Assessment of the Gordon lateral rotation index in postoperative rotational evaluation of supracondylar humerus fractures: a study on validity, reliability, and applicability

There are several methods for the assessment and follow-up of reduction of supracondylar humerus fractures, which offer the possibility of evaluation in different planes. The Gordon lateral rotation index (GLRI) is one of the methods used to assess the axial plane. This study aims to evaluate the validity, reliability, and applicability of the GLRI to assess rotational alignment. The study included 50 patients with Gartland type 3 supracondylar humerus fracture. After closed reduction, fixation with 2 lateral pins and 1 medial pin was applied to all patients. Eight observers made measurements using follow-up radiographs in the early postoperative period and at the 3^rd week. Gordon lateral rotation percentage (GLRP) significantly decreased from baseline to week 3 in all participants (P < 0.01). When the intraclass correlation coefficient (ICC) between the GLRP measurements of the observers in the early postoperative period was examined, a moderate agreement of 0.453 was seen between measurements of the observers (ICC = 0.453; P = 0.001; P < 0.01). When the ICC between the 3^rd week GLRP measurements of the observers was analyzed, poor agreement of 0.294 was seen (ICC = 0.294; P = 0.001; P < 0.01). The GLRI has moderate validity, applicability, and reliability in the early postoperative period, and low validity, applicability, and reliability in the follow-up period. Consequently, GLRI is an objective method that can be used to assess rotational alignment in the early postoperative period of supracondylar humerus fractures. It is, however, not recommended for follow-up periods.