Retroperitoneal Psoas Bursa

bursa m. psoatis (pars retroperitonealis)

A potential space between the posterior psoas fascia and the anterior lumbar vertebral bodies and transverse processes, forming the retroperitoneal psoas compartment. This space is the anatomical corridor for psoas abscess propagation from vertebral osteomyelitis, Crohn's disease, and retroperitoneal infections.

Region: Abdomen

Clinical Relevance

Clinical Notes

The retroperitoneal psoas bursa space is the route of spread for psoas abscess, which may be primary (haematogenous, often S. aureus) or secondary (from adjacent spinal, colonic, or renal infection). The abscess tracks within the psoas fascia to present in the iliac fossa, inguinal region, or femoral triangle. CT-guided drainage or surgical evacuation is required. The psoas compartment is also the target for psoas block (quadratus lumborum block) for lumbar and hip analgesia.

Pathology

Common Injuries & Conditions

Psoas Abscess

Pyogenic or tuberculous infection within the retroperitoneal psoas compartment producing flank pain, fever, and an antalgic hip flexion posture, tracked by CT from its origin (spinal, colonic, or renal) to its presentation site in the groin.