INCIDENCE AND RISK FACTORS FOR LOWER LIMB AMPUTATION AMONG PATIENTS IN THE SURGICAL SECTION, NATIONAL HOSPITAL OF SRI LANKA, COLOMBO A.P.G.A. Adikari, N.D.R.S. Nelundeniya, J.M.M.P. Kumari, D.M.S.M. Rathnayaka , K.A. Sriyani