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 Ambispective Study Evaluating the Clinical Results of SAGITTA EVL R Revision Stems (NCT06096168), a registered phase not stated study. The primary outcome is Survival Rate at Mid Term Follow-up.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT06096168 |
| Phase | Phase not stated |
| Condition | Hip Arthropathy |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 42 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Societe dEtude, de Recherche et de Fabrication |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with Hip Arthropathy undergoing hip arthroplasty with revision femoral stems. The registry describes a comprehensive and continuous series intended to reflect current practice. Enrollment was 42. The primary endpoint refers to implants followed at least 4 years after surgery, with the stated mid-term timeframe between 4 to 7 years after surgery. The registry record does not describe further eligibility criteria or provide details about the patients’ clinical characteristics.
Intervention
The device under study is the SAGITTA EVL R revision femoral stem manufactured by SERF. The study’s stated purpose is to collect clinical data on hip arthroplasty using these stems and to evaluate their performance and safety in the framework described in the study summary. The record does not report details of the surgical procedures, postoperative care, or how use of the device was managed across participating patients.
Comparator
No comparator group is identified. The record does not describe randomization, and allocation is not stated. The study is therefore not presented as a randomized comparison, and the registry information does not establish a like-for-like control group. Any results should be read as observations from the study series, not as an estimate of how the device compares with another implant or treatment.
Primary question
The primary question is the percentage of implants remaining in place without revision at mid-term follow-up. The registry defines this as cumulative implant survival, regardless of the cause of revision, calculated using Kaplan-Meier methods. The planned timeframe is between 4 to 7 years after surgery, with assessment at least 4 years after surgery. The registry record does not report the resulting survival estimate, its precision, or the number of implants observed at each follow-up time.
3. Trial Design
This is an ambispective study of the SAGITTA EVL R revision femoral stems. The study summary describes a comprehensive and continuous series of patients intended to reflect current practice. “Ambispective” indicates that a study may combine retrospective and prospective data collection in general; the registry record does not specify which data were collected retrospectively or prospectively, or how those components were organized.
The listed enrollment is 42, and the study status is COMPLETED. The record gives a study start date of 2023-04-13 and a primary completion date of 2024-10-29. These dates describe the registry record’s study timeline; they do not establish the follow-up duration for each patient. The primary endpoint’s stated follow-up window is between 4 to 7 years after surgery, and the description calls for at least 4 year-follow-up.
The sponsor is Societe dEtude, de Recherche et de Fabrication. Hip Arthropathy is the listed condition. The study summary frames the work as clinical-data collection to monitor the claimed performance and safety of the device under the cited regulatory and clinical-evaluation framework.
No randomized allocation is described, and allocation is not stated. No control group or direct treatment comparison is identified. The study should therefore be understood as a clinical series rather than as a randomized comparison. The record does not report further design details such as the number of sites, recruitment procedures, eligibility criteria, or the data collection schedule. It also does not report a sample-size justification. Without those details, the design can be described only at the level recorded: an ambispective series, enrollment of 42, and evaluation of implant survival and additional 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 | Per Protocol Population |
|---|---|
| STARTED | 42 |
| COMPLETED | 10 |
| NOT COMPLETED | 32 |
Reasons for not completing this period:
| Reason | Per Protocol Population |
|---|---|
| Death | 30 |
| Revision | 2 |
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 | Per Protocol Population |
|---|---|---|
| Participants analysed | 42 | |
| Age, Continuous | years | 80.4 (SD 8.24) |
| Sex: Female, Male: Female | Participants | 18 |
| Sex: Female, Male: Male | Participants | 24 |
| Weight | kg | 72.8 (SD 19.0) |
6. Primary Endpoint
The registry lists the primary outcome as Survival Rate at Mid Term Follow-up, measured over Between 4 to 7 years after surgery.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of implant survival |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the survival rate at mid-term follow-up, expressed as the percentage of implants not revised and remaining in place. The registry specifies that revision is counted whatever its cause, so the endpoint concerns all-cause revision rather than a particular reason for revision. It describes cumulative survival calculated using the Kaplan-Meier method, with assessment at least 4 year-follow-up and a timeframe between 4 to 7 years after surgery.
Implant survival is used to summarize how long implants remain in place without revision over follow-up. Unlike a simple proportion at one fixed time, a time-to-event method can use information from participants whose follow-up ends before the endpoint is observed. In general, those observations are handled as censored when the event has not been seen by the last time they are known to be followed. The assumptions and censoring procedures used in this study are not reported in the registry record.
The primary outcome description gives the method and target measure, but not the observed survival estimate. The registry record also does not report a confidence interval, the number of revisions contributing to the estimate, or the number of implants remaining under observation over time. Accordingly, the endpoint definition is available, while its estimated value and precision are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record establishes the study’s subject, primary outcome definition, enrollment, and some safety information. It does not report the primary implant-survival estimate. As a result, the posted results do not indicate what percentage of implants remained in place without revision at the stated mid-term follow-up. They also do not give a confidence interval or other measure of precision for that endpoint. The study’s stated aim and a defined method are not substitutes for a reported result.
The primary endpoint is a time-to-event measure. Its interpretation would ordinarily depend on the observed number and timing of revisions, the duration of follow-up, and how many implants remained under observation as time passed. Those details are not reported in the registry record. The timeframe is described as between 4 to 7 years after surgery, with assessment at least 4 year-follow-up; this does not by itself show how many participants reached each follow-up time or how much information contributed to the estimate.
The registry lists secondary outcome categories including adverse events, survival rates by component and by etiology, patient satisfaction, oblivion of prosthesis, and functional improvement. Numerical results for these outcomes are not reported in the registry record. Their inclusion indicates areas of planned or recorded assessment, but does not establish what was observed or how the outcomes were measured.
For safety, the per-protocol population is listed with 42 at risk in both the serious-event and other-event entries. The corresponding affected counts are 4 and 1, and the record lists 30 deaths. Four serious-event terms are each accompanied by 2.4%: Sepsis, Posterior dislocation, Femoral fracture, and Fracture with greater trochanter displacement. The denominator and term-specific event counts are not reported, so the percentages cannot be interpreted as a complete account of event frequency or compared directly with another population.
In general, an estimate is more informative when its uncertainty and the amount of follow-up information are reported alongside it. Here, the primary estimate and its precision are not reported in the registry record. The status COMPLETED indicates the study’s recorded status, but completion alone does not supply missing outcome results. The absence of a comparator also limits interpretation: these data cannot establish a relative effect against another implant or treatment.
9. Statistical Methods Explained
The registry identifies Kaplan-Meier calculation as the method for the primary survival endpoint. It also records no analyses in its analysis count. These statements should be read separately: the endpoint description names a method for calculating survival, while the record does not provide analysis results or further details of the statistical analysis plan.
What does Kaplan-Meier survival mean?
In general, Kaplan-Meier estimation describes the probability of remaining free of an event over time. For this study, the event is revision of the implant, whatever its cause. The resulting cumulative survival measure is intended to describe the percentage of implants not revised and remaining in place over the stated follow-up period.
In general, time-to-event methods can include participants whose follow-up ends before revision is observed. Such information is usually treated as censored at the last time the participant is known to be followed. This lets the estimate use partial follow-up rather than treating every participant as if they had the same observation period. The registry record does not specify how censoring was defined or handled, whether follow-up was complete, or how losses to follow-up were addressed.
A Kaplan-Meier estimate is ordinarily interpreted with information about the number of events and the number still under observation over time. A confidence interval is also useful: in general, it describes uncertainty around an estimated value, rather than guaranteeing that the true value lies within a particular range. The registry record does not report the primary survival estimate, a confidence interval, event counts for the primary endpoint, or numbers at risk over time. Therefore, its precision and the amount of information supporting it cannot be assessed from the recorded results.
What does “whatever the cause of revision” imply?
The definition combines revisions regardless of their cause. This means the primary endpoint is not restricted to revisions attributed to a particular component, complication, or underlying reason. The record separately lists secondary survival outcomes by component and by etiology, but does not report their results or describe the categories used to classify components and etiologies.
In general, a broad endpoint can capture the overall occurrence of the event while leaving questions about specific causes to separate analyses. The registry description does not state whether any revisions were adjudicated, how causes were assigned, or how competing events were handled. Those procedures are not reported in the registry record.
What can be inferred from the analysis information?
The registry lists no analyses. It does not provide an analysis plan, specify any adjustment variables, or describe methods for subgroup analysis. The outcome description’s reference to Kaplan-Meier calculation identifies a method, but it does not explain whether the estimate was adjusted, how uncertainty was calculated, or what population was used for the primary endpoint. Those details are not reported in the registry record.
The per-protocol population appears in the safety information, with 42 at risk in the serious-event entry and 42 at risk in the other-event entry. The registry does not define this population or explain whether it was used for the primary survival analysis. The primary outcome’s population field is blank. It is therefore not possible to determine from the record whether the primary endpoint was analyzed in the same population as the safety outcomes.
How should planning calculations be understood?
In general, sample-size planning asks how many observations might be needed to detect a specified effect under stated assumptions. The planning assumptions recorded for this study describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. For time-to-event planning, the stated approach counts total events using Schoenfeld; other planning calculations are expressed as participants per arm.
These are planning assumptions, not a description of the study’s design or proof of its ability to detect an effect. The registry does not describe a randomized two-arm comparison, and no allocation is stated. A planning illustration based on an observed effect is not observed power. The registry record does not report the trial’s own sample-size justification, and the planning assumptions do not establish that the enrolled series was designed to test a comparative hypothesis.
10. Multiplicity, Missing Data and Analysis Populations
The record lists the primary survival endpoint and secondary outcome categories, but does not report how statistical testing across outcomes was planned or interpreted. It does not state whether any multiplicity adjustment was used, whether outcomes were tested in a hierarchy, or which outcomes were intended to support confirmatory conclusions. Those details are not reported in the registry record.
In general, evaluating several outcomes can increase the chance of seeing at least one apparently notable result by chance if each is tested separately. Methods for handling multiple comparisons can help control that issue, but the appropriate approach depends on the objectives and analysis plan. Since neither test results nor a multiplicity strategy are reported, the registry record does not allow readers to assess how this issue was addressed.
Missing-data methods are also not described. The record does not report the extent of missing follow-up, reasons for missingness, or how missing outcome information was handled. For a time-to-event endpoint, follow-up that ends before revision may be censored, but the study-specific rules are not reported. No assumptions about missingness or censoring should be inferred from the named Kaplan-Meier method alone.
The safety information identifies a per-protocol population, but does not define it. The primary endpoint population is not specified. The record therefore does not establish which participants contributed to each outcome or whether the same analysis population was used throughout. These gaps limit assessment of the completeness and comparability of the reported outcome information.
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 |
|---|---|---|---|
| Per Protocol Population | 4 | 42 | 9.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Per Protocol Population | 30 of 42 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 2% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Per Protocol Population | 1 of 42 |
Most frequent serious adverse event terms
| Event term | Organ system | Per Protocol Population |
|---|---|---|
| Sepsis | Infections and infestations | 1 of 42 |
| Posterior dislocation | Surgical and medical procedures | 1 of 42 |
| Femoral fracture | Surgical and medical procedures | 1 of 42 |
| Fracture with greater trochanter displacement | Surgical and medical procedures | 1 of 42 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Per Protocol Population |
|---|---|---|
| Greater trochanter fracture | Surgical and medical procedures | 1 of 42 |
Serious events with the highest arm-level rate: sepsis (2.4%), posterior dislocation (2.4%), femoral fracture (2.4%), fracture with greater trochanter displacement (2.4%).
The safety information is associated with the per-protocol population. It lists 42 at risk in the serious-event entry and 42 at risk in the other-event entry. The affected counts recorded in those entries are 4 for serious events and 1 for other events. The record also lists 30 deaths. It does not explain the relationship between the death count and the adverse-event entries, so the deaths should not be assumed to be caused by an event or by the device.
The serious-event terms listed are Sepsis, Posterior dislocation, Femoral fracture, and Fracture with greater trochanter displacement. Each term is accompanied by 2.4%. The registry does not state the denominator or provide term-specific counts alongside these percentages. It also does not report timing, severity criteria, relatedness to the device, or whether events could be counted more than once for an individual.
In general, adverse-event figures describe events recorded under a study’s definitions; they do not, by themselves, establish causation. The available figures are a limited safety description and should not be read as a complete event profile or as a comparison with another treatment. Further details are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The study record describes an ambispective clinical series evaluating SAGITTA EVL R revision femoral stems. It identifies implant survival at mid-term follow-up as the primary endpoint and gives a Kaplan-Meier method for calculating that outcome. It also records enrollment of 42 and includes limited adverse-event figures for a per-protocol population.
The registry record does not report the primary survival estimate, its confidence interval, or the number and timing of revisions. It also does not report numerical results for the named secondary outcomes. Consequently, the posted data do not quantify implant survival or the degree of uncertainty around it. The absence of a reported estimate is not evidence that survival was high or low; it leaves the endpoint result unreported in the registry record.
The design is not described as randomized, and the record identifies no comparator. Therefore, it does not provide a like-for-like comparison with another implant or approach. In general, a clinical series can describe outcomes observed among its participants, but without a comparator it cannot by itself separate outcomes associated with the device from other factors that may influence results. The record does not report details that would allow adjustment for such factors.
The safety entries give counts and percentages, but important interpretive details such as event definitions, denominators for the listed percentages, and attribution are absent. These figures should be treated as the recorded safety information, not as proof of causality or a complete account of risk.
The study’s completed status and stated regulatory monitoring purpose provide context for why data were collected. They do not fill the gaps in the posted outcome results. A fuller assessment would require the survival estimate and its uncertainty, follow-up and event details, and information on the analysis population and methods; these are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically notable for its focus on a time-to-event outcome in a clinical series. Implant survival is not simply a count of implants present at one moment: the primary definition concerns the time until revision, with follow-up potentially differing between participants. Kaplan-Meier estimation is named as the method, making clear that the endpoint is intended to account for time-to-event information.
At the same time, the value of a survival estimate depends on its accompanying information. In general, event counts, follow-up duration, numbers at risk over time, and uncertainty intervals help readers judge how much evidence supports an estimate. The registry record does not report these details or the primary estimate itself. This makes the distinction between a defined statistical endpoint and a reported statistical result especially important.
The series is described as comprehensive and continuous to reflect current practice, but no randomized allocation or comparator is identified. That design context shapes what statistical claims can be supported: observations can describe outcomes in the enrolled series, but the record does not offer a direct comparison against another treatment. The absence of a comparator is not a flaw that can be fixed by a different statistical test; it is a limit on the type of inference available from the described design.
Finally, the record lists several secondary outcomes alongside the primary endpoint, while analysis methods and results are not reported. Without an analysis plan, readers cannot evaluate how multiple outcomes, missing follow-up, or population definitions were handled. The study illustrates why clear outcome definitions are useful, and why transparent reporting of estimates, uncertainty, and analysis details is also needed for statistical interpretation.
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.
Several trial-specific limitations follow from the information recorded. The primary endpoint is defined, but its survival estimate and precision are not reported. Event counts for revisions, follow-up distributions, numbers at risk over time, and censoring details are also absent. Without these items, readers cannot assess how much follow-up information supports the primary endpoint or how stable its estimate may be.
The registry does not identify a comparator, and allocation is not stated. It does not describe randomization. The series therefore cannot be interpreted as a randomized comparison, and the record does not support a direct estimate of relative outcomes against another implant or treatment.
The per-protocol population is not defined, and the population for the primary outcome is not specified. Although 42 are listed as at risk in each of the two safety entries, the record does not describe how participants were included in those entries or whether the primary endpoint used the same population. The handling of missing data and loss to follow-up is not reported.
The safety figures are limited: the record lists affected counts, deaths, and four serious-event terms with percentages, but does not give the denominator for the term percentages, event timing, relatedness, or detailed definitions. These omissions restrict interpretation of the frequency and context of adverse events.
Finally, the statistical analysis plan, any multiplicity approach, and the trial’s sample-size justification are not reported in the registry record. The study’s stated completion status does not resolve these reporting gaps.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Ambispective Study Evaluating the Clinical Results of SAGITTA EVL R Revision Stems — NCT06096168.
- Registry record last updated 2025-06-25; status last verified 2025-04.
- Results first posted 2025-06-25.
- 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 NCT06096168, an ambispective study of SAGITTA EVL R revision femoral stems manufactured by SERF. Hip Arthropathy is the listed condition, and enrollment is 42. The study is recorded as COMPLETED, with a start date of 2023-04-13 and a primary completion date of 2024-10-29.
The primary endpoint is implant survival at mid-term follow-up, expressed as the percentage of implants not revised and remaining in place, regardless of revision cause. The stated method is Kaplan-Meier calculation, with follow-up described as between 4 to 7 years after surgery and at least 4 year-follow-up.
The registry lists secondary outcomes covering adverse events, survival by component and etiology, patient satisfaction, oblivion of prosthesis, and functional improvement. It includes safety figures for a per-protocol population, but does not report the primary survival estimate or statistical analysis results. Further analysis, population, and missing-data details are not reported in the registry record.