Anatomical "C"-shaped double-bundle versus single-bundle anterior cruciate ligament reconstruction in pre-adolescent children with open growth plates

Growth Disturbances Following Paediatric Anterior Cruciate Ligament Reconstruction: A Systematic Review

Growth disturbances after transphyseal paediatric anterior cruciate ligament (ACL) reconstruction have led to the development of physeal-sparing techniques. The aim of this study is to investigate growth disturbances following paediatric ACL reconstruction and identify associated risk factors. A systematic search on PubMed, Scopus and Web of Science databases was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify case series reporting paediatric ACL reconstructions. Of 518 articles, 78 met the inclusion criteria, and data related to growth disturbances and graft failures were extracted. A total of 2,693 paediatric ACL reconstructions resulted in 70 growth disturbances (2.6%): 17 were varus, 26 were valgus, 13 were shortening, 14 were lengthening and five patients had reduced tibial slope. Some patients showed deformities in more than one plane. Coronal plane deformities were seen more frequently with eccentric physeal arrest and lengthening with intraepiphyseal tunnelling. Shortening and reduced tibial slope were related to large central physeal arrest and anterior tibial physeal arrest, respectively. Sixty-two studies documented 166 graft failures in 2,120 reconstructions (7.8%). The extraphyseal technique was least likely to result in growth disturbances and graft failure. Paediatric ACL reconstruction is a safe and effective treatment of rupture. Growth disturbances are least likely following extraphyseal tunnelling, and those resulting from transphyseal techniques can be minimised by reducing drill size, drilling steep and avoiding the physeal periphery. The insertion of hardware, synthetic material, or a bone plug through the drilled physis should be avoided. There is a greater need for robust long-term data collection, such as national ligament registries, to standardise practice and evaluate the risk of growth disturbance and re-ruptures in this treatment.

A systematic review of transphyseal ACL reconstruction in children and adolescents: comparing the transtibial and independent femoral tunnel drilling techniques

PURPOSE

Aim of this systematic review was to analyze the outcome after transphyseal ACL reconstruction in children and adolescents regarding the femoral drilling technique.

METHODS

A systematic literature search was carried out in various databases on studies on transphyseal ACL reconstruction in children and adolescents. The literature search was limited to the last 20 years. Primary outcome criterion was the failure rate. Secondary outcome criteria were growth disturbances such as leg length discrepancies or deformities and clinical scores. The present study was registered prospectively ( www.crd.york.ac.uk/PROSPERO ; CRD42022345964).

RESULTS

A total of 22 retrospective or prospective case series (level 4 evidence) were identified that reported on transphyseal ACL reconstruction in children and adolescents. The overall failure/rupture rate after transphyseal ACL reconstruction was 11.0%. The overall ACL rupture rate of the contralateral side was 9.7%. No statistical significant difference in the failure rates between independent and transtibial drilling techniques could be detected ((p = 0.76/p = 0.28)). Furthermore no statistical significant differences in the rate of reported growth disturbances between independent and transtibial drilling techniques were shown (p = 0.15). The reported clinical scores at follow-up (mean follow-up 5.05 years) revealed good to very good results.

CONCLUSION

This systematic review demonstrates that children and adolescents have a relatively high failure rate after transpyseal ACL reconstruction without any statistically significant differences between independent or transtibial drilling techniques regarding reruptur rates or the rate of growth disturbances. The results of this systematic review warrant a comparison of both techniques for femoral tunnel drilling in a controlled randomized trial.

Return to Sports: A Risky Business? A Systematic Review with Meta-Analysis of Risk Factors for Graft Rupture Following ACL Reconstruction

BACKGROUND

The risk of sustaining a graft rupture after anterior cruciate ligament reconstruction (ACLR) is high. Contributing risk factors are, however, still not clearly identified.

OBJECTIVE

The aim of this systematic review was to identify and quantify risk factors for graft rupture after ACLR.

METHODS

A systematic review with meta-analysis (PROSPERO CRD42020140129) based on PRISMA guidelines was performed. MEDLINE, CINAHL and EMBASE were searched from inception to September 2021. Prospective and retrospective studies addressing risk factors for graft rupture after ACLR in males/females of all ages were considered. Meta-analyses using a random effect model (effect measure: odds ratio [OR] with 95% confidence interval [CI]) were performed. The GRADE tool was used to assess evidence quality.

RESULTS

Following full-text screening of 310 relevant papers, 117 were eventually included, incorporating up to 133,000 individuals in each meta-analysis. Higher Tegner activity level (≥ 7 vs < 7) at primary injury (OR 3.91, 95% CI 1.69-9.04), increased tibial slope (degrees) (OR 2.21, 95% CI 1.26-3.86), lower psychological readiness to return to sport (RTS) (OR 2.18, 95% CI 1.32-3.61), early surgery (< 12 vs ≥ 12 months) (OR 1.87, 95% CI 1.58-2.22), RTS (pre-injury level) (OR 1.87, 95% CI 1.21-2.91) and family history of ACL injury (OR 1.76, 95% CI 1.34-2.31) were all associated with increased odds of graft rupture. Higher age (OR 0.47, 95% CI 0.39-0.59), female sex (OR 0.88, 95% CI 0.79-0.98), fewer self-reported knee symptoms pre-reconstruction (OR 0.81, 95% CI 0.69-0.95) and concomitant cartilage injuries (OR 0.70, 95% CI 0.62-0.79) instead decreased the odds. Meta-analysis revealed no association between body mass index, smoking, joint laxity, RTS time, knee kinematics, muscle strength or hop performance and graft rupture.

CONCLUSION

Conspicuous risk factors for graft rupture were mainly sports and hereditary related. Few studies investigated function-related modifiable factors or included sports exposure data.

Assessment of Skeletal Maturity and Postoperative Growth Disturbance After Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: A Systematic Review

BACKGROUND

Growth disturbance is an uncommon but potentially serious complication after anterior cruciate ligament (ACL) reconstruction in skeletally immature patients.

PURPOSE

To describe how the pediatric ACL literature has assessed preoperative skeletal maturity and the amount of growth remaining and to comprehensively review the incidence, reporting, and monitoring of postoperative growth disturbance.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

This review included studies reporting original research of clinical outcomes of skeletally immature patients after ACL reconstruction. Patient characteristics, surgical techniques, preoperative assessments of skeletal maturity or growth remaining, and postoperative assessments of growth disturbances were extracted.

RESULTS

A total of 100 studies met inclusion criteria. All studies reported chronological age, and 28 studies (28%) assessed skeletal age. A total of 44 studies (44%) used Tanner staging, and 12 studies (12%) obtained standing hip-to-ankle radiographs preoperatively. In total, 42 patients (2.1%) demonstrated a leg length discrepancy (LLD) >10 mm postoperatively, including 9 patients (0.5%) with LLD >20 mm; furthermore, 11 patients (0.6%) with LLD underwent growth modulation. Shortening was the most common deformity overall, but overgrowth was reported more frequently in patients who had undergone all-epiphyseal techniques. Most LLDs involved the femur (83%). A total of 26 patients (1.3%) demonstrated a postoperative angular deformity ≥5°, and 9 of these patients underwent growth modulation. The most common deformities were femoral valgus (41%), tibial recurvatum (33%), and tibial varus (22%). Although standing hip-to-ankle radiographs were the most common radiographic assessment of growth disturbance, most studies inadequately reported the clinical and radiographic methods of assessment for growth disturbance. Additionally, only 35% of studies explicitly followed patients to skeletal maturity.

CONCLUSION

This systematic review described significant variability in the reporting and monitoring of growth-related complications after ACL reconstruction in skeletally immature patients. The incidence of LLD and angular deformity appeared to be low, but the quality of research was not comprehensive enough for accurate assessment.

REGISTRATION

CRD42019136059 (PROSPERO).

Systematic Review of Surgical Technique and Tunnel Target Points and Placement in Anatomical Single-Bundle ACL Reconstruction

The purpose of this systematic review was to reveal the trend in surgical technique and tunnel targets points and placement in anatomical single-bundle anterior cruciate ligament (ACL) reconstruction. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, data collection was performed. PubMed, EMBASE, and Cochran Review were searched using the terms "anterior cruciate ligament reconstruction," "anatomic or anatomical," and "single bundle." Studies were included when they reported clinical results, surgical technique, and/or tunnel placement evaluation. Laboratory studies, technical reports, case reports, and reviews were excluded from this study. From these full article reviews, graft selection, method of creating the femoral tunnel, and femoral and tibial tunnel target points and placement were evaluated. In the 79 studies included for data evaluation, the selected grafts were: bone patella tendon bone autograft (12%), and hamstring autograft (83%). The reported methods of creating the femoral tunnel were: transportal technique (54%), outside-in technique (15%), and transtibial technique (19%). In the 60 studies reporting tunnel target points, the target point was the center of the femoral footprint (60%), and the center of the anteromedial bundle footprint (22%). In the 23 studies evaluating tunnel placement, the femoral tunnel was placed in a shallow-deep direction (32.3%) and in a high-low direction (30.2%), and the tibial tunnel was placed from the anterior margin of the tibia (38.1%). The results of this systematic review revealed a trend in anatomical single-bundle ACL reconstruction favoring a hamstring tendon with a transportal technique, and a tunnel target point mainly at the center of the ACL footprint. The level of evidence stated is Systematic review of level-III studies.

Which Metrics Are Being Used to Evaluate Children and Adolescents After ACL Reconstruction? A Systematic Review

Purpose

To identify a comprehensive list of outcome measures previously used in the literature to evaluate clinical outcomes after reconstruction of the anterior cruciate ligament (ACL) in patients 18 years of age or younger.

Methods

A literature search was performed by querying MEDLINE, Embase and Cochrane computerized databases for relevant articles that reported clinical outcomes in pediatric patients undergoing ACL reconstruction. Studies that were nonclinical, that reported on patients older than 19 years, that were not available in English, or that included fewer than 10 patients were excluded. Outcome measures of all eligible studies were recorded.

Results

We identified 77 studies published between 1986 and 2018 in 20 peer-reviewed journals. The mean age of the patients was 13.9 years. The ACL rerupture rate was reported in 60% of studies; 32 studies (42%) reported a rate of return to preinjury activity or sports. The use of adult-validated patient-reported outcome measures were reported in 63 (82%) articles. The Lysholm (64%), International Knee Documentation Committee (IKDC) (56%) and Tegner (37%) scores were the most commonly reported. Two patient-reported outcome measures designed for pediatric patients (the Pedi-IKDC and Hospital for Special Surgery Pediatric Functional Activity Brief Scale (Pedi-FABS) were employed in 5 (6%) recent studies.

Conclusions

There is variability across studies in the metrics used to assess clinical outcomes following ACL reconstruction in children and adolescents. Validated pediatric-specific instruments were used infrequently.

Clinical Relevance

A large body of existing pediatric ACL-reconstruction literature relies on a variable set of outcome measures that have not been developed or validated for children and adolescents. More recently, contemporary studies have begun to employ pediatric- and adolescent-specific validated measures, yet their use remains uncommon.

Greater knee joint laxity remains in teenagers after anatomical double-bundle anterior cruciate ligament reconstruction compared to young adults

PURPOSE

There is paucity in studies regarding double-bundle anterior cruciate ligament reconstruction (DB-ACLR) in teenagers. The purpose of this study is to investigate clinical outcome after DB-ACLR and analyze whether any differences exist between teenagers and young adults.

METHODS

A retrospective study was performed between 2009 and 2017. Teenagers were defined as patients between 15 and 19 years and young adults between 20 and 25 years old. Isolated anterior cruciate ligament (ACL) injuries with DB-ACLR with minimum two-year follow up were included. Pre and post-operative Lysholm score, Tegner activity scale, KT-2000 arthrometer, manual pivot-shift grade, were assessed with post-operative one-leg hop test, isokinetic knee extensor strength test at 60°/sec, International Knee Documentation Committee Score (IKDC score), and re-injury rate.

RESULTS

One-hundred and thirty-one patients, 75 patients in the teenage group (Group A) and 56 patients in the young adult group (Group B), were enrolled. Lysholm score was significantly lower in Group A (89.6 ± 21.1) compared to Group B (95.9 ± 4.6) (p = 0.04). Side to side difference in KT-2000 arthrometer (2.3 ± 2.2 mm vs 1.0 ± 2.3 mm, Group A vs Group B, respectively, p < 0.01) and ratio of post-operative positive pivot shift was significantly greater in Group A (30.7%) compared to Group B (7.1%) (p < 0.01). No significant difference was seen in re-injury rate (n.s.).

CONCLUSION

Teenage patients have a greater tendency for residual knee joint laxity after DB-ACLR. Although teenagers and patients in the early twenties are close in age, characteristic in knee joint laxity may be different and, therefore, may require attention upon surgery and post-operative follow-up.

LEVEL OF EVIDENCE

III.

[Research progress of double-bundle anterior cruciate ligament reconstruction in adolescents]

OBJECTIVE

To review the advances in double-bundle anterior cruciate ligament (ACL) reconstruction in adolescents at home and abroad.

METHODS

Recent literature about double-bundle ACL reconstruction in adolescents at home and abroad was extensively consulted, and the relationship between bone canal and epiphyseal plate, clinical verification of surgical safety, and clinical effectiveness of double-bundle ACL reconstruction in adolescents were summarized and analyzed.

RESULTS

Double-bundle ACL reconstruction has certain advantages in clinical stability and re-rupture rate when compared with single-bundle ACL reconstruction in adolescents, and there is no significant difference in safety between them.

CONCLUSION

Double-bundle ACL reconstruction in adolescents can achieve lower re-rupture rate and better stability when compared with single-bundle reconstruction. However, the sample size of clinical research is too small, and the follow-up time is too short, so the effectiveness needs to be continuously observed.

Outcome Measures After ACL Injury in Pediatric Patients: A Scoping Review

Background

The incidence of anterior cruciate ligament (ACL) injuries in children is increasing. However, no standardized core set of outcome measures exists for evaluating pediatric ACL injuries.

Purpose

To perform a scoping review of the literature to identify patient-reported outcome measures (PROMs) and objective outcome measures used to evaluate pediatric patients after ACL injury and to classify these in accordance with the International Classification of Functioning, Disability, and Health (ICF) domains.

Study Design

Systematic review; Level of evidence, 4.

Methods

The literature was systematically searched with the PubMed, EMBASE, CINAHL, and PEDro databases. The inclusion criteria were Danish, Norwegian, Swedish, German, or English language; publication between 2010 and 2018; pediatric ACL injury (patients ≤15 years old); and outcome measures. The selected papers were screened for title, abstract, and full text in accordance with predefined inclusion and exclusion criteria.

Results

A total of 68 papers (4286 patients; mean ± SD age, 12.2 ± 2.3 years) were included. Nineteen PROMs and 11 objective outcome measures were identified. The most frequently reported PROMs were the International Knee Documentation Committee (IKDC) Subjective Knee Form (51% of studies), Lysholm scoring scale (46% of studies) and Tegner activity rating scale (37% of studies). Additionally, return to sport was reported in 41% of studies. The most frequent objective measures were knee laxity (76% of studies), growth disturbances (69% of studies), range of motion (41% of studies), and muscle strength (21% of studies). With respect to the ICF domains, the IKDC covered all 3 ICF health domains, the Lysholm score covered the Body Structure and Function and the Activity Limitation domains, while the Tegner score covered the Participation Restriction domain. Objectively measured knee joint laxity, range of motion, and muscle strength covered 1 domain (Body Structure and Function).

Conclusion

Pediatric patients with ACL injury were mainly evaluated subjectively with the IKDC and objectively by knee joint laxity. No consensus exists in the evaluation of children after ACL injury. The majority of applied outcome measures are developed for adults. To cover the ICF health domains, future research needs to consider reliable and valid outcome measures relevant for pediatric patients with ACL injury.

MRI study of the ligamentization of ACL grafts in children with open growth plates

INTRODUCTION

There is little published information on the ligamentization of pediatric anterior cruciate ligament (ACL) grafts. The aims of our study were to compare the MRI appearance of ACL grafts performed in a population with open growth plates to normal ACLs in adolescents and to determine whether the MRI signal in the grafts at 6 months could predict a retear. We hypothesized that ligamentization was a slow, gradual process.

MATERIAL AND METHODS

This was a prospective multicenter study of 100 ACL grafts (quadriceps tendon, hamstring tendon, fascia lata) in children 7 to 16 years of age. Of these, 65 intact grafts underwent one or more MRI examinations between 6 months and 2 years postoperative. MRI images were also analyzed in 7 patients who suffered a retear and in the intact ACL of 20 adolescents (15 to 18 years of age). The other 28 patients did not undergo an MRI during the postoperative phase. For each MRI, the signal-to-noise quotient (SNQ) was calculated in three different areas in the ACL (proximal, middle, distal) along with the Howell intra-articular and intra-tibial grades from I to IV. The Mantel-Haenszel Chi-square, Wilcoxon signed-rank test and Student's t-test were used to compare groups. The Lin concordance correlation coefficients were calculated for inter-rater consistency.

RESULTS

There was a difference in the SNQ between the three zones of a normal ACL. Most were Howell grade III (55% Howell III, 25% Howell II and 20% Howell I). For intact grafts, the SNQ improved significantly between 6 and 12 months and between 6 and 24 months. There was no difference in the SNQ between the three zones independent of the postoperative time point. The intra-articular Howell grade improved significantly between 6 and 24 months and between 12 and 24 months. The intra-tibial Howell grade improved significantly between 12 and 24 months. There were no significant differences between patients with intact grafts and those who suffered a retear. There were no differences between the various types of grafts used.

CONCLUSION

Normal ACLs in adolescents have inhomogeneous SNQ and Howell grades. The SNQ and Howell grades in ACL grafts are more homogeneous and continue to improve out to 2 years, but do not reach that of a normal ACL. The signal and appearance of an ACL graft and normal ACL are very different, and the MRI signal at 6 months postoperative is not predictive of retear.

LEVEL OF EVIDENCE

III, prospective study.

Stereophotogrammetric surface anatomy of the anterior cruciate ligament's tibial footprint: Precise osseous structure and distances to arthroscopically-relevant landmarks

BACKGROUND

While femoral tunnel malposition is widely recognized as the main technical error of failed anterior cruciate ligament (ACL) surgery, tibial tunnel malposition is likely underrecognized and underappreciated.

PURPOSE

To describe more precisely the qualitative and quantitative anatomy of the ACL's tibial attachment in vitro using widely available technology for stereophotogrammetric surface reconstruction, and to test its applicability in vivo.

METHODS

Stereophotogrammetric surface reconstruction was obtained from fourteen proximal tibias of cadaver donors. Measurements of areas and distances from the center of the ACL footprint and the footprint of the obtained bundles to selected arthroscopically-relevant anatomic landmarks were carried out using a three-dimensional design software program, and means and 95% confidence intervals were calculated for these measurements. Reference landmarks were tested in three-dimensional models obtained with arthroscopic videos.

MAIN FINDINGS

The osseous footprint of the ACL was described in detail, including its precise elevated limits, size, and shape, with its elevation pattern described as a quarter-turn-staircase-like ridge. Its internal indentations were related to inter-spaces identified as bundle divisions. Distances from the footprint center to arthroscopically relevant landmarks were obtained and compared to its internal structure, yielding a useful X-like landmark pointing to the most accurate placeholder for the ACL footprint's "anatomic" center. Certain structures and reference landmarks described were readily recognized in three-dimensional models from arthroscopic videos.

CONCLUSIONS

Stereophotogrammetric surface reconstruction is an accessible technique for the investigation of anatomic structures in vitro, offering a detailed three-dimensional depiction of the ACL's osseous footprint.

2018 International Olympic Committee Consensus Statement on Prevention, Diagnosis, and Management of Pediatric Anterior Cruciate Ligament Injuries

In October 2017, the International Olympic Committee hosted an international expert group of physical therapists and orthopaedic surgeons who specialize in treating and researching pediatric anterior cruciate ligament (ACL) injuries. The purpose of this meeting was to provide a comprehensive, evidence-informed summary to support the clinician and help children with ACL injury and their parents/guardians make the best possible decisions. Representatives from the following societies attended: American Orthopaedic Society for Sports Medicine; European Paediatric Orthopaedic Society; European Society for Sports Traumatology, Knee Surgery, and Arthroscopy; International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine; Pediatric Orthopaedic Society of North America; and Sociedad Latinoamericana de Artroscopia, Rodilla, y Deporte. Physical therapists and orthopaedic surgeons with clinical and research experience in the field and an ethics expert with substantial experience in the area of sports injuries also participated. This consensus statement addresses 6 fundamental clinical questions regarding the prevention, diagnosis, and management of pediatric ACL injuries. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision making with children and the potential long-term ramifications of the injury.

2018 International Olympic Committee consensus statement on prevention, diagnosis and management of paediatric anterior cruciate ligament (ACL) injuries

In October 2017, the International Olympic Committee hosted an international expert group of physiotherapists and orthopaedic surgeons who specialise in treating and researching paediatric ACL injuries. Representatives from the American Orthopaedic Society for Sports Medicine, European Paediatric Orthopaedic Society, European Society for Sports Traumatology, Knee Surgery & Arthroscopy, International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine, Pediatric Orthopaedic Society of North America and Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte attended. Physiotherapists and orthopaedic surgeons with clinical and research experience in the field, and an ethics expert with substantial experience in the area of sports injuries also participated. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision-making with children and the potential long-term ramifications of the injury. This consensus statement addresses six fundamental clinical questions regarding the prevention, diagnosis and management of paediatric ACL injuries. The aim of this consensus statement is to provide a comprehensive, evidence-informed summary to support the clinician, and help children with ACL injury and their parents/guardians make the best possible decisions.

2018 International Olympic Committee consensus statement on prevention, diagnosis and management of paediatric anterior cruciate ligament (ACL) injuries

In October 2017, the International Olympic Committee hosted an international expert group of physiotherapists and orthopaedic surgeons who specialise in treating and researching paediatric anterior cruciate ligament (ACL) injuries. Representatives from the American Orthopaedic Society for Sports Medicine, European Paediatric Orthopaedic Society, European Society for Sports Traumatology, Knee Surgery and Arthroscopy, International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine, Pediatric Orthopaedic Society of North America, and Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte attended. Physiotherapists and orthopaedic surgeons with clinical and research experience in the field, and an ethics expert with substantial experience in the area of sports injuries also participated. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision-making with children and the potential long-term ramifications of the injury. This consensus statement addresses six fundamental clinical questions regarding the prevention, diagnosis, and management of paediatric ACL injuries. The aim of this consensus statement is to provide a comprehensive, evidence-informed summary to support the clinician, and help children with ACL injury and their parents/guardians make the best possible decisions.

Posterior cruciate ligament reconstruction in skeletal immature children

PURPOSE

Rupture of the posterior cruciate ligament (PCL) is a rare knee injury in children with open growth plates. The follow-up results of six patients with open physes treated with PCL reconstruction are presented. The objective is to evaluate the clinical outcomes of PCL reconstruction for six skeletally immature patients.

METHODS

Between 2006 and 2010, six skeletally immature patients were treated with PCL reconstruction. At the time of surgery, the median age was 9 years (range 6-14). The median follow-up time after surgery was 50 months (range 41-90). Outcomes were evaluated by KOOS and Tegner scores, instrumented knee laxity, and radiologic long-axis leg length measurements.

RESULTS

The median KOOS score at follow-up was 88 (range 26-98). The median Tegner score was 6 (range 4-7). The median side-to-side difference in laxity according to KT-1000 was 2 mm (range 1-5) at 25° of flexion and 3 mm (range 3-6) at 70° of flexion. A median side-to-side difference in flexion of 8° was found. All but one patient had returned to playing sports at follow-up. One patient's index leg had a length discrepancy of 16 mm.

CONCLUSIONS

PCL reconstruction resulted in fair to good clinical outcomes for skeletally immature children. Clinically relevant leg length discrepancy was found in one of the six patients examined in this study.

LEVEL OF EVIDENCE

Level IV.

Anterolateral Ligament Expert Group consensus paper on the management of internal rotation and instability of the anterior cruciate ligament - deficient knee

Purpose of this paper is to provide an overview of the latest research on the anterolateral ligament (ALL) and present the consensus of the ALL Expert Group on the anatomy, radiographic landmarks, biomechanics, clinical and radiographic diagnosis, lesion classification, surgical technique and clinical outcomes. A consensus on controversial subjects surrounding the ALL and anterolateral knee instability has been established based on the opinion of experts, the latest publications on the subject and an exchange of experiences during the ALL Experts Meeting (November 2015, Lyon, France). The ALL is found deep to the iliotibial band. The femoral origin is just posterior and proximal to the lateral epicondyle; the tibial attachment is 21.6 mm posterior to Gerdy's tubercle and 4-10 mm below the tibial joint line. On a lateral radiographic view the femoral origin is located in the postero-inferior quadrant and the tibial attachment is close to the centre of the proximal tibial plateau. Favourable isometry of an ALL reconstruction is seen when the femoral position is proximal and posterior to the lateral epicondyle, with the ALL being tight upon extension and lax upon flexion. The ALL can be visualised on ultrasound, or on T2-weighted coronal MRI scans with proton density fat-suppressed evaluation. The ALL injury is associated with a Segond fracture, and often occurs in conjunction with acute anterior cruciate ligament (ACL) injury. Recognition and repair of the ALL lesions should be considered to improve the control of rotational stability provided by ACL reconstruction. For high-risk patients, a combined ACL and ALL reconstruction improves rotational control and reduces the rate of re-rupture, without increased postoperative complication rates compared to ACL-only reconstruction. In conclusion this paper provides a contemporary consensus on all studied features of the ALL. The findings warrant future research in order to further test these early observations, with the ultimate goal of improving the long-term outcomes of ACL-injured patients. Level of evidence Level V-Expert opinion.

The combination of tibial anterior translation and axial rotation into a single biomechanical factor improves the prediction of patient satisfaction over each factor alone in patients with ACL reconstructed knees

PURPOSE

The purpose of this study was to identify biomechanical factors, in both reconstructed and healthy knees, that correlate with patient satisfaction after ACL reconstruction.

METHODS

Seventeen patients who had undergone unilateral ACL reconstruction were reviewed 9 years post-op. Patients completed subjective questionnaires and underwent manual knee laxity testing (Lachman-Trillat, KT-1000, and pivot shift) and automated laxity testing. During automated testing, both legs were rotated into external rotation and then internal rotation until peak rotational torque reached 5.65 Nm. Load-deformation curves were generated from torque and rotation data. Features of the curves were extracted for analysis. Total leg rotation and anterior laxity during KT-1000 testing were combined into a single factor (Joint Play Envelope or JPE). Patients were divided into groups based on patient satisfaction scores (Group 1: Higher Satisfaction, Group 2: Lower Satisfaction, Group 3: Unsatisfied). Load-deformation curve features and manual laxity testing results were compared between groups 1 and 2 to determine which biomechanical factors could distinguish between the groups. Diagnostic screening values were calculated for KT-1000 testing, the pivot shift test, total leg rotation and JPE.

RESULTS

During manual testing, no significant differences in biomechanical factors were found when comparing reconstructed knees in group 1 and group 2. When comparing the reconstructed and healthy knees within group 2, the reconstructed knees had a significantly higher displacement during the KT-1000 manual maximum test (p < 0.002). When considering the reconstructed knees alone, neither the result of the pivot shift test nor KT-1000 testing could distinguish between group 1 and group 2. During automated testing, there were no significant differences between the groups when comparing the reconstructed lower limbs. The healthy lower limbs in group 2 had more maximum external rotation (p < 0.02) and decreased stiffness at maximum external rotation (p < 0.02) when compared to the healthy lower limbs in group 1. Total leg rotation was unable to distinguish between group 1 and group 2. JPE could distinguish between group 1 and group 2 when considering the reconstructed limb alone (p < 0.02). All four diagnostic screening values for JPE were equal or higher than in the other criteria. JPE also showed the most significant correlation with patient satisfaction.

CONCLUSIONS

Joint Play Envelope is an objective measure that demonstrated improved predictive value as compared to other tests when used as a measure of satisfaction in patients with ACL reconstructed knees.

Diagnostic findings caused by cutting of the iliotibial tract and anterolateral ligament in an ACL intact knee using a standardized and automated clinical knee examination

PURPOSE

The purpose of this study was to evaluate the separate contribution of the two definitions of the anterolateral ligament (ALL), the mid-third lateral capsular ligament (MTLCL) and deep capsule-osseous layer of the iliotibial tract (dcITT) in addition to the superficial iliotibial tract (sITT) to the control of tibial motion with respect to the femur during the application of force/torque seen during the three tests of the standard clinical knee examination (AP Lachman test, tibial axial rotation test and varus-valgus stress test).

METHODS

Six pelvis-to-toe cadaveric specimens were examined using an automated testing device that carried out the three components of the clinical knee examination. Internal/external rotation torque, anteroposterior load and adduction/abduction torque were applied, while torque/force and positional measurements were recorded. Sequential sectioning of the structures followed the same order for each knee, sITT, dcITT and MTLCL. Testing was repeated after release of each structure.

RESULTS

During the tibial axial rotation test, releasing the sITT caused an increase in internal rotation of 2.6° (1.4-4.1°, p < 0.0005), while release of the dcITT increased internal rotation an additional 0.8° (0.4-1.1°, p < 0.0015). Changes in secondary motions of the tibia after sITT release demonstrated an increase in anterior translation of 1.2 mm (0.6-2.0 mm, p < 0.0005) during internal rotation, while release of the dcITT increased the same motion an additional 0.4 mm (0.2-0.5 mm, p < 0.0005). During the AP Lachman test, release of the sITT caused the tibia to move more anteriorly by 0.7 mm (0.4-1.1 mm, p < 0.0005) and increased internal rotation by 2.7° (0.9-5.2°, p < 0.004). The additional release of the dcITT resulted in more anterior translation by 0.3 mm (0.1-0.4 mm, p < 0.002) and internal rotation by 0.9° (0.2-1.7°, p < 0.005). During the varus-valgus stress test, release of the sITT permitted 0.9° (0.4-1.4°, p < 0.0005) more adduction of the tibia, while the additional release of the dcITT significantly increased adduction by 0.4° (0.2°-0.5°, p < 0.001). Release of the MTLCL had a nominal but significant increase in internal rotation, 0.6° (0.1-1.1°, p < 0.0068) and external rotation, -0.1° (-0.1° to -0.2°, p < 0.0025) during the tibial axial rotation test, anterior translation of 0.2 mm (0.0-0.4 mm, p < 0.021) only during the AP Lachman test, and adduction rotation, 0.2° (0.0-0.3°, p < 0.034) only during the varus-valgus stress test.

CONCLUSION

The presence of increased adduction during an automated knee examination provides unique information identifying the release of the sITT, dcITT and the MTLCL in this cadaveric study. While their sequential release caused similar pattern changes in the three components of the automated knee examination, the extent of change due to release of the MTLCL was markedly less than after release of the dcITT which was markedly less than after release of the sITT.