Treatment of lumbar spinal stenosis with a total posterior arthroplasty prosthesis: implant description, surgical technique, and a prospective report on 29 patients

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Total disc replacement is an alternative to lumbar fusion, but patients with spinal stenosis, spondylolisthesis, and facet arthropathy are often excluded from this procedure because increased adjacent-segment motion can exacerbate dorsal spondylotic changes. In such cases of degenerative spondylolisthesis with stenosis, decompression and fusion remain the gold standard of treatment. To avoid attendant loss of motion at the treated segment, the TOPS system is a novel total posterior arthroplasty prosthesis that allows for an alternative dynamic, multiaxial, three-column stabilization and motion preservation. The purpose of this study is to report preliminary surgical data and clinical outcomes in patients treated with the TOPS lumbar total posterior arthroplasty system.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Twenty-nine patients were enrolled in a nonrandomized, multicenter, prospective pilot study outside the US. All patients had spinal stenosis and/or spondylolisthesis at L4–5 due to facet arthropathy. Radiographs and scores on outcome measures including the visual analog scale (VAS) for pain, Oswestry Disability Index (ODI), Short Form-36, and Zurich Claudication Questionnaire were prospectively recorded before surgery and at 6-week, 3-month, 6-month, and 1-year intervals after surgery. Prior to instrumentation, a bilateral total facetectomy and laminectomy at L4–5 or L3–4 was performed via a standard midline posterior approach. After decompression, the TOPS screws were inserted into four pedicles to achieve maximal purchase with triangulating bicortical trajectories. An appropriately sized TOPS arthroplasty implant was then applied.</jats:p> <jats:p>The mean surgical time was 3.1 hours, and patients' clinical status improved significantly following treatment with the TOPS device. The mean ODI score decreased compared with baseline by 41% at 1 year, and the 100-mm VAS score declined by 76 mm over the same time period. Radiographic analysis showed that lumbar motion was maintained, disc height was preserved, and no evidence of screw loosening was found. No device malfunctions or migrations and no device-related adverse events were reported during the study.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The TOPS total posterior arthroplasty system represents a novel, dynamic, posterior arthroplasty device that provides multiaxial stability in flexion, extension, rotation, and lateral bending after total facetectomy and neural decompression. The surgical data indicate that it can be safely applied via a traditional approach with low surgical morbidity and excellent 1-year functional and radiographic outcomes in patients with degenerative spondylolisthesis accompanied by stenosis and back pain.</jats:p></jats:sec>

Simple facet joint repair with dynamic pedicular system: Technical note and case series

“…As well, the center of rotation for the segment shifts away from where it exists when the facet joints are intact. [ 5 ]…”

“…Considering the functional importance of facet joints, when removal of a facet is required, it is important to apply an implant that will simulate the role of the facet joint. The literature describes numerous pioneered systems[ 5 6 7 8 ] for total facet replacement, including TOPS, DSS, TFAS, and Stabilimax NZ; but none of these has yielded satisfactory clinical results worldwide. Moreover, surgical application of TOPS is reported to be difficult, and DSS and Stabilimax NZ are originally complex dynamic systems.…”

Is Degenerative Spondylolisthesis a Contraindication for Total Disc Replacement? Kineflex Lumbar Disc Replacement in 7 Patients With 24-Month Follow-up

“…Recently McAfee et al reported clinical improvement with a motionpreserving facet replacement system (TOPS). 28 …”

Total Posterior Spinal Arthroplasty Systems for Dynamic Stability

“…The TOPS System is an active singlelevel prosthesis wedged between two pedicle screw-fixated titanium plates. It allows for side bending, axial rotation, and flexion/extension range of motion while limiting sagittal translation [13]. It is currently indicated for LSS, spondylolisthesis, and facet arthrosis and has been increasingly proven safe and effective for these conditions [13][14][15].…”

“…It allows for side bending, axial rotation, and flexion/extension range of motion while limiting sagittal translation [13]. It is currently indicated for LSS, spondylolisthesis, and facet arthrosis and has been increasingly proven safe and effective for these conditions [13][14][15]. Despite this encouraging evidence, it continues to be an experimental device and, thus, further high-quality studies are warranted.…”