Sacral Insufficiency Fractures After Total Pubectomy for Osteomyelitis: A Case Series

Objective: To document the incidence, risk factors, and prevalence of sacral insufficiency fractures (SIF) among patients who have undergone total pubectomy for osteomyelitis. Methods: A retrospective chart review was performed of patients undergoing total pubectomy for osteomyelitis at a single institution from 2016 to 2021. Descriptive statistics and univariate analysis were performed using the Wilcoxon rank-sum test and Fisher exact test as appropriate. Results: Sixteen patients underwent total pubectomy for osteomyelitis. The median age was 68 years. 12 of 16 (75%) had previously received pelvic radiotherapy. The median BMI was 27.8 kg/m2. Eleven (68.75%) had postoperative pelvic imaging, of which 3 (27.3%) had a new SIF. One other patient had a SIF 3 days before pubectomy. Three SIFs were detected via MRI and 1 by CT scan. The median BMI of patients with SIF was significantly lower than those without SIF (22.4 vs 30.5, P =.004). All patients with SIF presented with new pelvic or perineal pain without radiculopathy. Symptoms resolved for three patients with non-opioid analgesics, physical therapy, and/or a brief trial of opioids. Conclusion: Sacral insufficiency fracture is a rare sequela of total pubectomy for osteomyelitis. Lower BMI is significantly associated with SIF perhaps due to reduced muscle mass or poor bone condition and, as a result, baseline pelvic instability. Medical management should be first-line therapy.