Chronic Pelvic Osteomyelitis

A 38-year-old man with spina bifida and paraplegia presented with a five-year history of a decubitus ulcer of his right groin. He had undergone two prior debridements of soft tissue but foul-smelling drainage was persistent. The ulcer measured 3×3×6 cm in depth, and deep biopsy cultures grew Streptococcus viridans, Peptostreptococcus spp., and Bacteroides eggerthii. Magnetic resonance imaging (MRI) confirmed osteomyelitis of the iliac crest) (Fig. 1), and he was treated with a six-week outpatient course of ertapenem. Three weeks after completing the ertapenem, he presented again with a temperature of 104°F and a white blood cell count of 19.8×10⁹/L. The ulcer had decreased in size (2×1.5×6 cm) (Fig. 2A), and drainage had ceased. However, MRI revealed progressive destruction of the right iliac crest and wing. Bone cultures yielded no organisms. Treatment by wide surgical debridement of the iliac crest, negative-pressure wound therapy, and a second six-week course of ertapenem at home resulted in no further infections during one-year followup, but the ulcer remained non-healing (Fig. 2B).

OPEN IN VIEWER

FIG. 1.

Magnetic resonance imaging (MRI) of pelvis showing sinus tract (arrow) with extensive involvement of underlying soft tissue and ilium.

OPEN IN VIEWER

FIG. 2.

Views of ulcer. (A) Prior to surgical debridement of soft tissue and bone. (B) After surgical debridement.

Osteomyelitis of the pelvis can result from direct trauma, post-operative infection, decubitus ulcers, or hematogenous dissemination [1,2]. Diagnosis is based on clinical suspicion coupled with imaging. Most infections are polymicrobial, and the most frequent pathogens are Staphylococcus spp., Pseudomonas aeruginosa, and B. fragilis [2]. Management includes debridement, antibiotics tailored to the inciting pathogens, and wound care. If prolonged intravenous antibiotic therapy is unsuccessful, surgical intervention is warranted. This can be as minimal as soft tissue debridement with or without local bone debridement or as extensive as hemipelvectomy or even hemicorporectomy. A standard hemipelvectomy includes a lower-extremity amputation, whereas an internal hemipelvectomy allows anatomic limb salvage, albeit without function. The incision can either be left open or managed with flap closure. In a series of eight patients undergoing hemipelvectomies for severe decubitus ulcers, the 30-day mortality rate was 25%; however, quality of life was improved for the survivors [3]. Rarely, hemicorporectomy can be used to treat terminal pelvic osteomyelitis. Although hemicorporectomy is extremely morbid, there are reports of patients surviving more than 20 years after surgery [4].