Magnetic resonance imaging after surgical transposition defines the anteroposterior location of the rectus muscle pulleys
Magnetic resonance imaging after surgical transposition defines the anteroposterior location of the rectus muscle pulleys
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DOI：
10.1016/s1091-8531(99)70088-1
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发表时间：
1999-02-01
期刊：
影响因子：
1.6
通讯作者：
Demer, JL
中科院分区：
文献类型：
--
作者：
Clark, RA;Rosenbaum, AL;Demer, JL
简介：结缔组织滑车作为眼外直肌的功能起点，并在转位手术后限制眼外直肌后腹的侧滑。在滑轮前方，EOM路径明显移位以到达其换位插入。眼外肌路径中从最小后向位移到最大前向位移的拐点应定义转位后眼外肌滑轮的前后位置。研究方法：对6例行直肌转位术的患者，在手术前后在垂直于眼眶长轴的平面上连续获得其整个前后范围的横断面磁共振图像。4例患者接受了垂直直肌完全肌腱宽度外侧移位术治疗外直肌麻痹。其中两名患者通过缝线加强移位，将移位肌肉的颞缘向后固定到邻近外直肌边缘的巩膜上。1例患者行水平直肌全腱宽度移位术治疗上级上直肌麻痹。1例患者行双侧外直肌肌腱全宽转位术治疗“A”型内斜视。相对于轨道的面积质心定义EOM的路径。滑轮位置推断EOM路径。通过从每个图像平面的术后滑轮位置中减去术前滑轮位置，获得EOM滑轮位置的术后变化。结果：对于所有患者，术后眼外肌腹位置的变化相对较小，位于球-视神经交界处后方。然而，与未接受加固缝线的类似患者相比，2例接受后方加固缝线的外展肌麻痹患者的后垂直直肌路径位移明显更大。对于水平移位的垂直直肌和垂直移位的外直肌，眼外肌路径的拐点开始于球-视神经交界处前方3 mm处。对于上位转位的内直肌和外直肌，拐点开始于球-视神经交界处前方6 mm处。结论：眼外肌滑车的前后位置可以通过分析眼外肌移位来确定。通过后鼻孔扩大转位使眼外肌滑车的位移远大于非扩大转位。
Introduction: Connective tissue pulleys serve as the functional origins of the rectus extraocular muscles (EOMs) and constrain the sideslip of the posterior EOM bellies after transposition surgery. Anterior to the pulleys, EOM paths appreciably displace to reach their transposed insertions. The inflection points in the EOM paths from minimal posterior displacement to maximal anterior displacement should define the anteroposterior location of the EOM pulleys after transposition. Methods: Contiguous cross-sectional magnetic resonance images were obtained in planes perpendicular to the long axis of the orbit over its entire anteroposterior extent before and after operation in 6 patients who underwent rectus muscle transposition surgery. Four patients underwent full tendon width transposition of the vertical rectus muscles laterally for lateral rectus palsy. Two of these patients had augmentation of the transposition with sutures that fixated the temporal margins of the transposed muscles posteriorly to the-sclera adjacent to the borders of the lateral rectus muscle. One patient underwent full tendon width transposition of the horizontal rectus muscles superiorly for superior rectus palsy. One patient underwent full tendon width transposition of both lateral rectus muscles inferiorly for "A" pattern esotropia. Paths of EOMs were defined relative to the area centroid of the orbit. Pulley locations were inferred from EOM paths. The postoperative change in EOM pulley location was obtained by subtracting the preoperative pulley location from the postoperative pulley location for each image plane. Results: For all patients, th postoperative change in EOM belly location was relatively small posterior to the globe-optic nerve junction. The 2 patients with abducens palsy who underwent placement of posterior augmentation sutures, however, demonstrated a significantly larger displacement of the posterior vertical rectus paths compared with similar patients who did not receive augmentation sutures. For a II horizontally transposed vertical rectus muscles and inferiorly transposed lateral rectus muscles, the inflection of the EOM path began 3 mm anterior to the globe-optic nerve junction. For the superiorly transposed medial rectus muscle and lateral rectus muscle, the inflection began 6 mm anterior to the globe-optic nerve junction. Conclusions: The anteroposterior locations of the EOM pulleys can be defined by analysis of EOM displacement after transposition surgery. Augmentation of transpositions by posterior suturing displaces the EOM pulleys substantially more than nonaugmented transpositions.