CC BY-NC-ND 4.0 · Indian J Radiol Imaging 2022; 32(04): 505-509
DOI: 10.1055/s-0042-1755253
Original Article

Lateral Femoral Condyle CRATER sign of BRIK an Ancillary Sign of Lateral Patellar Dislocation

1   Departments of Orthopedics, Southport and Ormskirk NHS trust, Southport, United Kingdom
Kanaka Durga Prasad Bhamidipaty
2   Departments of Radiology, GITAM Institute of Medical Sciences & Research (GIMSR), Vizag, India
Rajesh Botchu
3   Departments of Musculoskeletal Radiology, Royal Orthopaedic Hospital, Birmingham, United Kingdom
› Author Affiliations
Funding None.


Introduction Acute lateral patellar dislocation is a common knee injury pattern. However, coincidental osseous defect may be present in normal knees.

Purpose Evaluate the characteristics of osseous bone defect and describe a new ancillary sign associated with lateral patellar dislocation.

Materials and Methods Magnetic resonance imaging (MRI) of 50 consecutive patients referred following a traumatic lateral patellar dislocation of the knee joint and 50 patients with knee pain without MR features of patellar dislocation were obtained for evaluation over a 7-year period. They were analyzed for location of bony defects in the periarticular region.

Results Of the 50 patients who underwent MRI following a reduced traumatic lateral patellar dislocation, 3 patients had an osseous “crater” of more than 2 mm in depth on the non-articular surface of the lateral femoral condyle. None of control group of patients had an osseous defect measuring more than 2 mm in depth.

Conclusion This associated finding of an osseous “crater” of more than 2 mm on the non-articular surface of the lateral femoral condyle following traumatic lateral patellar dislocation is a rare occurrence. We highlight this as an ancillary sign of lateral patellar dislocation necessitating careful evaluation (Crater sign of Bhamidipaty Rajesh Iyengar Kartik [BRIK]). The presence of lateral femoral condyle “CRATER” sign of BRIK on MRI undertaken for other reasons in the knee, in the absence of osseous edema may suggest a past episode of severe, reduced patellar dislocation.

Publication History

Article published online:
30 August 2022

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