Trend Shift in the Cause of Revision Total Knee Arthroplasty over 17 Years

Background@#The number of revision total knee arthroplasty (TKA) has been increasing. Although many studies have analyzed the causes of revision TKA in Western countries, a limited number of studies have analyzed changes in causes of or trends in revision TKA in Asia. This study analyzed and determined the frequency and causes of failures after TKA in our hospital. We also analyzed the differences and trends over the past 17 years. @*Methods@#A total of 296 revision TKAs performed in a single institution from 2003 to 2019 were analyzed. During the 17-year study period, patients who had undergone primary TKA between 2003 and 2011 were classified into a past group, while those who had undergone primary TKA from 2012 to 2019 were classified into a recent group. A revision performed within 2 years after primary TKA was defined as early revision. Further, differences in causes of revision TKA according to the interval from primary TKA to revision TKA were determined. The causes of revision TKA were analyzed through a comprehensive analysis of patients’ medical records. @*Results@#Overall, infection was the most common cause of failure (151/296 cases, 51.0%). Compared to the past group, the recent group had a relatively higher proportion of patients undergoing revision TKA for mechanical loosening (past group, 19.1% vs.recent group, 31.9%) and instability (11.2% vs. 13.5%) and a relatively lower proportion of patients undergoing revision TKA for infection (56.2% vs. 48.8%), polyethylene (PE) wear (9.0% vs. 2.9%), osteolysis (2.2% vs. 1.9%), and malalignment (2.2% vs. 1.0%).On comparison according to the interval from primary TKA to revision TKA, the rate of infection relatively decreased, whereas the rate of mechanical loosening and instability relatively increased in the late revision TKA compared to the early revision TKA. @*Conclusions@#Infection and aseptic loosening were the most common reasons of revision TKA in both past and recent groups.Compared to the past, revision TKA due to PE wear has decreased significantly and revision TKA due to mechanical loosening has relatively increased recently. Orthopedic surgeons need to be aware of recent trends in mechanisms of failure and should try to recognize and address the probable causes in TKA

Development and Performance Evaluation of a Quantitative Reverse Transcription PCR Kit for the Determination of prohibitin Gene Expression

Background@#Prohibitin (PHB) regulates intracellular signal pathways, transcription, and cell cycles. Aberrant expression of the PHB gene is known to be related totumorigenesis, tumor progression, and chronic metabolic and inflammatory diseases. The present study aimed to develop a one-step quantitative reverse transcription PCR (RT-qPCR) kit for quantifying PHB mRNA levels and evaluate its performance in the laboratory. @*Methods@#TaqMan chemistry was used to develop the one-step PHB1 and PHB2 RT-qPCR kit. Normal peripheral blood cells from healthy individuals (N=20) and leukemia cells from patients initially diagnosed with acute myeloid leukemia (AML, N=20), chronic myeloid leukemia (CML, N=13), and acute lymphoid leukemia (ALL, N=7) were enrolled to evaluate the laboratory performance of the kit using commercially available total human RNA controls. @*Results@#The intra-assay and inter-assay precision of the kit developed in this study was less than 2%. The distribution of PHB1 mRNA expression of AML, CML, and ALL was 0.898-0.993 (median: 0.936), 0.817-0.976 (0.918), and 0.844-1.074 (0.973), respectively. The distribution of PHB2 mRNA expression of AML, CML, and ALL was 0.957-1.024 (median: 0.985), 0.988-1.047 (1.002), and 0.937-1.059 (1.004), respectively. The sensitivity, specificity, positive and negative predictive value, and test effectiveness of the developed PHB1 and PHB2 kit were greater than 50% for each parameter. @*Conclusions@#Our developed kit would be useful for diagnosing leukemia as well as detecting residual disease. Additionally, this kit could be used for monitoring and conducting molecular pathophysiological studies of obesity, metabolic, and inflammatory diseases.

Fluoranthene-Induced Cytotoxicity and Direct Effect of Aryl Hydrocarbon Receptor Antagonist on Hematopoietic Stem Cell Differentiation

No abstract available.

Spectrum of mitochondrial genome instability and implication of mitochondrial haplogroups in Korean patients with acute myeloid leukemia

BACKGROUND: Mitochondrial DNA (mtDNA) mutations may regulate the progression and chemosensitivity of leukemia. Few studies regarding mitochondrial aberrations and haplogroups in acute myeloid leukemia (AML) and their clinical impacts have been reported. Therefore, we focused on the mtDNA length heteroplasmies minisatellite instability (MSI), copy number alterations, and distribution of mitochondrial haplogroups in Korean patients with AML. METHODS: This study investigated 74 adult patients with AML and 70 controls to evaluate mtDNA sequence alterations, MSI, mtDNA copy number, haplogroups, and their clinical implications. The hypervariable (HV) control regions (HV1 and HV2), tRNA(leu1)gene, and cytochrome b gene of mtDNA were analyzed. Two mtDNA minisatellite markers, 16189 poly-C (¹⁶¹⁸⁴CCCCCTCCCC¹⁶¹⁹³, 5CT4C) and 303 poly-C (³⁰³CCCCCCCTCCCCC³¹⁵, 7CT5C), were used to examine the mtDNA MSI. RESULTS: In AML, most mtDNA sequence variants were single nucleotide substitutions, but there were no significant differences compared to those in controls. The number of mtMSI patterns increased in AML. The mean mtDNA copy number of AML patients increased approximately 9-fold compared to that of controls (P < 0.0001). Haplogroup D4 was found in AML with a higher frequency compared to that in controls (31.0% vs. 15.7%, P=0.046). None of the aforementioned factors showed significant impacts on the outcomes. CONCLUSION: AML cells disclosed more heterogeneous patterns with the mtMSI markers and had increased mtDNA copy numbers. These findings implicate mitochondrial genome instability in primary AML cells. Therefore, mtDNA haplogroup D4 might be associated with AML risk among Koreans.

The Clinical and Radiological Results of Vancouver Type B1 and C Periprosthetic Fractures

PURPOSE: The purpose of this study is to evaluate the clinical and radiologic results of plate fixation in the Vancouver B1 and C periprosthetic femoral fracture (PFF). MATERIALS AND METHODS: Twenty patients who had sustained a Vancouver type B1 and C periprosthetic fracture after hip arthroplasty (years 2002-2012) were identified. The mean age was 66.0 years (range, 43-85 years) and the mean follow-up duration of the group was 38 months (range, 12-102 months). The dynamic compression plate (DCP) group included 12 patients and the locking compression plate (LCP) group included eight patients. Harris hip score (HHS) and walking ability, knee joint range of motion (ROM) were compared before injury and last follow-up. Fracture union rate and period were compared. RESULTS: The mean HHS score was 90.7 (64-96). There was no statistical difference between the two groups. At the last follow-up, knee joint ROM was 103.3degrees (105degrees-140degrees) in the DCP group and 118.4degrees (110degrees-140degrees) in the LCP group, showing good results in the LCP group (p=0.043). No significant difference in the fracture union rate and union periods was observed between the two groups. CONCLUSION: A better result for the postoperative knee flexion exercise capacity was observed in the LCP group. Use of LCP plate fixation is a good option in management of Vancouver classification B1 and C PFF.

Bone Transport for Reconstruction in Benign Bone Tumors

BACKGROUND: The aim of this study was to assess the results of using the Ilizarov apparatus to transport bones in the treatment of benign bone tumors. METHODS: Seven patients (six males and one female) with benign bone tumors were treated by bone transport with an Ilizarov apparatus at our institution. Their mean age at surgery was 14.4 years (range, 4.8 to 36.9 years). The histological diagnoses were osteofibrous dysplasia (4), giant-cell tumor (1), intraosseous cavernous hemangioma (1), and aneurysmal bone cyst (1). Three radiological indices were used for evaluating the results: an external fixation index, a distraction index, and a maturation index. The bone and functional results were evaluated according to the Association for the Study and Application of the Method of Ilizarov classification. RESULTS: Five patients had bone union at the reconstructed site, one patient had a local recurrence, and the other had a nonunion at the docking site. The mean length of distraction was 7.3 cm (range, 5.1 to 12.1 cm). The mean external fixation index was 26.0 day/cm (range, 19.8 to 32.5 day/cm), the distraction index was 9.6 day/cm (range, 6.8 to 12.0 day/cm), and the maturation index was 14.9 day/cm (range, 8.0 to 22.5 day/cm). Ultimately, the bone and the functional results were rated excellent in six cases and good in one case. CONCLUSIONS: Bone transport using the Ilizarov apparatus is a good treatment option in patients with bone defects after the resection of an active or aggressive benign bone tumor.

Osteosarcoma with Adenocarcinoma of Lung in Li-Fraumeni Syndrome: A Case Report / 대한골관절종양학회지

Li-Fraumeni syndrome (LFS) is an autosomal dominant hereditary disorder characterised by a variety of different tumor types in children and young adults. That contains with a germline mutation in the tumor suppressor gene Tumor Protein p53 (TP53). That is extremely rare. Furthermore, this is sometimes overlooked. Here, we report a case of LFS which was confirmed by mutational analysis of the p53 gene. Also, literature review is intended to improve understanding of this disease entity.