Christiaan R Oosthuizen1, Tsuneari Takahashi2, Mack Rogan3, Christian H Snyckers4, Duwayne P Vermaak5, Gareth G Jones6, Andrew Porteous7, Innocent Maposa8, Hemant Pandit9. 1. Private Orthopaedic Practice, Johannesburg, South Africa; Division of Orthopaedic Surgery, University of the Witwatersrand, Johannesburg, South Africa. 2. Department of Orthopaedic Surgery, Jichi Medical University, Shimotsuke, Tochigi, Japan; Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, United Kingdom. 3. Johannesburg, South Africa. 4. Department of Orthopaedic Surgery, University of Pretoria, Pretoria, South Africa. 5. Private Orthopaedic Practice, Pretoria, South Africa. 6. MSk Lab, Imperial College, London, United Kingdom. 7. Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, United Kingdom. 8. Division of Epidemiology and Biostatistics, Faculty of Health Sciences, Wits School of Public Health, University of the Witwatersrand, Johannesburg, South Africa. 9. Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, United Kingdom.
Abstract
BACKGROUND: The aim of this study is to validate the Knee Osteoarthritis Grading System (KOGS) of progressive osteoarthritic degeneration for the tri-compartmental knee. This system defines the site and severity of osteoarthritis to determine a specific knee arthroplasty. METHODS: The radiographic sequence for KOGS includes standing coronal (anteroposterior), lateral, 30° skyline patella, 15° and 45° Rosenberg and stress views in 20° of flexion. Cohen's kappa and related agreement statistical methods were used to assess the level of concordance of the 7 evaluators between A and B cohorts for each evaluator and also against the actual arthroplasty used. Sensitivity and specificity was also assessed for the KOGS in identifying true partial knee arthroplasties (PKAs) and total knee arthroplasties (TKAs) as decided from the cohort A evaluations. RESULTS: From a cohort of 330 patients who were included in the study, 71 (22.5%) underwent a TKA procedure, 258 (78.2%) a PKA, and 1 (0.3%) was neither a TKA nor PKA. KOGS was able to identify true PKAs (sensitivity) in the range of 92.2%-98.5% across all the different evaluators. The KOGS method was able to identify a PKA or a TKA with an accuracy ranging from 92% to 98.8% across all different evaluators. The surgical results after 20 months are at least comparable with the expected average in the academic literature. CONCLUSION: The KOGS classification provides a reliable and accurate tool to assess suitability of an individual patient for undergoing PKA or TKA.
BACKGROUND: The aim of this study is to validate the Knee Osteoarthritis Grading System (KOGS) of progressive osteoarthritic degeneration for the tri-compartmental knee. This system defines the site and severity of osteoarthritis to determine a specific knee arthroplasty. METHODS: The radiographic sequence for KOGS includes standing coronal (anteroposterior), lateral, 30° skyline patella, 15° and 45° Rosenberg and stress views in 20° of flexion. Cohen's kappa and related agreement statistical methods were used to assess the level of concordance of the 7 evaluators between A and B cohorts for each evaluator and also against the actual arthroplasty used. Sensitivity and specificity was also assessed for the KOGS in identifying true partial knee arthroplasties (PKAs) and total knee arthroplasties (TKAs) as decided from the cohort A evaluations. RESULTS: From a cohort of 330 patients who were included in the study, 71 (22.5%) underwent a TKA procedure, 258 (78.2%) a PKA, and 1 (0.3%) was neither a TKA nor PKA. KOGS was able to identify true PKAs (sensitivity) in the range of 92.2%-98.5% across all the different evaluators. The KOGS method was able to identify a PKA or a TKA with an accuracy ranging from 92% to 98.8% across all different evaluators. The surgical results after 20 months are at least comparable with the expected average in the academic literature. CONCLUSION: The KOGS classification provides a reliable and accurate tool to assess suitability of an individual patient for undergoing PKA or TKA.
Authors: Christiaan Rudolf Oosthuizen; Catherine Van Der Straeten; Innocent Maposa; Christian Hugo Snyckers; Duwayne Peter Vermaak; Sebastian Magobotha Journal: Int Orthop Date: 2019-09-12 Impact factor: 3.075
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Authors: Jacob Fyhring Mortensen; Kristian Breds Geoffroy Mongelard; Dimitar Ivanov Radev; Andreas Kappel; Lasse Enkebølle Rasmussen; Svend Erik Østgaard; Anders Odgaard Journal: J Orthop Date: 2021-05-12