Othmar Schwarzenbach | PubMed Health

PubMed2006

Venous injury in lumbar anterior spine surgery.

UNLABELLED: To assess the clinical and angiological outcome of venous injury in lumbar anterior spine surgery. DESIGN: Follow-up study. METHODS: During a seven-year time span 77 consecutive patients underwent lumbar anterior spine surgery. Of these patients three patients suffered two minor and two major vein injuries. In two cases this was a common iliac vein injury. The other two injuries were at the level of the junction of the iliac veins with the inferior vena cava. The injuries were repaired by direct suture and the patients were followed-up by an independent angiologist. RESULTS: The follow-up, done clinically and with duplex sonography, plethysmography and ankle pressures showed no sequelae from the venous injuries. CONCLUSIONS: Venous injuries following anterior spine surgery are rare and may have a good recovery. Preoperative informed consent is recommended.

Adult↗

PubMed2005

Posterior dynamic stabilization systems: DYNESYS.

Posterior dynamic stabilization systems have to neutralize injurious forces and restore painless function of the spine segments and protect the adjacent segments. Because degenerative disc disease has many clinical manifestations, pedicular screw systems and interspinous implants have their indications. A dynamic stabilization device has to provide stability throughout its lifetime, unless it activates or allows reparative processes with a reversal of the degenerative changes. Anchorage to the bone is crucial, at least for pedicular systems. This is a great demand on spinal implants and assumes rest and motion going together. Our experience with DYNESYS has shown that this method has limitations in elderly patients with osteoporotic bone or in patients with a severe segmental macro-instability combined with degenerative olisthesis and advanced disc degeneration. Such cases have an increased risk of failure. Only future randomized evaluations will be able to address the potential reduction of accelerated adjacent segment degeneration. The few posterior dynamic stabilization systems that have had clinical applications so far have produced clinical outcomes comparable with fusion. No severe adverse events caused by these implants have been reported. Long-term follow-up data and controlled prospective randomized studies are not available for most of the cited implants but are essential to prove the safety, efficacy, appropriateness, and economic viability of these methods.

Adult↗

PubMed2002

The dynamic neutralization system for the spine: a multi-center study of a novel non-fusion system.

Various forms of lumbar instability require a surgical stabilization. As an alternative to fusion, a mobile, dynamic stabilization restricting segmental motion would be advantageous in various indications, allowing greater physiological function and reducing the inherent disadvantages of rigid instrumentation and fusion. The dynamic neutralization system for the spine (Dynesys) is a pedicle screw system for mobile stabilization, consisting of titanium alloy screws connected by an elastic synthetic compound, controlling motion in any plane (non-fusion system). This prospective, multi-center study evaluated the safety and efficacy of Dynesys in the treatment of lumbar instability conditions, evaluating pre- and post-operative pain, function, and radiological data on a consecutive series of 83 patients. Indications consisted of unstable segmental conditions, mainly combined with spinal stenosis (60.2%) and with degenerative discopathy (24.1%), in some cases with disc herniation (8.4%), and with revision surgery (6.0%). Thirty-nine patients additionally had degenerative spondylolisthesis, and 30 patients had undergone previous lumbar surgery. In 56 patients instrumentation was combined with direct decompression. The mean age at operation was 58.2 (range 26.8-85.3) years; the mean follow-up time was 38.1 months (range 11.2-79.1 months). There were nine complications unrelated to the implant, and one due to a screw malplacement. Four of them required an early surgical reintervention. Additional lumbar surgery in the follow-up period included: implant removal and conversion into spinal fusion with rigid instrumentation for persisting pain in three cases, laminectomy of an index segment in one case and screw removal due to loosening in one case. In seven cases, radiological signs of screw loosening were observed. In seven cases, adjacent segment degeneration necessitated further surgery. Mean pain and function scores improved significantly from baseline to follow-up, as follows: back pain scale from 7.4 to 3.1, leg pain scale from 6.9 to 2.4, and Oswestry Disability Index from 55.4% to 22.9%. These study results compare well with those obtained by conventional procedures; in addition to which, mobile stabilization is less invasive than fusion. Long-term screw fixation is dependent on correct screw dimension and proper screw positioning. The natural course of polysegmental disease in some cases necessitates further surgery as the disease progresses. Dynamic neutralization proved to be a safe and effective alternative in the treatment of unstable lumbar conditions.

Adult↗