Abstract
Background: Non-rigid fixation clearly appears to be a useful technique in the management of degenerative intervertebral lumbar disc disease. A mobile, dynamic stabilization restricting segmental motion is possible to be advantageous in various indications, allowing greater physiological function and reducing the inherent disadvantages of rigid instrumentation and fusion.
Aim: This study is a prospective analysis of the early results of second generation Wallis implant for degenerative disc disease.
Methods and Materials: Twenty-five patients with leg and back pain that was not responsive to conservative treatment underwent discectomy and implantation of second generation device. There were 22 one-level and 3 two-level cases. The preoperative radiological work-up included conventional X-rays, computed tomography and magnetic resonance imaging (MRI). All patients underwent neurological examination, assessment of pain on a visual analog scale, and a functional evaluation using the Revised Oswestry disability index before surgery, 3 months after surgery and at follow- up.
Results: A total of 25 patients (13 men, 12 women) with a mean age of 51.9 years (range, 34 to 69 years) were evaluated with a mean follow-up of 1.4 year after the intervention. Mean pain and function scores improved significantly from baseline to follow up as follows: – back pain scale from 7.2 to 2.9, leg pain scale from 6.8 to 2.5 and Oswestry Disability Index from 59.1% to 22.6%. No cases of infection or worsening of neurological deficit occurred. One patient had revision surgery for persistent pain as a result of granulation tissue underneath the implant. No mechanical failure of the implants or loosening was observed and the process retained motion.
Conclusion: Clinical results are satisfactory and compare well with those obtained by conventional procedures in addition to which mobile stabilisation are less invasive then fusion. Wallis neutralisation proves to be a safe and effective in the treatment of unstable lumbar condition.
Correspondence should be addressed to Mr J. O’Dowd, Honorary Secretary at SBPR c/o BOA, Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London, WC2A 3PE.
