ACL Reconstruction Double Bundle VS Single Bundle Reconstruction

Incidence ACL Injury • Over 100, 000 ACL tears occur each year in the United States.

ACL Anatomy: AM and PL Bundles

Anatomy: AM and PL Bundles

Anterior Medial Bundle • Controls anterior translation of tibia. • Relatively taut throughout knee motion, maximum between 45 -60 degrees.

Posterolateral Bundle • Controls Rotatory stability of knee. • Taut in extension, between 0 -15 degrees.

MRI Images: AM & PL

Arthroscopic View: AM & PL

Why Do Double Bundle? *Between 10% and 30% of patients complain of pain and residual instability following Single-Bundle ACL reconstruction. *Arthritis has been observed on xrays in up to 90% of patients at long -term follow-up after Single-Bundle ACL reconstruction.

Why do Double Bundle? • Single-Bundle ACL reconstruction does not adequately restore normal knee stability, particularly tibial rotation. • Double-Bundle reconstruction better restores knee stability.

Fu: Evolution of the Door

Incisions for Double Bundle Three arthroscopic incisions AL—Anterolateral Portal AM—Anteromedial Portal AC—Accessory Portal

Tunnels for Double Bundle

Graft Placement: Double Bundle

MRI of Double Bundle Reconstruction

MRI: AM Bundle Reconstructed

MRI: PL Bundle Reconstructed

Outcome of Single-bundle Versus Double-bundle Reconstruction of the Anterior Cruciate Ligament A Meta-analysis Richard B. Meredick, MD*, Kennan J. Vance, DO*, David Appleby, MPH and James H. Lubowitz, MD*, The American Journal of Sports Medicine 36: 14141421 (2008)

Outcome of Single-bundle Versus Double-bundle Reconstruction of the Anterior Cruciate Ligament A Meta-analysis Conclusion: Double-bundle reconstruction does not result in clinically significant differences in KT-1000 arthrometer or pivotshift testing.

Why Not to Do Double Bundle ACL Reconstruction? • A few studies have shown an increased incidence of pivot shift after double bundle reconstruction. (Columbet et al 2006; Munet et al 2006) • More vertical placement of the AM femoral tunnel and medial placement of the AM tibial tunnel may lead to PCL impingement and instability with pivot shift. (Howell, Roundtable Discussion, Ortho Today, 2008)

Howell: Move Femoral Tunnel Laterally to Avoid PCL Impingement (Single Bundle)

Summary • Double Bundle Reconstruction appears to have some promising results for the right indications and done with proper technique. • There is still debate and no real conclusion on whether either technique is better. • Refining technique with single bundle reconstruction may improve results as well without the increased risk of a more technically challenging procedure.