The correlation between clinical and radiological severity of osteoarthritis of the knee

Abstract

Introduction: Primary osteoarthritis (OA) is a common cause of knee pain. Appropriate management of knee OA is based on clinical and radiological findings. Pain, deformity, and functional impairments are major clinical factors considered along with radiological findings when making management decisions. Differences in management strategies might exist due to clinical and radiological factors. This study aims at finding possible associations between clinical and radiological observations. Methods: A prospective cross-sectional study of 52 patients with primary osteoarthritis of the knee managed conservatively at a tertiary hospital arthroplasty clinic was conducted for three months. English speaking patients with primary OA were identified and included in this study. Pain and functional impairment were assessed using Wong-Baker Faces pain scale, The Knee Society Score (KSS), and Western Ontario and McMaster Osteoarthritis Index (WOMAC). The Body Mass Index (BMI) of all participants was measured. Standard two views plain radiographs were used for radiographic grading of the OA. Anonymized radiographs were presented to two senior consultant orthopaedic surgeons who graded the OA using Kellgren and Lawrence (KL) and Ahlbäck classification systems. The severity of the functional impairment and pain score was then compared to the radiological grading. Results: The average age of our participants was 63 ± 9 years. Their average BMI was 34.9 ± 8.4 kg/m2, median self-reported pain, total WOMAC, and pain WOMAC scores were 8, 60, and 13, respectively. We observed no significant correlation between BMI and pain scores. Inter-rater reliability for KL and Ahlbäck grading was strong. There was no significant correlation between WOMAC scores and the radiological grades. Conclusion: There was no correlation between pain and functional scores, patient factors and radiological severity of OA of the knee.

An Algorithmic Approach to Understanding Osteoarthritic Knee Pain

“…Finally, systems such as the KL grade fail to capture the range of reported pain and function at various levels of knee joint degeneration [17][18][19][20] . Figure 2 demonstrates this in a violin plot of patient pain compared with KL grade.…”

“…Clinicians may not be as good at this as we think, even when it comes to the first step of determining the degree to which pain originates from structural factors within the knee 15 . Clinicians rely on the Kellgren-Lawrence (KL) grade to gauge the structural severity of osteoarthritis by radiographs 16 , yet the KL grade does not explain pain very well [17][18][19][20] . It is not uncommon for clinicians to see patients with severe degenerative changes on radiographs (high KL grades) and relatively little pain, as well as those with relatively mild degenerative changes on radiographs (low KL grades) and severe pain.…”

Preoperative Ahlbäck radiographic classification grade significantly influences clinical outcomes of double level osteotomy for osteoarthritic knees with severe varus deformity

“…Previous studies have widely used the K-L grading system to determine the severity of osteoarthritis, but since most subjects who underwent DLO presented K-L grade 4 changes in this study, the use of the Ahlbäck classification system was able to more effectively differentiate the osteoarthritic severity. In addition, the Ahlbäck classification was better suited for radiological evaluation of this patient population than the K-L classification because it focuses more on joint space narrowing and bone attrition [ 41 ]. In the statistical analysis of this study, improvement in clinical score was less satisfactory in knees with Ahlbäck grade 3 or 4.…”

“…Therefore, most knees with joint space narrowing that undergo osteotomy are classified as either grade 3 or 4. However, Ahlbäck proposed another radiological classification system for osteoarthritic knees in which K-L grade 4 can be further subdivided into Ahlbäck grades 2–5 [ 3 , 41 ]. Since candidates for DLO present severe varus deformity with apparent joint space narrowing, use of the Ahlbäck classification may provide a clearer relationship between radiological osteoarthritic grade and surgical outcome.…”

Short- to Mid-Term Outcomes in Arthroscopic Debridement of the Knee: A Prospective Case Series

“…A systematic review and meta-analysis demonstrated significant improvement in pain, movement, and quality of life in the short term, between three and six months [ 26 ]. The United States of America has a relatively young cohort of osteoarthritic patients with more than half, below the age of 60 years [ 28 ]. In our series, patients below 56 years had significant improvement in their OKS.…”