Abstract
Background and Purpose: Anterior cruciate ligament (ACL) injuries are among the most common in sports, and can severely impair function and quality of life. Restoration of strength to pre-operative levels can have significant impact on return to sport and pre-injury activities. Unfortunately, a number of post-operative resistance and exercise restrictions are placed in order to limit the amount of stress placed on a joint. Since high resistance, or 70-85% of an individual’s 1-repetition maximum (1-RM), is typically required for muscle training to achieve muscle hypertrophy and increases in muscular strength, restrictions on resistance can slow the strength recovery process. Blood flow restriction (BFR) training facilitates muscle hypertrophy at low resistance levels (as low as 20-30% 1-RM) providing a viable alternative to traditional low-resistance, high repetition activities that are performed post-ACL surgery. The purpose of this case is to examine the viability of BFR training as a treatment modality in the post-operative management and rehabilitation of an ACL reconstruction and meniscus repair in a young, female soccer player. Case Description: The patient is a sixteen-year-old female athlete who tore her ACL and lateral meniscus while playing soccer. Patient participates in numerous activities, therefore functional status from an activity-participation standpoint was greatly impaired. She underwent a left ACL reconstruction along with meniscus repair. This was the patient’s second ACL reconstruction (first was on the right knee). Patient was compliant with all aspects of physical therapy and was consistent in her attendance. Outcomes: Patient demonstrated increases in thigh girth, from 40 cm to 41.5 cm, to 42 cm in the affected lower extremity at 0 weeks, 4 weeks, and 8 weeks, respectively. Patient also demonstrated improvement in functional strength per decreased quadriceps lag during straight leg raise with the affected lower extremity, and improvement of manual muscle testing strength at 4 weeks (4- out of 5) and at 8 weeks (4+ out of 5). Lastly, patient increased knee flexion range of motion from 85 degrees to 102 degrees to 130 degrees in the affected lower extremity at 0 weeks, at 4 weeks, and at 8 weeks, respectively. Patient outcomes were on par with expectations for the injury and all rehabilitation goals were met for the allotted timeline. Given time constraints of this case report, patient was not yet cleared for high-level, sport-specific activities. Discussion: Blood flow restriction training coupled with therapeutic exercise proved to be an effective treatment modality as part of a comprehensive ACL reconstruction and meniscus repair protocol. Patient experienced no setbacks and is expected to make a full recovery and full return to sport within the typical 9 to 12-month recovery time.