Projects Hirtler Lab
Stability after Intramedullary nail removal
As the incidence of osteoporosis is rising, trochanteric fractures are one of the most common and disabling fractures in elderly people, especially affecting postmenopausal women. Treatment of choice for pertrochanteric fracture are osteosynthesis devices, such as the gamma nail or proximal femur nail. However, optimal management and the respective complication for each device are still controversial. One of the least investigated topics regarding postoperative care is the need of implant removal after healing. Extraction of intramedullary nails are not routine, however, due to pain, often necessary. As intramedullary implants alter the force transmission and leave a big cavity in the femoral bone, removal can lead to fatigue fractures, resulting in longer hospital stays and rehabilitation period. The aim of this study is to evaluate the initial stability after removal of in-vivo implanted intramedullary gamma and proximal femur nails compared to the normal contralateral side. (Funded by the Medical Scientific Fund of the Major of Vienna)
Three-Dimensional Osseointegration Patterns of Cementless Press-Fit Acetabular Cups
Aseptic loosening of the acetabular component remains one of the leading causes of revision surgery after total hip arthroplasty. Cementless press-fit acetabular cups rely on primary stability and subsequent biological osseointegration, yet it remains unclear to what extent different regions of the cup contribute to long-term fixation and how accurately radiographs reflect true osseointegration. A combined radiological and histological assessment may provide valuable insight into implant anchorage and bone integration. We aim at evaluating the osseointegration of cementless press-fit acetabular cups by correlating standardized radiographic findings with histological thin-section analysis across defined acetabular zones.
Morphometry of the superior alveolar nerve and its sensory branches
The superior alveolar nerve and the superior dental plexus arising from it are important central structures of the tooth-bearing jaw. After the loss of teeth, these structures can demonstrably lose substance. The question arises as to what extent the dentition has an influence on this loss of substance. We therefor aim to investigate the influence of tooth loss on the diameter and number of nerve fibers in dentulous, partially dentulous, edentulous and implanted jaws. (Funded by the Medical Scientific Fund of the Major of Vienna)
Plexus architecture
The human body contains four major somatic nerve plexuses – the cervical, brachial, lumbar and sacral – which consist predominantly of sensory and motor axons with contributions from autonomic fibers . Successful nerve repair depends, in part, on appropriate matching between donor and defective nerve, including similarities in fascicle size and number . Studies have demonstrated that using mixed (sensory and motor) donor nerves to repair mixed nerve defects yield superior outcomes compared to the use of solely sensory donor nerves . Therefore, detailed knowledge of fascicular and axonal composition of nerve plexuses is critical for optimizing surgical repair strategies. Our aim is to investigate plexus morphometry, including fascicular organization and axonal architecture with a special focus on the distribution of autonomous nerves.