Computer Assisted Planing of Corrective Osteotomy for Distal Radius Malunion: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Computer Assisted Planing of Corrective Osteotomy for Distal Radius Malunion (NCT01193010), a randomized na study. The primary outcome is Disability of the Shoulder and Hand Score.

2. Clinical Question

3. Trial Design

The registry record describes a randomized, parallel-group, multicenter controlled trial. Participants were assigned to corrective osteotomy with computer-assisted preoperative planning or to corrective surgery without computer-assisted planning. The record lists the study as completed and gives an enrollment of 40. It does not provide the number who completed follow-up or the number included in each outcome analysis.

The stated clinical context is symptomatic extra-articular distal radius malunion. Both groups received corrective surgery; the randomized contrast was the planning approach. This distinction matters when interpreting the study question: the design compares ways of planning an operation, not surgery against no surgery. The registry describes the computer-assisted approach as involving preoperative planning and virtual osteotomy. It describes the control as surgery without computer-assisted planning, but gives no further protocol details for either surgical pathway.

The registry lists masking as none. Thus, the record does not describe masking of participants or study personnel. It does not report whether outcome assessors were masked. Random allocation can help balance measured and unmeasured baseline characteristics on average, but it does not ensure that groups are identical, particularly in a trial of this size. No baseline characteristics or allocation details are reported in the outcome information.

The primary outcome is DASH, a continuous measure of upper-extremity function, with follow-up times listed at 0, 3, 6, and 12 months. Other listed outcomes are the Patient-Rated Wrist Evaluation, a numerical pain rating scale, and a numerical satisfaction rating scale. The registry record does not give the results for these outcomes. It also does not report the randomization method, concealment procedures, center-specific enrollment, protocol deviations, or follow-up completion by group.

The registry lists a primary completion date of 2016-05 and a completed status. Completion status alone does not supply evidence about the outcome contrast. Without group-specific outcome estimates and a defined analysis, the design can be described, but the comparative effect cannot be assessed from 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.

Overall Study

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: Adult patients electing for corrective osteotomy for symptomatic extra-articular distal radial malunion.

6. Primary Endpoint

The registry lists the primary outcome as Disability of the Shoulder and Hand Score, measured over 0, 3, 6, 12 months.

The primary endpoint is the Disability of the Shoulder and Hand Score, abbreviated DASH. The registry describes it as a measure of upper-extremity function, recorded in units on a scale. Its stated range is 0-100, with higher scores indicating more disability and worse upper-extremity function. It is therefore a patient-function measure in which the direction of the scale is important: a lower score corresponds to less reported disability, while a higher score corresponds to worse function.

A functional measure is relevant to this trial because the stated hypothesis concerns functional outcome following corrective surgery planned with or without computer assistance. The score can capture a patient's reported experience of upper-extremity limitation rather than only a technical or radiographic feature of the operation. The registry record does not give further detail on the questionnaire administration, scoring rules, or interpretation of changes in score.

DASH measurements are listed at 0, 3, 6, and 12 months. These are repeated observations over follow-up, not a single value. The registry record does not identify one of these times as the sole primary comparison, nor does it report the group means, standard deviations, changes from baseline, or between-group estimates at any time. Consequently, the endpoint's definition and measurement schedule are available, but its observed results and their precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous and is described as a mean with standard deviation. A mean gives a measure of the central location of observed scores, while the standard deviation describes how spread out individual scores are around that mean. These summaries answer different questions: the mean describes an average score, and the standard deviation describes variability among participants. Neither is reported by group for DASH in the registry record, so neither the typical score nor its spread can be assessed from the posted outcome information.

A between-group estimate would express the contrast in DASH scores between the computer-assisted and conventional planning groups. Because higher DASH scores indicate worse function, the direction of such an estimate would need to be interpreted against that scale direction and against the stated comparison order. The registry record does not report an estimate, its direction, or the ordering used for a contrast. No difference should be inferred from the trial hypothesis or from the fact that the study is marked completed.

A confidence interval is a way of describing the statistical uncertainty around an estimated effect. In general, a narrower interval indicates greater precision, while a wider interval indicates less precision. An interval can also show which effect sizes remain compatible with the data under the assumptions of the analysis. No confidence interval for DASH is reported in the registry record, so the precision of the primary outcome comparison cannot be judged. A p-value, if reported, would address compatibility of the data with a specified null model; it would not by itself describe the magnitude or clinical importance of a difference. No p-value or test result is reported for the primary outcome.

Measurements at 0, 3, 6, and 12 months are repeated observations on participants over time. In general, scores from the same participant are related rather than independent. An analysis using all time points should account for that within-person relationship and specify what aspect of the trajectories is being compared. For example, one analysis might focus on a particular follow-up time, while another could compare patterns across follow-up. These are general methodological possibilities, not descriptions of the analysis used in this trial. The registry record does not report a model, a selected primary time point, or an analysis of trajectories.

The stated 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. The stated effect to detect is a fraction of the observed effect. These are planning assumptions, not evidence that the trial was designed using them, and they are not observed power. The registry record does not report its own sample-size justification or the effect estimate used for any planning illustration. It also does not report a protocol-based target difference or a precision target. Any sample-size illustration should therefore be read as hypothetical planning rather than as proof that the study had adequate power for its primary question.

Over-dispersion is a general concern when observed variability is greater than assumed by a statistical model. If a model understates variability, it can make standard errors too small and uncertainty appear less than it is. That concept is most directly relevant to models for counts or other outcomes with a specified variance structure; the registered primary endpoint is continuous. The record does not report a model or diagnostic assessment, so there is no basis to say whether over-dispersion was relevant to any analysis in this trial.

Randomization supports an unbiased comparison in expectation when the assigned groups are analyzed appropriately, but the statistical interpretation also depends on how participants are handled after assignment. An intention-to-treat analysis generally compares participants according to randomized group, while a per-protocol analysis may restrict the comparison to participants meeting specified conditions. This is a general distinction; the registry record does not state which analysis population was used. It also does not describe adjustment for baseline DASH, center, or other covariates.

Since there are several outcome time points and additional secondary outcomes, an analysis plan would ordinarily clarify which comparisons are confirmatory and how multiplicity is handled. Testing multiple outcomes or time points can increase the chance of at least one nominally notable result under a broad set of null hypotheses. Methods such as a prespecified hierarchy or adjustment can address that issue, but the registry record does not report such a plan or an adjustment. No recalculated primary estimate is available because the necessary group summaries are not reported. The record lists zero outcome analyses, so statistical significance, effect magnitude, and uncertainty cannot be evaluated for the primary endpoint.

10. Multiplicity, Missing Data and Analysis Populations

The registered primary outcome is measured at 0, 3, 6, and 12 months. The registry record does not identify one time point as the sole primary comparison, or explain whether the primary question concerns change from baseline, a particular follow-up measurement, or the overall pattern over time. Considering several time points can create multiple opportunities to observe a difference. In general, a prespecified analysis plan helps distinguish the main confirmatory comparison from exploratory comparisons and can specify how multiplicity is handled. Such a plan or method is not reported in the registry record.

Three secondary outcomes are listed: Patient-Rated Wrist Evaluation, numerical rating for pain, and numerical rating for satisfaction. With multiple outcome measures and repeated assessments, interpretation depends on which outcomes and time points were planned as primary, and whether any adjustments or hierarchy were specified. The registry record does not report a multiplicity strategy or results for the secondary outcomes. No statistical findings across these measures can therefore be compared or interpreted from the record.

Missing-data details are also not reported in the registry record. There is no account of participants with missing DASH values at each assessment, reasons for missingness, or methods used to handle incomplete follow-up. The number assigned to each analysis population and the use of imputation or other missing-data methods are not reported. The record also does not specify whether analyses followed randomized assignment or were restricted to a subset. These omissions limit assessment of how representative the analyzed participants may have been and how missing outcomes could affect an estimate.

11. Safety Results

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

Other (non-serious) adverse events

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

The registry reports zero serious adverse events among 17 people at risk in the control group and zero among 20 people at risk in the computer-assisted planning group. It also reports zero other adverse events among 17 people at risk in the control group and zero among 20 people at risk in the computer-assisted planning group. These are the posted counts for the groups and event categories.

A count of zero means that no event in that category was recorded among the stated at-risk group in the registry results. It does not show that the underlying risk is exactly zero, and it cannot establish that the two approaches have equal safety. With finite groups, uncommon events may not be observed. The registry record does not provide event definitions, event-specific descriptions, timing, severity details beyond the serious/non-serious categories, or an analysis comparing groups. It also does not report the duration or completeness of adverse-event surveillance.

Death counts are not reported in the registry record; the absence of a numeric death count should not be interpreted as a reported zero. These safety figures are separate from the functional endpoint and cannot answer whether DASH differed between groups. They should be read as limited descriptive counts, not as a comprehensive safety evaluation or a causal estimate.

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

The registry record establishes that a randomized, multicenter trial was designed to compare computer-assisted with conventional preoperative planning for corrective osteotomy in extra-articular distal radius malunion. It also identifies DASH as the primary outcome, defines the direction of its scale, and lists several assessment times. These details explain the intended clinical and statistical question.

The record does not report the primary outcome values or a between-group analysis. It therefore does not show whether the groups had similar or different DASH scores, how large any difference was, or how precise an estimate might be. It also does not report a result at one selected follow-up time or a summary of change across time. The registry hypothesis is a statement of what investigators expected to test, not a result.

The enrollment listed is 40, but enrollment alone does not indicate the number of participants with complete outcome data or the number included in an analysis. The absence of reported analysis details also means that the role of missing data, baseline adjustment, and the handling of repeated observations cannot be assessed. These factors matter for interpreting an estimate if one is available; they cannot be resolved from the design description.

The reported adverse-event counts are descriptive and limited to the recorded categories and at-risk groups. Zero recorded events in those groups is not proof that no risk exists, and it is not a test of whether risks differ. Death counts are not reported in the registry record. The safety counts do not answer the functional comparison.

Accordingly, the record supports describing the trial question, design, endpoint, and a small set of safety counts. It does not support a claim that one planning approach produced better or worse function, or that either approach is safer. A completed status indicates that the study is recorded as completed; it does not replace the missing outcome estimates. The statistical conclusion must remain limited to what the registry actually reports.

13. Why This Trial Matters Statistically

This trial is statistically interesting because it separates the effect of a planning method from the operation itself. Both groups were described as undergoing corrective surgery, while the randomized contrast concerned computer-assisted versus non-computer-assisted preoperative planning. That design targets a focused question about whether the planning approach is associated with differences in subsequent function.

The outcome schedule also illustrates a common challenge in clinical trials: a continuous patient-reported measure is collected repeatedly over follow-up. A clear interpretation depends on specifying whether the main comparison is at one time point, concerns change from baseline, or evaluates the pattern across time. When several time points and secondary outcomes are present, prespecification and multiplicity handling are important to distinguish the principal inference from additional comparisons. The registry record does not report those analysis details.

The trial also highlights why a study's design and a study's results are distinct. Randomization describes how a comparison was intended to be formed, and the endpoint description explains what was intended to be measured. Neither supplies an effect estimate or its uncertainty. The registry record identifies a completed randomized trial but does not report primary outcome analyses, so the clinical question cannot be answered statistically from the posted results.

Finally, the safety counts show the limits of sparse descriptive information. Zero events were recorded in the specified adverse-event categories for the stated at-risk groups, but without detailed event reporting or an uncertainty analysis, those counts cannot establish absence of risk or a difference in safety. This is a useful reminder that clinical interpretation requires both transparent outcome reporting and an analysis suited to the question.

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 main trial-specific limitation of the registry record is that it does not report the primary outcome results. Although DASH is defined and follow-up is listed at 0, 3, 6, and 12 months, there are no group means, standard deviations, effect estimates, confidence intervals, or p-values. The comparative effect and its precision are therefore unavailable.

The primary measure has multiple listed time points, but the record does not specify a single primary comparison or an analysis of the repeated measurements. The analysis plan, statistical model, baseline adjustment, and center handling are not reported in the registry record. The record also does not describe how the multiple secondary outcomes and time points were handled statistically.

Enrollment is listed as 40, but the registry record does not provide participant flow, group sizes for the primary outcome analysis, or the amount and pattern of missing data. It does not state the analysis population or how incomplete outcome data were handled. Thus, it is not possible to assess whether the reported safety denominators correspond to the primary analysis population or how attrition may have affected outcome comparisons.

The record lists masking as none but does not report whether outcome assessors were masked. It does not give detailed information about randomization procedures, allocation concealment, protocol deviations, or the conventional planning process. The computer-assisted workflow is described at a high level, without enough information to assess implementation or variation across centers.

The adverse-event reporting is also limited: the registry gives aggregate counts for serious and other events but no event descriptions or death counts. These omissions restrict safety interpretation. Overall, these limitations concern reporting available in the registry record; they do not establish that analyses or procedures were absent from the trial itself.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Computer Assisted Planing of Corrective Osteotomy for Distal Radius Malunion — NCT01193010.
• Registry record last updated 2019-06-21; status last verified 2019-03.
• Results first posted 2019-06-21.
• 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 registry record describes a completed, randomized, parallel-group, multicenter trial comparing computer-assisted and conventional preoperative planning for corrective osteotomy in symptomatic extra-articular distal radius malunion. It lists an enrollment of 40 and no masking. The primary endpoint is DASH, a continuous upper-extremity function score for which higher values indicate worse function, assessed at 0, 3, 6, and 12 months.

The primary outcome results and statistical analysis are not reported in the registry record. Three secondary outcomes are listed, but their results are not reported. The record reports zero serious and zero other adverse events in each arm's stated at-risk group; death counts are not reported. Consequently, the clinical comparison's effect and precision cannot be determined from the posted results.