Poster 342: Anterior Cruciate Ligament Reconstruction in Recreational Athletes Aged 40 and Older: Activity Level as an Indication
Authors: Huyke-Hernandez Fernando , Only Arthur , Kweon Christopher , Cunningham Brian , Doxey Stephen 
Published: August 2023

Objectives: The number of patients that are continuing to be active is extending into middle age. Many in this population report consistent participation in recreational sports. Anterior cruciate ligament reconstruction (ACLR) is the gold standard for treatment among young athletic patients, but nonoperative treatment has historically been utilized more often in older patient populations. It has been traditionally thought that older adult patients do not share the same activity level as younger patients and thus are not in need of surgical treatment of an ACL injury. There is some hesitancy to treat older patients if they have mild to moderate pre-existing arthritis, but in recent years the literature has demonstrated good outcomes in this population. The type of graft used in older patients is another source of controversy, with many surgeons opting to use allograft rather than a patient’s native tissue for ACLR. Factors that can inform decision-making such as pre-injury activity level and employment have not been thoroughly assessed for these patients. The purpose of this study was to better understand indications for ACLR in patients aged 40 and older by characterizing their activity level, mechanisms of injury, employment status, demographics, surgical characteristics, and patient reported outcomes (PROs). Methods: A registry of prospectively-collected PROs from a single metropolitan ambulatory surgical center was retrospectively reviewed for patients that received an ACLR from 2009-2016. Patients younger than 40 years old, revision procedures, and concomitant ligament repairs or reconstructions were excluded. Demographic, employment, activity, injury, and surgical characteristics were extracted via chart review. The level of strength required by the patient’s occupation was stratified by the definitions from the United States Department of Labor Occupation Requirements Survey (graded as “sedentary”, “light work”, “medium work”, “heavy work”, “very heavy work”). Surgical outcomes include ACLR failure or re-rupture, ipsilateral knee re-operations, and complications. PROs utilized were the Single Assessment Numeric Evaluation (SANE) and Knee Injury & Osteoarthritis Outcome Score (KOOS) collected pre-operatively and at two years post-operatively. Results: A total of 141 patients were identified. More than half the patients were female (n=81, 58%) and the average age was 47 years old (range: 40-66). Approximately 87% (n=124) of patients had PRO data. The average KOOS and SANE at two-year follow-up were 80.0 ± 15.9 and 85.3 ± 22.0, respectively. The average change from baseline score were 20.8 ± 20.2 and 24.1 ± 30.3 for KOOS and SANE, respectively. Pre-existing arthritis was found in the majority of patients (n=88, 62%). The most common graft type used for ACLR in this group was allograft (n=95, 67%). Injured menisci were typically treated with meniscectomy vs repair (n=65, 56%). The majority of patients (n=104, 77%) were engaged in a sport when they sustained an ACL injury, with 96% being engaged in a sport that requires running, jumping, and other high-impact activity. Those injured while involved in a sport on average demonstrated higher KOOS scores at baseline and at two-year follow up compared to those that were not involved in a sport (61.5 ± 18.0 vs 51.6 ± 18.0 at baseline, p=0.045; 82.8 ± 13.7 vs 70.8 ± 19.5 at two years, p=0.0048). A total of 27 of the sporting-related injuries occurred in patients age 50 or older (60% of n=45 patients age 50 years or older). All of these patients expressed a desire to return to sport and pre-injury activity. Skiing was the most frequently cited sport (n=41, 29%). Most ACL injuries were acute, with just 10% found to be chronic. The mechanism of injury varied by activity, but non-contact type ACL injuries were the most prevalent (n=66, 49%). Although most patients worked in a sedentary or desk job environment (n=87, 65%), some worked in very heavy-duty jobs (n=18, 14%). There was a low incidence of re-ruptures and re-operations (4.5% and 8.7%, respectively). Conclusions: The majority of patients aged 40 and over sustained ACL injuries while engaging in sports, with all of these patients citing a desire to return to sport and pre-injury activity level as their reason for wanting an ACLR. Patients were mostly treated with allograft compared to autograft, and meniscal injuries were most frequently treated through meniscectomy instead of repair. Many of these patients had some form of pre-existing arthritis and still went on to have surgery with excellent outcomes. PROs were also found to be higher initially and at two-year follow-up in the more active adult group, suggesting that pre-injury and post-injury activity level is associated with improved outcomes. When an older adult patient presents with an ACL tear, surgeons should consider the activity level and desires of the patient as they determine the appropriate avenue of treatment. There is certainly a role for conducting ACLR in patients aged 40 or older. [Table: see text][Table: see text][Table: see text]