Purpose: Cage fusion of the L5–S1 segment is a controversial issue due to the weak stabilisation of the spine during extension and axial rotation. Complementary fixation appears to be needed to improve stability, but the presence of the bifurcation of the great vessels is an anatomic limitation. We studied the anatomy of this area to examine the feasibility of anterior plate fixation.

Material and methods: According to the recognised anatomic references (Rouvière, Bouchet and Cuilleret, Louis), a 33-mm safety zone was described at the aortoiliac and iliocaval bifurcation. This space free from contact with the greater vessels lies in front of the L5–S1 disc. Pre-operative angio-MRI was used to assess the size of this safety zone. A triangular anterior plate was designed for arthrodesis (Pyramid Sofamor Danek, USA). An L5–S1 arthrodesis was performed in 15 consecutive patients using this plate. Follow-up was one year. A video-assisted anterior retroperitoneal approach was used in all cases. The Prolo and Oswestry scores were used for the preoperative and last follow-up evaluations.

Results: According to the anatomic study and the MRI views, 89% of the patients had a sufficient safety zone for plate fixation. The method was contraindicated in two patients who had a low bifurcation. Angio-MRI was found to be simple and reproducible. The MRI analysis was confirmed at surgery (no false negatives). The plate was successfully implanted in 15 patients with no contact with the great vessels. There were no serious complications (vascular, neurological, urological, digestive). The economic Prolo score was improved from 2.7 to 4.2 and the functional score from 2.6 to 4.3. The Oswestry score improved 33%. The rate of clinical success was 93% (14/15 patients).

Discussion and conclusion: Implantation of an anterior plate for L5-S1 fusion is feasible. The key points are: 1) rigorous preoperative evaluation of the greater vessel bifurcation; 2) anatomic plate design; 3) appropriate surgical technique. The risk of retrograde ejaculation is related to retraction of the hypogastric plexus and should be investigated with a prospective study. This osteosynthesis technique can avoid secondary operations for fixation with pedicular or transarticular screwing.

Purpose: Thoracoscopic spinal surgery may be less aggressive than classical open surgery. We relate our experience over the last five years, analysing complications observed.

Material and methods: Between 1995 and 2000, 68 patients underwent thoracoscopic spinal surgery. There were 34 men and 34 women, mean age 30.2 years (13–69). We analysed indications, preoperative anaesthesia parameters, peroperative and postoperative parameters and pulmonary, vascular, neurological and instrumental complications.

Results: Indications were: metastatic compression in three patients, disc herniation in eight with five calcified discs, fracture in 25, anterior release for scoliosis in 32 with inter-somatic graft in 20. Mean duration of the hospital stay was 19.6 days (7–48). There were three fractures with lung contusion that were excluded from the analysis although thoracoscopic surgery was possible. The analysis thus included 61 right and four left thoracoscopies. Four to nine trocars were used. There were three cases of intercostal nevralgia. Operation time depended on the underlying disease: 18 min for scoliosis, 2 hr 40 min for fractures, 4 hr 15 min for discal herniation (2 h 20–7 h 15). Blood loss was less than 200 cc for scoliosis, a mean 533 cc for fractures, and 800 cc for metastases. There were no pulmonary, vascular or instrumental complications. The image amplifier was used to monitor all osteosyntheses. We had one patient whose neurological situation worsened after resection of a transdural calcified thoracic herniation. Stay in the intensive care unit after surgery was 3.4 days, the drain was removed at 3.26 days and had collected 1240 cc. Postoperative paint was assessed for patients who had undergone thoracoscopy alone and who had no other disease (19 fractures and 8 herniation cases). level three antalgesics were required for 3.2 days. There were no vascular complications or signs of phlebitis. One residual atelectasia of the lower right lobe occurred in a female patient with major traumatic contusion, and pleural effusion was observed in three. One patient developed a contralateral pneumothorax that was punctured after release of major scoliosis (Cobe 92°). Residual pleural effusion after withdrawing the drain was aspirated at 48 hours. There were no infections.

Discussion: Thoracoscopy allowed the planned procedure in all patients. Blood loss was much lower than with classical open surgery. Pain was controlled better and the cosmetic effect was exceptional. Function was recovered rapidly by fracture patients. the quality of the anterior release for the scoliosis patients was equivalent to that obtained with classical techniques.

Conclusion: The complication rate was lower than that usually observed for similar procedures using classical techniques.