Medial Patellofemoral Ligament Reconstruction Using Dual Patella Docking Technique

Abstract

Medial patellofemoral ligament (MPFL) injuries are common in children and young adults. In patients with recurrent patellar dislocations with normal lower-extremity alignment, anatomic reconstruction of the MPFL has been shown to restore patellar stability. We describe a technique that creates an anatomic reconstruction using a dual docking technique into the patella. Our technique is simple and efficacious for reconstructing the MPFL without implant fixation in the patella, allowing a maximal bone-tendon interface for healing.

Fig 1

Graft preparation using Acufex tensioning device (Smith & Nephew). To the left is the single arm that will be inserted into the distal femur; to the right are the 2 arms that will be inserted into the patella.

Fig 2

(A) Lateral radiograph of a knee with anterior to the left and posterior to the right with the pin at our femoral tunnel location, anterior to the posterior cortical line (asterisk) and superior to the Blumensaat line (arrow). (B) Clinical photograph of a left knee in a patient positioned supine with the Beath pin entering through a medial incision, drilled into the femoral tunnel starting location.

Fig 3

Photograph of a left knee in a patient positioned supine with proximal to the left and distal to the right. The semitendinosus graft (arrow) is being secured into the medial femoral tunnel. The guidewire (asterisk) for an interference screw is in place.

Fig 4

Photograph of a left knee in a patient positioned supine with proximal to the left and distal to the right. One limb of the semitendinosus graft (arrow) is being shuttled through the medial knee retinacular tunnel, exiting adjacent to the patella. The second limb (asterisk) has not yet been shuttled.

Fig 5

(A) Photograph of a left knee in a patient positioned supine with proximal to the left and distal to the right. The medial aspect of the patella with the 2 tunnel sites is marked (arrows). Two Beath pins are drilled through the patella at these sites. (B) Lateral fluoroscopic image of a left knee after the Beath pins (arrows) have been drilled from medial to lateral across the patella. The image confirms that the pins remain extra-articular as they cross the patella.

Fig 6

Photograph of a left knee in a patient positioned supine with proximal to the left and distal to the right. We prepare to drill our tunnel with a 4.0-mm cannulated reamer (asterisk). The reamer has been marked at 2 cm (arrow). We visually confirm that the spacing is adequate such that the tunnels do not meet.

Fig 7

Photographs of a left knee in a patient positioned supine with proximal to the left and distal to the right. (A) Measurement of graft limbs. We mark the graft 2 cm distal (arrowhead) to the point at which it makes contact with the medial cortex of the patella (arrow). (B) Suturing of grafts with a straight needle (asterisk) and a looped FiberWire suture from the point of contact with the medial cortex of the patella (arrow) to the marked point 2 cm distal (arrowhead).

Fig 8

(A) Photograph of a left knee in a patient positioned supine with proximal at the top and distal at the bottom. Both graft limbs have been secured into their respective patellar tunnels (asterisks) on the medial aspect of the patella. (B) Sutures coming out of the lateral incision after they have been passed through the patella from medial to lateral. The sutures from the different graft limbs are tied to each other.