Demange Marco Kawamura, Von Keudell Arvind, Gomoll Andreas Hans
University of São Paulo, São Paulo, Brazil.
Knee. 2013 Oct;20(5):360-3. doi: 10.1016/j.knee.2013.05.010. Epub 2013 Jun 23.
Partial resection of the lateral meniscus can lead to iatrogenic instability of the remnant, resulting in recurrent locking episodes. Due to the innocuous appearance on MRI, the etiology of the locking episodes can be difficult to determine, leading to delays in diagnosis and treatment of this entity.
We describe two cases of unstable lateral meniscus posterior horn remnants after previous partial meniscectomy for meniscal tear. Both patients initially presented with lateral pain without mechanical symptoms and were treated with partial meniscectomies. They developed new locking symptoms after initial arthroscopies, and worsened after repeat arthroscopy with removal of additional meniscal tissue. Both patients had their locking symptoms questioned and been accused of malingering by previous physicians due to the benign MRI findings. They were treated successfully by completion meniscectomy.
Few studies investigate atypical locking symptoms secondary to undiagnosed lateral meniscus tears. No previous case reports have described knee locking after partial lateral meniscectomy secondary to iatrogenic posterior horn remnants instability.
New onset mechanical symptoms after partial resection of the lateral meniscus body can be due to posterior horn instability with subluxation under the femoral condyle. This entity appears benign on MRI, requiring a high index of suspicion to make the diagnosis.
外侧半月板部分切除术可导致残余半月板医源性不稳定，引发反复交锁发作。由于磁共振成像（MRI）表现不明显，交锁发作的病因可能难以确定，导致该病症的诊断和治疗延迟。
我们描述了两例因半月板撕裂先前接受部分半月板切除术后外侧半月板后角残余不稳定的病例。两名患者最初均表现为外侧疼痛但无机械性症状，接受了部分半月板切除术治疗。他们在初次关节镜检查后出现了新的交锁症状，在再次关节镜检查并切除更多半月板组织后症状加重。由于MRI表现正常，两名患者的交锁症状均受到质疑，且被之前的医生指责为装病。他们通过半月板全切术获得了成功治疗。
很少有研究调查未诊断出的外侧半月板撕裂继发的非典型交锁症状。此前没有病例报告描述过因医源性后角残余不稳定导致部分外侧半月板切除术后膝关节交锁的情况。
外侧半月板体部部分切除术后新出现的机械性症状可能是由于后角不稳定伴股骨髁下半脱位所致。该病症在MRI上表现正常，需要高度怀疑才能做出诊断。
