All-epiphyseal Anterior Cruciate Ligament Reconstruction Research Articles

All-Epiphyseal Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: A Surgical Technique Using a Split Tibial Tunnel

Many techniques have been described for anterior cruciate ligament (ACL) reconstruction in skeletally immature patients, including extra-articular, complete or partial transphyseal, and physeal-sparing techniques. An all-epiphyseal technique places the tendon and its tunnels and fixation all within the child's epiphysis, leaving the growth plates untouched. We describe an all-epiphyseal quadruple-hamstring ACL reconstruction using a split tibial tunnel. The split tibial tunnels drop the tunnel size down to 4.5 to 5.5 mm from 7 to 8 mm because only half the total graft diameter passes through each of the split tunnels. This increases the safety margin for keeping the tunnel within the tibial epiphysis, in addition to avoiding damage into the growth plate. The bone bridge between the 2 tunnels serves as a solid low-profile fixation post. Femoral graft fixation is achieved with an interference screw, which allows precise tensioning and low-profile fixation entirely within the femoral tunnel. By placing the graft at the native ACL's anatomic attachment points without spanning or violating the growth plates at any step of the procedure, an all-epiphyseal ACL reconstruction with a split tibial tunnel theoretically minimizes the risk of growth disturbance in an ACL-deficient child.

All-epiphyseal ACL Reconstruction Improves Tibiofemoral Contact

Anterior cruciate ligament (ACL) injury alters tibiofemoral contact during function, with a posterior shift of the point of contact on the tibia. An all-epiphyseal approach to ACL reconstruction is performed in pediatric patients to improve tibiofemoral contact without disturbing the physis. The hypothesis of the study is that all-epiphyseal ACL reconstruction will shift contact anteriorly on the tibia, as compared with the ACL-deficient knee. Ten cadaver knees were tested with the ACL cut and with an all-epiphyseal reconstruction. The knees were set at multiple flexion angles (0, 15, 30, and 45 degrees) and loaded with a quadriceps force of 596 N in combination with an anterior force of 100 N, with the quadriceps loaded in isolation, and with the quadriceps loaded in combination with a hamstrings force of 200 N. Sensors under the menisci characterized the center of force on the tibia. Paired t tests were used to identify significant (P<0.05) differences between the reconstructed and cut conditions for all loading conditions at all flexion angles. On the medial plateau, the average center of force was 2 to 5 mm more anterior for the reconstructed condition than for the ACL cut, with the difference significant for all test conditions. The largest differences between the ACL conditions occurred for the combination of quadriceps forces plus an anterior force. On the lateral plateau, the anterior shift in the center of force from the ACL cut to reconstructed condition was significant for all flexion angles except 0 degree for all loading conditions, with an average difference of approximately 2 mm for all significant differences. All-epiphyseal ACL reconstruction shifts contact anteriorly on the tibia compared with the injured knee. The anterior shift of contact on the femur related to all-epiphyseal ACL reconstruction reduces changes related to ACL injury, which could reduce the risk of cartilage damage and meniscal injuries without violating the growth plate in pediatric patients.

All-epiphyseal Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients

Treating ACL injuries in prepubescent patients requires balancing the risk of chondral and meniscal injuries associated with delaying treatment against the risk of growth disturbance from early surgical reconstruction. Multiple physeal respecting techniques have been described to address this vulnerable population; however, none restore the native ACL attachments while keeping the graft and fixation entirely in the epiphysis. We describe a technique of all-epiphyseal ACL reconstruction for use in prepubescent skeletally immature patients. Intraoperative CT scanning with three-dimensional (3-D) reconstruction was used to confirm the precise localization of the all-epiphyseal femoral and tibial tunnels. The femoral tunnel is drilled entirely in the epiphysis of the lateral femoral condyle. The tibial tunnel is drilled from inside-out to the level of the tibial physis using a retrograde drill. Fixation of the soft tissue graft is achieved with a retrograde interference screw in the tibia and an interference screw in the femur. Case examples are presented for three boys aged 10-12, Tanner Stage 1 development, with a minimum followup of 1 year. All three patients had stable knees based on Lachman and KT-1000 testing and no evidence of growth disturbance. All had full ROM and symmetric strength for knee flexion and extension. All patients returned to their sports activities using a custom ACL brace. Although longer-term followup will be necessary, this technique provides for an anatomic all-epiphyseal-based ACL reconstruction using intraoperative 3-D imaging to minimize the risk of growth disturbance. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.