps using (1) CT, (2) 3DCT reconstructions, (3) physical 3D-printed models, and (4) MR visualization using Microsoft Hololens 2. Raters selected (i) treatment concept, (ii) patient positioning, and (iii) surgical approach. Interobserver agreement was analysed using Fleiss’ kappa (κ) and percentage match (PM). Results: Mixed Reality (MR) yielded the highest interobserver agreement for both surgical approach (PM 32%, κ = 0.30) and patient positioning (PM 57%, κ = 0.35), particularly among junior surgeons (approach PM 39%, κ = 0.28; positioning PM 57%, κ = 0.39). Compared to CT, 3DCT, and 3D printing, MR demonstrated consistent improvements, while agreement on treatment concepts remained high across all modalities (PM > 82%). Conclusion: Mixed Reality (MR) improved interobserver agreement in preoperative planning for tibial plateau fractures, particularly for surgical approach selection and patient positioning. These effects were most pronounced among less experienced raters, highlighting MR’s role as a cognitive support tool and a promising instrument in surgical education. Compared to conventional imaging and 3D printing, MR provided dynamic interaction and greater planning flexibility. While further clinical validation is required, these findings support MR as a valuable adjunct in orthopaedic trauma planning. Level of evidence: Level II.

Purpose: Optimal anatomical reduction and stable fixation of acetabular fractures are important in avoiding secondary dislocation and osteoarthritis. Biomechanical studies of treatment options of acetabular fractures aim to evaluate the biomechanical properties of different fixation methods. As the setup of the biomechanical test can influence the experimental results, this review aimed to analyze the characteristics, comparability and clinical implications of studies on biomechanical test setups and finite element analyses in the fixation of acetabular fractures. Methods: A systematic literature research was conducted according to the PRISMA guidelines, using the PubMed/MEDLINE and Web of Science databases. 44 studies conducting biomechanical analyses of fixation of acetabular fractures were identified, which met the predefined inclusion and exclusion criteria and which were published in English between 2000 and April 16, 2021. The studies were analyzed with respect to distinct parameters, including fracture type, material of pelvis model, investigated fixation construct, loading direction, loading protocol, maximum loading force, outcome parameter and measurement method. Results: In summary, there was no standardized test setup within the studies on fixation constructs for acetabular fractures. It is therefore difficult to compare the studies directly, as they employ a variety of different test parameters. Furthermore, the clinical implications of the biomechanical studies should be scrutinized, since several test parameters were not based on observations of the human physiology. Conclusion: The limited comparability and restricted clinical implications should be kept in mind when interpreting the results of biomechanical studies and when designing test setups to evaluate fixation methods for acetabular fractures.

In this investigation, it was assumed that it must be possible to visualize the intrapelvic aspect as accustomed by pelvic surgeons using the anterior intrapelvic (modified Stoppa) approach. Moreover, it was hypothesized, that plate mountings will not only be possible for the symphysis but also at the supra- and infrapectineal aspect as well as to the posterior column. Ten anonymized cadaveric specimens were included in this study. A standard laparoscopic totally extraperitoneal (TEP) approach was used. A total of 10 landmarks were defined that are usually within reach in the open anterior intrapelvic (AIP) approach. Moreover, five different plate mountings were tested. The locations were chosen in accordance with the indication spectrum suitable for open surgery through the traditional AIP approach. It was possible to gain intrapelvic visibility in seven of ten cases. In all of those seven cases, it was technically possible to place plates to the symphysis, superior pubic ramus, as well as longer anterior column plates up to the aspect posterior of the acetabulum. In the last four of the seven cases, it was possible to mount plates to the infrapectineal aspect as well as the posterior column, too. The team, previously trained in arthroscopic surgical techniques as well as pelvic trauma surgery, observed a steep learning curve. This investigation demonstrated, that endoscopic anterior intrapelvic plate osteosynthesis was feasible in the majority of the cases in a series of ten cadaveric models. New instruments will be needed such as extra-long rasp elevators, ball-spikes as well as devices to hold and position plates and extra-long self-holding screwdrivers. With these, endoscopic pelvic surgery will likely be a realistic option for selected pelvic trauma cases in the future.

Purpose: To investigate the range of indications of an anatomical-preshaped three-dimensional suprapectineal plate and to assess the impact of the bone mass density on radiologic outcomes in different types of acetabular fractures. Patients and methods: A consecutive case series of 50 acetabular fractures (patient age 69 ± 23 years) treated with suprapectineal anatomic plates were analyzed in a retrospective study. The analysis included: Mechanism of injury, fracture pattern, surgical approach, need for additional total hip arthroplasty, intra- or postoperative complications, as well as bone mass density and radiological outcome on postoperative computed tomography. Results: Most frequently, anterior column fracture patterns with and without hemitransverse components as well as associated two column fractures were encountered. The anterior intrapelvic approach (AIP) was used in 98% (49/50) of the cases as primary approach with additional utilization of the first window of the ilioinguinal approach in 13/50 cases (26%). Determination of bone density revealed impaired bone quality in 70% (31/44). Postoperative steps and gaps were significantly greater in this subgroup (p < 0.05). Fracture reduction quality for postoperative steps revealed anatomic results in 92% if the bone quality was normal and in 46% if impaired (p < 0.05). In seven cases (14%), the plate was utilized in combination with acute primary arthroplasty. Conclusion: A preshaped suprapectineal plate provides good radiological outcomes in a variety of indications in a predominantly geriatric cohort. Impaired bone quality has a significantly higher risk of poor reduction results. In cases with extensive joint destruction, the combination with total hip arthroplasty was a valuable option.

Purpose: Anatomic reduction in tibial plateau fractures remains to be demanding. For further visualisation of and approach to the joint surface an extended lateral approach using a lateral femoral epicondyle osteotomy and subluxation of the lateral meniscus was recently described. First clinical and radiographic mid-term results of this technique are presented in this feasibility study. Method: Ten complex tibial plateau fractures treated with extended lateral approach and lateral meniscal subluxation were prospectively analysed. Clinical and radiographic results were objectified according to the Rasmussen scores. Results: After a median follow-up of 8.6 (IQR 4.3) months good to excellent clinical and radiographic results were noted. The clinical Rasmussen Score showed a median of 25 (IQR 2.8) and radiographic a median of 17 (IQR 2.0) points. Conclusion: Good to excellent clinical and radiological scores were obtained after using an extended lateral approach with lateral femoral epicondyle osteotomy and central meniscus subluxation. No approach specific complications could be observed.

Background A confident diagnosis and classification of proximal femoral and tibia fractures are crucial to determine further therapeutic procedures. Materials and methods In this article the current standards regarding diagnostic imaging of proximal femoral and tibia fractures are presented and the different classification systems are discussed. Conclusions Plain radiography in two planes remains the initial investigation of choice for suspected osseous injury. While this is usually sufficient to determine further procedures for injuries of the proximal femur, cross-sectional imaging is normally necessary in the diagnosis of proximal tibia fractures.

The goal of surgical reconstruction of comminuted tibial plateau fractures is an anatomical reconstruction and stable fixation of the articular surface. This can be difficult due to poor visualization of the posterolateral and central segments of the articular surface of the proximal tibia. To improve visualization, the lateral approach can be extended with an osteotomy of the femoral epicondyle. In most cases, use of the extended lateral approach allows the whole lateral plateau to be visualized. Nevertheless, in some cases, an osteotomy alone is not enough to expose the entire fracture, especially the central segments of the tibial plateau. For these specific cases, we developed an additional technical trick that significantly improves articular visualization; the lateral meniscocapsular fibers are dissected allowing for central subluxation of the lateral meniscus, while leaving the anterior and posterior roots intact. With central subluxation of the lateral meniscus in comminuted tibial plateau fractures, the joint surface can be completely visualized, allowing an anatomical reduction even in highly complex fractures. ^* Contributed equally.