Purpose of the study: This study was conducted to assess short- and mid-term radiographic outcome of percutaneous posterior osteosynthesis (Sextant®)of thoracolumbar spine fractures and to identify indications and complications.

Material and methods: The Sextant® material was used for 14 patients with a lumbar spine or low thoracic spine fracture. Mean patient age was 40 years (range 19–84). Outcome was reviewed retrospectively. Osteosynthesis was performed for 11 fractures Mager 1 A3, 2 B2, 1 C1 with no neurological deficit. A complementary graft and anterior decompression were used 11 times (9 fibular, 1 posterior crest + rib, 1 cage). The pre- and postoperative and 3 month ART were noted. The position of the implants was assessed on the postoperative CT.

Results: Mean follow-up was 9.2 months (range 2–16). On average, ostheosynthesis was performed 15 days after trauma (range 1–90 days). There were no neurological or infectious complications. Sutures had to be resected in two cases due to cutaneous suffering. Nine patients wore a corset for three months. The absolute ART score improved from 18 preoperatively to 7 postoperatively and was noted at 14 at three months. Seven patients required heterologous blood transfusion after the anterior approach. Three screws (5.3%) were ectopic but without consequence.

Discussion: Indications for percutaneous osteosynthesis include spinal fractures without neurological complications with sagittal deformation for which an anterior approach is planned initially for mechanical reasons. An isolated anterior approach is possible in this type of fracture; nevertheless, percutaneous posterior osteosynthesis enables emergency reduction and fixation of the fracture, a simplified secondary minimal anterior approach for release, and bone grafting without anterior instrumentation. Three patients did nor require complementary anterior stabilization as the percutaneous oseosynthesis played the role of «internal fixation». The advantages of percuteneous osteosynthesis are the absence of bleeding and damage to the paravertebral muscles which limits morbidity, particularly infection. This technique can be performed in the emergency setting, especially for multiple trauma victims. The drawbacks of percutaneous osteosynthesis are the impossibility of performing a posterior fusion and release the spinal canal. The loss of correction observed were probably related to the type of graft (fibular). Use of a cage should limit graft impaction and loss of correction.

Purpose: Surgery is required for primary tumours invading the sacroiliac joint. The purpose of the present work was to analyse results obtained with surgical treatment in order to better ascertain indications.

Material and methods: Forty patients (24 men and 16 women), mean age 24 years (range 12–56) underwent surgery for high-grade sarcoma (n=30, osteosarcoma 12, Ewing 13, chondrosarcoma five) or more differentiated tumours (n=10, low-grade S chondrosarcoma five, fibro-sarcoma two, others three). Resection was achieved in 37 cases via two approaches and via a lateral approach in three. Resection involved vertical sacrectomy either via the homolateral foramen (n=27) or via the midline (n=10). Reconstruction consisted in stabilising the iliosa-cral assembly generally associated with vertebral osteo-synthesis, an autologous graft in 36 cases, cement in one, and an allograft in three. Functional outcome was assessed with the MSTS (Enneking).

Results: There were three infections (all three with extensive lateral approach) and five cases of postoperative lumbosacral trunk palsy. Late complications were three cases of spondylolisthesis and eight nonunions. Twenty patients died (eight local recurrences, ten metastases, one chemotherapy toxicity, one undetermined cause). Sixteen patients achieved complete remission at six years (follow-up 2–16 years) and four patients were lost to follow-up. Functional outcome was very good in eight, good in ten, fair in twelve, and poor in ten. Survival was 40% among patients with malignant tumours (38 patients) but only 20% for those with osteosarcomas.

Discussion: Technical improvements (combined approach rather than wide lateral approach and omentum flap) have allowed a reduction of cutaneous and infectious complications. Mechanical complications can be prevented by systematic lumbosacral fusion on the side opposite the resection reconstruction. This provides good functional results despite sacrificing a hemi-sacral plexus if the lumbo-sacral trunk is preserved. Reconstruction after extension of the resection to the acetabulum raises an unresolved problem and yields mediocre results. The quality of the surgical resection is determinant since risk of local recurrence is 8/100 after a contaminated resection edge.

Conclusion: Surgical resection of sacroiliac tumours is a source of numerous complications despite real technical improvements. This approach can be proposed if carcinological resection can be reasonably achieved. Local control is very poor in case of large osteo-osteogenic sarcomas.