N-Force Screws Augmented With N-Force Blue in Hip Fractures: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for N-Force Screws Augmented With N-Force Blue in Hip Fractures (NCT03807349), a na na study. The primary outcome is Number of Participants With a Reoperation.

2. Clinical Question

The clinical question is descriptive rather than comparative. The study concerns use of an augmented screw device in a specified fracture setting, and its primary endpoint focuses on whether a participant undergoes another operation during follow-up. Reoperation is clinically consequential, but the registry’s stated endpoint definition includes several possible reasons for surgery. It does not identify which reason, if any, applied to a participant in the posted primary outcome result, because that result is not reported in the registry record.

The study’s stated objective was to confirm safety and performance. Those aims can involve different kinds of evidence: a count of reoperations, radiographic healing, functional measures, quality-of-life measures, and adverse events. The registry lists several secondary outcomes in addition to reoperation, but their numerical results are not included in the registry record for this analysis. Without a reported primary result or comparator, the clinical question cannot be answered with an estimate of treatment effect against another approach.

3. Trial Design

The registry describes a prospective study of N-Force Screws augmented with N-Force Blue for intracapsular proximal femur fracture treatment. The listed enrollment is 12, the model is single group, and the intervention is a device. The study is not recorded as randomized: allocation is NA. Masking is listed as NONE. These design features mean that the posted record describes an evaluation of participants receiving the device, not a randomized comparison between treatment groups.

The listed conditions include intracapsular proximal femur fracture and Garden Grade I and Garden Grade II subcapital fracture of the femoral neck. The arm description identifies N-Force Screws augmented with N-Force Blue in intracapsular femur fractures. The record states that the study was intended to confirm safety and performance. It does not report a separate control group, an allocation process, or a masking procedure.

The registry lists a study start date of 2019-02-21 and a primary completion date of 2021-03-11. Its status is TERMINATED. The reason for termination is not reported in the registry record, so the status alone does not establish why the study ended or whether the planned follow-up and analyses were completed.

The primary endpoint is the number of participants with a reoperation, with a stated timeframe of 12 months. The listed secondary outcomes cover radiographic fracture healing, participant classification at 12 months, clinical healing and function, quality of life, mobility testing, and cost-effectiveness. The registry lists 9 outcome measures, while the number of analyses is 0. A count of outcome measures describes what was registered, not how many results were reported. The primary result, results for the listed secondary outcomes, and further details about analysis populations are not reported in the registry record.

Because the study has one group and no recorded randomized comparator, estimates from the study can describe observed outcomes among participants in that group, if reported. They cannot by themselves distinguish an intervention effect from other explanations, such as the natural course of fracture recovery or differences in participant characteristics. The record does not report the protocol details or statistical plan needed to assess how the study was intended to address those issues.

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

Reasons for not completing this period:

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 Number of Participants With a Reoperation, measured over 12 months.

The primary endpoint is the number of participants with a reoperation within 12 months. The registry defines a reoperation as an operation after the initial surgery undertaken to promote fracture healing, relieve pain, treat infection, or improve function. This is a participant-level count outcome: it concerns whether participants experienced the specified event, rather than a continuous measurement such as a score or test time.

Reoperation is used as an endpoint because it captures a consequential event that may reflect a need for further surgical care after the initial procedure. Its definition is broad, however. The stated reasons include healing, pain, infection, and function, which are clinically different circumstances. A total count without further detail would not show which reason prompted each reoperation, how many operations a participant had, or when within follow-up the event occurred. Those details are not reported in the registry record.

The registry identifies the outcome and timeframe but does not report the primary endpoint result. It is therefore not possible to describe the observed reoperation frequency, assess its precision, or determine how the result varied across reasons for surgery from the available record. No confidence interval or analysis estimate for this endpoint is reported in the registry record.

In general, a confidence interval around a participant-level event estimate communicates the range of values compatible with the data and the chosen method. It helps distinguish a precise estimate from one that remains uncertain. That general interpretation cannot be applied to this primary endpoint without a reported result and uncertainty estimate. The endpoint definition alone indicates what was intended to be counted; it does not establish how many participants had a reoperation.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count mean?

The primary endpoint is a count of participants who had a reoperation within 12 months. For a binary event outcome, each participant is classified according to whether the defined event occurred during the stated follow-up period. The resulting count can be interpreted only alongside its denominator and the rules used to determine event status. The registry record does not report the primary count, denominator used in an analysis, or an uncertainty estimate for this endpoint.

In general, a proportion describes the share of an analyzed group with the event. A confidence interval expresses uncertainty around an estimate, using a specified statistical method. With limited observations, an interval can be wide, indicating that many underlying event rates remain compatible with the data. These are general concepts; no primary endpoint estimate or confidence interval is reported in the registry record.

What does the single-group design allow?

The study is identified as single group, with allocation listed as NA and masking as NONE. A single-group analysis can describe outcomes among participants who received the intervention. It cannot directly estimate a difference between the intervention and a concurrent control group when no such group is recorded. Comparisons with external experience, historical data, or another study would require additional information and assumptions; none are described in the registry record.

Randomization is a general design method that assigns participants to groups in a way intended to balance measured and unmeasured characteristics on average. Since this study is not recorded as randomized and has no listed comparator, a randomized treatment-effect interpretation is not appropriate. Lack of masking can also matter in general when outcomes involve judgment or participant reporting, because knowledge of treatment may influence assessment or reporting. The registry does not report masking beyond NONE or explain how outcome assessments were conducted.

Why do event definitions and follow-up matter?

The endpoint definition groups reoperations undertaken for fracture healing, pain relief, infection treatment, or improved function. A broad event definition can capture a clinically important outcome, but it combines events with potentially different causes. In general, interpretation is clearer when event definitions, adjudication procedures, timing, and reasons are reported. Those details are not reported in the registry record beyond the stated definition and 12-month timeframe.

Follow-up also determines whether an event could be observed. A participant without a recorded reoperation might have completed follow-up without an event, or might have incomplete outcome information. These situations cannot be distinguished without follow-up and missing-data details. The registry does not report those details for the primary endpoint.

What can be learned from the safety counts?

The registry reports participant counts for serious and other adverse events, with 12 at risk in each category, as well as a death count. Participant counts indicate how many people were affected, not necessarily how many separate event episodes occurred. A participant may have more than one event, and a count of affected participants does not describe event duration, severity beyond the category, or causal attribution. The listed serious term and percentage are registry entries; no additional calculation is needed to interpret them.

In general, safety rates are most informative when definitions, exposure time, ascertainment methods, severity, and relatedness to the intervention are clear. A single-group safety count cannot establish whether the observed events occurred more or less often than they would with another treatment. The registry entries do not report an external comparison or a control group.

What does the statistical plan tell us?

The registry entries do not report a statistical analysis plan, a sample-size justification, interim analyses, or the methods used for the registered outcomes. The number of analyses is listed as 0, but the meaning of this registry entry is not explained in the available record. It should not be treated as evidence that no analysis was performed, nor as proof that analyses were completed. The methods and results are not reported in the registry record.

In general, a prespecified analysis plan helps readers understand which outcomes and comparisons were intended, how missing values were to be handled, and whether adjustments were planned for multiple outcomes. Without those details, the risk of selective emphasis and the suitability of any analysis cannot be assessed from the registry information. No sample-size illustration or observed-power interpretation can be derived from the reported details. Any planning calculation would be distinct from evidence about the trial’s observed outcomes.

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("N-Force Screws")
n      <- c(12)
events <- c(0)
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  N-Force Screws  12  0  0.0  0.0  26.5  0.0  24.2  0.2  24.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and several secondary outcomes spanning radiographic healing, classification, clinical healing, quality of life, mobility, and cost-effectiveness. Looking at multiple outcomes can create a multiplicity issue: in general, the more statistical tests considered, the greater the chance that at least one appears notable by chance if each is interpreted without accounting for the number of tests. Whether and how that concern applies depends on the planned analyses and the claims being made.

The statistical plan, any multiplicity adjustment, and any hierarchy among outcomes are not reported in the registry record. The number of analyses is listed as 0, but the record details do not explain that entry. No p-values or outcome-specific analysis results are reported in the registry record for this analysis, so there is no basis to assess significance testing or adjustment choices.

Missing-data handling and analysis populations are also not reported in the registry record. The enrollment figure does not establish how many participants had complete primary outcome follow-up or contributed to secondary outcomes. It is not possible to determine whether outcomes were analyzed in all enrolled participants, only those with available data, or another defined group.

In general, missing outcome data can affect estimates if participants with missing information differ systematically from those with observed information. A clear report would describe the extent and reasons for missingness, the analysis population, and any assumptions or sensitivity analyses. Those details are unavailable here, so the potential influence of missing data cannot be assessed.

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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: leg pain and failure to thrive (8.3%).

The registry reports 1 participant affected by serious adverse events among 12 at risk, 8 participants affected by other adverse events among 12 at risk, and 0 deaths in the listed N-Force Screws group. These are participant counts. They do not state how many separate event episodes occurred, whether an individual experienced more than one event, or when events happened.

The registry lists “Leg Pain and failure to thrive” as the top serious adverse event term and records 8.3% for that term. This is the term and percentage as entered in the record; it should not be interpreted as an independently recalculated estimate. The registry entries do not clarify whether the phrase combines separate event terms or provide additional event-level detail.

Adverse-event counts are descriptive in a single-group study. Without a control group, they cannot show whether an event was more or less frequent than under another treatment. The registry entries also do not report event attribution, exposure time, collection procedures, severity grading beyond the serious/other categories, or follow-up completeness. The listed counts therefore characterize reported safety observations but do not establish causation or a comparative safety profile.

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

The registry record identifies a prospective, single-group study of N-Force Screws augmented with N-Force Blue for intracapsular proximal femur fractures. It records an enrollment of 12 and a primary endpoint of reoperation within 12 months. It also reports participant counts for serious adverse events, other adverse events, and deaths. These details describe the study question, design, and some safety observations.

The primary reoperation result is not reported in the registry record. As a result, the posted information does not establish how many participants had a reoperation, how precise an estimate would be, or which stated reason for reoperation applied. Numerical results for the listed secondary outcomes are also not reported in the registry record for this analysis. The study’s stated aim to confirm safety and performance is an objective, not a finding.

The record does not include a comparator arm or randomized allocation. Therefore, the results cannot support a direct comparative estimate of the intervention against another treatment. In general, observed outcomes in a single group may reflect the intervention, participant characteristics, the course of the condition, or other factors. The design recorded cannot separate those explanations through a randomized comparison.

The status TERMINATED indicates the registry’s recorded status, but the reason for termination is not reported in the registry record. It does not, on its own, show whether the study ended because of safety, recruitment, feasibility, or any efficacy finding. The registry entries also do not establish completion of all planned follow-up or analyses.

These limitations do not erase the descriptive value of the registry entry. The record identifies the intended population, device, primary question, timeframe, and some safety counts. But the absence of the primary outcome result, secondary results, analysis details, and a control group prevents a quantitative assessment of reoperation outcomes or a conclusion about comparative effects. Any interpretation should remain within those boundaries.

14. Why This Trial Matters Statistically

This study illustrates why design and reporting details matter when interpreting clinical outcome statistics. A registered primary endpoint can be clearly defined—in this case, participants with a reoperation within 12 months—while still leaving the central clinical result unknown if the outcome count and its uncertainty are not reported. Knowing the question is not the same as knowing its answer.

The single-group design also defines what can be learned. A group’s observed outcomes can provide descriptive information, but a concurrent comparator is needed for a direct study-based comparison between treatment approaches. With allocation listed as NA and no comparator arm recorded, the study cannot isolate a comparative treatment effect through randomization. This is a design limitation, not a numerical result.

The record further demonstrates the difference between outcome registration and outcome reporting. It lists measures of healing, function, quality of life, mobility, and cost-effectiveness, yet numerical results for those measures are not reported in the registry record for this analysis. The registry lists 9 outcome measures and 0 analyses, but those entries do not supply an analysis plan or explain which outcomes were evaluated.

Safety information is also more useful when reported with context. Participant counts and a listed adverse-event term give a limited descriptive picture, but they do not provide event timing, attribution, or a comparator. In general, these contextual details help readers distinguish observed events from evidence about causation or relative risk.

For biostatisticians and clinical researchers, the key statistical lesson is to separate design, registered intent, observed data, and inference. The registry record contains some information in the first two categories and limited safety counts, but not the primary endpoint result or enough analysis detail to support a treatment-effect estimate. Making those distinctions explicit prevents absence of a reported result from being mistaken for evidence of no events or no effect.

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 study’s single-group structure is the main trial-specific limitation for comparative interpretation. Allocation is listed as NA, and no control arm is recorded. Outcomes can therefore be described for the studied group if results are available, but there is no randomized comparison to estimate how outcomes differ under another approach.

The enrollment is listed as 12, and the primary outcome result is not reported in the registry record. This leaves the central endpoint unquantified. The registry entries do not report how many participants completed the 12-month outcome assessment or contributed data to any analysis, so the enrolled group should not be assumed to be identical to every outcome-specific analysis population.

The record lists the status as TERMINATED but does not report the reason for termination. It also does not report whether the planned follow-up was completed, whether the study changed its planned outcomes, or whether any analyses were conducted beyond the registry entry. Those unknowns limit interpretation of the relationship between the registered objectives and the posted results.

The endpoint definition includes several reasons for reoperation, but no reason-specific outcome details are reported. The secondary outcomes are listed without numerical results in the registry record. In addition, the statistical plan, sample-size rationale, interim analyses, missing-data approach, and analysis populations are not reported in the registry record.

The safety record gives participant counts and a serious-event term, but does not provide event timing, attribution, detailed severity, exposure duration, or a comparison group. These limitations mean the safety data are descriptive and cannot establish whether events were caused by the device or differ from those under another treatment. The registry’s stated objective and study status do not resolve these uncertainties.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: N-Force Screws Augmented With N-Force Blue in Hip Fractures — NCT03807349.
• Registry record last updated 2022-06-08; status last verified 2022-05.
• Results first posted 2022-06-08.
• 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

The registry record describes a prospective, single-group device study of N-Force Screws augmented with N-Force Blue in intracapsular proximal femur fractures, including Garden Grade I and Garden Grade II subcapital femoral neck fractures. Enrollment is listed as 12; allocation is NA, masking is NONE, and status is TERMINATED. The listed start date is 2019-02-21, and primary completion is recorded as 2021-03-11.

The primary endpoint is the number of participants with a reoperation within 12 months after initial surgery, for healing, pain, infection, or function. Its result is not reported in the registry record. The registry lists 9 outcome measures and 0 analyses. The reason for termination, statistical plan, analysis populations, and missing-data handling are not reported in the registry record.

For safety, the record reports 1 participant with serious adverse events among 12 at risk, 8 with other adverse events among 12 at risk, and 0 deaths. It lists “Leg Pain and failure to thrive” at 8.3% as the top serious term. These single-group counts do not provide a comparative safety estimate.