MRI evaluation of internal derangement of knee

Abstract

Internal derangement of knee joint constitutes a major source of morbidity in patients attending orthopedic outpatients department of our hospital. It includes a group of disorders due to disruption of normal functioning of ligaments and menisci of knee joint leading to persistent or intermittent signs and symptoms such as pain, instability, or abnormal mobility of the knee. MRI would be an noninvasive non operator dependent effective modality for early detection of these pathologies and has very high negative predictive value. MRI of knee would save us many unnecessary diagnostic arthroscopy, which is an invasive procedure with associated risks. Fifty patients with clinically suspected internal derangement of knee (37 men, 13 women; mean age 33.2 yrs) were included in this prospective study. They were evaluated with detailed clinical history and clinical examinations and were subsequently subjected to imaging of knee using 1.5 T MRI PHILIPS ACHIEVA MRI machine. Sequences used were axial, sagittal and coronal PD Fat Sat; sagittal, axial and coronal T2 FSE and sagittal T1 FSE. This study included 50 patients with clinical suspicion of internal derangement of knee. Thirty-seven were men and 13 women with mean age of 33.2 years. Acute traumatic injury to knee exceeded the non-traumatic etiology. ACL was the commonest ligament to be injured with complete tear being more common than partial tear. LCL was the commonest ligament to be torn in association with ACL. Indirect signs of ACL injury were evaluated and helped to corroborate the tears. Meniscal injury was common in medial meniscus and predominantly involved the posterior horn. This was also the commonest site of lateral meniscal tear. Certain pattern of associations of injuries was found such as ACL tear with postero-lateral corner injury and O'Donoghue's triad.