A Rare Symptomatic Pelvic Rib - A Case Report

Abstract

Introduction: A pelvic rib or pelvic finger is a benign and unusual congenital entity of hip with a finger or rib like bone formation in soft tissues around pelvis. It is generally asymptomatic and incidentally discovered in a plain radiograph. This is a very rare but not unknown entity.

Case report: A 25-year-old male reported to our institution with dull aching pain over right hip and abduction gait, then followed up the radiograph and magnetic resonance imaging, in which there was a osteochondroma like lesion in medial aspect of lesser trochanter of right proximal femur was seen. Surgical excision of the lesion was done and sent for histopathological study in which pelvic rib was confirmed.

Conclusion: The real challenge is diagnosis of this condition with its differentials i.e. heterotrophic ossifications around hip, osteochondroma, post-traumatic ossification, or avulsion injuries in and around hip joint This entity should be in mind of radiologists, orthopedic surgeons, and orthopedic onco-surgeons for differential diagnosis of chronic hip pain to avoid unnecessary investigations and procedures.

Keywords: Pelvic rib; hip pain; pelvic finger.

Figure 1

A plain pelvis anterior posterior radiograph showing bony protuberance on the right lesser trochanter extending towards ischial tuberosity.

Figure 2

3D Reconstruction computed tomography images showing the pelvic rib around the lesser trochanter of right hip.

Figure 3

Coronal cuts of 2D showing bony protuberance at lesser trochanter of right hip.

Figure 4

Magnetic resonance imaging images showing the bony lesion in sagittal and coronal cuts in right hip.

Figure 5

Lithotomy position with complete draping with Incision mark at medial aspect of right thigh.

Figure 6

Exposure through the line of incision and exposure of the bony prominence in the medial aspect of right thigh.

Figure 7

Excised pelvic rib with measuring scale.

Figure 8

Histopathological image of the excised lesion.