TRIGEN SURESHOT™ Distal Targeting System Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for TRIGEN SURESHOT™ Distal Targeting System Study (NCT01327508), a randomized na study. The primary outcome is Radiation Exposure Measurement.

2. Clinical Question

3. Trial Design

This was a prospective, multi-center, randomized comparison with a parallel-group model. The two arms were TRIGEN SURESHOT Distal Targeting and Standard Nailing Instrumentation. The former used the targeting instrumentation to find screw holes; the standard arm used a free-hand technique with x-rays. The registry records no masking. It lists an enrollment of 60 and a status of terminated. The study start is recorded as 2011-04, and primary completion as 2013-01. A reason for termination is not reported in the registry record.

The trial's stated objective was to quantify radiation exposure for subjects and surgeons during intramedullary nailing of the femur. The primary outcome was titled Radiation Exposure Measurement and had an intraoperative timeframe. Its description names a whole-body badge and a TLD ring badge. The primary endpoint was subsequently voided because the dosimeters did not capture radiation dose as expected. The registry also lists Distal Locking Time as a secondary outcome, but outcome results are not reported in the registry record.

Random allocation is intended, in general, to make the treatment groups comparable with respect to measured and unmeasured characteristics on average. A parallel design assigns participants to a group for the comparison rather than describing a crossover. These design features alone do not guarantee that a comparison can be interpreted: the outcome must also be measured successfully, and the analysis must be reported. Here, the primary measurement problem prevents the intended radiation comparison from being evaluated using the posted record. Details of the randomization procedure, eligibility criteria, participant flow, and analysis populations 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

Analysis population for the primary outcome, as defined in the registry: Primary endpoint voided. Dosimeters did not capture radiation dose as expected.

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.

Population: Unilateral femoral shaft fracture requiring treatment with intramedullary nails, in which the use of sterotactic surgery may be appropriate.

6. Primary Endpoint

The registry lists the primary outcome as Radiation Exposure Measurement, measured over Intraoperative.

The primary endpoint was intraoperative radiation exposure. The study objective identifies exposure for both subjects and surgeons during femoral intramedullary nailing as the quantity of interest. The endpoint description names a whole-body badge and a TLD ring badge as measurement approaches. The unit and the specific parameter to be reported are not reported in the registry record.

Radiation exposure is relevant to this study question because comparing measured exposure between the instrumentation groups was the intended way to assess the targeting approaches. In general, a measurement endpoint needs a functioning measurement process: the instrument must capture the quantity of interest in a form that can be analyzed. The registry explicitly says the dosimeters did not capture radiation dose as expected and that the primary endpoint was voided. Accordingly, no usable primary exposure result or group comparison is reported. The endpoint’s stated purpose should not be confused with an observed finding; the posted record does not establish the amount of exposure in either group.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, parallel-group comparison without masking. It also reports that the primary radiation endpoint was voided because the dosimeters did not capture dose as expected, and lists no analyses. The general concepts below help distinguish study design, measurement, and statistical evidence; they do not substitute for an analysis absent from the record.

What does randomization contribute?

In general, randomization assigns participants to study groups by chance. Its purpose is to reduce systematic differences between groups at the point of assignment, including differences that may not be measured. It does not ensure that every characteristic will be balanced in a particular trial, and it does not correct problems that arise after assignment, such as an endpoint that cannot be measured. The registry says the allocation was randomized, but the method used to generate or conceal assignments is not reported in the registry record.

What does a parallel-group comparison mean?

In a parallel design, the groups are compared as distinct assigned groups. The registry names TRIGEN SURESHOT Distal Targeting and Standard Nailing Instrumentation as the arms. The first used the targeting instrumentation to find screw holes, while the standard approach used free-hand targeting with x-rays. The record states there was no masking. It does not describe whether outcome assessors were masked or provide further details about how procedures were conducted. Those details should not be inferred from the design label.

Why does endpoint measurement matter?

A statistical comparison depends on measurements that represent the outcome of interest. Here, the intended outcome was intraoperative radiation exposure, measured using a whole-body badge and a TLD ring badge. The registry says the dosimeters did not capture radiation dose as expected and marks the primary endpoint voided. When the measurement process does not yield the intended quantity, statistical methods cannot recover a valid exposure comparison merely by analyzing group assignment. The registry does not report a replacement endpoint, an alternative measurement approach, or a usable primary exposure dataset.

What can a confidence interval tell a reader?

In general, a confidence interval expresses uncertainty around an estimated effect under a specified statistical model and its assumptions. A narrow interval indicates greater precision than a wide interval, while an interval that includes values on different sides of a null contrast may leave the direction or size uncertain. These interpretations require an estimate and an interval that have actually been reported. No primary radiation estimate or confidence interval is reported in the registry record, so those concepts cannot be applied to a primary result for this trial.

How should the analysis status be read?

The registry lists zero analyses. This means the posted record does not give a statistical analysis of the outcomes. It does not establish that no analysis was ever conducted outside the registry; that information is not reported in the registry record. The listed secondary outcome is Distal Locking Time, but no result or analysis for it is reported. There is also no reported specification of an analysis population, model, adjustment set, or method for handling missing observations.

What do the sample-size assumptions mean?

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 groups, and a normal approximation. The illustration is defined to consider an effect that is a stated fraction of the observed effect. Such calculations are planning exercises; they are not observed power and do not show that the trial had a particular chance of finding an effect. The registry does not report the trial’s own sample-size justification. Nor does the posted primary endpoint provide a usable radiation effect on which to base an interpretation of the primary question. Any calculated planning illustration should therefore be kept separate from evidence about the trial outcome.

More generally, a p-value, if reported, would address compatibility between observed data and a specified null model, not the probability that a treatment effect is true. No p-value for a primary exposure comparison is reported. Since there is no reported primary analysis, readers should not infer statistical significance, absence of an effect, or precision from the enrollment count alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists Radiation Exposure Measurement as the primary outcome and Distal Locking Time as a secondary outcome. It records two outcome measures overall, but does not report an analysis for either outcome. The primary endpoint was voided because the dosimeters did not capture radiation dose as expected. No method for testing multiple outcomes, adjusting for multiplicity, or prioritizing analyses is reported in the registry record.

Missing-data handling is also not described. The registry identifies a measurement problem affecting the primary endpoint, but does not state how many measurements were unusable, whether any usable observations remained, or whether an alternative analysis was attempted. Those details are not reported in the registry record. The failure to capture dose should not be recast as ordinary participant-level missingness without further information.

The record does not identify an intention-to-treat, per-protocol, or other analysis population. It does not report participant disposition by arm or how deviations from assigned instrumentation were handled. The listed enrollment and adverse-event counts do not establish the analysis population for the primary endpoint. Since the registry lists zero analyses, there is no reported account of exclusions, imputation, sensitivity analyses, or outcome-specific denominators for efficacy analyses. These gaps limit assessment of both multiplicity and missing-data risk.

11. Safety Results

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

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

The registry records zero serious adverse events among 30 at risk in the TRIGEN SURESHOT group and zero among 30 at risk in the standard-instrumentation group. It lists 4 other adverse events among 30 at risk in the TRIGEN SURESHOT group, and 0 among 30 at risk in the standard group. These are the posted counts; the record does not provide a comparative statistical analysis.

The categories should be kept distinct: the listed other events are not listed as serious events. Their descriptions, timing, severity details, and relationship to the instrumentation are not reported in the registry record. The record also does not report death counts. A zero in a listed category means no events were recorded in that category in the posted entry; it does not by itself establish that no event could occur or that the groups have identical safety profiles. These counts should be read as descriptive information from this registry record, not as a complete safety assessment.

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

The trial was designed to compare intraoperative radiation exposure during femoral intramedullary nailing using TRIGEN SURESHOT distal targeting or standard free-hand targeting with x-rays. The primary endpoint was intended to measure exposure using a whole-body badge and a TLD ring badge. The registry states that the dosimeters did not capture radiation dose as expected, so the primary endpoint was voided.

As a result, the posted record does not answer whether measured radiation exposure differed between the approaches. It does not report a primary estimate, an uncertainty interval, or an analysis. That is not evidence that exposure was identical, and it is not evidence that either approach resulted in less exposure. The registry also lists Distal Locking Time as a secondary outcome but does not report its result.

The adverse-event entries offer limited descriptive information: serious adverse events are recorded as zero in each group, while 4 other events are listed in the TRIGEN SURESHOT group and 0 in the standard group. These counts do not establish causation or provide a full comparison of safety. Event details and deaths are not reported in the registry record.

In general, a randomized design can strengthen a comparison when outcomes are measured and analyzed as planned. Here, the design label does not overcome the primary endpoint’s measurement failure. The record does not report why the study was terminated, a sample-size justification, or a statistical analysis. Conclusions should therefore remain limited to the study objective, design, documented endpoint problem, and posted adverse-event counts.

13. Why This Trial Matters Statistically

This study illustrates a basic distinction in clinical research: a well-defined comparison question is not the same as an answer to that question. The registry specifies randomized groups and a primary aim of quantifying radiation exposure for subjects and surgeons during femoral intramedullary nailing. It also identifies the measurement tools intended for that endpoint. But the dosimeters did not capture radiation dose as expected, and the primary endpoint was voided. Without a usable measure, the intended group comparison cannot be interpreted from the registry record.

That distinction is important for biostatisticians and clinical researchers because design and analysis depend on measurement quality. Randomization addresses allocation; it does not repair an outcome instrument that fails to capture the intended quantity. Statistical methods can express uncertainty in recorded data, but they cannot turn a failed measurement into a valid radiation estimate without a defensible alternative measurement strategy.

The record also makes clear why outcome-specific reporting matters. Distal Locking Time is listed as a secondary outcome, but no result is reported. Adverse-event counts are present, yet they do not serve as substitutes for the primary radiation outcome and are not accompanied by a comparative analysis. The record’s terminated status does not explain why the study stopped.

In general, transparent reporting of endpoint status, missing measurements, analysis populations, and analysis methods helps readers understand what evidence a trial contributes. In this case, the most informative statistical conclusion is a boundary: the intended primary comparison cannot be evaluated using the posted record. Recognizing that boundary is more accurate than treating a missing result as evidence for or against a difference.

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 most direct limitation is the failed primary measurement. The registry says the dosimeters did not capture radiation dose as expected and that the primary endpoint was voided. It does not report usable radiation values, the extent of the measurement failure, or an alternative method of analysis.

The registry lists no analyses. It does not report results for the secondary outcome, Distal Locking Time, or identify analysis populations, statistical models, missing-data procedures, or multiplicity handling. Details of eligibility criteria, participant characteristics, participant flow, and the randomization procedure are not reported in the registry record.

The study is marked terminated, but the reason for termination is not reported. The record does not explain whether termination was related to dosimeter performance or another issue. It also does not report a sample-size justification. The listed sample-size assumptions describe planning illustrations rather than the trial’s own design rationale or observed power.

Safety interpretation is limited as well. The adverse-event record gives counts but not event descriptions, timing, attribution, or death counts. It does not provide an inferential comparison. These limitations mean the posted record offers a description of the intended study and some adverse-event counts, but not a usable statistical evaluation of the primary radiation question.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: TRIGEN SURESHOT™ Distal Targeting System Study — NCT01327508.
• Registry record last updated 2018-03-14; status last verified 2018-02.
• Results first posted 2016-02-09.
• 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.

18. Record Summary

NCT01327508 is a prospective, multi-center, randomized, unmasked, parallel comparison of TRIGEN SURESHOT Distal Targeting and standard nailing instrumentation for femoral shaft fracture procedures. The stated objective was to quantify radiation exposure for subjects and surgeons during intramedullary nailing. The registry lists enrollment of 60, a start of 2011-04, primary completion of 2013-01, and status of terminated.

The primary intraoperative Radiation Exposure Measurement endpoint used a whole-body badge and a TLD ring badge. It was voided because dosimeters did not capture radiation dose as expected. Distal Locking Time is listed as a secondary outcome, with no result reported. The registry lists zero analyses. Serious adverse events are recorded as zero among 30 at risk in each group; other adverse events are listed as 4 in the TRIGEN SURESHOT group and 0 in the standard group. The reason for termination and death counts are not reported in the registry record.