Validation of novel and objective measures of microsurgical skill: Hand-motion analysis and stereoscopic visual acuity

Our purposes were: 1) to establish the predictive validity of stereoscopic visual acuity and microsurgical performance, and 2) to establish the construct and concurrent validity of hand-motion analysis as an objective and sensitive measure of microsurgical performance. Using a surgical microscope, 50 surgical residents completed a standardized microsurgical suturing task at baseline and following microsurgical training. Microsurgical performance was evaluated by blinded, expert microsurgeons using global rating scales. Measures of stereoscopic visual acuity and hand-motion analysis were correlated with expert global rating scores. Global rating scores correlated significantly with number of hand movements (r = -0.47, P = 0.001) and hand-travel distance (r = -0.37, P = 0.008). Economy of hand-motion improved significantly following microsurgical training (number of hand movements, P = 0.046; hand-travel distance, P = 0.04). Measures of stereoscopic visual acuity did not correlate significantly with global rating scores. Hand-motion analysis appears to be an objective and sensitive instrument for assessing microsurgical performance, with evidence of both concurrent and construct validity. The predictive validity of stereoscopic visual acuity and microsurgical performance remains unclear.