Arthroscopic agreement among surgeons on anterior cruciate ligament tunnel placement

Abstract

Background: Little is known about surgeon agreement and accuracy using arthroscopic evaluation of anterior cruciate ligament (ACL) tunnel positioning.

Purpose: To investigate agreement on ACL tunnel position evaluated arthroscopically between operating surgeons and reviewing surgeons. We hypothesized that operating and evaluating surgeons would characterize tunnel positions significantly differently.

Study design: Controlled laboratory study.

Methods: Twelve surgeons drilled ACL tunnels on 72 cadaveric knees using transtibial (TT), medial portal (MP), or 2-incision (TI) techniques and then completed a detailed assessment form on tunnel positioning. Then, 3 independent blinded surgeon reviewers each arthroscopically evaluated tunnel position and completed the assessment form. Statistical comparisons of tunnel position evaluation between operating and reviewing surgeons were completed. Three-dimensional (3D) computed tomography (CT) scans were performed and compared with arthroscopic assessments. Arthroscopic assessments were compared with CT tunnel location criteria.

Results: Operating surgeons were significantly more likely to evaluate femoral tunnel position (92.6% vs 69.2%; P = .0054) and femoral back wall thickness as "ideal" compared with reviewing surgeons. Tunnels were judged ideal by reviewing surgeons more often when the TI technique was used compared with the MP and TT techniques. Operating surgeons were more likely to evaluate tibial tunnel position as ideal (95.5% vs 57.1%; P < .0001) and "acceptable" compared with reviewers. The ACL tunnels drilled using the TT technique were least likely to be judged as ideal on the tibia and the femur. Agreement among surgeons and observers was poor for all parameters (κ = -0.0053 to 0.2457). By 3D CT criteria, 88% of femoral tunnels and 78% of tibial tunnels were placed within applied criteria.

Conclusion: Operating surgeons are more likely to judge their tunnels favorably than observers. However, independent surgeon reviewers appear to be more critical than results of 3D CT imaging measures. When subjectively evaluated arthroscopically, the TT technique yields more subjectively poorly positioned tunnels than the TI and MP techniques. Surgeons do not agree on the ideal placement for single-bundle ACL tunnels.

Clinical relevance: This study demonstrates that surgeons do not currently uniformly agree on ideal single-bundle tunnel placement and that the TT technique may yield more poorly placed tunnels.