Operability score: An innovative tool for quantitative assessment of operability in comparative studies on surgical anatomy

Objectives Comparative anatomical studies have proved to be invaluable in the evaluation of advantages and drawbacks of single approaches to access established target areas. Approach-related exposed areas do not necessarily represent useful areas when performing surgical manoeuvres. Accordingly the concept of "operability" has recently been introduced as a qualitative assessment of the ability to execute surgical manoeuvres. The authors propose an innovative model for the quantitative assessment of the operability, defined as "operability score" (OS), which can be effectively and easily applied to comparative studies on surgical anatomy. Methods A microanatomical study was conducted on six cadaveric heads. Results Morphometric measurements were collected and operability scores in selected target points of the surgical field were calculated. As illustrative example, the operability score was applied to the extradural subtemporal transzygomatic approach (ESTZ). Conclusion The operability score is effective in grading system of surgical operability, and instruments manipulation capability. It is a useful tool to evaluate, in a single approach, areas that can be exposed, and to quantify how those areas are suitable for surgical manoeuvres.