Department of Orthopaedic Surgery, Division of Sports Medicine, Midwest Orthopaedics at Rush, Rush University Medical Center, Chicago, Illinois, U.S.A.
Sidney Kimmel Medical College, Philadelphia, Pennsylvania, U.S.A.
Arthroscopy. 2023 Aug;39(8):1815-1826.e1. doi: 10.1016/j.arthro.2023.01.104. Epub 2023 Feb 21.
To evaluate how the meniscotibial ligament (MTL) affects meniscal extrusion (ME) with or without concomitant posterior medial meniscal root (PMMR) tears and to describe how ME varied along the length of meniscus.
ME was measured using ultrasonography in 10 human cadaveric knees in conditions: (1) control, either (2a) isolated MTL sectioning, or (2b) isolated PMMR tear, (3) combined PMMR+MTL sectioning, and (4) PMMR repair. Measurements were obtained 1 cm anterior to the MCL (anterior), over the MCL (middle), and 1 cm posterior to the MCL (posterior) with or without 1,000 N axial loads in 0° and 30° flexion.
At 0°, MTL sectioning demonstrated greater middle than anterior (P < .001) and posterior (P < .001) ME, whereas PMMR (P = .0042) and PMMR+MTL (P < .001) sectioning demonstrated greater posterior than anterior ME. At 30°, PMMR (P < .001) and PMMR+MTL (P < .001) sectioning demonstrated greater posterior than anterior ME, and PMMR (P = .0012) and PMMR+MTL (P = .0058) sectioning demonstrated greater posterior than anterior ME. PMMR+MTL sectioning demonstrated greater posterior ME at 30° compared with 0° (P = .0320). MTL sectioning always resulted in greater middle ME (P < .001), in contrast with no middle ME changes following PMMR sectioning. At 0°, PMMR sectioning resulted in greater posterior ME (P < .001), but at 30°, both PMMR and MTL sectioning resulted in greater posterior ME (P < .001). Total ME surpassed 3 mm only when both the MTL and PMMR were sectioned.
The MTL and PMMR contribute most to ME when measured posterior to the MCL at 30° of flexion. ME greater than 3 mm is suggestive of combined PMMR + MTL lesions.
Overlooked MTL pathology may contribute to persistent ME following PMMR repair. We found isolated MTL tears able to cause 2 to 2.99 mm of ME, but the clinical significance of these magnitudes of extrusion is unclear. The use of ME measurement guidelines with ultrasound may allow for practical MTL and PMMR pathology screening and pre-operative planning.
评估半月板胫骨韧带（MTL）在伴有或不伴有后内侧半月板根（PMMR）撕裂的情况下如何影响半月板外突（ME），并描述 ME 沿半月板长度的变化情况。
在 10 个人体尸体膝关节中，在以下条件下使用超声测量 ME：（1）对照，分别为（2a）单独的 MTL 节段切除，或（2b）单独的 PMMR 撕裂，（3）同时切除 PMMR+MTL，以及（4）PMMR 修复。在 0°和 30°屈曲时，在 MCL 前 1 cm（前）、MCL 上（中）和 MCL 后 1 cm（后）进行测量，施加 1000 N 的轴向负荷。
在 0°时，MTL 节段切除显示出比前（P <.001）和后（P <.001）更明显的中间 ME，而 PMMR（P =.0042）和 PMMR+MTL（P <.001）节段切除显示出比前更明显的后 ME。在 30°时，PMMR（P <.001）和 PMMR+MTL（P <.001）节段切除显示出比前更明显的后 ME，而 PMMR（P =.0012）和 PMMR+MTL（P =.0058）节段切除显示出比前更明显的后 ME。与 0°相比，PMMR+MTL 节段切除在 30°时显示出更大的后 ME（P <.001）。MTL 节段切除始终导致更大的中间 ME（P <.001），而 PMMR 节段切除则无中间 ME 变化。在 0°时，PMMR 节段切除导致更大的后 ME（P <.001），但在 30°时，PMMR 和 MTL 节段切除均导致更大的后 ME（P <.001）。只有当 MTL 和 PMMR 同时切除时，总 ME 才超过 3 毫米。
在 30°屈曲时，MTL 和 PMMR 对 MCL 后测量的 ME 贡献最大。ME 大于 3 毫米提示同时存在 PMMR+MTL 病变。
被忽视的 MTL 病理学可能导致 PMMR 修复后 ME 持续存在。我们发现单独的 MTL 撕裂能够导致 2 至 2.99 毫米的 ME，但这些程度的外突的临床意义尚不清楚。使用超声测量 ME 指南可能允许对 MTL 和 PMMR 进行实际的病理筛查和术前规划。
