Expert‐based studies benefit from formal consensus methodology and balanced expert representation: Reconsidering the role of primary ACL repair

Anterior cruciate ligament (ACL) injury management continues to evolve, with ACL reconstruction (ACLR) considered the standard of care. However, renewed interest in primary ACL repair has emerged as an alternative treatment method, supported by a growing body of evidence. The recent survey results by Konstantinou et al. [16] at the 2024 Freddie Fu Panther Sports Medicine Symposium provided valuable insight into current attitudes toward ACL repair, highlighting its limited uptake among orthopaedic surgeons attending the symposium. In this expert study, three cases were discussed: a 17-year-old competitive soccer player and two physically active patients in their 50s [16]. While this expert survey is a valuable snapshot, several nuances merit consideration to contextualize the findings and strengthen their interpretation. Although consensus-building expert meetings are crucial in shaping clinical practice, their validity is heavily dependent on methodology and representation. Consensus, in this context, refers to an agreement reached through a rigorous and transparent methodology that integrates pluralistic expert input, follows an iterative process with independent steering and rating groups, and is supported by a comprehensive literature review [2, 3, 11]. In contrast to a formal consensus process, the study by Konstantinou et al. [16] employed a single-round survey conducted during a plenary symposium. The results should therefore be interpreted as an expert opinion with a low level of evidence (Level 5), as survey responses obtained during a plenary symposium setting are susceptible to conformity bias, where group dynamics could influence individual responses. Nevertheless, the authors repeatedly use the term “consensus” throughout their article and conclusion, which may lead readers to overestimate the methodological rigour. Notably, the prespecified ‘consensus’ threshold (≥80%) appears to have been rarely met, indicating that little true agreement emerged beyond the recognized role of ACLR in young athletes. In addition, the authors describe their participants as a ‘global consortium of clinical and research experts’ on ACL biology, injury, and treatment/rehabilitation, yet provide no details on the respondents' specific backgrounds. As a result, the clinical or research experience with ACL repair within this global consortium is unclear. Consequently, the survey findings may have been skewed toward the opinions of reconstruction-focused surgeons, rather than presenting a balanced perspective. A more balanced representation explicitly including surgeons with established clinical and research experience in primary repair would further strengthen the panel's external validity. Alternatively, an unbiased review of recent literature on ACL repair, reconstruction, and conservative therapy preceding the survey would have allowed the respondents to evaluate the scenarios using current scientific evidence rather than relying primarily on personal experience. By presenting only three cases—a 17-year-old competitive soccer player and two patients in their 50s—the survey oversimplifies the complexity of ACL pathology, as the largest group undergoing ACL surgery, patients in their 20s and 30s, is not represented [1, 20, 24]. Therefore, we believe the title may overstate the results. When treating ACL injuries, the clinical decision-making is typically driven by age and activity level, which is also the case for the consideration of ACL repair. As several studies have shown failure rates of up to 40% following ACL repair, in select groups of younger patients [27], several ACL repair experts have cautioned against isolated ACL repair in young patients [8, 12, 22, 25]. Therefore, it is unsurprising that, during the 2024 Freddie Fu Panther Sports Medicine Symposium, ACLR was preferred by 91% of surgeons for the presented case of a 17-year-old competitive soccer player with a proximal tear [16]. As we agree with the preference of ACLR in this case, ACLR cannot be considered a ‘safe haven’. Even with modern reconstructive techniques, failure rates remain high in this high-risk population [9, 28]. In the STABILITY trial, 40% of patients in the standard ACLR group sustained a clinical ACL failure (persistent laxity or graft rupture) within 2 years, and 25% in the ACLR with lateral extra-articular tenodesis group [9]. Early data suggest that, analogous to ACLR, anterolateral augmentation may reduce failure after ACL repair, although the level of evidence is currently lower than for ACLR [5, 15]. It is also important to note that reported failure rates strongly depend on the chosen definition, which may range from revision surgery alone, to structural laxity or discontinuity, to broader clinical failure, including subjective instability. In summary, attributing high failure rates solely to ACL repair ignores the major role of age and/or activity level, which drive failures across all treatments. The decision-making for the two patients in their 50s with a proximal avulsion tear is considerably more nuanced than suggested by the survey results, where the majority of experts (61%) at the 2024 Freddie Fu Panther Sports Medicine Symposium favoured ACLR [16]. First, when reviewing failure rates of ACL repair in older patients, the outcomes between ACL repair and ACLR are not dissimilar. Rilk et al. [22] showed in their meta-analysis that patients over 21 years of age had similarly low failure rates following ACL repair (2.3%) and ACLR (0.8%), and a previous study similarly showed a failure rate of 3.2% in patients over 35 years [27]. Second, prospectively collected comparative data—including randomized trials of BEAR and DIS as well as matched prospective cohorts—consistently show no clinically important differences between repair and reconstruction in selected adults [4, 5, 10, 13, 14, 17-19, 26]. This is supported by recent systematic reviews with meta-analyses that stratify by study design and age, and consistently conclude that outcomes are similar between ACL repair and ACLR in adults [22, 25]. Third, beyond the importance of failure rate, patient-reported outcome measures need to be considered. Three separate studies have shown significantly higher forgotten joint scores in ACL repair compared to ACLR, with values approaching those of healthy uninjured knees, an outcome not observed after ACLR [4, 5, 26]. Finally, RCTs such as the KANON and COMPARE trial, comparing immediate ACLR with a conservative-first approach, support a conservative-first approach [6, 7, 21]. Nevertheless, the majority of experts (61%) at the 2024 Freddie Fu Panther Sports Medicine Symposium would opt for immediate reconstruction in these older patients [16]. Notably, there are at least as many randomized trials directly comparing repair versus ACLR [13, 17, 19] as there are trials comparing ACLR versus initial conservative management of acute ACL injury (albeit with fewer total included patients) [6, 7, 21], yet immediate ACLR remains widely adopted even outside the youngest cohort [16]. This discrepancy with the available literature supports our initial concern that the consortium may not present a balanced perspective toward ACL treatment. We agree with Konstantinou et al. [16] that ACLR is the standard of care and the preferred treatment for young and highly active patients. ACL repair should not be considered a replacement for the standard of care, but a valuable asset in the surgeon's armamentarium [23], as supported by a growing body of comparative evidence [4, 10, 14, 17, 18]. In parallel, future expert-based work would benefit from formal consensus methodology, balanced expert representation (including repair specialists) and explicit endpoint definitions (revision, structural failure and clinical failure) to facilitate fair interpretation across treatments. All authors contributed substantially to this work. Initial manuscript drafting was performed by Jasper Vandenrijt, Christiaan Hendrik Willem Heusdens and Jelle Philip van der List. The draft manuscript was thoroughly revised by all authors, and the final version was read and approved by all authors. Roy Antonius Gerhardus Hoogeslag is a member of the editorial board of KSSTA and serves as an educational consultant for Arthrex. Clemens Kösters serves as a medical advisor for Enovis. Etienne Cavaignac serves as a consultant for Arthrex and for Smith & Nephew. Edoardo Monaco is also a consultant for Arthrex. The remaining authors declare no conflicts of interest. This is a commentary paper that requires no ethical approval. Data Availability Statement is not available.