Prevalence, Mechanisms, and Return to Sport After Isolated Popliteus Injuries in Athletes: A Systematic Review

BACKGROUND: Injuries to the posterolateral corner of the knee are commonly reported in athletes, although the prevalence of isolated injuries to the popliteus in athletes is largely unknown. PURPOSE: To systematically review the literature to better understand the prevalence, mechanisms, sporting activities, tear characteristics, management, outcomes, and return-to-sport rate and timing in athletes who have sustained isolated popliteus injuries. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the authors searched the PubMed, OVID, MEDLINE, Biosis Previews, SPORTDiscus, PEDRO, and EMBASE databases for studies from January 1988 to August 2021 on athletes who sustained isolated popliteus injuries during sporting activities. RESULTS: A total of 19 studies consisting of 27 athletes with isolated popliteus injuries sustained during sport were identified. The mean athlete age was 19.9 ± 10.5 years, while 89% (n = 24/27) were male. Traumatic/contact mechanisms were reported in 67% (n = 18/27) of injuries, with American football and soccer being the most common sports. Lateral-sided knee pain was the most frequent complaint, with 85% (n = 23/27) of athletes reporting swelling. Avulsion injuries off the lateral condyle were present in 67% (n = 18/27) of cases. Nonoperative management was performed in 52% (n = 14/27) of athletes. Operative treatment consisted primarily of arthroscopic or open fixation of the osseous fragment. When reported, all athletes successfully returned to sport at a mean of 10.8 ± 8.2 weeks after injury. CONCLUSION: Isolated injuries to the popliteus remain rarely reported in athletes, and athletes are typically evaluated after they experience forced external rotation of the tibia relative to the femur, present with lateral-sided knee pain and effusion, and undergo a stable ligamentous examination. Injuries occurred primarily in male athletes and were the result of traumatic/contact mechanisms, most commonly involving avulsion injuries off the lateral femoral condyle.