Summary

Combined Anterior Cruciate Ligament Reconstruction and Modified Lemaire Lateral Extra-Articular Tenodesis better restores Knee Stability and reduces Failure Rates than Isolated Anterior Cruciate Ligament reconstruction in Skeletally Immature Patients

Abstract

The increase in anterior cruciate ligament (ACL) injuries in pediatric patients and the high failure rate reported in the literature in this population are driving surgeons to search for specific techniques to better restore knee stability. Recent literature has reported that the combination of lateral extra-articular tenodesis (LET) and ACL reconstruction improves outcomes in high-risk patients. However, such advantages in pediatric patients have been infrequently evaluated. The aim of this study is to assess whether adding LET to ACL reconstruction can significantly improve knee stability, clinical outcomes, and failure rates in pediatric patients.
A multicentric study was conducted to evaluate pediatric patients who have undergone primary ACL reconstruction using a physeal sparing femoral drilling technique. A minimum 2-year follow-up evaluation was required. The patients were divided into 2 group: patients in group 1 underwent an isolated ACL reconstruction and patients included in group 2 had an ACL reconstruction in combination with a modified Lemaire LET procedure. Group 1 was a historical control cohort of patients, whereas group 2 was prospectively enrolled. All the patients were clinically evaluated using the Pedi-IKDC and the Pedi-FABS score. Anteroposterior knee stability was measured using the KT-1000 and the objective pivot shift evaluation was documented with a triaxial accelerometer. The included patients also underwent a standardized radiological protocol to evaluate leg-length-discrepancies, axial deviation and degenerative signs preoperatively and at last follow-up. A post-hoc calculation achieved a power of 82.6% for the KT-1000, 88.3% for the KiRA evaluation and 85.1% relative to the subjective IKDC at the two-year follow-up.
This study included 66 pediatric patients with an anatomic ACL reconstruction using an autologous four-strand hamstring graft. In group 1 there were 34 patients (mean bone age 13.5 ± 1.2 years), while 32 patients (mean bone age 13.8 ± 1.4 years) were included in group 2. The clinical outcome scores showed no difference between the two groups (Pedi-IKDC, p= .072; Pedi-FABS, p= .180). The patients in group 2 had better anteroposterior stability measured with a KT-1000 (1.9 ± 1.1 group 1 VS 0.8 ± 0.8 group 2; p= .031), as well as better rotational stability measured with KIRA (–0.59 ± 1.05 group 1 VS 0.98 ± 1.12 group 2; p= .012). The patients of the two groups returned to sport at the same competitive level without significant differences (82,4% group 1 VS 90.6% group 2; p= .059).
No leg-length-discrepancies were found between the 2 groups at last follow-up (p= .881). Three patients displayed an increased valgus deformity of 3º on the operated limb at last follow-up (two in group 1 and one in group 2). Group 1 had a significatively higher cumulative failure rate (14.7% vs 6.3%; p = .021).

Conclusions

performing a modified Lemaire LET along with an ACL reconstruction with hamstrings in pediatric patients reduces the cumulative failure rate and improves objective stability with no increase in intra- or postoperative complications. No significant difference was found between the two groups in terms of patient-reported outcomes or in the return to sport activity.