Kneecap (Patellar) Instability: Ligament Reconstruction Using Soft Anchors and Screws Animation

Kneecap (Patellar) Instability: Ligament Reconstruction Using Soft Anchors and Screws Animation

This animation demonstrates a medial patellofemoral ligament, or MPFL, reconstruction using a tendon graft, soft-body anchors, and an absorbable screw. The MPFL is located on the inner side of the knee and connects the kneecap to the thigh bone, or femur, playing a key role in stabilizing the kneecap and preventing it from slipping out of position.

A small incision is made along the inner border of the kneecap, and the bone is prepared for graft fixation. A drill guide is positioned on the kneecap, and a socket is created using a drill. A soft-body anchor is then inserted into the socket and tapped into place. As the drill guide is removed, sutures attached to the anchor are released. Each anchor contains black and blue suture tapes, and tension is applied to the black sutures to secure the anchor beneath the bone. These steps are repeated for a second anchor.

The tendon graft is then positioned through the loops of the blue sutures, and tension is applied to secure the graft along the inner border of the kneecap. Attention is turned to the thigh bone, where a template and x-ray guidance are used to precisely identify the MPFL attachment site. Once confirmed, a guide pin is drilled through the femur to create a tunnel, and a reamer is used to form a socket at the tunnel entrance.

A passing suture is routed beneath the skin and attached to the graft ends to guide the graft through the femoral tunnel. Once proper kneecap alignment and graft tension are achieved, an absorbable screw is inserted into the femoral socket to secure the graft. The black suture tapes are then used to close the soft tissue around the kneecap, and additional sutures are placed to close the skin incisions, completing the procedure.