Background: Anterior cruciate ligament reconstruction employing transtibial tunnel techniques may result in less than ideal femoral and tibial vertical graft placement, with a residual pivot shift and instability symptoms.
Hypothesis: Nonanatomical graft placement is highly prevalent among knees with failed primary and revision anterior cruciate ligament grafts.
Study design: Case series; Level of evidence, 4.
Methods: A total of 122 consecutive patients presented to the authors' center with a failed anterior cruciate ligament reconstruction. Radiographs, magnetic resonance imaging, and operative reports were used to define graft placement. Arthroscopic confirmation of graft placement was obtained in 92 knees during subsequent revision surgery. A nonanatomical graft placement was assigned when ≥50% of the graft was outside of the native tibial and femoral insertions. All patients prospectively completed Cincinnati Knee Rating System questionnaires.
Results: A nonanatomical graft placement occurred in 107 of 122 (88%) knees; 61% of the grafts were entirely on the intercondylar femoral roof, and 35% extended posterior to the anterior cruciate ligament tibial attachment. A transtibial technique had been used in 83%. The mean values for the coronal and sagittal graft placement showed a significantly increased vertical orientation in comparison with a control group (P < .01). Forty-two of the 107 nonanatomical grafts had undergone 1 or more revisions without correction of the misplaced graft tunnels, and these subsequently failed.
Conclusion: The occurrence of nonanatomical graft placement in primary and revision knees may represent an inadequacy of transtibial tunnel drilling techniques to obtain graft placement within the native femoral and tibial footprints. In revision cases, the prior graft location requires close scrutiny so the new graft tunnels are placed at the native anterior cruciate ligament attachments. Independent drilling of tibial and femoral tunnels is recommended using either 2-incision or anteromedial portal techniques.