Radiographic acetabulotrochanteric distance measurement as a novel method for determining leg length discrepancy in patients with hemiarthroplasty

Ugur Yuzuguldu; Bilge Kagan Yilmaz; Ibrahim Ethem Butuner; Murat Yesil; Gokhan Maralcan

doi:10.52312/jdrs.2025.2285

Ugur Yuzuguldu¹, Bilge Kagan Yilmaz², Ibrahim Ethem Butuner³, Murat Yesil², Gokhan Maralcan⁴

¹Department of Orthopedics and Traumatology, Atatürk City Hospital, Balıkesir, Türkiye
²Department of Orthopedics and Traumatology, Afyonkarahisar Health Sciences University, Afyonkarahisar, Türkiye
³Department of Orthopedics and Traumatology, Edremit State Hospital, Balıkesir, Türkiye
⁴Department of Orthopedics and Traumatology, Okan University Hospital, İstanbul, Türkiye

Keywords: Acetabulotrochanteric distance, hemiarthroplasty, hip joint, leg length discrepancy, pelvic radiography.

Abstract

Objectives: This study aims to evaluate the interobserver reliability and interobserver reproducibility of radiographic acetabulotrochanteric distance (ATD) measurement and to investigate its accuracy by comparing it with conventional radiographic methods used in leg length discrepancy (LLD) measurement.

Patients and methods: Between January 2017 and January 2022, a total of 97 patients (39 males, 58 females; mean age: 77.8±7.1 years; range, 61 to 91 years) who underwent pelvic radiographic evaluation and hemiarthroplasty (HA) due to femoral neck fracture were retrospectively analyzed. For ATD measurement, the distance between the line connecting the upper cartilage of the acetabulum (AC) and the extreme point of the greater trochanter (GT) was used. The AC-GT measurement on both sides was compared with bottom of the ischial tuberosities-lesser trochanter (BI-LT), center of the femoral head-BI (CH-BI), inferior acetabular teardrops-LT (IT-LT) measurements. The agreement between the methods was examined with the intraclass correlation coefficient (CCI).

Results: According to the AC-GT & BI-LT, AC-GT & BI-CH methods, there were very strong (ICC: 0.75), moderate (ICC: 0.69) and acceptable (ICC: 0.33) agreements, respectively. Significant agreement was found between all measurements (p<0.001). A positive correlation was detected in the correlation analysis of all measurements (p<0.001). Intra- and interobserver agreement for ATD measurement (AC-GT) was excellent (ICC: >0.8).

Conclusion: The ATD measurement correlates well with known measurement techniques on pelvic radiography and can be used as an alternative to this method. It has excellent intra- and interobserver agreements. This method can predict LLD after HA, but does not consider other length differences in the lower limbs.

Citation: Yuzuguldu U, Yilmaz BK, Butuner IE, Yesil M, Maralcan G. Radiographic acetabulotrochanteric distance measurement as a novel method for determining leg length discrepancy in patients with hemiarthroplasty. Jt Dis Relat Surg 2025;36(3):675-682. doi: 10.52312/jdrs.2025.2285.