The SubV Knee Replacement procedure is a minimally invasive technique that leads to less pain and quicker recovery for patients with chronic severe knee pain who require joint replacement surgery. During a SubV Knee there is no cutting or disruption of the major tendons or muscles that surround the knee. The name “SubV Knee” comes from the anatomic “Subvastus approach” that is utilized to perform the procedure.
In a typical knee replacement operation the surgeon will cut through the medial aspect of the Quadriceps tendon and detach the Vastus Medialis muscle in order to gain exposure to the knee joint. The name of this technique is the Medial Parapatellar approach, and this is the way that the vast majority of knee replacement surgery is performed in the United States. At the conclusion of the case this large Medial Parapatellar cut of the tendon and muscle is sutured back together however there is obviously a significant wound in this major muscle/tendon unit that must heal over time. This can lead to increased pain in the recovery period as the muscle tries to work and is constantly pulling against the cut edge of the tendon. There can also be loss of strength early on during recovery due to the wound to the muscle and tendon. Furthermore, if the area of repaired tendon were to dehisce, or come apart, then the patella (kneecap) can become unstable and slide off the front of the knee which is extremely problematic.
In the SubV Knee (subvastus approach) there is no violation or cutting of the Quadriceps tendon or Vastus Medialis musculature. Instead of cutting through these tissues, a precision technique is utilized to go under the Vastus Medialis muscle (hence the name subvastus) which allows the surgeon to lift the muscle and slide the entire tendon/muscle complex to the side with no damage or cutting. This allows for exposure of the knee joint and the knee replacement can then be performed in a minimally invasive manner. At the conclusion of the case the muscle/tendon complex is allowed to slide back into the normal anatomic position. In this way the Quadriceps tendon and Vastus musculature are completely intact and ready to help support the knee immediately after surgery. Patients are, in most cases, able to do a straight leg raise in the recovery area and start walking within 1-2 hours of surgery. The SubV Knee is commonly performed in the outpatient setting thereby allowing patients the ability to go home the same day as surgery.
The SubV Knee is the most minimally invasive technique for performing knee replacement surgery and offers the following potential advantages over more traditional techniques:
- Less pain
- Improved strength
- Improved patellar stability
- Better early range of motion of the knee
- Same day discharge
