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Chapter 118Current ‘anatomic’ ACL reconstruction: where does it go wrong?The aim of an anatomic ACL reconstruction is for a graft to be implanted on the native footprints of the ACL on the femur and tibia. Current surgical techniques seem to fall short in creating a constant and reliable result for a femoral tunnel position at the optimal, individual anatomic footprint of the ACL. Surgeons using an ‘anatomic’ ACL reconstruction technique have been shown to deviate 4-5 mm from their intended femoral tunnel position.24 This may be the result of poor visibility of the footprint during surgery as it is hidden in the intercondylar notch. Besides, large variability has been shown in the exact anatomic location of the footprints of the ACL between patients.23Although femoral and tibial bone tunnels are drilled through surgical guide instruments to optimise positioning, current surgical techniques still depend on the intraoperative identification of landmarks and measurements to determine the femoral footprint of the ACL. The use of anatomical landmarks to ensure anatomic positioning of the graft is associated with a high risk of femoral tunnel malpositioning, which is related to early-tomidterm failure of the graft.13,15 Non-anatomical placement of the ACL graft can lead to residual rotational laxity and is associated with a higher rate of graft failure, i.e. elongation or re-rupture. It is demonstrated that surgical inaccuracy, and in particular inaccuracy in femoral tunnel positioning, is an important factor causing ACL graft failure.13 This can be devastating for the patient, leading to additional injury to knee structures such as menisci, requiring additional surgery, and causing prolonged absence from or even cessation of sports activities. To provide consistent results, determination of the native ACL footprint should not be dependent of surgeon’s experience or intraoperative visual control, and individual variation should be taken into account. A way to solve this is to identify the femoral footprint before surgery and to create a patient-specific instrument to ensure a femoral tunnel emerging at the native ACL position. This may improve biomechanical outcome after ACL reconstruction. Mark Zee.indd 18 03-01-2024 08:56