It is frequently difficult to diagnose and treat of malignant sacral bone tumors. This tumor is diagnosed with lumbar disc hernia, instability coccygitis, hemorrhoids. We reviewed the surgical treatment of primary malignant (14) and secondary (metastatic) sacral tumors (11) in 25 patients from 1983 to 2000. Primary tumors consisted of chordoma in 11 patients, chordoma with spindle cell sarcoma, malignant peripheral nerve sheath tumor (MPNST), giant cell tumor of bone in 1 patient each. The secondary tumors consisted of invading carcinoma in 7 patients, metastatic carcinoma in 4 patients. Location of the sacral tumor was showed total sacrum in 2 patients, below S2 in 18, S3 in 2 and S4 in 3. Preserving nerves were L5 in 1 patient, S1 in 17, S2 in 2, S3 in 3, and 2 performed curettage. Posterior approach was used in 8 patients, and an anterior and posterior combined approach in 17. Sacrectomy only in 7 patients, and sacrectomy and colostomy in 8, including with rectum was performed in 8, and 2 patients had extensive curettage and bone graft or hydroxyapatite (HA) transplantation. Six tumor excisions were used modified T-saw which pass through the sacral canal preserving nerve roots. Surgical margin of chordoma in primary sacral tumors had wide in 10, wide excision with partial contamination in 2, except curettage in 1. MPNST had curettage and giant cell tumor of bone had marginal in 1 each. Secondary sacral tumors had wide in 9, marginal in 2.

Adjuvant therapy was used radiation therapy in 3 patients and chemotherapy in 2 and ethanol in 1. Musculocutaneous flap was reconstracted tensor fascia lata flap and gluteal muscle flap in 2 patients. Interval between initial chief complaints and diagnosis of chordoma detected from 6 months to 10 years, avarage 5 years 3 months by rectal examination, radiogram, genital ultra echo and MRI; invading carcinoma from 2 months to 3 years, avarage 8 months, and metastatic carcinoma from 2 months to 4 months, average 3 months. Six of 12 patients of chordoma in primary sacral tumors are alive from 6 months to 18 years, average 4 years 6 months; remaining patients were died 6 month to 8 years, average 3 years 2 months, except 2 patient died with infection. The patient with a MPNST died after 2 years 6 months, and a giant cell tumor of bone had no recurrence or lung metastases in 10 years.

One of 11 patients of secondary sacral tumor (initial surgery) is alive in 14 years 6 months, remaining 10 patients died 3 months to 4 years 6 months, average 1 year 10 months, except 2 patients died with infection. Complications were much bleeding, infection, skin slough, nerve injury. We recommend better surgical method that anterior and posterir approach use above S3, and posterior approach blow S4, A modified T-saw performed an osteotomy of the pars lateral of the sacrum, proved to be easier and faster than osteotomies performed using the old method.