Comparisons of Lordotic Cervical Spine Curvatures to a Theoretical Ideal Model of the Static Sagittal Cervical Spine

Harrison, Donald D.; Janik, Tadeusz J.; Troyanovich, Stephan J.; Holland, Burt

doi:10.1097/00007632-199603150-00002

Cited by 164 publications

(115 citation statements)

References 18 publications

Supporting

Mentioning

105

Contrasting

Unclassified

Order By: Relevance

“…Our study protocol determined a minimum follow-up of 6 months on basis of prior experience demonstrating that significant changes in construct geometry occur within about 3 months after surgery [23,28,36,49,111,126]. We evaluated geometrical changes in sagittal plane and cervical lordosis with the widespread technique of Harrison et al [38,44,111,113,123], using the angle formed between the tangential lines on the posterior edge of the vertebral bodies C2-7. In all 26 patients using the radiographs or digital imaging enhanced techniques relevant bony landmarks and fused levels were discernible, at least to one half of the posterior vertebral body wall at T1.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

4- and 5-level anterior fusions of the cervical spine: review of literature and clinical results

et al. 2007

View full text Add to dashboard Cite

In the future, there will be an increased number of cervical revision surgeries, including 4-and more-levels. But, there is a paucity of literature concerning the geometrical and clinical outcome in these challenging reconstructions. To contribute to current knowledge, we want to share our experience with 4-and 5-level anterior cervical fusions in 26 cases in sight of a critical review of literature. At index procedure, almost 50% of our patients had previous cervical surgeries performed. Besides failed prior surgeries, indications included degenerative multilevel instability and spondylotic myelopathy with cervical kyphosis. An average of 4.1 levels was instrumented and fused using constrained (26.9%) and non-constrained (73.1%) screw-plate systems. At all, four patients had 3-level corpectomies, and three had additional posterior stabilization and fusion. Mean age of patients at index procedure was 54 years with a mean follow-up intervall of 30.9 months. Preoperative lordosis C2-7 was 6.5°in average, which measured a mean of 15.6°at last follow-up. Postoperative lordosis at fusion block was 14.4°in average, and 13.6°at last follow-up. In 34.6% of patients some kind of postoperative change in construct geometry was observed, but without any catastrophic construct failure. There were two delayed unions, but finally union rate was 100% without any need for the Halo device. Eleven patients (42.3%) showed an excellent outcome, twelve good (46.2%), one fair (3.8%), and two poor (7.7%). The study demonstrated that anterior-only instrumentations following segmental decompressions or use of the hybrid technique with discontinuous corpectomies can avoid the need for posterior supplemental surgery in 4-and 5-level surgeries. However, also the review of literature shows that decreased construct rigidity following more than 2-level corpectomies can demand 360°instrumentation and fusion. Concerning construct rigidity and radiolographic course, constrained plates did better than non-constrained ones. The discussion of our results are accompanied by a detailed review of literature, shedding light on the biomechanical challenges in multilevel cervical procedures and suggests conclusions.

show abstract

Section: Methodsmentioning

confidence: 99%

“…Lordosis at fusion block C x -C x+4/x+5 was measured at aforementioned intervals with the technique of Harrison et al [44].…”

Section: Methodsmentioning

confidence: 99%

4- and 5-level anterior fusions of the cervical spine: review of literature and clinical results

et al. 2007

View full text Add to dashboard Cite

show abstract

“…At follow-up, the SRA was assessed for all levels C2-T1 using the Harrison method [45]. In neutral position, the segmental rotation angles are expressed as the SRA, and the segmental range of motion (ROM) calculated from the SRA on flexion-extension films is expressed as the rSRA for each level.…”

Section: Analysis Of Absolute and Segmental Rotation Anglementioning

confidence: 99%

“…The incidence of construct failure was significantly higher in surgeries at the C6-7 level (P = 0.01) as compared to the more cephalad levels and in patients that postoperatively showed lower correction of the injury kyphosis and translation (P = 0.01; P = 0.02). Taking into account the segmental lordosis at fusion level compared to that of a physiological standard [45], 11 patients (42.3%) had a successful surgical outcome. The incidence of having a successful surgical outcome was significantly increased in patients that had AO Type A or B injuries as compared to Type C injuries (P = 0.03).…”

Section: Construct Geometrymentioning

confidence: 99%

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

et al. 2009

View full text Add to dashboard Cite

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

show abstract

“…

…”

mentioning

confidence: 99%

Answer to the letter to the editor of Dr. D.E. Harrison et al. regarding “The association between cervical spine curvature and neck pain” (D. Grob et al., Eur Spine J, published online Nov 18, 2006)

2007

View full text Add to dashboard Cite

We thank Dr. Harrison for his interest in our work and for taking time to share his thoughts concerning the discrepancies between the findings of our respective studies.We apologize for wrongly characterizing one of his papers/inadvertently mixing up two of the papers [5,6] in our Table 4 [3]. This was indeed an error on our behalf, and occurred as a result of the later insertion into the manuscript (which, incidentally, started out as an MD thesis written in German) of the wrong Harrison et al. reference; we hope that Harrison et al. will be prepared to interpret this as a compliment, in relation to the huge amount of work they have published in this field! To say that we suggested their results were ''questionable due to improper study design'' is somewhat exaggerated paraphrasing of the statements made in our discussion. We were merely looking for differences between the studies that might have accounted for the discrepant results. The notion that there may have been some methodological issues at stake was prompted by the observation that the mean cervical lordosis in their asymptomatic population was larger than the values previously reported in the literature for asymptomatics. We simply stated that Harrison et al. did not report whether identical radiographic methods (and in particular standardized subject positioning) were used in the two retrospective studies carried out 10 years apart; we do not say that comparable methodology was not used, only that it wasn't mentioned in their papers (and this was later conceded by the authors themselves in their letter to the editor:''although our x-ray procedure was not detailed in our more recent paper…''), and was hence to be considered a possible explanation for the findings. Given the long time that elapsed between their two retrospective studies and the known advances in modern imaging techniques, we considered that this was a potentially plausible explanation, in the absence of any information suggesting the contrary. This was intended to constitute a normal process of scientific deduction, not a pointed criticism of their work.We already discussed in our original paper [3] the potential difference between the two study groups arising from Harrison et al.'s exclusion of individuals with segmental/total kyphosis [7], and we confirmed that applying the same criterion to our own subject group did not alter our findings. The other exclusion criteria used by Harrison et al. [7] but not by ourselves [3], i.e., moderate-severe disc disease, and any significant forward head posture, may indeed have contributed to their higher values for the cervical lordosis in their NO PAIN group. However, one would then have to argue that, using these exclusion criteria, one no longer has a valid representation of the asymptomatic population. In other words, it may explain the differences between the cervical lordosis in two select groups of people, but it doesn't answer the question as to whether lordosis and symptoms per se are related. This was the question we sought to answer.Th...

show abstract

Comparisons of Lordotic Cervical Spine Curvatures to a Theoretical Ideal Model of the Static Sagittal Cervical Spine

Cited by 164 publications

References 18 publications

4- and 5-level anterior fusions of the cervical spine: review of literature and clinical results

4- and 5-level anterior fusions of the cervical spine: review of literature and clinical results

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

Answer to the letter to the editor of Dr. D.E. Harrison et al. regarding “The association between cervical spine curvature and neck pain” (D. Grob et al., Eur Spine J, published online Nov 18, 2006)

Contact Info

Product

Resources

About