Full-length standing radiographs can be used for determination of the Femoral neck-shaft angle but not acetabular coverage

Sufian S Ahmad; Christian Konrads; Annika Steinmeier; Max Ettinger; Henning Windhagen; Gregor M Giebel

doi:10.1051/sicotj/2022033

Full-length standing radiographs can be used for determination of the Femoral neck-shaft angle but not acetabular coverage

SICOT J. 2022:8:34. doi: 10.1051/sicotj/2022033. Epub 2022 Aug 24.

Authors

Sufian S Ahmad¹, Christian Konrads², Annika Steinmeier³, Max Ettinger⁴, Henning Windhagen⁴, Gregor M Giebel³

Affiliations

¹ Department of Orthopaedic Surgery, Hannover Medical School, 30625 Hannover, Germany - Faculty of Medicine, University of Tübingen, 72076 Tübingen, Germany.
² Department of Orthopaedic Surgery, University of Tübingen, 72076 Tübingen, Germany.
³ Center for Musculoskeletal Surgery, Charité - University Medical Center, 10117 Berlin, Germany.
⁴ Department of Orthopaedic Surgery, Hannover Medical School, 30625 Hannover, Germany.

Abstract

Introduction: The exact evaluation of hip morphology is essential for surgical planning. A wide range of morphometric measures of the acetabulum is deduced from conventional anterior-posterior (ap) pelvic radiographs. Full-length weight-bearing radiographs (FLWBR) also depict the acetabulum and are commonly used for osteotomy planning of the lower limb. This study aimed to determine whether FLWBR can be used to evaluate acetabular morphology.

Methods: Radiographs of patients receiving a hip workup that included a conventional ap pelvic X-ray and FLWBR were utilized for radiographic measurements. The following parameters were measured: extrusion index of the femoral head, anterior wall index, posterior wall index, lateral center edge angle (LCE), acetabular index, pubic arc angle (subpubic angle), and centrum-collum-diaphyseal angle (CCD).

Results: FLWBR depicted a significantly reduced anterior coverage (p = 0.049) and increased posterior coverage (p < 0.001), higher acetabular index (p = 0.015), and higher pubic-arc angle (p = 0.02) compared to conventional ap pelvic radiographs. There were no significant differences regarding the CCD angle (p = 0.28), extrusion index (p = 0.31), and LCE (p = 0.16).

Discussion: The CCD angle of the femur can be measured on conventional ap radiographs and full-length weight-bearing X-rays for lower limb deformity analysis. However, FLWBR will depict an anteverted acetabular morphology, rendering conventional ap radiographs necessary for planning pelvic osteotomies.

Keywords: Conventional ap pelvic radiograph; Distal femur osteotomy; Femoroacetabular impingement; Full-length weight-bearing X-ray; High tibial osteotomy; Hip dysplasia; Osteotomy.