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

Purpose: To evaluate short-term patient-reported outcomes (PROs) in patients aged 40 years and older after primary anterior cruciate ligament reconstruction (ACLR) between patients who received allograft or autograft. Secondary aims included assessing the effect of preexisting osteoarthritis on short-term PROs.

Methods: A 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 years, those who underwent index revision procedures and/or concomitant ligament repair/reconstructions, and those with incomplete baseline or short-term (1- or 2-year) Knee Injury and Osteoarthritis Outcomes Score (KOOS) scores were excluded. Patients who received allograft or autograft were matched according to sex and body mass index 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 on the basis of Kellgren-Lawrence (KL) grading of perioperative knee radiographs. Preexisting osteoarthritis was defined as KL grade 1 or more.

Results: A total of 331 patients were included after matching (215 allograft and 116 autograft patients). The average age was 47.7 ± 6.0 years (range 40-66 years). Age differed significantly between the 2 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 < .001). Short-term change in KOOS and SANE scores did not differ by graft type (P = .154, P = .556, respectively). Sixty-seven percent of all patients met minimum clinically important difference for KOOS and 82% of patients with complete baseline and short-term SANE scores met minimum clinically important difference 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 = .030). There was no difference in reoperation rates between the autograft and allograft cohorts (P = .453). Perioperative KL grading did not affect outcomes for either graft type (allograft: P = .905 vs autograft: P = .522).

Conclusions: Middle-aged patients undergoing ACLR with allograft or autograft demonstrate similar short-term PROs. Preexisting osteoarthritis similarly did not significantly affect short-term outcomes. However, rerupture rates were significantly greater in the allograft cohort than the autograft cohort.

Level of evidence: Level III, therapeutic, retrospective, case control study.