Here is a study that Professionally Integrated members should write a letter and send to the surgeons in your area. The authors took cervical spines and evaluated the intradiscal pressure above and below a fusion based on sagittal alignment. I have posted many other discussions on this site on why a kyphosis is bad and how it can cause increased degeneration. Here is a study where we can help patients after a fusion surgery with corrective care for better outcomes. Here is what the authors discuss:
“There is level III evidence that ASP is more frequent in patients with kyphotic fusion”
“The IDP increase at the adjacent C6-C7 segment below the fusion became greater with increasing C2-C7 tilt angle”. Increasing the angle, increases the IDP leading to disc pathology.
“We believe that the increased mechanical burden on adjacent segments is only one piece of the complex puzzle of ASP after cervical fusion surgery. The ‘‘health’’ of the adjacent segment will influence its ability to successfully adapt to the increased loading demands.” I feel this is important for outcomes, if the patients discs are even slightly degenerated before surgery, the outcomes may not be good.
CONCLUSION Cervical sagittal imbalance arising from regional and/or global spinal sagittal malalignment may play a role in exacerbating adjacent segment pathomechanics after multilevel fusion and should be considered during cervical fusion surgical planning.
The study investigated the effects of in situ two level cervical fusion on adjacent segment biomechanics in the presence of cervical sagittal imbalance.
Human cervical spine specimens were tested in a previously validated laboratory model that allowed measurement of spinal response to prescribed imbalance.
Effects of fusion on segmental angular alignments and intradiscal pressures in the C3-C4 and C6-C7 discs, above and below in situ C4-C6 fusion, were evaluated at different magnitudes of C2-C7 tilt angle (or C2-C7 SVA).
When compared with the pre-fusion state, in situ fusion across C4-C6 required increased flexion angulation and resulted in increased IDP at the C6-C7 disc below the fusion in order to accommodate the same increase in C2-C7 tilt angle.
The adjacent segment mechanical burden due to fusion became greater with increasing C2-C7 tilt angle or SVA. Cervical sagittal imbalance may play a role in exacerbating adjacent segment pathomechanics after multilevel fusion and should be considered during surgical planning.
Here is the paper: Remember members, call with any questions. Is Cervical Sagittal Imbalance a Risk Factor for Adjacent Segment Pathomechanics After Multilevel Fusion? Avinash G. Patwardhan, PhD,,y Saeed Khayatzadeh, PhD,,z Ngoc-Lam Nguyen, MD,y Robert M. Havey, MS,,y Leonard I. Voronov, MD, PhD,,y Muturi G. Muriuki, PhD, Gerard Carandang, MS, Zachary A. Smith, MD,§ William Sears, MD,jj Laurie M. Lomasney, MD,y and Alexander J. Ghanayem, MD,y Study
SPINE Volume 41, Number 10, pp E580–E588 2016