What's New in Skeletally Immature ACL?

Graft Failure in Pediatric Patients After Bone-Patellar Tendon-Bone, Hamstring Tendon, or Quadriceps Tendon Autograft ACLR: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) reinjury risk is high in young athletes, with graft failure rates as high as 23%. The optimal autograft choice to minimize reinjury risk in this population is unclear.

Purpose

To compare graft failure rates between bone-patellar tendon-bone (BPTB), hamstring tendon (HT), and quadriceps tendon (QT) autografts in patients aged ≤18 years with a minimum follow-up (FU) of 24 months.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review of the literature between database inception and March 2022 encompassed PubMed/MEDLINE, Cochrane CENTRAL, Embase, and Web of Science Core Collection databases. Studies on autograft ACL reconstruction (ACLR) using HT, QT, or BPTB autograft in patients ≤18 years old with a minimum FU of 2 years were included. Graft failure rates were pooled and estimated using random-effects models via the inverse variance method and logit transformations. Meta-analyses were used to estimate failure rates and pairwise comparisons were conducted by autograft type when appropriate.

Results

A total of 24 studies comprising 2299 patients (HT: n = 1237, 44.8% female, 59.1-month mean FU; BPTB: n = 913, 67.3% female, 79.9-month mean FU; QT: n = 149, 36.4% female, 35.3-month mean FU) were included. HT exhibited the highest failure rate at 11.8% (95% CI, 9.0%-15.4%); failure rates for BPTB and QT were 7.9% (95% CI, 6.2%-10.0%) and 2.7% (95% CI, 1.0%-7.5%), respectively. HT had a significantly higher failure rate than both BPTB (Q = 5.01; P = .025) and QT (Q = 7.70; P = .006); BPTB had a significantly higher failure rate than QT (Q = 4.01; P = .045). Male patients were less likely than their female counterparts to experience graft failure after HT ACLR (odds ratio, 0.48; 95% CI, 0.25-0.95).

Conclusion

While the HT remains a common choice for ACLR, the current aggregate data indicate that BPTB and QT demonstrated significantly lower failure rates than HT ACLR in adolescent athletes ≤18 years old. The QT demonstrated the lowest failure rate in adolescents but also the lowest proportion of patients represented due to a paucity of published QT data, indicating a need for future studies with larger sample sizes that include QT autografts, reduced risk of bias, and consistent reporting on skeletal maturity and surgical technique to better determine the ideal autograft for active athletic populations ≤18 years old.

Evaluating the Readability and Quality of Online Patient Education Materials for Pediatric ACL Tears

BACKGROUND

As the rate of anterior cruciate ligament (ACL) tears increases in children, the internet has become a major source of information and education. In the United States, the average adult reads at about an eighth grade level. The National Institutes of Health recommends that patient education materials do not exceed a sixth-grade reading level. Therefore, the most accessed resources on the internet should be created with this in mind. The purpose of this study is to assess the readability and quality of online patient resources for pediatric ACL tears.

METHODS

Google was queried using the term "Pediatric ACL Tear" on May 26, 2022. The most popular sites were identified through page one of a Google search. All content was evaluated to assure information was directed toward patients. To determine reading difficulty, the most widely accepted readability tests: Flesch Reading Ease Index, Flesch-Kincaid Grade Level, and Gunning Fog Index were calculated through plain text in Microsoft Word and URL in online readability checker Readable.io.

RESULTS

The average grade level for all resources was above the recommended reading level based on both Microsoft Word and Readable.io calculations. Each source exceeded the NIH recommendation by 2.6 grade levels on average (Mean grade level readability was 8.6 ± 1.9). Four of the 6 sites were above the average US reading level, exceeding the eighth grade by an average of 1.5 grade levels. All 6 sites analyzed had a mean DISCERN score of 61.9, meeting the 'good quality' criteria.

CONCLUSION

The most readily available online materials for Pediatric ACL tears were of 'good quality' but above both the NIH-recommended readability level and the average US adult reading level. With the increasing need for treatment of ACL tears in pediatric and adolescent patients and greater internet accessibility in these populations, it is important to consider the readability of these resources in support of increased health literacy and improved outcomes.

CLINICAL RELEVANCE

It is important for physicians treating young patients with ACL tears to be aware of all sources of information and support, including content shared online as these platforms are increasingly utilized, especially by patients and families of lower socioeconomic status.

Distance to the Neurovascular Bundle for Iliotibial Band Graft Passage During Anterior Cruciate Ligament Reconstruction: A Pediatric Cadaveric Study

Background:

The Micheli technique for anterior cruciate ligament (ACL) reconstruction (ACLR) has proven to be a reliable method with a minimal risk for growth disturbance among skeletally immature patients.

Purposes:

To evaluate the Micheli technique of iliotibial band (ITB) graft passage for ACLR using cadaveric knee models and to measure the distance between the surgical instrument tip and the neurovascular bundle in the posterior knee joint: specifically, the peroneal nerve, tibial nerve, and popliteal artery.

Study Design:

Descriptive laboratory study.

Methods:

Gross dissection was performed on 17 pediatric cadaveric knees (12 male and 5 female) aged between 4 and 12 years. To simulate ITB graft passage, we passed a curved-tip hemostat clamp through the posterior capsule, with the knee flexed from 90° to 100°. Next, clinical photographs were taken, and digital imaging software was used to measure the distance in centimeters from the clamp tip to each respective neurovascular structure.

Results:

The mean distances from the clamp tip to the tibial nerve, popliteal artery, and peroneal nerve were 0.875 cm (range, 0.468-1.737 cm), 0.968 cm (range, 0.312-1.819 cm), and 1.149 cm (range, 0.202-2.409 cm), respectively. Mean values were further calculated for age groups of ≤8, 9-10, and 11-12 years. The mean distance from the clamp tip to the peroneal nerve was 1.400 cm larger for 11- to 12-year-old specimens than for ≤8-year-old specimens (95% CI, 0.6-2.2 cm; P = .005).

Conclusion:

The neurovascular structures in the posterior knee were in close proximity to the path of graft passage, with distances <1 cm in many specimens in this study. When passing the graft through the knee for an over-the-top position, surgeons should consider these small distances between the path of graft passage and critical neurovascular structures.

Clinical Relevance:

As the incidence of ACL tears is continuously increasing within the pediatric population, there are a larger number of ACLR procedures being performed. Although neurovascular injuries during ACLR are rare, this study clarifies the close proximity of neurovascular structures during ITB graft passage using the Micheli technique of ACLR.