The goals of knee arthroplasty are to relieve pain, to provide motion while maintaining stability, and to correct deformity. According to advantages of minimally invasive surgical procedure (MIS) are to facilitate the patient’s recovery, less pain, earlier mobilization, shorter hospital stay, and quicker rehabilitation. The surgeon takes responsibility between each other and makes the decision, makes the cuts, checks accuracy of surgery even he/she uses jigs or not.

From April 2005 to February 2008, more than 50 unicompartmental knee arthroplasty (UKA) were performed at our medical center with free hand technique.

We conclude this free hand technique of MIS UKA, the small incision, short operative time, less blood loss, quick recovery, accurate alignment, and reduced fat or thrombo-embolism risk were impressed, also the extra advantage is preservation of patellar-femoral joint.