Salvati F, Rossi F, Limbucci N, Pistoia M L, Barile A, Masciocchi C
Department of Radiology, San Salvatore Hospital, University of L'Aquila, Italy.
J Sports Med Phys Fitness. 2008 Dec;48(4):483-7.
Mucoid degeneration of the anterior cruciate ligament (ACL) is a pathological state not yet well morphologically defined, involving people without history of knee instability or significant trauma, and causing important pain. The aim of this study was to define the histopathological and radiographic features of this pathological condition.
Analysis of 1 215 knee magnetic resonance (MR) examinations found 64 cases (5.3%) of ACL mucoid metaplastic-degeneration (MMD), subsequently all subjects underwent surgical and arthroscopic validation. MR examinations have been performed using a dedicate system provided with a permanent magnet of 0.18 T and with a dedicate coil of 12 cm of field of view (FOV) or an high field instrument with 1.5 T. Radiological criteria to define ACL MMD were based essentially on increased signal intensity in T2W sequences and in STIR ones, as in T1W scans the ligament showed an intermediate signal.
ACL MMD was diagnosed in 36 males and 28 females, with a mean age of 44 years. ''Segmentary MMD'' was found in 11 subjects (17.2%) commonly affecting the postero-lateral bundle of the ligament without femoral or tibial spongious mucoid intrusion. ''Total MMD'' (involving the entire ligament and accompanied with femoral or tibial intrusion) was found in 53 subjects (82.8%).
The comparison between histopathological and MR findings suggests that the commonly called ACL mucoid degeneration (ACL MD) should be better defined as mucoid metaplastic degeneration (MMD).
前交叉韧带（ACL）黏液样变性是一种形态学上尚未明确界定的病理状态，累及无膝关节不稳定或重大创伤史的人群，并引起严重疼痛。本研究的目的是明确这种病理状况的组织病理学和影像学特征。
对1215例膝关节磁共振（MR）检查进行分析，发现64例（5.3%）ACL黏液样化生变性（MMD），随后所有受试者均接受手术和关节镜验证。MR检查使用配备0.18T永磁体和12cm视野（FOV）专用线圈的专用系统或1.5T的高场设备进行。定义ACL MMD的放射学标准主要基于T2加权序列和短TI反转恢复（STIR）序列中信号强度增加，因为在T1加权扫描中韧带显示中等信号。
诊断出36例男性和28例女性患有ACL MMD，平均年龄44岁。11名受试者（17.2%）出现“节段性MMD”，通常影响韧带的后外侧束，无股骨或胫骨海绵状黏液样浸润。53名受试者（82.8%）出现“完全性MMD”（累及整个韧带并伴有股骨或胫骨浸润）。
组织病理学和MR检查结果的比较表明，通常所称的ACL黏液样变性（ACL MD）应更好地定义为黏液样化生变性（MMD）。
