Hoshikawa Atsuto, Nakamura Haruhiko, Takei Ryota, Matsumoto Risa, Saita Kazuo
Department of Orthopaedic Surgery, Tohto Bunkyo Hospital, Tokyo, Japan.
Department of Orthopaedic Surgery, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
Arthrosc Sports Med Rehabil. 2023 Nov 10;5(6):100818. doi: 10.1016/j.asmr.2023.100818. eCollection 2023 Dec.
To compare the degree of medial meniscal extrusion (MME) between knees with medial meniscus posterior root tear (MMPRT) and degenerative tears of the medial meniscus using ultrasonography (US) in different limb positions and to identify the findings characteristic of MMPRT.
The study group comprised 25 subjects with MMPRT (group RT), 25 subjects with degenerative medial meniscal tears (group D), and 25 knees with no abnormalities of the medial meniscus (MM) on magnetic resonance imaging (MRI) (group C) whose age was ≥40 years. MME was evaluated using US in the supine, figure-4, feet-dangling, and standing positions. The MME was evaluated by the actual measurement values and the relative values to the MME in the supine position. The differences in the MME among the 3 groups in each limb position were analyzed using one-way analysis of variance. < .05 was considered significant.
The actual MME values were largest in group RT in all 4 limb positions. When changing the limb position from the supine to the figure-4, the actual MME increased from 3.8 ± 0.8 mm to 5.5 ± 1.3 mm in group RT, whereas it decreased from 3.4 ± 1.1 mm to 1.8 ± 1.2 mm in group D, showing the most significant difference in MME of the figure-4 position between the 2 groups ( < .001). In group RT, 88% of knees had the maximum MME in the figure-4 position. In group D, 60% of knees had the maximum MME in the standing position and only 2 knees (8%) had the maximum MME in the figure-4 position.
The increase in MME from the supine to the figure-4 position was a characteristic finding of MMPRT but not degenerative tears.
Level III, case-control study.
使用超声（US）在不同肢体位置比较内侧半月板后根部撕裂（MMPRT）的膝关节与内侧半月板退变撕裂之间的内侧半月板挤出（MME）程度，并确定MMPRT的特征性表现。
研究组包括25例MMPRT患者（RT组）、25例内侧半月板退变撕裂患者（D组）和25例磁共振成像（MRI）显示内侧半月板（MM）无异常的膝关节（C组），年龄均≥40岁。在仰卧位、4字位、垂腿位和站立位使用US评估MME。MME通过实际测量值以及相对于仰卧位MME的相对值进行评估。使用单因素方差分析分析3组在每个肢体位置的MME差异。P < 0.05被认为具有统计学意义。
在所有4个肢体位置，RT组的实际MME值最大。当肢体位置从仰卧位变为4字位时，RT组的实际MME从3.8±0.8 mm增加到5.5±1.3 mm，而D组则从3.4±1.1 mm减少到1.8±1.2 mm，两组在4字位的MME差异最为显著（P < 0.001）。在RT组中，88%的膝关节在4字位时MME最大。在D组中，60%的膝关节在站立位时MME最大，只有2例膝关节（8%）在4字位时MME最大。
从仰卧位到4字位MME增加是MMPRT而非退变撕裂的特征性表现。
III级，病例对照研究。
