Update on the state of outcome measurement in total elbow arthroplasty research: identifying a need for consensus

There is little consensus for a standard set of metrics to express outcome after total elbow arthroplasty. In order to set the stage for future work toward a core set of measurement tools, our goal was to gather a complete view of the outcomes used in total elbow arthroplasty research, the concepts of their focus, and their quality as measures of the target concept.

We reviewed the outcome measures for total elbow arthroplasty presented in the literature from 2004 to 2011 in terms of the instruments used and their concepts of focus. We reviewed the reliability, validity, and responsiveness of the prevailing measurement tools.

Of the seventy-two articles identified, 90% (sixty-five) used elbow-specific aggregate outcome measures, which combine concepts, such as physiological variables, with symptom status and functional status. The Mayo Elbow Performance Score, or a variation of that scoring system, was used in fifty-four (75%) of the seventy-two articles. Most outcomes pertained to biological and physiological variables, with fewer outcomes focusing on symptoms, function, or overall health status. A review of the measurement properties of the elbow-specific aggregate outcome measures did not reveal one to be superior.

Overall, total elbow arthroplasty outcomes are heterogeneous in their reporting and lack standardization. The total elbow arthroplasty literature relies on several physician-derived elbow-specific aggregate measures and focuses primarily on physiological variables. The relative merits of aggregating findings into a single scoring system versus as separate components should be explored further. Finally, consideration should be given to patient-reported outcome measures in total elbow arthroplasty research.

This study of the current "state of practice" for outcome measurement in total elbow arthroplasty revealed gaps in the breadth of measurement and a lack of comparability in elbow scoring systems that could hinder our ability to clearly and fully understand outcome after total elbow arthroplasty. Future consensus work could address both concerns and assist in the development of a core set of outcome measures.