Time to Get Rid of the Clock: Intraobserver and Interobserver Reliability in Determination of the O'clock Position of the Femoral Tunnel in ACL Reconstruction

Abstract

This study evaluates intraobserver and interobserver agreement in reporting the o'clock position of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction. Four PGY2 residents, four PGY5 residents, and four sports medicine orthopedic surgeons reported the o'clock position of the femoral ACL tunnel in 10 arthroscopic pictures on two occasions 3 months apart. Intraobserver agreement was determined using the intraobserver correlation coefficient (r > 0.576 for 0.05 significance level). Interobserver agreement between members of each group and between reviewer groups was evaluated with the intraclass correlation coefficient (ICC > 0.75 considered good agreement). Poor interobserver agreement was demonstrated between the attending and PGY2 groups (ICC = 0.1685), between the attending and PGY5 groups (ICC = 0.2982), and between the PGY5 and PGY2 groups (ICC = 0.267). Attending surgeons, PGY5s, and PGY2s demonstrated poor interobserver agreement amongst themselves (ICC = 0.2244, 0.471, and 0.0859, respectively). PGY2s and PGY5s demonstrated good intraobserver agreement, but attending surgeons demonstrated poor intraobserver agreement. Attending orthopedic surgeons and residents of different levels of training interpret the o'clock position of the femoral tunnel differently. Greater years of experience does not improve intraobserver or interobserver agreement on the o'clock position. The clock face terminology for femoral tunnel placement may not be a reliable descriptor for scientific investigations or clinical instruction.