Diagnostic accuracy of ultrasonography in traumatic meniscal injury

ABSTRACT

Ultrasonography is a feasible inexpensive and accurate method for evaluating musculoskeletal injuries, which can be used as the first complementary diagnostic method. US is more sensitive than radiology when evaluating cartilage damage. [Buchman and Fjaramillo 2004] The common cause of knee pain and disability are tears in medial and lateral menisci. To determine accuracy of US in diagnosis of meniscal tears in middle aged patients in relation to MRI. Forty patients [27males and 13 females] with traumatic knee injury after one month of trauma to the knee. were selected from outpatient clinic of rheumatology and physical medicine and rehabilitation department of Bab-Elshareya university hospital. They were subjected to history taking, clinical examination including local [inspection, palpation, range of motion] and special tests as McMurray and Appley tests. Also ultrasonographic examination of the knees was done to evaluate the menisci and magnetic resonance imaging of the affected knees was done as a gold standard. This study was done on forty patients [27 males and 13 females] with their age ranged from 15 and 40 with mean age was [26 +/- 5] years. They were evaluated within one month of injury. All patients were subjected to full history taking, clinical examination, and US and MRI examination of affected knees. Swelling was found in 27[68%] of patients, stiffness was present in 28 [70%] of patients, giving way was present in 25[62%], snapping in 26[65%] and locking was present in 9[22%]of patients. Signs include effusion in 27 [68%] tender medial meniscus [97%] tender lateral meniscus27 [68%] tender popliteal fossa 31[77%], limited flexion in 18[45%] and limited extension in 14 [35%] of patients. Appley test was positive in all patients while McMurray test was positive only in 37 [92%] of patients. MRI examination showed tears in medial menisci in 35 patients and tears in lateral menisci in 15 patients. Ultrasonography had shown tears in 33 of 35 MRI+ve patients with medial tears [94.3%]-ve in 2 [5.7%]menisci, in15 lateral meniscal tears, ultrasonography showed tears in 14[92.9%] and was incorrect in only one [7.12%] meniscus Sensitivity, specificity, positive and negative predictive value of ultrasonography for medial tears were 89%, 66%, 97%, and 66.6% respectively. Regarding lateral meniscus it was 93% 76%, 70%, and 95% respectively. Ultrasonography is an easy, feasible, real-time, and an accurate imaging modality for diagnosis of post traumatic meniscal tears, It has a good correlation with MRI results. This suggests that it can be a useful imaging modality for the diagnosis of traumatic meniscal injuries