Complications After Pediatric ACL Reconstruction: A Meta-analysis

Transphyseal arthroscopic anterior cruciate ligament reconstruction in children under 12 years

BACKGROUND

The incidence of anterior cruciate ligament (ACL) injuries in children is on the rise. Despite this trend, the optimal management of these injuries remains a matter of ongoing debate. In this light, our study seeks to assess the clinical, radiological, and functional outcomes of transphyseal ACL reconstruction in preadolescent patients in the medium-term.

METHODS

This prospective study included preadolescent patients aged up to 12 years who underwent ACL transphyseal reconstruction between 2010 and 2020 and had a minimum follow-up of 2 years. Clinical assessments encompassed joint stability and range of motion. Furthermore, leg length discrepancy (LLD) and femorotibial alignment were evaluated both clinically and radiologically using full-length lower limb standing radiographs. Pre- and postoperative functional outcomes were assessed using the International Knee Documentation Committee (IKDC) and Lysholm scales, and the return to normal sports activity was evaluated using the ACL-Return to Sport after Injury (ACL-RSI) scale. Complications and relevant follow-up data were also recorded. Statistical analyses were conducted to evaluate these outcomes.

RESULTS

A total of 35 preadolescent patients, consisting of 24 males and 11 females, with a mean age at surgery of 11.2 ± 0.7 years (8.7-12), were included in the study. The mean follow-up was 52.3 ± 20.7 months (24.1-95.9). No significant growth disturbances or clinically relevant LLD were evidenced. All patients demonstrated clinically stable knees with full range of motion at the 2-year follow-up. There were statistically significant improvements in pre- and postoperative IKDC (39.3 ± 13.5 vs. 99.7 ± 0.8, p < 0.005) and Lysholm scores (48.2 ± 15.1 vs. 99.6 ± 1.4, p < 0.005). All but two patients were able to return to their pre-injury level of sports activity, with a mean ACL-RSI score of 93.5 ± 1.3. The analysis revealed an 8.6% rerupture rate and an 11.4% rate of contralateral ACL injuries, with 5-year survival rates of 92.3% and 88.8%, respectively. Subgroup analyses based on age, gender, surgical delay, or associated meniscal lesions did not reveal any significant differences in functional outcomes. Additionally, there was no discernible relationship between age or timing of ACL reconstruction and the risk of meniscal injuries.

CONCLUSIONS

Our study reinforces the value of ACL reconstruction in skeletally immature preadolescent patients, with transphyseal technique proven to be a safe, effective, and technically simpler option, even for children under the age of 12. The findings indicate excellent functional outcomes, a high rate of successful return to sporting activities, and minimal to no incidence of growth-related complications in the medium-term.

LEVEL OF EVIDENCE

Level II, prospective comparative cohort study, before and after intervention.

Risk Factors for the Development of Arthrofibrosis After Anterior Cruciate Ligament Reconstruction in Children and Adolescents

BACKGROUND

Arthrofibrosis is a fibrotic joint disorder resulting in restricted joint motion and pain. Risk factors associated with the development of postoperative arthrofibrosis include female sex, type of graft, and quicker time to reconstruction. These patients have typically benefitted from manipulation under anesthesia or arthroscopic lysis of adhesions. The purpose of this study was to retrospectively review the rate of arthrofibrosis in children and adolescents who previously underwent anterior cruciate ligament (ACL) reconstruction.

MATERIALS AND METHODS

This was a retrospective chart review examining patients 18 years or younger who underwent ACL reconstruction between 2013 and 2023. Data collected included age, body mass index, reconstruction technique, concomitant meniscal or ligamentous pathology, and need for revision surgery for arthroscopic lysis of adhesions vs manipulation under anesthesia.

RESULTS

A total of 461 patients 18 years or younger who underwent ACL reconstruction were included in this study. Eighteen (3.90%) patients required reoperation for the development of arthrofibrosis. Skeletally immature patients were found to have a statistically significant lower rate of arthrofibrosis compared with skeletally mature patients (0% vs 4.80%; P=.0184). Patients with a higher weight and body mass index had an increased rate of arthrofibrosis (P=.0485 and P=.0410, respectively). Graft type did not have a significant impact on arthrofibrosis rates. There were no significant findings in terms of concomitant injuries and rate of arthrofibrosis.

CONCLUSION

Arthrofibrosis developed in 3.90% of patients after ACL reconstruction. Skeletal immaturity may be protective against the development of arthrofibrosis. No association was found between graft type or concomitant knee pathology and arthrofibrosis. [Orthopedics. 2024;47(4):e161-e166.].

Management of Anterior Cruciate Ligament Tears in Skeletally Immature Patients

PURPOSE OF REVIEW

Anterior cruciate ligament (ALC) tears are increasingly common in skeletally immature patients, as more children and adolescents participate in intensive sports training and specialization at increasingly younger ages. These injuries were historically treated nonoperatively, given concerns for physeal damage and subsequent growth disturbances after traditional ACL reconstruction techniques. However, there is now sufficient data to suggest superior outcomes with operative treatment, specifically with physeal-sparing and physeal-respecting techniques. This article reviews considerations of skeletal maturity in patients with ACL tears, then discusses surgical techniques, with a focus on their unique indications and outcomes. Additional surgical adjuncts and components of postoperative rehabilitation, which may reduce retear rates, are also considered.

RECENT FINDINGS

Current research shows favorable patient-reported outcomes and high return-to-sport rates after ACL reconstruction in skeletally immature patients. Graft rupture (ACL retear) rates are low, but notably higher than in most adult populations. Historically, there has been insufficient research to comprehensively compare reconstruction techniques used in this patient population. However, thoughtful systematic reviews and multicenter prospective studies are emerging to address this deficit. Also, more recent data suggests the addition of lateral extra-articular procedures and stringent return-to-sports testing may lower retear rates. Physeal-sparing and physeal-respecting ACL reconstructions result in stabilization of the knee, while respecting the growth remaining in children or skeletally immature adolescents. Future research will be essential to compare these techniques, given that more than one may be appropriate for patients of a specific age and skeletal maturity.

Quadriceps Tendon Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: 3-Year Clinical and Patient-Reported Outcomes

BACKGROUND

The rate of anterior cruciate ligament (ACL) rupture in active, skeletally immature patients is increasing. Although hamstring tendon autograft (HTA) was previously deemed the gold standard, recent studies have shown HTA to have a high failure rate in this high-risk population of young competitive athletes, and quadriceps tendon autograft (QTA) has yielded excellent preliminary outcomes in some studies examining this population.

PURPOSE

To evaluate 3-year clinical and patient-reported functional outcomes of primary ACL reconstruction (ACLR) with soft tissue QTA in skeletally immature patients.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Skeletally immature patients who underwent ACLR with a full-thickness soft tissue QTA were included. Preoperative patient and surgical data were collected. The ACLR technique was selected predicated upon skeletal age and included all-epiphyseal and complete transphyseal techniques. Patients were followed for a minimum of 2 years with successive clinical visits or were contacted via telephone. Patients who did not have minimum 2-year follow-up after 3 contact attempts via telephone were excluded. Information regarding return to sports (RTS) and concomitant or subsequent surgical procedures was collected. Pediatric International Knee Documentation Committee (Pedi-IKDC), Hospital for Special Surgery Functional Activity Brief Scale (HSS Pedi-FABS), and Single Assessment Numeric Evaluation (SANE) scores were collected.

RESULTS

Of 85 adolescent patients aged 11.1 to 17.6 years (mean age, 14.1 ± 1.2 years), 2 patients were determined to be lost to follow-up after 3 failed contact attempts. Of the patients included in this study (N = 83), 26 patients (31%) underwent all-epiphyseal and 57 patients (69%) underwent complete transphyseal ACLR. Additionally, 48 patients (58%) underwent concomitant lateral extra-articular tenodesis using the iliotibial band with a modified Lemaire technique. The mean follow-up time was 3.7 ± 1.2 years (range, 2-7 years). Twenty (24%) patients had subsequent surgical procedures, of which 3 (4%) were due to graft failures. At a mean 3-year follow-up, the mean Pedi-IKDC, HSS Pedi-FABS, and SANE scores were 90, 23, and 94 respectively; the RTS rate was 100%; and the rate of RTS at the previous level of performance was 93%.

CONCLUSION

Use of a soft tissue QTA for ALCR in a high-risk skeletally immature population of athletes resulted in excellent postoperative outcomes with low rates of graft failure and high return to sport rates.

Association of Spanish as a Primary Language With Retear Rates After Pediatric ACL Reconstruction

Background

Anterior cruciate ligament (ACL) injuries are one of the most common knee injuries in pediatric patients in the United States. The patient's primary spoken language may affect outcomes after ACL reconstruction (ACLR).

Purpose/Hypothesis

The purpose of this study was to identify differences in ACLR outcomes between patients whose primary, preferred spoken language was either English or Spanish. It was hypothesized that there would be a difference in retear rates between patients preferring English versus Spanish.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective cohort study was performed on pediatric and adolescent patients who underwent ACLR at a single institution. Patients were divided into 2 cohorts based on their preferred spoken language: English or Spanish. All patients underwent either hamstring tendon or bone-patellar tendon-bone autograft ACLR performed by the same surgeon with the same postoperative rehabilitation protocols. Linear regression, chi-square tests, and multivariate logistic regression were used to determine if outcomes, graft tear, revision surgery, and contralateral injury differed between groups.

Results

A total of 68 patients were identified: 33 patients whose preferred language was English and 35 patients whose preferred language was Spanish. The overall mean age of the patients was 16.4 ± 1.4 years (range, 13.2-20.5 years), and the mean follow-up time was 3.26 ± 1.98 years (range, 0.53-8.13 years). Patients who preferred Spanish were more likely than those who preferred English to experience graft tears requiring revision surgery after ACLR (P = .02; odds ratio [OR] = 5.81; adjusted OR = 1.94), at a tear rate of 14.3%.

Conclusion

Patients who preferred to speak Spanish experienced higher graft tear rates when compared with patients who preferred speaking English, even after adjusting for sex, sport played, graft type, type of insurance, and time to surgery.

Transphyseal ACL reconstruction and tenodesis in skeletally immature patients demonstrates encouraging clinical scores, without growth disturbance, excessive laxity or re-injury

Purpose

Paediatric patients demonstrate high re-rupture rates after anterior cruciate ligament reconstruction (ACLR), with numerous surgical techniques proposed to deal with this challenging cohort. This study investigated the early clinical outcomes, complications, return to sport (RTS) and re-rupture rates up until 2-years post-surgery in paediatric patients presenting with open growth plates undergoing transphyseal ACLR that was combined with an extra-articular tenodesis (LET).

Methods

Between October 2017 and September 2020, 20 skeletally immature patients were consecutively recruited and underwent transphyseal ACLR and LET. Patient reported outcome measures (PROMs), KT-1000 laxity, knee range of motion (ROM), maximal isokinetic knee torque and a 3-hop battery were assessed at 6-, 12- and 24-months. Limb Symmetry Indices (LSIs), RTS rates, complications, re-ruptures and re-operations were reviewed.

Results

All PROMs improved (p < 0.05). No change (p = 0.903) in laxity between limbs was seen, while 18 patients (90%) demonstrated normal (<3 mm) or near normal (3-5 mm) laxity differences. Peak knee flexion ROM improved over time (p = 0.028), while LSIs for knee extensor strength (p < 0.001), the single (p = 0.002) and triple crossover (p = 0.038) hop tests improved. At 24 months, 18 patients (90%) were participating in their pre-injury pivoting sport activities. No complications, growth disturbances, re-injuries or subsequent surgeries were observed.

Conclusions

Transphyseal ACLR combined with LET, undertaken in skeletally immature paediatric patients, demonstrated high scoring PROMs, physical performance and RTS overall, without evidence of growth disturbance or excessive graft laxity. No re-injuries have been observed at this time with ongoing review required in this high-risk cohort.

Pediatric ACL Reconstruction in Children-An Evaluation of the Transphyseal Technique's Efficacy and Safety

INTRODUCTION

Injuries of the anterior cruciate ligament (ACL) are commonly found in the general population, both among adult and pediatric patients, and their incidence has been increasing in recent years. Most of the late literature agrees that surgical reconstruction of the ACL is effective in improving long-term outcomes in pediatric patients, while others in the past have pleaded for non-surgical management.

PURPOSE/HYPOTHESIS

Our study aims to verify if ACL reconstruction (ACLR) using transphyseal technique in skeletally immature patients will provide angular deviations or growth restrictions.

STUDY DESIGN

Retrospective cohort study; Level of evidence 4.

METHODS

We perfomed a retrospective study to verify if transphyseal ACLR in children with less than or equal to 2 years of remaining growth leads to either limb length discrepancies or axis deviations.

RESULTS

Most patients who were treated using transphyseal technique showed significant improvements in their functional scores. There were statistically significant differences in lateral distal femoral angles (LDFA) and medial proximal tibial angles (MPTA), with no clinical impact. There was no significant limb length discrepancy (LLD) during the 2-year follow-up.

CONCLUSIONS

Transphyseal ACLR is safe among children who have less than or equal to 2 years of remaining growth and brings no risk of axis deviations or limb length discrepancy.

Postoperative Strength Differences at Short-Term Follow-Up Vary Based on Autograft Harvest Site After Adolescent Transphyseal Anterior Cruciate Ligament Reconstruction

PURPOSE

To compare the clinical and patient-reported outcomes of adolescent patients who underwent anterior cruciate ligament reconstruction (ACLR) with quadriceps tendon (QT) versus hamstring tendon (HT) autograft.

METHODS

This was a retrospective cohort study of adolescent patients aged 18 years or younger treated at a single tertiary care children's hospital who underwent primary transphyseal ACLR using QT or HT between January 2018 and December 2019. All patients had minimum 6-month follow-up. Outcomes included isokinetic strength testing, postoperative Patient-Reported Outcomes Measurement Information System and International Knee Documentation Committee scores, and complications; these were compared between the QT and HT cohorts.

RESULTS

A total of 84 patients (44 HT and 40 QT patients) were included. The QT cohort had a higher proportion of male patients (62.5% vs 34.1%, P = .01). At 3 months, HT patients had a lower hamstring-quadriceps (H/Q) strength ratio (60.7 ± 11.0 vs 79.5 ± 18.6, P < .01) and lower Limb Symmetry Index in flexion (85.6 ± 16.1 vs 95.5 ± 15.7, P = .01) whereas QT patients had a lower Limb Symmetry Index in extension (67.3 ± 9.5 vs 77.4 ± 10.7, P < .01). The H/Q ratio at 6 months was lower in HT patients (59.4 ± 11.5 vs 66.2 ± 7.5, P < .01). Patient-Reported Outcomes Measurement Information System and International Knee Documentation Committee scores were not different at 3 months or latest follow-up. QT patients had more wound issues (20.0% vs 2.3%, P = .01). Patients receiving HT autograft had more ipsilateral knee injuries (18.2% vs 2.5%, P = .03), but there was no difference in graft failure for ACLR using HT versus QT (9.1% vs 2.5%, P = .36).

CONCLUSIONS

There were no differences in patient-reported outcome measures between patients receiving QT autografts and those receiving HT autografts. Patients with QT grafts had more postoperative wound issues but a lower rate of ipsilateral knee complications (graft failure or meniscal tear). Differences in quadriceps and hamstring strength postoperatively compared with the contralateral limb were observed for adolescent ACLR patients receiving QT and HT autografts, respectively. This contributed to higher H/Q ratios seen at 3 and 6 months postoperatively for patients receiving QT autografts.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic study.

Quadriceps tendon autograft is promising with lower graft rupture rates and better functional Lysholm scores than hamstring tendon autograft in pediatric ACL reconstruction. A systematic review and meta-analysis

Purpose

Graft rupture is the most prevalent complication following pediatric anterior cruciate ligament reconstruction (ACLR). The hamstring tendon (HT) autograft is frequently employed, while the quadriceps tendon (QT) autograft has garnered increased attention recently. This study aims to perform a systematic review to assess the complication rates and functional outcomes associated with these two widely used autografts in skeletally immature patients - comparing HT versus QT autografts.

Research question

Is QT autograft better than HT autograft for ACLR in skeletally immature cohorts?

Methodology

Three electronic databases (PubMed/Medline, Scopus, and Ovid) were comprehensively searched to identify pertinent articles reporting the outcomes of HT and QT autografts in pediatric ACLR with a minimum 2-year follow-up. Data on the outcome parameters, such as graft rupture rates, contralateral ACL injury rates, functional outcomes, and growth disturbances rates, were extracted. Meta-analysis was performed using OpenMeta Analyst software.

Results

Twelve studies were included for meta-analysis (pooled analysis) with 659 patients (QT: 205; HT: 454). The analysis showed that QT autografts had a significantly lesser graft rupture rate than HT autografts (3.5 % [95 % CI 0.2, 6.8] and 12.4 % [95 % CI 6.1, 18.7] respectively, p < 0.001). The graft rupture rates between QT with bone and without bone block showed no statistically significant difference (4.6 % [95 % CI 0.8, 1.0] and 3.5 % [95 % CI 2.0, 8.9] respectively, p = 0.181). The overall contralateral ACL injury rate was 10.2 %, and the subgroup analysis revealed no statistically significant difference between the QT and HT groups (p = 0.7). Regarding functional outcome scores at the final follow-up, the mean Lysholm score demonstrated a significant increase in the QT group compared to the HT group (p < 0.001). There were no significant differences between the two groups concerning growth disturbances at the final follow-up. Return to sports (RTS) varied between 6 and 13.5 months after surgery.

Conclusion

QT autografts demonstrate encouraging outcomes, showcasing lower graft rupture rates, better functional outcomes, and comparable contralateral ACL injury rates and growth disturbances relative to the commonly used HT autograft in skeletally immature patients undergoing ACLR.

Functional Rehabilitation of Anterior Cruciate Ligament Tear in the Pediatric Population: A Comprehensive Review

Pediatric sports injuries are a growing concern due to increased youth participation in sports. Effective rehabilitation strategies are essential for ensuring optimal recovery, restoring knee function, and preventing long-term consequences. This research aims to explore and evaluate various functional rehabilitation approaches tailored to pediatric anterior cruciate ligament (ACL) tear injuries. Functional rehabilitation of ACL tears in pediatric sports injuries is an important area of research due to the unique considerations and challenges that arise when treating ACL injuries in young athletes. Over the last 20 years, there has been a well-documented uptick in ACL injuries among pediatric populations. This rise can be attributed to the growing involvement of the younger population in competitive sports, as well as heightened awareness regarding sports-linked injuries. This study highlights the importance of early surgical reconstruction in children to enable a quick return to sports and prevent long-term cartilage and meniscal damage resulting from instability. The use of physeal-sparing ACL reconstruction techniques, particularly hamstring autografts, is recommended for favorable clinical outcomes while minimizing growth disturbances. This study offers valuable insights for healthcare professionals and researchers, serving as a reference to guide optimal approaches in managing pediatric ACL injuries and achieving successful results in this field.

The Risk of Growth Disturbance Is Low After Pediatric Anterior Cruciate Ligament Reconstruction With a Femoral Growth Plate Sparing Technique

Purpose

To evaluate radiological tibial and femoral length and axis growth disturbances, as well as clinical outcome in skeletal immature anterior cruciate ligament reconstruction (ACLR) patients treated with a femoral growth plate-sparing ACLR technique.

Methods

Skeletally immature patients who underwent operation between 2013 to 2019 with ALCR using the femoral growth plate-sparing technique were investigated with follow-up after growth plate closure. The inclusion criteria were isolated ACL rupture in patients with open physis in the distal femur and proximal tibia seen at plain radiography. The minimum follow-up time was 29 months. Patients were evaluated with full extremity radiographs measuring limb length discrepancy and coronal knee alignment compared to contralateral leg, as well as clinical evaluation with Rolimeter measurements and the Knee Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee subjective knee form (IKDC), and Tegner Activity Scale scores.

Results

Sixty-five patients were examined with radiography, and 52 patients were assessed with clinical examination. The mean follow-up time was 68 (range, 29-148) months. No limb-length discrepancy (-0.65 mm [confidence interval {CI}, -2.21 to 0.92]) or angular deformity at tibia (-0.25° [CI, -0.78° to 0.28°]) was found. There was a small but statistically significant different angular deformity at the distal femur compared to the contralateral leg (-1.51° [CI, -2.31 to -0.72]) at follow-up. The side-to-side difference in knee laxity at follow-up was 2.4 mm. At follow-up the KOOS Sport, KOOS Quality of Life (QoL), IKDC, and Tegner scores were 80, 75, 86, and 5, respectively. Sixty-seven percent of the patients met the Patient Acceptable Symptom State, and 52% reported results exceeding the KOOS Sport MCID Level and 69% the KOOS QoL level.

Conclusions

Femoral physis-sparing ALCR is associated with a low risk of alignment and length disturbances. The technique provides otherwise good subjective clinical outcome and knee stability.

Level of Evidence

Level IV, therapeutic case series.

Differences in the microstructural and mechanical qualities of semitendinosus tendon grafts between skeletally immature and mature patients in anterior cruciate ligament reconstruction

BACKGROUND

This study aimed to investigate the microstructural and mechanical properties of semitendinosus tendon graft tissues during anterior cruciate ligament reconstruction and the clinical outcomes in skeletally immature and mature patients.

METHODS

Twenty-two patients who underwent primary anterior cruciate ligament reconstruction using a hamstring tendon graft were analyzed and divided into skeletally immature (n = 7) and mature groups (n = 15) based on magnetic resonance imaging findings of the epiphyseal plate of the distal femur. Tissue samples were collected from the mid-portion of the semitendinosus tendon. The collagen fibril diameter, maximum stress, and strain at maximum stress point in the semitendinosus tendon tissues were calculated for comparison of the microstructural and mechanical properties between the two groups. Postoperative outcomes were also assessed between the two groups.

RESULTS

The mean and 60th and 80th percentiles of fibril diameters in the skeletally immature group were significantly smaller than those in the mature group (65.9 ± 13.0, 73.5 ± 19.3, and 91.3 ± 27.4 nm in the skeletally immature group; and 90.3 ± 14.7, 94.0 ± 18.4, and 125.3 ± 19.9 nm in the skeletally immature group; p = 0.001, 0.024, and 0.004, respectively). Additionally, the strain at maximum stress was higher in the skeletally immature group (237.2 ± 102.4% vs. 121.5 ± 51.9%, p = 0.024). However, there was no difference in maximum stress between the skeletally immature and mature groups (19.9 ± 14.3 MPa vs. 24.5 ± 23.4 MPa, p = 0.578). Strain was negatively correlated with the mean fibril diameter and the 60th and 80th percentiles of fibril diameters, whereas stress was positively correlated with the mean fibril diameter. The skeletally immature group had a higher pivot shift test-positive rate than the mature group at the last follow-up (p = 0.023).

CONCLUSION

Semitendinosus tendon graft tissues differed microstructurally and mechanically between skeletally immature and mature patients.

LEVEL OF EVIDENCE

Level Ⅳ.

Revision Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients

Revision anterior cruciate ligament (ACL) reconstruction in the skeletally immature patient is a challenging procedure for pediatric patients with recurrent instability after primary ACL reconstruction. The pediatric population presents unique technical challenges and complications secondary to open physes compared with the adult population. Complications can include growth disturbances, recurrent graft failure, instability, and secondary chondral and/or meniscal injury. Moreover, identifying the etiology of graft failure is critical for a successful revision. Patients should undergo a complete history and physical examination with a focus on patient physiologic age, physeal status, mechanical axis, tibial slope, collagen status, injury mechanism, concomitant injuries, and previous surgical procedures. The surgeon must be adept at reconstruction with various grafts as well as socket or tunnel preparation and fixation, including over-the-top, all-epiphyseal, transphyseal, extra-articular augmentation, and staging approaches. Reported rates of return to sport are lower than those of primary reconstruction, with higher rates of cartilage and meniscal degeneration. Future research should focus on optimizing surgical outcomes and graft survivorship after primary ACL reconstruction with minimized trauma to the physis.

Analysis of Growth After Transphyseal Anterior Cruciate Ligament Reconstruction in Children

BACKGROUND

Pediatric transphyseal anterior cruciate ligament reconstruction (ACLR) bears several advantages and is widely used. The main concern is the risk of growth disturbance. Our purpose was to investigate the incidence and risk factors of growth disturbance in skeletally immature patients who underwent transphyseal ACLR. We hypothesized that this procedure would generate neither clinically relevant limb length discrepancy (LLD) nor axis deviation.

METHODS

This prospective, consecutive, single-center series included skeletally immature patients who underwent primary transphyseal ACLR using semitendinosus tendon autograft, with a 2-year follow-up bone length standing radiograph of both lower limbs from pelvis to ankle in anterior posterior view. Lower limb length, mechanical axis deviation (MAD), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) were measured. The definition of postoperative growth disturbance was defined as ≥10 mm for LLD or ≥3 degrees for axis deviation in comparison to the contralateral lower limb. Predictive variables included age at surgery, gender, side, and diameter of bone tunnels. Student or Mann-Whitney test was used for numerical variables, and Chi-square test or Fisher exact test was used for categorical variables. P values <0.05 were considered statistically significant.

RESULTS

Fifty consecutively treated patients were included. Forty-seven patients (31 boys, 16 girls) with a mean age of 13.2 years (range, 9 to 16) at the time of surgery were available for analysis. Six patients had an LLD of at least 10 mm. Twenty-five patients had a difference in MPTA of a least 3 degrees (range, 5 to 8). Sixteen patients had a difference in LDFA of a least 3 degrees (range, 4 to 9). No patients presented with a clinical deformity or related symptoms. Regarding coronal alignment, there was no statistical difference in mechanical axis deviation, LDFA, or MPTA. Gender, side, age, and bone tunnel diameter did not influence growth disturbance.

CONCLUSIONS

Transphyseal pediatric ACLR generated a high rate of growth disturbances (leg length discrepancy and axis deviation) although none clinically relevant. Mild proximal tibial axis deviation in patients operated on near skeletal maturity should be further investigated.

LEVEL OF EVIDENCE

Level III.

STUDY DESIGN

Case-control study.

Intrarater and Interrater Reliability of Radiographic Characteristics in Skeletally Immature Patients With Anterior Cruciate Ligament Tears: A PLUTO Study Group Reliability Study

BACKGROUND

Radiographic measurements of limb alignment in skeletally immature patients with anterior cruciate ligament (ACL) tears are frequently used for surgical decision-making, preoperative planning, and postoperative monitoring of skeletal growth. However, the interrater and intrarater reliability of these radiographic characteristics in this patient population is not well documented.

HYPOTHESIS

Excellent reliability across 4 raters will be demonstrated for all digital measures of length, coronal plane joint orientation angles, mechanical axis, and tibial slope in skeletally immature patients with ACL tears.

STUDY DESIGN

Cohort study (diagnosis).

METHODS

Three fellowship-trained orthopaedic surgeons and 1 medical student performed 2 rounds of radiographic measurements on digital imaging (lateral knee radiographs and long-leg radiographs) of skeletally immature patients with ACL tears. Intrarater and interrater reliability for continuous radiographic measurements was assessed with intraclass correlation coefficients (ICCs) across 4 raters with 95% CIs for affected and unaffected side measurements. Interrater reliability analysis used an ICC (2, 4) structure and intrarater reliability analysis used an ICC (2, 1) structure. A weighted kappa coefficient was calculated for ordinal variables along with 95% CIs for both interrater and intrarater reliability. Agreement statistic interpretations are based on scales described by Fleiss, and Cicchetti and Sparrow: <0.40, poor; 0.40 to 0.59, fair; 0.60 to 0.74, good; and >0.74, excellent.

RESULTS

Radiographs from a convenience sample of 43 patients were included. Intrarater reliability was excellent for nearly all measurements and raters. Interrater reliability was also excellent for nearly all reads for all measurements.

CONCLUSION

Radiographic reliability of long-leg radiographs and lateral knee x-rays in skeletally immature children with ACL tears is excellent across nearly all measures and raters and can be obtained and interpreted as reliable and reproducible means to measure limb length and alignment.

LEVEL OF EVIDENCE

Level III.

Size and Morphology of the Anterior and Posterior Cruciate Ligaments at Different Pediatric Age Intervals: An MRI Analysis

Background

The incidence of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears in children and adolescents has increased over the past decade, with increasing numbers of ACL and PCL reconstructions in this patient population.

Purpose

To evaluate the size and morphology of both the ACL and the PCL by magnetic resonance imaging (MRI) in different pediatric age groups.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

MRI examinations of 127 knees (67 female, 60 male; aged 0-18 years) were analyzed retrospectively. The cohort was split into 6 age subgroups, 1 subgroup for every 3 years (minimum 8 patients per subgroup). The following parameters were measured by 2 independent raters at 2 different time points: ACL length, anteroposterior and mediolateral ACL width, sagittal and coronal ACL inclination, inclination of the intercondylar notch, bicondylar width, notch width, coronal ACL and PCL width, PCL length, and sagittal width of the lateral femoral condyle. The following indices, areas, and volumes were calculated: sagittal width of the lateral femoral condyle/PCL length, ACL area and volume, notch width index, ACL width/notch width, PCL width/notch width, ACL width/bicondylar width, and PCL width/bicondylar width. A correlation analysis was performed for patient age, height, weight, and body mass index (BMI).

Results

ACL length was between 18 and 37 mm, and ACL width was between 4 and 6 mm. PCL length ranged between 27 and 43 mm, while PCL width was between 7 and 9 mm. Growth of the cruciate ligaments was the most pronounced between the ages of 4 and 12 years. Correlations with size and weight were strong, while BMI correlated slightly with the measurements. Measurements in female patients were slightly larger than in their male counterparts between the ages of 0 and 6 years, while male patients tended to have larger values starting from ages 7 to 9 years. These values were significantly larger in male patients from the ages of 16 to 18 years (P < .05).

Conclusion

This study provides normative data on the morphology of pediatric anatomic features in the knee as a basis for age-appropriate and individualized surgical care of ACL and PCL injuries in children and adolescents.

Clinical outcomes of different autografts used for all-epiphyseal, partial epiphyseal or transphyseal anterior cruciate ligament reconstruction in skeletally immature patients - a systematic review

BACKGROUND

Different types of grafts can be used for anterior cruciate ligament reconstruction (ACLR). There is little published data regarding skeletally immature patients. The purpose of this systematic review was to assess the clinical outcomes and complications for different autograft types used in all-epiphyseal, transphyseal and partial epiphyseal/hybrid ACLR in skeletally immature children and adolescents.

METHODS

PubMed, Embase and Cochrane databases were systematically searched for literature regarding ACLR using hamstrings, quadriceps or bone-patellar-tendon-bone (BPTB) autografts in skeletally immature patients. Studies were included if they examined at least one of the following outcomes: graft failure, return to sport(s), growth disturbance, arthrofibrosis or patient reported outcomes and had a minimum follow-up of 1 year. Case reports, conference abstracts and studies examining allografts and extra-articular or over-the-top ACL reconstruction techniques were excluded. Graft failure rates were pooled for each graft type using the quality effects model of MetaXL. A qualitative synthesis of secondary outcomes was performed.

RESULTS

The database search identified 242 studies. In total 31 studies were included in this review, comprising of 1358 patients. Most patients (81%) were treated using hamstring autograft. The most common used surgical technique was transphyseal. The weighted, pooled failure rate for each graft type was 12% for hamstring tendon autografts, 8% for quadriceps tendon autografts and 6% for BPTB autografts. Confidence intervals were overlapping. The variability in time to graft failure was high. The qualitative analysis of the secondary outcomes showed similar results with good clinical outcomes and low complication rates across all graft types.

CONCLUSIONS

Based on this review it is not possible to determine a superior graft type for ACLR in skeletally immature. Of the included studies, the most common graft type used was the hamstring tendon. Overall, graft failure rates are low, and most studies show good clinical outcomes with high return to sports rates.

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.

Graft choices for paediatric anterior cruciate ligament reconstruction: State of the art

The paediatric population is at particularly high risk for anterior cruciate ligament (ACL) injuries due to high rates of sports participation. Other risk factors for ACL injuries in children include but are not limited to being female, generalised ligamentous laxity, a high body mass index (BMI), and poor neuromuscular control. ACL reconstruction (ACLR) is commonly done to treat ACL injuries and allow for return to sports and daily activities. ACL repair is another option with ongoing techniques being developed. The high rates of graft failure in children reported in recent publications on ACL repair are very concerning. Special consideration must be taken in ACLR in the skeletally immature patient due to the risk of growth-related complications, such as limb deformity or growth arrest, that can arise from drilling across or disrupting the physis. Graft choices for paediatric ACLR include iliotibial band (ITB) over the top and over the front, hamstring autograft, bone patellar tendon bone (BTB) autograft, quadriceps tendon autograft, and allograft. Factors for each graft choice to consider include graft size, graft failure rates, donor site morbidity, requirement for bony tunnels, the post-op rehabilitation process, and return to sport outcomes. Each graft has its benefits and disadvantages for the individual patient, depending on age, skeletal maturity, and goals for recovery. Lateral extra-articular tenodesis (LET) is another option to consider with paediatric ACLR because LET has been shown to decrease the re-rupture rate in adult ACLR. After surgery, patient follow-up until at least the growth plates are closed is important. This article aims to provide an overview and comparison of the various graft types to aid in the graft choice decision making process for paediatric ACLR.

Knee valgus and patellofemoral instability after pediatric anterior cruciate ligament reconstruction: a case report and review of the literature

BACKGROUND

Pediatric athletes who undergo anterior cruciate ligament reconstruction are at risk for a growth deformity if the surgery violates the physes.

CASE

A 12-year-old African American boy underwent anterior cruciate ligament reconstruction using a hamstring autograft. The procedure violated the distal femoral growth plate and the perichondrial ring of LaCroix, resulting in a distal femoral lateral physeal growth arrest. Three years later, he had developed a 15° valgus deformity, an increased quadriceps angle and patellofemoral instability. He was able to return to sports after undergoing a distal femoral osteotomy to correct the valgus and medial patellofemoral ligament reconstruction to stabilize the patella.

CONCLUSION

Anterior cruciate ligament reconstruction in athletes with open physes has the potential to cause distal femoral valgus deformity, an increased quadriceps angle, and subsequent patellofemoral instability.

Clinical outcomes and complications after anterior cruciate ligament reconstruction with bone-patellar tendon-bone in patient Tanner 3 and 4: a systematic review

BACKGROUND

Clinical outcomes and potential complications associated with Bone-Patellar Tendon-Bone (BPTB) graft in skeletally immature ACL reconstruction (ACLR) are poorly defined. Considering that in Tanner 1-2 patients this kind of graft is not recommended, we focused our systematic review on the evaluation of all the studies in the literature that reported clinical outcomes and rate of complications of the ACLR using BPTB graft in Tanner 3-4 patients.

METHODS

This review was conducted in accordance with the PRISMA statement. PubMed, Cochrane Library, EMBASE and Scopus were examined from 1965 to 2020 using different combinations of the following keywords: "ACL reconstruction", "skeletally immature", "young", "patellar tendon" and "BPTB". The database search yielded 742 studies, on which we performed a primary evaluation. After carrying out a full-text evaluation for the inclusion criteria, 4 studies were included in the final review and assessed using the Newcastle-Ottawa scale. Ninety-six cases with mean age of 14.2 years were reported.

RESULTS

Good stability and functional outcomes were reported with a mean follow-up of 49.5 months. Return to sport rate ranged from 91.7% to 100%. A KT-1000 side-to-side difference higher than 5 mm was observed in five patients (5.2%). No lower limb length discrepancy and angulation were reported. Graft rupture rate was 5.2%.

CONCLUSION

According to these results, BTPB graft could be a good choice in Tanner 3-4 patients who want to achieve their preinjury sport level with a low risk of growth disturbances and graft failure. Further investigations in a wider population are needed.

Anterior Cruciate Ligament Reconstruction Procedures Using the Iliotibial Band Autograft

The Micheli anterior cruciate ligament (ACL) procedure is a combined intra-articular and extra-articular knee stabilization technique that combines lateral augmentation with ACL reconstruction using the iliotibial band as an autograft for both aspects of the technique. Its primary indication is for ACL reconstruction in skeletally immature patients with more than 2 years of growth remaining. Studies have shown it to be effective at restoring knee biomechanics to have minimal risk of complications, including those associated with growth disturbances and a relatively low ACL graft rupture rate. Additional studies are needed to better understand the potential utilization of this technique and related modifications in the marginally skeletally immature patient, skeletally mature adolescent, adult, and revision ACL reconstruction settings.

Distance to the Neurovascular Bundle for Iliotibial Band Graft Passage During Anterior Cruciate Ligament Reconstruction: A Pediatric Cadaveric Study

Background:

The Micheli technique for anterior cruciate ligament (ACL) reconstruction (ACLR) has proven to be a reliable method with a minimal risk for growth disturbance among skeletally immature patients.

Purposes:

To evaluate the Micheli technique of iliotibial band (ITB) graft passage for ACLR using cadaveric knee models and to measure the distance between the surgical instrument tip and the neurovascular bundle in the posterior knee joint: specifically, the peroneal nerve, tibial nerve, and popliteal artery.

Study Design:

Descriptive laboratory study.

Methods:

Gross dissection was performed on 17 pediatric cadaveric knees (12 male and 5 female) aged between 4 and 12 years. To simulate ITB graft passage, we passed a curved-tip hemostat clamp through the posterior capsule, with the knee flexed from 90° to 100°. Next, clinical photographs were taken, and digital imaging software was used to measure the distance in centimeters from the clamp tip to each respective neurovascular structure.

Results:

The mean distances from the clamp tip to the tibial nerve, popliteal artery, and peroneal nerve were 0.875 cm (range, 0.468-1.737 cm), 0.968 cm (range, 0.312-1.819 cm), and 1.149 cm (range, 0.202-2.409 cm), respectively. Mean values were further calculated for age groups of ≤8, 9-10, and 11-12 years. The mean distance from the clamp tip to the peroneal nerve was 1.400 cm larger for 11- to 12-year-old specimens than for ≤8-year-old specimens (95% CI, 0.6-2.2 cm; P = .005).

Conclusion:

The neurovascular structures in the posterior knee were in close proximity to the path of graft passage, with distances <1 cm in many specimens in this study. When passing the graft through the knee for an over-the-top position, surgeons should consider these small distances between the path of graft passage and critical neurovascular structures.

Clinical Relevance:

As the incidence of ACL tears is continuously increasing within the pediatric population, there are a larger number of ACLR procedures being performed. Although neurovascular injuries during ACLR are rare, this study clarifies the close proximity of neurovascular structures during ITB graft passage using the Micheli technique of ACLR.

Anterior Cruciate Ligament Rupture in Skeletally Immature Patients

In the past 20 years, sports injuries in pediatric and adolescent athletes have increased dramatically, with anterior cruciate ligament (ACL) injuries accounting for more than 25% of all knee injuries at this age. Diagnosis is based on detailed clinical history, physical examination, and imaging assessment, where magnetic resonance imaging plays a central role. The growing immature skeleton presents specific characteristics, which require unique methods for surgical reconstruction, ideally avoiding the physes or minimizing the risk of damaging them. Specific rehabilitation protocols are needed, and these patients face a higher risk of recurrent and contralateral ACL injury. Nonsurgical treatment or delayed reconstruction has been associated with persistent instability, activity modifications, worst functional outcomes, and increased risk of irreparable injuries to menisci and articular cartilage. Consequently, surgical stabilization is the preferred treatment for most patients, despite the eventual risk of angular deformities or limb-length discrepancies due to iatrogenic physeal injury. A variety of surgical techniques have been described, depending on the skeletal maturity and growth remaining. Targeted prevention programs play a key role in reducing the risk of ACL injury, are easy to implement, and require no additional equipment. High-quality evidence supports its use in all pediatric athletes.

Lateral extra-articular tenodesis and anterior cruciate ligament reconstruction in young patients: clinical results and return to sport

Lateral extra-articular tenodesis (L.E.T.) have been proposed to reduce the tibia's anterior translation and internal rotation in concomitant to Anterior cruciate ligament (A.C.L.) reconstruction. Recent studies show that the addition of L.E.T. to A.C.L. reconstruction results in a statistically significant reduction in graft failure. The purpose of the present study was to evaluate the clinical outcomes, complications, and rate of return to preinjury sports level in pediatric patients who underwent combined A.C.L. reconstruction with L.E.T. at a minimum 2-year follow-up. The authors retrospectively evaluated 42 pediatric patients at high risk of graft failure who experienced ACLR connected to L.E.T. IKDC and Tegner-Lysholm Knee Scores Scale were used to assess clinical outcomes, and the Tegner Activity Scale to evaluate the return to sport. No graft failure or subsequent surgery related to A.C.L. reconstruction occurred. Furthermore, 88% of patients returned to the sport. Satisfactory clinical results were obtained on a short and medium-term follow-up. These findings help to consider this procedure for active adolescents at a high risk of graft failure to enhance A.C.L. reconstruction.

Paediatric Anterior Cruciate Ligament (ACL) Injuries: Current Concepts Review

BACKGROUND

Over the past two decades, there has been a documented increase in paediatric ACL injuries because of a rise in younger age sports participation at the competitive level, awareness about sports-related injuries, and advanced imaging modalities.

METHODS

A PubMed electronic database search was done, which revealed 1366 hits over the last five years (2016 - 2020). Finally, 37 articles that contributed to new findings were included. This review was conducted based on predefined research questions.

RESULTS AND CONCLUSION

Early surgical reconstruction is recommended in children due to the increasing demand for early return to sports and to prevent the instability that can lead to progressive cartilage and meniscal damage. With the evolution of several "physeal sparing" ACL reconstruction (ACLR) techniques, a favorable clinical outcome with less growth disturbance is achievable. Although different autograft options are available, hamstring autografts are most commonly preferred. A specific pattern of a bone bruise not extending into the metaphysis, and lateral meniscus tears are the most common associated injuries. Following paediatric ACLR, complications like graft rupture and contralateral ACL injuries are two to three folds higher than with adult ACLR. Unprepared early return to sports is one of the reasons for increased complication rates in children; thus, clearance criteria for return to sports need to be standardized, and early return to sports (< 9 months post ACLR) should be avoided. Neuromuscular training protocols are recommended to minimize complications like graft ruptures.

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).

Anatomic all-epiphyseal ACL reconstruction with "inside-out" femoral tunnel placement in immature patients yields high return to sport rates and functional outcome scores a minimum of 24 months after reconstruction

PURPOSE

To understand if anatomic physeal-sparing ACL reconstruction in the immature host preserves range of motion, permits a return to sports, and avoids limb length discrepancy and accelerated intra-articular degeneration with a cross-sectional radiographic, physical examination and patient-reported outcomes analysis.

METHODS

A cross-sectional recall study included 38 patients aged 7-15 who underwent all-epiphyseal ACL reconstruction with hamstring allograft performed by a single surgeon at a large academic medical center. All-epiphyseal reconstructions were performed using a modified Anderson physeal-sparing technique, with the femoral tunnel placed using an "inside-out" technique. Assessments consisted of a physical exam, long leg cassette radiographs, KT-1000 measurements, subjective patient metrics, and magnetic resonance imaging.

RESULTS

Thirty-eight (56.7%) of 66 eligible patients returned for in-person clinical and radiographic exams. Patients were 11.4 ± 1.8 years at the time of surgery. Five patients were females (13.2%). Mean follow-up was 5.5 ± 2.4 years. ACL re-injuries occurred in four patients (10.5%), all of whom underwent revision reconstructions. Thirty-three of the remaining 34 (97.1%) patients returned to sports following their reconstruction, and 24 (70.6%) returned to their baseline level of competition. Mean limb length discrepancy (LLD) was 0.2 ± 1.4 cm. Nine patients had an LLD of > 1 cm (26.5%), which occurred at an equivalent age as those with < 1 cm LLD (10.8 ± 2.0 vs. 11.7 ± 1.7, n.s.). Pre-operative Marx scores (13.1 ± 3.5) were not significantly different from post-operative values (12.3 ± 5.1, n.s.). Patients who required ACL revisions had significantly lower Marx scores than those with intact primary grafts (8.3 ± 7.1 vs. 13.4 ± 4.5, p = 0.047). Cohort mean International Knee Documentation Committee (IKDC) score was 89.7 ± 12.7.

CONCLUSION

Anatomic all-epiphyseal anatomic ACL reconstruction appears to be useful in patients with significant projected remaining growth, with good return-to-sport outcomes and minimal risk of clinically significant physeal complications. However, given the limited patient recall possible in the present study, further large sample size, high-quality works are necessary to validate our findings.

LEVEL OF EVIDENCE

Level IV.

Complication rates following all-epiphyseal ACL reconstructions in skeletally immature patients: A retrospective case series study

The aim was to evaluate the safety of a physeal-sparing anterior cruciate ligament reconstruction technique (ACLR), performed with Orthopediatrics (Warsaw, IN) equipment, by assessing complications.Skeletally immature patients who underwent all-epiphyseal ACLR between 2015 and 2017 with postoperative follow-up were included in this retrospective study. Complications, demographic, clinical, surgical, and imaging data was retrieved from an urban tertiary pediatric hospital database. Physeal status, limb-length discrepancies (LLD), and angular deformities were assessed on preoperative and postoperative radiographs, growth disturbances were reported, and initial and follow-up diameters of tunnels were compared.Nineteen ACLRs were included from 18 patients, 4 females and 14 males, with bone age at surgery of 13.3 ± 1.0 years. At a mean follow-up of 19.2 ± 10.1 months, there were no symptomatic growth disorders requiring intervention. There were: 2 (11.1%) unilateral early physeal closures, 2 (10.5%) new angular deformities (5°-10°), 4 (22.2%) LLD (1-2 cm), 1 (5.6%) contralateral ACLR, 1 (5.6%) femoral screw removal, 2 (10.5%) graft ruptures, and 1 meniscal tear (5.3%). Mean tunnel widening was 1.7 mm and 1.5 mm on the femoral and tibial side, respectively, and no massive osteolysis was recorded at the polyetheretherketone implant site.The complication rates were comparable to those in similar studies, with no growth-related complications at 19.2 months.

Clinical Outcomes and Postoperative Complications After All-Epiphyseal Double-Bundle ACL Reconstruction for Skeletally Immature Patients

Background

The treatment strategy for pediatric anterior cruciate ligament (ACL) tears, especially in patients with open physes, remains controversial.

Purpose

To assess clinical outcomes and postoperative complications after all-epiphyseal double-bundle ACL (DB-ACL) reconstruction for patients with open physes.

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 102 patients aged ≤15 years who underwent ACL reconstruction at a single institution and had a minimum of 2 years of follow-up. Of these patients, 18 had undergone all-epiphyseal DB-ACL reconstruction (mean age, 12.4 ± 1.2 year) and 84 had undergone conventional DB-ACL reconstruction (mean age, 14.1 ± 0.9 year). The outcomes of the all-epiphyseal group were compared with those of the conventional group. Objective clinical outcomes included KT-1000 arthrometer measurements of side-to-side difference in anterior tibial translation, Lachman test grade, and pivot-shift test grade. Radiographic angular deformity (defined as >3° of the side-to-side difference in femorotibial angle) and incidence of second ACL injury were also compared.

Results

The postoperative side-to-side difference in laxity significantly improved from 6.1 ± 2.4 to 0.6 ± 0.9 mm in the all-epiphyseal group (P = .001), and postoperative laxity was similar to that of the conventional group (0.4 ± 0.8 mm; P = .518). A Lachman grade 1 positive result was observed in 20% of the all-epiphyseal group and 3% of the conventional group (P = .042), and a pivot-shift grade 1 positive result was observed in 22% of the all-epiphyseal group and 4% of the conventional group (P = .074). A total of 4 patients (26.7%) in the all-epiphyseal group and 4 (6.1%) in the conventional group demonstrated angular deformity (P = .035). The incidence of postoperative ipsilateral ACL tear was 16.7% in the all-epiphyseal group and 23.8% in the conventional group (P = .757). The incidence of contralateral ACL tear was 11.1% in the all-epiphyseal group and 14.3% in the conventional group (P ≥ .999).

Conclusion

All-epiphyseal DB-ACL reconstruction for skeletally immature patients achieved satisfactory clinical outcomes compared with conventional DB-ACL reconstruction. The incidence of ipsilateral graft rupture was relatively high in both groups. The all-epiphyseal group had a significantly higher incidence of angular deformity.

Treatment Decisions in Pediatric Sports Medicine: Do Personal and Professional Bias Affect Decision-Making?

Background:

Personal and professional biases can affect decision-making regarding important issues in pediatric sports medicine. Gaining insight into the opinions of health care professionals who specialize in pediatric sports medicine will provide information that may be useful for directing ongoing research in this field.

Hypothesis:

It was hypothesized that surgeons would demonstrate bias toward early surgical intervention versus nonsurgeons. In addition, it was hypothesized that youth sports medicine professionals who were parents of a child with a previous major sports injury or concussion would be less likely to allow their child to play American tackle football or return to football after a concussion.

Study Design:

Cross-sectional study.

Methods:

An online survey was provided to the active members of the Pediatric Research in Sports Medicine Society. We used both professional background information and responses to questions related to personal experiences with youth sports injuries to determine potential factors associated with underlying biases. Survey responses among subgroups were compared using the Fisher exact test. The Pearson correlation coefficient was used to evaluate years in practice versus opioid use.

Results:

Of the survey participants, 62.5% were pediatric surgeons, and 37.5% represented different nonsurgical youth sports medicine professions. Surgeons were less likely than nonsurgeons to agree to allow their child to return to football after sustaining a concussion and completing a concussion protocol (48% vs 76%, P = .013). Surgeons were more likely than nonsurgeons to agree to both elective shoulder stabilization after a first-time dislocation and elective drilling of a stable knee osteochondritis dissecans (OCD) before nonoperative treatment (41% vs 10%, P = .003 and 52% vs 23%, P = .013, respectively). Those who reported having a child with a concussion history were more likely to support him or her returning to football after a concussion (65% vs 33%, P = .026).

Conclusion:

Surgeons were more likely to favor elective shoulder-stabilization surgery after a first-time dislocation and drilling of a stable knee OCD instead of nonoperative management. Personal experience of having a child who sustained a major sports injury or concussion did not demonstrate a bias against participation in football or return to football after a concussion.

Skeletally immature patient showed lower graft maturity than skeletally mature patient after ACL reconstruction with a rounded rectangular femoral tunnel

To compare the clinical results and ligamentization of anterior cruciate ligament reconstruction (ACLR) between skeletally immature and mature patients. Two-hundred-and-two patients who underwent primary ACLR were evaluated retrospectively. The clinical outcomes were compared between skeletally immature (immature group 1, n = 27) and mature (control group 1, n = 175) groups. Graft ligamentization of the reconstructed anterior cruciate ligament (ACL) using magnetic resonance imaging (MRI) signal intensity at 6 months postoperatively was compared between immature group 2 (n = 16), which included participants from immature group 1, and control group 2 (n = 32), created by recruiting data-matched controls from control group 1. Immature group 1 had significantly higher revision (14.8%) and pivot shift test positive (22.2%) rates than control group 1 (2.9% and 4.0%, respectively) (P = 0.020 and 0.003, respectively). The signal intensity in immature group 2 were significantly higher at the mid-substance and distal site of the reconstructed ACL than those in control group 2 (P = 0.003 and 0.034, respectively). Skeletally immature patients had higher graft revision and residual rotational laxity rates. Reconstructed ACL in skeletally immature patients showed higher signal intensity on MRI at 6 months postoperatively.

Association Between Knee Alignment and Meniscal Tear in Pediatric Patients with Anterior Cruciate Ligament Injury

BACKGROUND

The present study aimed to evaluate the association between elapsed time from anterior cruciate ligament (ACL) injury to surgical treatment and the incidence of meniscal tears in a cohort of patients ≤16 years old with varus-aligned and non-varus-aligned knees.

METHODS

The study cohort included 123 patients ≤16 years old who underwent primary ACL reconstruction between January 2016 and March 2020. Knee alignment was expressed as the hip-knee-ankle angle (HKAA), as measured preoperatively on an anteroposterior view of 3-dimensional computed tomography of the full length of the lower limb. Varus alignment was defined as an HKAA ≥181.0°, and non-varus alignment was defined as an HKAA <181.0°. Patients were divided into groups according to knee alignment and the elapsed time from injury to surgical treatment: early-treatment group (<60 days) and delayed-treatment group (≥60 days).

RESULTS

A total of 64 varus-aligned and 59 non-varus-aligned knees were identified. Among patients with varus-aligned knees, those in the delayed-treatment group showed a significantly lower rate of lateral meniscal tears (6 of 30, 20%) compared with those in the early-treatment group (17 of 34, 50%; p = 0.015). Among patients with non-varus-aligned knees, there was no significant difference in meniscal tears of any type between the early and delayed-treatment groups. Among patients without medial meniscal injury identified on initial magnetic resonance imaging, those with varus-aligned knees in the delayed-treatment group showed a significantly higher rate of medial meniscal tears at the time of the surgical procedure (8 of 20, 40%) compared with those with non-varus-aligned knees (1 of 18, 6%; p = 0.015).

CONCLUSIONS

Delayed ACL reconstruction in patients ≤16 years old with varus-aligned knees might be associated with an increased incidence of secondary medial meniscal tears. Accordingly, earlier ACL reconstruction in patients with varus-aligned knees should be considered.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Influential Articles on Pediatric and Adolescent Anterior Cruciate Ligament Injuries: A Bibliometric Analysis

BACKGROUND

The understanding of pediatric anterior cruciate ligament (ACL) injuries and optimal treatment has evolved significantly. Influential articles have been previously evaluated using article citations to determine impact.

PURPOSE

To identify and characterize the 50 most cited and recent influential articles relating to pediatric and adolescent ACL injuries, to examine trends in publication characteristics, and to evaluate correlations of study citations with quality of evidence.

STUDY DESIGN

Cross-sectional study.

METHODS

The top 50 most cited articles on pediatric and adolescent ACL injuries were gathered using the Web of Science and Scopus online databases by averaging the number of citations from each database. Articles from recent years were also aggregated and sorted by citation density (citations/year). Publication and study characteristics were recorded. Level of evidence and methodologic quality were assessed where applicable using the modified Coleman Methodology Score (mCMS), modified Jadad scale, and Methodological Index for Non-Randomized Studies (MINORS). Spearman correlation was used to evaluate the association between citation data and level of evidence or methodologic quality scorings.

RESULTS

The top 50 cited papers had a mean of 117.5 ± 58.8 citations (range, 58.5-288.5 citations), with a mean citation density of 9.4 ± 5.4 citations per year (range, 2.9-25.8 citations/year); 80% were published in 2000 or later, and 6% were considered basic science. Articles were mainly level 4 evidence (27/42; 64.3%), and none was level 1. There were moderate, significant associations between publication year and level of evidence (r S = -0.45; P = .0030) and citation density and publication year (r S = 0.59; P < .001). Mean methodologic quality scores were as follows: mCMS, 53 ± 7.2 (range, 39-68); modified Jadad scale, 3.2 ± 1.1 (range, 2-6); and MINORS, 11.2 ± 3.2 (range, 6-20). There was a significant, strong correlation between rank of mean citations and modified Jadad scale (r S = 0.76; P < .0001), suggesting poorer score associated with more mean citations.

CONCLUSION

Influential articles on pediatric and adolescent ACL injuries were relatively recent, with a low proportion of basic science-type articles. Most of the studies had a lower evidence level and poor methodologic quality scores. Higher methodologic quality did not correlate positively with citation data.

Anterior Cruciate Ligament Reconstruction and Lateral Plasty in High-Risk Young Adolescents: Revisions, Subjective Evaluation, and the Role of Surgical Timing on Meniscal Preservation

BACKGROUND

In adolescents, the rate of meniscal injury at the time of anterior cruciate ligament (ACL) reconstruction, the rate of ACL graft revision, and clinical outcomes has not yet been investigated.

HYPOTHESIS

In patients younger than 16 years, the rate of meniscal injuries at the time of ACL reconstruction increases with time from injury. The mid-term revision rate and reoperation rate after ACL reconstruction with hamstrings and lateral tenodesis are lower than those reported in literature for isolate ACL reconstruction.

STUDY DESIGN

Case series.

LEVEL OF EVIDENCE

Level 4.

METHODS

Patients younger than 16 years who underwent ACL reconstruction with hamstring and lateral tenodesis, with a follow-up ≥2 years were included. The number of meniscal lesions was stratified according to the delay between injury-to-surgery (<3, 3-12, >12 months). All reoperations, Lysholm score, Knee Injury and Osteoarthritis Outcome Score subscales for pain (at rest and during activity), and return to sport were collected.

RESULTS

A total of 151 patients (mean age 14.8 ± 1.2 years) were included. Patients undergoing surgery at <3 months after injury had a lower meniscal injury rate (36%) than those treated at 3 to 12 months (55%) and >12 months (63%) after injury (P = 0.04). Medial meniscal lesions were more likely to be repaired when surgery was performed <3 months after injury (91%). Subjective follow-up data were available for 132 patients, and 19 were lost to follow-up. At 6.0 ± 2.6 years, 6% of patients underwent ACL revision; 1 of 20 (5%) patients with posterior tibial slope ≥12° and 4 of 45 (9%) patients with Tegner level ≥8. Nine new meniscal procedures were performed; 19% of repaired menisci underwent meniscectomy. Good or excellent Lysholm score was reported by 88% of patients; 56% of patients with concurrent lateral meniscectomy had pain during activity, 91% returned to sport, and 79% were still participating at final follow-up.

CONCLUSION

Patients younger than 16 years undergoing ACL reconstruction within 3 months from injury had the lowest rate of meniscal injuries. ACL reconstruction with lateral tenodesis had low revision rate (6%) and good or excellent clinical outcomes in 88% of young adolescents.

CLINICAL RELEVANCE

Sport physicians should be aware that adolescent patients undergoing ACL reconstruction within 3 months after injury have the lowest rate of meniscal injuries; the mid-term revision rate of ACL reconstruction with lateral plasty is lower than 10% and the patients' perceived outcomes are good with almost all patients returning to sport activity.

Quadriceps Strength Is Influenced by Skeletal Maturity in Adolescents Recovering From Anterior Cruciate Ligament Reconstruction

BACKGROUND

Anterior cruciate ligament injuries and anterior cruciate ligament reconstructions (ACLRs) are common, especially in adolescent patients. Recovery of strength, jumping performance, and perceived/subjective function are often used to make a return to sports decisions after injury. It is unknown how skeletal maturity may influence strength recovery after ACLR. The purpose of this study was to compare the strength and patient-reported outcomes in adolescent ACLR patients with and without open distal femur and proximal tibia physes.

METHODS

One hundred seventeen consecutive patients under the age of 18 were referred for routine strength and subjective outcomes evaluation following ACLR, 100 were included in the final analyses after excluding those with prior injuries, those tested outside for 4 to 12 month postoperative window, and those with incomplete clinical data. All study patients completed patient-reported outcomes, and underwent isometric and isokinetic testing of knee extensor and flexor strength to calculate normalized peak torque and limb symmetry. Statistical analyses were performed on all outcomes data using a 2×2 (physeal status: open, closed; and sex: male, female) with analysis of covariance where age and preoperative activity level were used as covariates.

RESULTS

A significant interaction between sex and physeal status for isokinetic knee extension peak torque and isometric knee extension peak torque, and limb symmetry index was found. This indicated that males with open physes were stronger and more symmetric than males with closed physes and females with open physes at ~6 months post-ACLR. There were no differences between sexes for patients with closed physes. No interactions were observed for flexion strength. Male patients and patients with open physes had higher perceived knee function compared with their corresponding counterparts.

CONCLUSIONS

After ACLR, adolescent patients with open physes had higher quadriceps strength compared with patients with closed physes. Overall, those skeletally less mature patients actually fared better on the functional strength tests, suggesting that functional recovery is not hindered by the presence of an incompletely closed physis.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Incidence of anterior cruciate ligament graft tears in high-risk populations: An analysis of professional athlete and pediatric populations

BACKGROUND

Professional athletes are at increased risk of injury with high activity levels and additional pressure to return to sports quickly after anterior cruciate ligament (ACL) injury. The purpose of this study was to determine ACL graft re-tear rates in National Basketball Association (NBA), Major League Baseball (MLB), and National Hockey League (NHL) athletes using publicly available databases and to compare these to general populations, National Football League (NFL) athletes, and the pediatric population to establish a baseline for those partaking in high-risk sporting activity.

METHODS

A comprehensive online search was performed to identify athletes in the NBA, MLB, and NHL who had a reported ACL tear between 2007 and 2017. For each tear, the type of tear (initial or re-tear) and return to play data were documented. Comparisons of re-tear rates from these leagues to prior registry, meta-analyses, and epidemiologic studies were performed using Fisher's exact or Chi-squared tests.

RESULTS

The aggregate re-tear rate was 11.9%. ACL re-tear rates by league did not statistically differ. Return to play rate after index surgery was 95.8%, whereas after a revision procedure was 92.3%. There was a statistically significant difference between the studied ACL re-tear rates (NBA, MLB, NHL) and those of national registries (P < 0.01), and no difference when compared with the pediatric population or with the NFL.

CONCLUSIONS

Exposure to higher-risk sporting activity, common to pediatric patients and professional athletes, is a likely major influential factor in ACL re-tear.

Failure Rates of Autograft and Allograft ACL Reconstruction in Patients 19 Years of Age and Younger: A Systematic Review and Meta-Analysis

BACKGROUND

Graft choice for pediatric anterior cruciate ligament reconstruction (ACLR) is determined by several factors. There is limited information on the use and outcomes of allograft ACLR in pediatric patients. The purpose of this systematic review and meta-analysis was to quantify reported failure rates of allograft versus autograft ACLR in patients ≤19 years of age with ≥2 years of follow-up. We hypothesized that there would be higher rates of failure for allograft compared with autograft ACLR in this population.

METHODS

PubMed/MEDLINE and Embase databases were systematically searched for literature regarding allograft and autograft ACLR in pediatric/adolescent patients. Articles were included if they described a cohort of patients with average age of ≤19 years, had a minimum of 2 years of follow-up, described graft failure as an outcome, and had a Level of Evidence grade of I to III. Qualitative review and quantitative meta-analysis were performed to compare graft failure rates. A random-effects model was created to compare failure events in patients receiving allograft versus autograft in a pairwise fashion. Data analysis was completed using RevMan 5.3 software (The Cochrane Collaboration).

RESULTS

The database search identified 1,604 studies; 203 full-text articles were assessed for eligibility. Fourteen studies met the inclusion criteria for qualitative review; 5 studies were included for quantitative meta-analysis. Bone-patellar tendon-bone (BTB) represented 58.2% (n = 1,012) of the autografts, and hamstring grafts represented 41.8% (n = 727). Hybrid allografts (autograft + supplemental allograft) represented 12.8% (n = 18) of all allograft ACLRs (n = 141). The unweighted, pooled failure rate for each graft type was 8.5% for BTB, 16.6% for hamstring, and 25.5% for allograft. Allografts were significantly more likely than autografts to result in graft failure (odds ratio, 3.87; 95% confidence interval, 2.24 to 6.69).

CONCLUSIONS

Allograft ACLR in pediatric and adolescent patients should be used judiciously, as existing studies revealed a significantly higher failure rate for allograft compared with autograft ACLR in this patient population. Additional studies are needed to improve the understanding of variables associated with the high ACLR failure rate among pediatric and adolescent patients.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Revision ACL Reconstruction in Adolescent Patients

Background:

High failure rates have been documented after anterior cruciate ligament reconstruction (ACLR) in pediatric patients, and revision surgery is indicated due to high activity levels of children and adolescents.

Purpose:

To define trends in revision ACLR in patients who underwent initial ACLR at younger than 18 years.

Study Design:

Case series; Level of evidence, 4.

Methods:

An electronic medical record was used to retrospectively identify revision ACLR procedures performed by 2 surgeons between the years 2010 and 2016 in patients younger than 18 years at initial reconstruction. Descriptive information, intraoperative findings, surgical techniques, and rehabilitation data were recorded from initial and revision surgeries. Descriptive statistics were used.

Results:

A total of 32 patients (17 girls, 15 boys) met the inclusion criteria, with a mean age of 15.8 years at initial reconstruction. For initial reconstructions, 15 patients underwent transphyseal procedures, 3 patients underwent adult-type procedures using an anatomic reconstruction technique that did not take into account the physis, and 2 patients underwent partial intraepiphyseal procedures. Graft types included hamstring autograft (n = 17), allograft (n = 5), hybrid (n = 4), and bone–patellar tendon–bone autograft (BTB; n = 3). Average primary reconstruction graft diameter was 8.0 mm (girls, 7.72 mm; boys, 8.36 mm; P = .045). After initial reconstruction, 10 patients had postoperative protocol noncompliance, and 8 patients reported delayed recovery. Mean time to retear was 565 days (range, 25-1539 days). At revision, BTB autograft was used in 50% (n = 16), followed by hamstring autograph (31.3%; n = 10) and allograft (12.5%; n = 4); mean graft diameter was 9.05 mm. Chondral surgery was more common during revision (25% for revision vs 0% for index; P = .031). There were 4 patients who required staged reconstruction with bone grafting. At mean final follow-up of 29.5 months (SD, 22.2 months), there were 3 graft failures (9.4%) and 5 contralateral ACL ruptures (15.6%).

Conclusion:

Most patients with ACL graft failure were adequately treated with a single revision. Conversion from a soft tissue graft to a BTB autograft was the most common procedure. Infrequently, patients required staged reconstructions. Providers should have a high index of suspicion for associated intra-articular injuries resulting from graft failure in adolescent patients.

An In-Depth Analysis of Graft Rupture and Contralateral Anterior Cruciate Ligament Rupture Rates After Pediatric Anterior Cruciate Ligament Reconstruction

BACKGROUND

Reported rates of graft rupture and contralateral anterior cruciate ligament (ACL) rupture after ACL reconstruction (ACLR) are higher among pediatric patients than adults. Previous series may have underestimated postoperative event risk because of small sample sizes and high proportions of dropouts.

PURPOSE

To calculate rates of graft rupture and contralateral ACL rupture after ACLR in a large pediatric series.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

ACLRs performed in our tertiary care children's hospital system over a period of >7 years were identified through billing review. Cases were sorted based on operative technique, with all-epiphyseal ACLRs considered separately. Transphyseal ACLRs were divided into 2 groups based on patient age, with a cutoff of 16 years. Clinic follow-up data as well as prospectively collected survey data were used to note graft rupture and contralateral ACL rupture events. Rates of graft rupture and contralateral ACL rupture were calculated using Kaplan-Meier survival analysis.

RESULTS

The final data set included 996 patients. A total of 161 patients underwent all-epiphyseal ACLR. Of the remaining transphyseal surgeries, 504 patients were <16 years of age at the time of surgery and 331 were ≥16 years. The 4-year cumulative rate of graft rupture via Kaplan-Meier survival analysis was 19.7% among all patients. The rate was 18.2% among all-epiphyseal ACLRs, 21.6% among transphyseal ACLRs in patients <16 years, and 16.4% among transphyseal ACLRs in patients ≥16 years (P = .855). Survival analysis estimated the 4-year cumulative rate of contralateral ACL rupture at 12.0% among all patients: 6.63% among all-epiphyseal ACLRs, 15.7% among transphyseal ACLRs in patients <16 years, and 8.05% among transphyseal ACLRs in patients ≥16 years (P = .093).

CONCLUSION

This is the largest series of pediatric ACLRs yet reported, and it shows that the risks of another ACL injury after first-time ACLR are higher than previously reported. The risk of contralateral ACL rupture was lower than that for graft rupture. Our methods, including prospective follow-up surveys and survival analysis to generate cumulative rate estimates, provide a best-practice example for future case series calculations. Our results provide insight into the postoperative course of pediatric patients undergoing ACLR and are crucial for preoperative patient and family counseling. Understanding these risks may also influence return-to-play decisions.

ACL injuries before 15 years of age: could the young become an athlete?

PURPOSE

The purpose of this study was to systematically assess the possibility for a patient younger than 15 to return to a competitive level of sport following an ACL injury.

METHODS

Four databases were analyzed (PubMed, MedLine, Cinahl, Cochrane Library and LISTA). The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used to guide the screening of the literature. Studies about functional and surgical treatments were included with a minimum of 5 years of mean follow-up. Methodological quality of individual studies was assessed with the Methodological Index for Non-Randomized Studies scale.

RESULTS

Ten studies were included, corresponding to a total of 217 patients. All studies were retrospective with level 4 evidence. Seven studies reported results of a transphyseal technique reconstruction, two studies a physeal-sparing reconstruction, and one studied the results of a repair (« healing response »). Only one study compared functional treatment and surgery. The mean age of patients at the time of surgery was 12.29 years (range 2-16) with a mean follow-up of 7.9 years (range 5.5-18.3). Return to sport was possible for 80 to 100% of patients (average of 91.7%) at the final follow-up but the level for return to sport was reported in only four studies and found between 61 and 89% for return to the same level and at 42% for return to a competitive level. Evolution of the Tegner score was analyzed in five studies and was reported to decrease at the follow-up in three studies. ACL re-ruptures can be considered as failure of the graft (nine studies with surgical technique) and occurred with an average of 16%.

CONCLUSION

This review demonstrate that ACL reconstruction is superior to conservative treatment and 'healing response' in terms of revision rates and knee laxity. Return to sport is possible for more than 4/5 of patients but only two thirds of them were able to return to the same level or to competitive level, and failure rates of the graft were not superior to global population. However, qualities of included studies and variability of treatment limited the clinical application of results. Despite this, patients and parents should be informed that ACL injuries are lesions that may influence the level of sport at a 5-year follow-up.

LEVEL OF EVIDENCE

Level IV, systematic review.

Anterior Cruciate Ligament Re-tear and Revision Reconstruction in the Skeletally Immature Athlete

PURPOSE OF REVIEW

With an increase in high-demand sporting activity, the rate of pediatric and adolescent anterior cruciate ligament (ACL) reconstruction is increasing. Yet, the failure rates after reconstruction are much higher than the adult population. The purpose of this paper is to understand failure rates, reasons for graft failure, and strategies for successful revision surgery.

RECENT FINDINGS

A complete understanding of the failure etiology is essential for the clinician treating this population prior to revision. This begins with an assessment of post-operative patient compliance and sporting activity. Surgical technique must then be scrutinized for non-anatomic tunnel placement and poor graft size/type. Concurrent bony deformity must also be addressed including lower extremity valgus alignment and tibial slope abnormalities. Meniscus and chondral injury must be aggressively treated. Furthermore, imaging must be examined to look for missed posterolateral corner injury. Lateral extra-articular tenodesis (in the setting of ligamentous laxity or rotational instability) may be also indicated as well. The surgeon can then choose a graft type and surgical technique that optimizes outcome and respects skeletal growth. Prior to surgical intervention, the clinician must also counsel patients in regard to the guarded prognosis and outcomes in this setting. Prolonged rehabilitation protocols/return-to-play timing as well as sporting activity modification in the post-operative period after revision are critical. There is limited literature on revision ACL reconstruction in the skeletally immature athlete. An understanding of all the risk factors for failure is essential in order to achieve treatment success.

Transphyseal Anterior Cruciate Ligament Reconstruction in the Skeletally Immature: Quadriceps Tendon Autograft Versus Hamstring Tendon Autograft

Background:

It is unclear what the optimal graft choice is for performing anterior cruciate ligament (ACL) reconstruction in a skeletally immature patient.

Purpose:

To evaluate outcomes and complications of skeletally immature patients undergoing transphyseal ACL reconstruction with a hamstring tendon autograft versus a quadriceps tendon autograft.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Between 2012 and 2016, 90 skeletally immature patients from a single institution underwent primary transphyseal ACL reconstruction with either a quadriceps tendon autograft or a hamstring tendon autograft based on surgeon preference (n = 3). Patient demographic, injury, radiographic, and surgical variables were documented. Outcome measures included the Lysholm score, Single Assessment Numeric Evaluation (SANE), Tegner activity score, pain, satisfaction, and complications such as graft tears and physeal abnormalities.

Results:

A total of 83 patients (56 hamstring tendon, 27 quadriceps tendon) were available for a minimum follow-up of 2 years or sustained graft failure. The mean age of the patients was 14.8 ± 1.4 years at the time of ACL reconstruction. No differences in chronological age, bone age, sex, patient size, or mechanism of injury were noted between groups. There were no differences in surgical variables, except that the quadriceps tendon grafts were larger than the hamstring tendon grafts (9.6 ± 0.6 mm vs 7.8 ± 0.7 mm, respectively; P < .001). Patient outcomes at a mean follow-up of 2.8 ± 0.9 years revealed no differences based on graft type, with mean Lysholm, SANE, pain, satisfaction, and Tegner scores of 96, 93, 0.6, 9.6, and 6.6, respectively, for the quadriceps tendon group and 94, 89, 0.9, 9.2, and 7.1, respectively, for the hamstring tendon group. While there were no physeal complications in either group, patients undergoing ACL reconstruction with a hamstring tendon autograft were more likely to tear their graft (21% vs 4%, respectively; P = .037).

Conclusion:

Skeletally immature patients undergoing ACL reconstruction can be successfully managed with either a quadriceps tendon autograft or a hamstring tendon autograft with good short-term outcomes, high rates of return to sport, and low rates of physeal abnormalities. The primary differences between grafts were that the quadriceps tendon grafts were larger and were associated with a lower retear rate. ACL reconstruction performed with a quadriceps tendon autograft may reduce early graft failure in skeletally immature patients.

Comparing Outcomes Between the Over-the-Top and All-Epiphyseal Techniques for Physeal-Sparing ACL Reconstruction: A Narrative Review

A variety of techniques are used for physeal-sparing anterior cruciate ligament (ACL) reconstruction; however, there is no clear consensus on the ideal surgical technique, the frequency of complications, and how to best avoid growth disturbance. The purpose of this study was to compare outcomes and complications between over-the-top and all-epiphyseal ACL reconstruction techniques. The hypothesis was that both physeal-sparing reconstruction techniques are efficacious, with similar risk of growth disturbance and complications. The Embase and PubMed databases were queried for studies on ACL ruptures in the skeletally immature population from 1985 to 2018. Full-text English studies were included (N = 160). Studies reporting rerupture and/or complications after physeal-sparing ACL reconstruction, specifically growth disturbance, were included (n = 10). Studies were separated into 2 groups: an all-epiphyseal group with femoral and tibial fixation points within the epiphysis and a group that had over-the-top femoral and tibial physeal-sparing reconstruction. Complications not specific to the pediatric population were excluded. Demographics, evaluation of skeletal maturity, surgical technique, growth disturbance, rerupture, and patient-reported outcome scores were collected. Data were analyzed in aggregate. The 10 studies included 482 knees. The mean age was 12.0 years; 81% of patients were male; and mean follow-up was 47.7 months. A total of 178 patients underwent all-epiphyseal reconstruction, and 298 had the femoral graft placed over the top. The rerupture rate was 9.0% (16 of 178) in the all-epiphyseal group and 7.2% (14 of 195) in the over-the-top group, of which 82% required revision reconstruction. Six patients had overgrowth in the all-epiphyseal group (mean, 1.8 cm) and 1 patient in the over-the-top group (1.5 cm). Three angular deformities occurred, all of which were in the over-the-top group. Both physeal-sparing ACL reconstruction techniques are successful. Overgrowth was more common in the all-epiphyseal group and angular deformity in the over-the-top group. Rerupture rates were similar between the groups. The authors recommend standardization of skeletal age assessment and baseline lower extremity alignment films.

Use of a Modified All-Epiphyseal Technique for Anterior Cruciate Ligament Reconstruction in the Skeletally Immature Patient

Background:

Multiple surgical approaches have been described for the management of anterior cruciate ligament (ACL) tears in skeletally immature patients.

Purpose:

To provide a detailed description of a modified all-epiphyseal ACL reconstruction and report early outcomes and complications with this new technique.

Study Design:

Case series; Level of evidence, 4.

Methods:

A retrospective review of all skeletally immature patients undergoing ACL reconstruction via a modified all-epiphyseal technique prior to July 2015 was performed. Skeletally immature male patients with a bone age of 8 to 15 years and female patients with a bone age of 8 to 12 years were selectively indicated for this procedure. The surgical technique involved an all-epiphyseal femoral tunnel drilled parallel and distal to the physis as well as an all-epiphyseal tibial tunnel. Both tunnels were placed in the anatomic footprint of the ACL. Tibial fixation was achieved first with a suspensory cortical fixation device followed by fixation on the femur with an interference screw.

Results:

During the study period, 30 patients with a mean bone age of 11.8 years underwent ACL reconstruction with this physeal-sparing technique; 26 patients (87%) achieved a minimum follow-up of 2 years. At final follow-up, the mean Lysholm score, Single Assessment Numeric Evaluation score, patient satisfaction, return-to-sport rate, and Tegner activity score were 93, 89, 9.2, 94%, and 7.6, respectively. Four graft failures (15%) and 3 (12%) contralateral ACL tears were identified. One patient was noted to have a 12-mm leg-length discrepancy at final follow-up, which required no additional treatment. No other leg-length discrepancies or angular deformities were identified.

Conclusion:

The modified all-epiphyseal ACL reconstruction technique achieved good functional outcomes, a high rate of return to sport, low failure rates, and low physeal injury rates at a mean follow-up of 3.2 years. Skeletally immature patients with an ACL tear requiring reconstruction pose a unique challenge for sports medicine clinicians. While several previous approaches have been described for this patient population, the proposed benefits of this new technique are that it is anatomic, it is physeal sparing, it uses osseous tunnels, and it provides good initial graft fixation strength.