Individualized ACL reconstruction

Surgical Techniques in Primary ACL Reconstruction: Getting It Right the First Time

The ideal anterior cruciate ligament reconstruction (ACLR) is an individualized anatomic approach aimed at restoring the native structure and function of the knee. Surgeons are tasked with difficult decisions during operative planning, including the optimal graft choice for the patient and appropriate anatomic tunnel placement. Special considerations should additionally be given for skeletally immature patients and those at high-risk for failure, including younger, active patients participating in pivoting sports. The purpose of this review is to provide an overview of the individualized approach to ACLR, including the necessary preoperative and operative considerations to optimize patient outcomes.

ANTEROMEDIAL OR CENTRAL ANATOMIC ACL RECONSTRUCTION? A CADAVERIC HIP-TO-TOE STUDY

Objective

To compare anatomic anterior cruciate ligament (ACL) reconstruction between two tunnel positions in knees with isolated ligament tears.

Methods

Anatomic ACL reconstruction was performed, from hip-to-toe, on 15 fresh cadaveric specimens. No associated lesions were created to enhance knee instability. The protocol was conducted in three states: (1) complete isolated ACL deficiency; (2) anatomic femoral and tibial anteromedial ACL reconstruction (AM REC); and (3) anatomic femoral and tibial central ACL reconstruction (Central REC). The reconstruction protocols were randomly assigned. The continuous mechanized pivot-shift test was recorded dynamically with a tracking system.

Results

The Central REC group showed a smaller degree of internal rotation (0.6° ± 0.3° vs. 1.8° ± 0.3°, respectively, P < 0.05) and no difference in anterior translation (4.7 mm ± 0.4 mm vs. 4.5 mm ± 0.4 mm, respectively, P > 0.05) in the pivot-shift test, compared with the AM REC group.

Conclusion

The central anatomic ACL reconstruction resulted in greater restriction of internal rotation than the anteromedial anatomic ACL reconstruction. Experimental Study on Cadaver.

Limited evidence for graft selection in pediatric ACL reconstruction: a narrative review

Anterior cruciate ligament reconstruction is the preferred treatment to anterior cruciate ligament injury. With the increase in anterior cruciate ligament injuries in both adults and skeletally immature patients comes the need for individualized anterior cruciate ligament reconstruction graft selection whether it is the type of graft (auto vs. allograft) or the harvesting site (hamstrings, iliotibial band, quadriceps, patella). Several factors need to be considered preoperatively in order to optimize the patients' recovery and restore anterior cruciate ligament strength and function. These include age and bone maturity, preoperative knee flexor/extensor strength, sport participation, patient's needs and anatomical characteristics. This paper aims at bringing evidence supporting the use of a personalized approach in graft selection for faster and more efficient return to sport and propose a theoretical framework to support the approach.

Preoperative ultrasound predicts the intraoperative diameter of the quadriceps tendon autograft more accurately than preoperative magnetic resonance imaging for anterior cruciate ligament reconstruction

PURPOSE

Sizing of potential autografts is essential to match the native anterior cruciate ligament (ACL) dimensions when performing ACL reconstruction (ACLR). We aimed to investigate the accuracy and reliability of the thickness and cross-sectional area (CSA) assessments for the prediction of the intraoperative diameter of the QT autograft using preoperative ultrasound and MRI.

METHODS

Thirty patients (mean age ± standard deviation, 19.9 ± 5.0 years), who underwent ACLR using QT autograft, were included. The maximum thickness of the QT was assessed at 15 and 30 mm proximal using ultrasound with a long axis image, and at 15 mm proximal to the superior pole of the patella using MRI with a sagittal image. The CSA was assessed at the central 10 mm of the medial-lateral QT width at 30 mm proximal using ultrasound with a short axis image, and at 15 mm proximal to the superior pole of the patella using MRI with an axial image. Intraoperatively, QT autograft was harvested with a 10 mm width and the diameter was measured using a graft sizing device.

RESULTS

Intra- and inter-observer reliabilities of all measurements using ultrasound and MRI were good (Intra-class correlation coefficient, 0.720-0.941). Correlation coefficient with the intraoperative diameter of the QT autograft was higher in ultrasound (R = 0.738-0.791, P < 0.001) than MRI (R = 0.449-0.543, P = 0.002-0.013).

CONCLUSIONS

Preoperative ultrasound predicted the intraoperative diameter of the QT autograft more accurately than MRI. Ultrasound may be used clinically to assure a sufficiently large QT autograft diameter to match the diameter of the patient's native ACL.

LEVEL OF EVIDENCE

Level III.

Morphological Evaluation of the Quadriceps Tendon Using Preoperative Ultrasound in Anterior Cruciate Ligament Reconstruction

BACKGROUND

An evaluation of quadriceps tendon (QT) morphology preoperatively is an important step when selecting an individually appropriate autograft for anterior cruciate ligament (ACL) reconstruction. However, to our knowledge, there are no studies that have assessed the morphology of the entire QT in an ACL-injured knee preoperatively using ultrasound.

PURPOSE

We aimed to investigate the morphological characteristics of the QT using preoperative ultrasound in ACL-injured knees.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 33 patients (mean age, 26.0 ± 11.5 years) with a diagnosed ACL tear undergoing primary ACL reconstruction were prospectively included. Using ultrasound, short-axis images of the QT were acquired in 10-mm increments from 30 to 100 mm proximal to the superior pole of the patella. The length of the QT was determined by 2 contiguous images that did and did not contain the rectus femoris muscle belly. The width of the superficial and narrowest parts of the QT, the thickness of the central and thickest parts of the QT, and the cross-sectional area at the central 10 mm of the superficial QT width were measured at each assessment location. The estimated intraoperative diameter of the QT autograft was calculated using a formula provided in a previous study.

RESULTS

There were no significant relationships between QT morphology and any of the demographic data collected. The length of the QT was less than 70 mm in 45.5% of patients (15/33). The width, thickness, cross-sectional area, and estimated intraoperative diameter of the QT autograft were significantly greater at 30 mm than at 70 mm proximal to the superior pole of the patella.

CONCLUSION

Preoperative ultrasound may identify a QT that is too small for an all-soft tissue autograft in ACL reconstruction. Furthermore, harvesting a QT with a fixed width may result in autografts that are smaller proximally than they are distally. Assessing the morphology of the QT preoperatively using ultrasound may help surgeons to adequately reconstruct the native length and diameter of the ACL with a QT autograft.

Bone Versus All Soft Tissue Quadriceps Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To examine existing literature on objective and patient-reported outcomes and complications after anterior cruciate ligament reconstruction (ACLR) with bone-quadriceps-tendon (B-QT) or soft tissue-quadriceps tendon (S-QT) to further clarify the role of graft type in primary ACLR.

METHODS

In accordance with PRISMA guidelines, PubMed, Embase, and Medline were searched in October 2019 for English-language, human studies of all evidence levels on patients undergoing primary ACLR with B-QT or S-QT autograft.

RESULTS

24 of 1,381 studies satisfied criteria, with 20 using B-QT (1,534 patients, mean age 29.6 years [range 14 to 59], mean follow-up 41.2 months [range 12 to 120]) and 5 using S-QT (181 patients, mean age 32.4 years [range 15 to 58), mean follow-up 25.5 months [range 12 to 46]). International Knee Documentation Committee (IKDC) scores were 67.3 to 89.5 with B-QT and 80.4 to 81.6 with S-QT. Lysholm scores were 85.7 to 97.4 with B-QT and 81.6 to 89.2 with S-QT. More B-QT patients demonstrated rotatory laxity on pivot shift compared with S-QT (0% to 39% versus 0%, respectively). The most common complication was graft rupture, and no differences were observed between graft choices (B-QT 0% to 9% versus S-QT 0% to 3.8%).

CONCLUSIONS

The main findings from this review report that more B-QT patients demonstrated postoperative rotatory instability than S-QT patients, and that there are no differences in graft rupture between the 2 graft choices. Although statistical conclusions may not be drawn because of heterogeneity in reporting, it appears that the B-QT group featured much wider major and minor complication profiles.

LEVEL OF EVIDENCE

IV, systematic review of level I-IV studies.

Truly Existing or Hyped up? Unravelling the Current Knowledge Regarding the Anatomy, Radiology, Histology and Biomechanics of the Enigmatic Anterolateral Ligament of the Knee Joint

Ever since its description, anterolateral ligament (ALL) of the knee joint remains as the hotspot of controversies. Though it has been described under various descriptions, the structure gained its limelight when it was christened as anterolateral ligament by Claes in 2013. The main reason for the controversies around it is the lack of concrete evidences regarding its attachments, morphology, biomechanical aspects and radiological appearance. Similarly the role of ALL in pivot shift phenomenon also remains as a point of debate. The advocates of ALL suggest that because of its ability to modulate internal rotation and attachment to the lateral meniscus, ALL contributes to the pivot shift phenomenon. Similarly, the orientation of ALL stands as the reason for varied documentation with respect to imaging techniques. With the growing body of evidence, it is imperative to fix our stand regarding the structure because, if found to be morphologically persistent, it can be used for concomitant anterolateral stabilization along with anterior cruciate ligament reinforcement surgeries. The present review tries to systematically review the anatomy, variations in classifications, descriptions, histology, radiology and biomechanical features of ALL. At the end of the review, we would like to find the answer for the question: Is ALL a distinct ligamentous structure located at the anterolateral aspect of the knee? What is the contribution of it to the tibial internal rotation stability?

Diagnosis and treatment of rotatory knee instability

BACKGROUND

Rotatory knee instability is an abnormal, complex three-dimensional motion that can involve pathology of the anteromedial, anterolateral, posteromedial, and posterolateral ligaments, bony alignment, and menisci. To understand the abnormal joint kinematics in rotatory knee instability, a review of the anatomical structures and their graded role in maintaining rotational stability, the importance of concomitant pathologies, as well as the different components of the knee rotation motion will be presented.

MAIN BODY

The most common instability pattern, anterolateral rotatory knee instability in an anterior cruciate ligament (ACL)-deficient patient, will be discussed in detail. Although intra-articular ACL reconstruction is the gold standard treatment for ACL injury in physically active patients, in some cases current techniques may fail to restore native knee rotatory stability. The wide range of diagnostic options for rotatory knee instability including manual testing, different imaging modalities, static and dynamic measurement, and navigation is outlined. As numerous techniques of extra-articular tenodesis procedures have been described, performed in conjunction with ACL reconstruction, to restore anterolateral knee rotatory stability, a few of these techniques will be described in detail, and discuss the literature concerning their outcome.

CONCLUSION

In summary, the essence of reducing anterolateral rotatory knee instability begins and ends with a well-done, anatomic ACL reconstruction, which may be performed with consideration of extra-articular tenodesis in a select group of patients.

Static Lateral Tibial Plateau Subluxation Predicts High-Grade Rotatory Knee Laxity in Anterior Cruciate Ligament-Deficient Knees

BACKGROUND

In anterior cruciate ligament-deficient (ACL-D) knees, injury pattern and bony morphologic features have been shown to influence both static anterior tibial subluxation relative to the femur and dynamic rotatory knee laxity. Therefore, the relationship between static anterior tibial subluxation and dynamic rotatory knee laxity was investigated.

PURPOSE

To determine whether static tibial subluxation as measured on magnetic resonance imaging (MRI) is associated with the grade of rotatory knee laxity in ACL-D knees.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Two-hundred fifty-eight knees underwent preoperative, image-guided assessment of lateral knee compartment translation during quantitative pivot shift (QPS). Subluxations of the medial and lateral tibial plateaus were measured on preoperative MRI in a subset of primary ACL-D knees meeting criteria for high-grade (QPS > 5.2 mm) and low-grade (QPS < 2.4 mm) rotatory laxity. Tibial subluxations on MRI were compared between patients with high- and low-grade rotatory laxity through use of pairwise t test and were analyzed via univariate and multivariate logistic regression. Significance was set at P < .05.

RESULTS

On MRI, greater anterior subluxation of the lateral tibial plateau was observed in patients with high-grade compared with low-grade rotatory knee laxity (4.5 mm vs 2.3 mm; P < .05). No similar relationship was observed for the medial tibial plateau (-0.9 mm vs -0.4 mm; P > .05). Univariate logistic regression demonstrated that static subluxation of the lateral tibial plateau was associated with high-grade rotatory knee laxity (odds ratio [OR], 1.2; P < .05). An optimal cutoff of 2.95 mm of static lateral tibial subluxation was associated with high-grade rotatory knee laxity (sensitivity, 75%; specificity, 63%). Lateral meniscal injury was the first variable entered into a multivariate regression analysis and proved to be most associated with high-grade rotatory knee laxity (OR, 6.8; P < .05). When lateral meniscal injury was excluded from multivariate regression analysis, static anterior subluxation of the lateral tibial plateau alone was associated with high-grade rotatory knee laxity (OR, 1.2; P < .05).

CONCLUSION

Data from this MRI study of two distinct rotatory knee laxity groups showed that static anterior subluxation of the lateral tibial plateau of 2.95 mm or greater was associated with high-grade rotatory knee laxity, and each millimeter increase of lateral tibial plateau subluxation was associated with a 1.2-fold odds of high-grade rotatory knee laxity. Anterior subluxation of the lateral tibial plateau on MRI was not independently associated with high-grade rotatory knee laxity in the presence of concomitant lateral meniscal injury. Static measurements made preoperatively may aid in predicting high-grade rotatory knee laxity and refining the indications for individualized knee surgery.

No correlation between femoral tunnel orientation and clinical outcome at long-term follow-up after non-anatomic anterior cruciate ligament reconstruction

PURPOSE

This study aimed to determine the influence of femoral tunnel orientation on long-term clinical outcome and osteoarthritis in patients undergoing ACL reconstruction and to test the reliability of the implemented radiographic measurement methods. It was hypothesized that a more horizontal femoral tunnel would correlate with superior clinical outcome.

METHODS

A cohort of 193 patients who underwent non-anatomic ACL reconstruction was examined. In this specific study, non-anatomic is defined by the surgeons' pursuit of optimal isometry, not to emulate the native ACL anatomy. At follow-up, the Lachman test, the KT-1000, the pivot-shift test, the one-leg-hop test and the IKDC-2000 were evaluated. Osteoarthritis was evaluated radiographically. Posteroanterior and lateral radiographs were used to determine the position of the femoral tunnel in the coronal and sagittal planes and the angle of the tunnel in the coronal plane. A method for determining femoral rotation on the lateral radiographs was developed and its reliability was evaluated. The femoral tunnel orientation was analyzed to examine its influence on clinical outcome and osteoarthritis.

RESULTS

A total of 101 patients were analyzed at a mean of 16.4 (± 1.3) years postoperatively. The reliability of the measurement methods was regarded as good to excellent (ICC 0.57-0.97). The mean coronal femoral tunnel angle was 9.6° (± 9.4°). The coronal femoral tunnel was positioned at a mean of 43% (± 3.5%) of the distance measured from lateral to medial. The mean sagittal femoral tunnel position, measured using the quadrant method, was 40% (± 6.4%) from posterior to anterior. No significant associations were found between tunnel orientation and the clinical outcome variables.

CONCLUSIONS

The orientation of the femoral tunnel did not predict the long-term subjective outcome, functional outcome or the development of osteoarthritis in patients undergoing non-anatomic ACL reconstruction. The method for determining femoral rotation on lateral radiographs was found to be reliable.

LEVEL OF EVIDENCE

Retrospective cohort study, level of evidence IV.

Can we predict the size of frequently used autografts in ACL reconstruction?

PURPOSE

This study presents a method to measure the size of quadriceps, patellar tendon and hamstring autografts using preoperative magnetic resonance imaging (MRI).

METHODS

Sixty-two subjects with a mean age of 25 ± 10 years who underwent ACL surgery between 2011 and 2014 were included. Patient anthropometric data were recorded for all subjects. During surgery, the respective autograft was harvested and measured using commercially available graft sizers. MRI measurements were performed by two raters, who were blinded to the intra-operative measurements.

RESULTS

The inter- and intra-rater reliability was ≥0.8 for all MRI measurements. The intra-class correlation coefficient between the MRI measurement of the graft and the actual size of the harvested graft was 0.639. There were significant correlations between quadriceps tendon thickness and height (r = 0.3, p < 0.03), weight (r = 0.3, p < 0.01), BMI (r = 0.3, p < 0.04) and gender (r = -0.4, p < 0.002) and patellar tendon thickness and height (r = 0.4, p < 0.01), weight (r = 0.3, p < 0.01) and gender (r = -0.4, p < 0.012).

CONCLUSION

Preoperative MRI measurements of quadriceps, patellar tendon and hamstring graft size are highly reliable with moderate-to-good accuracy. Significant correlations between patient anthropometric data and the thicknesses of the quadriceps and patellar tendons were observed. Obtaining this information can be useful for preoperative planning and to help counsel patients on appropriate graft choices prior to surgery.

LEVEL OF EVIDENCE

III.

Update on Anterior Cruciate Ligament Rupture and Care in the Female Athlete

As female athlete sports participation has continued to increase, the rate of anterior cruciate ligament (ACL) rupture in female athletes has also increased. Individualized, patient-specific treatment is crucial to achieving optimal outcomes; ACL reconstruction must accurately restore native ACL anatomy and address any concomitant injury to secondary stabilizers. Rehabilitation programs should target hip, core, and trunk neuromuscular control; allow adequate time for graft ligamentization; and address the psychosocial needs of the athlete.

Knee laxity modifications after ACL rupture and surgical intra- and extra-articular reconstructions: intra-operative measures in reconstructed and healthy knees

PURPOSE

Quantifying the effects of anterior cruciate ligament (ACL) deficiency on knee joint laxity is fundamental for understanding the outcomes of its reconstruction techniques. The general aim of this study was to determine intra-operatively the main modifications in knee laxity before and after standard isolated intra-articular and additional extra-articular anterolateral reinforcement. Our main hypothesis was that laxity abnormalities, particularly axial rotation, can still result from these ACL reconstruction techniques.

METHODS

Thirty-two patients with primary ACL deficiency were analysed by a navigation system immediately before and after each of the two reconstructions. Laxity measurements in terms of knee translations and rotations were taken during the anteroposterior drawer test, with internal-external rotation at 20° and 90° of flexion, and varus-valgus and pivot-shift tests. All these laxity measures were also taken originally from the contralateral healthy knee.

RESULTS

With respect to the contralateral healthy knee, in the ACL-deficient knee significantly increased laxity (expressed in %) was found in the medial compared with that of the lateral compartment, respectively, 115 and 68 % in the drawer test at 20° flexion, and 55 and 46 % at 90° flexion. In the medial compartment, a significant 35 % increment was also observed for the coupled tibial anteroposterior translation during axial knee rotation at 20° of flexion. After isolated intra-articular reconstruction, normal values of anteroposterior laxity were found restored in the pivot-shift and drawer tests in the lateral compartment, but not fully in the medial compartment. After the reinforcement, laxity in the medial compartment was also found restored in the axial rotation test at 20° flexion.

CONCLUSION

In ACL reconstruction, with respect to the contralateral knee, intra-articular plus additional anterolateral reinforcement procedures do not restore normal joint laxity. This combined procedure over-constrained the lateral compartment, while excessive laxity still persists at the medial one.

LEVEL OF EVIDENCE

III.

Anatomic Femoral and Tibial Tunnel Placement During Anterior Cruciate Ligament Reconstruction: Anteromedial Portal All-Inside and Outside-In Techniques

Tunnel malposition is one of the most common technical reasons for anterior cruciate ligament reconstruction failure. Small changes in tunnel placement can result in significant differences in outcome. More anatomic placement of the tunnels can lead to greater knee stability and a more accurate reproduction of native knee kinematics. This Technical Note describes 2 tibial tunnel-independent methods to obtain anatomic femoral tunnel placement. The all-inside anteromedial portal technique requires only minimal surgical incisions but allows precise femoral tunnel placement. However, hyperflexion of the knee is required, adequate surgical assistance is necessary, and this technique may be susceptible to graft-tunnel mismatch. The outside-in technique may be more beneficial in obese patients, skeletally immature patients, or revision cases. On the downside, it does require an additional 2-cm surgical incision. This article also provides surgical pearls to fine-tune tibial tunnel placement.

Correlation between a 2D simple image analysis method and 3D bony motion during the pivot shift test

BACKGROUND

The pivot shift test is the most specific clinical test to detect anterior cruciate ligament injury. The purpose of this study was to determine the correlation between the 2D simple image analysis method and the 3D bony motion of the knee during the pivot shift test and assess the intra- and inter-examiner agreements.

METHODS

Three orthopedic surgeons performed three trials of the standardized pivot shift test in seven knees. Two devices were used to measure motion of the lateral knee compartment simultaneously: 1) 2D simple image analysis method: translation was determined using a tablet computer with custom motion tracking software that quantified movement of three markers attached to skin over bony landmarks; 2) 3D bony motion: electromagnetic tracking system was used to measure movement of the same bony landmarks.

RESULTS

The 2D simple image analysis method demonstrated a good correlation with the 3D bony motion (Pearson correlation: 0.75, 0.76 and 0.79). The 3D bony translation increased by 2.7 to 3.5 times for every unit increase measured by the 2D simple image analysis method. The mean intra-class correlation coefficients for the three examiners were 0.6 and 0.75, respectively for 3D bony motion and 2D image analyses, while the inter-examiner agreement was 0.65 and 0.73, respectively.

CONCLUSIONS

The 2D simple image analysis method results are related to 3D bony motion of the lateral knee compartment, even with skin artifact present. This technique is a non-invasive and repeatable tool to quantify the motion of the lateral knee compartment during the pivot shift test.

Kinematic outcomes following ACL reconstruction

Anterior cruciate ligament (ACL) reconstruction aims to restore the translational and rotational motion to the knee joint that is lost after injury. However, despite technical advancements, clinical outcomes are less than ideal, particularly in return to previous activity level. A major issue is the inability to standardize treatment protocols due to variations in materials and approaches used to accomplish ACL reconstruction. These include surgical techniques such as the transtibial and anteromedial portal methods that are currently under use and the wide availability of graft types that will be used to reconstruct the ACL. In addition, concomitant soft tissue injuries to the menisci and capsule are frequently present after ACL injury and, if left unaddressed, can lead to persistent instability even after the ACL has been reconstructed. Advances in the field of biomechanics that help to objectively measure motion of the knee joint may provide more precise data than current subjective clinical measurements. These technologies include extra-articular motion capture systems that measure the movement of the tibia in relation to the femur. With data gathered from these devices, a threshold for satisfactory knee stability may be established in order to correctly identify a successful reconstruction following ACL injury.

Basic biomechanic principles of knee instability

Motion at the knee joint is a complex mechanical phenomenon. Stability is provided by a combination of static and dynamic structures that work in concert to prevent excessive movement or instability that is inherent in various knee injuries. The anterior cruciate ligament (ACL) is a main stabilizer of the knee, providing both translational and rotatory constraint. Despite the high volume of research directed at native ACL function, pathogenesis and surgical reconstruction of this structure, a gold standard for objective quantification of injury and subsequent repair, has not been demonstrated. Furthermore, recent studies have suggested that novel anatomic structures may play a significant role in knee stability. The use of biomechanical principles and testing techniques provides essential objective/quantitative information on the function of bone, ligaments, joint capsule, and other contributing soft tissues in response to various loading conditions. This review discusses the principles of biomechanics in relation to knee stability, with a focus on the objective quantification of knee stability, the individual contributions of specific knee structures to stability, and the most recent technological advances in the biomechanical evaluation of the knee joint.

There is no such thing like a single ACL injury: Profiles of ACL-injured patients

BACKGROUND

Current ACL registries rarely include non-operatively treated patients thus delivering an incomplete picture of the ACL-injured population. The aim of this study was to get an image of the population and treatment decision of an intrahospital registry. Our hypotheses were that patient-specific subtypes can be identified and that the percentage of operated patients differs between them.

MATERIAL AND METHODS

Three hundred and forty-six operated and non-operated patients were included from March 2011 to December 2013. Standardized questionnaires allowed for data collection on gender, age, sports practice and previous ACL injuries. Chi-square tests allowed to compare these parameters between genders and age groups. A cluster analysis was computed to determine profiles of patients with similar characteristics.

RESULTS

Three age groups were considered (I: ≤20; II: 21-35; III: ≥36 years). For males, the highest frequency of injuries was noted in group II with a greater proportion of injuries compared to females. In group III, more females were injured than males. Before injury, 54% patients were involved in competitive sports. Males were more likely to be injured in pivoting/contact sports before 35 and females during recreational skiing after 35. Twenty-one percent of the patients had had a previous ACL injury. The percentage of surgical treatment was superior to 80% in patients under 35 years involved in competitive sports, of 60-80% for those not involved in competitive sports and inferior to 60% for patients above 35 years.

DISCUSSION

Systematic data collection allowed to identify specific subtypes of ACL-injured patient according to gender, age, previous ACL injury and preinjury level of practice. The decision-making process for or against ACL reconstructions at time of presentation depended on these characteristics. Consideration of these parameters will serve as a basis for an individualized treatment approach and a better understanding of patients at risk for ACL injuries.

LEVEL OF EVIDENCE

III.