Management of anterior cruciate ligament injuries in skeletally immature individuals

Anterior cruciate ligament (ACL) injuries in skeletally immature individuals remain a challenge for the child, the parents, orthopaedic surgeons, and physical therapists. The main challenges are the potential risk of recurrent instability, secondary injuries following nonoperative treatment, and the risks involved with surgical treatment due to the vulnerability of the epiphyseal growth plates. We first present the physiological background for considerations that must be made when advising on treatment alternatives for skeletally immature individuals after ACL injury. The implications of continuous musculoskeletal development for treatment decisions are emphasized. No randomized controlled trials have been performed to investigate outcomes of different treatment algorithms. There is no consensus in the literature on clinical treatment decision criteria for whether a skeletally immature child should undergo transphyseal ACL reconstruction, physeal sparing ACL reconstruction, or nonoperative treatment. Additionally, well-described rehabilitation programs designed for either nonoperative treatment or postoperative rehabilitation have not been published. Based on the currently available evidence, we propose a treatment algorithm for the management of ACL injuries in skeletally immature individuals. Finally, we suggest directions for future prospective studies, which should include development of valid and reliable outcome measures and specific rehabilitation programs.     

Management of anterior cruciate ligament disruptions in skeletally immature patients.

Proper treatment of anterior cruciate ligament injuries in skeletally immature patients is a highly debated topic. More aggressive surgical approaches have been explored as a consequence of the potential long-term detrimental intra-articular effects of nonoperative treatment. Concerns of growth disturbances secondary to physeal injury have been reduced as a result of various alternative surgical techniques. Estimates of the amount of growthplate disruption necessary to induce changes in osseous development have also been attempted. Ultimately, the final decision to intervene surgically is influenced by joint instability and by the patient's symptoms and compliance with nonoperative treatment. Long-term repercussions of severe intraarticular destruction with nonoperative treatment should be compared with the potential detrimental effects of surgery. If more advanced techniques are combined with an increase in clinical awareness of these risk factors, then an earlier surgical approach may be a suitable option.     

Anterior cruciate ligament injuries in the skeletally immature patient

Injuries of the anterior cruciate ligament (ACL) in children are more frequent than once thought. Special factors must be taken into consideration when treating ACL injuries in the skeletally immature patient. Risks of surgery must be weighed against potential damage to the knee caused by repeated injury. The authors prefer the use of both tibial and femoral centrally placed drill holes, hamstring tendon autografts, fixation distant from the physis, and avoidance of dissection near the physis. This technique will minimize damage to the physis and should not hinder normal growth.     

Anterior cruciate ligament injuries in the skeletally immature patient

Injuries to the anterior cruciate ligament in children and youth pose a complex clinical challenge. The literature does not provide the clinician with a well-defined natural history or pathoanatomy, nor does it show agreement as to the outcomes of various treatment choices. Decision making is made difficult by the patients' skeletal and emotional immaturity and by associated intra-articular fracture, physeal fracture, and combination injuries. In an effort to place the problem of ACL injury in children and youth into some perspective and to present an algorithm for management, this article reviews issues in its diagnosis, classification, anatomy, mechanism of injury, and management.     

The functional outcome of total tears of the anterior cruciate ligament (ACL) in the skeletally immature patient

Tears of the anterior cruciate ligament (ACL) in the skeletally immature patient are becoming more prevalent. The aim of this study was to describe the functional outcome and to evaluate the best management of total tears of the ACL in skeletally immature patient. Twenty consecutive, skeletally immature patients with a clinically evident rupture of the anterior cruciate ligament were followed up for a mean of 5.4 years. The mean age at the time of injury was 13.9 years old. The study group consisted of 13 girls and 7 boys, who were treated either conservatively, by ACL reconstruction, by primary repair or by delayed ACL reconstruction after skeletal maturity had been reached. Clinical outcomes were measured using the International Knee Documentation Committee Scoring System (IKDC) and the Knee Injury and Osteoarthritis Outcome Scoring System (KOOS). The radiological evaluation was performed using Jaeger and Wirth's criteria, and instrumented laxity testing was carried out with a Rolimeter. Five of the eight patients treated conservatively showed poor function of the knee, and this resulted in instability. Concerning the patients treated by primary repair, delayed ACL reconstruction or arthroscopic debridement, we also found none of the results to be satisfactory (seven of eight patients). The patients that were treated by a reconstruction had the best results. This was confirmed by clinical examination (Lachmann grade 1), by the IKDC (grade B) and by the KOOS with the best quality of life and no giving-way attacks. The level of evidence was therapeutic level III.     

Anterior cruciate ligament reconstruction in skeletally immature patients

Anterior cruciate ligament (ACL) reconstructions in skeletally immature patients present unique difficulties, one major concern being reconstruction-induced growth disturbances. Another issue is the failure of adolescent patients to comply with the treatment programs. Initially, activity limitations and bracing can be recommended for isolated ACL tears in young skeletally immature adolescents who are at stages I, II, and III according to the modified Tanner classification, and for whom reconstruction can be delayed until completion of skeletal maturity provided that any joint instability or meniscal injury do not develop. For symptomatic patients, partial or complete transphyseal techniques or complete transphyseal reconstruction with doubled or quadrupled hamstring tendon grafts can be applied, with special care being afforded to keep clear distance between fixation materials and the physeal plates. In patients who are at pubertal stages of IV or V or with skeletal ages above 13 (F) or 14 (M) years, a transphyseal reconstruction with hamstring autografts seems to be the best solution. It should be kept in mind that functional outcomes of ACL reconstructions in skeletally immature patients are inferior to those obtained in adults even after a prudent surgical approach without associated growth disturbances.     

ACL injuries in the skeletally immature patient

Anterior cruciate ligament injuries in the pediatric and adolescent population are becoming more common with the trends of increased participation in competitive athletics in younger children. The natural history of this injury is similar to that of the adult and results in frequent reinjury, instability, and debilitation. Delayed reconstruction has proven to be a clinically effective treatment method but requires a prolonged restriction of competitive athletics. Reconstruction in the acute and subacute period has been shown by many authors to be a successful, reproducible treatment regimen. Nonetheless, the unique pitfalls of ACL reconstruction in a skeletally immature patient must not be overlooked. A thorough preoperative evaluation for leg-length discrepancy or subtle angular deformity is essential to identify the presence of an entity that might otherwise be attributed to surgical complication. For the patient nearing skeletal maturity with little growth remaining, we recommend the standard tunnel positioning and the use of soft-tissue graft. For younger patients who have significant growth remaining, alternative physeal "safe" procedures should be considered. No prospective, randomized studies compare the clinical success of graft type, graft placement, or graft fixation in this age group. Further follow-up of existing study groups and prospective research is warranted to fine-tune the result-based decision making for treatment of this injury.     

ACL injuries in the skeletally immature patient.

Anterior cruciate ligament injuries are becoming increasingly prevalent in a younger, more athletic population. These injuries require aggressive management given the poor natural history with regard to progressive meniscal damage and advanced degenerative changes. In general, strict nonoperative management has been associated with failure in the individual committed to return to an active lifestyle. As a result a general algorithm can be expressed as follows: 1. Activity limitations and bracing are initially used for the asymptomatic skeletally immature patient with a complete ACL tear. 2. If the patient remains asymptomatic, formal reconstruction can be delayed until skeletal maturity. 3. For the symptomatic patient a precise delineation of their physical development or skeletal age is important. 4. In patients who have reached Tanner IV secondary sexual development or a skeletal age of 13-14 (F/M), a traditional transphyseal reconstruction with hamstring autografts is appropriate. 5. In the skeletally immature patient who has significant skeletal development ahead of them, the judicious use of physeal sparing procedures is an option for the surgeon comfortable with these techniques. In this case the goal is temporization until formal transphyseal reconstruction can be performed after the peak of skeletal growth.     

Transepiphyseal replacement of the anterior cruciate ligament in skeletally immature patients. A preliminary report

BACKGROUND: Fear of iatrogenic growth disturbance has prevented the routine use, in children, of anatomic methods of anterior cruciate ligament replacement that have proven successful in adults. To minimize the risk of growth disturbance, extra-articular or modified physeal sparing procedures have been performed to stabilize the knee, but these procedures do not provide isometry. This study was performed to evaluate the results of a transepiphyseal replacement of the anterior cruciate ligament in skeletally immature athletes. METHODS: From 1993 to 1999, twelve patients with a mean age (and standard deviation) of 13.3 +/- 1.4 years underwent replacement of the anterior cruciate ligament with a quadruple hamstring tendon graft performed with an arthroscopic technique and intraoperative fluoroscopic imaging for precise tunnel placement. The femoral and tibial tunnels went through the epiphyses but avoided the physes. Eight of the twelve patients also had a meniscal repair. All patients returned for follow-up, at a mean of 4.1 +/- 1.9 years (range, two to 8.2 years) after surgery. RESULTS: The mean amount of growth from the time of surgery to the time of follow-up was 16.5 +/- 10.0 cm (range, 8 to 38 cm). The difference between the lengths of the lower limbs, as measured on orthoradiographs, was not clinically relevant. The mean score on the International Knee Documentation Committee (IKDC) subjective knee form was 96.5 +/- 4.4 points (range, 86 to 100 points). Ligament laxity testing with a KT-1000 arthrometer revealed a mean side-to-side difference of 1.5 +/- 1.1 mm. The rating according to the criteria of the objective 2001 IKDC knee form was normal for seven patients and nearly normal for five. CONCLUSIONS: Transepiphyseal replacement of the anterior cruciate ligament, a technically demanding procedure with a small margin of error, should be attempted only by accomplished knee surgeons. The preliminary results in this small series, however, demonstrate that this surgical technique can be performed in prepubescent patients with efficacy and relative safety.     

Knee morphometric risk factors for acute anterior cruciate ligament injury in skeletally immature patients

PurposeKnee morphometric risk factors for noncontact anterior cruciate ligament (ACL) injury have been a popular topic with skeletally mature patients. Little research has focused on the skeletally immature, with conflicting conclusions. This study performs a comprehensive analysis of identified parameters thought to predispose to ACL injury in a skeletally immature cohort.MethodsA retrospective review of pediatric patients undergoing knee magnetic resonance imaging (MRI) was performed over a 4-year period. Inclusionary criteria included mid-substance ACL disruption, skeletal immaturity, noncontact injury, without associated ligamentous disruption, and no medical condition associated with ligamentous laxity. MRI studies were analyzed by a pediatric musculoskeletal radiologist, measuring identified bony parameters, and compared with an age-matched control group without ligamentous injury. Data were analyzed using unpaired t-tests and logistic regression.ResultsOne hundred and twenty-eight patients sustained an ACL disruption, 39 met all inclusionary criteria (66 excluded for associated ligamentous disruption, 23 skeletally mature, three traumatic mechanisms, one with Marfan syndrome). When compared to an age-matched control cohort, the notch width index (NWI) was found to be significantly smaller in the ACL-injured group (p = 0.046). Subgroups analysis demonstrated significant differences in morphometric parameters between subjects with isolated ACL injuries and concomitant medial collateral ligament (MCL) strain.ConclusionsThe NWI was significantly smaller in the ACL injury group. Significant differences were noted between isolated ACL injuries and ACL injuries with an MCL strain. This study further highlights the need for incorporating associated injury patterns when investigating the influence of morphometric factors for ACL injury in the skeletally immature.

Level of evidence

Level III.     

Anterior cruciate ligament injury in the skeletally immature

Although ACL injuries in truly skeletally immature patients are relatively uncommon events, they are experienced more frequently than initially reported--especially in the adolescent population. Natural history data is limited but appears to mirror the natural history in adults with this injury if return to high-risk activity is allowed. Treatment of this injury presents unique challenges because of the substantial growth that occurs through the distal femoral and proximal tibial physes. The physiologic skeletal maturity of the patient must be determined prior to deciding treatment. Techniques of reconstruction include physeal sparing, partial transphyseal, and transphyseal methods. Reconstruction is recommended for any patient with an "ACL +" knee (a complete ACL tear and concomitant meniscal injury) or one who is non-compliant with a nonoperative treatment program and develops symptoms of persistent instability. Short-term outcomes of functional return postreconstruction appear promising, but study numbers are small and follow-up times relatively brief in truly immature patients. Long-term outcome studies are still needed.     

Transphyseal anterior cruciate ligament reconstruction in a skeletally immature knee using anterior tibialis allograft

Anterior cruciate ligament (ACL) injury in the skeletally immature individual is being recognized with increasing frequency. Nonoperative treatment of ACL injuries in skeletally immature patients have not been favorable. Surgical treatment options for complete ACL tears include primary ligament repair, extraarticular tenodesis, transphyseal reconstruction, partial transphyseal reconstruction, and physeal-sparing reconstruction. The advantage of transphyseal reconstruction is placement of the graft tissue in an isometric position, which provides better results, according to the literature. The potential disadvantage is angular or limb-length discrepancy caused by physeal violation. Controversy exists in allograft selection about whether bone or soft tissue passes into physes. The use of standard tunnels provides reliable results, but carries the risk of iatrogenic growth disturbance from physeal injury.This article presents 4 cases of transphyseal ACL reconstruction using anterior tibialis allograft in skeletally immature patients that had satisfactory functional outcomes with no growth disturbances. This is the first report of transphyseal ACL reconstruction using anterior tibialis allograft in skeletally immature patients in the English-speaking literature. All patients underwent transphyseal ACL reconstruction using anterior tibialis tendon allograft. None of the patients had angular deformities. No early physeal arrest was measured between the preoperative and postoperative radiographs. At last follow-up, the results of the Lachman test were normal for 3 patients and nearly normal for 1 patient. All patients demonstrated full range of knee motion (comparing the reconstructed knee to the contralateral knee). The results of the pivot-shift test were normal for 3 patients and nearly normal for 1 patient. No patients reported giving way.     

High-energy knee dislocation without anterior cruciate ligament disruption in a skeletally immature adolescent

Knee dislocations are rare injuries in any age group, but even more unusual in skeletally immature individuals. Such injuries often occur from high-energy mechanisms and are commonly associated with disruption of both anterior and posterior cruciate ligaments. Although there are several previous reports of knee dislocation without disruption of the posterior cruciate ligament, there is only one report citing 3 cases of knee dislocation with the anterior cruciate ligament remaining intact, each occurring in skeletally mature individuals. We present a high-energy knee dislocation in a skeletally immature girl without anterior cruciate ligament disruption. We also discuss the evaluation, management, and outcome. Treatment of this condition with arthroscopically assisted posterior cruciate ligament reconstruction using tibialis anterior allograft 2 weeks after the acute injury resulted in complete functional recovery.     

Physeal sparing reconstruction of the anterior cruciate ligament in skeletally immature prepubescent children and adolescents

BACKGROUND: The management of anterior cruciate ligament injuries in skeletally immature patients is controversial. Conventional adult reconstruction techniques risk potential iatrogenic growth disturbance due to physeal damage. The purpose of this study was to evaluate the results of a physeal sparing, combined intra-articular and extra-articular reconstruction technique in prepubescent skeletally immature children. METHODS: Between 1980 and 2002, forty-four skeletally immature prepubescent children and adolescents who were in Tanner stage 1 or 2 (with a mean chronological age of 10.3 years) underwent physeal sparing, combined intraarticular and extra-articular reconstruction of the anterior cruciate ligament with use of an autogenous iliotibial band graft. Twenty-seven patients had additional meniscal surgery. Functional outcome, graft survival, radiographic outcome, and growth disturbance were evaluated at a mean of 5.3 years after surgery. RESULTS: Two patients underwent a revision reconstruction for graft failure at 4.7 and 8.3 years postoperatively. In the remaining forty-two patients, the mean International Knee Documentation subjective knee score (and standard deviation) was 96.7 +/- 6.0 points, and the mean Lysholm knee score was 95.7 +/- 6.7 points. The results of the Lachman examination for anterior cruciate ligament integrity was normal for twenty-three patients, nearly normal for eighteen patients, and abnormal for one patient. The results of the pivot-shift examination were normal for thirty-one patients and nearly normal for eleven patients. Four of the twenty-three patients who underwent concurrent meniscal repair had a repeat arthroscopic meniscal repair or partial meniscectomy. The mean growth in total height from the time of surgery to the final follow-up evaluation was 21.5 cm. No patient had an angular deformity measured radiographically or a discrepancy in the length of the lower extremities measured clinically. CONCLUSIONS: Physeal sparing, combined intra-articular and extra-articular reconstruction of the anterior cruciate ligament with use of an autogenous iliotibial band graft in skeletally immature prepubescent children and adolescents provides excellent functional outcome with a low revision rate and a minimal risk of growth disturbance.