ACL Tear
A focus on ACL injuries is important, as these injuries may increase the risk of osteoarthritis in the future [
12]. The most common mechanism of ACL injury is a non-contact pivoting motion on a fixed foot or a trauma with the knee in hyperextension [
57]. If a hemarthrosis develops within a few hours after the trauma in the absence of a bony injury there is a 70% chance of ACL injury [
58]. The examiner should assess gait and alignment, range of motion, and assess the affected joint and compare it with the contralateral joint, taking into account that most children may have hyperlaxity which decreases with maturity [
59]. Radiographs should be examined for bony injuries. Magnetic resonance imaging (MRI) can be useful in very experienced hands [
60], but may be no better than accurate clinical examination [
60].
The management of ACL deficiency in skeletally mature children is still controversial, especially in terms of operative timing and surgical technique [
61]. Conservative management is not recommended, as it is accompanied by marked reduction in activity, decline in functional performance, and development of early osteoarthritis [
62,
63]. Historically, delayed anatomic ACL reconstructions were preferred [
64], recommending extensive rehabilitation and return to activities with a brace to skeletal maturity and growth plate closure, to allow an anatomical adult-like reconstruction [
65]. The present trend favours early reconstruction, using either extra physeal techniques in very young athletes, or anatomical reconstruction technique placing the tibial and femoral tunnels close to the centre on the growth plate of the tibia and femur in young athletes closer to skeletal maturity.
More anatomic physeal-sparing reconstruction techniques seems to be promising, but these techniques are technically challenging. Partial transphyseal techniques avoid the distal lateral femoral physis, providing more isometric tibial graft positioning and over the top reconstructions, provide excellent stability and return to sporting activities. Complete transphyseal ACL reconstruction is very similar to adult ACL reconstructions [
66]. This procedure allows ideal tunnel placement and improves graft longevity and knee function, but the incidence of growth disturbance may increase, especially in very skeletally immature children [
67‐
70].
In Tanner stage III or IV patients receiving transphyseal quadrupled hamstring autogenous ACL reconstruction, graft fixation to the femur with a suspension device and tibial fixation with interference screw have been promising [
69]. Transphyseal reconstruction is recommended for patients with Tanner II and III stages, but the evidence in Tanner stage I patients is insufficient [
70].
In general, Tanner stage IV-V children are considered adolescents without substantial growth remaining, and can be treated like adults. Tanner stage III children are considered "adolescents with substantial growth remaining" and a modified transphyseal reconstruction with soft tissue graft (hamstrings) small tunnels and avoiding fixatioin across the physis can be undertaken with little risk of physeal injury. Tanner stage I and II patients have significant growth remaining. In these children, management options are (1) brace and activity followed by delayed reconstruction when older; (2) extra-physeal reconstruction; or (3) partial/complete transphyseal, but this carries the risk of significant growth arrest. Complications of ACL reconstruction are rare, and most of the documented growth complications are secondary to surgeon errors such as placement of a fixation device across a growth plate [
71,
72]. With careful attention to surgical technique, paediatric ACL reconstruction can be safe and effective.
Concussion
Any direct blow to the head/face or a blow to the body that transmits a force to the brain can cause a concussion [
5]. Signs and symptoms of concussion can be subtle and easily overlooked. These may include headache, nausea, dizziness, difficulty concentrating or remembering, confusion and emotional lability. Younger children may present with even more subtle signs, such as abdominal pain or behavioral changes [
73]. Symptoms typically last for 7–10 days [
5], although they may be prolonged for weeks to months [
74‐
76]. In younger children, recovery may take longer [
77,
78]. Cognitive sequelae of concussion, including impaired memory, poor attention and lack of concentration, may negatively impact on a child’s ability to learn and attend to schoolwork [
74,
75,
78,
79].
Management of concussions in pediatric athletes generally adheres to adult guidelines outlined in the Zurich Consensus Statement [
5], but should be more cautious [
80,
81]. Children and adolescents take longer than adults to recover after a concussion, which underscores the need for a more conservative approach to management and return to play [
56]. Any child or adolescent suspected to have sustained a concussion should be immediately removed from play and not allowed to return until cleared by a physician [
5,
80,
81]. A concussion can be evaluated on the sideline by a coach or athletic trainer using a concussion tool such as the SCAT3 or Child SCAT 3 [
5,
80,
81]. Assessment should include a neurological exam and assessment of attention and memory.
A physician should evaluate any athlete who has sustained a concussion as soon as possible after the injury to ensure proper diagnosis. Diagnostic imaging, such as CT or MRI, is generally not required.
Studies of concussion management in paediatric patients are sparse. One study of high school and college student athletes found that cognitive and physical rest immediately after injury, as well as later during recovery, resulted in improved symptoms and increased performance on computerized neuropsychological tests [
82].
Consensus agreement is that rest, both physical and mental, is the keystone of concussion management [
5,
80]. Physical activities, including sports and exercise, and mental activities, including video games, TV, computer work, and reading, should be limited to allow symptoms to improve. Mental rest may require that a concussed athlete abstain from school or modify assignments/tests for a period of time to allow symptoms to decrease [
5,
81]. As symptoms improve, students can gradually increase cognitive tasks and social activities, including school, as long as symptoms are not exacerbated [
5,
83].
Return to learn is a vital component of concussion management in children and adolescents [
84‐
86]. Mental rest can be challenging for students. Recovery may be prolonged if students participate in cognitive tasks that exacerbate symptoms, known as "cognitive overexertion" [
84]. Students may need to abstain from school for a day or two until symptoms improve, and then gradually return (e.g., attending half-days or only certain courses), until they are able to attend full-time without exacerbating symptoms [
75,
81,
84‐
86].
Students do not need to be symptom-free to return to school. However, students may require accommodation or modifications to their schedule to allow school participation without worsening symptoms [
75,
81,
83,
84,
86]. Academic accommodations/modifications may include taking frequent breaks during the day, having a quiet area they can go to; shortened assignments, more time to complete assignments; limiting tests/exams to one per day, etc. [
75,
80,
81,
83,
84,
86]. Full return to academics must precede return to sports. If a prolonged absence from school (more than a couple of weeks) is necessary due to persistent symptoms, referral to a specialist with expertise in concussion, as well as a neuropsychologist, may be required.
Return to play decisions for pediatric athletes following a concussion can be difficult. Because of the different physiological response and longer recovery after concussion during childhood and adolescence, a more conservative return to play approach is recommended [
5,
80]. No athlete should return to sport/activity until all symptoms have resolved and medical clearance has been obtained. Pediatric athletes should be symptom-free for several days [
80] prior to starting a gradual return to activity following a stepwise exertion protocol [
5]. Each step should take a minimum of 24 hours [
5,
80,
87]. If any symptoms return, the athlete should rest until symptoms resolve and then try going back to the previous asymptomatic step and be reassessed by a physician.
Specific factors may require modification of concussion management [
5]. These modifying factors may include medications; a history of multiple prior concussions; younger age; and co-morbid conditions such as mental illness, attention deficit hyperactivity disorder, headache disorder, and learning disabilities. The presence of modifying factors may predict the potential for prolonged recovery and require additional management considerations, including formal neuropsychological testing and diagnostic imaging [
5].
Governments are becoming increasingly cognizant of the importance of concussion awareness and are taking steps to improve concussion education. In the United States, the Lystedt Law was passed in 2009 recommending concussion education for athletes, parents and coaches [
88]. In Canada, the Ontario Ministry of Education has mandated that all school boards in the province develop and enforce concussion policies [
89].
Physeal injury
Disturbed physeal growth as a result of acute growth plate injury can result in limb length discrepancy, angular deformity, or altered joint mechanics [
90]. Osteoarthritis may result from chondral damage at the time of growth plate injury, articular incongruity, or joint malalignment [
91,
92].
Epiphyseal injury may present with persistent or severe pain, visible deformity, or an inability to move or put pressure on a limb [
93,
94]. Swelling near a joint with focal tenderness over the physis may also be present. Lower extremity injuries may present as an inability to bear weight on the injured side; upper extremity injuries present with complaints of impaired function and reduced range of motion [
95]. X-rays are typically used to determine whether a growth plate fracture has occurred. However, other diagnostic tests such as magnetic resonance imaging (MRI) or ultrasound, are also useful [
96,
97].
Management of acute epiphyseal plate injury depends on type of fracture. The system most widely used to describe acute growth plate injuries was developed by Salter and Harris (SH) and includes five types of injury [
98]. In minimally displaced SH I and II injuries only symptomatic treatment may be necessary. However, if there is a wide displacement manipulation under anaesthesia with immobilization is indicated. The child is instructed to limit activities that impose pressure on the injured area. These injury types may be associated with growth impairment [
99]. SH III and IV injuries are intraarticular, and operative anatomical reduction most often with internal fixation is necessary depending on patient age, fracture location, intra-articular displacement, and angulation. In these instances, the child needs to be followed up to skeletal maturity. Sometimes a growth arrest line may appear as a marker of the injury. SH V physeal injuries often result in partial or complete growth arrest. As a result, physeal bar resection may be required or other surgical procedures may be necessary to prevent or correct deformity [
100].
Young athletes are also vulnerable to stress-related physeal injuries [
6]. Symptoms of chronic epiphyseal plate injuries include pain on weight-bearing and decreased function. These injuries may not show evidence of abnormalities during early radiographs; however, growth arrest and/or angular malalignment may follow.
Physeal stress injuries are thought to develop when repetitive loading of the extremity disrupts metaphyseal perfusion which in turn inhibits ossification of the chondrocytes in the zone of provisional calcification [
101]. The hypertrophic zone continues to widen as the chondrocytes continue to transition from the germinal layer to the proliferative zone [
102]. Widening of the physis may be seen radiographically, whereas physeal cartilage extension into the metaphysis has been shown with magnetic resonance imaging [
102,
103].
Treatment for physeal stress injury is straightforward: rest from loading of the extremity [
6,
11,
101]. However, in cases involving growth disturbance, corrective surgery may be required [
29,
30].
Physeal injury may also arise from ACL surgery. The current literature now supports the trend toward early operative treatment of ACL injury to restore knee stability and prevent progressive meniscal and/or articular cartilage damage, but the optimal approach to ACL reconstruction in this age group remains controversial [
104]. Despite the reported clinical success of transphyseal reconstruction, iatrogenic growth disturbance secondary to physeal damage remains a genuine concern [
104].