MPFL Reconstruction
The medial patellofemoral complex, consisting of the medial patellofemoral ligament (MPFL) and the medial patellotibial ligament, is the main passive stabilizer of the patellofemoral joint. Studies have demonstrated that MPFL rupture is the primary pathological consequence of patellar dislocation1 and that the MPFL is an important passive restraint against patellofemoral instability (PFI) and lateral patellar displacement.1 In response, MPFL reconstruction has become a widely accepted technique for restoration of patellofemoral stability, with promising clinical results.2
What Options Are Available for MPFL Reconstruction?
Three comprehensive MPFL onlay implant systems are available for patellar onlay MPFL reconstruction. All 3 kits feature hybrid Knee FiberTak® anchors for patellar graft fixation and the choice of a BioComposite FastThread™ interference screw, a FiberTag® TightRope® II PF implant, or a third hybrid Knee FiberTak anchor for femoral fixation.
Each of these kits also includes a disposable Knee FiberTak patella ratcheting guide to streamline patellar anchor implantation, as well as all sutures, drills, reamers, and guides needed for the procedure.
Why Use an Onlay MPFL Technique?
In published peer-reviewed biomechanical research, all-suture Knee FiberTak anchors have demonstrated similar time-zero cyclic elongation to interference screw fixation with stiffness and ultimate load to failure significantly greater than the native MPFL.3 Clinical peer-reviewed research has shown onlay fixation to be associated with lower complication and fracture rates than socket-based fixation, with comparable redislocation rates and PROMs.4
How Can MPFL Reconstruction Complications Be Avoided?
Because a nonanatomic MPFL reconstruction can lead to nonphysiologic patellofemoral loads and kinematics,5 the goal of surgical intervention must be an anatomic reconstruction.
Multiple studies have evaluated the femoral insertion of the MPFL. Based on these anatomic,6 biomechanical,7 and radiologic8 findings, it is now possible to avoid the complications of increased patellofemoral pressure that are associated with nonanatomic (too anterior/proximal)5 fixation of the graft. The anatomic double-bundle MPFL reconstruction technique replicates the native shape of the MPFL and maintains physiologic patellofemoral mechanics throughout flexion and extension, minimizing postoperative instability. The technique, if accomplished anatomically with direct fixation, may also provide for more aggressive rehabilitation protocols and earlier return to activity.1
An important determinant of a successful outcome of MPFL reconstruction is the proper position of the femoral fixation of the graft, and the anatomic double-bundle MPFL reconstruction technique incorporates a femoral template to ensure proper placement of the graft in the femur. This position provides a static fixation point that equalizes the tension across the graft in flexion and extension, thus minimizing the stresses across the patellofemoral joint.
References
1. Schöttle PB, Hensler D, Imhoff AB. Anatomical double-bundle MPFL reconstruction with an aperture fixation. Knee Surg Sports Traumatol Arthrosc. 2010;18(2):147-151. doi:10.1007/s00167-009-0868-z
2. Nomura E, Inoue M. Surgical technique and rationale for medial patellofemoral ligament reconstruction for recurrent patellar dislocation. Arthroscopy. 2003;19(5):E47. doi:10.1053/jars.2003.50167
3. Smith BL, Bedi A, Hauck OL, Wijdicks CA, Riboh JC. All-suture anchor onlay fixation for medial patellofemoral ligament reconstruction: a biomechanical comparison of fixation constructs. Orthop J Sports Med. 2024;12(11):23259671241294011. doi:10.1177/23259671241294011
4. Desai VS, Tagliero AJ, Parkes CW, et al. Systematic review of medial patellofemoral ligament reconstruction techniques: comparison of patellar bone socket and cortical surface fixation techniques. Arthroscopy. 2019;35(5):1618-1628. doi:10.1016/j.arthro.2018.10.150
5. Amis AA, Firer P, Mountney J, Senavongse W, Thomas NP. Anatomy and biomechanics of the medial patellofemoral ligament. Knee. 2003;10(3):215-220. doi:10.1016/ s0968-0160(03)00006-1
6. Desio SM, Burks RT, Bachus KN. Soft tissue restraints to lateral patellar translation in the human knee. Am J Sports Med. 1998;26(1):59-65. doi:10.1177/036354659802600 12701
7. Schöttle P, Schmeling A, Romero J, Weiler A. Anatomical reconstruction of the medial patellofemoral ligament using a free gracilis autograft. Arch Orthop Trauma Surg. 2009;129(3):305-309. doi:10.1007/s00402-008-0712-9
8. Schöttle PB, Schmeling A, Rosenstiel N, Weiler A. Radiographic landmarks for femoral tunnel placement in medial patellofemoral ligament reconstruction. Am J Sports Med. 2007;35(5):801-804. doi:10.1177/0363546506296415
