Criteria Used to Determine Unrestricted Return to Activity After ACL Reconstruction in Pediatric and Adolescent Patients: A Systematic Review.

Background: The rates of anterior cruciate ligament (ACL) graft failure or contralateral ACL rupture range from 17% to 30% in pediatric patients after ACL reconstruction (ACLR). A contributing factor to the high reinjury rate in this population may be the limited evidence regarding appropriate criteria for allowing unrestricted return to activity (RTA) postoperatively. Purpose: To review the literature and identify the most commonly used criteria when determining unrestricted RTA after ACLR in pediatric patients. Study Design: Systematic review; Level of evidence, 4. Methods: A search was performed of the Medline/PubMed, Cochrane Central Register of Controlled Trials, Embase, CINAHL, and SPORTDiscus databases using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The authors identified studies that included pediatric patients (<19 years of age) and specified the criteria used to determine RTA after ACLR. Results: A total of 27 articles met all criteria for review, of which 13 studies only used 1 criterion when determining RTA. Objective criteria were the most common type of criteria for RTA (17 studies). Strength tests (15 studies) and hop tests (10 studies) were the most commonly used tasks when deriving RTA criteria. Only 2 studies used validated questionnaires to assess the patient's physiological readiness for RTA, and only 2 studies used an objective assessment of movement quality before RTA. Conclusion: Only 14 of the 27 reviewed studies reported using >1 criterion when determining RTA. Furthermore, few studies used patient-reported outcome measures or lower limb kinematics as RTA criteria, indicating that more research is needed to validate these metrics in the pediatric population.

Protocol for the systematic review of return-to-activity criteria in adolescent patients following an anterior cruciate ligament reconstruction.

BACKGROUND: Anterior cruciate ligament (ACL) rupture is a debilitating knee injury associated with sequela such as joint instability and progressive degeneration. Unfortunately, following surgical ACL reconstruction in adolescents, the rates of ACL graft failure range from 17 to 19%. A contributing factor to the high reinjury rate in this population may be the limited evidence regarding appropriate criteria for allowing unrestricted return-to-activities (RTA) postoperatively. Several systematic reviews have already sought to develop a consensus on what criteria should be utilized for releasing patients to unrestricted sports activities; however, these reviews have focused on adult populations, a group at much lower risk for reinjury. Our objective is to systematically examine the literature and identify the criteria used when determining unrestricted RTA following an ACL reconstruction in an adolescent population. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search will be performed of the MEDLINE/PubMed, Cochrane, Embase, CINAHL, and SPORTDiscus electronic databases. Searches will be conducted from January 1, 2000, until submission of the final review. Studies will be identified that include adolescent patients (10-18 years old) undergoing a primary ACL reconstruction and which have specified the criteria used to determine RTA. Each article will be independently screened by two reviewers. To supplement the electronic database search, citations within all included studies will be manually reviewed. Reviewers will record the RTA assessment utilized and the rates of ACL reinjury through a standardized data extraction sheet. Reviewers will resolve full-text screening and data extraction disagreements through discussion. Synthesis of the collected data will focus on compiling and mapping the most commonly used types of RTA criteria. DISCUSSION: This systematic review will determine the most commonly used RTA criteria in adolescent patients post-ACL reconstruction. This will help future interventions build more effective adolescent-specific RTA assessments through the validation of current RTA criteria as well as the implementation of new criteria according to the identified literature gaps.

Sex-specific landing biomechanics and energy absorption during unanticipated single-leg drop-jumps in adolescents: implications for knee injury mechanics.

Females aged between 13 and 17 years old possess the highest non-contact ACL injury incidence of any sex-age strata. Considering that energy absorption strategies have been associated with a reduced risk for sustaining an ACL injury, evaluating landing performance in youth athletes requires investigations beyond the kinematic level. The purpose of this study was to identify sex-specific energy absorption strategies in adolescent males and females, including the relationship between strength and the observed strategies. Thirty-one healthy adolescent athletes completed unanticipated single-leg drop-jump landings on their dominant limb. Sex-specific kinematics and lower-limb contributions to energy absorption were then compared over the landing phase for each jump. Pearson and Spearman correlation coefficients determined the relationship between isometric joint strength and the observed kinematics and energy absorption. Female participants absorbed a larger proportion of the landing energy at the ankle (p = 0.046, d = 0.75) and smaller proportion at the hip (p = 0.028, d = 0.85) compared to males. Females also reached larger peak negative joint power in their knee (p = 0.001, d = 1.1) and ankle (p = 0.04, d = 0.79). Hip extension strength was positively correlated with trunk flexion (r = 0.559, p = 0.001) and negatively correlated with forward pelvic tilt (r = -0.513, p = 0.003). Females adopted an energy absorption strategy which utilized the distal joints to absorb a larger portion of the landing forces and tended to absorb the forces later in the landing phase relative to males. The greater reliance on distal joints is correlated to reduced hip strength and may increase the risk for sustaining an ACL injury.

Divergence analysis of failed and successful unanticipated single-leg landings reveals the importance of the flight phase and upper body biomechanics.

The purpose of this study was to describe neuromuscular and kinematic differences during failed and successful drop-vertical jumps in a pediatric population. Healthy young athletes (n = 32) completed single-leg drop vertical jump landings where the required landing leg was unanticipated. Trials were categorized as failed if the participant shifted their base of support during the landing. Joint kinematics and muscle activation amplitudes were time normalized over the flight and landing phases. Statistical parametric mapping (SPM) was used to compare landings and a moving average convergence divergence oscillator was then calculated to determine where failed and successful waveforms began to diverge prior to reaching statistical significance. SPM determined that participants performed the failed trials with reduced pelvic tilt towards the landing limb during 41-69% of the flight phase, greater trunk flexion angle during 31-100% of the landing phase and greater trunk tilt away from the landing limb during 3-13% and 21-90% of the landing phase. Greater rectus femoris activation during the failed trials was identified during 88-100% of the flight phase, as well as 1-4% and 71-97% of the landing phase. Greater gluteus medius and biceps femoris activation was also identified in the failed trials during 54-72% and 76-89% of the landing phase respectively. These findings indicate that the control of proximal joints has an important role in determining if a participant will fail a landing; and that how athletes prepare for a landing may be more relevant than the kinematics following ground contact.

Decision Tree Learning Algorithm for Classifying Knee Injury Status Using Return-to-Activity Criteria.

Anterior cruciate ligament (ACL) injury rates in female adolescents are increasing. Irrespective of treatment options, approximately 1/3 will suffer secondary ACL injuries following their return to activity (RTA). Despite this, there are no evidence-informed RTA guidelines to aid clinicians in deciding when this should occur. The first step towards these guidelines is to identify relevant and feasible measures to assess the functional status of these patients. The purpose of this study was therefore to evaluate tests frequently used to assess functional capacity following surgery using a Reduced Error Pruning Tree (REPT). Thirty-six healthy and forty-two ACLinjured adolescent females performed a series of functional tasks. Motion analysis along with spatiotemporal measures were used to extract thirty clinically relevant variables. The REPT reduced these variables down to two limb symmetry measures (maximum anterior hop and maximum lateral hop), capable of classifying injury status between the healthy and ACL injured participants with a 69% sensitivity, 78% specificity and kappa statistic of 0.464. We, therefore, conclude that the REPT model was able to evaluate functional capacity as it relates to injury status in adolescent females. We also recommend considering these variables when developing RTA assessments and guidelines.Clinical Relevance- Our results indicate that spatiotemporal measures may differentiate ACL-injured and healthy female adolescents with moderate confidence using a REPT. The identified tests may reasonably be added to the clinical evaluation process when evaluating functional capacity and readiness to return to activity.