Pediatric rehabilitation has to be performed in close collaboration between the parents, an experienced physiotherapist, and the orthopedic surgeon. Exercises and goals have to be adjusted compared to traditional rehabilitation protocols because children cannot be expected to perform unsupervised training independently. Rehabilitation exercises are less focused on muscular strength and hypertrophy, while the primary focus should be neuromuscular stimulation and maintenance of multi-joint functional stability [9, 29]. Inability to be active in preferred activities or repetitive episodes of giving way despite undergoing an adequate rehabilitation program will point toward advising an ACL reconstruction before skeletal maturity. Additionally, children who have a secondary repairable meniscus injury will usually undergo a meniscus repair with concomitant ACL reconstruction, as this is assumed to improve the prognosis of the meniscus repair [14]. We also find it imperative that the child and parents are provided with thorough information on the benefits and risks involved with both surgical and conservative treatment, including the option of continuing sports involving less pivoting motions until skeletal maturity is reached, when a reconstruction involving less risk can be performed.

Modern rehabilitation is progressed through phases or stages based on sound clinical reasoning, sequenced functional achievements, and the completion of functional milestones. At the same time, knowledge on tissue-specific biologic healing processes should be respected and will guide the timeline of progression. Throughout the rehabilitation process, a structure with four phases is often used to guide the aims and content of the progression (Fig. 7.2). Within each phase, specific functional milestones and achievement goals are identified. Some goals will be primary in each phase, for example, achieving full knee extension and quadriceps activation early after the knee injury in phase 1. Throughout the first two phases, the child should be guarded from pivoting activities and possibly also wear a protective brace in school and training. Exercises to facilitate proper alignment and adequate landing techniques have been successfully implemented in injury prevention programs [15, 22, 36] and are recommended through phase 2 and 3 of pediatric ACL rehabilitation.

The child and parents should consult their physical therapist regularly. A normal setup could be once a week throughout phase 1, every second week through phase 2, and once a month in phase 3. Rehabilitation usually should be designed to enable performance at home, and it is recommended to limit the number of exercises to enhance the feasibility and adherence to the program [7].