Focal Therapy for Renal Cancer: Comparative Trends in the USA and Germany from 2006 to 2020 and Analysis of the German Health Care Landscape.

INTRODUCTION: The aim of the study was to investigate trends of FT for in-patient treatment of renal RCC in the USA and Germany. METHODS: We analyzed the SEER database for the USA and the nationwide German hospital billing database each from 2006 to 2019 for a RCC diagnosis in combination with FT, radical nephrectomy, and partial nephrectomy. FT was defined as radiofrequency ablation (RFA) or cryotherapy. Linear regression analysis was performed to detect changes over time. RESULTS: For the USA, we included 7,318 FT cases. The share of FT increased from 2.4% in 2006 to 6.4% in 2019 (p < 0.001). For Germany, we identified 2,920 FT cases. The share of FT increased from 0.7% in 2006 to 2.0% in 2019 (p < 0.001). The number of RFAs in the USA steadily increased by 227% from a total of 93 in 2006 to 304 in 2019 while the number of cryotherapies in the USA steadily increased by 289% from a total of 127 in 2006 to 494 in 2019 (p < 0.001). The number of RFAs in Germany increased by 344% from a total of 59 in 2006 to 262 in 2019 (p < 0.001) while the number of cryotherapies steadily increased by 43% from a total of 54 in 2006 to 77 in 2019 (p < 0.001). In Germany, RFA is significantly more performed than cryotherapy while in the USA cryotherapy is more frequently applied. CONCLUSION: We observed a constant increase of FT in the USA and Germany for RCC in-patient treatment with a higher share in the USA.

Vascularization of Primary, Peripheral Lung Carcinoma in CEUS - A Retrospective Study (n = 89 Patients).

PURPOSE: To describe the vascularization of peripheral lung carcinoma in CEUS and to compare with B-mode ultrasound (US) and clinical data. MATERIALS AND METHODS: From April 2004 until September 2015, n = 89 patients with peripheral lung carcinoma were investigated by B-mode US and CEUS. The extent (EE: hypoechoic, hyperechoic), homogeneity (HE: homogeneous, inhomogeneous) and time of enhancement (TE) have been defined. Early pulmonary-arterial enhancement (PA) before contrast floating to the thoracic wall was differentiated from simultaneous or delayed bronchial-arterial enhancement (BA). CEUS parameters were compared by B-mode US and histology. RESULTS: n = 25 patients had early PA enhancement (TE: 8 ±â€Š3.7 s), and n = 64 (72 %) had simultaneous/delayed BA enhancement (TE: 17.6 ±â€Š6.2 s) (p < 0.001). PA enhancement (EE/HE) was hyperechoic (n = 11/25), homogeneous (n = 11/25) and showed an air bronchogram more often (n = 11/17, p < 0.001). BA enhancement (EE/HE) was frequently hypoechoic (n = 34/64) and inhomogeneous (n = 54/64). BA enhancement was associated with necrosis (n = 36/42, p = 0.009). PA and BA enhancement distributed to different histologies: n = 42 adenocarcinomas (18 PA, 24 BA), n = 30 squamous cell carcinomas (4 PA, 26 BA), n = 13 other types of NSCLC (3 PA, 10 BA), and n = 4 SCLC (0 PA, 4 BA) (p = 0.016). CONCLUSION: The vascularization of peripheral lung carcinomas is heterogeneous and is influenced by histology. In this study, lung carcinomas are predominantly supplied by bronchial arteries, whereas a part of adenocarcinomas and non-adenocarcinomas show PA enhancement.

Midterm follow-up after implantation of a polyurethane meniscal scaffold for segmental medial meniscus loss: maintenance of good clinical and MRI outcome.

PURPOSE: The preservation of meniscal structure and function after segmental meniscal loss is of crucial importance to prevent early development of osteoarthritis. Implantation of artificial meniscal implants has been reported as a feasible treatment option. The purpose of this study was to assess the clinical and magnetic resonance imaging (MRI) results 4 years after implantation of a polyurethane scaffold for chronic segmental medial meniscus deficiency following partial medial meniscectomy. METHODS: Eighteen patients received arthroscopic implantation of an Actifit(®) polyurethane meniscal implant (Orteq Sports Medicine, London, UK) for deficiency of the medial meniscus. Patients were followed at 6, 12, 24, and 48 months. Clinical outcome was assessed using established patient-reported outcome scores (KOOS, KSS, UCLA Activity Scale, VAS for pain). Radiological outcome was quantified by MRI scans after 6, 12, 24, and 48 months evaluating scaffold morphology, tissue integration, and status of the articular cartilage as well as signs of inflammation. RESULTS: Median patient age was 32.5 years (range 17-49 years) with a median meniscal defect size of 44.5 mm (range 35-62 mm). Continuing improvement of the VAS and KSS Knee and Function Scores could be observed after 48 months compared to baseline, whereas improvement of the activity level according to UCLA continued only up to 24 months and decreased from there on. The KOOS Score showed significant improvement in all dimensions. MRI scans showed reappearance of bone bruises in two patients with scaffold extrusion. No significant changes in the articular cartilage could be perceived. CONCLUSION: Arthroscopic treatment for patients with chronic segmental meniscal loss using a polyurethane meniscal implant can achieve sustainable midterm results regarding pain reduction and knee function. LEVEL OF EVIDENCE: IV.

Initial stability of a new cementless fixation method of a tibial component with polyaxial locking screws: a biomechanical in vitro examination.

INTRODUCTION: Cementless fixation of the tibial component is critical as reduced initial stability leads to implant failure. In this experimental in vitro study, a new fixation method of the tibial component using polyaxial locking screws is evaluated using Roentgen stereophotogrammetric analysis (RSA). MATERIALS AND METHODS: A special prototype of a tibial component with four polyaxial locking screws was tested on 10 fresh-frozen human tibia specimens. The components were tested with an axial load of 2000 N for 10,000 cycles. Radiographs in two views were performed before loading, after 1000 and after 10,000 cycles, respectively. Besides rotation and translation along the x-, y-, and z-axes, endpoints for RSA were maximum subsidence (MaxSub), maximum lift off (MaxLiftOff) and maximum total point motion (MTPM). RESULTS: MaxSub increased from -0.5 mm (SD = 0.2) after 1000 cycles to -0.9 mm (SD = 1.1). MaxLiftOff was 0.1 mm after 1000 cycles and did not increase after 10,000 cycles. The MTPM was 0.7 mm (SD = 0.3) after 1000 cycles and 1.1 mm (SD = 1.1) after 10,000 cycles. Two out of nine implants showed an MTPM ≥ 1.0 mm after 10,000 cycles. CONCLUSIONS: Polyaxial locking screws can potentially improve the initial stability of tibial components. The results of this study indicate that the use of such screws in total knee arthroplasty may be of interest in the future. Further experimental and clinical investigation is needed.

Magnetic resonance-imaging of the effect of targeted antiangiogenic gene delivery in a melanoma tumour model.

OBJECTIVES: We investigated the effect of targeted gene therapy to melanoma tumours (M21) by MR-imaging. METHODS: M21 and M21-L tumours were grown to a size of 850 mm(3). M21 and M21-L tumours were intravenously treated with an αvß3-integrin-ligand-coupled nanoparticle (RGDNP)/RAF(-) complex five times every 72 hours. MRI was performed at set time intervals 24h and 72h after the i.v. injection of the complex. The MRI protocol was T1-wt-SE±CM, T2-wt-FSE, DCE-MRI, Diffusion-wt-STEAM-sequence, T2-time obtained on a 1.5-T-GE-MRI device. RESULTS: The size of the treated M21 tumours kept nearly constant during the treatment phase (847.8±31.4 mm(3) versus 904.8±44.4 mm(3)). The SNR value (T2-weighted images) of the tumours was 36.7±0.6 and dropped down to 30.6±1.9 (p=0.004). At the beginning the SNR value (T1-weighted images) of the tumours after contrast medium application was 42.3±1.9 and dropped down to 28.5±3.0 (p<0.001). In the treatment group the diffusion coefficient increased significantly under therapy (0.54±0.01x10(-3) mm(2)/s versus 0.67±0.04x10(-3) mm(2)/s). The DCE-MRI showed a reduction of the slope and of the Akep of 67.8±4.3 % respectively 64.8±3.3 % compared to baseline. CONCLUSIONS: Targeted gene delivery therapy induces significant changes in MR-imaging. MRI showed a significant reduction of contrast medium uptake parameters and increase of the diffusion coefficient of the tumours. KEY POINT: • Treatment with targeted gene-delivery therapy can be monitored by MR imaging • DCE and diffusion-weighted imaging are appropriate methods for monitoring this therapy • Functional changes are significant prior to any morphological changes.

Short-term follow up after implantation of a cell-free collagen type I matrix for the treatment of large cartilage defects of the knee.

PURPOSE: Although there are various new scaffold-based techniques for cartilage regeneration it remains unclear up to which defect size they can be used. The present study reports of a cell-free collagen type I gel matrix for the treatment of large cartilage defects of the knee after a two-year follow-up. METHODS: Twenty-eight patients with a mean cartilage defect size of 3.71 ± 1.93 cm² were treated with a cell-free collagen type I gel matrix (CaReS-1S®, Arthro Kinetics AG, Krems/Donau, Austria) via a mini-arthrotomy. Clinical outcome was assessed preoperatively and six weeks as well as six, 12 and 24 months after surgery using various clinical outcome scores (IKDC, Tegner, KOOS, VAS). Cartilage regeneration was evaluated via MRI using the MOCART score. RESULTS: Seventeen male and 11 female patients with a mean age of 34.6 years were included in this study. Significant pain reduction (VAS) could be noted after six weeks already. Patient activity (IKDC, Tegner) could be significantly improved from 12 months on and nearly reached reported pre-operative values. All subject categories of the KOOS except for symptom (swelling) showed significant improvements throughout the study. Constant significant improvements of the mean MOCART score were observed from 12 months on. MR images did not yield any signs of infection or synovitis. After 24 months a complete defect filling could be noted in 24 out of 28 cases with a mainly smooth surface, complete integration of the border zone and homogenous structure of the repaired tissue. CONCLUSION: Cell-free collagen type I matrices appear to be a safe and suitable treatment option even for large cartilage defects of the knee. Results of this study were comparable to the better-established findings for small cartilage defects. Mid- and long-term results will be needed to see if clinical and MR-tomographic outcome can be maintained beyond 24 months.

MRI following UKA: The component-bone interface.

BACKGROUND: Loosening is one of the major long-term failure modes in unicondylar knee arthroplasty (UKA). The aim of the study is to describe and characterize implant-bone interface of femoral and tibial components after UKA by means of magnet resonance imaging (MRI). MATERIAL AND METHODS: MRI tailored to reduce metallic artefact of the knee after medial UKA was performed in 10 patients as a pilot study. The component-bone interface at femoral and tibial components was evaluated by two independent investigators. They gave degree of confidence to their evaluation of each parameter on a five-point scale. Inter-observer reliability was determined. RESULTS: Artefacts provoked by the implants were rare. Inter-observer reliability and confidence were excellent for the femoral interface. They were lower at the tibial interface but results were still satisfactory. CONCLUSIONS: Tailored MRI allows reproducible analysis of the component-bone interface after UKA. It is helpful in assessment of suspected loosening after UKA.

Management of a metastasized high grade insulinoma (G3) with refractory hypoglycemia: case report and review of the literature.

Insulinomas represent the most common functional neuroendocrine tumor of the pancreas. They are usually solitary, benign, well differentiated (G1/G2) and curable by surgery. We describe the case of a 45 year old male Caucasian with a unique malignant, metastasized pancreatic insulinoma (Ki 67 of 70%, G3). To control excessive insulin production emanating in refractory hypoglycemia and growth of the highly proliferating tumor a multimodal therapeutic approach including the consecutive use of tumor debulking surgery, chemotherapy, TACE, SIRT, PRRT as well as a drug therapy with diazoxide, somatostatin analogs and everolimus was employed. Chemotherapy with carboplatin/etoposide plus everolimus provided the longest normoglycemic period. After progress chemotherapy with dacarbazine had the most positive effect, while debulking approaches such as surgery and liver directed therapies, as well as PRRT were less efficient with only transient success.

MR, CT, and PET imaging in pericardial disease.

Although echocardiography remains the standard diagnostic tool for identifying pericardial diseases, procedures with better delineation of morphology and heart function are often required. The pericardium consists of an inner visceral (epicardium) and outer parietal layer (pericardium), which constitute for the pericardial cavity. Pericardial effusion can occur as transudate, exudate, pyopneumopericardium, or hemopericardium. Potential causes are inflammatory processes, that is, pericarditis due to autoimmune or infective reasons, neoplasms, irradiation, or systemic disorders, chronic renal failure, endocrine, or metabolic diseases. Pericardial fat can mimic pericardial effusion. Using various image-acquisition sequences, MRI allows identifying and separating fluid and solid structures. Fast spin-echo T1-weighted sequences with black-blood preparation are favourably used for morphological evaluation. Fast spin-echo T2-weighted sequences, particularly with fat saturation, and short-tau inversion-recovery sequences are useful to visualize oedema and inflammation. For further tissue characterization, delayed inversion-recovery imaging is used. Therefore, image acquisition is performed at 5-20 min subsequent to contrast agent administration, the so-called technique of late gadolinium enhancement. Ventricular volumes and myocardial mass can be assessed accurately by steady-state free-precession sequences, which is required to measure cardiac function and ventricular wall stress. Constrictive pericarditis usually results from chronic inflammatory processes leading to increased stiffness, which impedes the slippage of both pericardial layers and thereby the normal cardiac filling. CT imaging can favourably assess pericardial calcification. Thus, MR and CT imaging allow a comprehensive delineation of the pericardium. Superior to echocardiography, both methods provide a larger field of view and depiction of the complete chest including abnormalities of the surrounding mediastinum and lungs. PET provides unique information on the in vivo metabolism of 18-fluorodeoxyglucose that can be superimposed on CT findings and is useful for identifying inflammatory processes or masses, for example neoplasms. These imaging techniques provide advanced information of anatomy and cardiac function to optimize the pericardial access, for example by the AttachLifter system, for diagnosis and treatment.

Identifying radiological needs of referring clinicians.

To provide prospective information about quality- and satisfaction-related product features in radiology, a customer-centered approach for acquiring clinicians' requirements and their prioritizations is essential. We introduced the Kano model for the first time in radiology to obtain such information. A Kano questionnaire, consisting of pairs of questions regarding 13 clinician requirements related to computed tomography (CT), magnetic resonance imaging (MRI) access and report turnaround time (RTT), was developed and administered. Each requirement was assigned a Kano category, and its satisfaction and dissatisfaction coefficients were calculated and presented in a Kano diagram. The data were stratified based on different clinics and on staff and resident clinicians. The time interval was evaluated between the completion of an examination and the first attempt to access the report by a clinician. Consultation for modality selection and scheduling and access to CT within 24 h and RTT within 8 to 24 h were considered as must-be requirements. Access to CT within 4 h and within 8 h, access to MRI within 8 h and within 24 h, and access to RTT within 4 h were one-dimensional requirements. The extension of operation time for CT or MRI, as well as MRI access within 4 h, was considered attractive. Eight out of nine clinics considered RTT within 8 h as a must-be requirement. There were differences in responses both among different clinics and between staff and resident clinicians. Access attempts to reports by clinicians in the first 4 h after the examination completion accounted for 65 % of CTs and 49 % of MRIs.

MRI after unicondylar knee arthroplasty: rotational alignment of components.

INTRODUCTION: This pilot study used magnet resonance imaging (MRI) to analyse the rotation of medial unicondylar knee arthroplasty (UKA) components and assessed how accurately the results could be reproduced. MATERIALS AND METHODS: Knee MRI using a special protocol to reduce metal artefact was performed in ten patients who had undergone medial UKA. Two independent investigators measured the rotation angle of femoral (zirconium) and tibial (cemented full-poly or cemented modular metal-backed) components applying different reference lines for the latter. Statistical analysis comprised tests for reliability, variance between measurement techniques, standard deviations and limits of agreement. RESULTS: For all methods tested, there was sufficient inter- and intra-observer reliability. Lowest variances were, however, found for the femoral epicondyles, for both femoral and tibial components. A tangent to the dorsal epicondyles of the tibia also gave reproducible results with low variances for the tibial component. DISCUSSION: Almost all applied measurement techniques were reproducible by statistical definition, although some of them resulted in substantial differences between both, observations and observers. A variance test helps to distinguish better between clinically useful and less accurate references. CONCLUSION: MRI allows good reproducible rotation analysis via the femoral epicondyles for both femoral and tibial UKA implants. For the tibia, the tibial tuberosity, the eminentia and the tibial epicondyles in particular were shown to be less reliable. The dorsal epicondyles seem to be most suitable for the tibial component.

Occurrence and positive predictive value of additional nonmass findings for risk stratification of breast microcalcifications in mammography.

PURPOSE: To assess the occurrence and positive predictive value of additional nonmass findings to stratify the risk of breast microcalcifications. METHODS: This retrospective evaluation included 278 lesions with vacuum- or image-guided hook-wire biopsy for suspicious microcalcifications. The lesions were categorized into exclusive microcalcifications and microcalcifications with focal asymmetry, tubular density or architectural distortion (ie, nonmass findings). To evaluate the utility of additional nonmass findings for risk stratification, outcome variables were positive predictive values and odds ratios for malignancy and invasive carcinoma. RESULTS: Forty-five of 278 microcalcification lesions (16%) were associated with nonmass findings: 28 focal asymmetries, 2 tubular densities, and 15 focal asymmetries in conjunction with tubular densities. Architectural distortion was observed in 28 of these cases. The odds ratio for additional nonmass findings relative to exclusive microcalcifications was 5.9 and was statistically significant (P < .00001). Architectural distortion was the most specific indicator for malignancy and invasiveness, with odds ratios of 6.5 (P = .0072) and 5.6 (P = .0214), respectively. CONCLUSIONS: Microcalcifications with nonmass findings were less frequent than exclusive microcalcifications but were more predictive for malignancy. Architectural distortion demonstrated the highest risk of malignancy and invasiveness. Assessment of additional nonmass findings might be useful for further risk stratification of microcalcifications, indications for additional imaging, and pretreatment considerations.

Characteristics of familial pancreatic cancer families with additional colorectal carcinoma.

Familial pancreatic cancer (FPC) is a rare hereditary tumor entity with broad phenotypic heterogeneity, including colorectal carcinoma (CRC) in some families. The underlying factors for this co-occurrence are still not well evaluated. FPC families in the National Case Collection of Familial Pancreatic Cancer with an additional occurrence of CRC were analyzed regarding the phenotype, genotype and recommendation for a clinical screening program. The total cohort of 272 FPC families included 30 (11%) families with at least one CRC case. The proportion of affected family members with PDAC was 16.1% (73/451) compared to 9.3% of family members with CRC (42/451, p < 0.01). Females were affected with PDAC in 49% (36/73) and CRC in 38% (16/42). The median age of PDAC was 63 compared to 66 years in CRC, whereas 8 (26.6%) of families had an early onset of PDAC and 2 (6.7%) of CRC. Seventeen families had 2 or more affected generations with PDAC and 6 families with CRC. Eleven (9.6%) of affected patients had both PDAC and CRC. Potentially causative germline mutations (2 ATM, 1 CDKN2a, 1 MLH1, 1 PALB2) were detected in 5 of 18 (27.7%) analyzed cases. These findings provide a step forward to include the phenotypic and genotypic characteristics of FPC-CRC families for the genetic counseling and management of these families. Nevertheless, results need to be verified in a larger patient cohort beforehand.

Kidney Hypertrophy in Living Kidney Donors and Their Corresponding Recipients.

BACKGROUND: In this long-term study we compared kidney volume changes and function between living kidney donors and their corresponding recipients via magnetic resonance imaging after 3 to 8 years post transplantation. METHODS: For measurement of the kidney volume in magnetic resonance imaging images we used 3DSlicer. Statistical analysis was performed via t test and correlation. RESULTS: A profound volume increase was observed in both transplanted and orthotopic kidney. The volume increase of the orthotopic kidneys was with 58 cm³ ± 23.8 cm³ SD (41%) greater than in the corresponding transplanted kidneys with 43 cm³ ± 36.9 cm³ SD (30%). CONCLUSIONS: This study detected a persistent volume increase in both orthotopic and transplanted kidneys after donation. Neither significant increases of hypertension or proteinuria were observable or could be correlated to renal hypertrophy.

Relevant prognostic factors in patients with stage IV small intestine neuroendocrine neoplasms.

There are few, but controversial data on the prognostic role of upfront primary tumour resection and mesenteric lymph node dissection (PTR) in patients with diffuse metastatic small intestinal neuroendocrine neoplasia (SI-NEN). Therefore, the prognostic role of PTR and other factors was determined in this setting. This retrospective cohort study included patients with stage IV SI-NETs with unresectable distant metastases without clinical and radiological signs of acute bowel obstruction or ischaemia. Patients diagnosed from January 2002 to May 2020 were retrieved from a prospective SI-NEN database. Disease specific overall survival (OS) was analysed with regard to upfront PTR and a variety of other clinical (e.g., gender, age, Hedinger disease, carcinoid syndrome, diarrhoea, laboratory parameters, metastatic liver burden, extrahepatic and extra-abdominal metastasis) and pathological (e.g., grading, mesenteric gathering) parameters by uni- and multivariate analysis. A total of 138 patients (60 females, 43.5%) with a median age of 60 years, of whom 101 (73%) underwent PTR and 37 (27%) did not, were included in the analysis. Median OS was 106 (95% CI: 72.52-139.48) months in the PTR group and 52 (95% CI: 30.55-73.46) in the non-PTR group (p = 0.024), but the non-PTR group had more advanced metastatic disease (metastatic liver burden ≥50% 32.4% vs. 13.9%). There was no significant difference between groups regarding the rate of surgery for bowel complications during a median follow-up of 51 months (PTR group 10.9% and non-PTR group 16.2%, p = 0.403). Multivariate analysis revealed age < 60 years, normal C-reactive protein (CRP) at baseline, absence of diarrhoea, less than 50% of metastatic liver burden, and treatment with PRRT as independent positive prognostic factors, whereas PTR showed a strong tendency towards better OS, but level of significance was missed (p = 0.067). However, patients who underwent both, PTR and peptide radioreceptor therapy (PRRT) had the best survival compared to the rest (137 vs. 73 months, p = 0.013). PTR in combination with PRRT significantly prolongs survival in patients with stage IV SI-NEN. Prophylactic PTR does also not result in a lower reoperation rate compared to the non-PTR approach regarding bowel complications.

Combined Focused Next-Generation Sequencing Assays to Guide Precision Oncology in Solid Tumors: A Retrospective Analysis from an Institutional Molecular Tumor Board.

BACKGROUND: Increasing knowledge of cancer biology and an expanding spectrum of molecularly targeted therapies provide the basis for precision oncology. Despite extensive gene diagnostics, previous reports indicate that less than 10% of patients benefit from this concept. METHODS: We retrospectively analyzed all patients referred to our center's Molecular Tumor Board (MTB) from 2018 to 2021. Molecular testing by next-generation sequencing (NGS) included a 67-gene panel for the detection of short-sequence variants and copy-number alterations, a 53- or 137-gene fusion panel and an ultra-low-coverage whole-genome sequencing for the detection of additional copy-number alterations outside the panel's target regions. Immunohistochemistry for microsatellite instability and PD-L1 expression complemented NGS. RESULTS: A total of 109 patients were referred to the MTB. In all, 78 patients received therapeutic proposals (70 based on NGS) and 33 were treated accordingly. Evaluable patients treated with MTB-recommended therapy (n = 30) had significantly longer progression-free survival than patients treated with other therapies (n = 17) (4.3 vs. 1.9 months, p = 0.0094). Seven patients treated with off-label regimens experienced major clinical benefits. CONCLUSION: The combined focused sequencing assays detected targetable alterations in the majority of patients. Patient benefits appeared to lie in the same range as with large-scale sequencing approaches.

Revision of tibial TKA components: bone loss is independent of cementing type and technique: an in vitro cadaver study.

BACKGROUND: Different bone cements and various cementation techniques can lead to different bone loss in revision surgery. We investigated the degree of tibial bone loss depending on different cements and techniques. METHODS: 30 tibia specimens were matched into three groups (10 each). In all cases Genesis II tibia component were implanted. In two groups, the tibia base plate alone was cemented with Palacos® R+G and Refobacin® Bone Cement R. In the third group, both tibial base plate and tibial stem were cemented with Palacos® R+G. Afterwards, the specimens were axial loaded with 2000 N for 10,000 cycles. Tibial components were explanted and the required time to explantation was recorded. Bone loss after explantation was measured by CT. RESULTS: On CT, there was no significant difference in bone loss between cementing techniques (p = 0.077; 95% CI -1.14 - 21.03) or the cements themselves (p = 0.345; 95% CI -6.05 - 16.70). The required time to explantation was 170.6 ± 54.89, 228.7 ± 84.5, and 145.7 ± 73.0 seconds in the first, second, and third groups, respectively. CONCLUSIONS: Cement technique and type do not influence tibial bone loss in simulated revision surgery of the tibial component in knee arthroplasty.

Initial stability of tibial components in primary knee arthroplasty. A cadaver study comparing cemented and cementless fixation techniques.

The purpose of this roentgen stereophotogrammetric analysis (RSA) study was to evaluate the initial stability of cemented and cementless tibial components in vitro. Twenty tibia specimens were matched into two groups. In the first group, the tibial trays were cemented superficially and in the second group cementless fixation with stem and screws was performed. An axial load of 2000 N for 1000 and 10,000 cycles was applied onto the specimens and RSA was performed. The experimental results after 1000 cycles showed a higher migration with significant differences for the parameters maximum lift off (p = 0.011) and maximum total point motion (p = 0.002) in the cementless group. After 10,000 cycles, the migration in the cementless group increased significantly for maximum lift off (p = 0.043), maximum subsidence (p = 0.045) and maximum total point motion (p = 0.013). The higher migration rates in the cementless group demonstrate a lower initial mechanical stability of cementless tibial components which can cause an early component loosening.

Pull-out strength evaluation of cement augmented iliac screws in osteoporotic spino-pelvic fixation.

INTRODUCTION: Spino-pelvic fixation has been widely accepted for surgical treatment of sacral tumor, scoliosis surgery and pelvic fractures. Cement augmentation of screws is an option to improve implant stability in osteoporotic bone quality. Aim of the present study is to compare iliac screw fixation without cement fixation and two cement application options in a biomechanical testing. HYPOTHESIS: Cement augmentation of iliac screws leads to superior pull-out strength. MATERIAL AND METHODS: Thirty female and osteoporotic human iliac bones were used. Three operation treatment groups were generated: Screw fixation (cannulated screws) without cement augmentation [Operation treatment (OT) A], screw fixation with cement augmentation before screw placement (cannulated screws) (OT B) and screw fixation with perforated screws and cement augmentation after screw placement (OTC). Pull-out tests were performed with a rate of 6mm/min. A load versus displacement curve was generated. Maximum pull-out force (N) was measured in the load-displacement curve. RESULTS: Paired group 1 (OT A vs. OT B): Screw fixation without cement augmentation: 592.6N±335.07 and screw fixation with cement augmentation before screw placement: 996N±287.43 (p=0.0042). Paired group 2 (OT A vs. OT C): screw fixation without cement augmentation: 716.2N±385.86 and fenestrated screw fixation with cement augmentation after screw placement: 1324.88N±398.76 (p=0.0489). Paired group 3 (OT B vs. OT C): Screw fixation with cement augmentation before screw placement: 1077.2±486.66 and fenestrated screw fixation with cement augmentation after screw placement: 1298.2N±726.19 (p=0.3286). DISCUSSION: Regarding iliac screw fixation for spino-pelvic ostesynthesis in osteoporotic bone, cement augmentation is significantly superior to solid iliac screw fixation respecting pull-out-strength. Nevertheless, further biomechanical studies are needed to verify these findings. LEVEL OF EVIDENCE: Not applicable; biomechanical cadaver study.

The German National Case Collection for Familial Pancreatic Carcinoma (FaPaCa)­Knowledge Gained in 20 Years.

BACKGROUND: Familial pancreatic carcinoma (FPC) is a rare hereditary tumor syndrome with a heterogeneous clinical phenotype. The study of FPC also contributes to a better understanding of the more common sporadic pancreatic ductal adenocarcinoma (PDAC). We report on the past 20 years' experience of the German National Case Collection for Familial Pancreatic Carcinoma (FaPaCa) of the German Cancer Aid (Deutsche Krebshilfe). METHODS: From 1999 onward, families in which at least two first-degree relatives had PDAC, and which did not meet the criteria for any other tumor syndrome, have been entered into the FaPaCa registry and analyzed both clinically and with molecular genetic techniques. Persons at risk are offered the opportunity to participate in an early detection program. RESULTS: From June 1999 to June 2019, 227 families (a total of 2579 persons) met the criteria for entry into the FaPaCa registry. PDAC was the sole tumor entity present in 37% of the families (95% confidence interval [31.1; 44.1]); in the remaining 63% [55.9; 68.9], other tumor types were present as well, particularly breast cancer (70 families, 31% [24.9; 37.3]), colon carcinoma (25 families, 11% [7.3; 15.8]) , and melanoma (22 families, 9.7% [6.2; 14.3]). The mode of inheritance of PDAC was autosomal dominant in 72% [65.5; 77.6] of the families. Predisposing germ-line mutations were found in 25 of the 150 (16.7%) families studied, in the following genes: BRCA2 (9 families), CDKN2A (5 families), PALB2 (4 families), BRCA1 (3 families), ATM (2 families), and CHEK2 (2 families). The early detection program revealed high-grade cancer precursor lesions or a PDAC in 5 of the participating 110 persons at risk (4.5%, [1.5; 10.3] during a period of observation of at least five years. CONCLUSION: The care of families with FPC is complex and should be provided in centers with the necessary expertise. Prospective, controlled longitudinal studies are needed to determine whether the screening of persons at risk for PDAC truly lessens mortality and is cost-effective.