Intradiscal Pressure Measurements Above an Instrumented Fusion

Weinhoffer, Susan L.; Guyer, Richard D.; Herbert, Morley A.; Griffith, Steven L.

doi:10.1097/00007632-199503010-00004

Cited by 356 publications

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“…Adjacent segment degeneration is a common long-term sequela or complication of spinal fusion surgery. The exact aetiology is uncertain but alterations in facet loading, hypermobility, and increased intradiscal pressure at the segments adjacent to fusion mass is believed to play a key role [15,21,35,44,51,60]. Superior segment facet violation or laminectomy has recently shown in vitro to destabilize the adjacent level in transpedicular fixation [9].…”

Section: Discussionmentioning

confidence: 99%

Does Wallis implant reduce adjacent segment degeneration above lumbosacral instrumented fusion?

et al. 2009

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Delayed complications following lumbar spine fusion may occur amongst which is adjacent segment degeneration (ASD). Although interspinous implants have been successfully used in spinal stenosis to authors' knowledge such implants have not been previously used to reduce ASD in instrumented lumbar fusion. This prospective controlled study was designed to investigate if the implantation of an interspinous implant cephalad to short lumbar and lumbosacral instrumented fusion could eliminate the incidence of ASD and subsequently the related reoperation rate. Groups W and C enrolled initially each 25 consecutive selected patients. Group W included patients, who received the Wallis interspinous implant in the unfused vertebral segment cephalad to instrumentation and the group C selected age-, diagnosis-, level-, and instrumentationmatched to W group patients without interspinous implant (controls). The inclusion criterion for Wallis implantation was UCLA arthritic grade \II, while the exclusion criteria were previous lumbar surgery, severe osteoporosis or degeneration[UCLA grade II in the adjacent two segments cephalad to instrumentation. All patients suffered from symptomatic spinal stenosis and underwent decompression and 2-4 levels stabilization with rigid pedicle screw fixation and posterolateral fusion by a single surgeon. Lumbar lordosis, disc height (DH), segmental range of motion (ROM), and percent olisthesis in the adjacent two cephalad to instrumentation segments were measured preoperatively, and postoperatively until the final evaluation. VAS, SF-36, and Oswestry Disability Index (ODI) were used. One patient of group W developed pseudarthrosis: two patients of group C deep infection and one patient of group C ASD in the segment below instrumentation and were excluded from the final evaluation. Thus, 24 patients of group W and 21 in group C aged 65? 13 and 64? 11 years, respectively were included in the final analysis. The follow-up averaged 60 ± 6 months. The instrumented levels averaged 2.5 ? 1 vertebra for both groups. All 45 spines showed radiological fusion 8-12 months postoperatively. Lumbar lordosis did not change postoperatively. Postoperatively at the first cephalad adjacent segment: DH increased in the group W (P = 0.042); ROM significantly increased only in group C (ANOVA, P \ 0.02); olisthesis decreased both in flexion (P = 0.0024) and extension (P = 0.012) in group W. The degeneration or deterioration of already existed ASD in the two cephalad segments was shown in 1 (4.1%) and 6 (28.6%) spines in W and C groups, respectively. Physical function (SF-36) and ODI improved postoperatively (P \ 0.001), but in favour of the patients of group W (P \ 0.05) at the final evaluation. Symptomatic ASD required surgical intervention was in 3 (14%) patients of group C and none in group W. ASD remains a significant problem and accounts for a big portion of revision surgery following instrumented lumbar fusion. In this series, the Wallis interspinous implant changed the natural history of ASD and saved th...

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Section: Discussionmentioning

confidence: 99%

Does Wallis implant reduce adjacent segment degeneration above lumbosacral instrumented fusion?

et al. 2009

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“…It has been postulated that cervical fusion alters the biomechanical conditions at adjacent segments resulting in increased loading, intradiscal pressure and shear, and excessive movement which in turn might lead to accelerated ASD [16,17,50,61,79,96]. Long-term follow-up studies in ACDFP established that 10-25% of patients develop ASD at a mean of 10 years after the index surgery with some requiring reoperation [50].…”

Section: Adjacent-segment Degenerationmentioning

confidence: 99%

Mid- to long-term outcome of instrumented anterior cervical fusion for subaxial injuries

et al. 2009

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The management of patients with subaxial cervical injuries lacks consensus, particularly in regard to the decision which surgical approach or combination of approaches to use and which approach yields the best clinical outcome in the distinct injury. The trauma literature is replete with reports of surgical techniques, complications and gross outcome assessment in heterogeneous samples. However, data on functional and clinical outcome using validated outcome measures are scanty. Therefore, the authors performed a study on plated anterior cervical decompression and fusion for unstable subaxial injuries with focus on clinical outcome. For the purpose of a strongly homogenous subgroup of patients with subaxial injuries without spinal cord injuries, robust criteria were applied that were fulfilled by 28 patients out of an original series of 131 subaxial injuries. Twenty-six patients subjected to 1-and 2-level fusions without having spinal cord injury could be surveyed after a mean of 5.5 years (range 16-128 months). The cervical spine injury severity score averaged 9.6. Cross-sectional outcome assessment included validated outcome measures (Neck pain disability index, Cervical Spine Outcome Questionnaire, SF-36), the investigation of construct failure and successful surgical outcome were defined by strict criteria, the reconstruction and maintenance of local and total cervical lordosis, adjacent-segment degeneration and intervertebral motion, and the fusion-rate using an interobserver assessment. Selfrated clinical outcome was excellent or good in 81% of patients and moderate or poor in 19% that corresponded to the results of the validated outcome measures. Results of the NPDI averaged 12.4 ± 12.7% (0-40). With the SF-36 mean physical and mental component summary scores were 47.0 ± 9.8 (18.2-59.3) and 52.2 ± 12.4 (14.6-75.3), respectively. Using merely non-constrained plates, construct failure was observed in 31% of cases and loss of local lordosis, expressed as a mean injury angle of 14°, postoperative angle of -5.5°and follow-up angle of -1°, was significant. However, total cervical lordosis was within the limits of normalcy (-24.3°± 13.3) and fusion-rate was 88.5%. The progression of adjacent-level degeneration was shown to be significantly influenced by a decreased plate-to-disc-distance. Adjacent-level intervertebral motion was not altered due to the adjacent fusion, but reduced in Electronic supplementary material The online version of this article

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“…Biomechanical studies of lumbar spine demonstrate increased facet load, segmental motion and intradiscal pressure at the segment adjacent to fusion where the fusion was performed and these changes are associated with ASD [1][2][3][4]. In the cervical spine, biomechanical characteristics are different from those of lumbar spine.…”

Section: Introductionmentioning

confidence: 99%

What are the associative factors of adjacent segment degeneration after anterior cervical spine surgery? Comparative study between anterior cervical fusion and arthroplasty with 5-year follow-up MRI and CT

et al. 2012

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Purpose It is well known that arthrodesis is associated with adjacent segment degeneration (ASD). However, previous studies were performed with simple radiography or CT. MRI is most sensitive in assessing the degenerative change of a disc, and this is the first study about ASD by radiography, CT and MRI. We sought to factors related to ASD at cervical spine by an MRI and CT, after anterior cervical spine surgery. Materials and methods This is a retrospective crosssectional study of cervical disc herniation. Patients of cervical disc herniation with only radiculopathy were treated with either arthroplasty (22 patients) or ACDF with cage alone (21 patients). These patients were required to undergo MRI, CT and radiography preoperatively, as well as radiography follow-up for 3 months and 1 year, and we conducted a cross-sectional study by MRI, CT and radiography including clinical evaluations 5 years after. Clinical outcomes were assessed using VAS and NDI. The fusion rate and ASD rate, and radiologic parameters (cervical lordosis, operated segmental height, C2-7 ROM, operated segmental ROM, upper segmental ROM and lower segmental ROM) were measured. Results The study groups were demographically similar, and substantial improvements in VAS (for arm) and NDI (for neck) scores were noted, and there were no significant differences between groups. Fusion rates were 95.2 % in the fusion group and 4.5 % in the arthroplasty group. ASD rates of the fusion and arthroplasty groups were 42.9 and 50 %, respectively. Among the radiologic parameters, operated segmental height and operated segmental ROM significantly decreased, while the upper segmental ROM significantly increased in the fusion group. In a comparative study between patients with ASD and without ASD, the clinical results were found to be similar, although preexisting ASD and other segment degeneration were significantly higher in the ASD group. C2-7 ROM was significantly decreased in ASD group, and other radiologic parameters have no significant differences between groups. Conclusion The ASD rate of 46.5 % after ACDF or arthroplasty, and arthroplasty did not significantly lower the rate of ASD. ASD occurred in patients who had preexisting ASD and in patients who also had other segment degeneration. ASD may be associated with a natural history of cervical spondylosis rather than arthrodesis.

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Intradiscal Pressure Measurements Above an Instrumented Fusion

Cited by 356 publications

References 0 publications

Does Wallis implant reduce adjacent segment degeneration above lumbosacral instrumented fusion?

Does Wallis implant reduce adjacent segment degeneration above lumbosacral instrumented fusion?

Mid- to long-term outcome of instrumented anterior cervical fusion for subaxial injuries

What are the associative factors of adjacent segment degeneration after anterior cervical spine surgery? Comparative study between anterior cervical fusion and arthroplasty with 5-year follow-up MRI and CT

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