Knee Arthritis: Tibial Opening Wedge Osteotomy

Knee Arthritis: Tibial Opening Wedge Osteotomy

This surgical demonstration on a left cadaver knee shows a tibial opening wedge osteotomy for the treatment of knee arthritis. This surgery is typically reserved for younger patients with poor alignment of their leg that results in early cartilage damage. By realigning the leg with an osteotomy, or cutting of the bone, pressure is relieved on the damaged cartilage to help prevent it from getting worse. This surgery is commonly done with some type of cartilage repair or ligament reconstruction procedure.

Here we have a left knee. The surgeon will start by marking out specific locations on the skin to perform the surgery. The incision is made on the inside of the knee over the front of the shinbone. The surgeon then goes through a series of steps to move the different soft tissues out of the way to get all the way down to the bone.

Next, the surgeon uses a large guide and lines it up on the knee. X-ray is used in the operating room to make sure the guide is in the right spot. Two small pins are then inserted through the guide to hold it in place. A larger hole is drilled towards the outside of the knee and a longer, larger pin is inserted. This is the hinge point that will allow the bone to be shifted and put back in alignment.

The plastic portions of the guide are removed and only the metal part is left behind. Two large holes are then drilled on the inside of the knee. This part of the guide is swapped out, and this slot here is for the saw blade to make the final bone cut. Before the cut is made, the surgeon will place a protective hook around the back of the knee to help protect the soft tissue.

Next, using the saw, the surgeon cuts the bone up until the hinge point, leaving a small area of bone intact on the outside of the knee. After the bone is cut, all the guides are removed. Then, this opening device is used to open the gap and realign the bone. It is important to measure the opening to make sure the bone is shifted the right amount.

After that, the surgeon may choose to insert synthetic bone wedges to fill the gap. Next, a rigid implant is placed to keep the gap open, fitting into the 2 previously drilled holes. Four anchors are then placed into the 4 holes in the implant, securing it into the bone. The surgeon can then choose to use any number of other synthetic or biologic products to fill the rest of the gap from the bone cut.

Once this is done, the soft tissue is repaired back in place and the incision is closed with sutures.