Long-term Outcome After Monosegmental L4/5 Stabilization for Degenerative Spondylolisthesis With the Dynesys Device

Abstract

Study Design: Retrospective analysis of prospectively collected clinical data.Objective: To assess the long-term outcome of patients with monosegmental L4/5 degenerative spondylolisthesis treated with the dynamic Dynesys device. Summary of Background Data:The Dynesys system has been used as a semirigid, lumbar dorsal pedicular stabilization device since 1994. Good short-term results have been reported, but little is known about the long-term outcome after treatment for degenerative spondylolisthesis at the L4/5 level.Methods: A total of 39 consecutive patients with symptomatic degenerative lumbar spondylolisthesis at the L4/5 level were treated with bilateral decompression and Dynesys instrumentation. At a mean follow-up of 7.2 years (range, 5.0-11.2 y), they underwent clinical and radiographic evaluation and quality of life assessment.Results: At final follow-up, back pain improved in 89% and leg pain improved in 86% of patients compared with preoperative status. Eighty-three percent of patients reported global subjective improvement. Ninety-two percent would undergo the surgery again. Eight patients (21%) required further surgery because of symptomatic adjacent segment disease (6 cases), lateonset infection (1 case), and screw breakage (1 case). In 9 cases, radiologic progression of spondylolisthesis at the operated segment was found. Seventy-four percent of operated segments showed limited flexion-extension range of <4 degrees. Adjacent segment pathology, although without clinical correlation, was diagnosed at the L5/S1 (17.9%) and L3/4 (28.2%) segments. In 4 cases, asymptomatic screw loosening was observed.Conclusions: Monosegmental Dynesys instrumentation of degenerative spondylolisthesis at L4/5 shows good long-term results. The rate of secondary surgeries is comparable to other dorsal instrumentation devices. Residual range of motion in the stabilized segment is reduced, and the rate of radiologic and symptomatic adjacent segment degeneration is low. Patient satisfaction is high. Dynesys stabilization of symptomatic L4/5 degenerative spondylolisthesis is a possible alternative to other stabilization devices.

A new device used in the restoration of kinematics after total facet arthroplasty

“…As with our cohort, residual range of motion is reduced, as well as the need for secondary surgery 24. Yet with all favorable results, there are also reports that show inferior long-term functional and clinical outcomes compared to fusion, except for older patients, who appear to be more satisfied 25…”

Comparison of pedicle screw–based dynamic stabilization and fusion surgery in the treatment of radiographic adjacent-segment degeneration: a retrospective analysis of single L5–S1 degenerative spondylosis covering 4 years

“…3,12 The notion that spinal fusion changes the biomechanics of adjacent levels has played a large role in the development of motionpreserving techniques in lumbar surgery. Clinical studies have shown that PDS offers satisfactory short-term clinical outcomes and suggested that PDS is a possible alternative to PLIF, 9,19 but little research has found that it helps to prevent ASD. In a 4-year follow-up study, Schaeren et al 27 found that degeneration in adjacent motion segments progresses after Dynesys dynamic stabilization.…”

Dynamic stabilization for L4–5 spondylolisthesis: comparison with minimally invasive transforaminal lumbar interbody fusion with more than 2 years of follow-up

“…During a mean followup of 7.2 years, they dem onstrated that over 80% of patients' back and leg pain improved significantly following surgery. 10 Payer et al re ported another retrospective study, which included 30 pa tients with singlelevel degenerative spondylolisthesis and spinal stenosis who were followed up for 2 years. Payer and colleagues demonstrated improved functional out comes including VAS scores of leg and back pain, which improved significantly.…”

“…Dynamic stabilization methods include interspinous devices and pedicle screw-based stabilization systems. The Dynesys dynamic stabilization (DDS; Zimmer Bio met) system is the subject of many published reports on its application for the management of lumbar degenerative disc disease, 6,13,31,32 spondylolisthesis, 7,8,10,20,22 and even de generative scoliosis. 3,4,15 However, the application of these dynamic constructs for spondylolisthesis and its clinical outcomes remain unclear.…”