CORRInsights®: Does the Utilization of Allograft Tissue in Medial Patellofemoral Ligament Reconstruction in Pediatric and Adolescent Patients Restore Patellar Stability?
Recently, Weinberger and colleagues  performed a meta-analysis of observational studies comparing clinical outcomes in adult patients following MPFL reconstruction with autograft versus allograft. Although they observed greater improvement in Kujala scores among patients who received autograft reconstructions, they noted no difference in the frequency of recurrent patellofemoral instability between groups (5.7% for autograft, 6.7% for allograft) . This was evident despite the inclusion of all allograft processing techniques (including irradiation) which, if anything, would bias those results in favor of using autograft as allograft irradiation can lead to structural compromise .
With regard to ligament reconstructions in young athletes in general, it has been well documented that the use of allograft tissue for primary ACL reconstruction in young athletes is associated with an increased risk of graft rupture [3, 4, 7]. However, given the dissimilarities between the ACL and the MPFL in terms of anatomy and function, it may not be appropriate to apply findings from the ACL literature to those patients undergoing MPFL reconstruction. The ACL is a stout, intraarticular structure that provides knee stability throughout all ranges of knee flexion, and has a tensile strength of 2160 N . By contrast, the MPFL is a thin, extraarticular structure with a tensile strength of 208 N, which acts as a checkrein only in early knee flexion, until osseous patellofemoral congruity takes over at 30° of flexion [1, 5]. At present, we lack high-level comparative studies specific to the MPFL upon which we may draw meaningful data in order to council our pediatric and adolescent patients and their families regarding graft choice for MPFL reconstruction.