Comparative Analysis of Iliotibial Band Graft Length in Pediatric Anterior Cruciate Ligament Reconstruction: MacIntosh Versus All-Epiphyseal Femoral Drilling Technique

Abstract

Background:

Iliotibial band (ITB) grafts yield excellent outcomes for anterior cruciate ligament reconstruction (ACLR) in skeletally immature patients. Because closure of the ITB harvest interval is often not feasible, techniques that allow for shorter ITB grafts may be beneficial.

Hypothesis:

That the all-epiphyseal femur ITB graft would be significantly shorter than the over-the-top ITB graft.

Study Design:

Controlled laboratory study.

Methods:

Six fresh-frozen pediatric knees (mean age, 9.7 years; range, 9-11 years) were used. Surgeons simulated the modified MacIntosh and all-epiphyseal ITB ACLRs using No. 2 suture as a proxy for the ITB graft. A suture was attached at the ITB origin on the Gerdy tubercle and then passed over-the-top on the femur, under the transverse meniscal ligament, and to the metaphyseal anchor point. The length of the suture was measured. The suture was then placed through the all-epiphyseal femoral drill hole, under the transverse meniscal ligament to the same tibial metaphyseal anchor point. Femoral condyle width was recorded, and the relationship between graft length and technique was analyzed using analysis of covariance to adjust for femoral condyle widths.

Results:

Graft length for the all-epiphyseal ITB ACLR was significantly shorter than that for the modified MacIntosh ITB ACLR, with a mean difference of 26.0 ± 6.0 mm (P < .001). Across both groups, each additional millimeter of condyle width was associated with an increase in graft length by 2.3 mm (P < .001). Mean graft lengths for the modified MacIntosh and all-epiphyseal femur were 173.3 ± 16.5 mm and 147.3 ± 16.0 mm, respectively.

Conclusion:

The all-epiphyseal femoral technique requires a significantly shorter ITB graft length compared with the modified MacIntosh technique. A nomogram was developed to estimate graft length differences adjusted for condyle width. Future pediatric studies should continue to explore the biomechanics of both graft techniques, as they may provide lateral extra-articular stabilization and reduce ACL reinjury rates.

Clinical Relevance:

Shortened ITB autograft length may reduce symptoms associated with muscle herniation.