Anastasios G Roustemis

Mr. Anastasios G Roustemis

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 August 2022 in Cancers
Verified
Journal Article
Open access
PDF file
Andreas G. TsantesAndreas G. Tsantes
Andreas G. Tsantes
ILIlectra Loukopoulou
Ilectra Loukopoulou
DPDimitrios V. Papadopoulos
Dimitrios V. Papadopoulos
ITIoannis Trikoupis
Ioannis Trikoupis
ARAnastasios G Roustemis
Anastasios G Roustemis
Argirios TsantesArgirios Tsantes
Argirios Tsantes
Introduction: A detailed evaluation of the malignancy-associated coagulopathy (MAC) in surgical patients with bone tumors may allow for more effective thromboprophylactic measures. The purpose of this study was to assess the perioperative hemostatic changes in patients with bone tumors, using rotational thromboelastometry (ROTEM). Methods: An observational study was performed, including 50 patients with bone tumors who underwent oncologic resection and 30 healthy controls, matched for age and gender. The preoperative and postoperative laboratory evaluation of coagulation in both groups included conventional coagulation tests and a ROTEM analysis. The results of the conventional coagulation tests and the ROTEM analysis were compared between the two groups. Results: The results of the conventional coagulation tests were comparable between the tumor patients and the healthy controls. However, compared to the healthy adults, the tumor patients had lower CT (p < 0.001) and CFT (p < 0.001) values suggesting a rapid induction of the coagulation cascade, elevated A10 (p < 0.001) and MCF (p < 0.001) values indicating a higher clot strength and platelet activation, and elevated LI60 (p < 0.001) values indicating hypofibrinolysis in patients with bone tumors. The multiple linear regression analysis (controlling for potential confounding factors) confirmed the independent association of bone tumors with these hemostatic changes. Conclusions: Our results support the advantageous use of a ROTEM in patients with bone tumors over conventional coagulation tests because the qualitative changes in the hemostatic profile of these patients that can be detected by a ROTEM analysis cannot be identified by conventional tests. The ROTEM results indicate that the hypercoagulable state in patients with bone tumors is caused by the malignancy-associated activation of the coagulation cascade, platelet activation, and hypofibrinolysis.

26 August 2025 in SICOT-J
Verified
Journal Article
Open access
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ARAnastasios G Roustemis
Anastasios G Roustemis
PGPanayiotis Gavriil
Panayiotis Gavriil
SGStavros Goumenos
Stavros Goumenos
ITIoannis Trikoupis
Ioannis Trikoupis
VKVasileios Karampikas
Vasileios Karampikas
PPPanayiotis J. Papagelopoulos
Panayiotis J. Papagelopoulos
Background: Proximal femoral megaprosthetic reconstruction is a well-established solution for extensive bone loss in the hip region. Despite its utility in limb salvage, it carries notable complication rates, reported between 30% and 40%, along with increased morbidity and mortality. This study evaluated implant and patient survival, failure modes, and associated risk factors. Methods: We retrospectively reviewed 165 patients who underwent proximal femoral megaprosthetic reconstruction between 2003 and 2023. Indications included primary bone tumors (n = 67), metastatic bone disease (n = 60), and non-oncologic conditions (n = 38). A total of 57 METS (Stanmore) and 108 MUTARS (Implantcast) implants were used. Median follow-up was 5 years (range: 0.25–17 years). Results: Mean implant survival was 5.13 years (range: 0.2–17 years), with an overall complication rate of 30.9%. The most common failure modes were type 1 (11.5%) and type 4 (13.3%) per Henderson classification. Five-year implant survival ranged from 60% to 70% across indications. Independent risk factors for type 4 failure included prolonged hospitalization (OR = 1.07, p = 0.020) and longer operative time (OR = 1.01, p = 0.023). Silver-coated implants showed a trend toward reduced infection (OR = 0.18, p = 0.29), though not statistically significant. METS implants were associated with lower type 1 failure risk (OR = 0.09, p = 0.020), with a soft-tissue failure rate of 3.5% versus 15.7% for MUTARS. Conclusion: Proximal femoral megaprostheses remain effective for limb salvage but are linked to a substantial complication burden. Recognition of modifiable and patient-specific risk factors may improve surgical outcomes and reduce failure rates.

11 March 2026 in Pathogens
Verified
Journal Article
Open access
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VKVasileios Karampikas
Vasileios Karampikas
SGStavros Goumenos
Stavros Goumenos
Andreas G. TsantesAndreas G. Tsantes
Andreas G. Tsantes
ITIoannis Trikoupis
Ioannis Trikoupis
PGPanayiotis Gavriil
Panayiotis Gavriil
PPPanayiotis J. Papagelopoulos
Panayiotis J. Papagelopoulos
Background: Periprosthetic joint infection (PJI) is a severe complication following megaprosthetic reconstruction in musculoskeletal oncology. This study aimed to evaluate outcomes of different surgical strategies for PJI in lower-limb megaprostheses and identify factors associated with treatment failure. Methods: We performed a retrospective cohort study of 29 consecutive patients treated for PJI after oncologic megaprosthetic reconstruction. Reinfection was analyzed using cumulative incidence functions (CIFs) with death treated as a competing event. Overall survival was assessed using Kaplan–Meier analysis. Univariable cause-specific Cox regression was performed for exploratory risk-factor analysis. Results: Among 29 patients, coagulase-negative staphylococci and Staphylococcus aureus were the most frequently isolated pathogens, and difficult-to-treat organisms were identified in a substantial proportion of cases. In patients managed with two-stage revision, the cumulative incidence of reinfection was 15% (95% CI: 0–30%) at 1 year and 30% (95% CI: 10–50%) at 2 and 5 years. In the DAIR cohort, the cumulative incidence of reinfection was 25% (95% CI: 0–62.5%) at 1 and 2 years and 37.5% (95% CI: 12.2–75%) at 3 years. Positive reimplantation cultures occurred in 38% of cases and were strongly associated with subsequent treatment failure. Polymicrobial infections were present in 27.5% of cases. Amputation was required in 17.2% of patients, often due to multidrug-resistant organisms or poor soft tissue. Conclusions: Two-stage revision remains the most effective strategy for PJI management in megaprostheses. DAIR may control acute infection but is suboptimal for definitive treatment. Individualized, multidisciplinary approaches are essential to improve outcomes in this high-risk population.

6 March 2025 in European Journal of Orthopaedic Surgery & Traumatology
Verified
Journal Article
Closed access
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KAKonstantinos Avgerinos
Konstantinos Avgerinos
SKSpyridon Katsanos
Spyridon Katsanos
PAPavlos Altsitzioglou
Pavlos Altsitzioglou
AZAlexandros Zikopoulos
Alexandros Zikopoulos
ARAnastasios G Roustemis
Anastasios G Roustemis
Andreas F. MavrogenisAndreas F. Mavrogenis
Andreas F. Mavrogenis

30 October 2025 in Cureus
Verified
Journal Article
Open access
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ARAnastasios G Roustemis
Anastasios G Roustemis
DKDimitrios Koulalis
Dimitrios Koulalis
DMDimitrios S. Mastrokalos
Dimitrios S. Mastrokalos
Background Precise femoral tunnel placement is a critical determinant of anterior cruciate ligament (ACL) reconstruction success. This study aimed to evaluate the accuracy of transtibial aiming in relation to a predrilled anatomic femoral tunnel using radiographic and intraoperative photographic measurements. Methodology In total, 43 single-bundle ACL reconstructions with hamstring autografts were analyzed. After drilling the femoral tunnel through the anteromedial portal, a 4-mm offset guide was inserted transtibially toward its center. Tibial tunnel angles were measured in coronal and sagittal planes, and the absolute distance (D) between the centers of the femoral tunnel and the transtibial K-wire was recorded. A normalized index (I = D/radius, R) was calculated, with I <1 indicating that the transtibial wire remained within the tunnel perimeter. Results The mean femoral tunnel diameter was 7.44 mm (R = 3.72 mm), mean D was 4.50 mm (1.75-6.85 mm), and the overall mean index was 1.2. For tunnels of 7.0 and 7.5 mm, the mean index exceeded 1, while for tunnels of 8.0-9.0 mm, it was less than 1. Deviation showed no correlation with tibial tunnel angulation. In no case did the transtibial K-wire reach the exact femoral center. Conclusions The findings of this study demonstrated that transtibial aiming lacks sufficient precision for anatomic femoral tunnel placement, supporting the anteromedial portal approach as the more accurate technique.

22 August 2024 in Microorganisms
Verified
Journal Article
Open access
PDF file
Andreas G. TsantesAndreas G. Tsantes
Andreas G. Tsantes
ADAglaia Domouchtsidou
Aglaia Domouchtsidou
KTKonstantina A. Tsante
Konstantina A. Tsante
PIPetros Ioannou
Petros Ioannou
AMAlexandra Mpakosi
Alexandra Mpakosi
DPDimitrios V. Papadopoulos
Dimitrios V. Papadopoulos
Background: Periprosthetic joint infections (PJIs) are associated with altered coagulation dynamics; therefore, coagulation laboratory studies could be valuable for diagnosing PJI. This study aimed to evaluate the diagnostic role of Rotational Thromboelastometry (ROTEM) in detecting PJIs caused by low-virulence pathogens. Methods: A retrospective study was conducted, enrolling 78 patients who underwent exchange arthroplasty due to PJI due to high-virulence pathogens (Group A, n = 16), low-virulence pathogens (Group B, n = 20), or due to aseptic loosening (Group C, n = 20). Preoperative laboratory findings were compared among the three groups. Results: Several ROTEM parameters differed in patients with PJIs caused by low-virulence pathogens, indicating a link between these infections and hypercoagulability. The development of low-virulence PJIs was associated with a higher maximum clot firmness (MCF) (Odds Ratio, 1.12; 95% Confidence Interval, 1.04–1.21; p = 0.001). Additionally, EXTEM MCF was found to have the highest diagnostic accuracy for these infections (Area Under the Curve, 0.841; sensitivity 90.0%; specificity 90.4%), surpassing that of C-reactive protein and the Erythrocyte Sedimentation Rate (p = 0.006 and p = 0.019, respectively). Conclusions: Our findings suggest that ROTEM analysis is a promising method for detecting the altered hemostatic dynamics associated with PJI caused by low-virulence pathogens.