Correlation of the LLRS-AIM Index With LD-SRS and PROMIS in Pediatric Patients With Lower Limb Differences.

Abstract

The purpose of this study was to assess the reliability of the Limb Lengthening and Reconstruction Society AIM (LLRS-AIM) index, a scale for grading the severity of lower limb deformities by the physician, and its concordance with 2 patient-reported outcome measures, the Limb Deformity-Scoliosis Research Society (LD-SRS) and Patient-Reported Outcomes Measurement Information System (PROMIS) tools in pediatric patients with lower limb differences. This was a retrospective review of patients 18 years old or younger who presented to our institution with lower limb differences for surgical reconstruction between 2019 and 2024. All patients received the LD-SRS and PROMIS for completion before surgery. The LLRS-AIM index for patients was assessed by 2 independent evaluators, with intraclass correlation coefficients (ICCs) calculated to determine inter-rater agreement. Spearman correlations were performed between the LLRS-AIM Index with all LD-SRS and PROMIS domains. The Benjamini-Hochberg procedure was conducted to reduce the false discovery rate. A total of 81 patients were included in this study. The LLRS-AIM Index had good and near-perfect inter-rater reliability across different levels of medical training (ICC=0.9). Overall, there were no correlations between the LLRS-AIM Index with LD-SRS and PROMIS domains (LD-SRS function: P=-0.26, P=0.18; PROMIS pain interference: P=0.10, P=0.63). Mental health-related LD-SRS and PROMIS domains showed no correlations with the physician-reported LLRS-AIM index (LD-SRS self image: P=0.10, P=0.63; PROMIS depression: P=-0.05, P=0.63). There is a high level of reproducibility for the LLRS-AIM index to evaluate the complexity of lower limb differences in pediatric patients. However, there are no correlations between the LLRS-AIM index with LD-SRS and PROMIS across all relevant domains. Further modifications to the LLRS-AIM index criteria and scoring weights may allow it to better assess patient outcomes in the pediatric population. Level III.