AB0041 TO ESTIMATE THE PREVALENCE OF ACETABULAR OSSIFICATIONS IN THE ADULT POPULATION WITH ASYMPTOMATIC, MORPHOLOGICALLY NORMAL HIPS AT CT AND TO DETERMINE WHETHER THE PRESENCE OF LABRAL OSSIFICATIONS IS ASSOCIATED WITH PATIENT-RELATED OR HIP-RELATED PARAMETERS

Background: In clinical practice, ossifications adjoining the acetabular rim are frequently seen in healthy-appearing hip joints, at all ages. The origin of these (ARO) is unclear. While ARO have been described by some authors as variants that may mimic marginal osteophytes, others hypothesized be cause or consequence femoroacetabular impingement. Overall, literature on limited, particular healthy population, and their characteristics not fully understood. Objectives: To estimate prevalence adult population with asymptomatic, morphologically normal hips CT to determine whether presence associated patient-, hip-related parameters. Methods: We prospectively included patients undergoing thoracoabdominal over a 3-month period. After exclusion history pathology and/or signs osteoarthritis CT, we total 150 from 75 patients. analyzed size around rim. relationships between patient-related (sex, age, BMI), parameters (joint space width, cam- pincer-type impingement morphology) were tested using multiple regression analysis. Results: this non-osteoarthritic was 96% (95%CI=[80.1;100.0]). correlated right left (Spearman coefficient=0.64 (95%CI=[0.46;0.79]),p<0.05)).The significantly age (p<0.0001) but BMI (p=0.35), gender (p=0.05), joint width (p≥0.53 for locations) any qualitative quantitative morphology (p≥0.34). Conclusion: Acetabular highly prevalent Their except age. These findings suggest rim, when present isolation, should considered morphology. References: [1]J. W. T. Byrd, K. S. Jones, C. R. Freema. Surgical Outcome Pincer Femoroacetabular Impingement With Without Labral Ossification. Arthroscopy 2016; 32: 1022–1029. [2]P. D. Byers, A. Contepomi, Farkas. A post mortem study joint. Including features side. Annals Rheumatic Diseases 1970 ; 29: 15–31. [3]S. Ninomiya, Shimabukuro, Tanabe, Y. Kim, Tachibana. Ossification labrum. Journal Orthopaedics Science 2001; 5: 511–514. Table 1. Association average severity patient-related, Regression coefficient p- value Patient-related 0.02 0.35 Age 0.04 <0.001 Gender -0.43 0.05 Joint Apical 0.17 0.53 Supero-medial 0.65 Supero-lateral 0.06 0.82 Cam morphotype Angle alpha 45 0.00 0.81 Offset 0.09 0.34 version angle -0.01 0.83 Lateral center-edge 0.56 index 0.03 Crossover sign 0.26 0.41 Posterior wall -0.25 0.47 Figure Coronal reformats examinations showing different sizes labral posterosuperior quadrant (arrows). (a) No ossification, (b-c-d-e) Increasingly large ossification right. Two lines visible location formed contour (double line-sign). Disclosure Interests: None declared