OBJECTIVE: To describe the MR features of mucoid degeneration of the anterior cruciate ligament (ACL) in a series of patients with MRI findings that were mistaken for tears in the majority of cases but who were found to have an intact ligament at arthroscopy. We will suggest a pathologic entity corresponding to this finding and describe some characteristic features that can be used to identify this entity on MRI. DESIGN: A retrospective analysis of 10 MRI examinations of the knee was performed after arthroscopic evaluation. Prearthroscopic MRI findings had been interpreted as a tear in six patients prospectively and in the remaining four the diagnosis of mucoid degeneration was suggested and ultimately proven. All patients had an intact ACL by preoperative clinical examination, examination under anesthesia, and at arthroscopy. RESULTS: MRI examinations demonstrated an ill-defined ACL, greater in girth than the normal ligament and characterized by increased signal on all sequences. The high-signal ligament was oriented in the normal direction of the ACL. The overall appearance of the ligament was retrospectively described as like a celery stalk. Arthroscopy demonstrated mechanically intact ligaments with a normal to expanded external appearance. Probing of three of the ligaments caused a material to be expressed and pathologic evaluation resulted in the diagnosis of cystic, mucoid degeneration. CONCLUSION: Mucoid degeneration and an intact ACL can be suspected when an apparently thickened and ill-defined ligament with increased signal intensity on all sequences is identified in a patient with a clinically intact ligament.
OBJECTIVE: To describe the MR features of mucoid degeneration of the anterior cruciate ligament (ACL) in a series of patients with MRI findings that were mistaken for tears in the majority of cases but who were found to have an intact ligament at arthroscopy. We will suggest a pathologic entity corresponding to this finding and describe some characteristic features that can be used to identify this entity on MRI. DESIGN: A retrospective analysis of 10 MRI examinations of the knee was performed after arthroscopic evaluation. Prearthroscopic MRI findings had been interpreted as a tear in six patients prospectively and in the remaining four the diagnosis of mucoid degeneration was suggested and ultimately proven. All patients had an intact ACL by preoperative clinical examination, examination under anesthesia, and at arthroscopy. RESULTS: MRI examinations demonstrated an ill-defined ACL, greater in girth than the normal ligament and characterized by increased signal on all sequences. The high-signal ligament was oriented in the normal direction of the ACL. The overall appearance of the ligament was retrospectively described as like a celery stalk. Arthroscopy demonstrated mechanically intact ligaments with a normal to expanded external appearance. Probing of three of the ligaments caused a material to be expressed and pathologic evaluation resulted in the diagnosis of cystic, mucoid degeneration. CONCLUSION:Mucoid degeneration and an intact ACL can be suspected when an apparently thickened and ill-defined ligament with increased signal intensity on all sequences is identified in a patient with a clinically intact ligament.
Authors: Wing Hung Alex Ng; James Francis Griffith; Esther Hiu Yee Hung; Bhawan Paunipagar; Billy Kan Yip Law; Patrick Shu Hang Yung Journal: World J Orthop Date: 2011-08-18
Authors: Pieter Van Dyck; Filip M Vanhoenacker; Jan L Gielen; Lieven Dossche; Jozef Van Gestel; Kristien Wouters; Paul M Parizel Journal: Skeletal Radiol Date: 2010-10-08 Impact factor: 2.199
Authors: Francois Lintz; Nicolas Pujol; Philippe Boisrenoult; Kevin Bargoin; Philippe Beaufils; David Dejour Journal: Knee Surg Sports Traumatol Arthrosc Date: 2011-02-18 Impact factor: 4.342