title: Validation of gait analysis with dynamic radiostereometric analysis (RSA) in patients operated with total hip arthroplasty.
abstract: We simultaneously examined 14 patients with OTS and dynamic radiostereometric analysis (RSA) to evaluate the accuracy of both skin- and a cluster-marker models. The mean differences between the OTS and RSA system in hip flexion, abduction, and rotation varied up to 9.5° for the skin-marker and up to 11.3° for the cluster-marker models, respectively. Both models tended to underestimate the amount of flexion and abduction, but a significant systematic difference between the marker and RSA evaluations could only be established for recordings of hip abduction using cluster markers (p = 0.04). The intra-class correlation coefficient (ICC) was 0.7 or higher during flexion for both models and during abduction using skin markers, but decreased to 0.5-0.6 when abduction motion was studied with cluster markers. During active hip rotation, the two marker models tended to deviate from the RSA recordings in different ways with poor correlations at the end of the motion (ICC ≤0.4). During active hip motions soft tissue displacements occasionally induced considerable differences when compared to skeletal motions. The best correlation between RSA recordings and the skin- and cluster-marker model was found for studies of hip flexion and abduction with the skin-marker model. Studies of hip abduction with use of cluster markers were associated with a constant underestimation of the motion. Recordings of skeletal motions with use of skin or cluster markers during hip rotation were associated with high mean errors amounting up to about 10° at certain positions. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1515-1522, 2017.
authors: Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University, SE 413 45, Göteborg, Sweden.
authors: Roland
authors: R
authors: Zügner
authors: Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University, SE 413 45, Göteborg, Sweden.
authors: Roy
authors: R
authors: Tranberg
authors: Department of Economics, Institute of Communication in Statistics, University of Gothenburg, Gothenburg, Sweden.
authors: Vera
authors: V
authors: Lisovskaja
authors: Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University, SE 413 45, Göteborg, Sweden.
authors: Bita
authors: B
authors: Shareghi
authors: Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University, SE 413 45, Göteborg, Sweden.
authors: Johan
authors: J
authors: Kärrholm
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D005684:Gait; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D059869:Radiostereometric Analysis / Q000379:methods*
keywords: 3D validation; dynamic validation; hip arthroplasty; hip kinematic; radiostereometric analysis