The advantage of navigation for knee with lateral femoral bowing in total knee arthroplasty.

PURPOSE: We have analyzed the surgical outcomes of primary total knee arthroplasty (TKA) using computer-assisted (CA) navigation in terms of postoperative coronal alignment depending on preoperative lateral femoral bowing. METHODS: We conducted a retrospective study of patients who have undergone navigated primary TKA from January 2016 through January 2020. Two hundred and ninety-nine cases with lateral femoral bowing of 3° or less were assigned to group 1, 95 cases of lateral femoral bowing between 3° and 5° were assigned to group 2, and 89 cases with lateral femoral bowing of more than 5° were assigned to group 3. The postoperative mechanical hip-knee-ankle (mHKA) angle was measured from scanograms, which were taken 3 months after surgery. The appropriate range of coronal alignment was set as 0 ± 3°. RESULTS: The number of outliers of mHKA occurred was 31 cases (10.4%) in group 1, 17 cases (17.9%) in group 2, and 17 cases (19.1%) in group 3. There was a significant correlation between the degree of lateral femoral bowing and the occurrence rate of mHKA outliers. Multiple variables logistic regression analysis showed occurrence rate of outliers in group 3 to be 2.04 times higher than group 1. After adjusting the patient's age, sex, body mass index, and preoperative HKA deformity, the occurrence rate of outliers in group 3 was still 1.96 times higher than group 1. CONCLUSION: The benefit of CA navigation during TKA in obtaining coronal alignment within 0 ± 3° may be lessened when the preoperative lateral femoral bowing is severely advanced.

IgG Seroprevalence of COVID-19 among Individuals without a History of the Coronavirus Disease Infection in Daegu, Korea.

BACKGROUND: Seroprevalence studies of coronavirus disease 2019 (COVID-19) from many countries have shown that the number of undiagnosed missing cases is much larger than that of confirmed cases, irrespective of seroprevalence levels. Considering the strategy of Korea entailing massive testing and contact tracing from the beginning of epidemic, the number of undiagnosed missing cases in Korea may be negligible. This study was conducted to estimate the seroprevalence of COVID-19 among individuals who were never diagnosed with COVID-19 in Daegu, the epicenter of COVID-19 epidemic in Korea. METHODS: Serologic testing for immunoglobulin G antibody based on immunochromatographic assay was conducted in 103 patients and 95 guardians aged 18 to 82 years without any history of COVID-19 diagnosis, who visited outpatient clinics of a single university-affiliated hospital from May 25 to June 5, 2020. RESULTS: The estimated seroprevalence was 7.6% (95% confidence interval, 4.3%-12.2%) with 15 positive cases. Among them, only one had a polymerase chain reaction (PCR)-confirmed case among their close contacts and 13 did not experience COVID-19-related symptoms. Seroprevalence was similar between patients and guardians. Based on this figure, the number of undiagnosed missing cases in Daegu was estimated to be a dozen times more than the number of confirmed cases based on PCR testing. CONCLUSION: Despite the limitation of a small and unrepresentative sample, this is the first study on seroprevalence of COVID-19 in Korea. Our study suggested that the number of undiagnosed missing cases was substantial even with the stringent strategy adopted in Korea, similar to that of other countries.

Embolization for intractable spontaneous hemarthrosis of the knee joint in the elderly patient: Case report.

RATIONALE: Several case reports about the diagnostic and therapeutic approaches of hemarthrosis after total knee arthroplasty using angiogram have been reported, owing to the probability of bleeding caused by vascular injuries. However, there were only few cases of spontaneous hemarthrosis of the knee joint in the elderly patient that have not undergone total knee arthroplasty that have been previously reported. PATIENTS CONCERNS: An 82-year-old male presented to our outpatient department with acute left knee pain. He had no history of trauma. The patient had under gone several times of therapeutic arthrocentesis for treatment of left knee joint effusion at a local clinic. DIAGNOSIS: Arthroscopic examination was performed at the local clinic and was not able to reveal any focus of intra-articular bleeding. We consulted this case with the department of radiology to angiographically find out abnormalities of the genicular arteries. Angiographs showed hyper vascularity of the superior and inferior lateral genicular artery, and superior medial genicular artery. INTERVENTION: One-step embolization using micro-catheter and 50 to 150 µm gelfoam particles was conducted. The hypervascular findings shown on angiogram were markedly subsided after embolization. OUTCOMES: Until 1 year after embolization, there were no signs of recurrence on outpatient follow-up sessions LESSONS:: Degenerative changes of the genicular arteries may be a cause of spontaneous knee joint hemarthrosis in the elderly patients. Angiographic diagnosis and treatment may be effective for such cases.

Acquisition of coronal alignment according to the degree of varus deformity in total knee arthroplasty using computer-assisted navigation.

PURPOSE: We have analyzed the surgical outcomes of primary total knee arthroplasty (TKA) using computer-assisted navigation that were performed by a single surgeon in terms of postoperative coronal alignment depending on preoperative varus deformity. METHODS: We conducted a retrospective study of patients who have undergone navigated primary TKA from January 2016 through December 2019. Two hundred and fifty-six cases with varus deformity of 10° or less were assigned to group 1, and 216 cases with varus deformity of more than 10° were assigned to group 2. The postoperative mechanical hip-knee-ankle (mHKA) angle was measured from scanograms which were taken preoperatively and 3 months after surgery. The postoperative mHKA angle was targeted to be 0°, and the appropriate range of coronal alignment was set as 0 ± 3°. RESULTS: The Pearson correlation showed a significant correlation with the degree of preoperative varus deformity and with the absolute error of postoperative mHKA (p = 0.01). Among all patients, 64 cases (13.6%) were detected as outliers (mHKA > 0° ± 3°) at 3 months after surgery. Of the 64 cases, 25 cases (9.8%) were affiliated to group 1 and 39 cases (18.1%) were affiliated to group 2. Group 2 showed significantly higher occurrence of outliers than group 1 (p = 0.01). Multiple variables logistic regression analysis, which analyzed the difference in the occurrence rate of outliers (mHKA > 0° ± 3°), showed that the occurrence rate of group 2 was 2.04 times higher than group 1. After adjusting for patient's age, gender, and body mass index, the occurrence rate of outliers in group 2 was 2.01 times higher than group 1. CONCLUSION: The benefit of computer-assisted navigation during TKA in obtaining coronal alignment within 0 ± 3° may be lessened when the preoperative varus deformity is severely advanced.

The Relationship between Body Fat Percent and Bone Mineral Density in Korean Adolescents: The Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1), 2010.

BACKGROUND: The relationships of total and regional body fat percent with bone mineral density (BMD) in Korean adolescents were examined using the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1), 2010. METHODS: Body fat percent at whole body (WBFP), trunk (TBFP), and extremities (both upper and lower extremities fat mass/body weight, EBFP), ratio of trunk fat mass to extremities fat mass (TEFR), and BMD at whole body, total femur, and lumbar spine were measured by dual energy X-ray absorptiometry in a population-based sample of 433 boys and 362 girls, aged 12 to 18 years. The analyses were conducted using linear regression analysis with complex sampling design. RESULTS: After adjusting for confounders such as age, height, weight, serum 25-(OH) vitamin D concentration, energy intake, calcium intake, physical activity, and menarche status for girls, WBFP, TBFP, and EBFP were inversely associated with whole and regional BMD in both sexes (P < 0.05). TEFR was positively associated with whole and regional BMD in boys after adjusting for confounders, while it was negatively associated in girls (P < 0.05). However, the associations were non-significant when bone mass-free lean mass was adjusted instead of bodyweight except for a positive association between TEFR and BMD in boys. CONCLUSION: In Korean adolescents, total and regional body fat percent is not independently associated with BMD after adjusting for bone mass-free lean mass but higher fat in trunk as compared to extremities may be protective for BMD in boys.