Simon C Mears1, A Cecilia Severin2, Junsig Wang3, Jeff D Thostenson4, Erin M Mannen5, Jeffrey B Stambough1, Paul K Edwards6, C Lowry Barnes1. 1. Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR. 2. Department of Neuromedicine and Movement Science, Center for Elite Sports Research, Norwegian University of Science and Technology, Trondheim, Norway. 3. Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR; Department of Sports Medicine, Kyung Hee University, Yongin-si, Gyeonggi-do, South Korea. 4. Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, AR. 5. Boise State University, Mechanical and Biomedical Engineering Department, Boise, ID. 6. Bowen Hefley Orthopaedics, Blandford Office Building, Little Rock, AR.
Abstract
BACKGROUND: The clinical examination for laxity has been considered a mainstay in evaluation of the painful knee arthroplasty, especially for the diagnosis of instability. More than 10 mm of anterior-posterior (AP) translation in flexion has been described as important in the diagnosis of flexion instability. The inter-observer reliability of varus/valgus and AP laxity testing has not been tested. METHODS: Ten subjects with prior to total knee arthroplasty (TKA) were examined by 4 fellowship-trained orthopedic knee arthroplasty surgeons. Each surgeon evaluated each subject in random order and was blinded to the results of the other surgeons. Each surgeon performed an anterior drawer test at 30 and 90 degrees of flexion and graded the instability as 0-5 mm, 5-10 mm or >10 mm. Varus-valgus testing was also graded. Motion capture was used during the examination to determine the joint position and estimate joint reaction force during the examination. RESULTS: Inter-rater reliability (IRR) was poor at 30 and 90 degrees for both the subjective rater score and the measured AP laxity in flexion (k = 018-0.22). Varus-valgus testing similarly had poor reliability. Force applied by the rater also had poor IRR. CONCLUSION: Clinical testing of knee laxity after TKA has poor reliability between surgeons using motion analysis. It is unclear if this is from differences in examiner technique or from differences in pain or quadriceps function of the subjects. Instability after TKA should not be diagnosed strictly by clinical testing and should involve a complete clinical assessment of the patient.
BACKGROUND: The clinical examination for laxity has been considered a mainstay in evaluation of the painful knee arthroplasty, especially for the diagnosis of instability. More than 10 mm of anterior-posterior (AP) translation in flexion has been described as important in the diagnosis of flexion instability. The inter-observer reliability of varus/valgus and AP laxity testing has not been tested. METHODS: Ten subjects with prior to total knee arthroplasty (TKA) were examined by 4 fellowship-trained orthopedic knee arthroplasty surgeons. Each surgeon evaluated each subject in random order and was blinded to the results of the other surgeons. Each surgeon performed an anterior drawer test at 30 and 90 degrees of flexion and graded the instability as 0-5 mm, 5-10 mm or >10 mm. Varus-valgus testing was also graded. Motion capture was used during the examination to determine the joint position and estimate joint reaction force during the examination. RESULTS: Inter-rater reliability (IRR) was poor at 30 and 90 degrees for both the subjective rater score and the measured AP laxity in flexion (k = 018-0.22). Varus-valgus testing similarly had poor reliability. Force applied by the rater also had poor IRR. CONCLUSION: Clinical testing of knee laxity after TKA has poor reliability between surgeons using motion analysis. It is unclear if this is from differences in examiner technique or from differences in pain or quadriceps function of the subjects. Instability after TKA should not be diagnosed strictly by clinical testing and should involve a complete clinical assessment of the patient.
Authors: M Murer; A L Falkowski; A Hirschmann; F Amsler; Michael T Hirschmann Journal: Knee Surg Sports Traumatol Arthrosc Date: 2020-03-31 Impact factor: 4.342
Authors: Jaap S Luttjeboer; Menno R Bénard; Koen C Defoort; Gijs G van Hellemondt; Ate B Wymenga Journal: J Arthroplasty Date: 2016-07-21 Impact factor: 4.757
Authors: Humera Khan; Peter S Walker; Joseph D Zuckerman; James Slover; Fredrick Jaffe; Raj J Karia; Joo H Kim Journal: J Arthroplasty Date: 2012-11-02 Impact factor: 4.757