Safety of Treatment of Shoulder Repair: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety of Treatment of Shoulder Repair (NCT04552119), a registered phase not stated study. The primary outcome is Clinical Success Rate at 6 Months.

2. Clinical Question

In practical terms, the study question is whether participants receiving these devices had a second repair procedure during the stated follow-up period, as framed by the registry’s clinical-success outcome. The record also lists patient and clinician assessment measures, including the Constant-Murley Score, the American Shoulder and Elbow Surgeons Score, pain and shoulder scales, and quality-of-life measures. Those outcomes broaden the planned description of follow-up beyond the primary repair-related measure, but numerical results for them are not reported in the registry record.

3. Trial Design

This is a prospective, multi-center, post-market clinical follow-up study, as described in the official title. It evaluates safety and performance of HEALICOIL Knotless Suture Anchors in shoulder rotator cuff tendon repair. The registry lists enrollment of 138 and gives the study status as completed. The recorded start date is 2021-01-26, and the primary completion date is 2024-05-24.

The record identifies two device arms: HEALICOIL Knotless PEEK and HEALICOIL Knotless REGENESORB. Participants in the safety population are described as those who received a study device and had data collected for the relevant time frame. The record does not say how participants were assigned to the arms. It explicitly notes that the study was not a randomized comparison and that the arms are not a like-for-like control comparison. Differences between their observed outcomes, if reported, would therefore not by themselves establish that the device variant caused a difference.

The primary outcome is clinical success rate at 6 months, with the unit recorded as participants. The registry also lists clinical success at 12 months and, for a specified REGENESORB anchor, at 24 months, along with shoulder function, pain, and quality-of-life outcomes. The listed follow-up measures include the Constant-Murley Score, ASES Score, ASES pain score, SANE shoulder scale, and EQ-5D-3L measures. The record names 11 outcome measures, but lists no analyses. Numerical results for the primary and secondary outcomes are not reported in the registry record.

Further details of allocation, eligibility criteria, site numbers, visit schedules, and the statistical analysis plan are not reported in the registry record. The registry states that Smith & Nephew, Inc. is the sponsor. The study’s completed status indicates the recorded study status, but does not itself provide outcome estimates or establish how complete the follow-up data were.

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:

Analysis population for the primary outcome, as defined in the registry: Safety population (SAF) included participants that received the study device with data collected for the time frame specified.

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: Safety Population (SAF) included those that received the study device with data collected.

6. Primary Endpoint

The registry lists the primary outcome as Clinical Success Rate at 6 Months, measured over 6 months.

The primary endpoint is the clinical success rate at 6 months, measured in participants. The registry description connects clinical success to the repair failure rate and defines failure as the need for a second repair procedure. That procedure could be a repair of the original rotator cuff and/or a biceps tenodesis from the index procedure.

This endpoint focuses on whether a further repair procedure was needed after the initial operation. As a clinical follow-up measure, it captures a consequential event related to the durability of the original repair, rather than relying only on a score reported at a follow-up visit. The registry’s description does not provide a numerical success rate, number of failures, confidence interval, or analysis for this endpoint. It also does not give additional detail about how a participant’s outcome was classified if follow-up was incomplete or if a second procedure occurred for another reason.

The wording needs careful reading: the outcome is titled clinical success, while its description defines repair failure. The registry record does not state the precise coding rule translating failure events into the reported success-rate value. Without a posted outcome result and a fuller definition, no direction or magnitude of the endpoint can be inferred. The timeframe is 6 months; it should not be conflated with the separate 12-month clinical success outcome also listed in the registry.

In general, a time-specific endpoint helps focus interpretation on a defined follow-up point. It does not describe what happened outside that window, and it cannot substitute for the other listed measures of pain, shoulder function, or quality of life. Those measures address distinct aspects of participants’ experience and are listed as secondary outcomes, but their numerical findings are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What an outcome estimate would mean. The primary measure is a participant-level clinical-success rate at 6 months. In general, a rate describes the proportion of an outcome population meeting a defined event criterion. For this study, the registry names participants as the unit and relates the outcome to repair failure, defined as a need for a second repair procedure. However, the registry record does not report the observed primary outcome estimate or the coding details needed to verify how failure status maps to the title of clinical success. No numerical rate can therefore be interpreted from the record.

Uncertainty and confidence intervals. In general, a confidence interval describes the range of values compatible with an estimate under the assumptions of the statistical method. It helps distinguish a relatively precise estimate from one with substantial uncertainty. The registry record does not report a confidence interval for the primary outcome or the listed secondary outcomes. Without both an estimate and its uncertainty interval, the precision of the clinical findings cannot be assessed.

Between-arm comparisons. The record names HEALICOIL Knotless PEEK and HEALICOIL Knotless REGENESORB as arms. It says allocation was not stated, identifies the study as not randomized, and cautions that the arms are not a like-for-like control comparison. In general, a non-randomized comparison can be affected by differences between the groups that existed before treatment or arose during follow-up. A simple difference in observed outcomes would not isolate a device effect. No adjusted comparison, model, or statistical test is listed in the registry record.

Counts and rates. The adverse-event entries report numbers at risk and numbers affected for serious events and other events. In general, a count is the number of participants recorded in a category; it is not the same as a rate over person-time. A participant may also contribute to more than one event category unless the reporting rules specify otherwise. The registry record does not explain whether categories overlap, how event onset or duration was handled, or whether observation time differed between participants. The figures are therefore best read as descriptive entries, not as a comparative model or a complete account of event burden.

Why over-dispersion can matter. In general, over-dispersion occurs when observed variability is greater than a statistical model assumes. It can make standard errors too small if a model does not account for the extra variability. This concept is relevant to some count-data analyses, but the registry lists no analysis for the outcomes in this study. It does not report whether a count model was used or whether over-dispersion was assessed, so no claim about the study’s handling of it can be made.

Planning calculations and observed results. In general, sample-size planning uses assumptions about the effect to detect, allocation, significance level, and statistical method. The registry record does not report the study’s own sample-size justification or original design assumptions. It also does not provide a numerical primary outcome estimate from which an effect could be interpreted. Planning illustrations based on an observed effect are not observed power and do not replace an outcome analysis. No numerical planning results are reported in the registry record.

Multiple outcomes. The record lists a primary outcome and multiple secondary outcomes. When several outcomes or comparisons are tested, general statistical practice considers multiplicity because repeated testing can increase the chance of at least one apparently notable finding arising by chance. A multiplicity strategy, hierarchy for secondary outcomes, or adjusted significance threshold is not reported in the registry record. Since no analyses are listed, the record also does not indicate which outcomes were tested or how any testing was interpreted.

Missing observations and analysis populations. In general, missing outcome data can affect an estimate if participants with missing measurements differ systematically from those with observed measurements. The record defines the safety population as participants who received a study device and had data collected for the stated timeframe. It does not provide a flow of participants by follow-up visit, missing-data counts, imputation methods, or sensitivity analyses. The handling of missing outcome data is therefore not reported in the registry record. The safety-population definition should not be assumed to describe the analysis population for every listed outcome.

How to read the available evidence. The registry supplies descriptive information about the design and some safety counts, but no outcome analyses. In general, an estimate, its uncertainty, the population analyzed, and the analysis method are all needed to assess what a clinical comparison can show. Those elements are not available for the primary endpoint in the registry record. Statistical interpretation must consequently remain limited to the recorded study design, endpoint definitions, and adverse-event entries, without inferring efficacy or comparative performance.

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("HEALICOIL Knotless PEEK", "HEALICOIL Knotless REGENESORB")
n      <- c(58, 68)
events <- c(58, 68)
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  HEALICOIL Knotless PEEK  58  58  100.0  93.8  100.0  93.8  100.0  93.9  100.0
ARM  HEALICOIL Knotless REGENESORB  68  68  100.0  94.7  100.0  94.7  100.0  94.8  100.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary endpoint and numerous secondary outcomes, covering clinical success at later follow-up, shoulder function, pain, shoulder self-assessment, and quality of life. When several outcomes are examined, general statistical interpretation needs to account for multiplicity: the more tests conducted, the greater the chance that at least one result may appear notable by chance. A testing hierarchy, multiplicity adjustment, or prespecified distinction among confirmatory and exploratory analyses is not reported in the registry record.

The record lists no analyses. It therefore does not identify which outcomes were analyzed, what statistical tests or models were used, or how repeated measurements were handled. It does not report adjusted or unadjusted estimates, uncertainty intervals, or significance tests for the primary or secondary outcomes. The absence of analyses in the registry record should not be taken as evidence that no analyses were done elsewhere; it means that the registry entry does not report them.

Missing-data handling is also not reported in the registry record. The safety population is defined as participants who received a study device and had data collected for the specified timeframe, but the entry does not give visit-specific participant counts, reasons for missing measurements, imputation procedures, or sensitivity analyses. The definition of the safety population does not establish which participants were included in each outcome analysis.

In general, missing observations can affect interpretation when the availability of data is related to participants’ outcomes. Without follow-up completeness and a stated analysis approach, the extent and direction of any such influence cannot be assessed. The registry does not report interim analyses, stopping rules, or other monitoring procedures, so those aspects should not be assumed.

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: cataract (4.2%), muscle/tendon damage (2.8%), pain (2.8%), nerve damage (1.5%), unspecified heart problem (1.5%).

The registry reports serious adverse-event counts by device arm. For HEALICOIL Knotless PEEK, 66 participants were at risk for serious adverse events and 6 were affected; 66 were at risk for other adverse events and 14 were affected. The recorded number of deaths is 0. For HEALICOIL Knotless REGENESORB, 72 participants were at risk for serious adverse events and 14 were affected; 72 were at risk for other adverse events and 32 were affected. The recorded number of deaths is 0.

These are descriptive counts. They do not establish that the arms are comparable, since the registry states that the study was not randomized and that the arms are not a like-for-like control comparison. The record does not report a statistical comparison or confidence intervals for these figures. It also does not state whether participants could be counted in more than one adverse-event category, or provide enough information to compare observation time.

The registry lists selected serious-event terms with percentages: CATARACT, 4.2%; MUSCLE/TENDON DAMAGE, 2.8%; PAIN, 2.8%; NERVE DAMAGE, 1.5%; UNSPECIFIED HEART PROBLEM, 1.5%; and BONE FRACTURE(S), 1.5%. Arm attribution for these terms is not reported in the registry record. These percentages should not be converted into counts or assigned to a device arm without further information. The entries describe recorded safety events; they are not, by themselves, evidence that a device caused an event.

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

The registry record establishes that a completed post-market follow-up study evaluated two HEALICOIL Knotless suture anchor variants in shoulder rotator cuff tendon repair. It records enrollment of 138, names clinical success at 6 months as the primary outcome, and lists later clinical-success follow-up alongside shoulder function, pain, and quality-of-life measures. It also reports descriptive adverse-event counts for the two device arms.

Those details do not establish the primary clinical outcome. A numerical 6-month success result, its uncertainty, and an analysis are not reported in the registry record. The description defines repair failure in terms of a second repair procedure but does not give the number of participants experiencing that event or the precise rule translating failure into the clinical-success result. Consequently, the entry cannot show how often the primary outcome occurred or how precisely it was estimated.

The adverse-event counts can be read as recorded numbers of affected participants in the specified categories. They should not be read as a causal comparison. Allocation is not stated, the study was not randomized, and the record explicitly cautions that the arms are not like-for-like controls. The registry does not report an adjusted analysis that might address differences between groups.

In general, a study’s completed status and stated objective are distinct from its posted results. A list of outcomes indicates what was tracked or intended for assessment; it does not reveal the values observed. Likewise, an adverse-event count does not alone quantify comparative risk or identify cause. The record does not report numerical findings for the secondary measures, missing-data procedures, or analyses, so those aspects cannot be evaluated from this entry.

The appropriate reading is therefore limited: the registry describes the follow-up study and some safety observations, while leaving the primary and secondary clinical outcome findings unreported. It does not support a conclusion about the relative performance of the device variants or a claim that either does or does not work.

14. Why This Trial Matters Statistically

This study is statistically notable because its registry entry separates a clearly named clinical question from the evidence available to answer it. The primary endpoint is clinical success at 6 months, linked to repair failure and a subsequent repair procedure. Yet the registry record does not report the numerical endpoint result or an analysis. That distinction matters: an endpoint definition describes what a study intends to measure, while a result is needed to estimate how often the outcome occurred and with what precision.

The study also illustrates why design features govern interpretation. The registry names two device arms but states that allocation was not reported, the comparison was not randomized, and the arms are not like-for-like controls. In general, randomization helps balance measured and unmeasured characteristics across comparison groups. Without it, observed arm differences can reflect group composition or other factors, so simple contrasts cannot be treated as causal effects.

The record’s safety counts provide a different kind of information from an outcome analysis. They describe participants recorded as affected in adverse-event categories, but do not provide uncertainty intervals or an inferential comparison. Counts are useful for describing what was recorded; they do not, by themselves, show whether differences are statistically precise or attributable to a device.

The listed secondary measures also show that clinical follow-up can involve multiple dimensions, including function, pain, and quality of life. General statistical practice considers how multiple outcomes and missing observations affect interpretation. However, the registry record does not report a multiplicity plan, analysis methods, or missing-data handling, so those features cannot be assessed for this study.

For biostatisticians and clinical researchers, the central lesson is to distinguish study purpose, design, outcome definitions, and posted findings. A completed record with detailed outcome names may still lack the estimates needed for statistical conclusions. Here, the registry supports a description of the design and reported safety entries, but not an assessment of clinical outcome magnitude, precision, or comparative 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 most direct limitation of the registry entry is that it does not report numerical results for the primary endpoint, clinical success rate at 6 months, or analyses of that endpoint. It also does not report numerical results for the listed secondary outcomes. This prevents assessment of outcome frequency, uncertainty, and change over follow-up from the registry record.

The definition of the primary outcome is brief and potentially difficult to interpret without additional operational detail. It describes clinical success by reference to repair failure and defines failure as a need for a second procedure involving the original rotator cuff and/or biceps tenodesis from the index procedure. The registry does not report the exact coding rule for converting that failure definition into the titled success-rate measure, or explain how events outside the stated follow-up were handled.

The comparison has important design limitations. The registry states that allocation was not stated, that the study was not randomized, and that the arms are not a like-for-like control comparison. Any difference in descriptive outcomes between the device groups would therefore be open to confounding and cannot be interpreted as a causal effect from the registry entry alone. The record does not report an adjusted comparative analysis.

Additional study details needed to assess potential bias are not reported in the registry record, including participant eligibility criteria, site count, participant flow by visit, follow-up completeness, and reasons for missing observations. The record also does not describe the analysis population for each endpoint, methods for missing data, multiplicity procedures, or statistical models. The serious-event term percentages are not attributed to an arm in the entry, limiting their interpretation alongside the arm-level counts.

These limitations concern what can be learned from the registry record; they do not establish that the study lacked additional documentation or analyses. They do mean that the registry entry alone cannot support a precise estimate of clinical success or a comparative conclusion about the device variants.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Safety of Treatment of Shoulder Repair — NCT04552119.
• Registry record last updated 2026-04-16; status last verified 2024-11.
• Results first posted 2026-04-16.
• 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 describes a completed, prospective, multi-center, post-market clinical follow-up study of HEALICOIL Knotless PEEK and HEALICOIL Knotless REGENESORB for shoulder rotator cuff tendon repair. Enrollment was 138. The recorded start date is 2021-01-26, and the primary completion date is 2024-05-24. The sponsor is Smith & Nephew, Inc.

Clinical success rate at 6 months is the primary outcome. The registry links success to repair failure, defined as the need for a second repair procedure involving the original rotator cuff and/or biceps tenodesis from the index procedure. Listed secondary outcomes include later clinical success, shoulder function and pain scores, a shoulder self-assessment scale, and quality-of-life measures.

The registry reports adverse-event counts by arm, including serious events, other events, and deaths, and lists selected serious-event terms with percentages. It states that the comparison was not randomized, allocation was not stated, and the arms are not like-for-like controls. Numerical results and analyses for the primary and secondary outcomes are not reported in the registry record.