The effects of graft size and insertion site location during anterior cruciate ligament reconstruction on intercondylar notch impingement.
BACKGROUND
Intercondylar notch impingement is detrimental to the anterior cruciate ligament (ACL). Notchplasty is a preventative remodeling procedure performed on the intercondylar notch during ACL reconstruction (ACLR). This study investigates how ACL graft geometry and both tibial and femoral insertion site location may affect ACL-intercondylar notch interactions post ACLR. A range of ACL graft sizes are reported during ACLR, from six millimeters to 11mm in diameter. Variability of three millimeters in ACL insertion site location is reported during ACLR. This study aims to determine the post-operative effects of minor variations in graft size and insertion location on intercondylar notch impingement.


METHODS
Several 3D finite element knee joint models were constructed using three ACL graft sizes and polar arrays of tibial and femoral insertion locations. Each model was subjected to flexion, tibial external rotation, and valgus motion. Impingement force and contact area between the ACL and intercondylar notch compared well with experimental cadaver data from literature.


RESULTS
A three millimeter anterior-lateral tibial insertion site shift of the maximum size ACL increased impingement force by 242.9%. A three millimeter anterior-proximal femoral insertion site shift of the maximum size ACL increased impingement by 346.2%. Simulated notchplasty of five millimeters eliminated all impingement for the simulation with the greatest impingement. For the kinematics applied, small differences in graft size and insertion site location led to large increases in impingement force and contact area.


CONCLUSIONS
Minor surgical variations may increase ACL impingement. The results indicate that notchplasty reduces impingement during ACLR. Notchplasty may help to improve ACLR success rates.
Biomechanics Research Group, Northeastern University, 360 Huntington Avenue, Boston, MA, United States.
Alexander D
AD
Orsi
Department of Rehabilitation, UMass Memorial Hospital, Worcester, MA, United States.
Paul K
PK
Canavan
Biomechanics Research Group, Northeastern University, 360 Huntington Avenue, Boston, MA, United States.
Askhan
A
Vaziri
Sports Science Program, Qatar University, Doha, Qatar.
Ruben
R
Goebel
Department of Orthopaedic Surgery, Brigham and Women's Faulkner Hospital, Boston, MA, United States.
Onaly A
OA
Kapasi
Biomechanics Research Group, Northeastern University, 360 Huntington Avenue, Boston, MA, United States. Electronic address: hamid@coe.neu.edu.
Hamid
H
Nayeb-Hashemi
D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects / Q000379:methods*; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D005269:Femur / Q000601:surgery*; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D013314:Stress, Mechanical; D013977:Tibia / Q000601:surgery*
Anterior cruciate ligament; Graft size; Impingement; Insertion site; Notchplasty