Arcuate sign-fibular head avulsion fracture and associated injuries in the pediatric and adolescent population.

ABSTRACT

PURPOSE: To describe the first "arcuate sign" case series in the pediatric population, radiologic features of the associated injuries, management, and how they compare with the adult population. METHODS: Retrospective study included patients under 18 years of age with a classic "arcuate sign" on radiographs. Data collected included patient demographics, mechanism of injury, and management. Radiographs and advanced imaging (MRI, CT) were reviewed by two musculoskeletal radiologists in a blinded fashion and findings recorded. RESULTS: Seven patients (4 males, 3 females) with mean age 15 years (range 14-17 years) were included in the study. All 7 injuries were related to sports, 5/7 (71%) being non-contact injuries. Five patients had MRI done-1 LCL injury, MPFL sprain, and MCL sprain were reported; 3 popliteofibular ligament and popliteus sprains were seen; and 3 bone contusions were present on imaging. None of the patients had meniscus or cruciate ligament tears. One patient had an additional fracture of the lateral tibial plateau at the ilio-tibial band attachment and an associated peroneal nerve injury. Five out of seven (71.4%) were treated non-operatively and were able to return back to activity at a mean of 7.2 weeks from injury. Two out of seven (28.6%) needed operative intervention for the fracture but not arthroscopic repair. CONCLUSION: Pediatric patients with a radiographic arcuate sign tend not to have ACL, PCL, or meniscal injuries, and treatment is predominantly non-operative in contrast to literature reported in adults.