Subvastus Knee Replacement

Protecting and preserving muscles is one of the key factors in minimally invasive knee surgery. This is particularly true for knee joint replacement or resurfacing. The muscles help to provide strength and control to your knee. They are also an important factor in regaining motion. So, not cutting or detaching muscles around the knee results in less pain, better motion and faster recovery.

The knee joint replacement has a number of different surgical approaches. Among them, the most common knee incision is the “parapatellar” incision. This incision has the advantage of being technically easy for the surgeon as it provides good exposure to the knee. A disadvantage related to this approach is that it detaches one third of the quadriceps muscle.

The quadriceps muscle is the big muscle on the front of the thigh attached to the upper part of the kneecap. Patients with knee replacement through this approach tend to have more pain although incision in the muscle and tendon is repaired at the end of the procedure. Detachment of the muscle also results in weakness. Patients with peripatellar incisions are much less likely to be able to lift their leg the day after surgery.

Surgical approaches to the knee.

Left: peripatellar knee incision (red line); vastus medialis muscle is detached from quadriceps tendon;

Center: midvastus knee incision; vastus medialis muscle is partially split (short red line)

Right: subvastus knee incision; vastus medialis muscle is left intact.

An alternative approach is the “midvastus” approach. This is a slight improvement over the parapatellar approach; however, it still cuts into the muscle.

The subvastus approach is “quadriceps-sparing” surgical technique as the entire quadriceps muscle is left intact. Patients who have a total or partial knee replacement with the subvastus approach have less pain, better muscle control and overall faster recovery.