Extraarticular Knee Resection for Sarcomas with Preservation of the Extensor Mechanism: Surgical Technique and Review of Cases

Background: Sarcomas in or contaminating the knee are rare but extremely challenging to treat. Complete resection of the joint is necessary, and often the entire extensor mechanism is removed as well. Reconstruction of the knee is challenging, and the resulting function may be compromised. Description of technique: We describe a surgical technique of extraarticular resection of the knee while preserving the extensor mechanism combined with prosthetic reconstruction. The medial and lateral retinaculum is prepared such that it allows extraarticular placement of K-wires that are driven through the patella and the proximal tibia, serving as in situ guides for the osteotomies. Patients and Methods: We retrospectively reviewed 11 patients with sarcomas contaminating the knee. The minimum followup was 14months (mean, 38months; range, 14-80months). Results: At last followup patients had a mean flexion of 88° (range, 65°-120°). We observed no complications related to the extensor mechanism, and there was one local recurrence. Conclusions: We believe extraarticular resection of the knee with preservation of the extensor mechanism is a reasonable treatment option for intraarticular sarcomas with functional scores comparable to those for patients having intraarticular resections. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidenc

Ist Anonymisierung Fälschung? Ein Kommentar zu Stefan Kühl

Gibt es Situationen, in denen ein Forscher Daten fälschen darf oder sogar fälschen sollte? Stefan Kühl scheint das zu meinen, wenn er seinen Beitrag »Zwischen Präzision und Anonymisierung. Wie weit muss man bei der Verfälschung wissenschaftlicher Daten gehen?«, erschienen in der SOZIOLOGIE, mit dem Satz beginnt: »Ich habe in meinen wissenschaftlichen Arbeiten Daten verfälscht.« (Kühl 2020: 62) Natürlich weiß er als verbeamteter Hochschullehrer, dass dies eine gefährliche Aussage ist, die – wenn sie zuträfe – im schlimmsten Fall mit dem Verlust seiner Professur geahndet werden könnte. Tatsächlich will er mit dieser provozierenden Aussage auf ein Dilemma der empirischen Sozialforschung zwischen dem Fälschungsverbot von Daten und dem Anonymisierungsgebot hinweisen

Extraarticular Knee Resection for Sarcomas with Preservation of the Extensor Mechanism: Surgical Technique and Review of Cases

BACKGROUND: Sarcomas in or contaminating the knee are rare but extremely challenging to treat. Complete resection of the joint is necessary, and often the entire extensor mechanism is removed as well. Reconstruction of the knee is challenging, and the resulting function may be compromised. DESCRIPTION OF TECHNIQUE: We describe a surgical technique of extraarticular resection of the knee while preserving the extensor mechanism combined with prosthetic reconstruction. The medial and lateral retinaculum is prepared such that it allows extraarticular placement of K-wires that are driven through the patella and the proximal tibia, serving as in situ guides for the osteotomies. PATIENTS AND METHODS: We retrospectively reviewed 11 patients with sarcomas contaminating the knee. The minimum followup was 14 months (mean, 38 months; range, 14-80 months). RESULTS: At last followup patients had a mean flexion of 88° (range, 65°-120°). We observed no complications related to the extensor mechanism, and there was one local recurrence. CONCLUSIONS: We believe extraarticular resection of the knee with preservation of the extensor mechanism is a reasonable treatment option for intraarticular sarcomas with functional scores comparable to those for patients having intraarticular resections. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence

Accuracy of Patient Specific Cutting Blocks in Total Knee Arthroplasty

Background. Long-term survival of total knee arthroplasty (TKA) is mainly determined by optimal positioning of the components and prosthesis alignment. Implant positioning can be optimized by computer assisted surgery (CAS). Patient specific cutting blocks (PSCB) seem to have the potential to improve component alignment compared to the conventional technique and to be comparable to CAS. Methods. 113 knees were selected for PSI and included in this study. Pre- and postoperative mechanical axis, represented by the hip-knee-angle (HKA), the proximal tibial angle (PTA), the distal femoral angle (DFA), and the tibial slope (TS) were measured and the deviation from expected ideal values was calculated. Results. With a margin of error of ±3°, success rates were 81.4% for HKA, 92.0% for TPA, and 94.7% for DFA. With the margin of error for alignments extended to ±4°, we obtained a success rate of 92.9% for the HKA, 98.2% for the PTA, and 99.1% for the DFA. The TS showed postoperative results of 2.86 ± 2.02° (mean change 1.76 ± 2.85°). Conclusion. PSCBs for TKA seem to restore the overall leg alignment. Our data suggest that each individual component can be implanted accurately and the results are comparable to the ones in CAS

Differences in Distribution and Detection Rate of the [68Ga]Ga-PSMA Ligands PSMA-617, -I&T and -11—Inter-Individual Comparison in Patients with Biochemical Relapse of Prostate Cancer

The biochemical relapse of prostate cancer is diagnostically challenging but of high clinical impact for subsequent patient treatment. PET/CT with radiolabeled PSMA ligands outperforms conventional diagnostic methods in the detection of tumor recurrence. Several radiopharmaceuticals were and are available for use. The aim of this study was to investigate whether the routinely applied [68Ga]Ga-PSMA ligands PSMA-617, -I&T and -11 (HBED-CC) differ in physiological and pathological distribution, or in tumor detection rate. A retrospective evaluation of 190 patients (39 patients received PSMA-617, 68 patients PSMA-I&T and 83 patients PSMA-11) showed significant differences in tracer accumulation within all organs examined. The low retention within the compartments blood pool, bone and muscle tissue is a theoretical advantage of PSMA-11. Evaluation of tumor lesion uptake and detection rate did not reveal superiority of one of the three radiopharmaceuticals, neither in the whole population, nor in particularly challenging subgroups like patients with very low PSA levels. We conclude that all three [68Ga]Ga-PSMA ligands are equally feasible in this clinically important scenario, and may replace each other in case of unavailability or production restrictions

Discrete populations of isotype-switched memory B lymphocytes are maintained in murine spleen and bone marrow

At present, it is not clear how memory B lymphocytes are maintained over time, and whetheronly as circulating cells or also residing in particular tissues. Here we describe distinctpopulations of isotype-switched memory B lymphocytes (Bsm) of murine spleen and bonemarrow, identified according to individual transcriptional signature and B cell receptorrepertoire. A population of marginal zone-like cells is located exclusively in the spleen, while apopulation of quiescent Bsm is found only in the bone marrow. Three further residentpopulations, present in spleen and bone marrow, represent transitional and follicular B cellsand B1 cells, respectively. A population representing 10-20% of spleen and bone marrowmemory B cells is the only one qualifying as circulating. In the bone marrow, all cells individuallydock onto VCAM1+ stromal cells and, reminiscent of resident memory T and plasmacells, are void of activation, proliferation and mobility.Peer Reviewe