Purpose: We report the operative technique and preliminary results for percutaneous osteosynthesis in the supine position with computed tomography guidance for acetabular fractures without joint displacement.

Material and methods: This prospective study conducted in a single unit included a consecutive non-randomised series of 55 patients who underwent surgery for an unstable pelvic injury between June 1996 and December 2000 under computed tomography guidance. In ten cases, the radiographic and computed tomographic analysis demonstrated a coronal fracture of one of the columns without joint displacement accessible for anteroposterior screw fixation. There were eight men and two women, mean age 35 years.

Surgery: the ten patients were operated on in the supine position, in the scanner room under the same aseptic conditions as in the operation room. The reference computed tomography slice was the Corse slice. The femoral vasculo-nervous bundle was identified. A threaded guide wire was inserted perpendicuallary to the fracture line, anteriorly to posteriorly (Cap Corse technique). A perforated screw with a 7.3 mm diameter was used to fix the fracture. Minimal post-surgical surveillance was 48 hours. Weight bearing was not authorised for six weeks to three months. Al patients were followed prospectively, and mean follow-up ws 16 months (12–36).

Results: Traction was lifted immediately after surgery in all cases. All the patients got up the day after surgery. Mean hospital stay was less than five days postoperatively in all cases. There were no complications (vascular, neurologic, infectious) and no secondary displacement. At last follow-up, he Postel Merle d’Aubigné score was 18 for eight patients, 16 for one and 14 for one. Two patients showed radiographic signs of degenerative hip disease.

Discussion: This percutaneous osteosynthesis method using computed tomographic guidance is reliable (100% well positioned screws) and avoids the need for traction in bed. Morbidity is low (no complications). Even though these eight patients did not present clinical and radiographic signs of osteoarthritis, this technique did not avoid the risk of degenerative hip disease in two patients.

Conclusion: An alternative to traction, percutaneous osteo-synthesis with computed tomographic guidance performed in the supine position for acetabular fractures is a cost-effective procedure.

Recent developments focus on a minimal-invasive approach to the thoracic spine with thoracoscopy. Very often it is necessary to collapse the lung in order to expose the thoracic spine. This technique cannot be used on patients with reduced pulmonary capacity or pleural adhesions. We are trying to use a semi- open technique to combine the advantages of open and thoracoscopic surgery.

The semi-open technique requires a 5 cm incision over the 10th rib with or without partial removal of the rib and retropleural approach to the thoracolumbar spine. From this incision a retropleural insertion of the thoracoscope using an additional incision 2 ribs above the original incision can be performed if necessary. The vertebra and surrounding tissues are visualised by thoracoscope, all further necessary interventions as well as diaphragm splitting can be performed via the main approach. After trial operations on cadavers we performed a spondylodesis on 22 patients with fractures of the lower thoracic and upper lumbar spine using a semi-open technique.

With the above described incision we were able to expose all vertebrae from Th11 to L2 and to perform a splitting of the diaphragm. Two cases needed an intraoperative and one case a postoperative pleural drainage. The maximum blood loss was 200 ml, maximum operation time 180 min. No complications such as infections or malunion occurred during follow-up.

We conclude that the semi-open technique is combining the advantage of open and thoracoscopic surgery avoiding a collapse of the lung and reducing the number of pleural drainages. All levels of the thoracolumbar spine can be reached and a safe spondylodesis with minimal blood loss can be performed. However this technique is requiring a learning curve and should be preceded by animal or cadaver trial operations.

Purpose: The advent of lapaoscopic disectomy has made it possible to cure discal herniation with minimal trauma and no limitations on indications. We have adopted the technique described by J. Destandau since June 1998. The purpose of this work was to report our early results.

Material and methods: Forty patients were included in a period from June 1998 to August 2000. There were 24 men and 16 women, mean age 43 years (24–78). Eleven patients had an associated stenosis of the spinal canal. Accelerated rehabilitation was employed. Sitting and driving were allowed early.

Results: Mean follow-up was 13 months (2–27 months). Mean operative time was 63 minutes (30–150 min). Mean hospital stay was 3.92 days (2–10). There were 29 patients without stenosis of the lumbar canal. In this subgroup, outcome was excellent in 69%, good in 21% (six patients), fair in 3% (one patient), and poor in 7% (two patients). For the PROLO score, three patients were who were retreated were not included in the analysis. Outcome was excellent in 73% (19 patients), good in 12% (three patients), fair in 12% (three patients, and poor in 4% (one patient). In patients with lumbar canal stenosis, (eleven patients), three were reoperated for wider decompression; there was no haematoma. One patient was reoperated for deep infection. For the other patients the WADDELL score was excellent in five and good; in two the PROLO score was excellent in six and poor in one.

Discussion: The technique favoured a narrow approach. Shorter exposure preserved the anatomy, but for the three patients with an associated stenosis, reoperation was necessary for decompression. For the cases without complications, we noticed that recovery was very rapid, a finding which is exceptional with the conventional technique.

Conclusion: Our early experience with this technique has demonstrated that laparoscopic discectomy is feasible and safe. An associated stenosis is a limitation; we recommend systematic decompression in association with the discectomy.

Purpose: As proposed by Marnay, posterior fixation of the spine with self-stabilising forceps facilitates the operative procedure. These forceps enable lamolaminal, pediculolaminal, or pediculotransverse fixations. We developed a method for posterior fixation of the spine where a self-stabilising forceps links the lateral forceps hook to a medial hook allowing a bilateral hold on the segment for better fixation and correction. The aim of this work was to evaluate the contribution of the self-stabilising forceps compared with standard hooks during reduction movements.

Material and methods: Pull-out tests were conducted on five different holds using a supratransversal hook, a sublaminal hook, a pediculotransversal forceps, and a pediculolaminal forceps (Spine-Evolution), and a bipediculolaminal hook mounted on two vertebrae (Sofamor-Danek). The tests were performed on anatomic specimens. The test procedure was a reduction of a kyphosis of the upper part to the tested segment. Fourteen measurements were made for each implant.

Results: Pull-out force (N) was (mean, range): supratrans-versal hook (24, 8-40) < pediculotransvers forceps (154, 80-280) < supralaminal hook (360, 120–560) < pediculolam-inal forceps (491, 440–550) < bipediculolaminal forceps on two vertebrae (711, 400–800). The differences were significant.

Discussion: These results must be considered under the experimental conditions. Fixation with a supratransversal hook did not produce a reliable hold. The pediculotransversal forceps failed in one case due to fracture of a weak transversal mass. The supralaminal hook exhibited more consistent pull-out resistance. In most of the cases, pull-out occurred by fracture of the posterior arch. The bilateral self-stabilising forceps demonstrated the greatest pull-out resistance. During the five tests made with this forceps, the test was limited by the weakness of the osteosynthesis rods used so the maximal resistance to pull-out could not be measured (> 800 N).

Conclusion: The self-stabilising pediculolaminal forceps provides greater pull-out resistance than hooks alone. The self-stabilizing bipediculolaminal forceps allows a new surgical strategy for segmentary fixation with promising potential.