A conceptual framework for a sports knee injury performance profile (SKIPP) and return to activity criteria (RTAC)

ABSTRACTInjuries to the knee, including intra-articular fractures, ligamentous ruptures, and meniscal and articular cartilage lesions, are commonplace within sports. Despite advancements in surgical techniques and enhanced rehabilitation, athletes returning to cutting, pivoting, and jumping sports after a knee injury are at greater risk of sustaining a second injury. The clinical utility of objective criteria presents a decision-making challenge to ensure athletes are fully rehabilitated and safe to return to sport. A system centered on specific indicators that can be used to develop a comprehensive profile to monitor rehabilitation progression and to establish return to activity criteria is recommended to clear athletes to begin a progressive and systematic approach to activities and sports. Integration of a sports knee injury performance profile with return to activity criteria can guide clinicians in facilitating an athlete's safe return to sport, prevention of subsequent injury, and life-long knee joint health

Coper Classification Early After Anterior Cruciate Ligament Rupture Changes With Progressive Neuromuscular and Strength Training and Is Associated With 2-Year Success: The Delaware-Oslo ACL Cohort Study

Background: Some athletes demonstrate excellent dynamic stability after anterior cruciate ligament (ACL) rupture and return tosport without ACL reconstruction (ACLR) (copers). Others demonstrate persistent instability despite rehabilitation (noncopers) andrequire surgical stabilization. Testing to determine coper classification can identify potential copers early after rupture. It is unclearhow coper classification changes after a brief intervention and how early classification relates to long-term outcomes.Purpose:(1) To evaluate the consistency of early coper classification (potential coper vs noncoper) before and after progressiveneuromuscular and strength training (NMST) among athletes early after acute ACL rupture and (2) to evaluate the association ofearly coper classification with 2-year success after ACL rupture.Study Design:Cohort study; Level of evidence, 2.Methods:This was a prospective analysis from the Delaware-Oslo ACL Cohort Study, composed of athletes consecutively enrolledearly after ACL rupture. Participants (n = 271) were tested and classified as potential copers or noncopers according to established cri-teria before and after a 10-session NMST program. Success 2 years after ACLR or nonoperative rehabilitation was defined as meeting orexceeding sex- and age-matched norms for knee function, no ACL graft rupture, and 1 episode of giving way within the previous year.The McNemar test evaluated changes in coper classification pre- to posttraining. Logistic regression adjusted for baseline characteristicswas used to evaluate the association of early coper classification and surgical status with 2-year success.Results:Of 300 athletes enrolled, 271 (90%) completed the posttraining data collection, and 219 (73%) returned for the 2-year fol-low-up. The coper classifications were different between time points: nearly half of those classified initially as noncopers becamepotential copers (P\.001). At the 2-year follow-up, 66% of the ACLR group and 74% of the nonoperative group were successful.Athletes who were potential copers posttraining and chose ACLR or nonoperative rehabilitation had 2.7 (95% CI, 1.3-5.6) and 2.9(95% CI, 1.2-7.2) times the odds of success, respectively, as compared with noncopers who chose ACLR.Conclusion:Coper classification improved after NMST; more athletes became potential copers. Athletes who were potential co-pers after NMST were more likely to succeed 2 years later regardless of whether they had surgery, strongly supporting the addi-tion of NMST before ACLR. Persistent noncopers fared poorly, indicating that more intensive rehabilitation may be needed

Effects of and Response to Mechanical Loading on the Knee

Mechanical loading to the knee joint results in a differential response based on the local capacity of the tissues (ligament, tendon, meniscus, cartilage, and bone) and how those tissues subsequently adapt to that load at the molecular and cellular level. Participation in cutting, pivoting, and jumping sports predisposes the knee to the risk of injury. In this narrative review, we describe different mechanisms of loading that can result in excessive loads to the knee, leading to ligamentous, musculotendinous, meniscal, and chondral injuries or maladaptations. Following injury (or surgery) to structures around the knee, the primary goal of rehabilitation is to maximize the patient’s response to exercise at the current level of function, while minimizing the risk of re-injury to the healing tissue. Clinicians should have a clear understanding of the specific injured tissue(s), and rehabilitation should be driven by knowledge of tissue-healing constraints, knee complex and lower extremity biomechanics, neuromuscular physiology, task-specific activities involving weight-bearing and non-weight-bearing conditions, and training principles. We provide a practical application for prescribing loading progressions of exercises, functional activities, and mobility tasks based on their mechanical load profile to knee-specific structures during the rehabilitation process. Various loading interventions can be used by clinicians to produce physical stress to address body function, physical impairments, activity limitations, and participation restrictions. By modifying the mechanical load elements, clinicians can alter the tissue adaptations, facilitate motor learning, and resolve corresponding physical impairments. Providing different loads that create variable tensile, compressive, and shear deformation on the tissue through mechanotransduction and specificity can promote the appropriate stress adaptations to increase tissue capacity and injury tolerance. Tools for monitoring rehabilitation training loads to the knee are proposed to assess the reactivity of the knee joint to mechanical loading to monitor excessive mechanical loads and facilitate optimal rehabilitation

Coper Classification Early After Anterior Cruciate Ligament Rupture Changes With Progressive Neuromuscular and Strength Training and Is Associated With 2-Year Success: The Delaware-Oslo ACL Cohort Study

Background: Some athletes demonstrate excellent dynamic stability after anterior cruciate ligament (ACL) rupture and return tosport without ACL reconstruction (ACLR) (copers). Others demonstrate persistent instability despite rehabilitation (noncopers) andrequire surgical stabilization. Testing to determine coper classification can identify potential copers early after rupture. It is unclearhow coper classification changes after a brief intervention and how early classification relates to long-term outcomes.Purpose:(1) To evaluate the consistency of early coper classification (potential coper vs noncoper) before and after progressiveneuromuscular and strength training (NMST) among athletes early after acute ACL rupture and (2) to evaluate the association ofearly coper classification with 2-year success after ACL rupture.Study Design:Cohort study; Level of evidence, 2.Methods:This was a prospective analysis from the Delaware-Oslo ACL Cohort Study, composed of athletes consecutively enrolledearly after ACL rupture. Participants (n = 271) were tested and classified as potential copers or noncopers according to established cri-teria before and after a 10-session NMST program. Success 2 years after ACLR or nonoperative rehabilitation was defined as meeting orexceeding sex- and age-matched norms for knee function, no ACL graft rupture, and 1 episode of giving way within the previous year.The McNemar test evaluated changes in coper classification pre- to posttraining. Logistic regression adjusted for baseline characteristicswas used to evaluate the association of early coper classification and surgical status with 2-year success.Results:Of 300 athletes enrolled, 271 (90%) completed the posttraining data collection, and 219 (73%) returned for the 2-year fol-low-up. The coper classifications were different between time points: nearly half of those classified initially as noncopers becamepotential copers (P\.001). At the 2-year follow-up, 66% of the ACLR group and 74% of the nonoperative group were successful.Athletes who were potential copers posttraining and chose ACLR or nonoperative rehabilitation had 2.7 (95% CI, 1.3-5.6) and 2.9(95% CI, 1.2-7.2) times the odds of success, respectively, as compared with noncopers who chose ACLR.Conclusion:Coper classification improved after NMST; more athletes became potential copers. Athletes who were potential co-pers after NMST were more likely to succeed 2 years later regardless of whether they had surgery, strongly supporting the addi-tion of NMST before ACLR. Persistent noncopers fared poorly, indicating that more intensive rehabilitation may be needed

Sport Specialization, Part I: Does Early Sports Specialization Increase Negative Outcomes and Reduce the Opportunity for Success in Young Athletes?

Context: There is increased growth in sports participation across the globe. Sports specialization patterns, which include year-round training, participation on multiple teams of the same sport, and focused participation in a single sport at a young age, are at high levels. The need for this type of early specialized training in young athletes is currently under debate. Evidence Acquisition: Nonsystematic review. Study Design: Clinical review. Level of Evidence: Level 4. Conclusion: Sports specialization is defined as year-round training (greater than 8 months per year), choosing a single main sport, and/or quitting all other sports to focus on 1 sport. Specialized training in young athletes has risks of injury and burnout, while the degree of specialization is positively correlated with increased serious overuse injury risk. Risk factors for injury in young athletes who specialize in a single sport include year-round single-sport training, participation in more competition, decreased age-appropriate play, and involvement in individual sports that require the early development of technical skills. Adults involved in instruction of youth sports may also put young athletes at risk for injury by encouraging increased intensity in organized practices and competition rather than self-directed unstructured free play. Strength-of-Recommendation Taxonomy (SORT): C