Poster 253: Is the Use of Pretreatment Magnetic Resonance Imaging Necessary Prior to Surgery in Pediatric Tibial Spine Fractures

OBJECTIVES: Injuries to the tibial spine occur as a result of an anterior cruciate ligament (ACL) avulsion fracture from the intercondylar eminence of the proximal tibia. Similar to anterior cruciate ligament ruptures, tibial spine injuries are associated with damage to other intraarticular structures. These associated injuries are often visualized with Magnetic Resonance Imaging (MRI) obtained prior to surgery. The purpose of the study is to describe concomitant injuries visualized by a pretreatment MRI, to examine how this correlates to what is seen at the time of surgery, and to determine how a pretreatment MRI affects the time between injury and surgery as well the length of the surgical procedure itself. Our hypothesis is that a pretreatment MRI results in a longer time between injury and surgery without any affect on operating time or amount of concomitant pathology identified. METHODS: Utilizing an institutional review board approved retrospective study, we identified patients under 18 years of age who underwent arthroscopic management of a tibial spine fracture over a 13 year period. Our exclusion criteria were patients with a concomitant ipsilateral lower extremity fracture or posterior cruciate ligament injury, patients with poor imaging quality, and patients with incomplete medical records. Patients were then categorized based on whether they obtained a pretreatment MRI. We then evaluated for concomitant injuries, time from injury to surgery, total room time, and tourniquet time between the groups. RESULTS: A total of 85 patients met this inclusion criteria, of which 44 (51.7%) had a pretreatment MRI. There were no significant differences in age, gender, or Myers and McKeever grade between groups. All were treated with arthroscopic reduction and fixation. In the MRI group, there were 30 patients (68.2%) that were identified to have additional meniscal or chondral pathology. The three most common pathologies seen on MRI were lateral meniscus tears (13 patients), medial meniscus tears (6 patients), and intermeniscal ligament entrapment (6 patients). In addition, 28 patients (63.6%) were found to have a bone contusion pattern similar to that seen in ACL injuries and 17 patients (38.6%) showed signs of damage to the ACL fibers themselves. Of those 30 patients with meniscal pathology or entrapment seen on MRI, 17 patients (56.7%) were confirmed to have that pathology at the time of arthroscopy. The percentage of patients with meniscal or chondral pathology seen on arthroscopy was not significantly different between those who received a pretreatment MRI and those who did not (38.6% MRI group vs 41.5% No-MRI group p =0.79). The time from injury to surgery was significantly longer in the MRI group (19.3 days vs 10.1 days p=0.01). Both the tourniquet time (72 min vs 76 min) and operative time (83.5 min vs 90.5 min) were not significantly different(p=0.49 for tourniquet time and p=0.32 for room time). CONCLUSIONS: Over two-thirds of patients who sustained a tibial spine fracture were noted to have concomitant pathology on MRI, with 56.7% of injuries seen on MRI correlating to what was seen at the time of surgery. The use of pretreatment MRI was shown to delay surgery without any significant change in operative time, tourniquet time, or percentage of pathology identified at time of surgery. Previous studies have suggested that a pre-treatment MRI may be helpful in identifying pathology, however we believe this is the first study to determine if obtaining a pretreatment MRI influences operative time, tourniquet time, and pathology identified at time of surgery.