Cpt 27427- Medial Patellofemoral ligament, MPFL reconstruction


While researching tibia tubercle tuberosity osteotomy, MPFL reconstruction was another surgery I also learned is commonly done for patella instability.

 The MPFL ligament often becomes injured when the kneecap is dislocated. Patients with an underlying abnormality of the knee, or those with ligament laxity or weak leg muscles are at an increased risk for patella dislocations, as are individuals involved in sports or other activities that involve pivoting.

The MPFL plays an important role in keeping the patella on track and in place. It acts as a leash that restrains the movement of the patella. When patella dislocation occurs, the patella jumps the track and then comes forcibly back into place on its return. The patella bone always dislocates laterally, towards the outside part of the leg. When the patella returns into place it pulls down hard on the medial patellofemoral ligament causing ligament tearing, injury and cartilage damage.

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This procedure involves ligaments and it helps to understand what they do to get a deeper understanding of this procedure. Ligaments connect bones to other bones to form joints. They are made of soft connective tissue and have a very low blood supply compared to muscles, making them very slow to heal and recover from injury.

The medial patellofemoral ligament is a ligament that connects the patella to the femur and allows the knee to pivot and shift. It is considered an extra-articular ligament, meaning it’s on the outer aspect of the knee joint. There is another extra-articular ligament, the lateral patellofemoral ligament but I have yet to see this ligament repaired with reconstruction like I do for the mpfl. For your cpt selection you will need to select extra-articular or intra-articular, that is the key difference for the ligament reconstruction codes cpt 27427 (extra-articular) cpt 27428 (intra-articular open) and cpt 27429 (both, intra-articular and extra-articular).

Intra-articular ligaments are the anterior cruciate and posterior cruciate ligament. The medial collateral ligament and the lateral collateral ligament are also intra-articular, but they are less frequently injured and rarely require surgical reconstruction or augmentation.

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Diagnostic arthroscopy is usually done to inspect the cartilage and to see if there are any other injuries or disease processes that can be addressed during surgery.

Once the arthroscopic inspection is done, the ports are removed and the open portion of the surgery begins. The physician makes an incision over the injured ligament. The torn end may be reattached to the bone using anchors, staples, screws or washers. If reattachment on its own is not possible, the ligament is reattachment with a tendon autograft ( graft from self- think autograph) or allograft (same species, different person-cadaver ).

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Websites to learn more

Here are some good websites and a YouTube video to learn more about the procedure.

YouTube video on this procedure

Until next week,

Michelle McKinney, CPC, CCS

Cpt 27418: Tibia Tubercle Tuberosity Osteotomy-TTO Procedure


Today, I would like to write about the orthopedic knee procedure, tibia tubercle tuberosity osteotomy. The purpose of the surgery is to improve alignment of the patella. This is achieved by making a bony bridge from the tibia tubercle and moving it, with its attachment of the patella tendon more medially than its original location. A process often called by the Surgeon anteriormedialization translation (moving the patella tendon/tibia tubercle tuberosity medially on the anterior side of the knee) . Other common names for this procedure are:


The tibia tubercle is an oblong major bony ridge elevation on the tibia that provides an attachment point for the patella tendon. It acts as a lever for the patella tendon during extension and helps give the patella stability. If the patient is having patella instability, painful patella maltracking (patella is not staying in place) and symptoms of arthritis, one surgical option to correct this is tibia tubercle osteotomy (surgical cutting of a bone or a removal of a piece of bone.)


The surgery initially begins with a diagnostic arthroscopic inspection (included in the surgery, not separately charged). Visual analysis of the articular cartilage takes place to see if there is any damage or defects in the cartilage. If found,  a tool (burr, arthrocare ablation wand or shaver ) is attached to one of the scope’s. Next, debridement and shaving for clean up of the articular cartilage are done ( chondroplasty cpt 29877 can be charged if done). At the end of the arthroscopic section of the surgery, the scope is removed and the open procedure begins.

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Now, the osteotomy , the cutting of the tibia tubercle begins.

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An incision is made lateral to the patella and carried down along the distal anterior ridge of the tibia. Muscles involved in the extensor mechanism, over the anterior compartment are elevated. An incision is made through the periosteum of the tibia bone, distal to the tuberosity. K- wires are placed, a medial osteotomy is made that follows the plane of the K- wires followed by a lateral osteotomy cut. Oscillating saw and osteotome tools are used to perform these cuts. The tibial tuberosity is then repositioned in its new position. Patella tracking is assessed to check for misalignment or continued maltracking. Once proper alignment is achieved, one or more screws are drilled into the bone to secure the tibial tuberosity bony bridge in its new location.

To learn more about this procedure, check out this YouTube video on it. There are two other common patella procedures, I will blog on next.

Until next time,


Video of the procedure