Opinions differ on unicompartmental knee replacement for treatment of unicompartmental ostearthritis of the knee. There is general agreement that well-functioning cruciate ligaments are necessary if use of this prosthesis is to be successful. Especially for younger people who are still working and who have advanced medial arthritis and lacking or inadequate anterior cruciate ligament, this therapy has its limitations. To exploit the advantages of unicondylar replacement in such patients, we combined this joint replacement operation with reconstruction of the anterior cruciate ligament using the semitendinosus/gracilis tendon and applying a transfix technique in 7 cases. The mean Knee Society Score was recorded preoperatively and after 12 and 28 months of follow-up. Long-term results are not yet available, but after this operation method average Knee Society Scores of 164.1 were recorded at 28 months, and all these patients were able to return to work after their rehabilitation. Thus, the short-term follow-up documents the efficacity of the treatment and benefit to the patients.