Complications after epiphyseal reconstruction of the anterior cruciate ligament in prepubescent children

ACL Reconstruction in Skeletally Immature Athletes: Current Concepts

ACL injury in skeletally immature patients remains a debatable topic in terms of its management, surgical choices and rehabilitation. The treatment preferences vary across the globe. Children are not little adults in terms of their physiology and anatomy. Hence, contemporary treatment inferred from the adult population does not give the same outcomes in pediatric patients. An in-depth study of specific challenges and difficulties is warranted to optimize the treatment strategies to cater to this group of patients. There is a paucity of literature giving long-term follow-up of ACLR in skeletally immature patients and no standardized guidelines are present for managing this group of patients. The authors have tried to summarize the current concepts for managing ACL injuries in skeletally immature patients through this article. Multiple lacunae and controversies exist in the knowledge regarding the optimum treatment of pediatric patients with ACL injuries who are comparatively more prone to ACL tears than their adult counterparts. Identifying the best mode of management of ACL tears in these skeletally immature patients is necessary. Level of evidence: Level IV.

Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients Using an All-Epiphyseal Technique: A Prospective Cohort Study

Background

Transphyseal techniques are the most commonly used for anterior cruciate ligament (ACL) reconstruction in children. To mitigate the risk of growth disturbance, the tunnels should be positioned as vertically and centrally as possible in relation to the physis, potentially compromising the anatomic orientation of the graft and, therefore, its isometry. A graft rupture is frequent in this age group. Even though all-epiphyseal techniques have not clearly demonstrated better isometry, the authors propose an epiphyseal technique that aims for favorable anatomy, and therefore isometry, while avoiding physeal damage in young children with ACL ruptures.

Purpose

To present the results of a modified all-epiphyseal technique in prepubertal patients, evaluating knee function, graft survival, and joint and growth protection.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 74 skeletally immature patients with a traumatic ACL rupture underwent a physeal preserving technique using a semitendinosus-gracilis tendon graft fixed with intra-epiphyseal resorbable interference screws in the femur and tibia, along with associated minimal notchplasty. Preoperative, intraoperative, and postoperative assessments included clinical knee stability and meniscal status, magnetic resonance imaging, isometry measurements, comparative laximetry measurements with stress radiography using the Lerat method, full-length standing radiography, measurements of the axes of the lower limbs, Tegner and Lysholm scores, and patient satisfaction.

Results

From 2004 to 2014, a total of 74 patients met our inclusion criteria and were followed up for a mean of 4.1 years (range, 2-7 years). Of these patients, 91.9% had an excellent/good postoperative Lysholm score, with similar preoperative and postoperative Tegner activity scores. Intraoperative isometry showed an intratunnel graft excursion <3 mm during extension in 95.9% of cases. Abnormal clinical laxity was observed in 4.1% at final follow-up, with an improvement in side-to-side laxity of 4.8 mm. There were 3 patients who experienced graft failure, with the salvage procedure employing a transphyseal technique in 1 patient. Meniscal tears occurred in 27.0%, with concomitant repair yielding a healing rate of 87.5%. No physeal alterations were observed, except for a tendency toward subtle overgrowth in the affected limb. Also, 90.5% of patients were satisfied or very satisfied with the outcome.

Conclusion

The proposed all-epiphyseal technique in skeletally immature patients demonstrated excellent overall results with a low incidence of reruptures and meniscal degeneration, without relevant alterations related to growth.

Midterm Outcomes of Hybrid Transepiphyseal ACL Reconstruction With Soft Tissue Quadriceps Tendon Autograft in Skeletally Immature Athletes

Background

Substantial developments in physeal-sparing surgical techniques for anterior cruciate ligament (ACL) reconstruction (ACLR) have demonstrated safety and efficacy in treating skeletally immature patients. However, outcomes using all-soft tissue quadriceps tendon (QT) autograft in this population are unknown.

Purpose

To evaluate outcomes including return to sport (RTS) and reinjury risk in skeletally immature patients ≥2 years after undergoing hybrid transepiphyseal ACLR using QT autograft.

Study Design

Case series; Level of evidence, 4.

Methods

A consecutive series of skeletally immature patients who underwent primary QT autograft ACLR using a hybrid transepiphyseal technique with ≥2 years of follow-up were retrospectively analyzed. Outcomes included RTS (primary), ability to return to preinjury level of competition, and subsequent ipsilateral/contralateral knee injury (secondary).

Results

A total of 50 patients were identified and contacted, of which 40 (80.0%) (35 male; mean age, 12.6 years [range, 9.4-16.0 years]) completed the survey at 5.7 ± 2.8 years (range, 2.0-11.5 years) postoperation. Of those, 26 (65.0%) were competitive middle/high school athletes and 18 (45.0%) competed in ≥2 sports. At a mean of 10.6 ± 2.3 months (range, 6-17 months) postoperatively, 37 patients (92.5%) returned to unrestricted sports participation, and 35 patients (87.5%) resumed competition at their preinjury level. Five patients required subsequent ipsilateral knee surgery for ACL revision (n = 2; 5.0%), meniscal injury (n = 2; 5.0%), or symptomatic hardware (n = 1; 2.5%) after a mean of 4.4 ± 1.7 years (range, 2.8-7.1 years). Three patients (7.5%) sustained a subsequent contralateral ACL injury, and 1 patient sustained a contralateral posterior cruciate ligament sprain.

Conclusion

Findings of this study suggest that midterm outcomes of patients treated with hybrid transepiphyseal ACLR using QT autograft are promising, with a high and expedited RTS and relatively low graft tear risk.

Allograft versus autograft ACL reconstruction in skeletally immature patients: a systematic review

INTRODUCTION

Anterior cruciate ligament (ACL) injuries in children and adolescents with open physes are common.

AREAS OF AGREEMENT

Evidence of ACL reconstruction using allografts in children with open physes is limited.

AREAS OF CONTROVERSY

Whether the outcomes of ACL allograft reconstruction in children and adolescents with open physes are superior to autograft ACL reconstruction is unclear, with contrasting evidence.

SOURCE OF DATA

In October 2024, the Web of Science, PubMed, and Embase were accessed with no additional filters. Only clinical investigations evaluating ACL reconstruction in children or adolescents with open physes were eligible. Only studies reporting a minimum length of 24 months of follow-up were included.

AREAS TIMELY FOR DEVELOPING RESEARCH

Children who undergo allograft ACL reconstruction demonstrate similar functional outcomes to those who undergo autograft ACL reconstruction. Although allografts allow a faster return to sport, the greater laxity, the reduced activity level, and the higher failure and reoperation rates make their use dubious as a first-choice option for ACL reconstruction in skeletally immature patients.

Bone-patellar tendon-bone, hamstring, and quadriceps tendon autografts for anterior cruciate ligament reconstruction in skeletally immature patients: a systematic review

INTRODUCTION

Historically, anterior cruciate ligament (ACL) ruptures in the paediatric age group were managed conservatively with bracing, casting, activity modification, and physical therapy. However, most of these patients had to reduce their sports activities, and secondary damages to the affected knee were prevalent.

SOURCE OF DATA

Published scientific literature in Embase, Web of Science, PubMed, and Google Scholar databases.

AREAS OF AGREEMENT

ACL reconstruction in children with open physes patients is debated. Any damage to the physes around the knee could lead to growth abnormalities and axial deviation of the knee.

AREAS OF CONTROVERSY

Different grafts are available and suitable for ACL reconstruction in skeletally immature patients; however, which graft performs better remains unclear.

GROWING POINTS

This systematic review compared bone-patellar tendon-bone (BPTB), hamstring tendon (HT), and quadriceps tendon (QT) autografts for ACL reconstruction in skeletally immature patients. The joint laxity, Patient-reported outcome measures (PROMs), return to sport, and complications were compared.

AREAS TIMELY FOR DEVELOPING RESEARCH

In skeletally immature patients, HT, BPTB, and QT autografts for ACL reconstruction yielded good outcomes. Comparative studies are strongly required to establish the most suitable autograft.

The Double-Edged Sword: Anterior Cruciate Ligament Reconstructions on Adolescent Patients-Growth Plate Surgical Challenges and Future Considerations

The management of anterior cruciate ligament (ACL) injuries in pediatric patients presents unique challenges due to the presence of open growth plates in the proximal tibia and distal femur. Delaying ACL reconstruction until skeletal maturity may protect the physes but increases the risk of secondary injuries, such as meniscal tears and chondral damage, due to prolonged joint instability. Conversely, early surgical intervention restores knee stability but raises concerns about potential growth disturbances, including leg-length discrepancies and angular deformities. This narrative review examines current approaches to pediatric ACL management, highlighting the risks and benefits of both conservative and surgical treatments. Additionally, it explores the role of finite element modeling (FEM) as an innovative tool for pre-surgical planning. FEM offers a non-invasive method to optimize surgical techniques, minimize iatrogenic damage to growth plates, and improve patient outcomes. Despite its potential, FEM remains underutilized in clinical practice. This review underscores the need to integrate FEM into pediatric ACL care to enhance surgical precision, reduce complications, and improve long-term quality of life for young patients. By synthesizing available evidence, this review aims to provide clinicians with a comprehensive framework for decision-making and identify future directions for research in pediatric ACL reconstruction.

Disparities in Evaluation, Treatment, and Outcomes of Pediatric Knee Injuries

Similar to other fields, there is growing evidence of disparities in pediatric sports medicine. For children and adolescents with knee injuries, disparities persist along the lines of sex, gender, race, ethnicity, insurance, socioeconomic status, and other determinants. These factors influence the evaluation, treatment, and outcomes for a variety of knee pathologies, including anterior cruciate ligament ruptures, meniscus tears, osteochondritis dissecans, cartilage injuries, and tibial spine fractures. Inequities in care may have long-term functional and psychosocial implications. Additional research is necessary to further elucidate the etiology of these disparities, raise patient and community voices, and design interventions so that equitable care is delivered to every patient.

Technique "without bone tunnels" (Micheli-Kocher) in anterior cruciate ligament reconstruction in growing patients. Surgical details and our experience with 19 cases

BACKGROUND

Given the boom in sports in school age, its intensity and the increase in sports in females, we are experiencing a boom in sports injuries characteristic of "adults" in growing patients, the anterior cruciate ligament being an injury with possible serious consequences.

METHODS

To show the surgical technique "without bone tunnels" by Micheli-Kocher in anterior cruciate ligament reconstruction in growing patients based on our results in 20 patients.

RESULTS

Since 2017 we have performed the technique "without bone tunnels" by Micheli-Kocher in 30 patients, 20 of whom have been followed up for more than 2 years. In our study, we have observed a return to previous sports activity in more than 90% of the patients, with only one patient undergoing reoperation due to a new rupture of the plasty. The results on the IKDC scales show an improvement in mean score from 42 points preoperatively to 84 postoperatively and on the Lysholm scale from 48 preoperatively to 94 postoperatively.

CONCLUSIONS

The technique "without bone tunnels" by Micheli-Kocher is a technique indicated in patients under 12 years of age and Tanner stage 2 or less. It is a technique of moderate complexity with excellent results in recovery from previous sports activity and knee stability.

Combined over-the-top reconstruction with posterolateral bundle remnant re-tensioning in pediatric anterior cruciate ligament reconstruction: A technical note

Epiphyseal injury, particular on femoral side, is a major concern in pediatric anterior cruciate ligament (ACL) reconstruction. Therefore, the over-the-top route (OTTR) method has frequently been selected in pediatric ACL reconstruction, with good clinical results reported. However, a cadaver study reported the inferior rotational stability of the OTTR method to that of anatomical single bundle reconstruction. In recent years, a new method of reconstruction, which involves the remnant being detached, re-tensioned, and re-attached, achieved good short-term results. We developed a surgical method to restore the remnant to the posterolateral (PL) bundle footprint and obtain rotational stability in patients, thereby preserving the remnant. We hypothesized that repairing the residual remnant to the PL bundle footprint in pediatric ACL reconstruction could achieve rotational stability. This report offers the surgical techniques for PL bundle tensioning repair using remnants in the pediatric ACL OTTR procedure.

All-epiphyseal anterior cruciate ligament reconstruction yields superior sports performances than the trans-epiphyseal technique in skeletally immature patients: a systematic review

BACKGROUND

Anterior cruciate ligament (ACL) tears in skeletally immature patients are increasingly common. Evidence comparing the outcomes of all-epiphyseal versus trans-epiphyseal ACL reconstruction in skeletally immature patients is limited, and the current literature could benefit from a comprehensive systematic review. The present study compared all-epiphyseal versus trans-epiphyseal ACL reconstruction in skeletally immature patients. The outcomes of interest were to compare joint laxity, patient-reported outcome measures (PROMs), return to sport, and complications.

METHODS

This study was conducted according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. In November 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar, and Embase. No additional filters were used in the database search. All the clinical studies investigating ACL reconstruction in skeletally immature patients were accessed. Only articles that clearly stated the surgical technique (all- or trans-epiphyseal) were eligible. Only articles with a minimum of 6 months of follow-up were included. Only articles that clearly stated that surgeries were conducted in children with open physis were eligible.

RESULTS

Data from 1489 patients (1493 procedures) were collected, of which 32% (490 of 1489 patients) were female. The mean length of follow-up was 46.6 months. The mean age of the patients was 12.7 years. No difference was found in joint laxity (Table 3): positive pivot shift (P = 0.4), positive Lachman test (P = 0.3), and mean arthrometer laxity (P = 0.1). No difference was found in PROMs (Table 4): International Knee Documentation Committee (IKDC) (P = 0.3), Lysholm (P = 0.4), and Tegner (P = 0.7). The trans-epiphyseal technique was associated with a greater rate of patients unable to return to sports (1% versus 7%, P = 0.0001) and with a longer time to return to sports (7.7 versus 8.6 months, P = 0.01). Though the trans-epiphyseal technique was associated with a lower rate of return to sport, this difference was not statistically significant (P = 0.8). No difference was evidenced in the rate of patients who had reduced their league or level of sports activity (P = 0.6) or in the rate of patients who had returned to their previous league or level of sports activity (P = 0.7). No difference was found in the rate of complication: re-tear (P = 0.8), reoperation (P = 0.7), increased laxity (P = 0.9), and persistent instability sensation (P = 0.3).

CONCLUSION

Trans-epiphyseal ACL reconstruction was associated with a greater rate of patients unable to return to sport and with a longer time to return to sport compared with the all-epiphyseal technique in skeletally immature patients. Level of evidence Level III, systematic review.

Anterior cruciate ligament reconstruction in skeletally immature patients is effective: A systematic review

PURPOSE

The present study evaluated the outcomes of anterior cruciate ligament (ACL) reconstruction in children with open physes. The outcomes of interest were to compare the increase in joint laxity and PROMs from baseline to the last follow-up, the rate and features of the return to sport and the rate of complications.

METHODS

This study was conducted according to the 2020 PRISMA guidelines. In October 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar and Embase. All the clinical studies investigating ACL reconstruction in skeletally immature patients were accessed. Only articles which clearly stated that surgeries were conducted in children with open physis were eligible.

RESULTS

Data from 53 studies (1691 procedures) were collected. 35% (597 out of 1691 patients) were women. The mean length of the follow-up was 44.7 ± 31.3 months. The mean age of the patients was 12.7 ± 1.1 years old. All PROMs significantly improved from the baseline values to those at the last follow-up. The mean time to return to sport was 8.3 ± 1.9 months. 89% (690 out of 771 patients) returned to sports, 15% (109 out of 721 patients) reduced their level of sports activity or league, and 84% (651 out of 771 patients) returned to their previous level of sport. 9% (112 out of 1213) of patients experienced re-tear of the reconstructed ACL, and 11% (75 out of 660) of patients underwent a further ACL reoperation. No patients (0 out of 83) demonstrated increased laxity at the last follow-up, and persistent sensation of instability was reported by 5% (11 out of 235) of patients.

CONCLUSION

ACL reconstruction in skeletally immature patients is effective and safe, and is associated with fast recovery and a high rate of return to sport.

LEVEL OF EVIDENCE

Level IV.

Risk Factors for Ipsilateral Versus Contralateral Reinjury After ACL Reconstruction in Athletes: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) reinjury after ACL reconstruction (ACLR) can occur on the ipsilateral or contralateral side. Limited evidence exists regarding the difference between the incidence of reinjury to either knee, which is important in developing interventions to prevent ACL reinjury.

Purpose

To compare the reinjury rate of the ACL on the ipsilateral side versus the contralateral side in athletes after ACLR and investigate the risk factors that may cause different reinjury rates between the sides.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies that involved ACL reinjury in athletes after ACLR were reviewed. Considering several risk factors, including age and sex, a comparison of ACL reinjury incidence on the ipsilateral and contralateral sides was performed using a meta-analysis.

Results

Of the 17 selected studies, 3 were found to be at high risk of bias, and thus, 14 (n = 3424 participants) studies were included in the meta-analysis. In this athletic population, the contralateral ACL had a significantly higher rupture rate than the ipsilateral graft (risk ratio [RR], 1.41; P < .0001). Female athletes were found to have a greater risk of ACL reinjury on the contralateral versus the ipsilateral side (RR, 1.65; P = .0005), but different results were found in male athletes. (RR, 0.81; P = .21). There was no statistical difference in the incidence rate of ACL reinjury to either side in adolescent athletes (RR, 1.15; P = .28).

Conclusion

The contralateral ACL was more vulnerable to reinjury than the ipsilateral side in athletes after ACLR. Female athletes were more likely to reinjure their contralateral native ACL, while the same trend was not found in their male counterparts. The reinjury rate was comparable in both knees in adolescent athletes.

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.

Various Definitions of Failure Are Used in Studies of Patients Who Underwent Anterior Cruciate Ligament Reconstruction

Purpose

To conduct a literature review to assess the definitions of anterior cruciate ligament reconstruction (ACLR) failure used throughout the orthopaedic literature.

Methods

A systematic search of Embase, Ovid Medline, SPORTDiscus, and Web of Science was conducted by a university librarian to identity level I-IV clinical studies on ACLR failure. Inclusion criteria consisted of patients who underwent ACLR and included a definition of failure of ACLR. Patients who underwent anterior cruciate ligament (ACL) repairs, animal/cadaver studies, review studies, non-English language articles, and non-full text articles were excluded. Failure data were extracted from each study and categorized. Other data that were extracted included follow-up time after ACLR, failure reoperation rate, and failure reoperation procedure. Descriptive statistics was used to analyze the data.

Results

Out of 2,775 studies, 104 (3.75%) met inclusion criteria and were analyzed in this review. The most common definition of ACLR failure included the use of a physical examination, specifically Lachman's test (21/104 [20.2%]), anterior laxity assessment, or a Pivot-Shift test (24/104 [35.2%]) or undergoing or requiring revision ACLR (39/104 [37.5%]). Although some studies used quantitative tests or imaging to help define "failure," others simply defined it as graft rerupture that was otherwise not defined (22/104 [22.5%]). Other common definitions included: the use of imaging (magnetic resonance imaging/radiographs) to confirm graft re-rupture (37/104 [35.6%]), patient-reported outcomes (recurrent instability)/patient reported outcomes measures (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Tegner) (18/104 [17.3%]), and the use of an arthrometer (KT-1000/2000, Rollimeter, or Kneelax) (17/104 [16.3%]). The least common definitions included graft failure or rerupture confirmed by arthroscopy (13/104 [12.5%]) and nonrevision surgery (2/104 [1.0%]). The failure rate of this procedure ranged from 0% to 100% depending on the definition of "failure."

Conclusion

In this study, we found that a variety of definitions of failure are used among studies published in the orthopaedic literature. The most common criteria for failure of ACLR were the results of physical examination tests (35%), the need for undergoing a revision ACLR (36%), and the use of imaging to diagnose the failure (34%). About 17% of studies included in this review used patient-reported outcomes, specifically recurrent instability, or PROMs (IKDC, KOOS, Tegner) in their assessment of failure of ACLR. The least used definitions of "failure" of ACLR included nonrevision ACLR surgery (2%). Although some studies used similar tests or categories in their definition of failure, there were a variety of score and grade cutoff points between them.

Level of Evidence

Level IV, systematic review of Level II-IV studies.

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.

Management of Pediatric Anterior Cruciate Ligament Injuries: A Critical Analysis

» Overall evidence for the treatment of an anterior cruciate ligament (ACL) injury in a pediatric or skeletally immature patient remains lows.» An ACL reconstruction is recommended with concomitant repairable chondral and meniscus injury or with symptoms of persistent instability despite high-quality rehabilitation.» Treatment decision for pediatric ACL reconstruction should use a shared decision-making model weighing the risks and benefits of both a nonoperative vs. surgical treatment.

Leg-Length and Alignment Changes in Children and Adolescents After Transphyseal Anterior Cruciate Ligament Reconstruction With Soft Tissue Graft: Results at 1-Year Follow-up

Background

Growth disturbance to leg length or coronal plane alignment are important considerations in pediatric anterior cruciate ligament (ACL) reconstruction (ACLR).

Purpose/Hypothesis

The purpose of this study was to investigate the lower limb alignment and leg length of pediatric patients preoperatively and at approximately 1 year after transphyseal ACLR. Our hypothesis was that there would be no significant change in leg-length discrepancy (LLD) or operated-side alignment at follow-up.

Study Design

Case series; Level of evidence, 4.

Methods

Data were extracted from the prospective Queensland Children's Hospital Pediatric ACL Injury Registry. Long-leg alignment radiographs were captured preoperatively and at an approximately 12-month postoperative follow-up. Radiographic measures included leg length, LLD (injured minus uninjured leg length), mechanical axis deviation (MAD), mechanical and anatomical lateral distal femoral angle (mLDFA and aLDFA, respectively), and medial proximal tibial angle. We evaluated the effect of time (annual vs baseline) on imaging measurements with analysis of covariance, using the covariates of age, sex, and body mass index.

Results

Data were available for 104 patients, of whom 34 (33%) had >12 months of skeletal growth remaining based on skeletal age. At an average follow-up time of 14.5 months after ACLR, there were no significant differences in mean lower limb alignment or longitudinal growth compared with baseline. However, seven patients demonstrated clinically significant changes to their mechanical axis or LLD (>10 mm change). A subgroup analysis of patients with >12 months of growth remaining (n = 34) demonstrated no statistically significant changes in mean alignment or LLD. Before surgery, LLD was -1.39 mm and the injured limb was in significantly more valgus compared with the uninjured lower limb (mean difference: MAD, 4.79 mm [95% CI, 2.64 to 6.94 mm]; mLDFA, -0.93° [95% CI, -1.29° to -0.57°], and aLDFA, -0.91° [95% CI, -1.31° to -0.50°]).

Conclusion

After ACLR, there were no statistically significant changes in mean alignment or longitudinal growth; however, 7 out of 104 patients (6.7%) demonstrated clinically significant changes in alignment or LLD. Preoperatively, the injured limb was statistically significantly in more valgus compared with the uninjured limb with lateralized MAD.

Overgrowth of long bone in rabbits by growth stimulation through metaphyseal hole creation

Overgrowth of long bones was noted in pediatric patients who underwent anterior cruciate ligament reconstruction. Hyperaemia during creating a metaphyseal hole and the microinstability made by the drill hole may induce overgrowth. This study aimed to determine whether metaphyseal hole creation accelerates growth and increases bone length and compare the effects of growth stimulation between metaphyseal hole creation and periosteal resection. We selected 7- to 8-week-old male New Zealand white rabbits. Periosteal resection (N = 7) and metaphyseal hole creation (N = 7) were performed on the tibiae of skeletally immature rabbits. Seven additional sham controls were included as age-matched controls. In the metaphyseal hole group, the hole was made using a Steinman pin at the same level of periosteal resection, and the cancellous bone beneath the physis was removed by curettage. The vacant space in the metaphysis below the physis was filled with bone wax. Tibiae were collected 6 weeks after surgery. The operated tibia was longer in the metaphyseal hole group (10.43 ± 0.29 cm vs. 10.65 ± 0.35 cm, P = 0.002). Overgrowth was higher in the metaphyseal hole group (3.17 ± 1.16 mm) than in the sham group (- 0.17 ± 0.39 mm, P < 0.001). The overgrowth in the metaphyseal hole group was comparable to that in the periosteal resection group (2.23 ± 1.52 mm, P = 0.287). In rabbits, metaphyseal hole creation and interposition with bone wax can stimulate long bone overgrowth, and the amount of overgrowth is similar to that seen in periosteal resection.

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.

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.

Comparison of clinical outcomes between anterior cruciate ligament reconstruction with over-the-top route procedure and anatomic single-bundle reconstruction in pediatric patients

The purpose of this study is to evaluate the clinical results of over-the-top route (OTTR) reconstruction for pediatric anterior cruciate ligament (ACL) injuries and compare them with results of anatomic single-bundle reconstruction (SBR), which used the bone tunnel technique and was performed early after epiphyseal closure (age ≤15 years). This study included pediatric patients aged 11-15 years who underwent ACL reconstruction. The mean age at surgery was 13.4 years (11-15 years), including 14 men and 29 women. Operative procedures were determined according to growth plate closure. In all cases, the tibial side was reconstructed using a bone tunnel procedure. On the femoral side, we selected the OTTR procedure (group O) with open physis. Where the physis was closed, we selected the anatomical SBR (group B). The clinical results were evaluated with manual examination, the side-to-side difference (SSD) in tibial anterior translation using the Kneelax 3, and knee function score. There were no significant differences in the Lachman and pivot-shift tests, SSD in tibial anterior translation with Kneelax 3, or knee function score between the two groups before or after the surgery. Growth disturbance was not observed on either the femoral or tibial side in group O. The OTTR method provided comparable results with the bone tunnel anatomical method in manual examination, Kneelax 3, and knee clinical function scores, suggesting that the OTTR method is very useful for pediatric ACL reconstructions. Level of evidence: III; retrospective study.

Robot-assisted all-epiphyseal anterior cruciate ligament reconstruction in skeletally immature patients: a retrospective study

PURPOSE

To review a series of adolescent patients with anterior cruciate ligament (ACL) injuries surgically treated with robot-assisted all-epiphyseal ACL reconstruction (ACLR), and to compare with the traditional freehand group.

METHODS

This retrospective clinical study included 16 patients with ACL injuries who underwent ACLR by robot-assisted technique or traditional freehand method from June 2018 to March 2020. All patients were divided into the robot-assisted group (6 patients) or the traditional surgery group (10 patients). The number of intra-operative fluoroscopies, operation time, accuracy of bone tunnel insertions, International Knee Documentation Committee (IKDC) subjective score and ligament laxity testing were recorded in the two groups.

RESULTS

All patients returned for follow-up, at a mean of 31.6 ± 4.5 months after surgery. The average age of the robot-assisted group was 12.2 ± 1.3 years. The number of intra-operative fluoroscopies was 10.9 ± 2.8 in the traditional freehand group, whereas it was only 3.0 ± 0.6 in the robot-assisted group, which was significantly lower (P < 0.05). The operative time in the robot-assisted group was shorter than that in the traditional freehand group (87 ± 10.7 min vs. 126 ± 12.1 min, P < 0.05). The distance between the center of actual insertion and the center of the idea insertion on both femoral and tibial intra-articular bone tunnel were 1.5 ± 0.3 mm and 1.6 ± 0.3 mm for the robot-assisted group and 2.7 mm ± 0.4 mm and 2.4 ± 0.4 mm for the traditional freehand group (P < 0.05). There were no significant differences between the two groups in function recovery at the last follow-up.

CONCLUSIONS

All-epiphyseal ACLR is a technically demanding procedure with a small margin of error. Robot-assisted treatment of ACL injuries in skeletally immature patients is more accurate than traditional freehand method, with shorter operation time and fewer intra-operative fluoroscopies.

Physeal-sparing ACL reconstruction provides better knee laxity restoration but similar clinical outcomes to partial transphyseal and complete transphyseal approaches in the pediatric population: a systematic review and meta-analysis

PURPOSE

The aim of this meta-analysis was to evaluate complete transphyseal (CTP), partial transphyseal (PTP), and physeal-sparing (PS) techniques for anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic literature search of the PubMed, Web of Science, Cochrane Library, and Scopus literature databases was performed on 10.05.2021. All human studies evaluating the outcomes of CTP, PTP, and PS techniques were included. The influence of the selected approach was evaluated in terms of rates of retears, return to previous level of sport competition, IKDC subjective and objective scores, Lysholm score, rate of normal Lachman and pivot-shift tests, limb length discrepancy, and hip-knee angle (HKA) deviation. Risk of bias and quality of evidence were assessed following the Downs and Black checklist.

RESULTS

Forty-nine out of 425 retrieved studies (3260 patients) met the inclusion criteria. The results of the meta-analysis comparing CTP, PTP, and PS approaches for ACL reconstruction in the under 20-year-old population showed a significant difference in terms of differential laxity (CTP 1.98 mm, PTP 1.69 mm, PS 0.22 mm, p < 0.001). No significant differences were seen in terms of growth malalignment, rate of normal Lachman and pivot-shift tests, and rate of normal/quasi-normal IKDC objective score.

CONCLUSIONS

The present meta-analysis found overall similar results with the three ACL reconstruction approaches. The PS technique showed better results in terms of knee laxity than the PTP and CTP approaches, but this did not lead to a significant difference in terms of subjective and objective scores. No clear superiority of one technique over the others was found with respect to re-ruptures, growth disturbances, and axial deviations. While the argument for avoiding growth malalignment does not seem to be a crucial point, the PS technique should be the preferred approach in a young population to ensure knee laxity restoration.

LEVEL OF EVIDENCE

Level III.

Physeal-Sparing Anterior Cruciate Ligament Reconstruction with Iliotibial Band Autograft in the Skeletally Immature Knee

Conventional adult anterior cruciate ligament reconstruction techniques are controversial in skeletally immature patients due to the risk of iatrogenic physeal damage and potential growth disturbance. The physeal-sparing, combined intra- and extra-articular anterior cruciate ligament reconstruction using an autogenous iliotibial band was developed to mitigate this risk in prepubescent, skeletally immature patients, with excellent functional outcomes and a low revision rate. This article describes the surgical details of this reproducible reconstruction technique.

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.

Improved epiphyseal socket placement with intraoperative 3D fluoroscopy: a consecutive series of pediatric all-epiphyseal anterior cruciate ligament reconstruction

PURPOSE

Disturbance of the growth plate during all-epiphyseal anterior cruciate ligament reconstruction (ACLR) socket placement is possible due to the undulation of the distal femoral physis and proximal tibial physis. Therefore, it is important to obtain intraoperative imaging of the guide wire prior to reaming the socket. The purpose of this study was to investigate the effect of the use of 3D intraoperative fluoroscopy on socket placement in patients undergoing all-epiphyseal ACLR. It was hypothesized that 3D imaging would allow for more accurate intraoperative visualization of the growth plate and hence a lower incidence of growth plate violation compared to 2D imaging.

METHODS

Patients under the age of 18 who underwent a primary all-epiphyseal ACL reconstruction by the senior authors and had an available postoperative MRI were retrospectively reviewed. Demographic data, surgical details, and the distances between the femoral socket and distal femoral physis (DFP) and tibial socket and proximal tibial physis (PTP) were recorded. Patients were split into two groups based on type of intraoperative fluoroscopy used: a 2D group and a 3D group. Interrater reliability of radiographic measurements was evaluated using intraclass correlation coefficient (ICC).

RESULTS

Seventy-two patients fit the inclusion criteria and were retrospectively reviewed. 54 patients had 2D imaging and 18 patients had 3D imaging. The mean age at time of surgery was 12.3 ± 1.5 years, 79% of patients were male, and 54% tore their left ACL. The mean time from surgery to postoperative MRI was 2.0 ± 1.1 years. The ICC was 0.92 (95% CI 0.35-0.98), indicating almost perfect interrater reliability. The mean difference in distance between the tibial socket and the PTP was significantly less in the 2D imaging group than the 3D imaging group (1.2 ± 1.7 mm vs 2.5 ± 2.2 mm, p = 0.03). The femoral and tibial sockets touched or extended beyond the DFP or PTP, respectively, significantly less in the 3D group than in the 2D group (11% vs 43%, p < 0.000, 17% vs 65%, p < 0.000).

CONCLUSION

There was a significantly increased distance from the PTP and decreased incidence of DFP violation with use of 3D intraoperative imaging for all-epiphyseal ACLR socket placement. Surgeons should consider utilizing 3D imaging prior to creating femoral and tibial sockets to potentially decrease the risk of physis violation in these patients.

LEVEL OF EVIDENCE

III.

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).

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.

Overgrowth After Pediatric Tibial Spine Repair with Symptomatic Leg Length Discrepancy: A Case Report

CASE

A 12-year-old girl sustained a right-sided tibial spine fracture while jumping on a trampoline. Postoperative course was complicated initially by arthrofibrosis requiring manipulation under anesthesia and subsequent leg length discrepancy attributed to posttraumatic overgrowth necessitating femoral epiphysiodesis. Ten years after initial injury, she reported her knee to be 63% of normal and an International Knee Documentation Committee score of 63.2. Symptomatic overgrowth requiring epiphysiodesis after tibial spine repair has not been previously reported to our knowledge.

CONCLUSION

Tibial spine fixation, although previously associated with growth arrest because of physeal damage, may also result in symptomatic limb overgrowth.

Secondary Injuries After Pediatric Anterior Cruciate Ligament Reconstruction: A Systematic Review With Quantitative Analysis

BACKGROUND

In the skeletally mature anterior cruciate ligament (ACL) reconstruction population, patients aged <25 years are at significantly increased risk of graft failure and injury to the contralateral ACL. Skeletal immaturity often affects graft selection and reconstruction technique.

PURPOSE

To examine the incidence of ipsilateral graft failure and contralateral ACL injury in the skeletally immature patient population.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Using the PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines, we reviewed all literature that involved ACL reconstruction performed on skeletally immature patients between May 1976 and May 2019. Patient demographics, surgical technique, and the prevalence of ipsilateral graft failure or subsequent contralateral ACL injury were recorded. Ipsilateral, contralateral, and secondary ACL injuries were then compared between sexes via chi-square tests.

RESULTS

A total of 24 articles (1254 children; 1258 knees) met inclusion criteria for analysis. Ipsilateral graft failures occurred in 105 of 1258 patients (8.3%), and there were no statistically significant sex differences in the prevalence of graft failures (female, 9.7%; male patients, 7.1%; P = .14). The prevalence of contralateral ACL injury was significantly greater in female (29/129; 22.5%) than male (18/206; 8.7%; P = .0004) patients in the 9 studies that reported contralateral injury. Skeletally immature female patients were at significantly increased risk of contralateral ACL injury (odds ratio = 3.0; P = .0006) when compared with their male counterparts.

CONCLUSION

In the literature to date, 1 in 3 female skeletally immature patients experienced an ipsilateral graft failure or contralateral ACL injury. Regardless of sex, the 24% prevalence of secondary injury after pediatric ACL reconstruction is almost identical to previously published secondary injury rates in skeletally mature patients <25 years old. As such, skeletal maturity alone does not seem to be a determinant of secondary injury; however, there is a clear need to improve postoperative rehabilitation, activity progression, and return-to-play testing to allow a safe return to sports that protects the long-term health of the reconstructed and contralateral limbs, especially for female patients.

Use Caution When Assessing Preoperative Leg-Length Discrepancy in Pediatric Patients With Anterior Cruciate Ligament Injuries

BACKGROUND

Pre- and postoperative standing hip-to-ankle radiographs are critical for monitoring potential postoperative growth arrest and resultant deformities after pediatric anterior cruciate ligament (ACL) reconstruction.

PURPOSE

To determine the prevalence of apparent preoperative leg-length discrepancies (LLDs) that resolve at the first postoperative radiographic examination in patients undergoing ACL reconstruction in order to understand what proportion of the noted preoperative deformities may have been inaccurate.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review of prospectively collected preoperative and first postoperative full-length hip-to-ankle radiographs was performed in a cohort of skeletally immature patients who had an acute ACL injury and underwent subsequent surgical reconstruction. Leg length measurements for both the injured and the uninjured legs were obtained for comparison.

RESULTS

A total of 112 patients (mean age, 12.7 ± 1.7 years) were included (79 boys and 33 girls). Leg-length measurement interrater reliability among 3 raters for 25 randomly chosen images was nearly perfect (intraclass correlation coefficient, 0.996; 95% CI, 0.994-0.998). At baseline, there was no apparent preoperative LLD (<5 mm) in 48% (n = 54) of participants, while 37% (n = 41) displayed a small apparent LLD (5 to <10 mm), 12% (n = 13) displayed a moderate apparent LLD (10 to <15 mm), and 4% (n = 4) displayed a large apparent LLD (≥15 mm). Of the patients with an apparent preoperative LLD, 66% (n = 38) of them tore their ACL on the leg measuring shorter. At first postoperative radiographs, 48% (n = 28) of patients with an apparent preoperative LLD showed resolution to no LLD: 46% (n = 19) of patients with a small apparent preoperative LLD, 54% (n = 7) of patients with a moderate apparent LLD, and 50% (n = 2) of patients with a large apparent LLD.

CONCLUSION

A high percentage of patients (48%) with apparent preoperative LLDs showed resolution to no LLDs by their first postoperative imaging, indicating that preoperative hip-to-ankle radiographs display some false LLDs in patients with recent ACL tears who are unable to fully extend their injured leg and bear weight.

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.

ACL Injuries Aren't Just for Girls: The Role of Age in Predicting Pediatric ACL Injury

BACKGROUND

Female athletes have a higher rate of anterior cruciate ligament (ACL) injuries than male athletes; however, the role of age in mediating this injury risk has not been explored. The purpose of this study was to characterize the relationship between age and sex in predicting ACL injury in the pediatric population.

HYPOTHESIS

Prepubescent boys are more likely to sustain an ACL injury than prepubescent girls.

STUDY DESIGN

Descriptive epidemiological study.

LEVEL OF EVIDENCE

Level 4.

METHODS

Data were collected from the Statewide Planning and Research Cooperative System database for the state of New York from 1996 to 2016. The database was queried for patients aged ≤19 years who had been diagnosed with an ACL tear using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code 844.2 or the ICD-10 (10th Revision) codes S83.512A/S83.511A/S83.519A. Patient age and sex at time of ACL injury diagnosis were recorded. Chi-square analysis was used to compare the frequency of ACL injury between groups, with statistical significance set atP < 0.05.

RESULTS

A total of 20,128 patients aged ≤19 years were diagnosed with an ACL tear (10,830 males, 9298 females; male:female, 1.16:1). In all, 129 patients aged <12 years sustained an ACL tear (85 boys, 44 girls; male:female, 1.93:1), and 19,999 of those patients were aged 12 to 19 years (10,745 males, 9254 females; male:female, 1.16:1). Chi-square analysis demonstrated a significant relationship between sex and age group (P < 0.006). Additional analysis revealed that female athletes were most at risk for ACL injury from ages 12 to 16 years, with 4025 male and 5095 female athletes sustaining ACL injuries in this group (male:female, 1:1.27; P < 0.0001).

CONCLUSION

Prepubescent boys (aged <12 years) are more likely to sustain an ACL injury than same-aged female peers.

CLINICAL RELEVANCE

This study demonstrates that the risk of ACL injury varies with age and sex throughout childhood and adolescence, further guiding treatment and prevention for these pediatric athletes.

All-epiphyseal anterior cruciate ligament reconstruction produces good functional outcomes and low complication rates in pediatric patients: a systematic review

PURPOSE

To assess the literature on indications, outcomes, and complications in pediatric patients undergoing all-epiphyseal (AE) anterior cruciate ligament reconstruction (ACLR).

METHODS

PubMed, Medline, and Embase were searched for literature evaluating AE ACLR in pediatric patients. All included studies were assessed for quality using the Methodological Index for Non-Randomized Studies (MINORS). Descriptive statistics are presented where applicable.

RESULTS

Overall, 17 studies comprising 545 patients, with a mean age of 12.0 ± 1.2 (range 8-19) met the inclusion criteria. The graft choices in this systematic review included hamstring tendon autografts (75.4%, n = 403), quadriceps tendon autograft (6.2%, n = 33), Achilles tendon allograft (3.6%, n = 19) and posterior tibialis tendon allograft in one patient (0.2%, n = 1). Time of return-to-sport ranged from 8 to 22 months. Postoperative subjective IKDC scores were above 90 points. The rate of return-to-sport after AE ACLR was 93.2% (n = 219/235) and 77.9% (n = 142/183) of patients returned to sport at pre-injury level. The overall complication rate was 9.8% (n = 53/545) with the most common complication being ACL re-rupture (5.0%; n = 27/545). Only 1.5% (n = 8/545) of patients demonstrated growth disturbances.

CONCLUSION

Overall, the AE ACLR technique can achieve good postoperative functional outcomes while notably minimizing the incidence of primary issue of physeal disruption and potential associated leg-length discrepancies. AE ACLR should be considered in pediatric patients with at least 2 years of skeletal growth remaining based on radiographic bone age to minimize the impact of growth-related complications.

LEVEL OF EVIDENCE

IV (Systematic Review of Level III and IV evidence).

Validated Pediatric Functional Outcomes of All-epiphyseal ACL Reconstructions: Does Reinjury Affect Outcomes?

BACKGROUND

Greater frequency and intensity level of sports participation may be contributing to an increasing incidence of anterior cruciate ligament (ACL) tears in skeletally immature athletes. Prior studies have assessed the functional outcomes of physeal-respecting ACL reconstruction in this patient population based on adult functional outcomes scoring systems; however, there is only sparse literature evaluating functional outcomes of this specific patient population. This study aimed to retrospectively evaluate a cohort of pediatric patients who had undergone all-epiphyseal ACL reconstruction (AEACLR) with a set of clinically validated, pediatric-specific patient-reported functional outcomes scores (PRFOS). We hypothesized that patients who had rerupture would have significantly lower outcomes scores compared with those who did not rerupture.

METHODS

This was a retrospective evaluation of AEACLR patients at a single, tertiary care, children's hospital within a period of 2 years and had >6 months of initial clinical postoperative follow-up. Those who consented to participation were provided an online combined survey including questions relating to demographics and rerupture as well as 3 validated pediatric PRFOS. Statistical analysis of the cohort demographics, PRFOS, and subgroup analysis of the rerupture group compared with the ACL intact patients was performed.

RESULTS

The mean functional outcome scores at a mean of 48.6 months from surgery demonstrated excellent return to functional activity (Mean International Knee Documentation Committee, 93.8; Pedi-Patient-Reported Outcomes Measurement Information System, 98.8; Pedi- Functional Activity Brief Score, 21.6). There was a 13% rerupture rate and rerupture patients had a significantly decreased Pedi-International Knee Documentation Committee (94.9 intact vs. 86.0 rerupture; P=0.001) and Pedi-Patient-Reported Outcomes Measurement Information System (99.4 intact vs. 95.4 rupture; P=0.001) scores.

CONCLUSIONS

AEACLR patients have excellent outcomes based on pediatric-specific PRFOS. Rerupture patients demonstrated a decrease in functional outcomes scores compared with intact ACL patients. The results demonstrate the efficacy of AEACLR as measured by pediatric-specific functional outcome scores for the treatment of ACL rupture in skeletally immature athletes.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Pediatric Anterior Cruciate Ligament Reconstruction

The increasing incidence of anterior cruciate ligament injuries in skeletally immature children demands careful attention by orthopedic surgeons. Assessing skeletal age is essential to selecting the appropriate reconstruction technique. Males with a bone age of 15 years or older and females of 13 years and older are ideal candidates for a transphyseal anterior cruciate ligament reconstruction because there is minimal risk of growth disturbance. Children with substantial growth remaining (skeletal age males ≤12 years and females ≤10 years) seem to be at risk for more significant growth disturbance, so we generally recommend physeal-sparing techniques for these younger patients.

Complications After Pediatric ACL Reconstruction: A Meta-analysis

BACKGROUND

The purpose of this meta-analysis is to review clinical outcomes and complications following pediatric anterior cruciate ligament (ACL) reconstruction.

METHODS

The PubMed and EMBASE databases were searched for studies on ACL ruptures in the skeletally immature from 1985 to 2016. Full-text studies in English and performed on humans were included (n=5718). Titles included discussed operative intervention on skeletally immature patients with ACL tears (n=160). Studies that reported rerupture and/or complications with ACL reconstruction specific to the pediatric population, specifically growth disturbance, were then included in a secondary analysis (n=45). Complications not specific to the pediatric population were excluded. Demographics, graft type, surgical technique, follow-up, growth disturbance, rerupture, and patient-reported outcome scores were collected. Data were analyzed in aggregate.

RESULTS

In total, 45 studies were included with 1321 patients and 1392 knees. The average age was 13.0 years, 67% were male, and mean follow-up was 49.6 months. There were 115 (8.7%) reruptures in the initial 160 studies reviewed. In total, 94.6% of patients with rerupture required revision ACL surgery. There were 58 total growth disturbances (16 required corrective surgery, or 27.6%). Eighteen knees (3.7%) developed angular deformity, most commonly valgus. There were 37 patients (7.5%) had at least a 1 cm limb-length discrepancy. A total of 23 studies reported International Knee Documentation Committee scores (range, 81 to 100, 88% grade A or B). In total, 20 studies reported excellent Lysholm scores with mean scores of 94.6.

CONCLUSIONS

Growth disturbance can occur with any of the reconstruction techniques. Proper surgical technique is likely more important than the specific reconstruction technique utilized. Patients with rerupture require surgery at much higher rates than those with growth disturbance. Although much attention has been focused on growth disturbance, we suggest that equal attention be given to the prevention of rerupture in this age group.

LEVEL OF EVIDENCE

Level III.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

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

RESULTS

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

CONCLUSION

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

Knee Pathology in Young Adults After Pediatric Anterior Cruciate Ligament Injury: A Prospective Case Series of 47 Patients With a Mean 9.5-Year Follow-up

BACKGROUND

The rate of secondary knee injuries after pediatric anterior cruciate ligament (ACL) injury is uncertain, and previous studies are limited because of poor methodology.

PURPOSE

To evaluate the incidence of new meniscal injuries since the initial diagnostic magnetic resonance imaging (MRI) of young adults who sustained a pediatric ACL injury. In addition, to evaluate meniscal and cartilage injuries in the index knee and contralateral knee injuries on MRI at final follow-up (9.5 years). Furthermore, to assess leg length and alignment based on long-leg radiographs.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Study population at final follow-up included 47 young adults who sustained a pediatric ACL injury before age 13 years. They were followed prospectively since the time of injury for a mean 9.5 years at final follow-up. Imaging included diagnostic MRI of the index knee and 3.0-T MRI of both knees at 1-, 2-, and 9.5-year follow-up, in addition to long-leg radiographs at final follow-up. Forty-three patients underwent active rehabilitation without ACL reconstruction initially; 4 were treated with initial ACL reconstruction. At final follow-up, 27 (57%) had undergone ACL reconstruction.

RESULTS

Fourteen patients had meniscal tears in the index knee at final follow-up (prevalence, 30%). The majority of these were in the same location as previously repaired tears (n = 9). Between diagnostic MRI and final follow-up, 16 patients had sustained new meniscal tears to a healthy meniscus (incidence, 34%). At final follow-up, meniscal injuries recorded at baseline or during follow-up were no longer visible and appeared healed in 17 patients (20 tears). MRI at final follow-up showed cartilage injuries in the index knee of 13 patients (28%) and contralateral injuries in 8 patients (meniscus, n = 2; cartilage, n = 5; subchondral fracture, n = 1). Two patients had a leg-length difference >15 mm, and 3 had side-to-side difference in knee alignment >5°.

CONCLUSION

The incidence of new meniscal tears after pediatric ACL injury was 34% during a mean follow-up period of 9.5 years. At final follow-up, 27 patients (57%) had normal menisci, and none had developed knee osteoarthritis. Primary active rehabilitation, close follow-up, and delayed surgery if needed may be a viable and safe treatment option for some pediatric ACL injuries.

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.

Return to Sport and Reoperation Rates in Patients Under the Age of 20 After Primary Anterior Cruciate Ligament Reconstruction: Risk Profile Comparing 3 Patient Groups Predicated Upon Skeletal Age

BACKGROUND

With sports specialization and level of competition on the rise, anterior cruciate ligament reconstruction (ACLR) in athletes under the age of 20 has increased significantly in recent years. Reports have demonstrated that the revision ACLR rate is higher and return to sport (RTS) rate is lower in this population.

PURPOSE

To evaluate the 2-year clinical outcomes of 3 cohorts of primary ACLR in pediatric and adolescent athletes under the age of 20 based on skeletal age with a focus on RTS and the incidence of second surgery.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This is a prospective evaluation of 324 athletes younger than 20 years of age who underwent ACLR with minimum 2-year follow-up. The surgical technique was selected predicated on skeletal age, which includes the all-epiphyseal technique with hamstring autograft in the youngest cohort in elementary and middle school (group 1), the partial transphyseal and complete transphyseal with hamstring autograft performed for athletes in the middle cohort (group 2), and bone-tendon-bone autograft in the skeletally mature high school athletes (group 3).

RESULTS

The mean chronological age of the entire cohort was 15 years (range, 8-19 years) with 55% males. The 3 cohorts included 49 patients (15%) in group 1 (mean age, 12 years), 66 (20%) in group 2 (mean age, 14.3 years), and 209 (65%) in group 3 (mean age, 16.2 years). Group 2 athletes had a significantly higher revision ACLR rate (20%) compared with group 1 (6%; P = .039) and group 3 (6%; P = .001). Similarly, group 2 athletes had significantly lower RTS rates (85%) compared with group 1 (100%) and group 3 (94%).

CONCLUSION

The rate of revision ACLR was significantly higher and the RTS rates significantly lower in group 2 compared with groups 1 and 3. This age-related risk profile may be used to counsel athletes and parents preoperatively regarding the expectations of surgery with respect to revision ACLR and RTS rates.

Editorial Commentary: Mild Limb Asymmetry and Pediatric Anterior Cruciate Ligament Reconstruction-A Classic "Chicken and Egg" Scenario?

Growth disturbance from a physeal injury is considered by many surgeons to be the most feared iatrogenic surgical complication after anterior cruciate ligament (ACL) reconstruction in skeletally immature patients, typically resulting in valgus, recurvatum, and/or a short limb. These deformities also predispose children to an ACL injury in the first instance, and therefore, a firm understanding of the contributions of both preoperative deformity and iatrogenic injury to postoperative limb asymmetry is critical. Preoperative and postoperative imaging (until 2 years postoperatively or skeletal maturity) should include standing hip-to-ankle alignment radiographs when the patient is able to straighten the knee and fully bear weight, as well as a lateral projection of the knee to quantify tibial slope. This should be the standard of care for children with open physes undergoing ACL reconstruction.

MRI assessment of growth disturbances after ACL reconstruction in children with open growth plates-Prospective multicenter study of 100 patients

INTRODUCTION

We were interested in the consequences of anterior cruciate ligament (ACL) reconstruction on the growth plates and the impact on growth in children with open growth plates. The primary objective was related to growth disturbances with the null hypothesis being that ACL reconstruction in open growth plates does not cause any. The secondary objective related to the presence of physis lesions on MRI, with the null hypothesis being that ACL reconstruction in open growth plates does not induce any.

MATERIAL AND METHODS

In the context of a 2017 SFA symposium on ACL reconstruction with open growth plates, we conducted a prospective multicenter study with 2 years' follow-up. The study enrolled 100 patients; 71 were available for analysis. Four reconstruction techniques were used: semitendinosus-gracilis (STG), short graft (SG), quadriceps tendon (QT) and fascia lata (FL). MRI was used to look for growth disturbances as evidenced by deviation of the Harris lines or modification of the physis and diaphysis angles. Physis lesions were determined on MRI based on the presence of physeal bone bridges (PBB).

RESULTS

No growth disturbances were found. However, PBBs were found in 14 patients (20%). At the femur, the relative risk (RR) was higher when a STG graft was used (RR=2.1) and the tunnel diameter was≥9mm (RR=1.7). Epiphyseal fixation had a higher risk than transphyseal fixation (RR=1.6 vs. 1.2). At the tibia, the RR was higher when a QT graft was used (RR=3.6), when screw fixation was performed (RR=3.7) or when the graft did not fill the tunnel sufficiently (RR=1.5).

DISCUSSION

The absence of growth disturbances after 2 years' follow-up validates the possibility of ACL reconstruction with open growth plates, including with transphyseal techniques. The presence of small growth plate lesions such as bone bridges means that precautions should be taken with respect to tunnel trajectory, tunnel diameter, graft and tunnel diameter matching and graft fixation.

LEVEL OF EVIDENCE

III, prospective cohort study.

Outcomes of Physeal-Sparing ACL Reconstruction with Iliotibial Band Autograft in Skeletally Immature Prepubescent Children

BACKGROUND

Anterior cruciate ligament (ACL) tears are occurring in youth athletes with increasing frequency. Many ACL reconstruction procedures designed to allow for continued growth in patients with open physes have been described, but large series with mid- to long-term outcomes data are lacking. The purpose of the current study was to assess the clinical outcomes of a large cohort of prepubescent children who underwent a physeal-sparing, combined intra- and extra-articular ACL reconstruction with iliotibial (IT) band autograft over a 23-year period.

METHODS

Included in our analysis were 237 patients (240 knees) who underwent ACL reconstruction using IT band autograft at Tanner stage 1 or 2 (mean age of 11.2 ± 1.7 years). Physical examination data were analyzed for 225 of the 240 knees (mean follow-up, 25.8 months), and 137 (57%) of the knees had corresponding patient-reported clinical outcomes (patient-reported graft rupture and Pediatric International Knee Documentation Committee [Pedi-IKDC], Tegner activity scale, and Lysholm scores; mean follow-up, 6.2 years). Rates of growth arrest, IT band graft-harvest morbidity, and return to sports were analyzed.

RESULTS

Physical examination revealed that 96.8% of the knees were grade A on the Lachman test and 98.8% were grade A on the pivot-shift test. Graft rupture occurred in 9 (6.6%) of 137 knees, at an average of 33.5 months (range, 8.2 months to 8.0 years) postoperatively. For patients who did not sustain a graft rupture, the mean Pedi-IKDC score was 93.3 ± 11.0, the mean Lysholm score was 93.4 ± 9.9, and the mean score on the Tegner activity scale was 7.8 (mode, 7). While lateral thigh asymmetry at the IT band harvest site was noted by 48% of the subjects, only 1.6% reported associated pain. No cases of limb-length discrepancy or angular deformity were observed.

CONCLUSIONS

This procedure was associated with excellent functional outcomes, minimal risk of growth disturbance, and a low graft-rupture rate in skeletally immature prepubescent children. These results appear durable at mid- to long-term follow-up, at an average of >6 years postoperatively.

LEVEL OF EVIDENCE

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

Editorial Commentary: The All-Epiphyseal Anterior Cruciate Ligament Distal Femoral Approach: Sockets or Tunnels?

I believe that the distal femoral approach for anterior cruciate ligament reconstruction in the skeletally immature athlete with 3 to 6 years of remaining growth is best performed with an all-inside, all-epiphyseal technique using sockets rather than an outside-in approach creating tunnels. A shorter socket rather than a longer tunnel exposes a smaller surface area of the lateral distal femoral physis to potential compromise and resultant valgus malalignment. In addition, exiting the lateral femoral aspect of the epiphysis with a full-diameter tunnel as compared with a smaller diameter drill hole used to prepare a socket places the posterior articular cartilage, the lateral collateral ligament and anterolateral ligament footprints, and the popliteus tendon insertion at risk. My preference for sockets is also related to my belief that they provide a superior biologic milieu for graft incorporation compared with a full-length tunnel with the attendant violation of the lateral femoral cortex of the epiphysis.

Current Strategies and Future Directions to Optimize ACL Reconstruction in Adolescent Patients

The incidence of anterior cruciate ligament (ACL) injuries in the pediatric population has risen in recent years. These injuries have historically presented a management dilemma in skeletally immature patients with open physes and significant growth remaining at time of injury. While those nearing skeletal maturity may be treated with traditional, transphyseal adult techniques, these same procedures risk iatrogenic damage to the growth plates and resultant growth disturbances in younger patients with open physes. Moreover, conservative management is non-optimal as significant instabilities of the knee remain. Despite the development of physeal-sparing reconstructive techniques for younger patients, there remains debate over which procedure may be most suitable on a patient to patient basis. Meanwhile, the drivers behind clinical and functional outcomes following ACL reconstruction remain poorly understood. Therefore, current strategies are not yet capable of optimizing surgical ACL reconstruction on an individualized basis with absolute confidence. Instead, aims to improve surgical treatment of ACL tears in skeletally immature patients will rely on additional approaches in the near future. Namely, finite element models have emerged as a tool to model complex knee joint biomechanics. The inclusion of several individualized variables such as bone age, three dimensional geometries around the knee joint, tunnel positioning, and graft tension collectively present a possible means of better understanding and even predicting how to enhance surgical decision-making. Such a tool would serve surgeons in optimizing ACL reconstruction in the skeletally immature individuals, in order to improve clinical outcomes as well as reduce the rate of post-operative complications.