What's New in Pediatric Sports Conditions of the Knee?

Osteochondritis dissecans of the knee: Epidemiology, etiology, and natural history

Osteochondritis dissecans of the knee is a disease that typically affects skeletally immature patients. Clinically manifested with knee pain, limping, and joint disfunction, this condition has remained misunderstood and undervalued for a long period. Although being a rare condition, its awareness is of utmost clinical interest because of the possible severe consequences it can bring when misrecognized or inadequately treated. Its etiology remains unclear and is still debated. Many theories have been proposed, including inflammation, local ischemia, subchondral ossification abnormalities, genetic factors, and repetitive mechanical microtrauma, with a likely interplay of the same. This review article aims to deliver and discuss current and up-to-date concepts on epidemiology, etiology, and natural history of this pediatric condition. Level of evidence: level V.

Isolated ACL Reconstruction Versus ACL Reconstruction Combined With Lateral Extra-articular Tenodesis: A Comparative Study of Clinical Outcomes in Adolescent Patients

BACKGROUND

Young patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) are at a particularly high risk of graft ruptures compared with adults. Recent studies have demonstrated significant reductions in ACL graft rupture rates in high-risk adult populations when a lateral extra-articular procedure is performed, but comparative studies in pediatric and adolescent populations are currently lacking in the literature.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare the clinical outcomes of isolated ACLR versus combined ACLR and lateral extra-articular tenodesis (LET) when using the Arnold-Coker modification of the MacIntosh procedure in early adolescent patients. The hypothesis was that combined procedures would be associated with a significantly reduced risk of graft ruptures.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective analysis of consecutive early adolescent patients who underwent ACLR using a hamstring tendon autograft with or without the Arnold-Coker modification of the MacIntosh procedure was conducted. Patients with ≥1 additional risk factors for a graft rupture were offered LET in addition to ACLR (pivot-shift grade 2 or 3, high level of sporting activity defined as Tegner activity score ≥7, participation in pivoting sports, and Segond fractures). Clinical outcomes including graft rupture rates, patient-reported outcome measure scores (Knee injury and Osteoarthritis Outcome Score and subjective International Knee Documentation Committee), knee stability, return-to-sports rates, reoperation rates, and complications were assessed. Comparisons between variables were assessed with the chi-square or Fisher exact test for categorical variables and the Student or Wilcoxon test for quantitative variables. Multivariate analyses were undertaken to evaluate risk factors for a graft rupture.

RESULTS

A total of 111 patients with a mean follow-up of 43.8 ± 17.6 months (range, 24-89 months) were included in the study; 40 patients underwent isolated ACLR, and 71 underwent ACLR + LET. The addition of LET to ACLR was associated with a significantly lower graft rupture rate compared with isolated ACLR (0.0% vs 15.0%, respectively; odds ratio, 15.91 [95% CI, 1.81-139.44]; P = .012). It was also associated with significantly better knee stability (pivot-shift grade 3: 0.0% vs 11.4%, respectively; P = .021) (side-to-side anteroposterior laxity difference >5 mm: 0.0% vs 17.1%, respectively; P = .003) and Tegner activity scores (7 vs 6, respectively; P = .010). There were no significant differences between the groups regarding the Patient Acceptable Symptom State for the patient-reported outcome measures, nor for any of the other outcome measures evaluated, and no differences in the rate of non-graft rupture related reoperations or complications. The ACLR + LET group exceeded the minimal clinically important difference with respect to the Tegner activity scale.

CONCLUSION

In a retrospective comparative cohort study of adolescents, combined ACLR and LET was associated with a significantly lower graft rupture rate and no difference in non-graft rupture related reoperations or complications compared with isolated ACLR.

Overuse Knee Pain in the Pediatric and Adolescent Athlete

Overuse knee pain is common in young athletes. There are many potential overuse injuries which present with insidious onset of pain that can challenge sports medicine providers, including Osgood-Schlatter's disease, patellofemoral syndrome, osteochondritis dissecans, and stress fractures. The differential diagnosis of insidious onset knee pain also includes malignancies, infections, and rheumatologic issues. A thorough history and physical examination can guide the treating provider in making a diagnosis and appropriate treatment plan. Although not always necessary, imaging is often helpful in overuse knee pain, and laboratory workup may be necessary. Conservative treatment is often the first recommendation in the management of overuse knee pain in young athletes, and this may include activity modification, ice, anti-inflammatory medications, bracing, and physical therapy. This review summarizes common overuse knee injuries seen in pediatric and adolescent athletes.

Pediatric ACL Tears: Natural History

BACKGROUND

Increased participation in youth sports is associated with increased rates of anterior cruciate ligament (ACL) tears in the skeletally immature. Historically, ACL reconstruction was avoided in the skeletally immature, or delayed until skeletal maturity, to avoid physeal injury and growth disturbance. Current practices and meta-analyses support early ACL reconstruction in some groups, to allow for return to activities and to avoid delayed cartilage/meniscus injury.

PURPOSE

The purpose of this article was to report on the natural history of ACL injuries in the skeletally immature.

METHODS

A review of published literature on pediatric, skeletally immature ACL tears and conservative, nonoperative treatment was conducted via Pubmed articles published from 1970 to 2018. The search criteria included the key terms "anterior cruciate ligament," "pediatric" and/or "adolescent," and "conservative" and/or "nonoperative treatment." A PRISMA workflow was used to narrow down the articles to those relevant to our analysis and available in full text format.

RESULTS

Multiple articles on the nonoperative treatment of the ACL showed secondary meniscal and cartilage damage at the time of follow-up. Some articles showed no difference between the rates of secondary injuries between the surgical and nonsurgical treatment groups; however, the nonsurgical treatment groups were often on significant activity modification. Some articles concluded that nonoperative treatment of the ACL tear may be appropriate in low risk, lower level activity patients, and those that will comply with activity restrictions. Even with bracing and PT programs, active athletes treated without surgery appear to have a concerning rate of secondary meniscus injury after the primary ACL injury event.

CONCLUSIONS

The natural history of the ACL tear shows nonoperative treatment for the skeletally immature may be a viable treatment pathway for those who are able to comply with the physical activity restrictions. For the general population of young, active adolescents, an ACL injury treated nonoperatively often leads to secondary meniscal and/or cartilage damage, which may lead to knee degeneration and functional instability.