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 PRP vs Corticosteroid in Baker's Cyst (NCT02249377), a randomized phase 3 study. The primary outcome is Outcome of Baker's Cysts With the Use of Platelets-Rich-Plasma Versus Corticosteroid.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02249377 |
| Phase | Phase 3 |
| Condition | Baker's Cyst |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 50 |
| Arms in the primary outcome | n/a |
| Lead sponsor | NYU Langone Health |
| Results posted | Yes |
2. Clinical Question
Population
The planned population was patients with symptomatic Baker’s cysts. The brief summary describes follow-up after aspiration and lists 25 patients in each group. The registry record does not report participant characteristics or how many people actually received an intervention.
Intervention
The intervention was ultrasound-guided platelet-rich-plasma injection. The arm description also mentions instructions about anti-inflammatory medication, fasting, and drawing venous blood. The description is incomplete in the registry record, and no further procedural detail should be inferred from it.
Comparator
The comparator was ultrasound-guided aspiration and corticosteroid injection. The arm description names triamcinolone, lidocaine without epinephrine, and ropivacaine. The registry record also describes anti-inflammatory medication instructions and says fasting was not required for this group.
Primary question
The planned comparison concerned clinical outcomes at 6 Months. The registry describes assessment with the Visual Analogue Score, the Rauschning and Lindgren criteria, and the Knee Injury and Osteoarthritis Outcome Score. These measures address pain, cyst-related clinical features, and knee-related outcomes. No results are available to answer whether the groups differed.
3. Trial Design
The registry identifies this as a Phase 3, randomized, parallel-group study with no masking. It compares platelet-rich-plasma injection with corticosteroid injection in patients with symptomatic Baker’s cysts. The registry records an enrollment of 50 and the study summary describes 25 patients in each group. Those figures describe the record and its planned groups; they do not establish how many participants were enrolled, treated, or followed before the study ended.
The study was prospective according to its brief summary. The stated follow-up time points were 3 months and 6 months after aspiration, while the primary outcome timeframe is recorded as 6 Months. The registry lists recurrence of Baker’s cysts, complications, and side effects as secondary outcomes. It records four outcome measures in total, but no study analyses.
The record gives a study start of 2014-02 and a primary completion date of 2017-04-01. Its status is TERMINATED. The primary outcome description states that the study was terminated due to lack of funding, and that efforts to collect data were unsuccessful. No study data are available.
Randomization is the stated method for allocating patients to groups, but details such as the randomization sequence and allocation concealment are not reported in the registry record. Masking is explicitly listed as none. The registry record does not report additional design details that would establish how treatment delivery, outcome assessment, or follow-up were managed. In the absence of results, the design describes the intended comparison, not a completed comparison of observed 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 | Platelets-Rich-Plasma Group | Corticosteroid Group: |
|---|---|---|
| STARTED | 25 | 25 |
| COMPLETED | 0 | 1 |
| NOT COMPLETED | 25 | 24 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated due to lack of funding. Efforts were made to collect data, but were unsuccessful. No study data are available.
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: Study terminated due to lack of funding
| Characteristic | Unit | Platelets-Rich-Plasma Group | Corticosteroid Group: | Total |
|---|---|---|---|---|
| Participants analysed | 0 | 1 | 1 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 1 | 1 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 0 | 1 | 1 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Outcome of Baker's Cysts With the Use of Platelets-Rich-Plasma Versus Corticosteroid, measured over 6 Months.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is described as the outcome of Baker’s cysts with platelet-rich plasma versus corticosteroid, assessed at 6 Months. It uses the Visual Analogue Score (VAS), the Rauschning and Lindgren criteria, and the Knee Injury and Osteoarthritis Outcome Score (KOOS). The registry says the first two are used to clinically evaluate the presence of popliteal cysts, pain, posterior sense of tension in the popliteal fossa, and the clinical importance of reduced range of motion. KOOS is described as assessing short- and long-term outcomes of knee-related conditions.
These measures address different aspects of the clinical picture rather than a single identical quantity. In general, using patient-reported and clinical measures can describe symptoms and functional effects from more than one perspective. A score’s interpretation depends on its scoring rules, direction, and the way it is analyzed; those details are not reported in the registry record. The registry does not specify which measure would determine the primary statistical comparison, how scores would be summarized, or how changes over time would be evaluated.
No endpoint measurements or group results are available. Consequently, the named instruments identify what the study intended to assess, but they cannot establish what participants experienced or whether outcomes differed between groups.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a randomized comparison of platelet-rich-plasma injection and corticosteroid injection, but it reports no study data. The primary outcome description says that data-collection efforts were unsuccessful after the study was terminated due to lack of funding. As a result, there is no observed estimate of the difference between groups, no measure of its uncertainty, and no statistical test result to interpret.
The record lists zero participants at risk and zero events in its adverse-event entries for both groups. Those entries should not be interpreted as evidence that no adverse events occurred. The same record states that no study data are available, and it does not provide a participant accounting that would establish whether anyone was exposed to either intervention or followed for safety. The zeros are registry entries, not a supported safety comparison.
Likewise, enrollment of 50 and the summary’s plan for 25 patients in each group do not show that those numbers were enrolled or analyzed. The record does not report group-specific numbers randomized, treated, or assessed at follow-up. It also does not report outcome distributions, missingness by measure, or results for recurrence, complications, and side effects.
Without observed outcomes, there is no basis in this record for estimating an effect, judging its precision, or deciding whether a difference would be clinically meaningful. A p-value cannot be interpreted because no analysis result is reported. A confidence interval cannot be interpreted because no interval or underlying outcome estimate is available. These are absences of evidence in the registry record, not evidence that the interventions had identical outcomes.
There are also no analyses from which to assess whether randomization produced comparable groups, whether follow-up differed by group, or whether any outcome analysis accounted for repeated measurements. The registry does not report an analysis population or a statistical analysis plan. The trial’s stated status and lack of outcome data therefore limit interpretation to the study’s intended design and its termination, rather than a comparison of clinical results.
Any planning illustration based on an observed effect would require an observed effect estimate. Since none is available, no such illustration can be grounded in the study’s results. Planning quantities, where discussed, are not observed trial findings or evidence of power achieved.
9. Statistical Methods Explained
Statistical interpretation usually begins by identifying the outcome, the groups being compared, and the population included in the analysis. The registry names platelet-rich plasma and corticosteroid as the two interventions and describes a randomized, parallel-group comparison. It does not report an analysis population, participant flow, or outcome data. Thus, the intended comparison can be described, but an effect estimate cannot be reconstructed from the record.
What would an effect estimate describe?
In general, an effect estimate summarizes the contrast between groups for a specified outcome. For a score-based endpoint, the meaning of that contrast depends on how the score is defined, whether the analysis compares follow-up values or changes from baseline, and how repeated measurements are handled. The registry record names VAS, Rauschning and Lindgren criteria, and KOOS, but it does not report the planned score summaries or the primary contrast. There are no posted group values from which to estimate any contrast.
A confidence interval, in general, describes the range of effect estimates compatible with the data and the assumptions of the statistical method. Its width conveys precision: an interval that spans a broad range is less precise than a narrow one. No estimate or confidence interval is reported for this study, so the precision of a treatment comparison cannot be assessed. A p-value, in general, measures how unusual data would be under a specified null model; it does not measure the size or clinical importance of an effect. No p-values or inferential results are reported.
Why does the endpoint structure matter?
The primary outcome description includes several instruments and several clinical features. The registry record does not reduce these to one reported comparison, and the analysis listing contains no analyses. Different instruments may have different scales and interpretations. In general, a statistical analysis must specify which outcome or contrast answers the primary question and how each measure is represented. Without that information and without observations, no single numerical result can stand for the full endpoint description.
The study summary describes follow-up at 3 months and 6 months after aspiration, and the primary outcome timeframe is 6 Months. In general, repeated assessments from the same participant are related rather than independent. An analysis of multiple time points may need to account for that within-person relationship. The statistical model, handling of repeated observations, and any comparison of change over time are not reported in the registry record. It would be inappropriate to assume that a particular model or analysis was used.
How should the randomized design be understood?
Random allocation is intended, in general, to reduce systematic differences between groups at the point of assignment. It does not guarantee that groups will be identical, especially in a small study, and it cannot prevent bias arising after assignment through differences in treatment, follow-up, or outcome measurement. The registry identifies randomization and no masking, but details of sequence generation and allocation concealment are not reported in the registry record. There are no baseline data or follow-up results with which to examine group comparability or post-randomization differences.
The study is listed as unmasked. In general, lack of masking can matter when people’s knowledge of treatment assignment could influence care, reporting, or assessment. The registry record does not say whether outcome assessors were masked separately, or how outcomes were collected. No conclusion about the presence or direction of any resulting bias can be drawn without those details and the data.
What does the planning information mean?
The registry’s sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. They also state that the effect to detect is a stated fraction of the observed effect, and distinguish participants per arm for non-time-to-event outcomes from total events for time-to-event outcomes. These are general planning assumptions, not evidence about the trial’s actual analysis or achieved statistical power.
Here, no observed effect is available because no study data are reported. Therefore, planning illustrations based on an observed effect cannot be interpreted as estimates anchored to this trial’s results. Enrollment of 50 and the summary’s intended group sizes do not establish that the study had a particular probability of detecting an effect. Sample-size planning and observed power are different concepts; neither can substitute for an outcome estimate and its uncertainty.
The registry record does not report a protocol-based sample-size justification, a prespecified analysis plan, interim analyses, or details of any model. No such methods should be inferred from the planning assumptions or the randomized design alone. The central statistical limitation is that no observations or analyses are available to connect the intended design to a treatment-effect estimate.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome description includes multiple instruments and clinical features, and the study also lists secondary outcomes for recurrence of Baker’s cysts, complications, and side effects. When a study tests multiple outcomes or comparisons, multiplicity can increase the chance of obtaining at least one apparently unusual result by chance. In general, a prespecified hierarchy or adjustment strategy can clarify how multiple tests are interpreted. The registry record does not report a multiplicity plan, a hierarchy among the listed measures, or which measure would serve as the primary statistical comparison.
The registry lists four outcome measures but no analyses. The primary outcome description states that data-collection efforts were unsuccessful and that no study data are available. It does not report participant-level missingness, the number assessed at each follow-up, reasons for missing outcome measurements by group, or methods for handling missing data. It is therefore not possible to assess whether missingness differed between groups or how it might affect an estimate.
The record also does not report an intention-to-treat, per-protocol, or other analysis population. It is not possible to establish who was randomized, treated, or included in an analysis. The adverse-event entries contain zeros for participants at risk and events, but the absence of study data means those entries cannot establish complete safety follow-up or absence of events. These gaps prevent evaluation of the planned multiplicity, missing-data, and analysis-population decisions.
11. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, unmasked, parallel-group study was intended to compare platelet-rich-plasma injection with corticosteroid injection for symptomatic Baker’s cysts. It also records that the study was terminated due to lack of funding and that efforts to collect data were unsuccessful. Those details describe the study’s status and intended question, not its clinical findings.
There is no reported estimate for VAS, the Rauschning and Lindgren criteria, or KOOS, and no reported comparison at the primary outcome timeframe of 6 Months. There are no reported results for the secondary outcomes of recurrence, complications, or side effects. Because no data are available, the record cannot show whether the groups differed, how large any difference might have been, or how precisely an effect could be estimated.
Missing results should not be recast as a finding of no difference. A study that reports no outcome data has not established equivalence, noninferiority, benefit, or harm. Nor do the registry’s zero adverse-event entries establish that no adverse events occurred; the entries do not provide evidence of participants at risk or complete safety observation in a study with no available data.
The enrollment figure and intended allocation describe the registry record, not confirmed counts of participants analyzed. Likewise, the design and planned outcome measures do not establish that the study completed follow-up or implemented a particular statistical analysis. The appropriate interpretation is limited: the registry describes a planned randomized comparison, but it does not contain results with which to answer the clinical question.
12. Why This Trial Matters Statistically
This study matters statistically because it illustrates the difference between a randomized design and an interpretable randomized result. Randomization can support a fair comparison when allocation, follow-up, and outcome measurement are carried through and data are analyzed appropriately. But the design alone does not yield an effect estimate. The registry reports no study data, so readers cannot assess either the size or precision of a comparison.
The endpoint description also highlights the importance of specifying the primary contrast when several measures are named. VAS, the Rauschning and Lindgren criteria, and KOOS address related but distinct aspects of symptoms and knee-related outcomes. A clear analysis plan would ordinarily identify how these measures answer the primary question and how multiple outcomes are handled. Those decisions are not reported in the registry record, and no analyses are listed.
The termination due to lack of funding and unsuccessful data collection further shows why trial status and outcome availability must be considered together. A planned enrollment of 50 and intended equal groups do not ensure that a usable dataset exists. Without participant accounting, outcome observations, and analysis details, neither the planned design nor the planning assumptions can be used as a substitute for results.
For biostatistical interpretation, the key lesson is restraint: the record permits description of the intended comparison and its limitations, but not estimation of treatment effects or safety differences. Reporting the absence of data explicitly prevents an incomplete registry record from being mistaken for a negative finding.
13. 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 no study data are available. The registry states that the trial was terminated due to lack of funding and that efforts to collect data were unsuccessful. No primary or secondary outcome results are reported, and no analyses are listed. As a result, this record cannot support estimates of effect or precision.
The enrollment entry is 50, and the study summary describes 25 patients in each group, but the record does not report how many people were actually enrolled, randomized, treated, or assessed. It does not provide participant flow, baseline characteristics, or follow-up completion by group. The intended follow-up is described at 3 months and 6 months after aspiration, while the primary outcome timeframe is 6 Months; actual completion of those assessments is not reported in the registry record.
The primary outcome combines multiple measures and clinical features, without reporting a single statistical contrast, scoring details, or analysis method. Details of randomization sequence generation, allocation concealment, outcome-assessor masking, and the statistical analysis plan are not reported in the registry record. Multiplicity procedures and missing-data methods are also not reported in the registry record.
Finally, the adverse-event entries show zeros but do not report an evaluable safety population or completed follow-up. They cannot establish the absence of harms. These limitations are specific to the available registry information and prevent conclusions about efficacy, safety, or the precision of any group comparison.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: PRP vs Corticosteroid in Baker's Cyst — NCT02249377.
- Registry record last updated 2020-03-18; status last verified 2020-03.
- Results first posted 2020-03-18.
- 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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17. Record Summary
The registry describes a Phase 3 randomized, parallel-group study with no masking, comparing platelet-rich-plasma injection and corticosteroid injection for symptomatic Baker’s cysts. The record lists enrollment of 50; the brief summary describes 25 patients in each group. Planned follow-up was described at 3 months and 6 months after aspiration, with a primary outcome timeframe of 6 Months.
The primary outcome description names VAS, the Rauschning and Lindgren criteria, and KOOS. Secondary outcomes include cyst recurrence, complications, and side effects. The study status is TERMINATED. The registry says termination was due to lack of funding, data-collection efforts were unsuccessful, and no study data are available. It lists no analyses. Consequently, the record describes the intended trial question but does not report clinical or statistical results.