The Investigation Of Diagnostic Value For The Osteoarthritis Of The Knee With High-frequency Ultrasound Examination

Objective:To evaluate the value and clinical significance of high-frequency ultrasound examination in the diagnosis of knee osteoarthritis. Also, to assess the correlation of grading cartilage degeneration of the knee between the high-frequency ultrasound examination and the observation by eye during the operation.Methods:Both High-frequency ultrasound examination and knee roentgenography were used for detecting grading cartilage degeneration of the knee in 35 cases with osteoarthritis and the detected results of both methods were compared.The thickness of articular cartilage of the knees were measured by ultrasound both in 35 patients and 10 normal people. The measure spot of the cartilage was 7 parts of the joint surface, they were intercondylar groove, the front,the weight-bearing and the posterior of femoral condyle. The results were compared.Thirty-five patients with osteoarthritis of the knee (36 knees) who underwent arthroscopic surgery or total knee arthroplasty were included in the study. The articular cartilages of all knees covering the center of the intercondylar groove (CIG), medial trochlearportion (MTP), lateral trochlearportion (LTP), the weight-bearing aspect of medial femoral condyle (MFC) and lateral femoral condyle (LFC) were examined by High-frequency ultrasound. The ultrasound examination results were compared with the arthroscopic or surgery findings. Results:In detecting the changes of effusion, synovial hypertrophy, knee cartilage affection, destruction of bone under cartilage, popliteal cyst and meniscus apomorphosis, the ultrasonography had higher resolution power than X-ray film. The detection rate of above changes by ultrasonography was 88.6%, 85.7%, 92.9%, 58.6%, 41.4% and 44.3% respectively. The difference between the detection rates of ultrasonography and X-ray was significant (P<0.05). Both ultrasonography and MRI could discover changes of cartilage, synovial membrane, meniscus of knee joint well. The difference between the two methods was not significant (P>0.05).The thickness of articular cartilage of the knees was difference in the difference location. In normal group, the outcome of ultrasound measurement for the center of the intercondylar groove cartilage was 2.41±0.37mm, the thickness of cartilage in the front of medial and lateral femoral condylar was 1.22±0.11mm,1.31±0.14mm respectively, that in the weight-bearing of MFC and LFC was 1.31±0.16mm,1.42±0.16mm, that in the posterior of MFC and LFC was 1.34±0.17mm,1.45±0.13mm. The difference between the thickness of articular cartilage of MFC and LFC was significant (P>0.05).The outcome of ultrasound measurement the center of the intercondylar groove cartilage was 1.94±0.28mm. The thickness of cartilage in the front,the weight-bearing and the posterior of LFC was 1.02±0.20mm,0.88±0.27mm,0.99±0.20mm respectively, that in the front,the weight-bearing and the posterior of MFC was 0.98±0.18mm,0.81±0.27mm,0.95±0.21mm. The difference of the thickness of articular cartilage of the knees between the osteoarthritis patients and normal people was significant (P>0.05).Operation grading of knee cartilage degenerative lesion was grade 0 in 27 articular surfaces, gradeⅠin 23, gradeⅡin 43, gradeⅢin 40 and grade in 47.Cartilage degeneration grades determined with Ultrasound were correlated with these determined during the operation. The correlation coefficients were 0.806 (P<0.05). Conclusions:1. High-frequency ultrasound is useful in the diagnosis of knee osteoarthritis.2. The articular cartilage thickness of the knee can be accurately measured by ultrasound.3. High-frequency ultrasound is reliable for grading articular cartilage degeneration of knee.