An Evaluation of Rigid Sternal Fixation in Supporting Bone Healing and Improving Postoperative Recovery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for An Evaluation of Rigid Sternal Fixation in Supporting Bone Healing and Improving Postoperative Recovery (NCT01783483), a randomized na study. The primary outcome is Sternal Healing Score at 3 Month Post op, as Defined by a 6-point Scale to Evaluate Bone Healing.

2. Clinical Question

3. Trial Design

This was a prospective, randomized, parallel-group trial comparing two methods of sternal closure after full median sternotomy. The registry lists the trial as single-masked, but does not identify which participants or study personnel were masked. The phase is listed as not applicable. The study enrolled 236 participants and is recorded as completed. The start is listed as 2013-01 and the primary completion as 2015-06.

The sponsor was Zimmer Biomet. The two study arms were Suture Wire and the SternaLock Blu Closure System. In the wire arm, the surgeon and institution could determine the wiring configuration within the stated minimum-wire requirement. In the device arm, the description specified a standard plate configuration. The registry does not report the actual allocation sequence, allocation concealment procedures, or whether enrollment and treatment assignment followed equal allocation.

The primary outcome was the mean sternal healing score at 3 months postoperatively. The primary endpoint population consisted of participants with completed CT scans at that time point: 102 in the wire arm and 103 in the device arm. Those endpoint counts should not be confused with the total enrollment. The record does not report the reasons participants lacked a completed CT scan or the analysis population used for other outcomes.

Additional outcomes were intended to cover postoperative pain at several follow-up times, narcotic use, patient function, quality of life, complications, and health economics. The registry lists pain assessments at Day 7, 3 weeks, 6 weeks, 3 months, and 6 months, as well as narcotic-use outcomes. The numerical results available for those secondary outcomes are incomplete in the registry record. The record also does not report the trial’s original sample-size justification, detailed protocol, or full prespecified statistical analysis plan.

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: Subjects with completed CT scan at 3 month post op: 102 Suture Wire / 103 SternaLock Blu

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 Sternal Healing Score at 3 Month Post op, as Defined by a 6-point Scale to Evaluate Bone Healing, measured over 3-month post-op.

The primary endpoint was the sternal healing score at 3 months after surgery, assessed among participants with a completed CT scan. The registry defines a six-point scale ranging from 0 to 5. A score of 0 describes nonunion, with no contact between the sternal halves and other signs of poor healing. Scores 1 and 2 represent indeterminate findings or early healing. Score 3 represents mild synthesis, with bridging bone along less than half of the anteroposterior dimension. Score 4 represents moderate synthesis, with bridging bone along at least half of that dimension. The registry identifies well-aligned sternal halves as the best outcome, at score 5. In this scale, higher scores therefore indicate more favorable bone-healing findings.

A CT-based scale offers a structured way to summarize the extent of bone bridging and alignment rather than relying only on a broad clinical impression. The reported endpoint is a mean score, so the group summaries describe average scores across participants; they do not show how many participants had each individual score. The record does not report the score distribution, the scoring assessor, or procedures for resolving disagreement between assessors. Nor does it state the minimum score difference considered clinically important. The endpoint speaks specifically to radiographic healing at the 3-month assessment and is not a direct measure of pain, function, quality of life, or complications.

7. Results Posted in the Registry

• SternaLock Blu Closure System: mean 2.60 versus 1.80 on control; difference 0.80 (95% CI 0.51 to 1.09), standardized effect d = 0.76; z-test p = <0.001.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Narcotic Usage

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • SternaLock Blu Closure System: mean 93.73 versus 72.75 on control; difference 20.98 (95% CI -24.77 to 66.73), standardized effect d = 0.12; z-test p = 0.369.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between SternaLock Blu Closure System and the control. The interval gives the range of effects that remain compatible with the data.

The registry’s planned secondary outcomes include pain scores at several postoperative assessments, narcotic use, function, quality of life, complications, and health economics. The posted quantitative secondary result available in the registry record concerns narcotic usage from Day 0 to hospital discharge. A complete numerical pattern across the pain assessments and other listed domains is not reported in the registry record, so those outcomes cannot be synthesized into a broad account of postoperative recovery.

The available narcotic-use comparison is less conclusive than the primary healing comparison: its confidence interval includes zero and the unadjusted p-value is 0.369, while the sponsor-reported two-sided test gives p = 0.370. This result does not establish a clear difference between the groups in narcotic use during the stated period. It also does not establish equivalence; uncertainty remains, and the reported variability is substantial relative to the group means.

These secondary findings address a different outcome from CT-based healing. A result for narcotic use cannot confirm or refute the radiographic finding, and the primary result cannot be assumed to predict pain, function, quality of life, or cost. The registry lists these as separate areas of interest, but the reported results are not complete enough to describe a unified recovery pattern.

Multiplicity matters because several outcomes and follow-up times were contemplated. In general, examining many outcomes can increase the chance of a seemingly notable result arising by chance. The registry record does not report whether secondary analyses were prespecified in a hierarchy or adjusted for multiple comparisons. Secondary results should therefore be treated as supportive or exploratory rather than given the same evidential weight as a clearly specified primary analysis. The missing numerical results also prevent assessment of consistency across follow-up times.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Pain Measured in a 10-point Scale at Day 7 Post Operative
• Pain Measured in a 10-point Scale at 3-week Post Operative
• Pain Measured in a 10-point Scale at 6-week Post Operative
• Pain Measured in a 10-point Scale at 3-month Post Operative
• Pain Measured in a 10-point Scale at 6-month Post Operative
• Narcotic Usage
• Narcotic Usage
• Narcotic Usage

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is continuous in the analysis because the registry reports a mean score and standard deviation for each arm. The score itself is built from ordered categories: higher scores correspond to progressively more favorable descriptions of healing. Reporting a mean gives a compact comparison between groups, but it does not preserve the full ordinal distribution. Two groups can have the same mean while differing in how their participants are distributed across score categories. The registry record does not report category counts or an alternative ordinal analysis.

What does a mean difference represent?

The posted mean difference compares the average score for the SternaLock Blu group with the average for the Suture Wire group. The group means are 2.6 and 1.8, respectively, and the reported mean difference is 0.8 units. Because the score is higher for more favorable healing descriptions, a positive mean difference corresponds to a higher average score in the device arm. This is a group-level contrast: it does not mean that each participant’s score differed by the same amount.

The standard deviations describe the spread of scores around the group means. The posted standard deviations are 1.1 for SternaLock Blu and 1.0 for Suture Wire. They are not confidence intervals and do not directly give the precision of the estimated difference. Precision also depends on the number of analyzed participants in each arm. The primary CT population was 103 in the device group and 102 in the wire group.

What does the t-test assess?

The registry reports a two-sided t-test for the primary comparison. In general, a two-sided test evaluates evidence against equal group means in either direction, rather than testing only whether one prespecified arm has a higher mean. A t-test expresses how compatible the observed difference is with a model in which the group means are equal, subject to the test’s assumptions. A small p-value is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of the difference.

The registry’s own primary analysis reports p < 0.001. The unadjusted recalculation from the posted summary statistics reports p < 0.001. The recalculation uses the arm means, standard deviations, and sample sizes and does not reproduce an adjusted model or an analysis using participant-level data. The registry record does not report whether the sponsor’s analysis used any additional covariates or other adjustments.

Why does the scale matter?

The score is a six-point scale with clinically described categories, but the primary summary treats it through its mean. In general, means are easiest to interpret when the numerical steps between scale values can be treated as comparably spaced. The descriptions establish an ordering from nonunion toward well-aligned sternal halves, but the registry does not report evidence about whether the distance between adjacent score categories is equivalent. A reader can interpret the direction of higher scores from the definitions, while recognizing that the mean compresses a set of ordered categories into one summary.

The scale’s endpoint is also specific to a CT assessment at 3 months. It does not directly measure symptoms or later recovery. In general, an outcome can be statistically distinguishable between groups without demonstrating that the difference changes a patient-important experience. The record does not report a threshold for a clinically meaningful difference on this scale, so the magnitude should be read as a difference in mean scale units rather than translated into a clinical benefit threshold.

What role does the confidence interval play?

A confidence interval describes a range of effect estimates compatible with the data and the method used, under the method’s assumptions. It communicates uncertainty around the estimated mean difference and is more informative about precision than a p-value alone. The primary interval is entirely above zero, while its exact confidence level is not identified in the registry’s reported analysis details. The level and construction of the interval should therefore not be inferred beyond what the record states.

In general, confidence intervals are sensitive to the analysis population and assumptions. The primary endpoint is based on completed CT scans, and the record does not describe missing-data methods or a sensitivity analysis. The interval summarizes uncertainty for the analyzed group comparison; it cannot account for possible bias caused by missing outcomes unless that issue is addressed in the analysis.

What is and is not reported about the analysis plan?

The registry identifies the primary measure, its time frame, group summaries, and the sponsor’s two-sided t-test. It does not report the original sample-size justification, a detailed prespecified statistical plan, interim analyses, or multiplicity procedures. The record also does not identify the masked party or provide the full participant-level analysis population. These omissions limit assessment of whether the posted analysis exactly follows a prespecified plan or how all planned analyses were handled. The absence of reporting is not evidence that a procedure was or was not carried out.

In general, multiple endpoints or repeated assessments can create multiplicity: if many hypotheses are tested, the chance of at least one apparently notable result can increase. A prespecified hierarchy or adjustment can address that concern, but such procedures are not reported in the registry record. The primary endpoint should therefore be distinguished from the additional outcomes, for which the record does not provide a complete set of numerical findings.

11. Confidence Intervals and Precision

The primary mean difference is 0.8 units in favor of the SternaLock Blu group on the healing scale. The confidence interval for this estimate is entirely above zero, indicating that the reported interval does not include a zero mean difference. Its precise confidence level is not reported in the registry record, so the interval should not be assigned a conventional level based on assumption.

Precision concerns how much uncertainty surrounds an estimated effect, not whether an effect is important. The observed interval supports a positive difference in average scores under the analysis method, but the registry does not state what interval width or score difference would be clinically meaningful. The score categories range from nonunion to well-aligned sternal halves, but a clinical-importance threshold is not reported in the registry record.

The arm sizes for this endpoint are 102 and 103, drawn from participants with completed CT scans. The reported standard deviations are 1.0 and 1.1. These summaries help characterize the data used in the comparison, but they do not show the score distribution or address whether missing CT assessments could affect the estimate. No missing-data sensitivity analysis is reported in the registry record.

In general, an interval should be read with the estimate, outcome definition, and analysis population. A p-value alone cannot convey the range of plausible effect sizes, and an interval alone cannot resolve concerns about bias, measurement, or clinical meaning. Here, the interval’s position above zero and the positive mean difference give a consistent direction of statistical evidence, while the omitted details limit further judgments about precision beyond the analyzed CT-completer population.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size figures are planning illustrations based on the observed effect, not a reconstruction of the trial’s original design. The record’s stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to a stated fraction of the observed effect. For these continuous outcomes, the figures are participants per arm, not total events.

For the primary healing comparison, planning for 100% of the observed effect gives 28 participants per arm for 80% power and 37 participants per arm for 90% power. Planning for 75% of the observed effect gives 49 per arm for 80% power and 65 per arm for 90% power. Planning for 50% of the observed effect gives 109 per arm for 80% power and 146 per arm for 90% power.

The 80% power column means the planned sample size is calculated to give an 80% chance of detecting the specified effect under the stated assumptions; the 90% column uses a higher chance of detection and consequently requires more participants for the same assumed effect. These are prospective planning quantities, not observed power.

The relationship is important: smaller target effects require more participants. For the narcotic-use comparison, the planning figures are much larger because the observed effect and variability yield a different planning calculation. The registry’s original sample-size assumptions and justification are not reported, so these illustrative figures should not be interpreted as the trial’s enrollment target or as evidence about the design choices made when the study was planned.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 0.800; pooled standard deviation σ = 1.051.
2. n = 2 × (1.96 + 0.842)² × 1.051² / 0.800² = 27.1, rounded up to 28 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 0.8                      # observed difference in means
sigma <- 1.05143579993232                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1783483)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 28 (80% power), 37 (90% power)
 75% of observed effect: n per arm = 49 (80% power), 65 (90% power)
 50% of observed effect: n per arm = 109 (80% power), 146 (90% power)
power.t.test: 28.1 
Simulated power at n = 28 per arm: 0.800 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The registry reports the sponsor’s primary comparison as a two-sided t-test, with a p-value below the threshold represented by < 0.001. The simple unadjusted recalculation from the posted group means, standard deviations, and sample sizes gives p < 0.001. Both analyses indicate strong statistical evidence against equal group means, and both point in the direction of a higher mean healing score for the SternaLock Blu arm.

The recalculation is based only on posted summary statistics. It is not a substitute for the sponsor’s analysis, which may have used information or analytic details not represented in those summaries; the registry record does not report whether it did. The recalculation does not establish an adjusted effect or reproduce participant-level modeling. The sponsor’s reported p-value is more stringent than the recalculated threshold, but the registry does not provide enough detail to explain the difference in reported precision.

The sponsor’s result should be read as the trial’s own reported analysis, while the recalculation is a consistency check using unadjusted summaries. Neither p-value gives the probability that the observed effect is clinically important. The primary effect estimate and its interval, the scale definition, and the endpoint population remain essential to interpreting the result.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary healing endpoint and lists multiple secondary outcomes, including pain at repeated follow-up times, narcotic usage, patient function, quality of life, complications, and health economics. Multiple statistical tests can create multiplicity: in general, as the number of tests increases, the chance of obtaining at least one small p-value by chance can increase. Prespecifying a primary outcome and using an appropriate hierarchy or adjustment are common ways to manage this issue. The registry record does not report a multiplicity procedure, hierarchy for secondary outcomes, or family of hypotheses used for inference.

The trial is listed as single-masked, but the registry record does not identify who was masked or how masking was maintained. Randomization is reported, but the sequence-generation method and allocation concealment are not reported in the registry record. These details matter when assessing potential selection and measurement biases; their absence from the record does not establish whether the methods were or were not used.

The primary analysis population is defined as participants with a completed CT scan at 3 months: 102 in the wire arm and 103 in the device arm. Although total enrollment was 236, the registry does not report reasons for missing primary scans, the handling of missing scores, or a sensitivity analysis. The results therefore describe the CT-completer population, and the effect of missing endpoint data cannot be assessed from the posted information.

The original sample-size justification, detailed protocol, interim analysis plan, and full statistical analysis plan are not reported in the registry record. The record also does not report whether the primary analysis adjusted for covariates or whether any analyses were changed after data collection. Without these details, readers cannot fully assess prospective specification, handling of all planned tests, or analysis choices. The appropriate conclusion is limited to the outcomes and analyses actually reported.

16. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: deep sternal wound infection (dswi) (2.5%), bleeding requiring re-operation (1.7%), superficial sternal wound infection (sswi) (1.7%), other sternal wound complication (0.8%), stroke (0.8%).

The registry reports serious adverse events among 120 participants at risk in the Suture Wire group and 116 at risk in the SternaLock Blu group. Serious adverse events affected 10 and 2 participants, respectively. Other, non-serious adverse events were reported among 40 of 120 at risk in the wire group and 37 of 116 at risk in the device group. Deaths were reported for 3 participants in the wire group and 2 in the device group.

These are descriptive counts from the registry. They do not by themselves establish that the closure method caused an event or that the groups differ in risk. The registry also lists serious-event terms and percentages, including deep sternal wound infection at 2.5%, bleeding requiring re-operation at 1.7%, superficial sternal wound infection at 1.7%, other sternal wound complication at 0.8%, stroke at 0.8%, and acute renal failure at 0.8%. The record does not attribute each listed percentage to a particular arm in the information.

Safety comparisons require attention to event definitions, observation periods, participant exposure, and uncertainty. These details are not fully reported in the registry record, so the counts should not be treated as a definitive comparative safety analysis.

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

The primary result shows a higher average 3-month CT healing score in the SternaLock Blu group than in the Suture Wire group among participants with completed scans. The scale’s definitions place higher values toward more favorable bone-healing findings, and the reported mean difference is positive. The confidence interval is entirely above zero, and the registry’s two-sided test reports strong statistical evidence against equal group means.

This statistical result does not mean every participant in the device group had a better score than every participant in the wire group. It is a comparison of group averages, with variation within both arms. The record does not provide the individual score distribution or a threshold for a clinically meaningful score difference. Statistical evidence about a mean difference should not be equated automatically with a specific patient-level benefit.

The result applies to the CT-completer population at the 3-month assessment. The registry does not explain why the primary analysis includes fewer participants than were enrolled, or how missing scans were handled. The effect of missing outcomes on the estimate is therefore uncertain. The result also does not establish whether score differences persist at later times, because the primary endpoint is restricted to the stated follow-up.

The primary finding does not answer all questions raised by the trial. Pain, narcotic use, function, quality of life, complications, and health economics are distinct outcomes. The record does not report a complete numerical set of results across those domains. A primary healing-score difference should not be generalized to those outcomes without their corresponding evidence.

Overall, the posted data support a difference in mean radiographic healing scores in the analyzed groups, while leaving clinical importance, missing-data effects, longer-term outcomes, and the full recovery profile unresolved. This is a statistical interpretation of the registry record, not medical advice or a recommendation about treatment.

18. Why This Trial Matters Statistically

This trial illustrates how a clinical comparison can produce a clear difference in a primary endpoint while leaving important questions about the broader patient experience unanswered. The endpoint is a structured CT-based score with an explicit direction: higher values describe more favorable healing. That definition makes the direction of the mean comparison interpretable, while the mean summary still hides the distribution of individual scores.

The trial also demonstrates why estimates and uncertainty should be considered together. The posted mean difference and confidence interval communicate both the direction and the range of uncertainty for the analyzed comparison. The p-value addresses compatibility with equal group means under the test assumptions, but does not measure clinical importance. These statistical quantities answer related but distinct questions.

Its endpoint population highlights the importance of analysis populations and missing outcomes. Total enrollment was 236, whereas the primary endpoint uses participants with a completed CT scan. Without reasons for missing scans or sensitivity analyses, readers cannot determine whether the CT-completer comparison represents all enrolled participants. That limitation is separate from the strength of the statistical evidence within the analyzed sample.

Finally, a trial’s primary endpoint is only one part of its evidence. This study also intended to examine pain, analgesic use, function, quality of life, complications, and health economics, but the registry does not report a complete numerical account of those outcomes. Distinguishing a radiographic result from broader recovery claims is essential for precise interpretation. The record therefore offers a focused statistical comparison, while its incomplete reporting constrains conclusions about the full set of clinical questions.

19. 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 primary outcome is restricted to participants with a completed CT scan at 3 months, and the registry does not report why other enrolled participants are absent from that endpoint analysis. No missing-data strategy or sensitivity analysis is reported. As a result, the effect of missing primary outcomes on the comparison cannot be assessed.

The six-point scale is described in terms of healing categories, but the registry does not report score distributions, assessor training, assessor reliability, or whether CT assessments were masked. Means and standard deviations do not show how many participants fell into each category. The record also does not identify a clinically meaningful difference on the scale, limiting interpretation of the magnitude beyond its numerical direction.

The study is described as single-masked, but the masked party is not specified. The randomization method and concealment procedures are not reported in the registry record. The wire technique could vary by surgeon and institution within the stated minimum, but the actual distribution of techniques is not reported. These omissions restrict assessment of implementation and potential sources of variation.

Several additional outcomes were planned or listed, but the registry does not report a complete numerical set of results for pain, function, quality of life, complications, or health economics. Multiplicity handling, interim analyses, the original sample-size justification, and the full statistical analysis plan are also not reported. The endpoint is assessed at 3 months; longer-term primary healing results are not reported in the registry record. These limitations concern the information available for interpretation and should not be taken as evidence that unreported procedures or outcomes were absent from the full study.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: An Evaluation of Rigid Sternal Fixation in Supporting Bone Healing and Improving Postoperative Recovery — NCT01783483.
• Registry record last updated 2017-09-08; status last verified 2017-08.
• Results first posted 2017-09-08.
• 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.

23. Record Summary

NCT01783483 is a completed prospective, randomized, parallel-group trial sponsored by Zimmer Biomet. It compared SternaLock Blu closure with suture wire after full median sternotomy. The registry reports 236 enrolled participants and a primary endpoint of mean CT-based sternal healing score at 3 months among participants with completed scans.

The mean score was 2.6 for SternaLock Blu and 1.8 for Suture Wire, with a reported mean difference of 0.8 units and a confidence interval entirely above zero. The sponsor’s two-sided test reports p < 0.001. The registry also reports selected secondary and adverse-event results, but a complete numerical account across the planned recovery outcomes is not reported in the registry record. Details about the original sample-size justification, missing primary scans, and multiplicity procedures are not reported in the registry record.