Location and Radiological Features of the Synovial Pit and Its Usefulness in Hip Arthroscopy
Abstract
Introduction: The synovial pit is a cystic lesion or notch in the femoral neck, initially regarded as an incidental finding but more recently associated with femoroacetabular impingement (FAI). It is observed in approximately 5% of the general population, with a higher prevalence in men, and in up to 33% of patients with FAI. Its identification is clinically relevant given its association with labral and articular cartilage damage, although its origin may be related to both femoral (cam) and acetabular (pincer) morphological abnormalities, making it difficult to attribute to a single cause. Materials and Methods: A total of 388 hip arthroscopies performed between 2018 and 2023 were included. Radiographs and complementary imaging studies were analyzed to classify morphological abnormalities and describe synovial pit characteristics. Measurements included the lateral center-edge angle, acetabular index, and alpha angle. Results: In patients with predominantly femoral abnormalities, impingement tended to occur more proximally, and the synovial pit was located in that region; conversely, when acetabular abnormalities predominated, impingement occurred more distally. No other variables reached statistical significance. Conclusion: The presence and features of the synovial pit in preoperative imaging, as well as its intraoperative identification during hip arthroscopy, may provide additional insight into the mechanisms of femoroacetabular impingement and its biomechanics.Downloads
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