In the three years' period 1976-1978, 53 GSB knee prostheses were inserted in 46 patients. The use of this type of prosthesis was mainly indicated for the relief of pain in the presence of severe deformity or ligamentous insufficiency. There were two subsequent arthrodeses, one for infection and one for persistent pain. A follow-up study of 39 prostheses (excluding the two arthrodeses) revealed relief or reduction of pain to an acceptable level in 35 of the 39 knees (90%). The patients, however, were enthusiastic or satisfied with 37 of the 39 knee prostheses available for follow-up (05%). Good alignment and movement were obtained in all knees except one, in which flexion was less than 60 degrees. The most frequent problem was mild to moderate patello-femoral pain in 12 (31%) of the 39 knee-arthroplasties. This can largely be avoided if taken into account when planning the operation.