Cervical Spondylotic Myelopathy Surgical Trial
Phase: NA
Conditions: Cervical Spondylosis With Myelopathy
Sponsor: Lahey Clinic

 
 
 
 
 
 
 
 
 
PROTOCOL FOR RESEARCH INVOLVING HUMAN RESEARCH 
Cervical Spondylotic Myelopathy Surgical Trial 
NCT02076113 
July 1, 2020 

 
 
 
 
 
 
 
 
 
PROTOCOL FOR RESEARCH INVOLVING HUMAN SUBJECTS 
 
TITLE OF PROJECT: Cervical Spondylotic Myelopathy Surgical Trial (CSM-S Trial)
 
VERSION:  6.0,  DATE:  7/1/2020 
 
Study Sponsor: Patient-Centered Outcomes Research Institute (PCORI) 
 
 
Name 
Signature 
Email Address 
Principal Investigator:  
Zoher Ghogawala MD 
 
Zoher.ghogawala@lahey.org 
Other Investigator(s):  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Correspondent 
 
 
 
 
 
 
Mailing Address:  
41 Mall Road 
 
 
 
               Phone: 781-744-8984 
 
 
 
Burlington, MA 01805 
 
                             Fax: 781-744-5778 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
II. DESCRIPTION OF STUDY 
 
A. 
Purpose 
 
1a. To determine if ventral surgery is associated with superior SF-36 PCS outcome at one 
year follow-up compared to dorsal (fusion or laminoplasty) surgery. 
 
1b. To determine if, compared to pre-operative baseline status, both ventral and dorsal 
surgery for CSM improve symptoms of spinal cord dysfunction using mJOA. 
 
2.  To determine if, from a patient perspective, health resource utilization (out-of-pocket 
expenses and loss of productivity) for ventral surgery, dorsal fusion, and laminoplasty 
surgery are different. 
 
3.  To determine if cervical sagittal balance post-operatively is a significant predictor of 
SF-36 PCS outcome. 
 
B. 
Background 
 
Surgical decompression for CSM can improve its disabling symptoms, but surgical 
complications are common and many of these complications affect patients’ overall 
health-related quality of life.  The optimal surgical treatment, therefore, remains 
controversial, with disagreement between three main approaches:  ventral decompression 
and fusion, dorsal decompression and fusion, or dorsal laminoplasty.  This study aims to 
test the hypothesis that ventral surgery is associated with superior SF-36 PCS outcome at 
one year follow-up compared to dorsal approaches and that both ventral and dorsal 
surgery improve symptoms of spinal cord dysfunction using the mJOA score.  A 
secondary hypothesis is that health resource utilization for ventral surgery, dorsal fusion, 
and laminoplasty surgery are different.  A third hypothesis is that cervical sagittal balance 
post-operatively is a significant predictor of SF-36 PCS outcome. 
 
C. 
Specific Location of Study 
 
This is a multi-center trial.  Subjects will be entered into the study from 10 separate 
centers.  
  
D. 
Probable Duration of Project 
 
Subjects will be recruited into the study over an 18 month period.  All subjects will be 
followed for 5 years with clinical questionnaires. 
 
 
 
 
 
 

E. 
Research Plan  
 
1) Prospective, randomized multicenter trial.  Approximately 159 randomized and 91 
non-randomized patients would be recruited over 18 months with follow-up through 5 
years. 
 
2) Subjects (aged 45-80 years) with CSM (2 or more levels of spinal cord compression 
from C3 to C7) with 2 or more of the following symptoms/signs, clumsy hands, gait 
disturbance, hyperreflexia, up going toes, bladder dysfunction, or ankle clonus, will be 
treated with either ventral decompression/fusion, dorsal decompression with fusion, or 
dorsal laminoplasty.  (Patients <45 years of age do not generally suffer from degenerative 
arthritis, which is why the lowest age of inclusion is 45). 
 
3) Subjects with C2-C7 kyphosis > 5˚ (measured in standing neutral cervical spine 
radiograph), a segmental kyphotic deformity defined as 3 or more disc-osteophytes that 
extend dorsal to a C2-C7 dorsal-caudal line measured on cervical spine CT, structurally 
significant ossification of the posterior longitudinal ligament (OPLL), previous cervical 
spine surgery, or significant active health-related comorbidity (Anesthesia Class IV or 
higher) would be excluded from the study. 
 
4)  Each subject will be treated with either a Front Decompression/Fusion or Back of the 
Neck Decompression with fusion or Laminoplasty as part of standard clinical care. 
Decompression of the spinal canal to a diameter of at least 13 mm with restoration of 
cerebrospinal fluid flow around the spinal cord will be the goal, regardless of the 
approach. Surgical techniques have been standardized.  Back of the neck decompression 
with fusion and laminoplasty are equivalent and preliminary evidence suggests that the 
outcomes are similar using the SF-36 PCS, which is the same questionnaire being used in 
this study (see table in Power Analysis section below). 
 
5) Functional outcomes will be determined using well-known quantitative scales (SF-36, 
Oswestry Neck, mJOA, and EuroQol-5D).  These instruments will be administered pre-
op, 3 months, 6 months, and at 1 year. Additionally, functional outcomes instruments 
(SF-36, Oswestry Neck, and EuroQol-5D) will be collected annually at years 2,3,4 and 5.  
 
6) Two independent neuroradiologists will review post-operative imaging at 3 months, 
and 1 year.  Post-operative cervical spine MRI will be performed at 3 months  to 
document satisfactory spinal cord decompression. Cervical spine flexion-extension 
radiographs will be obtained pre-operatively on all patients and at one year after surgery 
to assess cervical fusion and/ or radiographic complications. Standing cervical-thoracic-
lumbar-sacral films will be obtained on all patients pre-operatively and at one year 
postoperatively (post-operatively in the randomized group only) to assess cervical as well 
as overall sagittal balance.  A cervical spine CT will be obtained on patients at 1 year 
who have an NDI score > 30 or whose plain films suggest instability. 
 

7) A study coordinator will collect data at 30 days and at 1 year to document any 
complications or re-operations. Additionally, the study coordinator will assess whether 
the patient is having any swallowing complications following surgery. 
 
8)  Health resource utilization information (including out-of-pocket expenses) will be 
obtained using patient diaries along with copies of all medical bills and receipts at 1 
month, 3 months, 6 months, and 12 months post-operatively for all of the patients.  
Participants also will be asked to keep track of days missed from work and days unable to 
perform usual activities, in addition to days missed from work for medical treatments or 
evaluations. 
 
 
 
F. 
Data and Safety Monitoring Plan 
 
1) All serious unexpected adverse events (e.g. death within 30 days of operation) will be 
reported to the IRB within 24 hours.  Any appropriate funding agencies or regulatory 
agencies would be notified as well.   
2) Any serious anticipated adverse event (e.g. wound infection, pulmonary embolus) 
will be reported to the IRB whenever their magnitude or frequency exceeds 
expectations. 
3) All other adverse events (including loss of privacy, significant economic harm) will 
be reported to the IRB on an annual basis or at the time that re-approval is sought.  
Any adverse event judged unlikely or unrelated to the study will also be included in 
an annual report for the IRB. 
          
G. 
Statistical Considerations 
 
a. Specific data variables being collected for the study.   
 
The data collection sheets will be submitted along with this protocol.  There will be 
several data sheets as follows:   
 
1) Screening/Baseline, 1 Month, 3 Months, 6 Months, and 1 Year Visit Checklist  
2) Informed Consent Process  
3) Inclusion/Exclusion Criteria  
4) Baseline Demographics  
5) Spine surgeon's data sheet  
6) 30-day and 1 Year morbidity data sheet 
7) 1 Month, 3 Months, 6 Months, 1 Year Return to Work Status 
8)  3 Month Swallowing Evaluation 
9) Initial Hospital Admission Data Sheet 
10) 3 Months and 1 Year Radiology 
11) End of Study 
12) Adverse Event Form 
13) Serious Adverse Event Report Form 

14) Serious Adverse Event Follow-up Report Form 
15) SF-36 questionnaires (pre-op, 3 months, 6 months, 1, 2, 3, 4, and 5 years),  
16) Neck Disability Index questionnaires (pre-op, 3 months, 6 months, 1, 2, 3, 4, and 5 
years) 
17) mJOA, (pre-op, 3 months, 6 months, and1year) 
18) EuroQol-5D (pre-op, 3 months, 6 months, 1, 2, 3, 4, and 5 years) 
19) Health Resource Utilization Diary (1 month, 3 months, 6 months, 1 year) 
20) Report of Second Cervical Surgery 
21) Death Form 
22) Inpatient Hospital and Rehabilitation Utilization Data Sheet 
23) Long term follow-up phone questionnaire (2, 3, 4, and 5 years) 
 
 
 
b. Study endpoints. 
 
Subjects will be followed for 5 years.  The primary endpoint will be the 1-year change in 
SF-36 physical component summary score (PCS) at one year.  Secondary endpoints will 
include the 1-year change in mJOA, NDI, and EuroQol-5D scores as well as the observed 
complication rates, health service utilization, work status, and sagittal balance 
measurements.   
 
c. Statistical Methods. 
 
Primary analyses will include all subjects randomized using an intent-to-treat 
approach. The primary endpoint is the 1-year change in Physical Component Summary of 
the SF-36 (SF-36 PCS) at one year. A likelihood-based analysis using a mixed model will 
be used to compare SF-36 PCS between groups. This model will adjust for baseline SF-
36 PCS, as well as study surgeon using a random effects model.  All time points will be 
included in the model, and each subject will contribute data for the time points at which 
they were assessed.  The model enables a statistical comparison between treatment 
groups at each time point, though the comparison at the one-year time point will be the 
primary analysis.  The primary advantage of the mixed model, when compared to 
commonly used methods such as complete case analysis and single imputation (e.g. last 
observation carried forward), is its flexibility in handling missing data. This analysis will 
assume that missing data occurs at random (i.e. the missing data value can be dependent 
on observed data, but independent of unobserved data). The inclusion of all follow-up 
time points in the model as well as covariates identified to be associated with withdrawal 
will assist in meeting this assumption and minimizing the risk of bias.  Although the 
assumption for missing data is weaker under the likelihood based analysis compared to 
complete case analysis, a non-ignorable missing data mechanism is possible. Sensitivity 
analysis using selection and pattern mixture models will be employed to evaluate the 
robustness of conclusions to the missing at random (MAR) assumption.  
 

Analysis Plan for Year 2 Outcomes 
 
Year 2 outcomes for SF-36 and other continuous outcomes will be analyzed using 
linear mixed effects models (lme) that include both first and second year outcomes. The 
outcomes will be change from baseline. The purpose of the lme is to address missing 
second year outcomes. Since the year 2 assessments were missing mainly for logistical 
reasons (at 2 sites, research staff neglected to follow up with participants during specific 
time intervals), the missing at random (MAR) assumption of the lme is valid. The model 
will include treatment group, time period, and group*time interaction. To address within-
subject correlation, patient id will be a random effect. There will be no adjustment for 
surgeon, since some surgeons had few patients, and no adjustment for baseline variables, 
since these were similar between groups. The treatment effect at year 2 will be tested 
using model contrasts. The year 1 treatment effect will be tested similarly, to confirm 
previous analyses obtained by t-test and anova. The models will be used to compare the 2 
randomized groups and the “as treated groups.” We will not address multiple 
comparisons for the “as treated” analyses because they are considered to be exploratory.  
 
Analysis Plan for Return to Work 
 
The return to work analysis will include all time periods up to 12 months (1, 3, 6, 
and 12 months). Groups will be compared via Kaplan-Meier plots and log-rank tests. To 
address multiple comparisons when comparing the as-treated groups pairwise 
comparisons will be performed at p=0.025 to account for 2 comparisons (DL vs DF and 
DL vs VF).  
 
Analysis Plan for Health Resource Utilization 
 
The research team has extensive experience conducting economic evaluations, 
including assessment of musculoskeletal interventions alongside RCTs and will conduct 
the proposed patient-oriented health resource utilization analysis.  We will collect health 
resource utilization data alongside this RCT.  The primary goal of this data collection will 
be to provide future patients with rigorous, high quality data regarding expected health 
resource utilization following different surgical procedures for CSM.  The collected 
health resource utilization data will empower patients and will help patients choose the 
right procedure for their particular social and economic circumstances, as well as inform 
and be useful to all other stakeholders. 
 
d. Power Analysis.   
 
Sample size for Specific Aim #1a (Ventral surgery is associated with superior SF-36 
PCS outcome at one year compared to dorsal (fusion or laminoplasty surgery): 
Sample size estimates were calculated based on analysis of covariance model with α= 0.05 at 
80% and 90% power using Power Analysis and Sample Size software (PASS 2008, NCSS, 
LLC. Kaysville, Utah). The primary endpoint is the SF-36 PCS. This component of the SF-

36 is derived from the sums of scores of 21 items and thus exhibits distributional behavior 
commensurate with assumptions for parametric analysis. Our preliminary data suggest 
standard deviations for SF-36 PCS between 10 and 12 and correlations of baseline with one 
year SF-36 PCS between 0.6 and 0.7. The following table describes the total sample size (2:3 
ventral-dorsal randomization) required to detect a five point difference in SF-36 PCS one 
year post-surgery for various combinations of power, standard deviation and one year 
correlations under a fixed design.  
 
A minimum sample size of 137 patients provides at least 90% power (see Tables below): 
 
Surgery (N) 
Pre-op 
Post-Op 
Correlation 
between Pre- and 
Post-Op 
Difference 
Ventral (45) 
35.5 ± 10.3 
44.2 ± 11.7 
0.64 
+ 8.7 ± 8.2 
Dorsal (70) 
35.8 ± 11.3 
39.8 ± 11.6 
0.66 
+ 4.0 ± 9.5 
Dorsal Fusion (42) 
 35.0 ± 11.7 
 39.6 ± 12.4 
0.65 
+ 4.6 ± 10.0 
Laminoplasty (28) 
 37.0 ± 10.9 
 40.1 ± 10.6 
0.67 
+ 3.1 ± 8.8 
All patients (115) 
35.7 ± 10.9 
41.5 ± 11.8 
0.64 
+ 5.8 ± 9.7 
 
 
Difference / 
SD 
Correlation 
80% Power /  
5% Type I error (2-sided) 
90% Power /  
5% Type I error (2-sided) 
NVentral 
NDorsal 
N 
NVentral 
NDorsal 
N 
5 / SD = 10 
0.60 
38 
56 
94 
50 
74 
124 
5 / SD = 10 
0.65 
40 
59 
99 
53 
78 
131 
5 / SD = 10 
0.70 
42 
62 
104 
55 
82 
137 
 
 
The sample size will be inflated by 5% to accommodate multiple significance testing using 
an Obrien-Fleming stopping boundary. Based on our preliminary data and pilot studies, 
withdrawal and loss-to-follow-up are not expected to be high. The sample size will be further 
inflated by 10% to accommodate attrition during the follow-up. Thus, 159 total patients will be 
recruited and randomized. Ten high volume surgeons/ centers with the necessary expertise to 
permit patient randomization (16 randomized CSM cases/ site) have been selected to 
achieve the goal of enrolling 159 randomized patients over 18 months.  An additional 91 
nonrandomized patients will be enrolled into the study. 
 
 
Sample size for Specific Aim #1b (Compared to pre-operative baseline status, both ventral 
and dorsal surgery for CSM improve symptoms of spinal cord dysfunction at one year 
follow-up): 
 
Using the sample size estimate for Specific Aim #1a and assuming ~10% attrition during 
follow-up, we expect to have 55 ventral surgery and 82 dorsal surgery patients (total = 137 
patients) available for analysis.  We will be able to detect changes from baseline pre-operative 

mJOA status as small as 2.0 points (clinically important difference) for both the ventral surgery 
cohort and the dorsal surgery cohorts at one year.   Assumptions for this sample size analysis 
include Type I alpha = 0.025, power at 90%, and range of within-subject correlation of 0.60 to 
0.70. 
 
 
H. 
Economic Considerations 
 
No subject will incur any additional cost for participating in this study.  All of the pre- 
and post-operative CT, MRI, flexion-extenstion x-rays, and pre-operative sagittal balance 
films are considered standard of care.  The post-operative sagittal balance films, which 
only randomized patients will receive, are not considered standard of care and will be 
billed directly to the research fund.  All costs associated with the adminstration of the 
study will be assumed by the Patient-Centered Outcomes Research Institute (PCORI) 
and/or the Lahey Comparative Effectiveness Research Institute. 
 
 
 
 
III.    HUMAN SUBJECTS 
 
 
A. 
Subject Population, Recruitment 
 
Eligibility Criteria: Patients aged 45-80 years with CSM (≥2 levels of spinal cord compression 
from C3 to C7) presenting with ≥2 of the following symptoms/signs: clumsy hands, gait 
disturbance, hyperreflexia, up going toes, bladder dysfunction. 
 
Exclusion Criteria: Any of the following: C2-C7 kyphosis>5º (measured in standing neutral 
cervical spine radiograph), segmental kyphotic deformity (defined by ≥3 osteophytes extending 
dorsal to a C2-C7 dorsal-caudal line measured on cervical spine CT), structurally significant 
ossification of posterior longitudinal ligament (OPLL – measured on cervical spine CT), 
previous cervical spine surgery, or significant active health-related co-morbidity (Anesthesia 
Class IV or higher). 
 
EXCLUDE 
 
 
 
INCLUDE 

   
 
 
 
Segmental-Cervical 
Kyphotic Deformity 
 
Yes 
 
 
 
 
No 
 
 
 
 
Figure.  Two cases with sagittal CT reconstructed images are depicted.  A line is drawn from the dorsal caudal point 
of C2 to the dorsal caudal point of C7.  If 3 or more levels of disc-osteophyte extend dorsal to the line, then the case 
has a segmental-cervical kyphotic deformity and the case would be excluded from the study.  The C2-C7 Cobb 
angle is 5 degrees lordosis in both cases 
  
 
Subjects will be enrolled by participating spine surgeons who are investigators in the 
study.  These subjects will be identified within the existing practice of each surgeon.  
There will be no advertising or any effort to recruit subjects into the study from outside 
the practice of a study surgeon investigator. 
Once a patient has been screened, identified as having CSM, and agreed to participate in 
the trial by signing consent, the subject will undergo two reviews.  The patient’s images 
will first be reviewed by a Central Review Committee (Zoher Ghogawala, MD and 
Robert Whitmore, MD) to confirm eligibility.  If the patient is deemed eligible, their 
images will then be reviewed by the spinal experts network.  The patient’s images will be 
uploaded onto the web-based platform, and an email will be generated and sent to all 15 
members (15 CSM surgeon investigators) of the spinal experts panel. Each surgeon will 
be asked to vote: ‘randomize’ or ‘do not randomize’ and then to characterize his/her 
preferred surgical approach as ventral or dorsal. If after 72 hours, a majority (>50%) of 
the review panel (with at least 9 votes for a quorum) favor randomization (equipoise) and 
less than 80% select one approach (ventral or dorsal) over another, then the patient will 
be eligible for study randomization. 
 
2/1/1937
2/1/1937
FF
Page: 2 of 3
Page: 2 of 3
Acq no: 0
Acq no: 0
KVp: 140
KVp: 140
mA: 200
mA: 200
Tilt: 0
Tilt: 0
RD: 120
RD: 120
CT CERVICAL SP NC W/ REFORMATS
CT CERVICAL SP NC W/ REFORMATS
Average
Average
7/20/2003 08:28:55
7/20/2003 08:28:55
000500571
000500571
LOC: 17.98
LOC: 17.98
THK: 3
THK: 3
HFS
HFS
IM: 8 SE: 577
IM: 8 SE: 577
Compressed 8 :1
Compressed 8 :1
W: 1600
W: 1600
C: 400
C: 400
Z: 0.73
Z: 0.73
AA
PP
HH
FF

The results of the voting (the number of votes randomize or do not randomize and the 
number of ventral or dorsal votes) will be available to the patient both to increase patient 
trust and confidence in the recommendation for randomization, as well as to protect 
patients from undergoing randomization when one approach (ventral or dorsal) might be 
superior for that patient. 
 
Patient Randomization (See Figure 1 Below) 
Patients will be offered randomization in a subsequent one-hour meeting (following spinal 
experts review of the case) among study coordinator, surgeon, and patient if two conditions are 
met: 
1) Central Review Committee (Zoher Ghogawala, MD and Robert Whitmore, MD) checked 
the images and clinical exam findings and found the patient eligible; and 
2) Spinal Experts Panel confirmed patient’s eligibility (>50% majority vote “randomize” 
and less than 80% select one approach (ventral or dorsal) over another). 
The patient can either consent to or decline randomization. There will be two categories 
of patients who have signed an IRB-approved consent to participate in the study: 
1. Randomized cohort: Upon confirmation of eligibility and patient acceptance of 
randomization, the study coordinator will access the assignment by logging into the 
secure website (https://pip.acesis.com) with a password and will obtain the 
randomization assignment from the web-based platform with its pre-programmed 
blocked (2, 4, or 6 subjects/block) stratified site-specific randomization scheme. 
Randomized patients will be followed for five years.  
2. Non-Randomized cohort: The non-randomized cohort will consist of all patients who 
meet entry criteria but for whom equipoise is not confirmed by spinal experts panel.  
It also will consist of patients who do not consent to randomization.  All non-
randomized patients will be asked to complete all the study questionnaires and will be 
followed for five years. The non-randomized cohort will not have an independent 
radiologist evaluation. 

 
 
B. 
Source of Research Material 

 
Subjects will be identified from within the practice of spine surgeon investigators. 
 
C. 
Consent Procedures 
 
Subjects will be identified by investigator spine surgeons within their practice.  Subjects 
will be registered by the surgeon's office.  The subjects will be clearly told by the surgeon 
that participation is voluntary and that a decision not to participate will not affect their 
medical care in any way.  The patient will sign a consent form with the spine surgeon 
after having a chance to review the study protocol and consent form with family and 
others.   The subjects will sign the consent with the surgeon during a separate office visit 
prior to surgery.  A spine study coordinator will then contact the patient for more detailed 
questions regarding registration for the study (e.g. home phone number and home 
address).  The study coordinator will also ask the patient whether he is comfortable 
enrolling in the study.   
 
D. 
Risks 
 
All of the subjects in the study will be surgical candidates and would have had surgery 
recommended even if they were not involved in a study. 
 
 
E. 
Protection of Subjects 
 
All subjects will receive standard follow-up by the treating surgeon.  All of the surgical 
procedures are considered standard care and none are considered investigational.  The 
results will be made available to the subjects prior to publication.  Any significant 
findings regarding the overall safety of either procedure at any site will be brought to the 
attention of all subjects in the study once all of the appropriate IRB committees have 
been notified.  The confidentiality of all subjects will be assured by assigning all subjects 
a code and by removing all identifying information from questionnaires.  Data entered 
into the study web site will be encrypted using the current industry standard to protect 
patient confidentiality. 
 
Once the database is analyzed, all patient identifiers will be removed from the final 
database.   The database will be kept at the Lahey Comparative Effectiveness Research 
Institute.  No patient identification would be linked to the data. 
 
F. 
Data and Safety Monitoring Plan 
 
(As outlined above in Research Plan) 
 
G. 
Confidentiality 
 
Each subject will be assigned a code number and no identifying information will leave 
the Lahey Comparative Effectiveness Research Institute.  Data from each patient will be 

sent to the Lahey Comparative Effectiveness Research Institute or will be entered into the 
study web site which is encrypted to protect patient confidentiality using the current 
industry standard.  All patient identifiers will be removed from the final database.  
 
H. 
Potential Benefits 
 
Subjects will be followed closely and might gain from the increased observation. Each 
subject will be offered a free review of their radiographic images by a panel of spinal 
experts. The multiple opinions from other surgeons will be used to help educate subjects 
about their condition. The subjects will have the opportunity to learn about the results of 
the study through frequent updates available from the Lahey Comparative Effectiveness 
Research Institute or from the public web page (https://pip.acesis.com). 
  
Society at large might benefit from the results of this study.  The study will be useful for 
spine surgeons to determine if health resource utilization differs among the three surgical 
procedures for people with cervical spondylotic myelopathy. 
 
 
I. 
The Risk-Benefit Ratio 
 
All subjects entered into the study would be surgical candidates for either surgical 
procedure in the study.  All of the surgical procedures used in this study are routine and 
constitute standard care.  No procedure is considered investigational.  Therefore, no 
subject will have any increased risk of physical injury as a result of participation in the 
study.  The subjects will have access to the Study website and will be informed of the 
results of the study prior to publication.  The increased level of observation will possibly 
benefit some of the subjects.  The subjects will know that they are helping society at large 
because the results of the study will be useful for spine surgeons to help future subjects 
determine which surgical procedure is best for people with cervical spondylotic 
myelopathy. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
Appendix I: Study Schema 
 
 
 
Patient identified as CSM surgical candidate 
Clinician confirms patient eligibility - Consent form signed 
Assessment of Complications  
Health Cost Diary 
  
Pre-op Questionnaires  
NDI, SF-36, mJOA, EQ-5D 
Spinal Experts Review 
> 50% majority of Spinal experts vote in favor of 
randomization 
Yes 
No 
 Assessment of Complications 
Health Cost Diary 
Pre-op imaging: Cervical flexion-extension films; sagittal balance films, 
cervical MRI, and cervical CT 
Do Not Randomize 
6 months 
Randomize 
Ventral or Dorsal Surgery 
1 month 
3 months 
SF-36, NDI, mJOA, EQ-5D 
Health Cost Diary 
Cervical Spine MRI 
1 year 
SF-36, NDI, mJOA, EQ-5D 
Health Cost Diary 
SF-36, NDI, mJOA, EQ-5D 
Health Cost Diary 
Flexion-extension cervical plain 
films and cervical CT (if NDI>30 or 
plain films suggest instability) 
SF-36, NDI, mJOA, EQ-5D 
Health Cost Diary 
SF-36, NDI, mJOA, EQ-5D 
Health Cost Diary 
Flexion-extension cervical plain 
films,sagittal balance films, and 
cervical CT (if NDI>30 or plain films 
suggest instability) 
2, 3, 4, and 5 
years
SF-36, NDI, EQ-5D 
Telephone follow-up  
(Re-operations, work status) 
SF-36, NDI, EQ-5D 
Telephone follow-up 
(Re-operations, work status) 
CSM Study Flow 
Schema 
Independent 
Radiology Review 
SF-36, NDI, mJOA, EQ-5D 
Health Cost Diary 
Cervical Spine MRI