Thank you for allowing us to present our study comparing autograft and allograft in medial patellofemoral ligament reconstruction. I'd like to thank my co-authors. We have no disclosures relevant to this talk, but they can be found on the Academy website. As the previous presenters noted, patellar instability is common, limits athletic participation and can be very disabling. It peaks during adolescence with a rate of about 29 per 100,000. The medial patellofemoral ligament is the primary restraint to lateral patellar dislocation and as such reconstruction can prevent lateral patellar translation and dislocation. There is limited literature comparing autograft and allograft in NPFL reconstruction. On one hand, autograft is easily harvested and is readily available during the operative procedure. Cost is the time spent for harvest, but theoretically it can provide superior strength and lower re-tear rate. Allograft has less donor morbidity, but the cost is directly related to graft harvest. The purpose of the study was to compare functional outcomes and revision rate between autograft and allograft in NPFL reconstruction. Our hypothesis is that there would be no significant difference between the two. This is a retrospective chart review between the years of 2013 and 2018. The population was patients who underwent NPFL reconstruction for recurrent instability after failing in the course of non-operative treatment. We collected patient demographics, imaging variables including in-cell salivary index, patellar tilt, sulcus angle, as well as chondral injury present on MRI and we also recorded patient outcomes through phone survey as well as return to activity. The patient recorded outcomes were the same score, VIS and IKDC scores. We excluded patients with less than two years follow-up who had revision surgery or who had a concomitant tibial tubal osteotomy. Our patient demographics are listed here in table one. Most notably there was no differences in patient sex, age of the surgery, body mass index, and time from injury to surgery. Most of the injuries were due to atraumatic mechanisms. Radiographic data is represented here. Q angle, patellar height, patellar tilt, sulcus angle, and the presence of patellar chondral injury were not different between the two groups. And then for our outcome scores, follow-up duration was pretty similar between the groups. It was about four and a half years for both groups with no difference and there was no difference in SANE, VAS, IKDC, or return to activity between the groups. There was one revision surgery in the Allograft group, but this was not statistically significant. Our response rate was about 70.2%. There are a number of studies that have covered similar topics. This one from HSM in 2006 covered 34 patients, 29 Autograft, 5 Allograft with minimum two year follow-up. They also found no difference in patient-reported outcome measures and no recurrent dislocations. Subsequent study, 2009, HSM, also 20 patients, 16 Autograft, 4 Allograft, minimum two year follow-up, and no recurrent dislocations. And a recent study published out of Ohio had 115 patients, 78 Allograft, 37 Autograft, minimum one year follow-up. They had two recurrent dislocations in the Allograft group and one in the Autograft group, but no difference in patient-reported outcomes. All of these are similar to the findings in our study. The strengths of our study, we had a homogeneous cohort of patients with a response rate over 70% and minimum two year follow-up. We were limited by sample size and the retrospective nature of the study, which did not allow us to control for several variables. There were also multiple surgeons who used the various techniques for MPFL reconstruction. But in conclusion, we found there was no significant difference among patients' reported outcomes or vision rate when comparing Autograft and Allograft for MPFL reconstruction, and both remain viable options for MPFL reconstruction. Thank you.

autograft

allograft

medial patellofemoral ligament reconstruction

functional outcomes

revision rates