Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, USA.
Am J Sports Med. 2013 Jan;41(1):73-9. doi: 10.1177/0363546512464482. Epub 2012 Nov 13.
There is still little known regarding the effects of meniscus resection size on tibiofemoral stability.
To determine if partial medial meniscectomy of the posterior horn significantly alters tibiofemoral stability as measured by the anterior-posterior (AP) position and laxity of the medial femoral condyle.
Controlled laboratory study.
Five cadaveric knees were dissected to the capsule, preserving all ligaments and the quadriceps tendon. Each specimen was first tested on a rig where the AP position and laxity of the medial femoral condyle were measured while a range of forces was applied from full extension to 90° of flexion. Magnetic resonance imaging (MRI) at 3 tesla was then performed for baseline measurements of the meniscus before partial meniscectomy. Arthroscopic partial medial meniscectomy aimed at 30% of the posterior horn was then performed, followed by repeat mechanical testing and MRI. The sequence was then repeated for arthroscopic partial meniscectomy aimed at 60% and 100% of the posterior horn of the medial meniscus.
The MRI analysis demonstrated that 22% ± 9% of the original width of the posterior horn was removed at the first resection, 46% ± 11% was removed at the second resection, and the third resection was 100% removal of the posterior horn for all specimens. After 22% resection, no significant difference in AP laxity was observed. A statistically significant increase in AP laxity was observed with 46% resection under a 500-N compressive load compared with the intact meniscus. After full resection, significant increases in AP laxity were observed under a 50-N compressive load compared with the intact and 22% and 46% resections. The 22% resection had similar AP positions as the intact knee, whereas the 46% resection and 100% removal of the posterior horn had statistically further posterior AP positions than the intact knee.
Partial medial meniscectomy with ≥46% resection of the original width of the posterior horn significantly altered the AP position of the medial femoral condyle and also increased laxity.
These mechanical changes may lead to abnormal cartilage loading and early osteoarthritis.
关于半月板切除大小对胫股稳定性的影响，目前知之甚少。
确定后角部分内侧半月板切除术是否会显著改变胫骨股骨稳定性，通过前-后（AP）位置和内侧股骨髁的松弛度来测量。
对照实验室研究。
将 5 个尸体膝关节解剖至囊，保留所有韧带和股四头肌肌腱。每个标本首先在一个夹具上进行测试，在夹具上施加从完全伸展到 90°屈曲的一系列力，测量内侧股骨髁的 AP 位置和松弛度。然后在 3T 磁共振成像（MRI）下进行半月板的基线测量，然后进行部分半月板切除术。然后进行关节镜下内侧半月板部分切除术，目标是后角的 30%，然后重复机械测试和 MRI。然后对内侧半月板后角的 60%和 100%进行关节镜下部分切除术，重复该序列。
MRI 分析表明，第一次切除时，后角的原始宽度切除了 22%±9%，第二次切除时切除了 46%±11%，第三次切除时所有标本的后角均完全切除。切除 22%后，AP 松弛度无明显差异。与完整半月板相比，在 500N 压缩负荷下，46%切除时 AP 松弛度显著增加。完全切除后，与完整半月板和 22%、46%切除相比，在 50N 压缩负荷下，AP 松弛度显著增加。22%切除后的 AP 位置与完整膝关节相似，而 46%切除和后角 100%切除后的 AP 位置比完整膝关节有统计学上的进一步后移。
后角原始宽度≥46%的部分内侧半月板切除术显著改变了内侧股骨髁的 AP 位置，并增加了松弛度。
这些力学变化可能导致软骨负荷异常和早期骨关节炎。
