A new protocol for obtaining whole leg radiographs with excellent reproducibility

Roel J.H Custers,Willem Paul Gielis,Harrie Weinans,Mario Hevesi,Nienke Van Egmond,H Chien Nguyen

doi:10.1016/j.jcjp.2022.100042

Abstract

IntroductionWhole Leg Radiographs (WLR) are the gold standard for diagnosing malalignment and for pre-operative osteotomy planning. Positioning can affect the reproducibility of the measured hip knee angle (HKA), resulting in insufficient diagnostics and preoperative plans. We developed an easy-to-use WLR protocol by standardizing patient positioning and focusing on reproducibility. ObjectivesThis study aims on testing this reproducibility of the novel WLR protocol. MethodsThis study enrolled 30 patients for a test-retest analysis. Each patient underwent two bilateral WLRs on the same day using the investigated positioning protocol. Three observers measured the HKA, mechanical medial proximal tibial angle (mMPTA), mechanical lateral distal femoral angle (mLDFA), and joint line convergence angle (JLCA) on the two radiographs. Twice each, with one week between. ResultsThe intra-observer and inter-observer reliabilities were excellent, with intraclass correlation coefficients (ICCs) between 0.990 and 0.996. The ICCs between the measured HKA (0.985), mMPTA (0.922), and mLDFA (0.903) on the two separate radiographs were excellent. The ICC between the JLCA measured on the first and second WLR was moderate with 0.632. The mean absolute error between the HKA, mMPTA, mLDFA, and JLCA measurements on the first and second WLR were respectively: 0.442°, 0.783°, 0.828°, and 0.794°. ConclusionsThe investigated novel WLR positioning protocol produced excellent and reproducible HKA measurements, with clinically acceptable degrees of error. We recommend applying this easy-to-use protocol when obtaining WLRs for osteotomy planning. Physicians still need to be aware of possible rotational and fixed flexion deformities in the lower limb present on WLRs and during physical examination.

Highlights

Whole Leg Radiographs (WLR) are the gold standard for diagnosing malalignment and for pre-operative osteotomy planning
Patients were recruited at the University Medical Centre (UMC) Utrecht Mobility Clinic, which is a tertiary orthopaedic referral centre for knee joint preserving treatments, including cartilage repair techniques, osteotomies, and knee joint distraction.[25,26,27]
Wilcoxon signed-rank tests revealed no significant differences between all lower limbs and males and/or females, osteoarthritis,chondral lesions, and osteotomy surgery in terms of hip knee angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and joint line convergence angle (JLCA)

Summary

Introduction

Whole Leg Radiographs (WLR) are the gold standard for diagnosing malalignment and for pre-operative osteotomy planning. Positioning can affect the reproducibility of the measured hip knee angle (HKA), resulting in insufficient diagnostics and preoperative plans. We developed an easy-to-use WLR protocol by standardizing patient positioning and focusing on reproducibility. Osteoarthritis (OA) is one of the most common chronic medical conditions and is a leading cause of disability and pain globally.[1] Amongst adults above 60 years of age, the prevalence of symptomatic knee OA is approximately 10% in men and 18% in women.[2] Resultant pain and loss of function can be debilitating, with high associated socioeconomic burden, estimated to cost between 1.0% and 2.5% of the gross domestic product.[3]. JID: JCJP H.C. Nguyen, N. van Egmond, M.

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