Femoral Neck Shaft Angle and Management of Proximal Femur Fractures: Is the Contralateral Femur a Reliable Template?. Issue 10 (October 2021)

• Record Type: Journal Article
• Authors: Rogers, Miranda J.; King, Taylor L.; Kim, Jaewhan; Adeyemi, Temitope F.; Higgins, Thomas F.; Maak, Travis G.
• Is Part Of: Journal of orthopaedic trauma. Volume 35:Issue 10(2021)
• Publication Date: 2021-10
• Subjects: femoral neck shaft angle -- neck shaft angle -- proximal femur fracture -- fixed angle constructs -- intertrochanteric fractures -- subtrochanteric fractures -- pertrochanteric fractures -- femoral neck fractures -- caput–collum–diaphyseal angle; Orthopedics -- Periodicals; Wounds and injuries -- Periodicals; Orthopedics -- Periodicals; Wounds and Injuries -- therapy -- Periodicals; Periodicals; 617.47044
• DOI: 10.1097/BOT.0000000000002069
• Languages: English
• ISSNs: 0890-5339

Abstract

Abstract : Objectives: To (1) assess interrater reliability of a novel technique for measurement of neck shaft angle (NSA); (2) use pelvic anteroposterior (AP) radiographs of unaffected hips to assess variability of NSA; and (3) evaluate the side-to-side variability of NSA to determine reliability of using the contralateral hip as a template. Design: Retrospective cohort study. Setting: Academic Level 1 regional trauma center. Patients/Participants: Four hundred six femora (203 patients) with standing AP pelvis radiographs were selected. Exclusions included lack of acceptable imaging, congenital abnormalities, or prior hip surgery. Intervention: An AP pelvis radiograph in the standing position. Main Outcome Measurements: Bilateral NSA measurements obtained in a blinded fashion between 2 reviewers. Pearson coefficients and coefficient of determination assessed correlations and variability between left and right NSA. Concordance correlation coefficients assessed the interrater reliability between measurements performed by the 2 reviewers. Results: Two hundred three patients (406 femora) were assessed. Male patients had a lower overall NSA mean of 131.56 degrees ± 4.74 than females with 133.61 degrees ± 5.17. There was no significant difference in NSA side-to-side in females ( P = 0.18), 0.3 degrees [95% confidence interval (−0.15 to 0.75)], or males ( P = 0.68), 0.19 degrees [95% confidence interval (−0.74 to 1.12)]. There was a strong linear relationship between left and right femora (r 2 = 0.70). Forty-one percent of patients fell within the 131–135 degrees range bilaterally. Eighty-eight percent of patients had <5 degrees difference in NSA bilaterally and 0% had >10 degrees difference. Conclusions: There is no significant variability between bilateral femora in males and females. Use of this measurement method and contralateral NSA for proximal femur fracture planning is supported.