MRI Evaluation of Symptomatic Total Knee Arthroplasties

Abstract

IntroductionSymptomatic total knee arthroplasty (TKA) with normal studies are a challenge for the orthopedic surgeon. The nuclear magnetic resonance (MRI) could be an alternative to arrive  at a correct diagnosis.ObjectiveTo evaluate the usefulness of MRI optimized sequences in symptomatic TKA. Furthermore, conducting an interobserver study to determine which anatomical structures are evaluable.Material and methodsWe retrospectively evaluated 15 cases operated between 2007-2012 suffering periprosthetic pain, with normal radiographs, negative scintigraphy and normal laboratory undergoing MRI.An interobserver analysis using interclass correlation coefficient (ICC) and Kappa between 4 professionals, a resident of diagnostic imaging and an advanced Orthopedic resident, and 2 doctors with 20 years of experience, one in diagnostic imaging and the other in  knee surgery.ResultsJoint fluid was increased in 14 patients; synovitis in 4; an infra patellar ossicle but osteolysis was not found in any of the patients. In 7 cases the collateral ligaments could be evaluated properly. The gastrocnemius, the subcutaneous tissue and the extensor apparatus were evaluated without difficulty. MRI found causes of pain in 12 cases. The ICC showed concordance for the medial collateral ligament, the extensor apparatus, twins and subcutaneous tissue.Conclusion Our study demonstrates the utility of the method in decision-making. The interobserver agreement was statistically significant for the analysis of the medial collateral ligament, gastrocnemius and subcutaneous tissue.