DOS 2018

DOS Kongressen 2018 · 219 The lateral joint space width can be measured reliably with Telos valgus stress radiography in medial knee osteoarthritis Daan Koppens, Ole Gade Sørensen, Stig Munk, Jesper Dalsgaard, Søren Rytter, Solveig Kärk Abildtrup Larsen , Maiken Stilling, Torben Bæk Hansen Orthopedic Department, Regional Hospital of Holstebro; Orthopedic Department, Aarhus University Hospital; Radiology Department, Regional Hospital of Holstebro Background: Patient selection is important for a good clinical outcome after medial unicompartmental knee arthroplasty (UKA), and importantly, lateral compartment osteoarthritis (OA) must be excluded. Purpose / Aim of Study: To examine the reliability of valgus stress radiographs with the Telos stress device for assessment of lateral compartment degenera- tive changes in patients with medial osteoarthritis of the knee. Materials and Methods: A prospective reliability study was performed. Seventy-nine patients (80 knees) were included, and standardised valgus stress radiographs were obtained using the Telos stress device. Osteophytes and joint space narrowing (JSN) were graded using the OARSI atlas, and the joint space width (JSW) was measured in millimetres. Intra-and inter-rater reliability and test-retest reliability were determined. Weighted kappa was used to determine the reliability of osteophyte and JSN grading, and the intra-class correlation co- efficient was used for JSW. Findings / Results: Grading of osteophytes had an intra- and inter-rater reli- ability ranging from 0.40 to 0.83 on the medial side, and from 0.39 to 0.87 on the lateral side. Grading of medial JSN had an intra- and inter-rater reliability ranging from 0.62 to 0.84, and grading of lateral JSN had an intra- and inter- rater reliability ranging from 0.32 to 0.65. Intra- and inter-rater reliability of JSW ranged from 0.84 to 0.98 on the medial side, and from 0.59 to 0.89 on the lateral side. Test-retest reliability of JSW of the medial and lateral side ranged from 0.69 to 0.92. Conclusions: Evaluation of the lateral compartment on valgus stress radio- graphs is most reliable with measurement of the lateral JSW. Standardised val- gus stress radiographs taken with the Telos stress device are a reliable supple- ment in the clinical evaluation of patients with medial OA of the knee. 160.