Considerations in revision of anterior cruciate ligament reconstruction in the high-level athlete

Introduction

Anterior cruciate ligament reconstruction (ACLR) is a widely performed procedure aimed at restoring knee stability and function following an anterior cruciate ligament (ACL) rupture. One of the major concerns and risks of ACLR is ACL graft failure. Although ACLR is generally a successful operation, rates of ACL graft failure remain a prominent concern. Literature reviews estimate that revision ACLR is required in 6.5–34% of cases (1). Consequences of ACL graft failure include reduced athletic performance and an increased risk for the development of osteoarthritis (2). Studies have shown that athletes who have undergone ACLR have up to 15 times greater risk of suffering a second ACL injury compared to uninjured individuals (3). Recognizing and addressing the causes of ACL graft failure in the revision setting is critical for optimizing graft success and a safe return to sport (RTS) (4).

The causes of ACL graft failure are multifactorial, with a combination of biomechanical, surgical, and biological factors. Previous literature has shown that technical error is the most common cause for ACL graft failure (5). More recently the Multicenter ACL Revision Study (MARS) found that the most common causes of failure were isolated traumatic injuries followed by isolated technical errors (6). A cross-sectional study conducted by the MARS group in 2010 found that within technical errors, femoral tunnel malposition was classified as the most common cause of failure, with tibial tunnel malposition being second (7).

As ACLR continues to grow, so do the rates of ACL graft failure. Such outcomes can be avoided by improving surgical techniques, refining patient selection, and implementing evidence-based rehabilitation protocols. This is especially important in high-level athlete, as their future success in sport may be compromised if they experience ACL graft failure following ACLR. The purpose of this review is to discuss considerations in revision ACLR with a focus on the high-level athlete. When we are faced with these situations, it is imperative to have an approach to revision ACLR to maximize the athlete’s future success in sport and overall health of their knee.

Methods

This review employs a comprehensive literature review to synthesize current evidence on the management of revision ACLR in the high-level athlete. A structured search of PubMed, MEDLINE, and Google Scholar was conducted using keywords such as “revision ACL reconstruction”, “athlete”, “high-level athlete”, “elite-athlete”, and “return to sport”. The review focused on studies published in the last 30 years that examined outcomes and considerations in revision ACLR, while including considerations in high-level athletes and RTS outcomes when available. The selection prioritized studies evaluating treatment efficacy, failure rates, and return-to-play outcomes. Literature was included that explored graft selection, ACL tunnel position, concomitant injuries, augmentation with anterolateral procedures, augmentation with osteotomy, and staging reconstructions. Data were extracted systematically, and a qualitative synthesis was conducted to identify trends, consensus guidelines, and differences in management. Special attention was given to management considerations and RTS in the high-level athlete, ensuring an evidence-based review to guide clinicians in selecting the appropriate treatment plan.

Discussion

Clinical evaluation

Evaluation of the athlete in the setting of ACL graft failure must be thorough and include a focused history and physical examination, imaging analysis (both prior to initial reconstruction and new imaging), and review of the operative notes.

In elucidating an appropriate history, the physician should assess whether they were able to RTS after their prior ACLR. Was their previous ACLR rehabilitation successful—did they have a stable, painless knee, and were they able to return at the same level? If they were unable to RTS and were experiencing continuous knee instability without a new traumatic event, this may point to an early ACL graft failure. If they were able to RTS and experienced a new traumatic event, history should focus on the mechanism of the trauma, whether they experienced a pop or effusion, and timing of the season in which this occurred. The physician should also discuss level of sport in which they play, type of sport, and expectations of the patient in terms of RTS. Timing during the season is especially important, as this information can inform your discussion surrounding timing of surgery and RTS the following season.

A focused physical examination of the affected knee and contralateral knee should be performed. This should include examination of standing alignment, effusion present, range of motion (ROM), testing of Lachman and anterior drawer, pivot shift, joint line tenderness, McMurray test, posterior drawer/posterior sag/quadriceps active, dial test, stability to varus and valgus stress at 0 and 30 degrees of knee flexion, and a neurovascular examination. Hyperlaxity should also be assessed through a Beighton score with a particular focus on knee hyperextension.

Standard radiographs of the knee should be obtained, including standing anteroposterior (AP), standing lateral, 45-degree posteroanterior (PA) flexion views, merchant views, and a four-foot standing radiograph to assess coronal alignment. In these studies, assessment can be carried out regarding tunnel position, posterior tibial slope (PTS), anterior tibial translation (ATT), progression of osteoarthritis, and overall alignment. For assessment of the PTS and ATT, it is important to get standing lateral radiographs at 30 degrees of knee flexion (8). If there is suspicion of ACL graft failure, a magnetic resonance imaging (MRI) should be obtained to assess the cruciate ligaments, assess the status of the meniscus, cartilage, and collateral ligaments. A computed tomography (CT) scan with three-dimensional (3D) reformatting should be obtained to assess tunnel position and tunnel lysis accurately. Prior physician notes (both clinical and operative) and imaging (radiographs and MRI) should be obtained to review graft used, whether other meniscus or collateral ligament injury was addressed, and if injury to the meniscus, collaterals, or cartilage was present but not addressed during the initial surgery.

Obtaining an appropriate history, physical examination, imaging, and prior operative and other clinical notes will help in determining the best course of future treatment in the setting of ACL graft failure in the high-level athlete. Once all of this information is gathered, considerations in treatment can be analyzed.

Considerations in planning for revision ACL reconstruction

When planning for revision ACLR, one must consider the following. (I) Are the previous ACL tunnels placed in the anatomic position? (II) What graft was used in the initial ACLR, and which should be used during revision ACLR? (III) Were any concomitant injuries missed during the index procedure? (IV) Are there tibial slope abnormalities that must be addressed? (V) Can we safely perform a single-stage procedure, or will the procedure be more successful in two stages? (VI) Should the revision be augmented with a lateral extraarticular procedure? In this review, we will cover all these considerations in the high-level athlete with a first-time ACL graft failure.

Tunnel position

The most common technical cause of ACL graft failure is tunnel malposition, accounting for up to 60% of ACL graft failures as cited by the MARS group (9). In the MARS cohort, femoral tunnel malposition was the most common technical error, requiring drilling of an entirely new femoral tunnel in 82% of revision ACLR cases (9). Most commonly, the femoral tunnel was placed too vertically during the index procedure, followed by too anterior (9). Nonanatomic tunnel position may be due to a technical error but may also be due to choice of technique by the index surgeon. A recent systematic review found that non-anatomic femoral tunnel placement occurred more commonly in transtibial techniques versus anteromedial portal drilling, with increased ACL graft failure rates following transtibial drilling (10).

As nonanatomic tunnel placement is the most common technical cause of ACL graft failure, one must critically assess tunnel position in these patients to mitigate risk of ACL graft failure following revision ACLR. When assessing femoral tunnel placement, we prefer the quadrant method as described by Bernard et al. (1997) on lateral knee radiographs (11) (Figure 1). In this method, the total sagittal diameter of the lateral femoral condyle is divided into four quadrants along Blumensaat line, and the intercondylar notch height is divided into four quadrants. The femoral tunnel is deemed anatomic when it is located in the most posterosuperior quadrant of this grid. When critically assessing tibial tunnel placement, the tibial plateau is divided into four quadrants on a lateral knee radiograph, with the anatomic position being in the posterior third of the second quadrant (12). The anatomic position can also be determined as 43% from anterior to posterior on a lateral knee radiograph (13). In addition to tibial and femoral tunnel location, tunnel obliquity or verticality of the femoral tunnel should be assessed. On 45-degree flexion weight-bearing PA knee radiographs, a femoral tunnel obliquity of less than 32.7 degrees indicates non-anatomic placement, or a tunnel that is “too vertical” (14) (Figure 2).

Figure 1 Lateral radiograph of the right knee. Femoral tunnel placement is determined by dividing the Blumensaat line and the maximum intercondylar notch height into 4 equal quadrants each, with appropriate anatomic tunnel placement (yellow circle) in the most posterosuperior quadrant.

Figure 2 45° PA flexion weight-bearing views of a patient with prior ACLR. Femoral tunnel obliquity can be measured by determining the axis of the femoral shaft and creating an angle with the direction of the femoral tunnel. An angle greater than 32.7° is consistent with anatomic tunnel placement. ACLR, anterior cruciate ligament reconstruction; PA, posteroanterior.

In terms of advanced imaging in assessing tunnel placement, 3D CT imaging is considered the gold standard, and we advocate for this in all our patients (15) (Figure 3). CT scan will not only allow the surgeon to assess tunnel position but also tunnel lysis, measured as the widest point on coronal, axial, and sagittal planes. Tunnel lysis of 15 mm or greater is considered significant and should lead the surgeon to consider a two-stage procedure with bone grafting of the ACL tunnels in the first stage (16). Recommending a two-stage procedure can be increasingly difficult in the setting of the high-level athlete. The discussion should be patient-centered and involve setting expectations early regarding an extended timeframe for RTS.

Figure 3 3D CT reconstruction of the knee, which can be used to determine the position of previous tunnels (blue star indicates femoral tunnel placement). 3D CT, three-dimensional computed tomography.

Graft choice

The most important considerations in graft choice during revision ACLR are prior ACLR graft and patient age or activity level (17). Options for graft choice include autograft, either from the ipsilateral or contralateral lower extremity, depending on previous graft use [bone-patellar tendon-bone (BPTB), quadriceps tendon (QT), and hamstring tendon (HT)], as well as allograft.

Allograft is a common choice in revision ACLR, being 3.6 times more likely to be chosen compared to autograft (17). There seems to be contrast in the literature surrounding ACL graft failure rates when comparing allograft and autograft in revision ACLR. A recent meta-analysis on revision ACLR concluded that the ACL graft failure rate was similar between autograft (4.1%) and allograft (3.6%) among 8 studies (18). In this meta-analysis, only two studies included the ACL graft failure rate of allograft, while eight studies included the ACL graft failure rate of autograft at a minimum of two years. Another recent meta-analysis of 32 studies conversely concluded that following revision ACLR, autografts performed better than allografts with lower post-operative anterior knee translation on KT-1000 and lower rates of reoperation (19). Other comparative studies and case series have suggested a similar conclusion, with allograft use being associated with higher ACL graft failure and a 2.2 times higher risk of revision ACLR when compared to autograft (20,21).

The most common choice for autograft in the revision setting has historically been BPTB given its success in the literature with long-term follow-up (22). More recently, QT autograft has become increasingly popular in revision ACLR and the use of HT autograft has declined. This is due to recent cohort studies in the literature supporting equivalent outcomes between BPTB and QT autograft and an increased failure rate with HT autograft (23,24). With popular graft choices being BPTB and QT autograft, the following question arises in decision-making—can we use BPTB autograft if QT autograft was used in the index procedure (or vice versa)? Research has shown that it is safe to harvest two extensor mechanism grafts in the revision setting (BPTB followed by QT or QT followed by BPTB). In a study by Setliff et al. (2023), patients with two previous extensor mechanism graft harvests in the ipsilateral limb had similar clinical outcomes and RTS rates compared to patients with one extensor mechanism graft harvest in revision ACLR (25).

When selecting the appropriate graft for the high-level athlete in revision ACLR, the authors recommend the use of autograft, and this should be catered based on the graft used in the primary ACLR. Based on the available literature, we recommend the use of BPTB or QT autograft, given the higher ACL graft failure rates observed with HT use. We prefer to harvest a BPTB in a patient with a previous QT autograft, or a QT in a patient with a previous BPTB autograft, unless there is extensor mechanism insufficiency. In this setting, HT autograft, contralateral BPTB autograft, or contralateral QT autograft are reasonable alternatives.

Concomitant injuries

It is important to recognize that concomitant injuries in the setting of revision ACLR may be either injuries that were missed at the time of primary ACLR and have now potentially contributed to ACL graft failure, or new injuries that have occurred since the primary ACLR. To differentiate the two, it can be helpful to review the initial MRI prior to the primary ACLR and compare it to the new MRI following ACL graft failure. If available, it would also be useful to review the intraoperative arthroscopic photographs. This can be beneficial in identifying if a concomitant meniscus or collateral injury was missed during the index ACLR and should be addressed during revision ACLR. Identification and surgical treatment of associated meniscus or collateral ligament injury is crucial in maximizing future success, improving the patient’s future outcome with respect to patient-reported outcome measures as well as lowering the chance of ACL graft failure following revision ACLR.

In terms of meniscal pathology, medial meniscus ramp lesions and lateral meniscus root tears are found in up to 52% of primary and revision ACLR. If missed, these lesions predispose the patient to persistent rotatory knee instability (26). These injuries must be identified and repaired during revision ACLR in the high-level athlete to decrease the overall stress on the ACL graft and thereby prevent future ACL graft failure after RTS.

It is also important to identify whether there was injury to other ligaments at the time of the index surgery. Medial collateral ligament (MCL) injury has been reported in up to 67% of ACL ruptures. If significant MCL insufficiency is not addressed, this may lead to persistent anteromedial rotatory knee instability, resulting in possible meniscal injury and ACL graft failure (27,28). If a missed MCL injury with MCL insufficiency is identified, it should be addressed with a concomitant MCL reconstruction during revision ACLR to restore appropriate knee biomechanics (29-31). Lastly, missed injury to the posterolateral corner (PLC) should be assessed in the revision setting. Deficiency of the PLC at the time of primary ACLR has been shown to lead to an increased risk of ACL graft failure due to posterolateral laxity and varus load on the ACL graft (32). If a missed PLC injury is noted during revision ACLR, this should be addressed with a concomitant PLC reconstruction during revision ACLR to improve patient outcomes and decrease ACL graft failure rates (33).

When to consider concomitant anterolateral procedures?

One of the proposed causes of ACL graft failure is persistent, unaddressed rotatory knee instability. Anterolateral augmentation procedures during ACLR have been shown to control rotatory knee instability compared to isolated ACLR in cadaveric studies (34). While data from the STABILITY trial (a randomized controlled trial) supports the use of lateral extra-articular tenodesis (LET) in the primary ACLR setting with certain autograft choices, commonly cited indications for LET or anterolateral ligament (ALL) reconstruction in revision ACLR are less agreed upon (35). LET or ALL reconstruction is often recommended during revision ACLR in young patients with knee hyperlaxity and athletes that participate in pivoting sports, multiple revision ACLR situations, patients with high-grade pivot shifts (clunk or locking), and increased PTS not meeting criteria for slope correcting osteotomy (35). Additionally, LET or ALL reconstruction may be performed during revision ACLR as an augment when the etiology for the primary ACL graft failure is not understood (i.e., adequate tunnel placement with acceptable sagittal and coronal alignment). Table 1 displays indications for LET.

Although several techniques for LET exist, a common choice is the modified Lemaire procedure, in which a strip of the iliotibial band attached to Gerdy’s tubercle is passed deep to the lateral collateral ligament (LCL) and fixated proximal to the LCL insertion on the lateral femoral epicondyle (36). Several techniques have also been described for ALL reconstruction. In a recent systematic review, the most common technique involved femoral graft fixation posterior and proximal to the attachment of the LCL, and tibial graft fixation at a point equidistant between Gerdy’s tubercle and the fibular head, with the most commonly used graft being gracilis allograft (37). Short-term outcomes of revision ACLR with LET demonstrate decreased ACL graft failure rates and decreased incidence of a positive pivot shift postoperatively (38). In addition, comparative studies have displayed a significant reduction in ACL graft failure rates and improvement in return to preinjury level of sports has been reported following revision ACLR with LET compared with revision ACLR without LET (38-41). To conclude, although data are limited and most published literature on this topic are of low-level evidence in revision ACLR, in the setting of a young (<25 years of age) pivoting or cutting athlete with knee hyperextension, a high-grade pivot shift, and increased PTS not meeting criteria for slope correcting osteotomy, adding an anterolateral augmentation procedure to the revision ACLR may be beneficial.

When to consider staging?

Revision ACLR can be performed in a single-stage or two-stage fashion. Factors such as tunnel malposition, tunnel osteolysis, coronal or sagittal malalignment, and concomitant soft-tissue injuries play a role in the decision-making process regarding when to stage (35). Patients with anatomic or semi-anatomic tunnels without excessive osteolysis (≤14 mm) or with tunnels that have been previously positioned inappropriately and do not interfere with new intended tunnel placement (Figure 4) may be indicated for a single-stage revision ACLR (16,22). Meniscal and chondral pathologic conditions should be addressed in the revision ACLR setting, whether in the first stage or second stage. Corrective osteotomies can also be performed concomitantly with revision ACLR in a single or two-stage procedure, based on surgeon’s discretion. If performed in a single stage with concomitant revision ACLR, thoughtful placement of hardware and tunnels is necessary to avoid graft impingement, damage, or rigid fixation failure.

Figure 4 Intraoperative images from an anterior arthroscopic view of the lateral femoral notch during revision ACLR. Earlier femoral fixation hardware can be seen left in place (asterisks) while new anatomic femoral tunnel is created more posteriorly, as it does not interfere with revision tunnel placement. ACLR, anterior cruciate ligament reconstruction.

A two-stage procedure is often indicated when mal-positioned tunnels affect the placement of new tunnels or tunnel osteolysis of 15 mm or greater is present. Additionally, an initial stage may be employed to fully evaluate meniscal or chondral injury, which would be addressed in a subsequent second-stage procedure. Special consideration must be taken when electing for a two-stage procedure, as they typically require a 3–6 month interval between procedures, which may theoretically place the patient at an increased risk for further chondral or meniscal injury due to prolonged knee instability between stages (35). This theoretical risk may be mitigated, however, if the athlete is instructed to avoid vigorous, side-to-side activities between procedures. Yet, given this risk, a two-stage revision should be reserved for when a single-stage procedure may not be satisfactorily performed.

During a single-stage procedure, management of prior tunnels mandates attention. Previous tunnels may be avoided based on their location; however, new tunnel overlapping with prior tunnels is not a hard contraindication to single-stage revision. If necessary, prior tunnels can be filled with bone graft or bone substitute and redrilled, or a divergent tunnel technique may be used (Figure 5). Any retained hardware can be removed, left in place if not interfering with revision tunnel placement, or drilled through. Confirmation should be made that all granulation and foreign material have been removed from the new tunnel. It is important to ensure rigid fixation of the graft, and stacked screws should be avoided due to the risk of graft compromise (42). If fixation is at all questionable, the revision procedure should be deferred to a second stage.

Figure 5 Intraoperative images from an anterior arthroscopic view of the lateral femoral notch during revision ACLR. From left to right, the photos demonstrate (I) a previous non-anatomic tunnel (red asterisk), (II) placement of an allograft bone dowel into the previous tunnel (red asterisk), (III) subsequent single stage drilling posterior to the prior tunnel with minor overlap with the allograft bone dowel (allograft bone dowel marked with red asterisk), and (IV) the new tunnel for single stage revision ACLR. ACLR, anterior cruciate ligament reconstruction.

A main reason to indicate a two-stage procedure is to address tunnel defects that may not allow for a successful single-stage procedure in terms of accurate tunnel placement. During the first stage, the tibial and femoral tunnels should be fully debrided and visualized for proper characterization. All loose hardware should be removed, and bone grafting of tunnels may be achieved using allograft (chips or dowels), autograft, or bone substitutes. Our group prefers using allograft bone dowels in this setting. Once the prior tunnels are addressed, corrective osteotomies or additional procedures for concomitant meniscal, chondral, or ligamentous injury may also be performed. After this initial procedure, the second stage can be performed once CT has confirmed incorporation of the bone graft, typically within 3–6 months.

Although evidence is limited, the literature suggests equivalent outcomes following single-stage versus two-stage revision ACLR (43). At 2-year follow-up, a retrospective comparative study found no differences in subjective outcomes or ACL graft failure rates between groups undergoing revision ACLR in a single or two-staged manner; however, patients undergoing two-stage revision ACLR were predisposed to additional intra-articular lesions and a longer surgical recovery. A systematic analysis comparing outcomes between single-stage and two-stage revision ACLR found no significant difference in rate of repeat revision surgery following single-stage versus two-stage revision ACLR (3.1% vs. 6.8%) and equivalent clinical outcomes (44). Lastly, a 2021 retrospective case series of 91 patients which included 40 “elite athletes”, defined as professionals or semi-professionals, undergoing single-stage revision ACLR concluded that revision ACLR in a single stage manner can be performed reliably with successful outcomes in terms of patient-reported outcomes and RTS rates (87.5% of elite athletes at mean 11.2 months) as well as low ACL graft failure rates (45). When possible, the senior author recommends single-stage revision ACLR in the high-level athlete to avoid prolonged recovery time and RTS, ACL-deficient interval, and need for a second surgery. However, in certain settings, two-stage procedures may be necessary so that success rates are not compromised.

When to correct coronal and sagittal malalignment in revision ACLR?

Lower limb coronal and sagittal malalignment has been shown to increase stress on the native ACL and is associated with an increased risk of ACL graft failure (46). Specifically, increased PTS and severe varus malalignment are considered indications for combined osteotomy during revision ACLR. In patients with increased PTS, an anterior closing-wedge high tibial osteotomy (ACW-HTO) may be performed to reduce the tibial slope and prevent future ACL graft failure (8). Relative indications for ACW-HTO include patients who have sustained at least one ACL graft failure with an increased PTS greater than 12 degrees, body mass index (BMI) less than 30 kg/m², and without varus malalignment greater than 5 degrees (Table 2) (47). Case series have reported that combined revision ACLR with ACW-HTO results in improved patient-reported outcomes and clinical outcomes, reduction in ATT, and reduction in mean PTS postoperatively (ranging from 4 to 9 degrees of slope reduction) (8,47,48). Little data are present examining populations of high-level athletes specifically, but some case studies exist that provide promising evidence for the use of osteotomy in high-level athletes. A case series of 64 patients undergoing multiple revised ACLR with slope-reducing osteotomies showed that the ACW-HTO resulted in restored knee stability and improved function with acceptable complication rates (49). Utilizing the University of California and Los Angeles (UCLA) activity score, 52 patients (81.2%) returned to moderately active sports as reported by the authors, whereas 16 (25.0%) returned to preinjury level. The most common reason for not returning to impact sports (24/33 patients; 72.7%) was knee-related issues (49).

Although much attention has been focused on correcting PTS during revision ACLR, correcting varus deformity is also important for preventing future knee instability, ACL graft failure, and knee osteoarthritis (50). In such cases, a medial opening wedge-HTO (MOW-HTO) or a lateral closing wedge-HTO (LCW-HTO) may be performed. Relative indications for these procedures include patient age younger than 60 years, BMI less than 30 kg/m², intact menisci and cartilage, and unicompartmental mild-to-moderate osteoarthritis. A systematic review of 18 studies reported that simultaneous high tibial osteotomy and ACLR was effective in correcting varus malalignment and reducing ACL graft failure following revision ACLR (51). As with ACW-HTO, data on MOW-HTO and LCW-HTO in the setting of revision ACLR in elite athletes are limited. A recent study of case series 35 athletes with combined ACLR and MOW-HTO at 10-year follow-up reported an 80% RTS rate, 31% rate of return to prior activity level, and 10% ACL graft failure rate (52).

Overall, while evidence exists to promote the implementation of slope-reducing and valgusating osteotomies in the revision ACLR setting to correct sagittal and coronal malalignment and improve ACL graft failure rates, further research is needed, specifically in the elite athlete population to determine these osteotomies’ effectiveness in returning athletes to sport at their previous level of performance. Given this, surgeons should have caution when discussing osteotomy with an elite athlete who wishes to return to preinjury level of sports.

RTS overview

RTS following revision ACLR is a multifaceted process influenced by numerous factors, including graft choice, functional assessment metrics, rehabilitation protocols, and psychological readiness of the patient. Here, we discuss RTS as a continuum and review RTS rates presented in the literature.

RTS—a continuum

RTS following ACLR in the high-level athlete is best viewed on a continuum and may vary based on the individual athlete. Operative limb strength, dynamic movements, and psychological readiness must all be considered and maximized prior to RTS. Rigid time-based rehabilitation protocols cannot reflect an individual athlete’s capabilities accurately and should rather be replaced by criteria-based protocols (53-56). To achieve a successful outcome in the high-level athlete, RTS should be based on a shared decision-making platform, involving the patient within a multidisciplinary biopsychosocial framework (57).

In modern RTS protocols, trends have moved away from purely time-based criteria to protocols that include both physical and psychological readiness. In terms of physical testing, athletes typically undergo a multitude of tests which include lower extremity strength side-to-side comparison (limb symmetry index), hop tests (single hop for distance, triple hop, triple cross-over hop, timed 10-meter hop, side hop), single leg vertical jump, single leg drop vertical jump, and double leg drop vertical jump (58). These objective criteria are used to determine the athlete’s readiness to progress within the RTS continuum from a physical conditioning standpoint. At the senior author’s institution, criteria-based clearance for RTS is centered around the tests mentioned above. Objective “clearance” for all tests is defined as reaching ≥90% of the uninjured limb. More recently, performing sports-specific testing and “on-field” rehabilitation has been recommended once sufficient strength and conditioning have been achieved in order to lower the chance of re-injury (59). Literature has shown that athletes who do not meet discharge criteria in terms of RTS testing have a four times greater risk of ACL graft failure compared to those who meet all RTS criteria (60). One cohort study showed that 5.6% of patients who passed RTS criteria before returning to pivoting sports suffered an ACL graft failure compared with 38.2% who did not in the primary ACLR setting (61). In the high-level athlete, we recommend following a protocol that starts with strength and dynamic movements and moves towards sports-specific activities prior to full RTS clearance.

Time to RTS should also be considered in addition to physical parameters, as it has been evaluated in the literature as a risk factor for ACL graft failure. Current literature suggests that RTS is often permitted at 6–9 months postoperatively, although significant variability exists in the criteria used to determine readiness (62). A systematic review of level 1 literature found that while 51% of studies allowed unrestricted return to cutting and pivoting sports at 6 months, nearly 25% of studies failed to report any clear RTS criteria (62). Delaying RTS beyond 9 months has been associated with a reduced risk of re-injury, with one study noting a 51% reduction in ACL graft failure risk for each additional month RTS was delayed up to 9 months (60). Given these findings, in order to maximize success following revision ACLR in high-level athletes, we recommend delaying RTS until at least the 9-month mark post-operatively in the revision ACLR setting, in combination with RTS physical testing.

In addition to physical and time-based parameters, psychological readiness must be considered as a determinant for successful RTS. Significant fear of re-injury and lack of confidence in the operative knee can negatively impact an athlete’s ability to RTS successfully (63). One tool that is currently being used to assess psychological readiness to RTS is the ACL Return to Sport After Injury (ACL-RSI) scale. It was introduced in 2008 and is the only validated scale specific to ACL injury (64). Scores on this scale are predictive of RTS, self-rated sports performance, and even further ACL injury (65-67). It includes a series of 12 questions containing themes surrounding confidence in the knee, fear of re-injury, and other emotions surrounding RTS (64). The three domains represented are emotions, confidence, and risk appraisal, with scores for each item averaged for a total score between 0 and 100. Currently, scores of greater than 60 have been shown to predict psychological readiness to return (66). Our group tends to use this test in the setting of our high-level athletes returning to sport as a part of the RTS continuum. The test is administered as they start to perform sports-specific training and repeated as needed as a full RTS approach.

RTS rates

In the available literature, some studies have shown equivalent RTS between primary and revision ACLR, while other studies have shown significantly lower RTS rates following revision ACLR. A prospective cohort study of 55 revision ACLR and 497 primary ACLR found no significant differences in RTS rate at 1 year between primary ACLR (90.0%) and revision ACLR (87.3%) (68). Similarly, a case series comparing RTS between primary and revision ACLR showed no differences in RTS between the two groups, with 46% of revision ACLR returning to pre-injury level of sports compared to 50% after primary ACLR (69). Other studies have shown lower rates of RTS in the revision ACLR setting when compared to primary ACLR. In a more recent retrospective study of 124 patients who had undergone primary or revision ACLR, it was found that at a mean follow-up of 49 months, the rate of RTS at same level in revision ACLR was 14.5% lower than primary ACLR and the average time to RTS was 6 weeks longer (70). A separate meta-analysis of 31 studies confirmed similar results showing that return to preinjury level of sports was significantly lower (57%) in revision ACLR compared to primary ACLR (82%) (71). In another single-center cohort study, which focused on RTS after revision ACLR at 2-year follow-up, RTS at same level in revision ACLR was 17%, and return to a lower level of performance was 45.6% (72). In the multiple revision ACLR setting, this same study showed a return to both same level and lower level of performance of 14% (72). They also found that patients who underwent multiple revision ACLR stopped all sports activity completely at a higher rate (single-revision ACLR group: 19.4%; multiple-revision ACLR group: 50%) (72). Based on the available literature, it is therefore important to have a discussion with the high-level athlete prior to embarking on revision ACLR, focusing on a potential lower chance of RTS at same level.

Conclusions

Revision ACLR in the high-level athlete is a complex problem that requires a thoughtful approach. Pre-operatively, one must consider tunnel position, graft selection, whether concomitant injuries must be addressed, whether alignment in the coronal or sagittal planes should be corrected, whether staging is required, and whether adding an anterolateral augmentation procedure will be beneficial. One must also consider the athlete’s goals regarding RTS, including anticipated level of return. Post-operatively, successful RTS should be a continuum, incorporating time, psychological readiness, strength, and dynamic movements. Literature suggests that RTS should be delayed for at least 9 months, combined with successful RTS testing, in order to maximize success.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was commissioned by the Guest Editors (Jeremy Burnham, Brian Godshaw and Patrick Cook) for the series “Evaluation and Treatment of ACL Injuries in High Level Athletes: The Continuum of Care” published in Annals of Joint. The article has undergone external peer review.

Peer Review File: Available at https://aoj.amegroups.com/article/view/10.21037/aoj-25-25/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://aoj.amegroups.com/article/view/10.21037/aoj-25-25/coif). The series “Evaluation and Treatment of ACL Injuries in High Level Athletes: The Continuum of Care” was commissioned by the editorial office without any funding or sponsorship. J.D.H. serves as an unpaid editorial board member of Annals of Joint from July 2024 to December 2026. J.D.H. reports that he serves as a paid consultant for Smith and Nephew and is a member of the editorial board of the journal Knee Surgery, Sports Traumatology, Arthroscopy (KSSTA). The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Li X, Yan L, Li D, et al. Failure modes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis. Int Orthop 2023;47:719-34. [Crossref] [PubMed]
2. Diquattro E, Jahnke S, Traina F, et al. ACL surgery: reasons for failure and management. EFORT Open Rev 2023;8:319-30. [Crossref] [PubMed]
3. Paterno MV, Rauh MJ, Schmitt LC, et al. Incidence of contralateral and ipsilateral anterior cruciate ligament (ACL) injury after primary ACL reconstruction and return to sport. Clin J Sport Med 2012;22:116-21. [Crossref] [PubMed]
4. Lee TF, Drake SM, Roberts GW, et al. Relative Hyperglycemia Is an Independent Determinant of In-Hospital Mortality in Patients With Critical Illness. Crit Care Med 2020;48:e115-22. [Crossref] [PubMed]
5. George MS, Dunn WR, Spindler KP. Current concepts review: revision anterior cruciate ligament reconstruction. Am J Sports Med 2006;34:2026-37. [Crossref] [PubMed]
6. Chen JL, Allen CR, Stephens TE, et al. Differences in mechanisms of failure, intraoperative findings, and surgical characteristics between single- and multiple-revision ACL reconstructions: a MARS cohort study. Am J Sports Med 2013;41:1571-8. [Crossref] [PubMed]
7. MARS Group. Descriptive epidemiology of the Multicenter ACL Revision Study (MARS) cohort. Am J Sports Med 2010;38:1979-86. [Crossref] [PubMed]
8. Dejour D, Saffarini M, Demey G, et al. Tibial slope correction combined with second revision ACL produces good knee stability and prevents graft rupture. Knee Surg Sports Traumatol Arthrosc 2015;23:2846-52. [Crossref] [PubMed]
9. Morgan JA, Dahm D, Levy B, et al. Femoral tunnel malposition in ACL revision reconstruction. J Knee Surg 2012;25:361-8. [Crossref] [PubMed]
10. Vermeijden HD, Yang XA, van der List JP, et al. Trauma and femoral tunnel position are the most common failure modes of anterior cruciate ligament reconstruction: a systematic review. Knee Surg Sports Traumatol Arthrosc 2020;28:3666-75. [Crossref] [PubMed]
11. Bernard M, Hertel P, Hornung H, et al. Femoral insertion of the ACL. Radiographic quadrant method. Am J Knee Surg 1997;10:14-21; discussion 21-2.
12. Harner CD, Marks PH, Fu FH, et al. Anterior cruciate ligament reconstruction: endoscopic versus two-incision technique. Arthroscopy 1994;10:502-12. [Crossref] [PubMed]
13. Stäubli HU, Rauschning W. Tibial attachment area of the anterior cruciate ligament in the extended knee position. Anatomy and cryosections in vitro complemented by magnetic resonance arthrography in vivo. Knee Surg Sports Traumatol Arthrosc 1994;2:138-46. [Crossref] [PubMed]
14. Illingworth KD, Hensler D, Working ZM, et al. A simple evaluation of anterior cruciate ligament femoral tunnel position: the inclination angle and femoral tunnel angle. Am J Sports Med 2011;39:2611-8. [Crossref] [PubMed]
15. Forsythe B, Kopf S, Wong AK, et al. The location of femoral and tibial tunnels in anatomic double-bundle anterior cruciate ligament reconstruction analyzed by three-dimensional computed tomography models. J Bone Joint Surg Am 2010;92:1418-26. [Crossref] [PubMed]
16. Kamath GV, Redfern JC, Greis PE, et al. Revision anterior cruciate ligament reconstruction. Am J Sports Med 2011;39:199-217. [Crossref] [PubMed]
17. Factors Influencing Graft Choice in Revision Anterior Cruciate Ligament Reconstruction in the MARS Group. J Knee Surg 2016;29:458-63. [Crossref] [PubMed]
18. Mohan R, Webster KE, Johnson NR, et al. Clinical Outcomes in Revision Anterior Cruciate Ligament Reconstruction: A Meta-analysis. Arthroscopy 2018;34:289-300. [Crossref] [PubMed]
19. Grassi A, Nitri M, Moulton SG, et al. Does the type of graft affect the outcome of revision anterior cruciate ligament reconstruction? a meta-analysis of 32 studies. Bone Joint J 2017;99-B:714-23. [Crossref] [PubMed]
20. Nissen KA, Eysturoy NH, Nielsen TG, et al. Allograft Use Results in Higher Re-revision Rate for Revision Anterior Cruciate Ligament Reconstruction. Orthop J Sports Med 2018;6:2325967118775381. [Crossref] [PubMed]
21. Winkler PW, Wagala NN, Hughes JD, et al. A high tibial slope, allograft use, and poor patient-reported outcome scores are associated with multiple ACL graft failures. Knee Surg Sports Traumatol Arthrosc 2022;30:139-48. [Crossref] [PubMed]
22. Dadoo S, Benvegnu N, Herman ZJ, et al. Revision Anterior Cruciate Ligament Reconstruction and Associated Procedures. Clin Sports Med 2024;43:449-64. [Crossref] [PubMed]
23. Runer A, Csapo R, Hepperger C, et al. Anterior Cruciate Ligament Reconstructions With Quadriceps Tendon Autograft Result in Lower Graft Rupture Rates but Similar Patient-Reported Outcomes as Compared With Hamstring Tendon Autograft: A Comparison of 875 Patients. Am J Sports Med 2020;48:2195-204. [Crossref] [PubMed]
24. Winkler PW, Vivacqua T, Thomassen S, et al. Quadriceps tendon autograft is becoming increasingly popular in revision ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 2022;30:149-60. [Crossref] [PubMed]
25. Setliff JC, Gibbs CM, Musahl V, et al. Harvesting a second graft from the extensor mechanism for revision ACL reconstruction does not delay return of quadriceps function. Knee Surg Sports Traumatol Arthrosc 2023;31:2828-35. [Crossref] [PubMed]
26. Magosch A, Mouton C, Nührenbörger C, et al. Medial meniscus ramp and lateral meniscus posterior root lesions are present in more than a third of primary and revision ACL reconstructions. Knee Surg Sports Traumatol Arthrosc 2021;29:3059-67. [Crossref] [PubMed]
27. Willinger L, Balendra G, Pai V, et al. High incidence of superficial and deep medial collateral ligament injuries in 'isolated' anterior cruciate ligament ruptures: a long overlooked injury. Knee Surg Sports Traumatol Arthrosc 2022;30:167-75. [Crossref] [PubMed]
28. Alm L, Drenck TC, Frings J, et al. Lower Failure Rates and Improved Patient Outcome Due to Reconstruction of the MCL and Revision ACL Reconstruction in Chronic Medial Knee Instability. Orthop J Sports Med 2021;9:2325967121989312. [Crossref] [PubMed]
29. Behrendt P, Herbst E, Robinson JR, et al. The Control of Anteromedial Rotatory Instability Is Improved With Combined Flat sMCL and Anteromedial Reconstruction. Am J Sports Med 2022;50:2093-101. [Crossref] [PubMed]
30. Miyaji N, Holthof SR, Ball SV, et al. Medial Collateral Ligament Reconstruction for Anteromedial Instability of the Knee: A Biomechanical Study In Vitro. Am J Sports Med 2022;50:1823-31. [Crossref] [PubMed]
31. Ball S, Stephen JM, El-Daou H, et al. The medial ligaments and the ACL restrain anteromedial laxity of the knee. Knee Surg Sports Traumatol Arthrosc 2020;28:3700-8. [Crossref] [PubMed]
32. Kim SJ, Choi DH, Hwang BY. The influence of posterolateral rotatory instability on ACL reconstruction: comparison between isolated ACL reconstruction and ACL reconstruction combined with posterolateral corner reconstruction. J Bone Joint Surg Am 2012;94:253-9. [Crossref] [PubMed]
33. Bonanzinga T, Zaffagnini S, Grassi A, et al. Management of Combined Anterior Cruciate Ligament-Posterolateral Corner Tears: A Systematic Review. Am J Sports Med 2014;42:1496-503. [Crossref] [PubMed]
34. Marom N, Ouanezar H, Jahandar H, et al. Lateral Extra-articular Tenodesis Reduces Anterior Cruciate Ligament Graft Force and Anterior Tibial Translation in Response to Applied Pivoting and Anterior Drawer Loads. Am J Sports Med 2020;48:3183-93. [Crossref] [PubMed]
35. Miller MD, Kew ME, Quinn CA. Anterior Cruciate Ligament Revision Reconstruction. J Am Acad Orthop Surg 2021;29:723-31. [Crossref] [PubMed]
36. Inderhaug E, Stephen JM, Williams A, et al. Anterolateral Tenodesis or Anterolateral Ligament Complex Reconstruction: Effect of Flexion Angle at Graft Fixation When Combined With ACL Reconstruction. Am J Sports Med 2017;45:3089-97. [Crossref] [PubMed]
37. DePhillipo NN, Cinque ME, Chahla J, et al. Anterolateral Ligament Reconstruction Techniques, Biomechanics, and Clinical Outcomes: A Systematic Review. Arthroscopy 2017;33:1575-83. [Crossref] [PubMed]
38. Alm L, Drenck TC, Frosch KH, et al. Lateral extra-articular tenodesis in patients with revision anterior cruciate ligament (ACL) reconstruction and high-grade anterior knee instability. Knee 2020;27:1451-7. [Crossref] [PubMed]
39. Borque KA, Jones M, Laughlin MS, et al. Effect of Lateral Extra-articular Tenodesis on the Rate of Revision Anterior Cruciate Ligament Reconstruction in Elite Athletes. Am J Sports Med 2022;50:3487-92. [Crossref] [PubMed]
40. Grassi A, Zicaro JP, Costa-Paz M, et al. Good mid-term outcomes and low rates of residual rotatory laxity, complications and failures after revision anterior cruciate ligament reconstruction (ACL) and lateral extra-articular tenodesis (LET). Knee Surg Sports Traumatol Arthrosc 2020;28:418-31. [Crossref] [PubMed]
41. Keizer MNJ, Brouwer RW, de Graaff F, et al. Higher return to pre-injury type of sports after revision anterior ligament reconstruction with lateral extra-articular tenodesis compared to without lateral extra-articular tenodesis. Knee Surg Sports Traumatol Arthrosc 2023;31:1699-703. [Crossref] [PubMed]
42. Schliemann B, Treder M, Schulze M, et al. Influence of Different Tibial Fixation Techniques on Initial Stability in Single-Stage Anterior Cruciate Ligament Revision With Confluent Tibial Tunnels: A Biomechanical Laboratory Study. Arthroscopy 2016;32:78-89. [Crossref] [PubMed]
43. Mitchell JJ, Chahla J, Dean CS, et al. Outcomes After 1-Stage Versus 2-Stage Revision Anterior Cruciate Ligament Reconstruction. Am J Sports Med 2017;45:1790-8. [Crossref] [PubMed]
44. Mathew CJ, Palmer JE, Lambert BS. er al. Single-stage versus two-stage revision anterior cruciate ligament reconstruction: a systematic review. J ISAKOS 2018;3:345-51.
45. White NP, Borque KA, Jones MH, et al. Single-Stage Revision Anterior Cruciate Ligament Reconstruction: Experience With 91 Patients (40 Elite Athletes) Using an Algorithm. Am J Sports Med 2021;49:364-73. [Crossref] [PubMed]
46. Tischer T, Condello V, Menetrey J, et al. Time to focus on ACL revision: ESSKA 2022 consensus. Knee Surg Sports Traumatol Arthrosc 2023;31:4637-8. [Crossref] [PubMed]
47. Vivacqua T, Thomassen S, Winkler PW, et al. Closing-Wedge Posterior Tibial Slope-Reducing Osteotomy in Complex Revision ACL Reconstruction. Orthop J Sports Med 2023;11:23259671221144786. [Crossref] [PubMed]
48. Akoto R, Alm L, Drenck TC, et al. Slope-Correction Osteotomy with Lateral Extra-articular Tenodesis and Revision Anterior Cruciate Ligament Reconstruction Is Highly Effective in Treating High-Grade Anterior Knee Laxity. Am J Sports Med 2020;48:3478-85. [Crossref] [PubMed]
49. Mabrouk A, Kley K, Jacquet C, et al. Outcomes of Slope-Reducing Proximal Tibial Osteotomy Combined With a Third Anterior Cruciate Ligament Reconstruction Procedure With a Focus on Return to Impact Sports. Am J Sports Med 2023;51:3454-63. [Crossref] [PubMed]
50. Cantin O, Magnussen RA, Corbi F, et al. The role of high tibial osteotomy in the treatment of knee laxity: a comprehensive review. Knee Surg Sports Traumatol Arthrosc 2015;23:3026-37. [Crossref] [PubMed]
51. Stride D, Wang J, Horner NS, et al. Indications and outcomes of simultaneous high tibial osteotomy and ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 2019;27:1320-31. [Crossref] [PubMed]
52. Schneider A, Gaillard R, Gunst S, et al. Combined ACL reconstruction and opening wedge high tibial osteotomy at 10-year follow-up: excellent laxity control but uncertain return to high level sport. Knee Surg Sports Traumatol Arthrosc 2020;28:960-8. [Crossref] [PubMed]
53. Adams D, Logerstedt DS, Hunter-Giordano A, et al. Current concepts for anterior cruciate ligament reconstruction: a criterion-based rehabilitation progression. J Orthop Sports Phys Ther 2012;42:601-14. [Crossref] [PubMed]
54. Meredith SJ, Rauer T, Chmielewski TL, et al. Return to Sport After Anterior Cruciate Ligament Injury: Panther Symposium ACL Injury Return to Sport Consensus Group. Orthop J Sports Med 2020;8:2325967120930829.
55. Musahl V, Engler ID, Nazzal EM, et al. Current trends in the anterior cruciate ligament part II: evaluation, surgical technique, prevention, and rehabilitation. Knee Surg Sports Traumatol Arthrosc 2022;30:34-51. [Crossref] [PubMed]
56. Vascellari A, Gokeler A, Grassi A, et al. Functional progression milestones following anterior cruciate ligament reconstruction are more appropriate than time-based criteria: a survey among the ESSKA. Knee Surg Sports Traumatol Arthrosc 2020;28:3647-54. [Crossref] [PubMed]
57. Ardern CL, Glasgow P, Schneiders A, et al. 2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern. Br J Sports Med 2016;50:853-64.
58. Gustavsson A, Neeter C, Thomeé P, et al. A test battery for evaluating hop performance in patients with an ACL injury and patients who have undergone ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 2006;14:778-88. [Crossref] [PubMed]
59. Wilk K, Thomas ZM, Arrigo CA, et al. The Need To Change Return to Play Testing in Athletes Following ACL Injury: A Theoretical Model. Int J Sports Phys Ther 2023;18:272-81. [Crossref] [PubMed]
60. Kaplan Y, Witvrouw E. When Is It Safe to Return to Sport After ACL Reconstruction? Reviewing the Criteria. Sports Health 2019;11:301-5. [Crossref] [PubMed]
61. Grindem H, Snyder-Mackler L, Moksnes H, et al. Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction: the Delaware-Oslo ACL cohort study. Br J Sports Med 2016;50:804-8. [Crossref] [PubMed]
62. Harris JD, Abrams GD, Bach BR, et al. Return to sport after ACL reconstruction. Orthopedics 2014;37:e103-8. [Crossref] [PubMed]
63. Ardern CL, Österberg A, Tagesson S, et al. The impact of psychological readiness to return to sport and recreational activities after anterior cruciate ligament reconstruction. Br J Sports Med 2014;48:1613-9. [Crossref] [PubMed]
64. Webster KE, Feller JA, Lambros C. Development and preliminary validation of a scale to measure the psychological impact of returning to sport following anterior cruciate ligament reconstruction surgery. Phys Ther Sport 2008;9:9-15. [Crossref] [PubMed]
65. McPherson AL, Feller JA, Hewett TE, et al. Psychological Readiness to Return to Sport Is Associated With Second Anterior Cruciate Ligament Injuries. Am J Sports Med 2019;47:857-62. [Crossref] [PubMed]
66. Webster KE, Feller JA. Development and Validation of a Short Version of the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) Scale. Orthop J Sports Med 2018;6:2325967118763763. [Crossref] [PubMed]
67. Webster KE, McPherson AL, Hewett TE, et al. Factors Associated With a Return to Preinjury Level of Sport Performance After Anterior Cruciate Ligament Reconstruction Surgery. Am J Sports Med 2019;47:2557-62. [Crossref] [PubMed]
68. Lefevre N, Klouche S, Mirouse G, et al. Return to Sport After Primary and Revision Anterior Cruciate Ligament Reconstruction: A Prospective Comparative Study of 552 Patients From the FAST Cohort. Am J Sports Med 2017;45:34-41. [Crossref] [PubMed]
69. Anand BS, Feller JA, Richmond AK, et al. Return-to-Sport Outcomes After Revision Anterior Cruciate Ligament Reconstruction Surgery. Am J Sports Med 2016;44:580-4. [Crossref] [PubMed]
70. Mardani-Kivi M, Leili EK, Shirangi A, et al. Return to sports activity in the revision of anterior cruciate ligament reconstruction: A 2-6 Year follow-up study. J Clin Orthop Trauma 2021;16:80-5. [Crossref] [PubMed]
71. Andriolo L, Filardo G, Kon E, et al. Revision anterior cruciate ligament reconstruction: clinical outcome and evidence for return to sport. Knee Surg Sports Traumatol Arthrosc 2015;23:2825-45. [Crossref] [PubMed]
72. El Khoury G, Hardy A, Saint-Etienne A, et al. Return to Sport After Revision ACL Reconstruction: A Comparative Cohort Study of Outcomes After Single- Versus Multiple-Revision Surgeries. Orthop J Sports Med 2022;10:23259671221133762. [Crossref] [PubMed]