Challenges in the Management of Anterior Cruciate Ligament Ruptures in Skeletally Immature Patients

Global overview of anterior cruciate ligament reconstruction in children and adolescents over the past 20 years: a bibliometric analysis

OBJECTIVES

The objectives of this paper is to conduct a bibliometric analysis to examine the research status and development trend of anterior cruciate ligament injury and reconstruction in children and adolescents over the past 20 years.

DESIGN

Descriptive Research.

METHODS

This study obtained information regarding studies on Anterior Cruciate Ligament Reconstruction in Children and Adolescents from the Web of Science Core Collection database. Visual and bibliometric analysis were conducted using VOSviewer, Origin 2022, Pajek64 5.18and Excel 2019. These analytic tools facilitated the analysis of various aspects, including countries/regions, institutions, authors, journals and keywords related to the research.

RESULTS

From 2003 to 2023, a total of 1328 articles were retrieved in WOS, and 637 articles were selected by two authors. The most productive institutions are Childrens Hosp Philadelphia, Kocher, ms. Their articles have the highest number of publications and citations. The American journal of sports medicine is the most frequently cited journal for articles on anterior cruciate ligament reconstruction in children and adolescents. The most common keywords used in these articles were "anterior cruciate ligament reconstruction", "injury, children, adolescent", and "skeletally immature patients".

CONCLUSIONS

This study provides valuable insights into the research focus of anterior cruciate ligament reconstruction in children and adolescents. In recent years, there has been significant attention paid to areas of "the return to sport, re-repture rate and functional recovery after anterior cruciate ligament reconstruction" in this specific population. These aspects have emerged as key directions for future research in this field.

Editorial Commentary: Personalized Anterior Cruciate Ligament Reconstruction and Rehabilitation Mitigate Postoperative Arthrofibrosis: Prevention Is the Best Approach

Arthrofibrosis after anterior cruciate ligament reconstruction can become a major complication requiring surgical intervention. The reported incidence approximates 8% but varies widely (2%-35%) and, as not all patients require surgery, may be underreported. Several risk factors are involved. Female sex, older age, surgery within the first month after injury, and meniscus repair are consistently associated with increased risk. Other factors include graft size and type, concomitant procedures, use of anticoagulants, and genetic factors. By identifying risk factors, we can modify our surgical technique and rehabilitation to meet each patient's needs with fewer complications.

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.

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.

LigaNET: A multi-modal deep learning approach to predict the risk of subsequent anterior cruciate ligament injury after surgery

Anterior cruciate ligament (ACL) injuries are a common cause of soft tissue injuries in young active individuals, leading to a significant risk of premature joint degeneration. Postoperative management of such injuries, in particular returning patients to athletic activities, is a challenge with immediate and long-term implications including the risk of subsequent injury. In this study, we present LigaNET, a multi-modal deep learning pipeline that predicts the risk of subsequent ACL injury following surgical treatment. Postoperative MRIs (n=1,762) obtained longitudinally between 3 to 24 months after ACL surgery from a cohort of 159 patients along with 11 non-imaging outcomes were used to train and test: 1) a 3D CNN to predict subsequent ACL injury from segmented ACLs, 2) a 3D CNN to predict injury from the whole MRI, 3) a logistic regression classifier predict injury from non-imaging data, and 4) a multi-modal pipeline by fusing the predictions of each classifier. The CNN using the segmented ACL achieved an accuracy of 77.6% and AUROC of 0.84, which was significantly better than the CNN using the whole knee MRI (accuracy: 66.6%, AUROC: 0.70; P<.001) and the non-imaging classifier (accuracy: 70.1%, AUROC: 0.75; P=.039). The fusion of all three classifiers resulted in highest classification performance (accuracy: 80.6%, AUROC: 0.89), which was significantly better than each individual classifier (P<.001). The developed multi-modal approach had similar performance in predicting the risk of subsequent ACL injury from any of the imaging sequences (P>.10). Our results demonstrate that a deep learning approach can achieve high performance in identifying patients at high risk of subsequent ACL injury after surgery and may be used in clinical decision making to improve postoperative management (e.g., safe return to sports) of ACL injured patients.

All-Epiphyseal Anterior Cruciate Ligament Repair Using Suture Ring Device in the Skeletally Immature Patient

Anterior cruciate ligament (ACL) tears in pediatric patients pose distinct challenges in management, especially in patients with open distal femoral and proximal tibial physes. There are a variety of contemporary reconstruction techniques that attempt to address these challenges. However, with the resurgence of ACL repair in the adult population, it has become apparent that the pediatric patient may also benefit from primary ACL repair rather than reconstruction. ACL repair is a procedure performed to treat ACL tears that avoids the donor-site morbidity seen with ACL reconstruction using autograft. We describe a surgical technique involving FiberRing sutures (Arthrex, Naples, FL) and TightRope-internal brace fixation (Arthrex) for ACL repair with all-epiphyseal fixation in the pediatric patient. The FiberRing is a knotless, tensionable suture device that can be used to stitch the torn ACL and coupled with the TightRope and internal brace to fix the ACL.

Paediatric reference anatomy for ACL reconstruction and secondary anterolateral ligament or lateral extra-articular tenodesis procedures

OBJECTIVES

For iliotibial band (ITB) lateral extra-articular tenodesis or anterolateral ligamentous/capsular reconstruction with anterior cruciate ligament reconstruction, a clear understanding of the referenced anterolateral knee anatomy is critical-especially given the risk of injury to the physis or key anterolateral structures in the paediatric population, which is at high-risk for primary and secondary anterior cruciate ligament injury. The purpose of this study was to quantitatively assess the anatomy of the knee physes, paediatric lateral collateral ligament (LCL) origin, popliteus origin and ITB tibial insertion.

METHODS

Nine paediatric cadaveric knee specimens with average age 4.2 years (range 2 months-10 years) underwent dissection to identify the LCL's and popliteus' femoral origins and the ITB's tibial insertion. Metallic marking pins demarcated precise anatomic attachment sites, and subsequent computerised tomography scans enabled quantified measurements among them.

RESULTS

LCL & Popliteus: On the femur, the popliteus origin lay consistently deep to the LCL and inserted both distally and anteriorly to the LCL, a mean distance of 4.6 mm (range 1.9-7.6; standard deviation 2.0). From the joint line, the LCL lay a mean distance of 12.5 mm proximally while the popliteus measured a mean of 8.2 mm. Both were consistently distal to the physis. The LCL was a mean distance of 4.4 mm (range 1.0-9.5) and the popliteus was a mean distance of 8.2 (range 1.7-12.5) from the physis. ITB insertion: The ITB insertion at Gerdy's tubercle had an average footprint measuring 28.2 mm² (range 10.3-58.4) and the ITB centre lay proximal to the physis in 6 specimens (mean age 4.2 years, median 2.5 years) and distal in 3 specimens (mean age 1.5 years, median 4 months). Mean distance from the footprint centre to the physis was 1.6 mm proximal (range 7.1 proximal - 2.2 distal).

CONCLUSION

This study describes relative and quantitative positions of the femoral LCL and popliteus origins and tibial ITB attachment and their respective physeal relationships. Knowledge of paediatric anterolateral knee anatomy will help guide essential future research and procedures providing extra-articular anterolateral rotatory stabilisation and may help reduce iatrogenic physeal injury risk.

LEVEL OF EVIDENCE

N/A (descriptive anatomic study).

The Spectrum of Anterior Cruciate Ligament Reconstruction Options for the Pediatric and Adolescent Patient: A Narrative Review

As youth sports participation has increased in recent years, injuries to the anterior cruciate ligament (ACL) have become increasingly common in pediatric patients. Historically, ACL reconstruction was delayed in pediatric patients to avoid physeal damage with the potential for leg-length discrepancy or angular deformity. Current research shows that delaying reconstruction or choosing nonoperative management is associated with increased rates of meniscal and chondral injuries, persistent knee instability, and low rates of return to previous activity. Early ACL reconstruction using techniques to avoid physeal growth disturbance is now widely accepted among physicians. The purpose of this review was to describe the pediatric ACL in terms of the relevant anatomy and biomechanics, physical examination, and diagnostic imaging. In addition, the importance of skeletal age and possible physeal injury is discussed in the context of ACL reconstruction options by skeletal age and remaining growth potential.

Early Identification of Arthrofibrosis in Adolescents Following Anterior Cruciate Ligament Reconstruction Is Associated With the Need for Subsequent Surgery: A Matched Case-Control Study

PURPOSE

To identify the postoperative characteristics associated with the need for subsequent surgical intervention in pediatric anterior cruciate ligament reconstruction (ACLR).

METHODS

Patients ≤18 years old who received operative treatment for arthrofibrosis following ACLR versus age- and sex-matched controls with a satisfactory postoperative course were retrospectively reviewed. The range of knee motion preoperatively and at each postoperative visit was recorded. Based on the typical post-operative protocols, visits were categorized into 3 groups: first (first 4 weeks), second (weeks 5-8), and third (weeks 9-16) visits. The deficit in the total arc of range of motion (ROM) in the operative knee relative to the nonoperative knee and the change in ROM between visits were compared. Receiver operating characteristic analysis was performed to determine the time point in which a diagnosis of arthrofibrosis could be predicted with the greatest accuracy.

RESULTS

In total, 18 patients with arthrofibrosis (mean age 14.2 ± 2.7 years, 9 male) and 36 control patients were included in the final analysis. Arthrofibrosis patients had significantly larger ROM deficits at all visits, 93° vs 69° for the first, 69° vs 24° for the second, and 56° vs 2º for the third, compared with controls (P < .001 for all). Pairwise comparisons showed that in arthrofibrosis cases, the total ROM did not change significantly between the second and third visits (P = .77), contrary to the controls. Receiver operating characteristic analysis revealed that the total ROM deficit of 50.7° at the second postoperative visit is 89% sensitive and 92.5% specific for development of arthrofibrosis.

CONCLUSIONS

We found that patients who go on to need manipulation of the knee under anesthesia/arthroscopic lysis of adhesions do not experience a significant improvement in ROM after the first 5-8 weeks, and that a ROM deficit of >50° at the 5- to 8-week mark postoperatively, is associated with ultimately needing operative intervention for arthrofibrosis. Based on these findings, it may be appropriate to intervene earlier if a patient still has a ROM deficit exceeding 50° by the second postoperative month.

LEVEL OF EVIDENCE

Level III, retrospective comparative prognostic trial.

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.

Elevated BMI increases concurrent pathology and operative time in adolescent ACL reconstruction

PURPOSE

The purpose of this study was to (1) report on the incidence of concurrent surgical pathology at the time of adolescent ACL reconstruction, (2) evaluate patient risk factors for concurrent pathology, and (3) measure the effect of BMI on operating room (OR) time.

METHODS

A retrospective analysis of the NSQIP database for the years 2005-2017 was conducted. Nine-hundred and seventeen patients 18 years of age and younger who underwent ACL reconstruction (ACLR) were identified using CPT code 29888 and patients undergoing surgery for multi-ligamentous knee injuries were excluded. The mean patient age was 17.6 years (range 14-18, standard deviation 0.52) and consisted of 546 males (59.5%) and 371 females (40.5%). Logistic regression was used to assess the relationship between BMI and additional CPT codes for internal derangement at the time of surgery. Internal derangement was defined as any procedure for the treatment of a meniscal tear, chondral lesion, or loose body removal. Linear regression analysis was then performed to evaluate the effect of BMI on operative time.

RESULTS

43.7% of patients undergoing ACLR required an associated procedure for internal derangement. Additionally, the risk of requiring additional procedures for internal derangement increased by 3.1% per BMI point. BMI was also predictive of operative time, independent of the number of additional procedures. Specifically, the operative time increased by nearly one minute for every point increase in BMI (58.0 s).

CONCLUSIONS

Adolescent patients with an elevated BMI were much more likely to require additional surgical procedures for internal derangement at the time of ACL reconstruction. Additionally, BMI was a significant predictor for longer operative times.

LEVEL OF EVIDENCE

Level III.

Sociodemographic Factors Associated With Decreased Compliance to Prescribed Rehabilitation After Surgical Treatment of Knee Injuries in Pediatric Patients

Background:

Rehabilitation is an important component of care in postsurgical knee patients, especially as it pertains to return to preinjury activity level. Despite the established significance of rehabilitation in improving outcomes after certain surgical procedures, there is a lack of investigation into compliance rates and factors that affect compliance in pediatric patients.

Purpose/Hypothesis:

The purpose of this study was to evaluate sociodemographic factors associated with noncompliance in pediatric patients after knee surgery to characterize health disparities in this population. Our hypothesis was that certain sociodemographic factors would be associated with decreased compliance.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A retrospective review of medical records was used to gather data on compliance rate, demographics, and socioeconomic factors for pediatric patients undergoing rehabilitation after knee surgery. Compliance rate was determined by counting the total scheduled appointments, cancellations, and no-shows (defined as visits for which patients did not show up and did not provide notification of cancellation). Various types of knee injuries were included in this study. Data were evaluated using bivariate analyses in addition to hierarchical linear and binary logistic regression to assess for associations between sociodemographic factors and compliance rate.

Results:

Our total sample size was 186 patients. When compared with patients from non–single-parent households, patients from single-parent households were found to have a lower rate of physical therapy compliance (72.2% vs 80.1%; P < .001), were less likely to reach the 85% compliance threshold (9.1% vs 42.4%; P < .001), and had an increased amount of cancellations and no-shows (16.7 vs 11.7 visits; P = .02). Although a small sample size, Hispanic/Latino patients were shown to have a lower achievement of the 85% compliance threshold compared with non-Hispanic/Latino patients (0% vs 38.2%; P = .04). Increased distance from the rehabilitation clinic was associated with lower achievement of the 85% compliance threshold (P = .033).

Conclusion:

Overall, there were several significant demographic and socioeconomic variables associated with rehabilitation compliance, specifically single-parent status, distance to rehabilitation clinic, and ethnicity. These results suggest potential predictors of decreased compliance that warrant prospective investigation.

All Inside Intraepiphyseal ACL Reconstruction Using Flexible Curved Instrumentation and Intraoperative Fluoroscopy in a Skeletally Immature Patient

Case

A 13-year-old skeletally immature female presenting with an anterior cruciate ligament (ACL) rupture after a noncontact injury was treated with an intraepiphyseal ACL reconstruction. Flexible instrumentation was utilized to drill a femoral tunnel with an anatomic starting point, with a trajectory that curved inferolaterally away from the physis. At three years postoperatively, she had returned to her preinjury functioning and did not display any lower limb length growth abnormalities.

Conclusions

The novel application of curved guides and flexible instruments, with intraoperative fluoroscopy, facilitated growth plate avoidance and a successful outcome of ACL reconstruction in a skeletally immature patient.

Paediatric anterior cruciate ligament injury

The number of paediatric anterior cruciate ligament injuries is rising at a greater rate than in the adult population, as a result of the increased participation of children and adolescents in sports. This review explores the key presentations, diagnostic and management plans, and prevention methods associated with paediatric anterior cruciate ligament injuries. This injury presents as an acute pop and effusion, with limitations in gait, and can be extremely debilitating. Clinical examination and magnetic resonance imaging are used to diagnose the injury. The pivot shift and Lachman test remain the most valid exams when suspecting an anterior cruciate ligament tear. Management of the injury can be surgical or non-surgical depending on the severity of the tear and associated injuries. The surgical approach chosen is determined by the patient's Tanner classification, considering potential damage to the physes of the bone. Management plans should include rehabilitation consisting of strength, proprioception and neuromuscular training, to maximise the patient's recovery. Injury prevention programmes, consisting of strength training and neuromuscular training, should be followed by young athletes to reduce anterior cruciate ligament injuries. Compliance and earlier implementation coupled with an understanding of the biomechanics of anterior cruciate ligament injuries and verbal feedback maximise the benefit of neuromuscular training.

Risk Factors for Failure After Anterior Cruciate Ligament Reconstruction in a Pediatric Population: A Prediction Algorithm

Background:

Anterior cruciate ligament reconstruction (ACLR) in pediatric patients is becoming increasingly common. There is growing yet limited literature on the risk factors for revision in this demographic.

Purpose:

To (1) determine the rate of pediatric revision ACLR in a nationally representative sample, (2) ascertain the associated patient- and injury-specific risk factors for revision ACLR, and (3) examine the differences in the rate and risks of revision ACLR between pediatric and adult patients.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

The PearlDiver patient record database was used to identify adult patients (age ≥20 years) and pediatric patients (age <20 years) who underwent primary ACLR between 2010 and 2015. At 5 years postoperatively, the risk of revision ACLR was compared between the adult and pediatric groups. ACLR to the contralateral side was also compared. Multivariate logistic regression was used to determine the significant risk factors for revision ACLR and the overall reoperation rates in pediatric and adult patients; from these risk factors, an algorithm was developed to predict the risk of revision ACLR in pediatric patients.

Results:

Included were 2055 pediatric patients, 1778 adult patients aged 20 to 29 years, and 1646 adult patients aged 30 to 39 years who underwent ACLR. At 5 years postoperatively, pediatric patients faced a higher risk of revision surgery when compared with adults (18.0 % vs 9.2% [adults 20-29 years] and 7.1% [adults 30-39 years]; P < .0001), with significantly decreased survivorship of the index ACLR (P < .0001; log-rank test). Pediatric patients were also at higher risk of undergoing contralateral ACLR as compared with adults (5.8% vs 1.6% [adults 20-29 years] and 1.9% [adults 30-39 years]; P < .0001). Among the pediatric cohort, boys (odds ratio [OR], 0.78; 95% CI, 0.63-0.96; P = .0204) and patients >14 years old (OR, 0.62; 95% CI, 0.45-0.86; P = .0035) had a decreased risk of overall reoperation; patients undergoing concurrent meniscal repair (OR, 1.84; 95% CI, 1.43-2.38; P < .0001) or meniscectomy (OR, 2.20; 95% CI, 1.72-2.82; P < .0001) had an increased risk of revision surgery. According to the risk algorithm, the highest probability for revision ACLR was in girls <15 years old with concomitant meniscal and medial collateral ligament injury (36% risk of revision).

Conclusion:

As compared with adults, pediatric patients had an increased likelihood of revision ACLR, contralateral ACLR, and meniscal reoperation within 5 years of an index ACLR. Families of pediatric patients—especially female patients, younger patients, and those with concomitant medial collateral ligament and meniscal injuries—should be counseled on such risks.

Complications and Controversies in the Management of 5 Common Pediatric Sports Injuries

Growing participation in sports among children, along with increasingly intense training regimens, has contributed to an increasing rate of sports-related injuries. Despite the similarities to adult sports injuries, pediatric patients have distinctive injury patterns because of the growing physis and therefore necessitate unique treatment algorithms. Caring for these injured children requires in-depth knowledge of not only pediatric injury patterns, but also the scope of age-specific treatments, the associated complications, and the controversies. When treating motivated pediatric athletes, one must be able to strike a delicate balance between patients' eagerness to return to sport and the need to ensure their long-term health and function. Knowledge of controversies and complications will help both patients and physicians make informed decisions about how best to restore pediatric athletes back to health.

Anterior Cruciate Ligament Injuries in Skeletally Immature Patients: A Meta-analysis Comparing Repair Versus Reconstruction Techniques

BACKGROUND

Anterior cruciate ligament (ACL) surgery remains challenging in the skeletally immature patient. Despite the widespread use of physeal-sparing reconstruction techniques, there has been renewed interest in the ACL repair. The purpose of this study was to systematically review the literature to better understand outcomes following all-epiphyseal (AE) reconstruction to extraphyseal reconstruction, while also evaluating ACL repair outcomes in skeletally immature patients.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, all studies in the literature from January 1970 to August 2019 reporting on skeletally immature patients undergoing ACL surgery were identified. Inclusion criteria were pediatric patients with open physes indicative of skeletal immaturity sustaining complete ACL ruptures treated with AE reconstruction, extraphyseal reconstruction or ACL repair. Chronologic age, bone age, postoperative outcomes scores, return to sport rate, and the incidence of complications, namely reruptures, were analyzed.

RESULTS

A total of 14 studies comprising 443 patients were identified. No significant difference in chronologic age or postoperative outcome scores at final follow-up were appreciated between patients undergoing AE versus extraphyseal reconstruction. Return to activity rate was significant greater following extraphyseal reconstruction when compared with AE reconstruction. The incidence of any limb-length discrepancies and limb discrepancies measuring ≥10 mm were significant higher following AE reconstruction, while rerupture rates were more common following AE reconstruction.

CONCLUSIONS

Patients undergoing AE reconstruction possessed significantly lower return to activity rates, higher incidences of limb-length discrepancies and more commonly experienced ACL reruptures when compared with patients undergoing extraphyseal reconstruction. Further investigations analyzing results following ACL repair in skeletally immature patients are warranted to allow for the comparison of outcomes with current physeal-sparing reconstruction techniques.

LEVEL OF EVIDENCE

Level IV-systematic review-therapeutic study.

Paediatric proximal ACL tears managed with direct ACL repair is safe, effective and has excellent short-term outcomes

PURPOSE

Anterior cruciate ligament (ACL) surgery in the paediatric population has long been a challenge. Non-operative treatment will result in persistent instability which can lead to chondral and meniscal injuries. The results of primary open ACL repair are poor. Concerns of growth plate disturbance with transphyseal techniques and issues with relatively small-diameter grafts in Tanner 1 and 2 patients, which are inadequate, have contributed to these challenges. With advancing instrumentation, there is renewed interest in ACL repair. The minimally invasive approach of arthroscopic primary ACL repair retains the native ligament. The objective and subjective outcomes at 2 years are presented.

METHODS

Paediatric patients, less than 16 years of age, presenting acutely with complete proximal ACL ruptures underwent direct arthroscopic ACL repair, reinforced by a temporary internal brace, which was subsequently removed after 3 months. Patient-reported outcome measures including the Lysholm, Tegner and KOOS scores were collected at 6 months, 1 year and 2 years post-operatively.

RESULTS

Twenty patients (age 6-16) completed data at 2 years post-operatively. There were no failures, no complications and no growth disturbance out to 2 years. The 2-year postoperative outcomes; Lysholm 95 (90-100), Tegner 7 (6-10), KOOS-Child 96.5 (88.9-100) demonstrated statistically significant improvements following surgery (p < 0.001). Objective measurements with an accelerometer did not demonstrate any significant side-to-side difference.

CONCLUSION

ACL repair for proximal ACL tears in the paediatric population demonstrates the potential for excellent outcomes at short-term follow-up. This presents an attractive alternative to ACL reconstruction when an adequate ACL remnant permits direct repair. Our results demonstrate that paediatric ACL repair is safe and effective.

Contralateral Anterior Cruciate Ligament Injuries Following Index Reconstruction in the Pediatric Athlete

PURPOSE OF REVIEW

The purpose of this review is to discuss relevant anatomy and pathoanatomy in the knee following anterior cruciate ligament reconstruction, risk factors for contralateral ACL tear, and mechanisms of contralateral injuries in the pediatric population.

RECENT FINDINGS

Contralateral ACL rupture rates following ACL reconstruction (ACLR) range from 4% to 42%. Pediatric patients show increased risk compared with adults, likely due to inherent anatomical differences along with biomechanical and neuromuscular changes that occur in both the operative and contralateral knees following index ACLR. Pediatric athletes who return to sport more quickly have been found to be at increased risk for contralateral tears, as have athletes who participate in cutting and pivoting sports. Contralateral tears tend to occur via non-contact mechanisms. Pediatric patients are at increased risk of contralateral ACL injury following index ACL reconstruction compared with adults. Further study is warranted to determine appropriate biologic, functional, and rehabilitative parameters gauged toward preventing contralateral ACL tear while minimizing time lost from sport.

Physeal Sparing Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients Bridging the Tibial Physis With Two Divergent Tunnels

A technique for anterior cruciate ligament (ACL) reconstruction in patients with open physis is presented. The patient is positioned supine with the knee flexed 90°. After intraarticular injuries are addressed, an autologous hamstring graft is harvested and prepared using a suspension device attached in its expansion device. All-epiphyseal femoral and tibial tunnels of the same diameter of the graft are created; both of them are drilled in an outside-in direction, sparing the physis under radioscopic control. A second divergent tibial tunnel of the same diameter of the graft, distal to the physis, is created in an outside-in, mediolateral, and craniocaudal direction, leaving a 1-cm bone bridge between the 2 tibial tunnels. The graft is passed through the all-epiphyseal tunnels, from femoral to tibial, and pulled until the suspension device leans on the lateral femoral cortex. The graft is passed through the second divergent tibial tunnel and fixed in it with an interference screw to move the pressure away from the physis.

Over-the-top ACL reconstruction restores anterior and rotatory knee laxity in skeletally immature individuals and revision settings

PURPOSE

To investigate the objective outcomes following anterior cruciate ligament reconstruction (ACLR) with the over-the-top (OTT) technique.

METHODS

Thirty-five ACL-deficient patients with mean follow-up of 2.2 years were retrospectively reviewed. This included 14 skeletally immature individuals (age: 14 ± 1 years) who underwent primary OTT ACLR (adolescent group) and 21 skeletally mature individuals (age: 25 ± 8 years) who underwent OTT revision ACLR (revision group). The tibial tunnel was created at the anatomic position for all cases. No lateral extra-articular tenodesis was performed. Before and after surgery, the side-to-side difference (SSD) in anterior laxity was measured using KT-1000 arthrometer. Lachman and pivot-shift tests were assessed according to IKDC grade. The graft failure rate was assessed.

RESULTS

The post-operative SSD in anterior laxity was significantly reduced in the adolescent (pre-op, 3.9 ± 1.8 mm; post-op, 1.2 ± 0.8 mm; p = 0.040) and revision groups (pre-op, 4.2 ± 1.7 mm; post-op, 1.2 ± 1.4 mm; p < 0.001). Postoperative knee laxity measured by Lachman and pivot-shift tests were also significantly improved in both groups. Graft rupture occurred in two patients in the adolescent group (14.3%), and one patient in the revision group (4.8%).

CONCLUSION

ACLR with the OTT technique restored anterior and rotatory knee laxity in skeletally immature individuals and in revision settings. This one-step procedure may be a good option for skeletally immature individuals and revision settings.

LEVEL OF EVIDENCE

IV.

Paediatric and adolescent anterior cruciate ligament reconstruction surgery

Aims

Anterior cruciate ligament (ACL) surgery in children and the adolescent population has increased steadily over recent years. We used a national database to look at trends in ACL reconstruction and rates of serious complications, growth disturbance, and revision surgery, over 20 years.

Methods

All hospital episodes for patients undergoing ACL reconstruction, under the age of 20 years, between 1 April 1997 and 31 March 2017, were extracted by procedure code from the national Hospital Episode Statistics (HES). Population standardized rates of intervention were determined by age group and year of treatment. Subsequent rates of serious complications including reoperation for infection, growth disturbance (osteotomy, epiphysiodesis), revision reconstruction, and/or contralateral ACL reconstruction rates were determined.

Results

Over the 20 year period, 16,125 ACL reconstructions were included. The mean age of patients was 16.9 years (SD 2.0; 27.1% female, n = 4,374/16,125). The majority of procedures were observed in the 15 to 19 years age group. The rate of ACL reconstruction increased 29-fold from 1997 to 1998, to 2016 to 2017. Within 90 days of ACL reconstruction, the rate of reoperation for infection was 0.31% (95% confidence interval (CI) 0.23 to 0.41, n = 50/16,125) and the rate of pulmonary embolism was 0.037% (95%.CI 0.014 to 0.081, n = 6/16,125). Of those with minimum five-year follow-up following ACL reconstruction (n = 7,585), 1.00% of patients subsequently underwent an osteotomy (95% CI 0.79 to 1.25, n = 76/7,585), 0.09% an epiphysiodesis (95% CI 0.04 to 0.19, n = 7/7,585), 7.46% revision ACL reconstruction (95% CI 6.88 to 8.08, n = 566/7,585), and 6.37% contralateral ACL reconstruction (95% CI 5.83 to 6.94, n = 483/7,585).

Conclusion

Rates of paediatric and adolescent ACL reconstruction have increased 29-fold over the last 20 years. Despite the increasing rate in the younger population, the risk of serious complications, including further surgery for growth disturbance is very low. The results of our study provide a point of reference for shared decision making in the management of ACL injury in the paediatric and adolescent population. Cite this article: Bone Joint J 2020;102-B(2):239–245.

Arthroscopic Repair of Proximal Posterior Cruciate Ligament Injuries in Pediatric Patients

A renewed interest in arthroscopic knee ligament repair is emerging as a result of diagnostic and technical improvements. In pediatric patients with posterior cruciate ligament (PCL) injury, surgical reconstruction is rarely considered as an option because of the risk of iatrogenic physeal injury. In this Technical Note, we describe an arthroscopic surgical repair technique of PCL proximal avulsions in pediatric patients. The main reasons to consider arthroscopic PCL repair in this population include minimal surgical morbidity, preservation of the complex biomechanical properties of the native ligament, the small diameter of the bone tunnels, the physeal respecting nature of the procedure, the absence of graft harvesting, and the absence of fixation devices. The indications for this technique are limited to patients with an acute proximal PCL avulsion. Investigation performed from at Centre Orthopédique Santy, FIFA Medical Center of Excellence, Lyon, France.

Treatment of ACL Tears in the Skeletally Immature Patient

The understanding and treatment of anterior cruciate ligament tears in skeletally immature patients continues to evolve. While conservative management was a mainstay of treatment, poor outcomes have led to several surgical techniques aimed at stabilizing the knee, optimizing outcome, and minimizing the chance of growth disturbance. Current techniques have, in large part, accomplished these goals but challenges remain. Looking to the future, different graft options, primary repair techniques, and rigorous prospective studies will help improve outcomes for this challenging patient population.