Die Versorgung gelenknaher knöcherner Defekte mittels Megaendoprothesen stellt eine seltene, aber wichtige Behandlungsoption für die betroffenen Patienten dar. Durch eine Analyse der Standzeit und Komplikationen von proximalen und dista- len Femurteilersätzen war es Ziel dieser Arbeit die Ergebnisse der operativen Behandlung von Patienten mit Femurteilersätzen, welche vom 1. Juni 2009 bis 31. Dezember 2018 an der orthopädischen Universitätsklinik Würzburg behan- delt wurden, zu evaluieren und eine Grundlage für Handlungsempfehlungen für zukünftige Patienten und Studien zu ermöglichen. Eine signifikante postoperative Kompli kationsrate dieser aufwändigen Therapie- möglichkeit wurde in dieser Arbeit beobachtet. Infektionen stellten bei den dista- len Femurteilersätzen einen Hauptrevisionsgrund dar. Bei proximalen Femurtei- lersätzen führte vor allem das Auftreten von Luxationen zu notwendigen Revisi- onseingriffen. Trotz genauer präoperativer Vorbereitung sowie einer stabilen Ver- ankerung im Femur und adäquater Weichteilrekonstruktion, können diese Kom- plikationen auch in erfahrenen Händen nicht immer vermieden werden. Megaprothesen können aufgrund ihrer Modularität intraoperativ den entschei- denden Beitrag zum Extremitätenerhalt und Stabilität bieten. Die patientenindivi- duelle Situation muss im therapeutischen Vorgehen berücksichtigt werden und eine multidisziplinäre Nachbehandlung des Patienten ist für den weiteren Thera- pieerfolg ausschlaggebend. Der Erhalt der betroffenen Extremität wird häufig ermöglicht, eine Amputation war bei unseren Patienten nur viermal als Ultima Ratio notwendig geworden. Das teils junge und aktive Patientenklientel profitiert von einer langfristig guten Funktion. Weitere möglicherweise multizentrische prospektive Studien zur Verankerung und den Komplikationen der hier untersuchten Prothese vom Typ REVISIO®- RTM der Firma AQS sowie die Evaluation vergleichbarere modularer Prothesen- systeme erscheinen erstrebenswert. Durch den Vergleich der Standzeit der un- terschiedlichen Systeme und Verankerungsarten, könnte eine optimierte Prothe- sen-Verankerungskombination mit guten Ergebnissen identifiziert werden. / The use of mega-endoprostheses for addressing bony defects near joints is an uncommon but vital treatment option for affected patients. This study aimed to evaluate the outcomes of surgical interventions in patients who underwent proximal and distal femoral replacements at the Orthopaedic University Hospital Klinik König-Ludwig-Haus in Würzburg between June 1, 2009, and December 31, 2018. By examining the longevity and complications associated with these procedures, the goal was to establish a foundation for recommendations for future patients and research. A considerable postoperative complication rate was identified for this complex treatment method. In distal femoral replacements, infections were a leading cause of revision surgeries, while proximal femoral replacements were frequently affected by dislocations, necessitating further surgical intervention. Despite meticulous preoperative planning, secure fixation in the femur, and comprehensive soft tissue reconstruction, such complications cannot always be avoided, even by experienced surgeons. Megaprostheses, with their modular design, significantly contribute to limb preservation and surgical stability. Treatment approaches must consider the patient’s unique circumstances, and interdisciplinary postoperative care is crucial for achieving successful long-term outcomes. Limb preservation was often achievable, with amputation required in only four cases as a last resort. Many patients, including young and active individuals, experienced long-term functional benefits. Further research, such as multicenter prospective studies, is warranted to investigate the anchoring techniques and complication rates associated with the REVISIO®-RTM prosthesis from AQS and other comparable modular prosthetic systems.

Background: Modular mega-endoprosthesis systems are used to bridge very large bone defects and have become a widespread method in orthopaedic surgery for the treatment of tumours and revision arthroplasty. However, the indications for the use of modular mega-endoprostheses must be carefully considered. Implanting modular endoprostheses requires major, complication-prone surgery in which the limited salvage procedures should always be borne in mind. The management of periprosthetic infection is particularly difficult and beset with problems. Given this, the present study was designed to gauge the significance of periprosthetic infections in connection with modular mega-implants in the lower extremities among our own patients. Methods: Patients who had been fitted with modular endoprosthesis on a lower extremity at our department between September 1994 and December 2011 were examined retrospectively. A total of 101 patients with 114 modular prostheses were identified. Comprising 30 men (29.7 %) and 71 women (70.3 %), their average age at the time of surgery was 67 years (18–92 years). Results: The average follow-up period was 27 months (5 months and 2 weeks to 14 years and 11 months) and the drop-out rate was about 8.8 %. Altogether, there were 19 (17.7 %) endoprosthesis infections: 3 early infections and 16 late or delayed infections. The pathogen spectrum was dominated by coagulase-negative staphylococci (36 %) and Staphylococcus aureus (16 %), including 26 % multi-resistant pathogens. Reinfection occurred in 37 % of cases of infection. Tumours were followed by significantly fewer infections than the other indications. Infections were twice as likely to occur after previous surgery. Conclusion: In our findings modular endoprostheses (18 %) are much more susceptible to infection than primary endoprostheses (0.5–2,5 %). Infection is the most common complication alongside the dislocation of proximal femur endoprostheses. Consistent, radical surgery is essential – although even with an adequate treatment strategy, the recurrence rate is very high. Unfortunately, the functional results are frequently unsatisfactory, with amputation often being the last resort. Therefore, the indication for implantation must be carefully considered and discussed in great detail, especially in the case of multimorbid patients with previous joint infections.

Background: Modular mega-endoprosthesis systems are used to bridge very large bone defects and have become a widespread method in orthopaedic surgery for the treatment of tumours and revision arthroplasty. However, the indications for the use of modular mega-endoprostheses must be carefully considered. Implanting modular endoprostheses requires major, complication-prone surgery in which the limited salvage procedures should always be borne in mind. The management of periprosthetic infection is particularly difficult and beset with problems. Given this, the present study was designed to gauge the significance of periprosthetic infections in connection with modular mega-implants in the lower extremities among our own patients. Methods: Patients who had been fitted with modular endoprosthesis on a lower extremity at our department between September 1994 and December 2011 were examined retrospectively. A total of 101 patients with 114 modular prostheses were identified. Comprising 30 men (29.7 %) and 71 women (70.3 %), their average age at the time of surgery was 67 years (18–92 years). Results: The average follow-up period was 27 months (5 months and 2 weeks to 14 years and 11 months) and the drop-out rate was about 8.8 %. Altogether, there were 19 (17.7 %) endoprosthesis infections: 3 early infections and 16 late or delayed infections. The pathogen spectrum was dominated by coagulase-negative staphylococci (36 %) and Staphylococcus aureus (16 %), including 26 % multi-resistant pathogens. Reinfection occurred in 37 % of cases of infection. Tumours were followed by significantly fewer infections than the other indications. Infections were twice as likely to occur after previous surgery. Conclusion: In our findings modular endoprostheses (18 %) are much more susceptible to infection than primary endoprostheses (0.5–2,5 %). Infection is the most common complication alongside the dislocation of proximal femur endoprostheses. Consistent, radical surgery is essential – although even with an adequate treatment strategy, the recurrence rate is very high. Unfortunately, the functional results are frequently unsatisfactory, with amputation often being the last resort. Therefore, the indication for implantation must be carefully considered and discussed in great detail, especially in the case of multimorbid patients with previous joint infections.