Transphyseal anterior cruciate ligament reconstruction in skeletally immature patients: Quantification of physeal damage using a three-dimensional simulation model study.

PURPOSE: This study investigated how tunnel orientation and diameter affect physeal damage during transphyseal anatomic anterior cruciate ligament (ACL) reconstruction. The focus was on the distal femoral physis (DFP) and proximal tibial physis (PTP) using a three-dimensional (3D) model derived from magnetic resonance imaging (MRI) of skeletally immature patients.

METHODS

MRI scans from patients aged 10-17 years were segmented to create 3D models of the distal femur, proximal tibia, and their respective physes. Simulations of full-length ACL tunnels were performed using 7-, 8-, 9-, and 10-mm drills, starting at the ACL footprint and covering all possible angulations. Physeal damage was quantified as a percentage of total growth plate volume and analyzed according to tunnel diameter, orientation, patient age, and sex. Statistical analyses were applied, with significance set at P < 0.05.

RESULTS

Maximum DFP damage (14.6 % ± 3.9) occurred with horizontal tunnels and 10-mm drill diameter, with significantly greater damage in males. Less than 7 % DFP damage was observed when using vertical tunnels (>45° cephalic) and anteromedial (AM) portal direction. For the PTP, the highest damage occurred with oblique angles and 10-mm drills (5.5 % ± 2.4), with statistically significant variation by tunnel size and patient age, but not by sex.

CONCLUSIONS

Tunnel orientation and diameter significantly influence physeal damage during pediatric ACL reconstruction. Vertical tunnels and anteromedial drilling directions minimize growth plate injury, supporting their use in surgical planning to reduce the risk of long-term growth disturbances.