Minimally Invasive Knee Arthroplasty and Classic (MIS)

Shoulder arthroplasty is the replacement of a knee that has suffered chronic wear and tear, a condition known as knee osteoarthritis. It is an operation that relieves thousands of patients annually in the world and was a revolution in orthopaedics in the twentieth century. It began with hip arthroplasty and was followed by knee arthroplasty, which was first performed in 1968. Already from the 1970s to the present day, rapid progress has been made in both techniques and the quality of the materials used, to the benefit of the patient. It is estimated that around 400,000 knee arthroplasties are performed annually in the USA.

The traditional and most widely used approach is based on a large vertical skin incision in the center of the knee. In contrast, in minimally invasive total knee arthroplasty (M.I.S.), the orthopaedic surgeon uses a smaller skin incision and a less invasive technique to reduce post-operative pain and patient recovery time.
However, unlike the traditional method, the minimally invasive technique is not indicated for all patients and the treating physician must adequately expose and explain all possible surgical options.


In Minimally Invasive Total Knee Arthroplasty, although the surgery is based on the same principles as the classical method, the incision and soft tissue detachments are smaller. The artificial implants (prostheses) used are the same as those used in classical total knee arthroplasty. However, the surgical instruments used to prepare the femur and tibia are specially designed to place the prostheses correctly.
As mentioned above, Minimally Invasive Total Knee Arthroplasty uses a smaller incision of about 10 centimeters. The smaller incision results with less ditachments and injury to the patient's soft tissues. In addition to the small incision, the technique used to expose the joint is less invasive. In general, the techniques used are "quadriceps sparing", which means that they avoid injury to the quadriceps tendon and the other muscles of the anterior surface of the thigh. Other approaches or techniques may be used in Minimally Invasive Total Knee Arthroplasty.Small incisions made in the vastus medialis ("subvastus" approach), expose the joint in a less invasive way that aims to minimize injury and disorganization of the knee, which can lead to less post-operative pain and shorter recovery and rehabilitation time for the patient. The hospital stay after Minimally Invasive Total Knee Arthroplasty is typically shorter in duration than traditional knee arthroplasty surgery, ranging from one to three days. Postoperative rehabilitation is crucial for optimal outcome. The surgeon and physiotherapist assist the patient with a specific exercise program to regain strength and range of motion of the joint in a short period of time.


Minimally Invasive Total Knee Arthroplasty (M.I.S.) is a constantly evolving new technique which requires further research on long-term functional outcomes. The benefits of the minimally invasive method include less detachment and less intraoperative soft tissue injury, leading to a faster and more painless recovery. Current experience shows that the long-term benefits of the minimally invasive method are no different from those of conventional knee arthroplasty.