Autograft and Allograft Anterior Cruciate Ligament Reconstruction in Patients Older Than 40 Years Have Similar Short-Term Patient-Reported Outcomes With Greater Rates of Anterior Cruciate Ligament Graft Failure in Patients Who Receive Allograft

Abstract

PurposeThe purpose of this study was to evaluate short-term patient-reported outcomes (PROs) in patients aged 40 and older after primary ACLR between patients that received allograft or autograft. Secondary aims included assessing the effect of pre-existing osteoarthritis on short-term PROs. MethodsA retrospective review of an ambulatory surgery center’s electronic medical record was conducted for patients who underwent primary ACLR between 2009 and 2022. Patients aged younger than 40, those who underwent index revision procedures and/or concomitant ligament repair/reconstructions, and those with incomplete baseline or short-term (1- or 2-year) KOOS scores were excluded. Allograft and autograft patients were matched according to sex and body mass index (BMI) in a 2:1 fashion. PROs used included KOOS and Single Assessment Numeric Evaluation (SANE) at baseline and short-term follow up (minimum of 1 year). Minimum clinically important difference was calculated in a distribution-based fashion. Osteoarthritis severity was determined based on Kellgren-Lawrence grading of perioperative knee x-rays. Preexisting osteoarthritis was defined as KL grade 1 or more. ResultsA total of 331 patients were included after matching (215 allograft and 116 autograft patients). The average age was 47.7 ± 6.0 (range: 40-66). Age differed significantly between the two groups, with the allograft cohort having an average age of 48.6 ± 6.0 years and the autograft cohort having an average age of 46.1 ± 5.7 years (p < 0.001). Short-term change in KOOS and SANE scores did not differ by graft type (p = 0.154, p = 0.556, respectively). Sixty-seven percent of all patients met MCID for KOOS and 82% of patients with complete baseline and short-term SANE scores met MCID for SANE. There was a statistically significant difference in rupture rates between the allograft and autograft cohorts (n = 9 allograft vs n = 0 autograft; p = 0.030). There was no difference in re-operation rates between the autograft and allograft cohorts (p = 0.453). Perioperative Kellgren-Lawrence grading did not affect outcomes for either graft type (allograft: p = 0.905 vs. autograft: p = 0.522). ConclusionMiddle-aged patients undergoing ACLR with allograft or autograft demonstrate similar short-term patient reported outcomes. Pre-existing osteoarthritis similarly did not significantly affect short-term outcomes. However, rerupture rates were significantly higher in the allograft cohort than the autograft cohort. Level of EvidenceLevel III - Therapeutic