Prediction of angular deformity and leg-length discrepancy after anterior cruciate ligament reconstruction in skeletally immature patients

Primary Proximal ACL Repair: A Biomechanical Evaluation of Different Arthroscopic Suture Configurations

Purpose: Several suture techniques have been described in the past for direct ACL repair with poor healing capacity and a high re-rupture rate. Therefore, we investigated a refixation technique for acute primary proximal ACL repair. The purpose of this study is to compare the biomechanical properties of different suture configurations using a knotless anchor. Methods: In this study, 35 fresh-frozen porcine knees underwent proximal ACL refixation. First, in 10 porcine femora, the biomechanical properties of the knotless anchor, without the ligament attached, were tested. Then, three different suture configurations were evaluated to reattach the remaining ACL. Using a material testing machine, the structural properties were evaluated for cyclic loading followed by loading to failure. Results: The ultimate failure load of the knotless anchor was 198, 76 N ± 23, 4 N significantly higher than all of the tested ACL suture configurations. Comparing the different configurations, the modified Kessler–Bunnell suture showed significant superior ultimate failure load, with 81, 2 N ± 15, 6 N compared to the twofold and single sutures (50, 5 N ± 14 N and 37, 5 ± 3, 8 N). In cyclic loading, there was no significant difference noted for the different configurations in terms of stiffness and elongation. Conclusions: The results of this in vitro study show that when performing ACL suture using a knotless anchor, a modified Kessler–Bunnell suture provides superior biomechanical properties than a single and a twofold suture. Within this construct, no failure at the bone–anchor interface was seen. Clinical relevance: Since primary suture repair techniques of ACL tears have been abandoned because of inconsistent results, ACL reconstruction remains the gold standard of treating ACL tears. However, with the latest improvements in surgical techniques, instrumentation, hardware and imaging, primary ACL suture repair might be a treatment option for a select group of patients. By establishing an arthroscopic technique in which proximal ACL avulsion can be reattached, the original ACL can be preserved by using a knotless anchor and a threefold suture configuration. Nevertheless, this technique provides an inferior ultimate failure load compared to graft techniques, so a careful rehabilitation program must be followed if using this technique in vivo.

Anterior cruciate ligament and intercondylar notch growth plateaus prior to cessation of longitudinal growth: an MRI observational study

PURPOSE

Increasing numbers of children and adolescents are being treated for ACL tears. In order for surgeons to safely optimize treatment during ACL surgery, we must better understand ACL growth and intercondylar notch patterns in the skeletally immature knee. The aim of this study is to measure ACL and intercondylar notch volume in paediatric patients and observe how these volumes change as a function of age and gender.

METHODS

Data were extracted from the picture archiving and communication systems (PACS) computer records. Sample consisted of 137 MRI knee examinations performed between January 2006 and July 2010 in patients aged 3-13. Subjects were grouped into 1-year age intervals. Patients with imaging reports including ACL tears, previous surgeries, congenital structural anomalies, or syndromes were excluded.

RESULTS

Measures of ACL volume significantly increased with age (P < 0.001). A linear increase in ACL volume was observed until the age 10, with a mean increase in volume of 148 mm(3) per age group. ACL volume plateaued at 10 years, after which minimal increase in ACL volume was observed. Sex was not found to be a significant predictor of ACL volume in the multiple linear regression (P = 0.57). Similar to ACL volume, there was a significant increase in intercondylar notch volume with age with a mean increase of 835 mm(3) per age group (P < 0.0001). Intercondylar notch volume reached a plateau at age 10, after which a minimal increase in notch volume was observed in older groups. Female patients had notch volumes that were on average 892 + 259 mm(3) smaller than male patients who were in the same age group (P = 0.0006).

CONCLUSION

The plateau in the growth of ACL and notch volume occurs at age 10, prior to the halt in longitudinal growth of boys and girls. Female patients have significantly smaller intercondylar notch volumes than their age-matched male counterparts, while no gender difference was seen in ACL volume. These results suggest that notch volume is an intrinsically sex-specific difference, which may contribute to the higher rate of ACL tears among females. These growth patterns are clinically relevant as it allows surgeons to better understand the anatomy, pathology, and risk factors related to ACL tears and its reconstruction.

LEVEL OF EVIDENCE

Observational Study, Level IV.

Anterior cruciate ligament reconstruction in adolescents (Tanner stages 2 and 3)

PURPOSE

Management of anterior cruciate ligament injuries in skeletally immature patients (in Tanner stages 2 and 3) is controversial. Conventional reconstruction used in adults can cause iatrogenic growth disturbance due to physeal damage, and studies that report long-term results using a specific technique are scarce. The aim of this study is to evaluate in a large series the mid- and long-term results of a partial transphyseal technique and define the safe percentage of lesions of the femoral growth plate.

METHODS

Between 1989 and 2012, 42 adolescents at risk of growth disturbances (growth prediction of lower limbs >5 cm-Tanner 2, 3) underwent reconstruction of the anterior cruciate ligament using the semitendinosus and gracilis tendons. Growth characteristics of all the patients were assessed preoperatively, and the percentage of damage that would be produced in the femoral physis by the drilling of a 6-mm-diameter tunnel was determined. The technique used achieved graft fixation at both insertion sites, drilling the femoral physis and avoiding the tibial physis. We distinguished two groups: (a) long-term follow-up (mean 13 years 7 months, min 10.9, max 16.2) and (b) medium follow-up (mean 6 years 3 months, min 3.7, max 9.9). All knees were evaluated subjectively by history and objectively by KT2000 testing, and X-rays of both knees were compared for osteoarthritis using the Kellgren-Lawrence classification.

RESULTS

In group A (12 patients) one osteoarthritis grade 2, one instability, and ten good stability and function were observed. The mean KT2000 arthrometer values at 30 lb showed a difference of +2.4 mm (range 1-4 mm) between the operated and non-operated sides (p < 0.05). In group B (21 patients) no growth disturbance of the lower limbs, two failures (reinjury while participating in pivoting sports), and 19 good stability and function were observed. The mean KT2000 arthrometer values at 30 lb showed a difference of +1.9 mm (range 1-5 mm) between the operated and non-operated sides (p < 0.05). The average IKDC score of all the patients was 90 (min: 68, max: 97). None of the adolescents had consequences on growth after an eccentric damage passing tendons less than 7% on the frontal plane and of 1% on cross-sectional area of the femoral physis, and after an oblique tunnel passing 6-mm-diameter tendons of the tibial epiphyseal nucleus.

CONCLUSIONS

This study defines the possibility to perform a partial transphyseal intra-articular ACL reconstruction in patients in Tanner stages 2 and 3 that avoids tibial physis, involves the distal femoral physis, and produces good results at mid- and long-term follow-up without causing growth disturbances.

LEVEL OF EVIDENCE

IV.

Reliability of estimates of ACL attachment locations in 3-dimensional knee reconstruction based on routine clinical MRI in pediatric patients

BACKGROUND

Current techniques of anterior cruciate ligament (ACL) reconstruction focus on the placement of femoral and tibial tunnels at anatomic ACL attachments, which can be difficult to identify intraoperatively.

PURPOSE

To determine whether the 3-dimensional (3D) center of ACL attachments can be reliably detected from routine magnetic resonance imaging (MRI) in patients with intact ACLs and whether the reliability of this technique changes if the ACL is torn.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

A computer technique was developed in which users identify points along ACL attachments on routine clinical MRI of preoperative knees. These attachments are then displayed on a 3D MRI reconstruction, which can be used as a visual guide for the surgeon during arthroscopic surgery. Thirty-seven pediatric patients (age range, 10-17 years) with ACL tears and 37 controls with intact ACLs were examined. Two blinded observers identified cruciate ligament attachments on routine clinical 1.5-T MRI of knees. From the resulting 3D model, the location of the center of each ligament attachment site and its area were calculated and reliability assessed.

RESULTS

Mean interobserver variation of the centers of ACL attachments for the intact versus torn ACL was 1.7 ± 0.9 mm versus 1.8 ± 1.1 mm (femoral) and 1.4 ± 0.9 mm versus 1.7 ± 1.0 mm (tibial), respectively (P > .05). The 95% confidence interval for the center location was at most 4 mm. The identified ACL attachment areas were more variable, with interobserver reliability ranging from fair to excellent by the intraclass correlation coefficient. Overlap of ligament areas between observers for the intact versus torn ACL was 70% ± 15% versus 73% ± 12% (femoral) and 79% ± 9% versus 78% ± 10% (tibial), respectively (P > .05). In all cases, intraobserver reliability was superior to interobserver reliability.

CONCLUSION

The 3D locations of ACL tibial and femoral attachment centers were identified from routine clinical MRI with variability averaging less than 2 mm between 2 observers. The margin of error was at most 4 mm, representing the thickness of a single axial MRI slice, whether the ACL was intact or torn. Remnant tissue at attachments allows a reliable assessment even of torn ligaments. Identification of the ligament attachment areas was more user dependent than was identification of the attachment centers.

Treating anterior cruciate ligament tears in skeletally immature patients

PURPOSE

To systematically review the current evidence for conservative and surgical treatment of anterior cruciate ligament (ACL) tears in skeletally immature patients.

METHODS

A systematic search of PubMed, CINAHL, EMBASE, CCTR, and CDSR was performed for surgical and/or conservative treatment of complete ACL tears in immature individuals. Studies with less than six months of follow-up were excluded. Study quality was assessed and data were collected on clinical outcome, growth disturbance, and secondary joint damage.

RESULTS

We identified 48 studies meeting the inclusion criteria. Conservative treatment was found to result in poor clinical outcomes and a high incidence of secondary defects, including meniscal and cartilage injury. Surgical treatment had only very weak evidence for growth disturbance, yet strong evidence of good postoperative stability and function. No specific surgical treatment showed clearly superior outcomes, yet the studies using physeal-sparing techniques had no reported growth disturbances at all.

CONCLUSIONS

The current best evidence suggests that surgical stabilization should be considered the preferred treatment in immature patients with complete ACL tears. While physeal-sparing techniques are not associated with a risk of growth disturbance, transphyseal reconstruction is an alternative with a beneficial safety profile and a minimal risk of growth disturbance. Conservative treatment commonly leads to meniscal damage and cartilage destruction and should be considered a last resort.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II, III, and IV studies.

The potential for primary repair of the ACL

The objective of this work is to assess the feasibility of successfully repairing the torn anterior cruciate ligament (ACL). Two major motivators for developing a new treatment for ACL injuries are the recently reported high rates of osteoarthritis, after conventional ACL reconstruction, and the problem of how to safely treat skeletally immature patients. A key factor in developing such a technique was the identification of the main inhibitor of intrinsic ACL healing-the lack of clot formation between the 2 torn ends of the ligament. A bioactive and biocompatible scaffold, which could be placed in the wound site to enhance cellular proliferation and biosynthesis, was developed. This biomaterial has shown promising functional outcomes in several large animal models of primary repair of partial and complete ACL transection over 4 to 14 weeks, suggesting potential for a successful, future clinical application.

Arthroscopic treatment of a PCL avulsion fracture in a skeletally immature patient

Posterior cruciate ligament (PCL) avulsions from the tibial attachment site in children are rare. Six cases have been reported in the English literature since 1975. Osteochondral avulsions of the PCL can be easily missed on plain radiographs in skeletally immature patients because of the rarity of these injuries and open proximal tibial physis. To properly recognize and treat the condition, careful physical examination and adequate imaging studies are crucial. Few case reports demonstrate successful surgical treatment of the injury using screw fixation. This article presents a case of a 13-year-old girl with tibial avulsion of the PCL treated by arthroscopic reduction and pull-out suture, sparing the epiphyseal plate using a posterior transseptal portal. The proximal substance of the avulsed PCL was grasped with a suture hook introduced from posterolateral to posteromedial rather than through the small, fragmented bony portion. The suture material was passed and retrieved through the bony tunnel from posterior to anterior above the epiphyseal plate. Although it has not been proven yet in terms of biomechanical benefit, we believe this alternative treatment to PCL avulsion injuries in skeletally immature patients will provide sufficient strength to maintain ligament tension during the healing process and avoid physeal injury.

The effects of anterior cruciate ligament lesion on the articular cartilage of growing goats

Treatment of anterior cruciate ligament (ACL) injury in skeletally immature patients is controversial. The growth plate could be damaged if treated with the reconstruction techniques used to treat instability in adults. For this reason, many authors postpone surgical treatment until skeletal maturity, but the acceptable length of time that treatment can be postponed without causing irreversible damage to the articular cartilage in children with ACL injury is unknown. Until now, no studies have described the pathological findings and the evolution of the lesions of the articular cartilage during the growing period. For this reason, an experimental study on 16 6-month-old, skeletally immature goats was performed. A complete ACL lesion was achieved by removing the ligament. Two animals per group were sacrificed at intervals of 1, 3, 6, and 9 months postoperatively, and macroscopic and microscopic evaluations were performed. The presence of meniscal injury and articular cartilage lesions with progressive aspects were histologically underlined. The hystological observations showed that the complete ACL lesion causes irreversible articular cartilage alterations in growing goats 3 months after injury. These experimental data suggest that ACL reconstruction in growing patients with ACL injury and instability should be indicated without waiting until skeletal maturity.

Rupture of the anterior cruciate ligament in children: early reconstruction with open physes or delayed reconstruction to skeletal maturity?

The purpose of this study was to compare two different strategies of management for ACL rupture in skeletally immature patient. In group 1, patients were treated in a children hospital by ACL reconstruction with open physis. In group 2, patients were treated in an adult hospital by delayed reconstruction at skeletal maturity assessed radiologically. Fifty-six consecutive patients were included in this retrospective study. Mean time from injury to surgery in group 1 and 2 was, respectively, 13.5 and 30 months. Patients from group 2 exhibited a higher rate of medial meniscal tears (41%) compare to group 1 (16%) and higher rate of meniscectomy. Both groups had the same rate of lateral meniscal tears. A temporary tibial valgus deformity was reported which was subsequently spontaneously resolved. No definitive growth disturbance was noticed. At 27 months mean follow-up, a best subjective IKDC score was found in group 1. Objective IKDC and radiological results were similar in both groups. Early ACL reconstruction is therefore a recommended option.

Managing anterior cruciate ligament deficiency in the skeletally immature individual: a systematic review of the literature

OBJECTIVE

To perform a systematic review of the literature to answer whether early ACL reconstruction for a skeletally immature individuals result in improved outcome compared with nonsurgical treatment or delaying the reconstruction until skeletal maturity in the pediatric athlete.

DATA SOURCES

Articles were restricted to the English language, and 6 databases were searched (MEDLINE, CINAHL, EMBASE, ACP Journal Club, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews). The following keywords were used: anterior cruciate ligament, ACL, child, immature, pediatric, pediatric, and young.

SELECTION CRITERIA

All studies examining the ACL reconstruction in skeletally immature individuals, including citations describing complications. Excluded were articles looking at ACL repairs and ACL avulsion injuries. All types of study design, including review articles, were included. Comparative studies were reviewed in detail and analyzed qualitatively.

DATA EXTRACTION AND SYNTHESIS

A total of 615 articles were identified. Sixty-six articles met the inclusion and exclusion criteria. There were no articles with levels of evidence better than level III. The majority of the articles represented case series and reviews with expert opinion.

RESULTS

There were 7 articles that provided comparisons between surgical and nonsurgical treatment in order to answer the question.

CONCLUSIONS

The study designs are inadequate to answer the question of whether early or delayed ACL reconstruction results in the best possible outcome in skeletally immature individuals. Future prospective studies are required to answer the question adequately. A proposed algorithm was described to deal with the question.

Intraarticular stabilization after anterior cruciate ligament tear in children and adolescents: results 6 years after surgery

Tear of the anterior cruciate ligament (ACL) secondary to knee sprain injury is also quite common among children and adolescents. Whether reconstruction is indicated and which technique should be employed is still controversial. The debate focuses on the possible risk of growth plate damages due to intraarticular operative reconstruction techniques. For more details on benefit and risks of operative stabilization, our clinic's large number of surgical results was to be evaluated retrospectively. In a total of 437 knee joint arthroscopies performed between 1982 and 1992 in children and adolescents with open physes, aged 3-16 years, 63 surgical repair/reconstructions according to an algorithm were carried out. The average age at surgery was 13.8 years. Follow-up an average 6.5 years after the operation consisted of clinical and radiological examination, Lysholm, Tegner, and IKDC scores. This report focuses on intraarticular ligament reconstruction methods. Forty-four patients could be followed up, comprising of five reinsertions, ten internal fixations, 15 cases semitendinosus tendon (ST) augmentations, and 14 primary reconstructions with the middle one-third of the patellar tendon (PT). In every ST and PT case, transtibial and transfemoral tunnels were drilled. The clinical stability examination was supplemented by KT-1000 arthrometer measurements and radiography in two planes. Averaged for all surgical techniques, good and very good results were obtained in over 75% of cases. There were no major growth defects and rarely signs of osteoarthrosis. According to literature, conservative treatment of ACL tears and even primary ACL repair is not infrequently followed by re-ruptures. Therefore, reconstruction is the preferred procedure for patients aged 12 years or more. As most authors hesitate to possibly block the physes by obtaining and anchoring patellar tendon grafts, the ST should be preferred. This study demonstrates in a large number of ACL stabilizations, despite transepiphyseal drilling and grafting, very good stabilization is achieved, but no growth defects have to be expected.

Age and gender effects on lower extremity kinematics of youth soccer players in a stop-jump task

BACKGROUND

Gender differences in lower extremity motion patterns were previously identified as a possible risk factor for non-contact anterior cruciate ligament injuries in sports.

HYPOTHESIS

Gender differences in lower extremity kinematics in the stop-jump task are functions of age for youth soccer players between 11 and 16 years of age.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Three-dimensional videographic data were collected for 30 male and 30 female adolescent soccer players between 11 and 16 years of age performing a stop-jump task. The age effects on hip and knee joint angular motions were compared between genders using multiple regression analyses with dummy variables.

RESULTS

Gender and age have significant interaction effects on standing height (P = .00), body mass (P = .00), knee flexion angle at initial foot contact with the ground (P = .00), maximum knee flexion angle (P = .00), knee valgus-varus angle (P = .00), knee valgus-varus motion (P = .00), and hip flexion angle at initial foot contact with the ground (P = .00).

CONCLUSION

Youth female recreational soccer players have decreased knee and hip flexion angles at initial ground contact and decreased knee and hip flexion motions during the landing of the stop-jump task compared to those of their male counterparts. These gender differences in knee and hip flexion motion patterns of youth recreational soccer players occur after 12 years of age and increase with age before 16 years.

CLINICAL RELEVANCE

The results of this study provide significant information for research on the prevention of noncontact anterior cruciate ligament injuries.

Delayed anterior cruciate ligament reconstruction in adolescents with open physes

BACKGROUND

Treatment of anterior cruciate ligament rupture in adolescents with open physes is controversial.

HYPOTHESIS

Delaying reconstruction until the physes bridge will affect the rate of additional knee injuries.

STUDY DESIGN

Case control.

METHODS

The physes group was 13 adolescents with open physes whose anterior cruciate ligament reconstructions were delayed until their physes bridged. Specific types of activity were absolutely restricted during the delay. The physes groups' rates of additional injuries, identified arthroscopically at reconstruction, were compared to rates among 116 skeletally mature adolescents. The comparison adolescents were stratified into four groups by interval from injury to reconstruction (<1 week, 1 to 6 weeks, 6 to 26 weeks, >26 weeks).

RESULTS

The additional injury rates in the physes and four comparison groups were 46%, 50%, 47%, 43%, and 69%, respectively. Severity of additional injury, mechanism of injury, and rate of additional surgical procedures were similar among the groups.

CONCLUSIONS

There was no evidence that intentionally delayed anterior cruciate ligament reconstruction increased the rate of additional knee injuries. Delayed reconstruction is a valid treatment option for adolescents with open physes at injury. Absolute activity restriction is key to decreasing the risk of additional knee injuries.

An anterior cruciate ligament and medial collateral ligament tear in a skeletally immature patient: a new technique to augment primary repair of the medial collateral ligament and an allograft reconstruction of the anterior cruciate ligament

The goal of this case report is to fill a dual purpose. We describe a case involving a tear of the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) in a skeletally immature athlete. At the same time, we describe a new technique with which we repaired the ACL with an allograft posterior tibialis tendon through intra-articular tunnels. A trial of conservative therapy for the MCL was performed. During surgery, its instability was assessed. No improvement was seen in stability, so a primary repair of the MCL was performed and augmented with an autograft gracilis tendon. The patient did well postoperatively, subsequently achieving equal stability and range of motion when compared with the opposite limb. He was back to competitive sports at 6 months.

Partial tears of the anterior cruciate ligament in children and adolescents

BACKGROUND

The functional outcome after partial anterior cruciate ligament tears in children and adolescents treated without reconstruction has not been established.

HYPOTHESIS

Nonreconstructive management of partial anterior cruciate ligament tears can be effective in certain pediatric patients.

STUDY DESIGN

Prospective cohort study.

METHODS

We studied 45 skeletally mature and immature patients 17 years of age or less who had an acute hemarthrosis, magnetic resonance imaging signal changes, grade A or B Lachman and pivot shift result, and an arthroscopically documented partial anterior cruciate ligament tears. All patients were treated without reconstruction, underwent a structured rehabilitation program, and were followed up for a minimum of 2 years.

RESULTS

Fourteen patients (31%) underwent subsequent reconstruction. Significant associations with subsequent reconstruction included tears that were greater than 50%, predominantly posterolateral tears, a grade B pivot shift test result, and older chronologic and skeletal age. Among patients who did not require reconstruction, those with tears that were greater than 50% or predominantly posterolateral had significantly lower Lysholm, satisfaction, and Cincinnati Knee Scale scores.

CONCLUSIONS

Nonreconstructive management is recommended for partial anterior cruciate ligament tears in children and adolescents 14 years of skeletal age or younger with normal or near-normal Lachman and pivot shift results. Reconstruction is recommended in older athletes or in those with greater than 50% or predominantly posterolateral tears.

Anterior cruciate ligament reconstruction in the young patient without violation of the epiphyseal plate

A technique of arthroscopic anterior cruciate ligament reconstruction that does not disturb the epiphyseal plate in the young patient with open physis is presented. A cryopreserved bone-Achilles tendon allograft was incorporated by an interference screw fixation to the bone plug in the tibia and an over-the-top positioning of the tendon on the femoral side. For this procedure, the minimal patient age that the thickness of the epiphysis can accept an interference screw greater than 15 mm in length is 8 years. An intra-articular reconstruction of anterior cruciate ligament with the cryopreserved Achilles allograft using our technique is safe and recommendable for young patients with open physis.

Anterior cruciate ligament reconstruction in patients who are prepubescent

Between 1980 and 1996, 17 children who were prepubescent have had a combined intraarticular and extraarticular reconstruction of the anterior cruciate ligament using the iliotibial band that does not violate the physes. The average chronological age of the patients was 11 years (range, 2-14 years) and the average skeletal age of the patients was 10 years (range, 2-13 years). Eight of the 10 patients who had attained skeletal maturity were evaluated at an average of 66.5 months postoperatively (range, 25-168 months). All knees were stable subjectively by history and objectively by KT1000 testing. The average Lysholm score at assessment was 97.4. No child with a traumatic disruption had leg length discrepancy develop.

Considerations in child and adolescent athletes

Excessive efforts to groom competitive and elite athletes from a very young age may expose children to significant external pressure to perform inappropriate training regimes, sometimes at the expense of their health and psychological well-being. It is essential for the physician to recognize the special physiologic, anatomic, and psychological issues of the child and adolescent athlete and to balance the benefits of appropriate participation in sports and exercise with the risks of physical and psychological injury.