Minimally invasive surgery of the knee.

Minimally invasive knee replacement surgery has been developed in an attempt to lessen the impact of operations on the patient's quality of life, in the same way as arthroscopy, the forefather of minimally invasive surgery (MIS), revolutionised cartilage and ligament surgery three decades earlier. The technique is based on minimising soft tissue and muscle trauma, skin incision length, and capsular disruption while trying to maintain the ultimate goal of a well-aligned, well-fixed knee replacement. Short-term advantages including accelerated recovery and reduction in blood loss have been demonstrated, but it remains to be investigated whether MIS is able to provide sustainable benefits and long-term outcome equivalent to conventional surgery. Successful application of MIS techniques have been confirmed in conjunction with unicompartmental knee arthroplasty (UKR) implantation, while its use with total knee arthroplasty remains experimental. Critics have expressed concern that reduced visibility may compromise implant positioning and leg alignment which could have a negative effect on prosthetic long-term survival. MIS clearly represents a unique and more technically demanding procedure, but the learning curve may perhaps overshadow the benefits. Computer navigation may help to avoid such problems but so far scientific evidence regarding definitive outcomes is lacking, and some of the MIS techniques are still in the early phases of development.