Research grants

Investigators: Boglarka Gabriella Barsony / Sebastian Knell / Brian Park / AC-00798 Federico Longo, University of Zürich (Vetsuisse faculty)

Sacroiliac luxation (SIL) is a common condition in cats undergoing blunt trauma. Between 59–93% of feline patients with pelvic fractures have SIL, with 27–46% being bilateral.

Beyond pain and lameness, SIL can lead to pelvic canal narrowing and disruption of the neurologic supply to the pelvic limbs. Surgical stabilization reduces discomfort, accelerates recovery, and helps establish pelvic canal morphology. While various fixation techniques are proposed, no biomechanical studies have definitively identified the optimal method for stabilizing SIL in cats.

We hypothesize that: Stabilization techniques provide stability comparable to that of the native state.

Restoring stability in a bilateral SIL is inherently more challenging compared to a unilateral SIL injury, regardless of the stabilization technique employed. Bilateral lag screw fixation offers the greatest strength in bilateral SIL between bilateral stabilization techniques.

This study evaluates the biomechanical behavior of four different surgical fixation techniques for feline SIL. Fifty sacroiliac joint specimens will be divided into five groups:
1) native joint,
2) unilateral defect with lag screw fixation,
3) bilateral defect stabilized with bilateral lag screws,
4) bilateral defects stabilized with Amex ilial bolts and nuts, and
5) bilateral defect stabilized with toggle pins.

Post-fixation CT imaging will confirm successful implant positioning. The specimen will be tested using a servo-hydraulic mechanical testing machine. An initial cyclic axial compression test followed by load-to-failure testing will be performed.

The test will evaluate stiffness, maximum load at failure, and failure modes. The parameters will be compared between each other and to the native joint using inferential statistics.

By identifying the optimal fixation method, this project seeks to improve clinical outcomes, enhance patient recovery, and contribute to the body of knowledge guiding feline orthopedic surgery.

Investigators: David Benedikt Osche / Tobias Fritz / Marcel Orth / Antonius Pizanis / Emmanouil Liodakis, Klinik für Unfall-, Hand- und Wiederherstellungschirurgie, Universitätsklinikum des Saarlandes

Pelvic ring fractures are the third most common injuries in geriatric patients. A distinction is generally made between traumatic pelvic ring fractures, which are categorized according to the AO/Tile classification, and fragility fractures (FFP), categorized according to the classification of the same name, differentiating these injuries from high-energy trauma.

For pelvic ring injuries, a staged diagnostic approach is used, with radiographic studies providing reliable results in detecting anterior pelvic ring fractures. However, posterior ring injuries are rarely radiographically detectable, which is why a CT scan should be performed when anterior ring disruption is confirmed.

Patients are then admitted for analgesia and mobilization (non-operative) or for surgical treatment. If the primary treatment fails (immobility despite adequate analgesia), surgical stabilization is required. To date, there is no evidence-based recommendation in the literature as to which FFP should be treated, which often leads to a delay.

The aim of this study is to evaluate the possibility of early treatment decisions for FFP. 2 low-dose CT (neutral position and figure of 4) are performed at the time of diagnosis of a FFP. Using special software (Computer Tomography Migration Analysis, SECTRA, Sweden), the fracture translation can be measured. The software is already being used diagnosing implant loosening after total hip and knee arthroplasty, replacing the complex technique of radiostereometry. Both the potential measurability of the parameters and the simultaneous dose reduction compared to conventional CT have been demonstrated.

The modified diagnostics have no effect on the treatment of the patients, which is carried out according to the hospital treatment protocol. The evaluation of whether the fracture translation measured in the primary CT has an effect on fracture stability and thus on treatment is evaluated retrospectively.

Investigators: Jan Gewiess / Christoph Albers, Inselspital, Bern University Hospital, University of Bern

Type 2 odontoid fractures of the second cervical vertebra (C2) are common in geriatric patients and require accurate stability assessments to guide treatment. Current practice relies on static imaging methods, such as CT and radiographs, which may not fully capture the dynamic behavior of the cervical spine, potentially leading to misclassification of fracture stability.

We hypothesize that dynamic biplanar radiographic imaging will provide a more accurate assessment of fracture displacement and atlantoaxial stability in geriatric patients with type 2 odontoid fractures compared to standard static imaging techniques.

This prospective observational pilot study aims to evaluate the feasibility of dynamic biplanar radiographic imaging in assessing fracture stability among geriatric patients treated nonoperatively. We plan to enroll 24 patients over 18 months, targeting Caucasian individuals aged 60 years and older treated at a Level I trauma center. Based on clinical experience, we anticipate 16 patients with <4 mm fracture displacement and 8 patients with ≥4 mm displacement. All participants will undergo high-resolution CT and upright radiographs at initial presentation, followed by cervical collar immobilization for 6 to 12 weeks. At the 12-week follow-up, patients will undergo dynamic biplanar radiographic imaging to assess cervical spine movement in flexion, extension, and rotation.

Primary outcomes will include measurements of fracture displacement, angulation, and atlantoaxial instability from dynamic imaging, alongside clinical outcomes such as pain and functional scores. The results from dynamic imaging will be compared to standard static imaging and data from healthy controls.

This pilot study will generate preliminary data necessary for determining the sample size for a future randomized controlled trial comparing clinical outcomes and imaging-based assessments between nonoperatively and operatively treated patients with type 2 odontoid fractures.

Investigators: Roman Taday / Max Prost, University Hospital Düsseldorf

The aging population has led to an increased incidence of fragility fractures of the pelvis (FFP), typically resulting from low-energy trauma such as falls from standing height. Unlike high-energy pelvic fractures, FFP are characterized by fractures of osteoporotic bone with intact ligamentous structures, often resulting in minimally displaced pelvic rings. However, the relative instability and poor bone quality in these patients can lead to fracture progression or insufficiency fractures of the remaining pelvic ring.

Current guidelines advocate for conservative management of FFP Type I and surgical intervention for FFP Types III and IV. However, no consensus exists regarding the optimal treatment for FFP Type II. Early mobilization is the primary therapeutic goal for these patients, as immobility exacerbates morbidity and mortality in this frail population. Biomechanical studies proved that stabilizing the anterior fracture component significantly improves overall pelvic ring stability. While minimally invasive screw fixation of the posterior and anterior pelvic rings under 3D navigation is well-established, the impact of additional anterior stabilization on mobility and morbidity outcomes remains unclear.

This prospective, randomized, controlled single center study aims to evaluate whether supplemental transpubic screw fixation in FFP II- III improves patient outcomes. Eligible geriatric patients with FFP II- III will be randomized either for illiosacral screw fixation only or additional transpubic screw fixation under 3D navigation. Patient outcomes assessed in terms of mobility (DEMMI- Score), morbidity, and quality of life over time (In-patient, 6 weeks, 6 months- follow up).

This research addresses a critical gap in the management of geriatric patients with FFP, aiming to establish evidence-based guidelines for optimal treatment strategies.

Investigators: Filippo Vandenbulcke / Lorenzo Di Mento, IRCCS Humanitas Research Hospital

Background:
Microbial colonization of osteosynthesis materials is often observed, even in patients without clinical signs of infection. This phenomenon raises questions about the relationship between colonization and infection, particularly osteomyelitis. 

Aim:
This study investigates the microbial colonization of osteosynthesis material and evaluates histological signs of osteomyelitis in surrounding bone tissue. Our hypothesis is that microbial colonization does not necessarily lead to infection. 

Methods:
Using a prospective cohort design, we will analyze microbial samples from osteosynthesis material and surrounding bone tissue in patients undergoing hardware removal. Histological and microbiological assessments will determine colonization patterns and the presence of osteomyelitis. 

Relevance:
Considerable research efforts are underway to develop increasingly sensitive tools for identifying bacteria, but the question remains whether their presence is truly pathogenic. Understanding the distinction between colonization and infection is critical for optimizing clinical management, potentially reducing unnecessary interventions and antibiotic use. 

PICOT Framework:
P: Patients undergoing removal of osteosynthesis material without clinical or laboratory signs of infection.
I: After hardware sonication, the sonication fluid wiil be cultivated in blood culture bottles and PCR analysis will be perfomed.
C: Surrounding bone samples will be collected for histologic examination.
O: Comparison of the histological infection rate with the colonization rate.
T: Two-year study duration. 

Expected Results:
We expect microbial colonization will not correlate with histological infection. This data will elucidate the clinical significance of microbial colonization. 

Long-term Goal:
To refine diagnostic criteria for infection associated with osteosynthesis materials, minimizing overtreatment and promoting antibiotic stewardship.

Investigators: Alessandra Berton / Rocco Papalia / Giuseppe Pascarella / Giacomo Rizzello / Eleonora Di Pinto, Fondazione Policlinico Campus BioMedico

Background:
Hip fractures in the elderly cause high morbidity and mortality. Surgery within 48 hours is vital to reduce complications. However, patients on anticoagulant or antiplatelet therapy often face delayed surgeries due to bleeding risks and contraindications to spinal or neuraxial anesthesia, increasing the likelihood of perioperative complications. Ultrasound-guided local infiltration analgesia (US-LIA) is a precise and safe technique, with promising potential for intraoperative use in patients on antithrombotic therapy.

Aim:
Evaluate US-LIA with vasoconstrictors as a novel anesthesia, ensuring effective pain control and minimizing bleeding risk in hip fracture patients on antithrombotic therapy .

Relevance:
By facilitating timely surgeries within the critical 48-hour window, US-LIA can significantly reduce perioperative complications and improve patient outcomes.

Materials and Methods:
This prospective, randomized, controlled trial will include 50 patients aged 65 years or older with hip fractures requiring hemiarthroplasty and on antithrombotic therapy. Participants will be randomized into 2 groups: one receiving US-LIA with vasoconstrictors and the other undergoing traditional regional anesthesia. The US-LIA procedure involves 3 steps: anterior pericapsular, posterior pericapsular, and subcutaneous LIA.
Primary outcomes include time to surgery, perioperative complications, 1 month and 1 year mortality.
Secondary outcomes focus on need for conversion to general anesthesia, time to the first rescue analgesic request, intraoperative surgical bleeding volume, adverse events.

Expected Results:
The US-LIA group will achieve lower time to surgery, less perioperative complications, and reduced mortality. Prolonged pain relief, reduced bleeding and low incidence of adverse events are also expected.

Long-Term Goal:
The goal is to establish US-LIA as an anesthetic option for antithrombotic patients, enabling timely surgery, reducing complications, and improving outcomes.

Investigators: Lefteris Manouras / Vassiliki Mitsi / Theodoros Tosounidis, University Hospital of Heraklion

Osteosarcopenia, osteoporosis/ osteopenia and sarcopenia both present within the same individual, is a major geriatric syndrome recently described. The presence of this syndrome is increasing due to the accelerated aging population and has been correlated among others with high rates of fragility fractures, especially hip fractures, and high rates of mortality. Therefore, further research on osteosarcopenia pathogenesis, epidemiology and treatment becomes increasingly relevant.

Our team aims to get an insight into molecular basis of osteosarcopenia by analyzing gene expression profile in muscle and adipose tissue from osteosarcopenic patients with hip fracture. In particular, during hip fracture surgery, muscle and adipose tissue and blood serum will be collected from three different patient groups:
a) patients with osteosarcopenia
b) patients with osteoporosis and
c) control group patients (no fracture/ osteoporosis/ osteosarcopenia).

Muscle and adipose tissue will be processed and submitted accordingly for RNA-sequencing analysis. Bioinformatic tools will be used to identify gene expression signatures, genes and molecular pathways with a pivotal role in the pathophysiology of osteosarcopenia and osteoporosis. The desired goal is to elucidate the largely unexplored molecular basis of osteoporosis and osteosarcopenia and propose potential therapeutic targets for the aforementioned conditions.

Results will also be analyzed along with patient corresponding findings from musculoskeletal ultrasound imaging, DEXA measurements and grip strength to identify any significant correlations. Finally, blood serum will be used to screen for potential biomarkers for diagnosis of osteosarcopenia. By combining molecular with clinical findings, the current proposal is designed to expand research on musculoskeletal system with the ultimate aim to prevent and treat effectively hip fractures in elderlies with osteosarcopenia.