This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Efficacy and Safety of Integra Accell Evo3 DBM in Instrumented Lumbar Spine Fusion (NCT01714804), a na na study. The primary outcome is Number of Levels With Posterolateral Fusion.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01714804 |
| Phase | NA |
| Condition | Stenosis, Spondylosis, Degenerative Changes |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 30 |
| Arms in the primary outcome | n/a |
| Lead sponsor | SeaSpine, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The registry lists 30 participants and conditions including stenosis, spondylosis, and degenerative changes. The study concerns instrumented lumbar spine fusion; further eligibility criteria are not reported in the registry record.
Intervention
Accell Evo3, a demineralized bone matrix device, was evaluated prospectively as an adjunct for instrumented lumbar spine fusion. The intervention is recorded as a device, and the prospective arm is described as Accell Evo3.
Comparator
The study objective describes a retrospective comparison with a historical patient cohort. The record also lists an Infuse group in the adverse-event information, but this is not a randomized, like-for-like control comparison. Details of the historical cohort and how it was assembled are not reported in the registry record.
Primary question
The primary endpoint is the number of lumbar levels with posterolateral fusion at 12 months. Each spinal level is assessed separately using X-ray and/or CT. Numerical results for this endpoint are not reported in the registry record, so the record does not establish the observed fusion result or its precision.
3. Trial Design
This is a prospective, single-group study of Accell Evo3 in instrumented lumbar spine fusion. The registry lists enrollment as 30 and status as completed. The study start is recorded as 2012-08 and primary completion as 2016-07. The sponsor is SeaSpine, Inc. The phase is recorded as NA.
The study objective was to evaluate the performance of Accell Evo3 as an adjunct to fusion and to make a retrospective comparison with a historical patient cohort. That objective does not make the design randomized. Allocation is recorded as NA, masking as none, and the model as single group. The registry specifically cautions that the arms are not a like-for-like control comparison. Differences between a prospective cohort and a historical cohort could reflect differences in patient selection, care, measurement, or follow-up as well as any difference associated with the intervention.
The prospective arm is described as Accell Evo3. The adverse-event record separately lists Accell Evo3 and Infuse groups. The appearance of both groups in safety information should not be interpreted as evidence of random assignment or a controlled efficacy comparison. The record does not provide the historical cohort's selection rules, timing, baseline characteristics, or how outcomes were compared.
The primary endpoint is fusion level count at 12 months. Secondary outcomes listed are the Oswestry Disability Index and Visual Analog Scale measures for back and leg pain. The record lists two outcome measures and zero analyses. It does not provide numerical results for the primary or secondary outcomes. Thus, the design and intended questions can be described, but an estimate of efficacy or a comparative treatment effect cannot be reconstructed from the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Accell Evo3 | Infuse |
|---|---|---|
| STARTED | 30 | 30 |
| COMPLETED | 29 | 30 |
| NOT COMPLETED | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: One level is defined as a spinal segment in the lumbar spine.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Prospective | Retrospective | Total |
|---|---|---|---|---|
| Participants analysed | 29 | 30 | 59 | |
| Age, Customized: >18 years old | Participants | 29 | 30 | 59 |
| Sex: Female, Male: Female | Participants | 16 | 17 | 33 |
| Sex: Female, Male: Male | Participants | 13 | 13 | 26 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Region of Enrollment: United States | participants | 29 | 30 | 59 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Levels With Posterolateral Fusion, measured over 12 months.
| Element | Registry entry |
|---|---|
| Result type | Count Of Units |
| Measure of spread | not applicable |
| Unit | levels |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of levels with posterolateral fusion at 12 months. A level is defined as a spinal segment in the lumbar spine. Fusion was assessed in the posterolateral space using X-ray and/or CT, with each spinal level graded separately. The registry description says assessment was performed by the operating surgeon, described as blinded towards the patient.
A level count captures the extent of fusion across the assessed lumbar segments rather than reducing the endpoint to a single yes-or-no status for an entire participant. That can be useful when the number of treated spinal levels varies, although interpretation depends on knowing which levels were eligible for assessment, how the grading categories were defined, and how counts were summarized. Those details are not reported in the registry record.
Fusion is used as a structural endpoint in this study because the stated objective is to evaluate a bone matrix adjunct in instrumented lumbar fusion. It is not interchangeable with measures of pain or function. ODI and back and leg VAS are listed as secondary outcomes, but their numerical results are not reported. The primary endpoint result itself is also not reported, so the endpoint's observed value, variability, and uncertainty cannot be assessed from this record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinical question and an endpoint but does not report the primary endpoint's numerical result. It therefore supports a description of what was intended to be measured, not a conclusion about the observed number of fused levels. Without a reported summary, the magnitude and variability of the endpoint cannot be assessed. A reader cannot determine from the record whether results were consistent across participants or spinal levels.
The study's prospective Accell Evo3 arm and its intended retrospective historical comparison are not equivalent to a randomized comparison. Random allocation can help balance prognostic factors between groups; a historical comparison does not provide that protection. Differences between cohorts could arise from patient characteristics, clinical practice, assessment methods, follow-up, or other factors. The registry itself cautions that the arms are not a like-for-like control comparison. The comparative objective should therefore not be mistaken for evidence of a causal treatment contrast.
The record lists safety counts for Accell Evo3 and Infuse. These counts describe recorded events in groups with different numbers at risk, and they are not accompanied by adjusted comparisons, uncertainty estimates, or information about group comparability. They can be read as descriptive registry figures, but not as evidence that one group has greater or lesser risk. The listed deaths are zero in both groups; this statement describes the recorded counts and does not establish that all possible harms were absent.
For the primary outcome, the record gives a timeframe of 12 months and describes imaging-based assessment at each spinal level. It does not provide an effect estimate, confidence interval, or statistical test. A confidence interval, in general, describes the range of values compatible with the data and the method used to calculate it; without a reported estimate and interval, precision cannot be judged. The record lists zero analyses, so no reported inferential result can be used to quantify evidence against a null hypothesis.
ODI and VAS for back and leg pain are identified as secondary outcomes, but there are no numerical results for them in the registry record. No pattern of change, between-group difference, or uncertainty for these measures can be described. Similarly, although the study objective mentions a historical comparison, the record does not report the comparison's outcome data or methods. The appropriate interpretation is therefore bounded: the registry records a completed prospective evaluation and a defined endpoint, while leaving the primary and secondary outcome results unavailable.
9. Statistical Methods Explained
What does a single-group design mean?
A single-group design follows participants receiving the intervention without randomized assignment to a concurrent control group. It can describe outcomes observed in that group, but by itself it cannot separate an intervention-associated outcome from the influence of participant characteristics, clinical care, natural history, or other factors. Here, the registry records a prospective Accell Evo3 group and describes an intended retrospective comparison with a historical cohort. The record cautions that the arms are not a like-for-like control comparison. Details that would allow a reader to judge comparability are not reported in the registry record.
Masking is recorded as none. The endpoint description says the operating surgeon was blinded towards the patient, but does not say that the assessor was blinded to treatment assignment. These statements should not be expanded into a claim of blinded outcome assessment. Whether assessment was standardized across participants and cohorts is not reported in the registry record.
How should a level count be understood?
The primary outcome is a count of spinal levels with posterolateral fusion at 12 months. Counts describe how many units meet a stated condition. The registry defines a unit as a lumbar spinal segment and says each level was graded separately from X-ray and/or CT assessment. A count endpoint can have different distributions depending on how many levels are assessed per participant and how often a level meets the fusion criteria. The number of eligible levels, grading rules, and summary method are not reported in the registry record.
For count data, a statistical analysis may need to account for the range and distribution of possible counts. When observations vary more than a simple model expects, over-dispersion can make standard errors too small if the model does not allow for that extra variability. This is a general statistical consideration, not a description of the analysis used in this study. The registry lists zero analyses and does not report a model, distributional assumptions, or a variance method.
There may also be a relationship between levels from the same participant: outcomes at multiple levels in one person need not behave as independent observations. Analyses that treat all levels as independent can understate uncertainty when within-participant outcomes are correlated. This is another general issue for level-based endpoints. The registry does not report whether the analysis accounted for clustering by participant, nor does it report enough results to assess that choice.
What can a confidence interval tell the reader?
In general, a confidence interval expresses uncertainty around an estimate under a specified statistical method. Its width depends on the data and the method; a narrow interval indicates greater precision than a wide interval in the context of that same method. A point estimate without an interval gives less information about precision, while an interval does not correct weaknesses in design or measurement. The registry record contains no numerical primary endpoint estimate or confidence interval. It is therefore not possible to judge the precision of the fusion result from this record.
A test result, when reported, addresses compatibility of observed data with a specified statistical hypothesis and assumptions. It does not by itself measure clinical importance or establish causality. The record lists zero analyses and does not report a test statistic or p-value for the primary endpoint. No such inferential conclusion can be attributed to the registry record.
What does the planning illustration represent?
The registry's sample-size assumptions describe a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is defined as a stated fraction of the observed effect. These are planning assumptions, not the trial's own design justification. The record does not report the trial's sample-size justification, and the illustration does not represent observed power. A planning sample size is a hypothetical number of participants for a future study under stated assumptions; it is not a measure of how likely the completed study was to detect an effect after the fact.
Because the registry record does not report the observed effect or the numerical planning outputs, no planning total can be stated from it. The illustration's assumptions should also be considered separately from this study's single-group, nonrandomized design. In particular, equal allocation between two arms is an assumption for the planning illustration, not evidence that participants in this study were allocated equally or randomly.
Which analysis details are unavailable?
The record does not describe the statistical method for summarizing the count endpoint, adjustment for participant or level characteristics, handling of missing outcome observations, or the analysis population. It does not report whether any analyses were prespecified or whether the primary endpoint was assessed at participant level, level level, or both. These omissions prevent a detailed audit of the analysis plan. General statistical principles can explain why these choices matter, but cannot identify which choices were made in this study.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists the primary endpoint as the number of levels with posterolateral fusion at 12 months. It also lists ODI and VAS for back and leg pain as secondary outcomes. When several outcomes are evaluated, the chance of at least one apparently unusual finding can increase if each is tested separately without accounting for the collection of tests. A prespecified hierarchy, adjustment method, or clear distinction between confirmatory and exploratory outcomes can help readers interpret multiple results. Such a multiplicity strategy is not reported in the registry record.
The record lists zero analyses and provides no numerical outcome results. It does not report which outcomes were analyzed, whether there were additional analyses, or whether any adjustments for multiple testing were used. Consequently, the number and interpretation of statistical tests cannot be evaluated from this record.
Missing-data handling is not reported in the registry record. The registry lists enrollment as 30 and the safety groups as having 29 and 30 at risk, but does not explain why the safety denominators differ or whether outcome availability varied. It does not report the number of participants with primary endpoint observations, reasons for missing imaging, or any imputation or sensitivity methods. An outcome analysis may be affected if missingness is related to participant characteristics or outcomes; this is a general concern, not a claim about what occurred in this study.
The analysis populations are also not reported. The record does not say whether the primary analysis included all enrolled participants, only those with evaluable imaging, or another defined group. Without these details, readers cannot establish which participants contribute to the endpoint or how missing observations affect its interpretation.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Accell Evo3 | 7 | 29 | 24.1% |
| Infuse | 2 | 30 | 6.7% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Accell Evo3 | 0 of 29 |
| Infuse | 0 of 30 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Accell Evo3 | 6 of 29 |
| Infuse | 6 of 30 |
Most frequent serious adverse event terms
| Event term | Organ system | Accell Evo3 | Infuse |
|---|---|---|---|
| Adjacent segment disease | Musculoskeletal and connective tissue disorders | 2 of 29 | 1 of 30 |
| Hematoma | Skin and subcutaneous tissue disorders | 1 of 29 | 0 of 30 |
| epidural hematoma | Skin and subcutaneous tissue disorders | 0 of 29 | 1 of 30 |
| Blood Pressure increase | Cardiac disorders | 1 of 29 | 0 of 30 |
| Cataract surgery | Eye disorders | 1 of 29 | 0 of 30 |
| Dysphagia | Gastrointestinal disorders | 1 of 29 | 0 of 30 |
| carpal tunnel trigger finger | Musculoskeletal and connective tissue disorders | 1 of 29 | 0 of 30 |
| CMC arthroplasty, thumb | Musculoskeletal and connective tissue disorders | 1 of 29 | 0 of 30 |
| headache, rib and back pain | Musculoskeletal and connective tissue disorders | 1 of 29 | 0 of 30 |
| Upper extremity numbness; guyon's canal release | Musculoskeletal and connective tissue disorders | 1 of 29 | 0 of 30 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Accell Evo3 | Infuse |
|---|---|---|---|
| Numbness | Nervous system disorders | 2 of 29 | 0 of 30 |
| Adjacent segment disease | Musculoskeletal and connective tissue disorders | 0 of 29 | 2 of 30 |
| Back and thigh pain (stinging) | Musculoskeletal and connective tissue disorders | 1 of 29 | 0 of 30 |
| Fever and burning around incision | Infections and infestations | 1 of 29 | 0 of 30 |
| Urinary retention | Renal and urinary disorders | 1 of 29 | 0 of 30 |
| Urinary tract infection | Renal and urinary disorders | 0 of 29 | 1 of 30 |
| Dysuria/stress incontinence | Renal and urinary disorders | 0 of 29 | 1 of 30 |
| Erythema | Skin and subcutaneous tissue disorders | 0 of 29 | 1 of 30 |
| Neck and low back pain | Musculoskeletal and connective tissue disorders | 1 of 29 | 0 of 30 |
| Low back pain | Musculoskeletal and connective tissue disorders | 1 of 29 | 0 of 30 |
Serious events with the highest arm-level rate: adjacent segment disease (6.9%), hematoma (3.4%), blood pressure increase (3.4%), cataract surgery (3.4%), dysphagia (3.4%).
The registry lists serious adverse events for 7 of 29 participants at risk in the Accell Evo3 group and 2 of 30 at risk in the Infuse group. Other adverse events are listed for 6 of 29 and 6 of 30, respectively. Deaths are listed as 0 in both groups. These are descriptive counts in the registry record; they do not establish that the groups are comparable or that differences between the counts were caused by treatment.
The record lists serious adverse-event terms with percentages: Adjacent segment disease, 6.9%; Hematoma, 3.4%; Blood Pressure increase, 3.4%; Cataract surgery, 3.4%; Dysphagia, 3.4%; and carpal tunnel trigger finger, 3.4%. The available information does not provide a detailed account of event timing, recurrence, severity grading, relatedness assessment, or participant-level overlap. The percentages should not be treated as comparative risks without the corresponding definitions and analysis.
Safety counts can differ because of group size, follow-up, event ascertainment, or underlying participant differences. The registry cautions that the groups are not a like-for-like control comparison. No adjusted estimates or uncertainty intervals are reported, so the counts support a description of recorded events, not a comparative safety conclusion.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a prospective evaluation of Accell Evo3 was conducted and marked completed. Its stated objective was to evaluate Accell Evo3 as an adjunct for instrumented lumbar spine fusion, with a retrospective comparison to a historical patient cohort. The primary endpoint is clearly identified as the number of levels with posterolateral fusion at 12 months, assessed with X-ray and/or CT. These details tell readers what was studied and what the primary outcome was intended to represent.
The record does not report the primary endpoint's numerical result. It therefore does not establish the observed fusion count, its variability, or the precision of any estimate. It also does not report numerical results for the listed secondary outcomes of ODI and back and leg VAS. No outcome change, group contrast, or statistical significance can be inferred from the endpoint descriptions alone.
The record's historical comparison objective does not establish a causal effect. Allocation is recorded as NA, the model as single group, and the registry cautions that the arms are not a like-for-like control comparison. Historical cohorts may differ in ways that matter to outcomes, and the record does not describe the methods used to select or align the cohorts. The Infuse safety group does not by itself provide a randomized efficacy comparator.
Safety information is available as event counts and a list of serious-event terms with percentages. Those figures describe what the record lists, but do not provide adjusted comparisons or a complete account of ascertainment and follow-up. Zero recorded deaths in the listed groups should be read as a count, not as proof that no risk exists.
In short, the registry record supports a description of the study design, endpoints, and posted safety counts. It does not provide enough outcome or analysis information to determine the size, precision, or causal interpretation of an efficacy result.
13. Why This Trial Matters Statistically
This study raises statistical issues common to evaluations that combine a prospective intervention cohort with historical information. The distinction between describing outcomes in a treated group and estimating a comparative treatment effect is central. A prospective cohort may use a defined endpoint and follow-up, but a retrospective comparator can differ in participant selection, measurement, and care. Those differences limit direct causal interpretation unless they are carefully addressed and reported.
The endpoint also illustrates a unit-of-analysis question. The primary measure counts fused lumbar levels, and each level is graded separately. Participants may contribute information from more than one level, so an analysis must distinguish the number of levels observed from the number of independent participants. Appropriate handling of within-participant dependence matters to uncertainty estimates. The registry does not report how this issue was addressed.
Outcome availability is another important part of interpretation. A 12-month imaging endpoint depends on having an evaluable assessment at the relevant time. The registry does not report missingness, reasons for unavailable assessments, or the analysis population. Without those details, readers cannot judge whether the endpoint summary represents all enrolled participants or a subset.
Finally, the registry lists both a primary endpoint and patient-reported secondary outcomes, while reporting no analyses. Clear outcome reporting is necessary for readers to evaluate effect size, uncertainty, and the role of multiple outcomes. This record shows why a defined endpoint and completed study status are not substitutes for posted numerical results and analysis methods. The safety counts add descriptive information, but do not resolve the limitations of the nonrandomized comparison.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary limitation for interpretation is that the registry record does not report numerical results for the primary fusion endpoint. Although the measure, assessment approach, and 12-month timeframe are specified, no summary value, variability measure, or uncertainty interval is available. The listed secondary outcomes also lack numerical results in the record.
The study is recorded as a single-group model with allocation NA and no masking. Its stated retrospective comparison with a historical cohort cannot be interpreted as randomized evidence. The registry explicitly cautions that the arms are not a like-for-like control comparison. Details needed to assess cohort comparability, including selection and baseline characteristics, are not reported in the registry record.
Measurement information is limited. The endpoint description specifies X-ray and/or CT and separate grading of each level, but does not provide grading criteria, the number of eligible levels, or procedures for resolving uncertain assessments. The statement that the operating surgeon was blinded towards the patient does not establish that the assessor was blinded to treatment. Further assessment procedures are not reported.
The record lists zero analyses and does not report the statistical methods, analysis population, missing-data handling, multiplicity approach, or sample-size justification. It also does not describe follow-up completeness for efficacy outcomes. Safety figures are descriptive and lack reported adjustment, uncertainty, or enough detail about ascertainment and event timing to support a comparative risk estimate. These limitations reflect what is not reported in the registry record and should not be taken as evidence that a particular method was or was not used outside the record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Efficacy and Safety of Integra Accell Evo3 DBM in Instrumented Lumbar Spine Fusion — NCT01714804.
- Registry record last updated 2018-01-23; status last verified 2017-12.
- Results first posted 2017-12-20.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT01714804 is a completed prospective, single-group evaluation of Accell Evo3 as an adjunct to instrumented lumbar spine fusion. The registry lists enrollment as 30, sponsor SeaSpine, Inc., start 2012-08, and primary completion 2016-07. Allocation is recorded as NA and masking as none.
The primary endpoint is the number of levels with posterolateral fusion at 12 months, assessed using X-ray and/or CT. ODI and VAS for back and leg pain are listed as secondary outcomes. Numerical results for these outcomes and statistical analyses are not reported in the registry record.
The record lists serious and other adverse-event counts for Accell Evo3 and Infuse groups, with zero deaths listed in each. It cautions that the groups are not a like-for-like control comparison. The study objective describes a retrospective comparison with a historical patient cohort, but cohort details and comparative outcome analyses are not reported.