MDR EZ Pass and Precision Flexible Reamer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for MDR EZ Pass and Precision Flexible Reamer (NCT03914703), a registered phase not stated study. The primary outcome is Performance of Instruments (EZ Pass Suture Passer and Precision Flexible Reamer).

2. Clinical Question

3. Trial Design

NCT03914703 is a completed post-market clinical follow-up study sponsored by Zimmer Biomet. Its official title describes a retrospective consecutive series intended to collect safety, performance, and clinical data for the EZPass Suture Passer and Precision Flexible Reamers. The registry lists enrollment of 73 and a study start of 2019-08-08, with primary completion on 2023-12-31.

The record describes two instrument groups. Patients in the EZ Pass Suture Passer group had surgery using that instrument in rotator cuff or soft tissue repair. Patients in the Precision Flexible Reamer group had surgery using that instrument in ACL repair. These different clinical contexts matter for interpretation: the groups are not presented as interchangeable treatment arms, and the registry explicitly notes that allocation was not stated and that the arms are not a like-for-like control comparison.

The primary outcome is an intraoperative assessment of whether the instrument performed as expected. A surgeon answered yes or no on a questionnaire. The record also lists safety outcomes, including serious events, other events, and deaths, by instrument group. It lists 2 outcome measures but no analyses.

The record does not report details about eligibility criteria, recruitment procedures, the timing or length of follow-up for safety outcomes, or how missing observations were handled. It also does not report a protocol or analysis plan. The retrospective consecutive-series description signals that the study is based on a sequence of cases rather than a stated randomized allocation, but the record does not describe the process used to identify or enroll cases.

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.

Population: Patients who have received either the EZ Pass Suture Passer or the Precision Flexible Reamer.

6. Primary Endpoint

The registry lists the primary outcome as Performance of Instruments (EZ Pass Suture Passer and Precision Flexible Reamer), measured over Intraoperative.

The primary endpoint is titled “Performance of Instruments (EZ Pass Suture Passer and Precision Flexible Reamer).” It counts participants, and the stated assessment is whether the instrument performed as expected during the procedure. The surgeon completes a questionnaire and gives a yes/no opinion. The timeframe is intraoperative.

This kind of endpoint captures an immediate, operator-reported assessment of device performance in the surgical setting. It can describe whether the instrument met the surgeon’s expectation while it was being used. As a binary measure, the response classifies each assessed participant into one of two response categories rather than describing a continuous measurement or the degree of performance.

The endpoint does not, on its own, establish a comparative effect or cover every aspect of safety, longer-term clinical outcomes, or patient experience. Its meaning depends on who completed the questionnaire, how “performed as expected” was interpreted, and whether responses were recorded consistently. Those implementation details are not reported in the registry record. The registry gives the endpoint definition but does not report the yes/no response counts, so the performance result itself cannot be described from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes an observational, retrospective consecutive series. That description differs from a randomized trial: the record does not state that patients were assigned by chance to instruments, and it says allocation was not stated. The instrument groups also relate to different procedures. As a result, a direct comparison between their counts would mix differences in instrument use with differences in surgical context and potentially other case characteristics. The record does not supply a design that isolates an instrument-specific causal effect.

What does a binary endpoint mean?

The primary endpoint records a yes/no response to whether the instrument performed as expected. A binary endpoint places each response into one of two categories. For a meaningful group summary, the response count and the number assessed in each category are needed. The registry describes the endpoint but does not report those response counts. Accordingly, no performance proportion or comparison can be interpreted from the posted record.

Binary outcomes are often presented as counts and proportions. An uncertainty interval around a proportion can communicate the range of values compatible with the observed data under a statistical model. Such an interval does not guarantee that the true value lies within it, and its width reflects the amount of information and assumptions used. No performance estimate or interval is reported for this endpoint in the registry record.

Why is the arm structure important?

The EZ Pass Suture Passer group concerns rotator cuff or soft tissue repair, whereas the Precision Flexible Reamer group concerns ACL repair. When groups differ in procedure and indication, their observed outcomes are not automatically comparable. A difference in counts could reflect case mix, practice, follow-up, or other factors rather than an instrument effect. Without random allocation or a reported adjustment strategy, a between-group contrast would not have a clear causal interpretation. The registry reports no analyses.

The record’s description of a retrospective consecutive series indicates that cases were reviewed as a series after the fact. Consecutive case selection can help describe clinical use, but the label alone does not establish that every eligible case was captured or that observation and outcome recording were complete. The inclusion process and missing-data procedures are not reported in the registry record.

How should the safety counts be read?

For each group, the record gives participants at risk and counts of participants affected. It reports serious events separately from other events and also lists deaths. These are participant counts, not a measure of how often events occurred over person-time. The record does not describe event duration, recurrence, severity beyond the serious-event category, or follow-up time. If multiple events could occur for one participant, event counts and affected-participant counts could differ; the registry information reports affected participants for the categories.

Observed counts are descriptive, especially in a case series without a stated comparator. A zero count means that none was recorded in the reported group; it does not establish that the underlying risk is zero. Statistical uncertainty is generally greater when observations are limited, and a confidence interval can make that uncertainty explicit. The registry record does not report confidence intervals for these safety counts.

What do planning calculations represent?

Any sample-size figures associated with planning illustrations should be interpreted as hypothetical planning quantities, not as outcomes observed in this study and not as the study’s original design. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. The registry does not report that these assumptions were used to design the study. Such calculations do not establish observed power or show that the study could reliably detect a particular effect.

More generally, a significance level describes a decision threshold used in a specified testing procedure; it does not measure the probability that a finding is true. Sample-size planning depends on the target effect, outcome variability, allocation, and analysis method. If those assumptions do not match the study design or the intended question, the resulting planning quantities may not apply. The record does not report a protocol-based sample-size justification or analysis plan.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures and no analyses. It does not report a multiplicity strategy, such as a prespecified hierarchy of outcomes or an adjustment for multiple statistical tests. Without reported inferential analyses, there are no listed test results to assess for multiplicity. The absence of a reported strategy should not be taken as evidence that a particular method was or was not used outside the registry record.

The record describes the primary performance question but does not give the yes/no response counts. It also does not report the number assessed for that endpoint in either instrument group, reasons for missing questionnaires, or how missing responses were handled. Therefore, the completeness of the primary endpoint data cannot be evaluated from the record.

Analysis populations are also not described. The registry does not state whether every enrolled participant was included in each outcome summary, whether exclusions occurred, or how participants with incomplete observations were treated. The safety figures include participants at risk for each listed category, but the record does not explain how those denominators were determined or whether follow-up was uniform.

For the safety outcomes, event definitions, ascertainment procedures, follow-up duration, and handling of recurrent events are not reported in the registry record. These omissions limit interpretation of both the observed counts and the extent to which participants had comparable opportunities for events to be observed. No assumptions about missingness or analysis populations can be justified from the posted information.

11. 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

The registry reports serious-event counts alongside the number at risk in each group. For the EZ Pass Suture Passer group, 0 serious events are reported among 51 participants at risk; for the Precision Flexible Reamer group, 0 are reported among 22 participants at risk. Deaths are reported as 0 in both groups. The other-event counts are 5 participants in the EZ Pass Suture Passer group and 2 in the Precision Flexible Reamer group.

These figures are descriptive participant counts, not a randomized comparison. The groups represent different instruments and surgical settings, and the record does not state allocation. The other-event category is not defined in further detail, and event timing, follow-up duration, severity details, and ascertainment procedures are not reported in the registry record.

A zero count means no event of that type was recorded in the stated group; it does not show that the underlying risk is zero. The record does not provide uncertainty intervals or event-level details, so the precision and clinical context of these safety observations cannot be fully assessed.

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

The record establishes that a completed post-market retrospective consecutive series was registered to collect safety, performance, and clinical data for the EZ Pass Suture Passer and Precision Flexible Reamer. It describes the intended primary assessment as an intraoperative surgeon opinion about whether the instrument performed as expected. It also reports safety counts by instrument group, including no recorded serious events and no deaths in either group, alongside the counts of participants with other events.

These observations do not establish that either instrument is superior to the other. The groups concern different procedures, allocation is not stated, and the record cautions that they are not a like-for-like control comparison. The primary performance responses are not reported, so the central performance question cannot be answered from the posted results. The safety counts also cannot establish a comparative risk or demonstrate the absence of risk.

The record does not report statistical analyses, confidence intervals, outcome definitions beyond the brief descriptions, or follow-up details. Without those elements, readers cannot assess the precision of the estimates, determine whether observation was complete, or evaluate how case differences may have affected outcomes. The enrollment count and safety denominators describe the registered study information but do not fill those reporting gaps.

In general, post-market case series can contribute descriptive information about instrument use in clinical practice. They can document observed outcomes and identify questions for further study, but causal conclusions usually require a design and analysis that address selection, comparison groups, and potential confounding. For this record, interpretation should remain limited to the stated design and recorded counts. It does not support a claim that an instrument works or does not work, nor does it provide a quantified estimate of performance.

13. Why This Trial Matters Statistically

This study is statistically important to read as a descriptive post-market series rather than as a controlled comparison. The record covers two instruments used in different surgical settings, and it does not state how patients were allocated. Those features determine what the observed data can answer: they can describe recorded experience within each group, but they do not by themselves identify the effect of one instrument relative to the other.

The distinction between a defined outcome and a reported result is also central. The registry specifies an intraoperative yes/no judgment of whether the instrument performed as expected, but does not give the response counts. A well-defined endpoint is not enough to estimate performance when its observed responses are unavailable. This makes transparent outcome reporting essential to interpreting a study, even when the design and question are clearly described.

The safety information illustrates another statistical principle: observed absence is not the same as evidence of no risk. Zero serious events and zero deaths are the recorded counts, but the record does not provide uncertainty intervals, follow-up duration, or details of event ascertainment. Those omissions prevent a full assessment of how precisely the observations characterize safety.

Finally, planning calculations should be kept separate from results. The stated assumptions describe hypothetical planning illustrations, not the original design or observed power. Clear separation of descriptive data, inferential analysis, and planning assumptions helps prevent a case series from being read as stronger comparative evidence than its design and reporting 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 principal limitation is that the registry does not report the primary endpoint responses. Although the surgeon questionnaire and its yes/no format are described, no response counts or performance estimate are given. The primary question therefore remains unanswered by the posted results.

The two groups are not a like-for-like comparison: they involve different instruments and surgical settings. Allocation is not stated, and the registry identifies the study as a retrospective consecutive series. The record does not report methods for selecting cases, eligibility criteria, or adjustment for differences among patients or procedures. A causal comparison between instruments is not supported by the information recorded.

Safety interpretation is limited by the absence of further detail about the other-event category, event ascertainment, timing, follow-up duration, and whether recurrent events were possible. The record also does not report confidence intervals or inferential analyses. It is therefore not possible to quantify uncertainty or assess the precision of the recorded counts using the registry information.

Missing data and analysis populations are not described. The record does not state whether all enrolled participants contributed to each outcome, whether any observations were unavailable, or how such observations were handled. Finally, the planning assumptions listed for illustrative sample-size calculations are not reported as the study’s original design assumptions. These limitations constrain conclusions to a description of the registered study and its reported safety counts.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: MDR EZ Pass and Precision Flexible Reamer — NCT03914703.
• Registry record last updated 2025-07-01; status last verified 2025-06.
• Results first posted 2025-07-01.
• 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

NCT03914703 is a completed, sponsor-listed post-market clinical follow-up study described as a retrospective consecutive series. Its stated objective is to assess safety and performance of the EZ Pass Suture Passer and Precision Flexible Reamer. Enrollment is reported as 73. The primary measure is an intraoperative surgeon yes/no assessment of whether the instrument performed as expected, but the response counts are not reported in the registry record.

The registry reports safety counts separately for the two instrument groups: serious events and deaths are recorded as 0 in each group, while other events are reported for 5 participants in the EZ Pass Suture Passer group and 2 in the Precision Flexible Reamer group. The groups concern different surgical settings, allocation is not stated, and the registry notes that they are not a like-for-like control comparison. No analyses are listed, and details about follow-up, missing data, and analysis populations are not reported.