High-Purity Type I Collagen Nerve Wrapping in Peripheral Nerve Procedures: A Prospective Registry: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for High-Purity Type I Collagen Nerve Wrapping in Peripheral Nerve Procedures: A Prospective Registry (NCT07360730), a na na study. The primary outcome is Motor Functional Recovery (MRC Grade ≥ M3).

2. Clinical Question

The registry is prospective and observational. Its stated focus is early clinical outcomes after HPTC wrapping in the setting of peripheral nerve procedures, rather than a randomized estimate of the effect of the wrap against an untreated or alternative-treatment group. Consequently, the primary endpoint is a count of participants reaching a specified motor grade; it is not, by itself, a comparison of outcomes between treatment strategies.

The registry also names sensory recovery, neuropathic pain, patient-reported function, complications, and satisfaction as outcomes of interest. QuickDASH is listed for upper-limb function and LEFS for lower-limb function. These outcome domains can describe different aspects of recovery, but their presence in the registry does not establish that results for them are available. The registry record does not report the primary motor recovery count or an analysis comparing outcomes across groups.

3. Trial Design

This is a prospective multicentre observational registry of HPTC nerve wrapping in peripheral nerve procedures. It is listed as a single-group study, with one HPTC Nerve Wrap Arm. Participants in that arm undergo procedures such as nerve repair, coaptation, grafting, nerve transfer, or decompression, with the HPTC membrane used as a circumferential wrap during the procedure.

The registry lists an enrollment of 40 and a study status of COMPLETED. The recorded study start is 2025-12-09, and the primary completion date is 2026-02-26. These registry entries describe enrollment and administrative status; they do not establish that each outcome was observed or analyzed. The record does not report the number of participants with an available assessment at each follow-up time.

Allocation is listed as NA, masking as NONE, and phase as NA. There is no randomized allocation described and no separate control arm. The record therefore supports description of outcomes among participants receiving the wrap, but not a controlled causal comparison with another procedure or no wrap. Differences in the procedures represented, underlying nerve conditions, and clinical circumstances could matter when interpreting outcomes, but the registry record does not provide the details needed to characterize or adjust for such differences.

The primary outcome is motor functional recovery at two months post-operative. The registry describes secondary outcomes relating to sensory recovery, neuropathic pain, functional status, complications, and patient satisfaction, with assessments planned at standardized postoperative intervals up to two months. The record lists seven outcome measures but reports zero analyses. Statistical analysis methods, analysis populations, and participant flow by outcome are not reported in 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

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.

6. Primary Endpoint

The registry lists the primary outcome as Motor Functional Recovery (MRC Grade ≥ M3), measured over 2 months post-operative.

The primary endpoint is the count of participants whose involved muscle groups reach MRC grade M3 or higher at two months post-operative. The Medical Research Council motor grading system is used to assess motor function. In the registry definition, the threshold represents active movement against gravity.

A threshold endpoint turns a graded clinical assessment into a clear status: whether a participant has reached the specified level of motor recovery by the stated assessment time. This can be useful for describing early recovery in a registry where participants undergo varied peripheral nerve procedures. It also makes the outcome readily interpretable in terms of how many participants reach the defined milestone.

That simplification has a trade-off. A threshold count does not show the full distribution of motor grades, changes from baseline, or the amount of recovery among participants who remain below the threshold. The registry record does not report baseline motor grades, the observed number meeting the threshold, or the analysis used for this endpoint. Thus, the endpoint definition is available, but its observed result and precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with the design and the form of the endpoint. This registry has one study group and is observational. It describes outcomes after HPTC wrapping, rather than estimating a contrast between randomly allocated groups. The distinction determines what the data can answer: a group-level outcome count can describe experience in the registry, whereas a causal treatment effect ordinarily requires a credible comparison and assumptions that address differences between groups.

What does a count endpoint convey?

The primary outcome is a count of participants who reach MRC grade M3 or higher at two months post-operative. The registry’s threshold corresponds to active movement against gravity. A count can communicate how many assessed participants met that threshold, but meaningful interpretation also requires a denominator: the number assessed or otherwise included in the analysis. A proportion would additionally depend on consistent outcome ascertainment and a clear definition of the analysis population. The registry record does not report the primary count, an assessment denominator, or an analysis population for this outcome.

A threshold can make a clinical endpoint easier to classify, but it discards information contained in the underlying grades. Two participants on opposite sides of the threshold may have similar grades, while participants on the same side may differ substantially. If baseline grades and follow-up grades were available, changes and distributions could offer complementary descriptions. Those data are not reported in the registry record. This is a general consideration about dichotomizing a graded measure, not a claim about the observed participants.

Why does a single-group design limit inference?

In a single-group observational registry, outcomes are recorded among participants receiving the intervention in the context of their clinical procedures. A result in that group can describe what was observed, but it cannot isolate the contribution of the wrap from other aspects of care, the procedure performed, the underlying condition, or the natural course of recovery. This is a general limitation of uncontrolled observational evidence. A matched or adjusted comparison could address some sources of imbalance in some settings, but no such comparison or adjustment is reported in the registry record.

The record describes masking as NONE and allocation as NA. These entries do not establish how outcome assessment was conducted or whether assessors knew the treatment details; assessor procedures are not reported in the registry record. For an outcome that involves clinical grading, the assessment process and consistency matter. The registry record does not describe assessor training, repeat ratings, or reliability procedures, so these features cannot be evaluated.

How should precision be assessed?

A confidence interval is a general statistical tool for expressing the uncertainty around an estimated quantity. For a count endpoint converted to a proportion, an interval would describe the precision of the estimated proportion, subject to the method and assumptions used. No confidence interval or primary outcome estimate is reported in the registry record. Therefore, neither the observed level of motor recovery nor the uncertainty around it can be judged from the recorded information.

For binary outcomes, the precision of an estimate depends in part on how many participants contribute outcome information and on the observed event pattern. A planned enrollment figure is not a substitute for a reported outcome denominator. The registry lists enrollment of 40, but does not state how many participants had evaluable primary outcome data. The outcome count and missing assessments are not reported.

General statistical methods also need to match the data structure. If participants contribute repeated assessments, observations within a participant are related rather than independent; methods may need to account for that dependence. If outcome counts are compared across groups, the design and the number of events influence which estimates are informative. These are general methodological considerations. The registry record does not report repeated-measures models, a between-group analysis, or any other clinical outcome analysis.

What do planning assumptions mean?

The registry’s planning note describes an illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes detecting a stated fraction of the observed effect. These assumptions describe a planning calculation, not the design actually recorded: this registry is single-group, with no randomized two-arm comparison. Any sample-size illustration is a planning aid, not observed power and not evidence that an effect was detected. The registry record does not report the clinical outcome result needed to evaluate the stated observed effect in context.

In general, power is a design-stage probability calculated under specified assumptions about an effect, variability, significance threshold, and analysis. It does not describe the probability that a reported result is true. A post hoc calculation based on an estimated effect cannot repair an uncontrolled design or resolve uncertainty caused by missing outcomes. The record does not report a trial-specific sample-size justification or a statistical analysis plan.

Why can over-dispersion matter?

Over-dispersion is a general concern for count data when observed variability is greater than a simple model assumes. If a count outcome were modeled with a distribution that assumes a particular mean-variance relationship, unaccounted extra variability could make uncertainty appear too small. The primary endpoint in this registry is described as a count of participants meeting a binary threshold, not as a recurrent-event count. No count regression model or dispersion assessment is reported, so over-dispersion is not an established feature of these data. This concept is included as a general explanation, not as a description of an analysis performed in the registry.

Because no outcome analyses are listed, the statistical methods used to summarize the primary endpoint and secondary outcomes are not reported in the registry record. The available information defines the question and several design features, but does not permit an independent assessment of model choice, estimate precision, or robustness.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("HPTC Nerve Wrap Arm")
n      <- c(40)
events <- c(34)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  HPTC Nerve Wrap Arm  40  34  85.0  70.2  94.3  70.9  92.9  70.8  92.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists seven outcome measures, including the primary motor recovery endpoint and secondary domains such as neuropathic pain, functional outcomes, and satisfaction. When multiple outcomes are examined, the chance of at least one apparently notable result can increase if each is tested separately without a plan for multiplicity. This is a general statistical concern, not a claim that such testing occurred in this registry.

A prespecified hierarchy, adjustment method, or explanation of which outcomes are confirmatory would help readers interpret multiple findings. The registry record does not report a multiplicity strategy, a statistical analysis plan, or any clinical outcome analyses. It is therefore not possible to tell whether outcomes were analyzed as a family, treated as exploratory, or handled in another way.

Missing outcome data also affect interpretation. The enrollment is listed as 40, but the registry does not report how many participants completed each assessment, why observations might be missing, or how missing values were handled. The primary outcome denominator and analysis population are not reported in the registry record. Without those details, the extent and potential influence of missingness cannot be assessed.

The record does not state whether all enrolled participants were included in each outcome summary, whether participants were excluded after enrollment, or how procedure-specific outcomes were grouped. These analysis population details are not reported in the registry record. The administrative status COMPLETED does not by itself establish complete follow-up or complete outcome data.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

For the HPTC Nerve Wrap Arm, the registry lists 40 at risk for serious adverse events and zero affected. It lists 40 at risk for other adverse events and 2 affected. Deaths are listed as zero. These are counts as recorded; no rates or comparative estimates are reported.

The record lists no top serious adverse event terms. It does not report further event descriptions, timing, severity details beyond the serious-versus-other categories, relatedness assessments, or how adverse events were collected. The meaning of “other” should therefore be read as the registry’s category, not as a detailed clinical description of the events.

A zero serious-event count in a registry does not establish that serious harms are impossible or that the intervention is safer than an alternative. The study has no separate control group, and these counts alone do not quantify risk relative to another procedure. The at-risk count is not a substitute for information about follow-up completeness or duration. Safety interpretation should remain limited to the adverse-event counts and categories recorded in the registry.

13. What the Result Does, and Does Not, Mean

The registry record establishes that HPTC nerve wrapping was evaluated prospectively in a multicentre observational setting and identifies the intended primary outcome: achievement of MRC grade M3 or higher at two months post-operative. It also documents a single HPTC Nerve Wrap Arm and lists secondary outcome domains. These details clarify what the registry was designed to describe.

The record does not report the primary motor recovery result. It therefore does not show how many participants achieved the defined motor threshold, how complete the outcome data were, or how precisely any estimate can be stated. Secondary clinical outcomes and analyses are also not reported in the registry record. The absence of a reported estimate should not be interpreted as evidence of either benefit or lack of benefit.

Even a reported outcome count from this single-group registry would not, by itself, demonstrate that the wrap caused the outcome. There is no separate control group and no randomized comparison. Recovery may be related to the underlying nerve condition, the procedure, participant characteristics, and other care. The registry record does not provide a comparative design or analysis that would distinguish these influences.

The safety entries are limited descriptive counts: zero serious adverse events affected, 2 other adverse events affected, and zero deaths in the HPTC Nerve Wrap Arm. They do not provide a comparison with another treatment or a complete characterization of event types and follow-up. The proper scope of interpretation is therefore the recorded counts, not a broad claim about safety.

Overall, the study question and endpoint definition are clear enough to identify the intended early motor outcome, but the registry record does not include the clinical outcome findings needed to assess that outcome. Any conclusions about recovery, patient-reported function, or comparative safety would go beyond the reported information.

14. Why This Trial Matters Statistically

This registry addresses a statistical question that arises often in procedural research: how to describe early outcomes when patients receive an intervention as part of varied clinical procedures and there is no randomized control group. A prospective registry can define outcome collection and record experience in a clinical setting. Its interpretation still depends on transparent reporting of who was assessed, what outcomes were observed, and how those outcomes were summarized.

The primary endpoint uses a threshold on a recognized motor grading system. That makes the intended outcome understandable, while raising familiar statistical issues about losing information when a graded measure is reduced to a threshold count. A count without its denominator, baseline context, and uncertainty estimate is difficult to assess. The registry record identifies the endpoint definition but does not report these outcome details.

The study also names distinct outcome domains, including pain, sensory recovery, function, satisfaction, and complications. Considering more than one domain may give a broader picture of early clinical experience, but it makes prespecification and clear reporting important. The registry lists seven outcome measures and zero analyses, so readers cannot evaluate how those outcomes were analyzed or whether results were complete.

Finally, the single-group observational design highlights the difference between describing outcomes and estimating an intervention effect. Counts in an intervention group can be useful for characterization, but comparison is needed to separate outcomes associated with the intervention from other influences. The record’s design and reporting gaps are therefore central to statistical interpretation, not merely technical details.

15. 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 trial-specific limitation is the absence of reported clinical outcome results. Although the primary endpoint is defined at two months post-operative, the number meeting the MRC threshold and the denominator assessed are not reported in the registry record. Without these, readers cannot judge the observed motor recovery level or its precision.

The registry is single-group and observational. It does not include a separate control arm or randomized allocation, so it cannot provide a direct comparison with another procedure or with no wrap. The range of eligible procedures and listed conditions may also represent clinically varied participants. The registry record does not report case-mix details or analyses that would clarify variation in outcomes across these groups.

Outcome ascertainment details are limited. The record does not report baseline motor status, the distribution of MRC grades, the number assessed at each follow-up, or the handling of missing assessments. It describes standardized postoperative intervals up to two months but does not provide assessment-level completion information. The COMPLETED status should not be interpreted as proof of complete outcome follow-up.

The record lists seven outcome measures but zero analyses. It does not report a statistical analysis plan, methods for addressing multiple outcomes, or analysis populations. For the safety entries, serious-event terms are not listed, and further details about the other events and ascertainment procedures are not reported. These limitations restrict assessment of both clinical outcomes and safety beyond the recorded counts.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: High-Purity Type I Collagen Nerve Wrapping in Peripheral Nerve Procedures: A Prospective Registry — NCT07360730.
• Registry record last updated 2026-03-30; status last verified 2026-03.
• Results first posted 2026-03-30.
• 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.

19. Record Summary

NCT07360730 is a prospective multicentre observational registry of High-Purity Type I Collagen nerve wrapping during peripheral nerve procedures. It is listed as a single-group study with enrollment of 40, status COMPLETED, a start date of 2025-12-09, and a primary completion date of 2026-02-26.

The primary outcome is the count of participants achieving MRC grade M3 or higher in involved muscle groups at two months post-operative. Secondary domains include neuropathic pain, upper- and lower-limb patient-reported function, and satisfaction. The registry record does not report the primary outcome result or clinical outcome analyses.

Safety entries list zero serious adverse events affected, 2 other adverse events affected, and zero deaths in the HPTC Nerve Wrap Arm. With no separate comparator and no reported clinical outcome analyses, the record supports description of the study design and registered outcomes, but not a comparative estimate of clinical effect.