Anterior Cruciate Ligament Reconstruction in Pediatric and Adolescent Patients Using Quadriceps Tendon Autograft

Hamstring Tendon Autograft Is Associated With Increased Knee Valgus Moment After Anterior Cruciate Ligament Reconstruction: A Biomechanical Analysis

BACKGROUND

There is limited evidence related to the effects of autograft type on functional performance after anterior cruciate ligament reconstruction (ACLR).

PURPOSE/HYPOTHESIS

This study aimed to compare biomechanical outcomes during a drop vertical jump (DVJ) between patients with a hamstring tendon (HT) autograft, quadriceps tendon (QT) autograft with bone block, QT autograft without bone block, and bone-patellar tendon-bone autograft at 6 months postoperatively in an adolescent population. The authors' hypothesized there would be differences in DVJ biomechanics between athletes depending on the type of autograft used.

STUDY DESIGN

Controlled laboratory study.

METHODS

Patients aged 8 to 18 years who underwent primary ACLR were included for analysis. Kinematic and kinetic data collected during a DVJ using a 3-dimensional computerized marker system were assessed at 6 months after ACLR and compared with the uninjured contralateral limb.

RESULTS

A total of 155 participants were included. There were no significant differences in terms of age, sex, or affected leg (P≥ .1973) between groups. The HT group was significantly associated with a larger knee valgus moment at initial contact compared with the QT group (28 × 10-2 vs -35 × 10-2 N·m/kg, respectively; P = .0254) and a significantly larger maximum hip adduction moment compared with the QT with bone block group (30 × 10-2 vs -4 × 10-2 N·m/kg, respectively; P = .0426). Both the QT with bone block (-12 × 10-2 vs -3 × 10-2 N·m/kg, respectively; P = .0265) and QT (-13 × 10-2 vs -3 × 10-2 N·m/kg, respectively; P = .0459) groups demonstrated significantly decreased mean knee extension moments compared with the HT group.

CONCLUSION

The findings of this study suggest that utilizing an HT autograft resulted in a significantly increased knee valgus moment at initial contact compared with a QT autograft without bone block at 6 months after ACLR in adolescent patients performing a DVJ. A QT autograft was found to be associated with significantly decreased extensor mechanism function compared with an HT autograft.

CLINICAL RELEVANCE

This study adds unique kinematic and kinetic information regarding various ACLR autograft options and highlights the biomechanical deficits that should be taken into consideration in rehabilitation.

Prediction of quadriceps tendon-patellar bone autograft diameter in adolescents with 2-dimensional magnetic resonance imaging and anthropometric measures

OBJECTIVES

This study evaluates the correlation between the bone end and soft tissue end of the quadriceps tendon-patellar bone autograft (QPA) size and pre-operative MRI measurements of the quadriceps tendon along sections to be included in the graft harvest in adolescents. We also assessed association between graft diameter and anthropometric measures (height, weight, and BMI), age, and sex.

METHODS

Patients (10-18 years) who underwent QPA ACL reconstruction and had a pre-operative MRI were considered for inclusion. Age, height, and weight, tibial and femoral side graft diameter, and patellar bone block dimensions were collected. Using a pre-operative 2D sagittal plane MRI, we measured the quadriceps at 10-mm increments above the patella, up to 40 mm. We assessed correlation between the bone-end graft diameter and the AP measure at 10 mm above the patella, and correlation between the soft-tissue end graft diameter and the most proximal AP measure.

RESULTS

A total of 103 patients were included. A significant correlation between the soft-tissue side graft diameter and most proximal AP measurement was observed (r_s = 0.51; p < 0.001). However, measurements significantly underestimated the soft-tissue end graft diameter (9.6 ± 0.8 vs. 7.4 ± 1.1; p < 0.001). There was no correlation between the bone-end graft diameter and AP measurement 10 mm above the patella. Anthropometric measures were not associated with graft size. Skeletal maturity was associated with smaller graft size (p = 0.08).

CONCLUSION

Soft-tissue end graft diameter is associated with the AP measure of the quadriceps at 20-40 mm above the superior pole of the patella.

The outcomes of quadriceps tendon autograft for anterior cruciate ligament reconstruction in adolescent athletes: a retrospective case series

BACKGROUND

Multiple graft options exist for anterior cruciate ligament (ACL) reconstruction in an adolescent athlete. Patellar tendon harvest can lead to anterior knee pain, while hamstring tendon harvest can affect knee flexion strength and alter mechanics. Allograft is less desirable in pediatric patients due to the higher failure rate and slight risk of disease transmission. Quadriceps tendon autograft has rarely been reported for adolescent ACL reconstruction in the USA, but is an excellent option due to its large size, low donor site morbidity, and versatility. The purpose of this study is to report the outcomes of adolescents who have undergone ACL reconstruction using quadriceps tendon autograft.

METHODS

Twenty-two ACL reconstructions using the quadriceps autograft were performed on 21 pediatric patients by the senior author between 2010 and 2017. The patient's demographics, injury characteristics, imaging, physical examination findings, operative findings, outcomes and sports were recorded.

RESULTS

The average age at the time of surgery was 15 years. Two patients had open physes; the remainder had closing physes. 64% of patients had additional meniscal tears and 76% had bony contusions. The average duration of follow-up was 2.8 years (range 2-5 years). At final follow-up, there were no angular deformities or leg length discrepancies. The average quadriceps atrophy of the operative leg was 4 mm. The average Lysholm score was 98. 86% of patients returned to sports. No patients had re-rupture of their operative ACL. No incidences of infections, numbness, or anterior knee pain were reported. Two patients had a second arthroscopy for re-injury, revealing new meniscal tears but intact ACL grafts.

CONCLUSIONS

Use of quadriceps tendon autograft for ACL reconstruction in adolescent patients allows reliable return to sport with minimal complications.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Magnetic Resonance Imaging Predictive Model Determines Hamstring Autograft Size for Anterior Cruciate Ligament Reconstruction in Patients Under 18 Years Old

Purpose

To evaluate the predictive value of magnetic resonance imaging in determining hamstring autograft size preoperatively for pediatric anterior cruciate ligament reconstruction.

Methods

We conducted an analysis of patients younger than 18 years who underwent quadrupled hamstring autograft anterior cruciate ligament reconstruction. Semitendinosus tendon (ST) and gracilis tendon (GT) cross-sectional areas were measured on preoperative knee magnetic resonance imaging scans. Height, weight, body mass index, and sex were analyzed using ordinal regression analysis. A classification and regression tree (CART) was constructed to identify predictors of the predetermined intraoperative graft size of 8 mm or greater. Sensitivity and specificity were determined based on specified predictors.

Results

This study included 102 patients (52 female and 50 male patients). The average age was 15.8 ± 1.4 years. At the time of surgery, 38 patients (37.3%) had open physes, with an average age of 13.4 ± 0.96 years. Of the 102 patients, 55 (53.9%) had 8-mm or larger grafts, 31 (30.4%) had 7.5-mm grafts, and 16 (15.7%) had 7-mm or smaller grafts. In 12 patients (31.6%) with open physes, the graft size was less than 8 mm. Male patients were more likely to have 8-mm or larger grafts (P < .001), as were patients with a greater height (170.1 ± 7.3 cm vs 161.1 ± 12.0 cm, P = .013) and those with a greater weight (79.7 ± 23.4 kg vs 57.1 ± 16.2 kg, P = .005). For all patients, predictive modeling determined that if the cross-sectional areas of the ST and GT were 31.2 mm² or greater, then 87.5% of patients would have a graft size of 8 mm or greater with an 80% sensitivity and 74% specificity. Similarly, if the cross-sectional areas of the ST and GT were 31.4 mm² or greater in patients with open physes, then 100% of patients would have a graft size of 8 mm or greater with a 46% sensitivity and 99% specificity.

Conclusions

A preoperative summation of the cross-sectional areas of the ST and GT greater than 31 mm² in patients younger than 18 years with open or closed physes can help the surgeon preoperatively predict which patients will have an intraoperative graft size of 8 mm or greater. The risk factors for a smaller graft size include female sex, a shorter height, and a lighter weight.

Level of Evidence

Level III, retrospective comparative study.

Open Full-Thickness Quadriceps Tendon Autograft Harvest With Repair for Anterior Cruciate Ligament Reconstruction

Historically, one of the most common graft choices for anterior cruciate ligament (ACL) reconstruction in the pediatric population has been the hamstring autograft. Although pediatric ACL reconstructions with a hamstring autograft have allowed a majority of children and adolescents to return to athletics, it has been reported that anywhere between 6% and 38% of these patients will go on to experience subsequent graft rupture. The quadriceps tendon autograft is an alternative to the hamstring tendon autograft that demonstrates superior preliminary outcomes, and we currently recommend it for skeletally immature patients undergoing primary and revision ACL reconstruction. This paper aims to describe our technique for an open full-thickness quadriceps tendon harvest with repair.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Predicting adequacy of free quadriceps tendon autograft, for primary and revision ACL reconstruction, from patients' physical parameters

PURPOSE

Free quadriceps tendon autograft (QTA) has gained popularity for both primary and revision ACL reconstruction. The aim of this study is to measure the dimensions of quadriceps tendon and determine its correlation with patient's height, weight and BMI. This is to provide a guide for patients and surgeons in predicting the suitability of QTA for ACL reconstructions.

METHODS

A cross-sectional study in which the length and thickness of the quadriceps tendon was measured in 51 Caucasian patients who underwent primary total knee arthroplasty. Exclusion criteria include non-Caucasians and previous tendon pathology. Patients were selected from routine elective total knee arthroplasty list. Tendon length is taken from musculotendinous junction to its insertion. Thickness was measured at midpoint and at distal insertion. Patients' height, weight and BMI were recorded. The correlation between patient physical parameters and tendon dimensions were determined.

RESULTS

Subjects' median age was 65 years (range 44-87), with 34 females and 17 males. Median length of the tendon was 9 mm (range 70-110), and median insertional thickness was 9 mm (7-10 mm). Median thickness at midpoint was 7 mm (range 4-10 mm). There was moderately positive correlation between subjects' height and tendon length (correlation coefficient 0.50), and also between weight and tendon length (correlation coefficient 0.47). There was no significant correlation between subjects' BMI and the tendon length. There was also no significant correlation between tendon thickness and subject's physical parameters.

CONCLUSION

This study has shown that most patients could provide adequate QTA for ACL reconstruction. It also points to the fact that no investigation is required to predict the adequacy of QTA. Though further studies with larger sample size are required to confirm this, clinician can rely on analysing patients' physical parameter in predicting the adequacy of QTA for ACL reconstruction.

LEVEL OF EVIDENCE

II.

Outcomes of Quadriceps Tendon With Patellar Bone Block Anterior Cruciate Ligament Reconstruction in Adolescent Patients With a Minimum 2-Year Follow-up

BACKGROUND

The incidence of anterior cruciate ligament (ACL) injury in the adolescent population is increasing. The quadriceps tendon-patellar bone autograft (QPA) has been established as a reliable graft choice for ACL reconstruction in the adult population.

PURPOSE

To investigate graft failure, ability to return to sport, patient-reported functional outcomes, joint laxity, and subsequent injury among adolescent patients >2 years after primary ACL reconstruction with the QPA.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Consecutive patients who underwent QPA ACL reconstruction performed by a single surgeon were identified from an existing database. Information available in the database included demographics, concomitant/subsequent injuries, surgical procedures, graft failure, return to sport, and Lachman examination collected by medical record review. Pediatric International Knee Documentation Committee (Pedi-IKDC) and Lysholm scores were collected by telephone or during a clinic visit >2 years postoperatively.

RESULTS

The final cohort included 81 of 104 consecutive adolescent patients aged 10 to 18 years (mean ± SD, 15.9 ± 1.7 years at the time of surgery) for whom follow-up information was collected at >2 years after surgery. The cumulative incidence of graft failure within the 36-month follow-up period was 1.2% (95% CI, 0.1%-11.4%). The rate of ipsilateral non-ACL injuries was similar (1.2%; 95% CI, 0.2%-7.6%). Contralateral ACL and non-ACL injuries requiring surgical intervention were documented in 9.8% (95% CI, 4.9%-19.5%). The median Pedi-IKDC score was 94 (interquartile range, 89-98). The median Lysholm score was 99.5 (interquartile range, 89.0-100.0). At 36 months after surgery, 87.9% (95% CI, 81.4%-94.9%) of individuals had returned to play.

CONCLUSION

The quadriceps tendon-patellar autograft is a novel graft that demonstrates excellent stability and favorable patient-reported outcomes. Based on these results, the QPA is a reliable choice for primary ACL reconstruction in adolescent patients.

Quadriceps Tendon Graft Anatomy in the Skeletally Immature Patient

Background:

The quadriceps tendon (QT) is increasingly considered for primary and revision anterior cruciate ligament reconstruction in skeletally immature patients, as it may be harvested as a purely soft tissue graft with considerable tissue volume. Because of distinct rectus tendon (RT) separation from the QT complex, the potential for RT retraction exists and could lead to QT weakness after QT graft harvest.

Purpose:

To describe the anatomy of the pediatric QT and clarify decussation of the RT and QT to avoid the risk of delayed RT retraction and QT weakness after QT graft harvest.

Study Design:

Descriptive epidemiology study.

Methods:

Nine cadaveric knee specimens (aged 4-11 years) underwent gross dissection. Coronal-plane width and depth of the QT were measured at intervals proximal to the superior pole of the patella at distances of 0.0, 0.5, 1.0, and 1.5 times the length of the patella. The distance was measured from the superior patellar pole to the point of RT separation from the remainder of the deeper/posterior QT.

Results:

The median patellar length was 28 mm (interquartile range, 26-37 mm). The coronal-plane width of the QT was larger superficially/anteriorly when closest to the patella but wider when measured deeper/posteriorly as the tendon extended proximally. The median distance between the superior pole of the patella and RT separation from the QT was 0.95 times the patellar length. The distance to widening of the deeper/posterior aspect of the QT was 1.14 times the patellar length proximal to the patella.

Conclusion:

The RT begins a distinct separation from the QT above the superior pole of the patella at a median of 0.95 times the patellar length in skeletally immature specimens. The deeper/posterior aspect of the QT begins to increase in coronal-plane width proximally after a distance of 1.14 times the patellar length above the knee, while the superficial/anterior aspect of the tendon continues to narrow. Awareness of the separation of the RT from the QT, and the coronal-plane width variation aspects of the QT proximally, is important for surgeons utilizing the QT as a graft to avoid inadvertent release of the RT from the rest of the QT complex.

ACL Repair With Suture Ligament Augmentation Is Associated With a High Failure Rate Among Adolescent Patients

BACKGROUND

The anterior cruciate ligament (ACL) repair technique avoids graft harvest and therefore the risk of donor site morbidity. However, early failure rates after ACL repair with suture ligament augmentation (SLA) remain high.

PURPOSE

To compare surgical failure, functional outcomes, return to sport, and joint laxity between adolescents who underwent ACL repair with SLA and those who underwent ACL reconstruction with quadriceps tendon-patellar bone autograft (QPA).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Adolescent patients (7-18 years old) underwent ACL repair with SLA or ACL reconstruction with QPA. The authors collected data from those who had postoperative information pertaining to repaired ligament or graft failure, range of motion, complications, and return to sport at a minimum of 6 months after surgery. Participants were contacted after surgery to complete study questionnaires.

RESULTS

The cohort included 22 consecutive patients in the SLA group and 157 in the QPA group. The median duration of follow-up was 2.7 years (interquartile range, 2.0-3.6 years) in the QPA group and 3.2 years (2.2-3.4 years) in the SLA group. After adjustment for sex, age, body mass index, and time from injury to surgery, the hazard of graft failure in the SLA group was 10.66 times (95% CI, 3.41-32.92; P < .0001) that of the QPA group. The cumulative incidence of graft failure in the first 3 years after surgery was 48.8% (95% CI, 28.9%-73.1%) in the SLA group, as opposed to 4.7% (2.1%-10.3%) in the QPA group. There was no difference in return to sport between the groups. Among individuals who did not rerupture their ACL, International Knee Documentation Committee and Lysholm scores were comparable between the groups, as well as range of motion.

CONCLUSION

The risk of failure was significantly increased in the SLA group relative to the QPA group. The high risk of failure for the SLA group in this short-term follow-up should be considered when selecting the treatment for adolescent patients with an ACL injury.

Pediatric Anterior Cruciate Ligament Reconstruction

The rate of anterior cruciate ligament (ACL) ruptures diagnosed among the pediatric and adolescent population is increasing. The rise in ACL injuries may be attributed to earlier sports specialization, year-round sports participation, increased awareness, and improved ability to diagnose the injury. Treatment options for pediatric or adolescent ACL injuries include nonoperative conservative treatment, ACL repair, or various techniques for ACL reconstruction. The best course of treatment for ACL rupture in young patients continues to be debated. Anterior cruciate ligament reconstruction with autograft is currently the gold standard and has been shown to be successful in restoring joint stability. This article reviews predisposing factors, common mechanisms, diagnostic procedures, and treatments for ACL rupture in adolescent patients, with a focus on using quadriceps patellar tendon autograft. [Orthopedics. 2018; 41(3):129-134.].