Superficial Anatomy of the Female Sacroiliac Dimples

Description

Paired sacroiliac dimples, also termed the dimples of Venus or fossae lumbales laterales, sit symmetrically over the posterior pelvis just lateral to the midline and slightly inferior to the iliac crests. Each cutaneous depression corresponds closely to the posterior superior iliac spine (PSIS), with the sacrum and superior end of the natal cleft lying medial and inferior. Superficial contours of the lower lumbar region frame the landmark, and the overlying skin and subcutaneous tissue taper into the dimple where fibrous septa tether the dermis to the underlying fascia. A clean surface landmark. Clinicians rely on these dimples when palpation of deep bony anatomy is limited by habitus or soft tissue swelling. Locating the PSIS helps approximate the level of S2 and the posterior sacroiliac joint line, guiding examination for sacroiliac dysfunction, pelvic girdle pain in pregnancy, and focal tenderness in inflammatory sacroiliitis. The same relationship is used during image guided and landmark based planning for posterior SI joint injections or radiofrequency procedures, where an accurate starting point on the skin reduces needle redirection and improves reproducibility between sides. Course directors in gross anatomy, surface anatomy, and musculoskeletal physical examination will find this posterior female view well suited for teaching pelvic palpation, symmetry assessment, and documentation of landmarks in standardized patient settings. Medical publishers can pair it with low back pain chapters, rehabilitation manuals, or interventional pain guides that discuss the PSIS, sacroiliac joint, and posterior pelvic ring orientation. Anatomical accuracy verified by SciePro's Medical Advisory Board.