Pipe fitter twisted his knee while descending stairs on job site. As a result, Employee sustained a torn right medial meniscus. Employee underwent multiple arthroscopic surgeries to repair the torn meniscus. Eventually, Employee underwent a total knee replacement of the right knee. Claim settled prior to a Hearing for permanent and total workers compensation benefits under MGL c. 152, §34A. As part of the settlement, Insurer accepted liability for Employee’s right knee meniscal tear, right knee arthroscopies, aggravation of right knee medial and patellofemoral osteoarthritis and right total knee replacement.