OTA 33-B1 intra-articular fracture of the distal femur of the lateral femoral condyle involving both weight-bearing and non-weight-bearing surfaces after acute patellar dislocation: a case report and literature review

Background Concomitant patellar dislocation with OTA 33-B1 intra-articular fracture of the distal femur involving both weightbearing and non-weightbearing lateral femoral condyle fracture is a rare entity, with few case reports in the literature, and no standard approach to its treatment. In this study we review previous cases along with describing one patient presenting to our institution. Methods A systematic literature search in PubMed/MEDLINE and Web of Science was conducted using the key words “patella dislocation,” "medial patellofemoral ligament injury”, “OTA 33-B1 lateral femoral condyle fracture” to retrieve related articles. Data extracted included patients’ demographics (age, sex),injury mechanism, type of dislocation, location of fracture, treatment modality, and outcome. In addition, a detailed description of the course of this patient's disease is presented and discussed. Results This study included 7 patients including reported literature in previous publications as well as one primary case from our own institute. The mean age of the patients was 19 years, with most fractures involving the weight bearing area of the lateral femoral condyle(OTA 33-B1).Based on the symptoms compared, injury mechanism, management modality and outcome. This study provides more information on this rare type of fractures from a clinical point of view which may be useful in diagnosis as well as treatment planning and further research studies. Conclusions Injuries to the lateral femoral condyle(OTA 33-B1 intra-articular fracture of the distal femur), involving both weightbearing and non-weightbearing portions are extremely uncommon sequelae of a patellar dislocation. The mechanism of injury is probably due to direct impaction of the patella with additional shear stress imparted by the tibial plateau. Resulting in comminuted fragmentation of the bones in these articulations.