Percutaneous Interruption of the Coracohumeral Ligament for the Treatment of Frozen Shoulder: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Percutaneous Interruption of the Coracohumeral Ligament for the Treatment of Frozen Shoulder (NCT04549051), a randomized na study. The primary outcome is Comparison of Range of Motion of the Shoulder.

2. Clinical Question

In plain terms, the trial was designed to compare a procedure involving TENEX sectioning of the CHL plus local anesthetic with an initial local-anesthetic-only procedure. The stated primary outcome is short-term change in shoulder movement. The registry describes increased degrees of motion as a more favorable outcome, but it does not provide group means, standard deviations, confidence intervals, or a test result for the primary comparison. It therefore does not establish from the posted results whether the groups differed, or how precisely any difference was estimated.

The crossover option matters to the interpretation: the local-anesthetic group was not described as remaining on that treatment throughout follow-up. However, the primary measurement timeframe is immediately after the procedure, up to 60 minutes, while the stated crossover option begins at 1 month. The registry does not report the analysis population or explain how later crossover was handled in any outcome analysis. The secondary outcomes include ROM durability, pain intensity, and Oxford Shoulder Score changes for the groups, but numerical findings for those outcomes are not reported in the record details.

3. Trial Design

The registry describes a randomized trial with no masking and a crossover model. It was registered as a completed study, with enrollment listed as 46. The sponsor is Albert Einstein College of Medicine. The phase is listed as NA. The recorded start date is 2020-11-17, and primary completion is listed as 2022-03-16.

The trial compares TENEX device use for sectioning the CHL, alongside local anesthetic, with local anesthetic injected into the CHL alone. The local-anesthetic group had the option to cross over into the TENEX arm at 1 month. Thus, assignment was randomized, but the record does not describe masking; the listed masking is none. The crossover designation and the option to cross over indicate that treatment exposure could differ over time. The record does not report further details about the sequence, timing of assessments after crossover, or the analysis approach for data collected after crossover.

The primary outcome is a mean continuous measure: shoulder ROM, in degrees, measured with a goniometer. Its timeframe is immediately following the procedure, up to 60 minutes. The registry describes the outcome as change in ROM for external rotation and abduction and states that increased degrees of motion indicate a more favorable outcome. The wording also includes a threshold of at least 100%, but the record does not clarify how that threshold is applied to the measurement or comparison.

The registry lists 7 outcome measures and 0 analyses. The primary outcome was not reduced to a single comparison in the posted analysis because it has several categories or time points. Numerical results for the primary outcome are therefore not available in the registry record. A protocol, sample-size justification, detailed statistical plan, interim-analysis information, participant flow, baseline characteristics, and the handling of withdrawals are not reported in the registry record.

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.

First Intervention (4 Weeks)

Optional Second Intervention (11 Months)

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 Comparison of Range of Motion of the Shoulder, measured over Immediately following procedure, up to 60 minutes.

The primary endpoint concerns change in shoulder range of motion, measured in degrees with a goniometer. It includes external rotation and abduction and is assessed immediately following the procedure, up to 60 minutes. The registry describes an increase in degrees as a more favorable outcome. It also includes wording that the change in ROM is “by at least 100%,” but does not clarify how that criterion relates to the reported measurement or how the several ROM categories and time points were meant to be combined.

ROM is a continuous outcome: it can take a range of values rather than simply indicating whether an event occurred. In general, a mean summarizes the average measurement in a group, while a standard deviation describes how spread out individual measurements are around that mean. These summaries can help characterize both the average movement and the variability among participants. The registry identifies the planned summary as a mean with standard deviation, but does not report the group values for this primary endpoint.

The immediate assessment is intended to capture movement shortly after the procedure, not durability over a longer period. The registry lists durability of ROM as a secondary outcome, separately from the immediate primary timeframe. That distinction is important: an immediate post-procedure measurement cannot by itself describe whether a change persists. The record does not report numerical results for either the primary ROM outcome or the listed durability measures, so the endpoint definition alone cannot establish the size or precision of any observed change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary measure as continuous and states that it is summarized by a mean and standard deviation. These are descriptive statistics, not by themselves a comparison between randomized groups. A mean describes the average observed measurement; a standard deviation describes dispersion among measurements. To answer the comparative question, a report would ordinarily also need to present a contrast between groups, with an uncertainty measure and a clear account of which observations contributed to the analysis. Those comparative results are not reported in the registry record.

What does a confidence interval add?

In general, a confidence interval expresses the uncertainty around an estimated effect. It helps readers distinguish a precise estimate from one that could plausibly lie across a broad range. The interval does not show that every value in the range is equally likely, and it does not replace consideration of the study design or the quality of the data. For this trial, the registry does not report a confidence interval for the primary ROM comparison, so the precision of any group contrast cannot be assessed from the posted primary outcome information.

Why does the outcome definition matter?

The registry names external rotation and abduction, describes change in ROM, and gives the measurement unit as degrees. It also specifies immediate assessment up to 60 minutes and includes wording about a change of at least 100%. These details do not fully define a single analysis: the registry explicitly notes that the primary outcome has several categories or time points and was not reduced to one comparison. A statistical analysis needs to make clear which measurements are being compared, when they are measured, and how multiple components are handled. The record does not report that clarification or a numerical analysis.

In general, repeated measurements or multiple outcome components can create more than one possible comparison. If investigators select a result after examining several possible comparisons, the chance of a misleading positive finding can increase. Methods for addressing this issue depend on the planned questions and analysis. The registry record does not report a multiplicity strategy, a prespecified hierarchy, or an explanation for selecting a primary comparison beyond the outcome description. No conclusion about the use of such methods can be made from the absence of these details.

How should the crossover design be considered?

A crossover design allows treatment exposure to change over time for at least part of the study. Here, the local-anesthetic group had the option to cross over to TENEX at 1 month. For a comparison made immediately after the procedure, the recorded timeframe is earlier than that stated crossover option. For outcomes assessed later, however, interpretation would depend on whether measurements were made before or after crossover and on how the analysis accounted for treatment sequence and exposure. The registry does not report those details or any analysis results for later outcomes.

Random allocation can help make groups comparable at assignment, on average, when the study is conducted and analyzed appropriately. It does not ensure that all relevant characteristics are balanced in a particular trial, nor does the word “randomized” reveal the method used to generate or conceal assignments. The record identifies allocation as randomized but does not report the allocation-generation or concealment procedures. Masking is listed as none, so the record does not describe participants, clinicians, or outcome assessors as masked. For a goniometer-based measurement, assessment procedures and assessor expectations can matter; the record does not provide enough detail to assess how measurement was standardized or whether assessors knew treatment assignment.

What do the sample-size illustrations mean?

The posted planning illustrations are described as calculations based on the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. They are planning illustrations, not observed power and not a statement of the study's original design justification. The record does not report a protocol-based sample-size rationale. Because the primary numerical effect is not reported in the registry record, such illustrations should not be mistaken for evidence that the trial had adequate precision or that a treatment effect was established.

In general, a sample-size calculation depends on assumptions about the effect to detect, variability, allocation, and the chosen error rate. Changing an assumed effect changes the planning result. Calculations based on an observed estimate also inherit uncertainty from that estimate; they cannot retroactively show that a completed trial had a particular probability of detecting an effect. The record's description explicitly frames these outputs as planning illustrations rather than the trial's own design calculations.

What is not available for evaluating the analysis?

The registry lists 0 analyses and does not report the primary comparative estimate. It also does not report the analysis population, missing-data methods, treatment of protocol deviations, or a statistical plan. The record does not describe whether the primary comparison was intended to follow randomized assignment or another approach. These are not minor reporting details: they determine which data are analyzed and what the resulting estimate represents. In the absence of these details, the outcome definition and design description should not be treated as a substitute for an analysis.

These statistical concepts are general explanations, not claims about procedures used in this trial. The registry record does not report whether particular inferential methods, adjustment procedures, or interim analyses were used. Those methods cannot be inferred from the fact that the trial was randomized, crossover, or completed.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome includes several categories or time points, and the registry indicates that it was not reduced to a single comparison. Multiple components can make interpretation difficult if the analysis does not specify which contrast is primary and how the other results are treated. In general, testing many comparisons without a plan can increase the chance of a false-positive finding. This is a general statistical concern, not a claim that a particular error occurred in this trial. A multiplicity plan, prespecified hierarchy, or adjustment method is not reported in the registry record.

The registry lists 7 outcome measures, including secondary outcomes for ROM durability, pain intensity, and Oxford Shoulder Score changes in the local-anesthetic and TENEX groups. Numerical findings and analysis details for these measures are not reported in the registry record. It is therefore not possible to tell whether all listed outcomes were analyzed, how their results were selected for reporting, or whether any adjustment across outcomes was planned.

Missing-data procedures and analysis populations are also not reported in the registry record. The record does not say how missing measurements, withdrawals, or protocol deviations were handled, nor does it state which participants were included in each analysis. These omissions matter because an analysis based on a subset of participants can differ in meaning from one that preserves randomized assignment. No particular analysis population or missing-data method should be assumed.

Similarly, the registry does not report interim analyses or the statistical plan. Their use or absence cannot be inferred. With no primary analysis results and no information about missingness or multiplicity handling, the reader cannot evaluate the robustness of a reported effect or whether all planned comparisons are represented. The appropriate conclusion is limited: these analysis details are not reported in the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: serious adverse event (13.3%).

The registry reports serious adverse events for the group labeled Tenex Plus Local Anesthetic Alone as 4 affected among 30 at risk. For the group labeled Local Anesthetic First Then Tenex Plus Local Anesthetic, it reports 0 affected among 16 at risk. The top serious term is listed as “Serious Adverse Event” at 13.3%. This label is generic in the record and does not identify a specific clinical event.

For other adverse events, the registry reports 1 affected among 30 at risk in the first group and 0 among 16 at risk in the second. Deaths are reported as 0 in both groups. These are descriptive registry counts. They should not be treated as a causal comparison or as proof that an event was or was not related to a procedure. The record does not report event timing, definitions beyond the broad classifications, severity details, attribution, or a statistical safety analysis.

The group labels also reflect different treatment sequences: the local-anesthetic group had the option to cross over to TENEX at 1 month. The record does not explain how adverse events were assigned when treatment exposure changed, or whether the at-risk counts correspond to the same exposure window for each group. Accordingly, the figures describe what the registry reports, while leaving important context for comparative safety interpretation unreported.

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

The registry record establishes that a randomized, unmasked crossover trial was conducted to study percutaneous interruption of the CHL for frozen shoulder. It identifies the procedures being compared, the immediate ROM outcome, and several secondary outcome topics. It also records completion and enrollment. These details clarify the research question and the intended short-term measurement, but they do not answer the comparative question by themselves.

The primary outcome is change in shoulder ROM in degrees, including external rotation and abduction, assessed immediately after the procedure up to 60 minutes. Increased degrees are described as more favorable. Yet no group means, standard deviations, estimated contrast, confidence interval, or significance test are reported for that outcome. The registry notes that the endpoint has several categories or time points and was not reduced to one comparison. Consequently, the posted record does not show the size, direction, or precision of a primary treatment contrast.

The registry's adverse-event counts are not substitutes for efficacy results, and they do not establish a comparative safety effect. They are descriptive figures with limited reported detail on event definitions, timing, and attribution. The crossover option further makes later exposure and outcome interpretation dependent on details that are not reported.

In general, a result can be informative even when it is uncertain, provided the estimate and its uncertainty are reported. Here, the absence of the primary numerical analysis means readers cannot judge whether the data favor either assigned approach, are consistent with little difference, or remain compatible with materially different effects. That is a limitation of what can be concluded from the registry record, not evidence that the trial found no effect.

The trial record therefore supports a careful description of the design and outcome definitions, but not a claim that TENEX does or does not improve ROM, pain, or shoulder scores. Nor does it establish that the approaches are equivalent. Such conclusions would require reported comparative estimates and enough analysis detail to understand their uncertainty and the participants and measurements included.

13. Why This Trial Matters Statistically

This trial raises a clinically focused statistical question: whether a procedure that sections the CHL using TENEX, alongside local anesthetic, produces a different short-term ROM result from local anesthetic alone. The randomized design is relevant because random allocation is intended to support a fair comparison of assigned approaches. The crossover option is also important, because it may alter treatment exposure for later outcomes and therefore affects how those outcomes should be analyzed and interpreted.

The endpoint illustrates why outcome specification is central to trial interpretation. ROM is continuous and measured in degrees, while external rotation and abduction represent separate movement components. The stated immediate timeframe is distinct from the listed durability outcomes. A clear report would need to identify the primary comparison and explain how the multiple components or time points contribute to it. The registry says that the primary outcome was not reduced to a single comparison, so its record leaves the central estimate unavailable.

The record also demonstrates the difference between design information and results. Randomization, enrollment, completion status, and a defined measurement do not reveal the observed effect or its precision. Without a comparative estimate and uncertainty interval, readers cannot determine what the trial's primary data show. The descriptive adverse-event counts add safety information, but not a causal comparison or a complete account of event attribution.

Statistically, the most important issue is therefore not a complicated model but incomplete reporting of the main comparison and its analysis. The listed sample-size illustrations are described as planning tools based on an observed effect, not as the trial's original justification or observed power. This distinction prevents retrospective planning calculations from being mistaken for evidence about the trial's ability to detect a clinically meaningful effect.

The trial matters as an example of why outcome definitions, crossover handling, missing-data procedures, and analysis populations need to be reported alongside numerical results. Without those elements, the record can describe what was intended but cannot support a precise conclusion about comparative effectiveness or safety.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record does not report numerical results for the primary ROM outcome. In particular, it does not give group means, standard deviations, a comparative estimate, a confidence interval, or a significance test. The record also notes that the outcome has several categories or time points and was not reduced to a single comparison. This prevents evaluation of the main trial question from the posted primary outcome information.

The endpoint description contains wording about a change in ROM “by at least 100%,” but does not explain how that criterion is operationalized. External rotation and abduction are both named, and the timeframe is immediate after the procedure, up to 60 minutes. The record does not clarify how measurements across components or time points were to be combined or prioritized.

The registry identifies a crossover model and states that the local-anesthetic group could cross over to TENEX at 1 month. It does not report the later assessment schedule, how crossover was handled in analyses, or how adverse events were attributed after treatment exposure changed. This is especially relevant to the listed durability and other secondary outcomes.

Masking is listed as none. The record does not say whether outcome assessors were aware of group assignment or how goniometer measurements were standardized. Allocation concealment and the randomization procedure are also not reported. These omissions limit assessment of potential influences on measurement and assignment.

The registry lists 7 outcome measures but 0 analyses. It does not report a statistical plan, analysis populations, missing-data procedures, withdrawals, baseline characteristics, or a protocol-based sample-size justification. The adverse-event information is limited to descriptive counts and a generic top serious-event term; definitions, timing, and attribution are not reported. These limitations restrict interpretation and should not be filled by assumptions about methods or results.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Percutaneous Interruption of the Coracohumeral Ligament for the Treatment of Frozen Shoulder — NCT04549051.
• Registry record last updated 2024-05-29; status last verified 2024-05.
• Results first posted 2024-05-29.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The record describes NCT04549051, “Percutaneous Interruption of the Coracohumeral Ligament for the Treatment of Frozen Shoulder,” sponsored by Albert Einstein College of Medicine. The condition is adhesive capsulitis. The study is listed as randomized, unmasked, crossover, and completed, with enrollment of 46. Its recorded start date is 2020-11-17, and primary completion is 2022-03-16.

The trial compares TENEX use for CHL sectioning plus local anesthetic with local anesthetic alone initially; the latter group could cross over to TENEX at 1 month. The primary outcome is shoulder ROM in degrees, measured with a goniometer immediately after the procedure, up to 60 minutes. Secondary outcomes include ROM durability, pain intensity, and Oxford Shoulder Score changes.

The registry lists 7 outcome measures and 0 analyses. The primary outcome was not reduced to one comparison because it includes several categories or time points. Numerical comparative results for the primary and secondary outcomes are not reported in the registry record. Descriptive adverse-event counts are reported, but event timing, attribution, and a comparative safety analysis are not.