Refine
Has Fulltext
- yes (3)
Is part of the Bibliography
- yes (3)
Document Type
- Journal article (3) (remove)
Keywords
- fixation (3) (remove)
Institute
- Klinik und Poliklinik für Unfall-, Hand-, Plastische und Wiederherstellungschirurgie (Chirurgische Klinik II) (2)
- Abteilung für Funktionswerkstoffe der Medizin und der Zahnheilkunde (1)
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen (1)
- Lehrstuhl für Orthopädie (1)
- Lehrstuhl für Tissue Engineering und Regenerative Medizin (1)
- Pathologisches Institut (1)
Background
The role of cement-augmented screw fixation for calcaneal fracture treatment remains unclear. Therefore, this study was performed to biomechanically analyze screw osteosynthesis by reinforcement with either a calcium phosphate (CP)-based or polymethylmethacrylate (PMMA)-based injectable bone cement.
Methods
A calcaneal fracture (Sanders type IIA) including a central cancellous bone defect was generated in 27 synthetic bones, and the specimens were assigned to 3 groups. The first group was fixed with four screws (3.5 mm and 6.5 mm), the second group with screws and CP-based cement (Graftys (R) QuickSet; Graftys, Aix-en-Provence, France), and the third group with screws and PMMA-based cement (Traumacem (TM) V+; DePuy Synthes, Warsaw, IN, USA). Biomechanical testing was conducted to analyze peak-to-peak displacement, total displacement, and stiffness in following a standardized protocol.
Results
The peak-to-peak displacement under a 200-N load was not significantly different among the groups; however, peak-to-peak displacement under a 600- and 1000-N load as well as total displacement exhibited better stability in PMMA-augmented screw osteosynthesis compared to screw fixation without augmentation. The stiffness of the construct was increased by both CP- and PMMA-based cements.
Conclusion
Addition of an injectable bone cement to screw osteosynthesis is able to increase fixation strength in a biomechanical calcaneal fracture model with synthetic bones. In such cases, PMMA-based cements are more effective than CP-based cements because of their inherently higher compressive strength. However, whether this high strength is required in the clinical setting for early weight-bearing remains controversial, and the non-degradable properties of PMMA might cause difficulties during subsequent interventions in younger patients.
Hintergrund
Die Symphysensprengung mit entsprechender Diastase kann durch eine Symphysenplatte stabilisiert werden.
Fragestellung
Welche Beckenverletzungen werden mit einer Symphysenplatte stabilisiert und wie ist das Outcome?
Material und Methoden
Retrospektive Auswertung von 64 Patienten über einen Untersuchungszeitraum von 24 Monaten.
Ergebnisse
Es waren 56 Patienten männlich, 8 weiblich und das mittlere Alter betrug 44 Jahre (SD ± 17). Unfälle im Straßenverkehr waren der führende Grund für die Beckenverletzung. Die Verteilung nach AO-Klassifikation zeigte sich wie folgt: 14-mal B1-, 10-mal B2-, 5‑mal B3-, 23-mal C1-, 9‑mal C2- und 3‑mal C3-Verletzungen. Die Verteilung nach Young und Burgess ergab: 9‑mal APC-I-, 18-mal APC-II-, 13-mal APC-III-, 9‑mal LC-I-, 3‑mal LC-II-, 2‑mal LC-III- und 10-mal VS-Verletzungen. Der mittlere Injury Severity Score (ISS) betrug 32 und die mittlere stationäre Verweildauer 29 Tage (pos. Korrelation p ≤ 0,001). Im Verlauf war eine radiologische Implantatlockerung bei 52 Patienten nachweisbar. Therapierelevante Komplikationen gab es in 14 Fällen. Hierbei war das Implantatversagen (n = 8) der Hauptgrund für eine operative Revision.
Diskussion
Obwohl die radiologische Implantatlockerung häufig beobachtet wird, ist sie nur selten Grund für einen Revisionseingriff. Kommt es hingegen zum vollständigen Implantatversagen, tritt dies meist innerhalb der ersten postoperativen Wochen auf und ist revisionsbedürftig. Eine frühzeitige Abklärung durch Röntgenbildgebung sollte bei Verdacht erfolgen.
Due to the wide variety of benign and malignant salivary gland tumors, classification and malignant behavior determination based on histomorphological criteria can be difficult and sometimes impossible. Spectroscopical procedures can acquire molecular biological information without destroying the tissue within the measurement processes. Since several tissue preparation procedures exist, our study investigated the impact of these preparations on the chemical composition of healthy and tumorous salivary gland tissue by Fourier-transform infrared (FTIR) microspectroscopy. Sequential tissue cross-sections were prepared from native, formalin-fixed and formalin-fixed paraffin-embedded (FFPE) tissue and analyzed. The FFPE cross-sections were dewaxed and remeasured. By using principal component analysis (PCA) combined with a discriminant analysis (DA), robust models for the distinction of sample preparations were built individually for each parotid tissue type. As a result, the PCA-DA model evaluation showed a high similarity between native and formalin-fixed tissues based on their chemical composition. Thus, formalin-fixed tissues are highly representative of the native samples and facilitate a transfer from scientific laboratory analysis into the clinical routine due to their robust nature. Furthermore, the dewaxing of the cross-sections entails the loss of molecular information. Our study successfully demonstrated how FTIR microspectroscopy can be used as a powerful tool within existing clinical workflows.