Marco Lenzi

Objective. Revision total knee arthroplasty (TKA) following a periprosthetic joint infection (PJI) represents a considerable challenge. The geometry of bony defects can be hard to assess on standard x-rays, thus requiring CT evaluation. CT data can be processed to create physical replicas by 3D printing. This model can be used as means of 3D planning through surgical simulation. This study aims to compare the ability to predict the need for augmentation to restore limb alignment between 2D and 3D planning. Methods. Ten consecutive patients undergoing second-stage TKA revision following PJI were included. Pre-operative CT and standard x-rays were obtained in all patients. CT data were used to produce a model using a 3D printer. The surgical simulation was then conducted using TKA revision instrumentation. Standard 2D planning and 3D planning were independently performed by two investigators. Interclass correlation coefficient was used to evaluate agreement on the use of augment. Results. For femoral augment, 3D and 2D accuracies were 80.8 and 37.5%, respectively. For tibial augment, 3D and 2D accuracies were 66.7 and 23.0%, respectively. Conclusions. 3D planning with surgical simulation has shown to be a valuable method to predict the need of augment in revision TKA following PJI.

Summary: Background: There is increasing evidence that hepatic steatosis contributes to the progression of liver fibrosis, whereas its impact on the efficacy of anti‐viral treatment is still under investigation.Aim: To evaluate the effect of steatosis on the outcome of combined anti‐viral treatment.Methods: We studied 102 consecutive naive patients with chronic hepatitis C receiving combined anti‐viral therapy (peg‐interferonα‐2b and ribavirin).Results: Fifty (49%) of 102 patients had evidence of hepatic steatosis (29 grade 1, 16 grade 2 and 5 grade 3). Sustained virological response was similar in patients with and without steatosis (58% vs. 56%); moreover, the grade of steatosis did not affect the rate of sustained virological response (grade 1: 58%, grade 2: 56% and grade 3: 60%). Patients with steatosis had significantly higher serum levels of aspartate transaminase, alanine transaminase andγ‐glutamyltransferase (P = 0.007, 0.004 and 0.03, respectively), higher histological activity (P = 0.03), more advanced stage of fibrosis (P = 0.0394) and more often hepatitis C virus genotype 3 (P = 0.04).Conclusions: Our findings suggest that hepatic steatosis in chronic hepatitis C, irrespective of its grade, is not a negative prognostic factor of response to combined anti‐viral therapy, even when the histological and biochemical profile of the disease is more aggressive.