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 Single-Armed Use of ViviGen Cellular Bone Matrix in Patients Undergoing Posterolateral Lumbar Surgery (NCT04007094), a na na study. The primary outcome is The Number of Surgical Levels With Successful Lumbar Fusion.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04007094 |
| Phase | NA |
| Condition | Degenerative Disc Disease, Spinal Stenosis, Spondylosis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 21 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Ohio State University |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned patients undergoing posterolateral lumbar fusion without interbody fusion. The listed conditions were degenerative disc disease, spinal stenosis, spondylosis and spondylolisthesis. The registry record describes the intended assessment across one or multiple continuous levels of the lumbosacral spine, from L1-S1.
Intervention
The intervention was ViviGen Cellular Bone Matrix, a cellular bone matrix used to supplement fusion. The study was prospective and single-arm. Its description states that one side of the fusion was coated with milled local autograft bone and the opposite side was supplemented with an equal volume of ViviGen.
Comparator
There was no separate randomized control arm. Local autograft and ViviGen were assigned to opposite sides within the same operative fusion, as described in the study arm. This is an internal side-to-side arrangement, not a like-for-like comparison between independent treatment groups; the registry record does not report a randomized allocation procedure.
Primary question
The primary question was how many surgical levels met the registry’s definition of successful lumbar fusion at 12 months after surgery. Fusion extent was assessed using the Lenke classification: grade A was defined as radiographic success, grade B as partial success, and grades C and D as radiographic failure. The registry record does not report the observed counts for these categories or a statistical comparison between sides.
3. Trial Design
This was a prospective, single-arm post-market study sponsored by Ohio State University. The registry lists the study as terminated and records enrollment of 21. Its recorded phase is NA. The study began on 2019-02-12, and primary completion is recorded as 2022-01-21. Masking is listed as none, while allocation is listed as NA and the model as single group.
The study evaluated ViviGen Cellular Bone Matrix in patients undergoing posterolateral lumbar fusion without interbody fusion. In the described study arm, one side of the fusion was coated with milled local autograft bone, while the opposite side received an equal volume of ViviGen. Although the sides allow an internal comparison in principle, the registry classifies the study as single-arm; it does not describe random assignment of material to side or a separate control group.
The primary outcome concerned surgical levels with successful lumbar fusion, with assessment at 12 months prospective from surgery. The study summary says subjects were to be followed to 24 months for final assessment. Listed secondary outcomes were changes in Visual Analog Scale pain scores and the Oswestry Disability Index, version 2.1a. The registry record lists three outcome measures, but detailed results and analyses are not reported in the registry record.
The study status is terminated. That status does not, by itself, explain why enrollment or follow-up ended, whether all planned assessments were completed, or whether the termination changed the analysis plan. Those details are not reported in the registry record. The posted record also does not report a statistical analysis plan or the results needed to estimate fusion outcomes.
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 | Left Side - Local Autograft Bone | Right Side - ViviGen |
|---|---|---|
| STARTED | 21 | 21 |
| COMPLETED | 20 | 20 |
| NOT COMPLETED | 1 | 1 |
Reasons for not completing this period:
| Reason | Left Side - Local Autograft Bone | Right Side - ViviGen |
|---|---|---|
| Lost to Follow-up | 1 | 1 |
Analysis population for the primary outcome, as defined in the registry: Surgical Levels have two sides being evaluated: 55 levels times 2: (Left- Autograft and Right - ViviGen)
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 | Study Arm |
|---|---|---|
| Participants analysed | 21 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 5 |
| Age, Categorical: >=65 years | Participants | 16 |
| Age, Continuous | years | 70.95 (SD 9.34) |
| Sex: Female, Male: Female | Participants | 9 |
| Sex: Female, Male: Male | Participants | 12 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 21 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 2 |
| Race (NIH/OMB): White | Participants | 18 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 |
| Region of Enrollment: United States | participants | 21 |
6. Primary Endpoint
The registry lists the primary outcome as The Number of Surgical Levels With Successful Lumbar Fusion, measured over 12 months prospective from surgery.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Surgical Levels |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of surgical levels with successful lumbar fusion. It is a count endpoint: the recorded quantity is how many assessed surgical levels fall into the success category, rather than a continuous measurement such as a pain score. The registry defines fusion extent using the Lenke classification. Grade A counts as radiographic success, grade B as partial success, and grades C and D as radiographic failure.
Fusion is a structural outcome relevant to the procedure being studied. Classifying radiographic findings gives the study a defined way to distinguish complete success from partial success and failure. The registry specifies assessment at 12 months prospective from surgery. Its endpoint population description refers to surgical levels having two sides evaluated, with local autograft on the left and ViviGen on the right, and states “55 levels times 2.” This description does not supply the observed number of successful levels or category-specific findings.
Because the endpoint is a count of levels and the record describes paired sides within a single-arm study, interpretation would depend on how levels and sides were analyzed and how observations within a participant were handled. Those analysis details, including the endpoint results, are not reported in the registry record. No conclusion about the observed fusion outcome can be drawn from the endpoint definition alone.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes the question and measurement approach, but it does not provide numerical primary endpoint results. It identifies the Lenke categories and defines radiographic success, partial success and failure, yet gives no observed counts for those categories. It also lists zero analyses. As a result, the posted record does not establish how many levels met the success definition or how fusion findings differed between the side receiving ViviGen and the side receiving local autograft.
The one-arm structure matters. The study description assigns materials to opposite sides of a fusion, so the design has a potential within-operation comparison. That does not make it a randomized two-arm trial: allocation is recorded as NA, masking as none, and the model as single group. The registry record does not report randomization of material to side, a prespecified paired analysis, or a statistical estimate of the side-to-side contrast. Without those details and results, a comparative effect cannot be interpreted.
The primary assessment is specified at 12 months prospective from surgery. The summary also says follow-up was planned through 24 months for final assessment, but no 24-month results are included in the posted record. The status is terminated; the record does not explain the reason, report the completeness of follow-up, or state how termination affected the intended outcomes. The enrollment entry is 21, but the record does not provide an analysis population or participant-level disposition.
The registry lists Visual Analog Scale pain-score changes and the Oswestry Disability Index as secondary outcomes. It does not provide their numerical results, definitions of clinically meaningful change, or analyses. Thus, the existence of named outcomes should not be mistaken for evidence about their observed values.
Safety information is presented as counts of participants affected by serious and other adverse events, along with deaths and selected serious-event terms. These counts describe what is recorded, but the record does not provide event timing, attribution, severity grading beyond the serious-event classification, or a comparison group. The counts therefore cannot establish whether an event was caused by ViviGen or how safety compares with another treatment.
Overall, the registry record is informative about the intended study design, outcomes and selected safety counts, but not about the primary efficacy result. Any quantitative conclusion about fusion or comparative performance would require results and analysis details that are not reported in the registry record.
9. Statistical Methods Explained
Statistical interpretation depends first on the type of outcome and on how observations relate to one another. The primary outcome is a count of surgical levels classified by radiographic fusion status. It is not a continuous mean. In general, a count analysis describes the number of events or classifications observed within a defined unit of observation, such as a participant or surgical level. The appropriate analysis also depends on whether the unit-level observations are independent or clustered within participants.
What does the count endpoint represent?
The registry defines successful fusion as Lenke grade A, partial success as grade B, and failure as grades C and D. These categories have an ordered clinical interpretation, but the listed primary endpoint is the number of surgical levels with successful fusion. The description separately identifies partial success and failure; the record does not state whether the main analysis would treat these as separate categories, combine categories, or use another model. No observed category counts or analysis are reported.
In general, count outcomes may be analyzed with methods that model the expected count, while accounting for the amount of opportunity to observe a count. If observations vary more than a chosen model expects, over-dispersion can make standard errors too small when ignored. Over-dispersion means that the observed variability exceeds the model’s assumed variability. It is a general consideration, not a reported feature of this study: the registry record does not identify a count model, report a dispersion estimate, or provide data with which to assess it.
Why does the within-operation structure matter?
The study description places local autograft on one side and ViviGen on the opposite side of a fusion. General statistical reasoning treats paired or clustered observations differently from independent observations. Two sides from the same operation may share participant characteristics and surgical conditions; treating them as independent can misstate uncertainty if that dependence is ignored. A paired analysis can account for within-participant linkage, but its form depends on the endpoint and the prespecified analysis. The registry record does not report whether a paired method was planned or used, how multiple levels within a participant were handled, or whether material assignment to side was randomized.
Masking is recorded as none, and allocation is NA. Those entries describe the registry fields but do not fully explain how radiographs were assessed, whether assessors knew the material used on each side, or how disagreements were resolved. Such assessment procedures are not reported in the registry record. In general, blinded outcome assessment can reduce the risk that knowledge of treatment influences classification, although it cannot address all sources of bias.
What can a confidence interval tell a reader?
In general, a confidence interval expresses uncertainty around an estimated quantity under the assumptions of the analysis. A narrower interval indicates greater precision, while a wider interval indicates less precision. It does not guarantee that the model is appropriate or eliminate bias in measurement, allocation or follow-up. No confidence interval, effect estimate or inferential test for the primary outcome is reported in the registry record, so precision cannot be evaluated from the posted results.
The study’s single-arm designation also limits what a conventional between-group estimate would mean. The two sides may permit a within-operation contrast, but interpretation requires a defined unit of analysis and a method that accounts for pairing and any repeated levels. The record gives no contrast estimate or test. General concepts such as statistical significance cannot fill that gap: without an estimate and its uncertainty, there is no reported primary comparison to interpret.
How should planning calculations be read?
General sample-size planning asks how much information a future study might need to detect a specified effect under stated assumptions. The planning description associated with this record specifies a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Such calculations are planning illustrations, not observed power, and they are not evidence that the trial was designed or conducted with those assumptions.
The planning description says time-to-event calculations give total events and other calculations give participants per arm. These are general interpretation notes for planning outputs, not a statement that the actual study had two randomized arms. The registry record does not report its own sample-size justification or statistical plan. Since the primary observed effect and corresponding result are not reported, the meaning of any effect-based planning illustration cannot be assessed from the record alone.
Finally, a model’s assumptions should be read alongside the design and data. A prespecified analysis, a clear definition of the analysis population, and appropriate handling of missing or correlated observations support reproducibility. Those details are not reported in the registry record. Consequently, the statistical methods actually used, their assumptions, and the robustness of any result cannot be evaluated.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary fusion outcome and secondary outcomes concerning Visual Analog Scale pain-score changes and the Oswestry Disability Index, version 2.1a. It records three outcome measures, but does not report a multiplicity strategy, such as a hierarchy of tests or an adjustment for examining multiple outcomes. Without that information, the record does not show how the chance of false-positive findings across several analyses was to be controlled. No outcome analyses are listed.
Missing-data handling is not reported in the registry record. The enrollment entry is 21, but there is no participant flow, follow-up completeness, analysis population, or account of missing radiographs or questionnaire measurements. The study summary describes planned follow-up through 24 months, while the primary endpoint is specified at 12 months; observed completion at either time is not reported. It is therefore not possible to determine whether missingness could have affected the fusion classifications or secondary outcomes.
The registry also does not report an intention-to-treat, per-protocol, or other analysis population. In general, analysis-population definitions matter because exclusions after enrollment can change which participants contribute to an estimate. For the side-to-side fusion description, it would also matter how incomplete paired observations or participants with multiple assessed levels were treated. No such rules are reported.
The record’s terminated status does not explain whether missing data or termination influenced the analyses. Reasons for termination and any amendments to planned analyses are not reported in the registry record. These omissions prevent assessment of the extent to which the posted outcome set, analysis choices and follow-up correspond to the original plan.
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 |
|---|---|---|---|
| Study Arm | 6 | 21 | 28.6% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Study Arm | 0 of 21 |
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 |
|---|---|
| Study Arm | 14 of 21 |
Most frequent serious adverse event terms
| Event term | Organ system | Study Arm |
|---|---|---|
| Alcohol Withdrawal | General disorders | 1 of 21 |
| Shoulder Surgeries | Surgical and medical procedures | 1 of 21 |
| Altered Mental State | Psychiatric disorders | 1 of 21 |
| Atrial Fibrillation (AFib) With Rapid Ventricular Response (RVR) | Cardiac disorders | 1 of 21 |
| Hip Arthroplasties | Surgical and medical procedures | 1 of 21 |
| Wound Dehiscence | Infections and infestations | 1 of 21 |
| Urinary Tract Infection | Renal and urinary disorders | 1 of 21 |
| subdural hematoma | Injury, poisoning and procedural complications | 1 of 21 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Study Arm |
|---|---|---|
| Increased Paresthesia or Weakness | Nervous system disorders | 5 of 21 |
| Worsened Back and/or Leg Pain | Musculoskeletal and connective tissue disorders | 3 of 21 |
| Epigastric or Abdominal Pain | Gastrointestinal disorders | 3 of 21 |
| Urinary Tract Infection | Renal and urinary disorders | 1 of 21 |
| Neck Pain | Musculoskeletal and connective tissue disorders | 1 of 21 |
| Ileus | Gastrointestinal disorders | 1 of 21 |
| Falls or injury | General disorders | 1 of 21 |
| Viral Infections | Infections and infestations | 1 of 21 |
| Shoulder Pain | Musculoskeletal and connective tissue disorders | 1 of 21 |
| Basal Cell Carcinoma | Skin and subcutaneous tissue disorders | 1 of 21 |
Serious events with the highest arm-level rate: alcohol withdrawal (4.8%), shoulder surgeries (4.8%), altered mental state (4.8%), atrial fibrillation (afib) with rapid ventricular response (rvr) (4.8%), hip arthroplasties (4.8%).
The registry reports 21 participants at risk for serious adverse events, with 6 affected, and 21 at risk for other adverse events, with 14 affected. It reports 0 deaths. These are participant counts as recorded in the safety entry; they do not provide event rates over a stated person-time period or show how many events each affected participant experienced.
The listed serious-event terms each have a recorded frequency of 4.8%: Alcohol Withdrawal, Shoulder Surgeries, Altered Mental State, Atrial Fibrillation (AFib) With Rapid Ventricular Response (RVR), Hip Arthroplasties and Wound Dehiscence. The registry record does not report timing, severity details beyond the serious-event listing, or whether any event was judged related to the study intervention. The terms should therefore be read as recorded events, not as established effects of ViviGen.
There is no separate comparison group in this single-arm study, and the safety counts cannot show whether these figures are higher or lower than they would be under another treatment. The registry record also does not report a detailed adverse-event collection or adjudication method. These counts provide a limited description of reported safety information rather than a comparative safety estimate.
12. What the Result Does, and Does Not, Mean
The record establishes that a prospective, single-arm post-market study was intended to evaluate fusion in patients undergoing posterolateral lumbar surgery using ViviGen Cellular Bone Matrix. It defines the radiographic categories for the primary endpoint and describes an arrangement in which local autograft and ViviGen were applied to opposite sides. It also records selected adverse-event counts and planned follow-up.
It does not establish the observed primary fusion result. The registry gives no counts of successful, partially successful or failed levels, no comparative estimate between sides, and no uncertainty interval or statistical test. A treatment effect cannot be inferred from the endpoint definition or from the fact that the sides were assigned different materials. The registry record does not report the analysis needed to interpret that within-operation comparison.
The secondary outcomes are named but their results are not reported. The record therefore does not establish changes in pain scores or disability, nor does it permit a comparison of those outcomes with another treatment. Similarly, safety counts describe reported participants affected but do not establish causation, comparative risk or the clinical significance of individual events.
The status of terminated indicates the registry’s recorded study status, but does not explain why the study ended or how much follow-up was completed. It should not be treated as evidence that the intervention succeeded or failed. In general, a study’s interpretation depends on observed results, uncertainty, outcome ascertainment and the analysis population, not on its status label alone.
The most defensible reading is therefore descriptive: the record documents the planned clinical question, a single-arm design with opposite-side materials, the fusion classification and selected safety counts. It does not support a conclusion about the comparative effectiveness or safety of ViviGen from the posted results.
13. Why This Trial Matters Statistically
This study is statistically notable because it combines a single-arm registry classification with an internal comparison of opposite sides of a fusion. Such a design raises an important distinction between the number of treatment groups and the number of observations. A study may collect measurements on two sides while still lacking independent randomized groups. Correct interpretation depends on recognizing pairing and the possibility that levels within the same participant are related.
The endpoint is also a count of surgical levels, while the study describes follow-up of participants. The unit used for analysis matters: a level-based count and a participant-based outcome answer different questions. If several levels belong to one participant, their results may not be statistically independent. The registry record does not report the analysis method or how this structure was handled, making it impossible to assess the precision of any treatment contrast.
Another statistical issue is the distinction between defining an outcome and reporting its result. The Lenke categories provide an operational definition, but they do not tell readers how many levels were classified in each category. This record illustrates why an outcome description alone is not enough for evidence assessment: estimates, uncertainty, analysis methods and completeness of follow-up are also needed.
Finally, the record includes safety counts without comparative data or attribution information. Counts can describe what was recorded, but they cannot by themselves isolate intervention-related risk. For clinical researchers, separating descriptive registry information from inferential evidence is central to avoiding conclusions that the available analysis cannot support.
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 main limitation for interpretation is that primary outcome results are not reported in the registry record. Although the endpoint and its classification rules are defined, there are no observed counts, effect estimates, confidence intervals or tests. The record lists zero analyses, leaving no statistical result to evaluate.
The design is recorded as single-group, with allocation NA and no masking. The study description assigns different materials to opposite sides, but does not report whether side assignment was randomized or how dependence between sides and levels was analyzed. The endpoint population description states “55 levels times 2,” but does not explain how those observations relate to the enrollment entry of 21 or how they entered an analysis. These details are not reported in the registry record.
The record names secondary outcomes but does not provide their results, assessment schedules or analysis details. It does not report missing-data methods, analysis populations, follow-up completeness, radiograph assessment procedures, or the reason for termination. While follow-up through 24 months is described as planned, the posted record does not provide final follow-up findings.
Safety information is limited to participant counts, deaths and selected serious-event terms. Event timing, intervention attribution, person-time, collection procedures and comparative safety findings are not reported. The absence of those details limits interpretation of both the event counts and the relationship of events to treatment.
These limitations reflect what is available in the registry record; they do not establish that unreported methods or results were absent from other records.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Single-Armed Use of ViviGen Cellular Bone Matrix in Patients Undergoing Posterolateral Lumbar Surgery — NCT04007094.
- Registry record last updated 2024-01-24; status last verified 2023-05.
- Results first posted 2024-01-24.
- 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
The registry record describes NCT04007094, a prospective, single-arm post-market study of ViviGen Cellular Bone Matrix in posterolateral lumbar fusion without interbody fusion. Ohio State University is listed as sponsor. The recorded status is terminated, enrollment is 21, and phase is NA. The study start date is 2019-02-12, with primary completion recorded as 2022-01-21.
The primary outcome is the number of surgical levels with successful lumbar fusion at 12 months, classified using Lenke grades. The study description places local autograft on one side and ViviGen on the opposite side. Pain-score changes and the Oswestry Disability Index are listed as secondary outcomes, and follow-up through 24 months is described in the study summary.
The record reports serious and other adverse-event counts and 0 deaths, but lists zero analyses. Primary and secondary outcome results, statistical methods, missing-data handling and the reason for termination are not reported in the registry record. Accordingly, the posted information describes the study framework and selected safety counts, but does not provide an interpretable efficacy analysis.