PurposeTo identify the modes of failure after total knee arthroplasty (TKA) in patients >55 years of age and to compare with those >55 years of age in patients who underwent revision TKA.Materials and MethodsWe retrospectively reviewed 256 revision TKAs among patients who underwent TKA for knee osteoarthritis between January 1992 and December 2012. The causes of TKA failure were analyzed and compared between the groups.ResultsThirty-one revision TKAs were performed in patients ≤55 years of age at the time of primary TKA, whereas 225 cases were in those >55 years of age at primary TKA. In the ≤55 years of age group, the most common cause of TKA failure was polyethylene wear (45%) followed by infection (26%) and loosening (17%). The interval from primary TKA to revision was 8.6 years (range, 1 to 17 years). There were relatively lower infection rate and higher loosening rate in patients ≤55 years of age, but the difference was not statistically significant.ConclusionsThe main causes of failure after TKA in patients ≤55 years of age were polyethylene wear, infection and loosening, and there was no significant difference in the modes of failure after TKA between the two groups.

WhyCalculating the sample size is essential to reduce the cost of a study and to prove the hypothesis effectively.HowReferring to pilot studies and previous research studies, we can choose a proper hypothesis and simplify the studies by using a website or Microsoft Excel sheet that contains formulas for calculating sample size in the beginning stage of the study.MoreThere are numerous formulas for calculating the sample size for complicated statistics and studies, but most studies can use basic calculating methods for sample size calculation.

Autoimmune hepatitis (AIH) has been reported in association with Sjögren's syndrome (SS). Drug-induced AIH has been rarely reported. A rare case of the co-development of AIH and SS in a 53-year-old woman after the consumption of herbal medicines is described. After admission, the patient complained of dryness in her mouth, and she was subsequently diagnosed with SS, which had not been detected previously. The patient's bilirubin and aminotransferase levels initially decreased following conservative management; however, they later began to progressively increase. A diagnosis of AIH was made based on the scoring system proposed by the International Autoimmune Hepatitis Group. The patient was administered a combination of prednisolone and azathioprine, and the results of follow-up liver-function tests were found to be within the normal range. This is an unusual case of AIH and SS triggered simultaneously by the administration of herbal medicines.

An 88-year-old woman presented with abdominal pain and distension. Serum cancer antigen 125 (CA 125) level was very high; however, abdominal CT reveals ascites without definite mass. Ascites analysis revealed a lymphocytic exudate with high adenosine deaminase enzyme level, negative stains for bacteria and negative PCR for Mycobacterium tuberculosis. Presumptive diagnosis for tuberculous peritonitis was made and antituberculous therapy resulted in the resolution of ascites and normalisation of CA 125.

Despite worse trend in angiographic outcomes in the IR group (HOMA index ≥ 2.5), it was not translated into worse 1-year major clinical outcomes following PCI with DESs as compared to the non-IR group.