The Role of High Resolution Ultrasound in the Assessment of Knee Osteoarthritis

Abstract
Background: Osteoarthritis (OA) is a common musculoskeletal
disease with high prevalence worldwide. Knee OA
is primary diagnosed using conventional radiography, however,
changes of articular cartilage or menisci cannot be directly
assessed using conventional radiology. Ultrasound (US) can
be used to assess soft tissue degeneration directly.
Aim of Study: The aim of this study is to evaluate the
efficacy of High Resolution Ultrasound (HRUS) in the assessment
of structural abnormalities found in knee osteoarthritis.
Patients and Methods: The study was conducted upon 20
patients with knee OA (12F, 8M; mean age 53 years), each
subject was evaluated for the presence of medial and lateral
femoral cartilage thinning, medial and lateral femoral and
tibial osteophytes, medial and lateral meniscal degeneration,
joint effusion and Baker's cyst using ultrasound and MRI,
considering MRI as a reference standard.
Results: The overall sensitivity of the ultrasound in the
detection of knee OA parameters was good (89.3%), the
overall accuracy was excellent (90%), the overall specificity
was excellent (93.1%). The Positive Predictive Value (PPV)
and the Negative Predictive Value (NPV) were 98.3 and 65.9
respectively. The p-value was highly significant (<0.01) when
comparing assessment of knee osteoarthritis parameters between
ultrasound and MRI.
Conclusion: Ultrasound assessment of the knee joint is
an accurate imaging method for detection of knee osteoarthritis
parameters including medial and lateral femoral articular
cartilage thinning, medial and lateral osteophytes, medial and
lateral meniscal degeneration, joint effusion and Baker's cyst.
Thus, Knee ultrasound can be used as a complementary
imaging technique to radiography, especially when MRI is
not available, to assess tissue-specific structural OA degeneration
not detected by conventional radiographs.