Joint effusions are most frequently caused by osteoarthritis, trauma, an infection process or an autoimmune disease. The development of joint effusion due to a tumor process is rare but should be taken into consideration in the diagnostics. Joint effusions are examined mostly by means of microbiology to rule out or confirm pyogenic synovitis. These standard processes may take up to several days. The article presented here describes a unique case of a 74-year-old female diagnosed with a generalized malignant process according to a cytological-energy analysis and an immunocytochemical examination of a malignant joint effusion caused by femoral condyle metastasis. Other widely-used imaging methods such as X-ray, full-body CT scan and also laboratory examinations confirmed the malignancy and the origin. A cytological-energy analysis and an immunocytochemical examination can expedite the diagnostic process, can outline the processes happening in the joint and can indicate further examinations and subsequent therapy. The use of these laboratory methods appears to be a helpful diagnostic option to obtain additional information about a joint effusion, including the information about an ongoing malignant process. In our case report, they helped to confirm the typing of the tumor within three days, without the need for a metastasis biopsy. In appropriate cases, synovial fluid can play a role in tumor diagnostics.

Background Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection and the resulting coronavirus 2019 disease (COVID‐19) have spread all around the world since 2019 and have affected millions of people. The development of COVID‐19 vaccines helped to decelerate the spread of the virus. However, as in the case of vaccines against other infectious diseases, adverse events can also present with COVID‐19 vaccines. Case Presentation We report here a rare case of a 53‐year‐old man with knee‐joint synovitis, after the first dose of messenger RNA vaccine, with no fever and a negative COVID‐19 reverse transcription polymerase chain reaction test. During a clinical examination the suspicion of pyogenic arthritis was excluded by blood tests and by a complex joint effusion examination, including a microbiological and cytological‐energy analysis of the synovial fluid. The treatment received by our patient consisted of 3 doses of dexamethasone administered intravenously over a period of 3 days. All the symptoms improved after this therapy, and in the 3‐week follow‐up period we recorded full recovery with no consequences. Conclusion Case reports on patients undergoing COVID‐19 vaccination should be examined in order to detect rare and long‐term side‐effects. This is the first report to present the outcomes of an ultrastructural analysis of post‐vaccination synovitis.

Traumatic anterior dislocation of a total knee arthroplasty (TKA) is an extremely rare occurrence. There are only a few known cases of this type of dislocation which discuss the high risk of a neurovascular complication. This article describes a traumatic anterior dislocation of the TKA with a severe vascular lesion in a 75-year-old severely comorbid patient. Further complications led to the development of a compartment syndrome. Despite the repeated effort in performing a well-functioning anastomosis of the popliteal artery tear by the vascular surgeon, reperfusion of the lower extremity was not effective. Furthermore, multiorgan system failure due to the reperfusion syndrome evolved. This led to an above-knee amputation as a lifesaving procedure. Despite thorough intensive care therapy, the patient did not survive this complication. Presently there are no reported cases with such severe complications after the luxation of a previously well-functioning TKA leading to the death of the patient.

Our aim was to study the expression of hypoxia-related proteins as a possible regulatory pathway in the contracted side tissue of relapsed clubfoot. We compared the expression of hypoxia-related proteins in the tissue of the contracted (medial) side of relapsed clubfoot, and in the tissue of the non-contracted (lateral) side of relapsed clubfoot. Tissue samples from ten patients were analyzed by immunohistochemistry and image analysis, Real-time PCR and Mass Spectrometry to evaluate the differences in protein composition and gene expression. We found a significant increase in the levels of smooth muscle actin, transforming growth factor-beta, hypoxia-inducible factor 1 alpha, lysyl oxidase, lysyl oxidase-like 2, tenascin C, matrix metalloproteinase-2, matrix metalloproteinase-9, fibronectin, collagen types III and VI, hemoglobin subunit alpha and hemoglobin subunit beta, and an overexpression of ACTA2, FN1, TGFB1, HIF1A and MMP2 genes in the contracted medial side tissue of clubfoot. In the affected tissue, we have identified an increase in the level of hypoxia-related proteins, together with an overexpression of corresponding genes. Our results suggest that the hypoxia-associated pathway is potentially a factor contributing to the etiology of clubfoot relapses, as it stimulates both angioproliferation and fibroproliferation, which are considered to be key factors in the progression and development of relapses.

No abstract