Central Acetabular Osteophytes

Central acetabular osteophytosis has been shown to represent an early radiological manifestation of hip osteoarthritis and has recently been been likened to a saber tooth. These osteophytes arise from the acetabular notch above the transverse ligament and progress to involve the acetabular notch circumferentially or even to occlude the acetabular notch completely, resulting in lateralization of the femoral head.

The above image reveals advanced osteoarthritis of the left hip joint with a large central osteophyte that almost completely bridges the acetabular notch and results in mild lateralization of the femoral head.

References

• Varich L, Pathria M, Resnick D, Hodler J, Bruser D, Bosch E, Trudell D, Tyson R. Patterns of central acetabular osteophytosis in osteoarthritis of the hip. Invest Radiol. 1993 Dec;28(12):1120-7.
• Mofidi A, Shields JS, and Stubbs AJ. Central acetabular osteophyte (saber tooth sign), one of the earliest signs of osteoarthritis of the hip joint. Eur J Orthop Surg & Traumatology. Published online, July 24, 2010.