Abstract
In 1902 Shenton described his “line” which, “is formed by the outlines of the upper margin of the obturator foramen and the inner margin of the neck of the femur” stating, “broken continuity of which infallibly indicates displacement or trouble in the hip region. Some 110 years later with significant advancements in Radiology, we assessed whether there is still a role in modern Orthopaedics.
We reviewed 900 anterior-posterior bilateral hips on pelvis radiographs and noted whether Shenton's line was intact or broken. We recorded the presence or absence of pathology in each hip along with age and sex of the patient. In addition 15 independent observers were asked to blindly independently review 15 pelvic radiographs on two separate occasions. They noted whether Shenton's line was intact or disrupted. From this data we analysed the intra and inter-observer reliability.
1547 hips were analysed. 63% (971/1547) had an intact Shenton's line, 37% (576/1547) had a disrupted line. Of 271 femoral neck fractures, 44 (16%) were seen to have an intact Shenton's line. Regarding other pathologies, 2% of osteoarthritic hips, 0.1% of dysplastic hips and 20% of prosthetic hips had a disrupted Shenton's line. No ‘normal’ hips had a broken line. There was significant inter-observer error yet little intra-observer error found.
Our evidence reaffirms Shenton's original work. With a disrupted line there is a high probability of pathology within the hip. However, there may still be a fracture with an intact line, suggesting that Shenton's line is highly sensitive yet not greatly specific.
