Nerve preservation during partial sacrectomy by two-stage anterior and posterior approach: illustrative case.

BACKGROUND: Preserving the neurological function of sacral nerves during total or partial sacrectomy is challenging.

OBSERVATIONS: The authors describe a case of an osseous desmoplastic fibroma of the sacrum in a 51-year-old woman. The patient attended the authors' institution with loss of muscle strength and sensitivity impairment in both legs, gait instability, bowel constipation, urinary incontinence, and weight loss. Preoperative magnetic resonance imaging and positron emission tomography/computed tomography showed intrapelvic and posterior extension of the tumor but sparing of S1 and the sacroiliac and lumbosacral joints. After a multidisciplinary discussion of the case, a staged anterior-posterior approach to the sacrum was chosen. The abdominal approach allowed full mobilization of the uterus, ovaries, bladder, and colon and protection of iliac vessels. After tumor resection, a synthetic surgical mesh was placed over the sacrum to minimize soft tissue defects. Then, the posterior stage allowed the authors to perform a bicortical osteotomy, achieving wide tumor excision with minimal nerve root injury. Spinopelvic fixation was not necessary, because both sacroiliac and lumbosacral joints remained intact. A few days after the surgery, the patient restarted ambulation and recovered sphincter control.

LESSONS: Multidisciplinary planning and a staged abdominal and posterior approach for partial sacrectomy were fundamental to preserve neurological function in this case.