The medial patellofemoral ligament is the primary static restraint to lateral patellar translation. It is injured in 96% to 100% of patellar dislocations that affect approximately 6 to 29 of 100,000 patients and is more common in patients younger than 20 years of age. Risk factors for patellar dislocation include patella alta, trochlear dysplasia, genu valgus, increased Q angle, and hyperlaxity. The treatment for patellar instability depends on the clinical and radiographic findings and can be nonoperative for first-time dislocations (bracing, proximal strengthening, and progressive return to sport) or operative for recurrent dislocations. It is critical for medial patellofemoral ligament reconstruction to reproduce the anatomy and isometry of the native ligament. Graft choice and methods of fixation are less critical to achieve successful outcomes. Studies have reported successful outcomes and improved Kujala scores, with recurrent instability ranging from 1% to 5%. Careful surgical technique can avoid complications, including fracture, graft failure, loss of range of motion, persistent anterior knee pain, medial instability, and recurrent instability. The role of the medial quadriceps tendon femoral ligament also should be considered more in future research.
Farr J. Editorial commentary. What is the optimal management of first and recurrent patellar instability? Patellofemoral instability management continues to evolve. Arthroscopy 2018;34:3094-3097.
Fulkerson JP. Editorial commentary. Medial patellofemoral ligament reconstruction alone works well when the patient has normal alignment, but don't forget to move the tibial tubercle when necessary! Arthroscopy 2018;34:1355-1357.
Hiemstra LA, Kerslake S, Kupfer N, Lafave M. Patellofemoral stabilization: Postoperative redislocation and risk factors following surgery. Orthop J Sports Med 2019;7:2325967119852627 eCollection.
Krebs C, Tranovich M, Andrews K, Ebraheim N. The medial patellofemoral ligament: Review of the literature. J Orthop 2018;15:596-599.
Lee DY, Park YJ, Song SY, Hwang SC, Park JS, Kang DG. Which technique is better for treating patellar dislocation? A systematic review and meta-analysis. Arthroscopy 2018;34:3082-3093.
Loeb AE, Tanaka MJ. The medial patellofemoral complex. Curr Rev Musculoskelet Med 2018;11:201-208.
McNeilan RJ, Everhart JS, Mescher PK, Abouljoud M, Magnussen RA, Flanigan DC. Graft choice in isolated medial patellofemoral ligament reconstruction: A systematic review with meta-analysis of rates of recurrent instability and patient-reported outcomes for autograft, allograft, and synthetic options. Arthroscopy 2018;34:1340-1354.
Ridley TJ, Macalena JA, Arendt EA. Isolated medial patellofemoral ligament reconstruction with semitendinosus tendon allograft. JBJS Essent Surg Tech 2018;8:e5.
Schneider DK, Grawe B, Magnussen RA, et al. Outcomes after isolated medial patellofemoral ligament reconstruction for the treatment of recurrent lateral patellar dislocations: A systematic review and meta-analysis. Am J Sports Med 2016;44:2993-3005.
Shah JN, Howard JS, Flanigan DC, Brophy RH, Carey JL, Lattermann C. A systematic review of complications and failures associated with medial patellofemoral ligament reconstruction for recurrent patellar dislocation. Am J Sports Med 2012;40:1916-1923.
Sherman SL. Editorial commentary. When it comes to patient outcome, femoral tunnel vision may miss the ‘point’ in knee medial patellofemoral ligament reconstruction. Arthroscopy 2018;34:2417-419.
Smith MK, Werner BC, Diduch DR. Avoiding complications with MPFL reconstruction. Curr Rev Musculoskelet Med 2018;11:241-252.
Tanaka MJ, Voss A, Fulkerson JP. The anatomic midpoint of the attachment of the medial patellofemoral complex. J Bone Joint Surg Am 2016;98:1199-205.
Tanaka MJ, Tompkins MA, Fulkerson JP. Radiographic landmarks for the anterior attachment of the medial patellofemoral complex. Arthroscopy 2019;35:1141-1146.
Tanaka MJ, Chahla J, Farr J II, et al. Recognition of evolving medial patellofemoral anatomy provides insight for reconstruction. Knee Surg Sports Traumatol Arthrosc 2019;27:2537-2550.
- ICMJE author disclosure forms
Accepted: September 10, 2019
Received: September 10, 2019
The author reports no conflicts of interest in the authorship and publication of this article. Full ICMJE author disclosure forms are available for this article online, as supplementary material.
© 2019 by the Arthroscopy Association of North America