Training and evaluating spinal surgeons: the development of novel performance measures.

STUDY DESIGN

Cohort study.

OBJECTIVE

The purpose of this study was to develop and validate a series of novel assessment measures for use during a lumbar pedicle cannulation task.

SUMMARY OF BACKGROUND DATA

There is increasing pressure being placed on the surgical community to develop appropriate assessment measures of technical skills as an indicator of surgical competence. To date, little research has been performed in this area in spinal surgery.

METHODS

Twelve novice and 7 expert spine surgeons cannulated a complete set of lumbar pedicles on a synthetic model. Electromagnetic markers were traced to record their dominant hand and arm movements while the forces applied to the model were measured using a small force plate. The amount of wrist motion, mean forces, peak forces, and task time were evaluated. Following task completion, angles of pedicle cannulation and the number and location of all breaches in the models were recorded.

RESULTS

Novice surgeons used less mean force (91 N vs. 115 N, P = 0.001) but required more time to perform each cannulation task (12.4 seconds vs. 8.2 seconds, P < 0.001). Cannulation by novices demonstrated a greater mean number of frank (far lateral) pedicle breaches (1.5 vs. 0 per individual, P = 0.002), but no differences in the angles of cannulation were seen (P = 0.988).

CONCLUSION

Four variables, 3 involving process measures and 1 an outcome measure, can be used to distinguish between novice and expert spine surgeons using a simple lumbar spine pedicle cannulation task, providing evidence of their construct validity. Knowledge of these differences may be useful in objective evaluation of surgical competence and providing precise feedback during the training of this skill, thereby enhancing learning.