Limb Lengthening and Reconstruction Society AIM index reliably assesses lower limb deformity.
BACKGROUND
Although several systems exist for classifying specific limb deformities, there currently are no validated rating scales for evaluating the complexity of general lower limb deformities. Accurate assessment of the complexity of a limb deformity is essential for successful treatment. A committee of the Limb Lengthening and Reconstruction Society (LLRS) therefore developed the LLRS AIM Index to quantify the severity of a broad range of lower extremity deformities in seven domains.


OBJECTIVE
We addressed two questions: (1) Does the LLRS AIM Index show construct validity by correlating with rankings of case complexity? (2) Does the LLRS AIM Index show sufficient interrater and intrarater reliabilities?


METHODS
We had eight surgeons evaluate 10 fictionalized patients with various lower limb deformities. First, they ranked the cases from simplest to most complex, and then they rated the cases using the LLRS AIM Index. Two or more weeks later, they rated the cases again. We assessed reliability using the Kendall's W test.


RESULTS
Raters were consistent in their rankings of case complexity (W = 0.33). Patient rankings also correlated with both sets of LLRS AIM ratings (r(2) = 0.25; r(2) = 0.23). The LLRS AIM Index showed interrater reliability with an intraclass correlation (ICC) of 0.97 for Trial 1 and 0.98 for Trial 2 and intrarater reliability with an ICC of 0.94. The LLRS AIM Index ratings also were highly consistent between the attending surgeons and surgeons-in-training (ICC = 0.91).


CONCLUSIONS
Our preliminarily observations suggest that the LLRS AIM Index reliably classifies the complexity of lower limb deformities in and between observers.
Division of Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, ML 2017, Cincinnati, OH 45229, USA. james.mccarthy@cchmc.org
James J
JJ
McCarthy
Christopher A
CA
Iobst
S Robert
SR
Rozbruch
Sanjeev
S
Sabharwal
Emily A
EA
Eismann
D006801:Humans; D038061:Lower Extremity Deformities, Congenital / Q000145:classification*; D015203:Reproducibility of Results; D012720:Severity of Illness Index