Center for Shoulder, Elbow and Sports Medicine, 622 W 168th Street, PH-1117, New York, NY 10032, USA.
Clin Orthop Relat Res. 2011 Apr;469(4):1082-8. doi: 10.1007/s11999-010-1580-5.
Arthroscopically assisted anterior cruciate ligament reconstruction using a bioabsorbable tibial fixation screw is occasionally complicated by pretibial cyst formation. The few case reports describing pretibial cyst formation noted several graft types and fixation techniques, making it difficult to establish one etiology. Some literature suggests cysts form from communication between the joint and pretibial area leading to extravasation of joint fluid, maturing into a cyst. We propose the development of cysts after PLLA screw use may be related to a foreign body reaction.
QUESTIONS/PURPOSES: We propose this foreign body reaction (1) relates to the biochemical breakdown of bioabsorbable materials; and (2) differs from cystic formations resulting from joint communication.
We retrospectively reviewed seven patients who developed pretibial cysts at least 2 years after original primary ACL reconstruction surgery. MRI was used to visualize the extent of cystic formation. Cysts were treated by débridement with specimens sent for histologic analysis. Cyst appearance had a 3-year incidence of 5%.
No cyst had an infectious etiology. In all cases, the tibial screw outline was present on MRI, although intraoperatively, the screw was substantially decomposed. Grafts were well incorporated and none of the knees demonstrated anterior laxity. Histologically, cyst material contained fragments of PLLA surrounded by foamy histiocytes, suggesting a foreign body reaction. No cysts recurred.
Tibial cysts occur in a subset of patients undergoing ACL reconstruction using a bioabsorbable PLLA interference screw. We suspect they arise from a foreign body response to the screw breakdown. Removal is well tolerated.
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
关节镜辅助前交叉韧带重建术中使用可吸收胫骨固定螺钉偶尔会导致胫骨前囊肿形成。少数描述胫骨前囊肿形成的病例报告提到了几种移植物类型和固定技术，因此很难确定一个病因。一些文献表明，囊肿是由关节和胫骨前区域之间的沟通引起的，导致关节液渗出，成熟为囊肿。我们提出 PLLA 螺钉使用后囊肿的形成可能与异物反应有关。
问题/目的：我们提出这种异物反应（1）与可吸收材料的生化分解有关；（2）与关节沟通引起的囊性形成不同。
我们回顾性分析了 7 例在初次 ACL 重建手术后至少 2 年出现胫骨前囊肿的患者。MRI 用于观察囊肿形成的范围。通过清创术治疗囊肿，并将标本送检进行组织学分析。囊肿外观的 3 年发生率为 5%。
没有囊肿具有感染性病因。在所有情况下，MRI 上均可见胫骨螺钉轮廓，尽管术中螺钉已严重分解。移植物均良好融合，且无膝关节出现前向松弛。组织学上，囊肿内物质包含 PLLA 碎片，周围有泡沫状组织细胞，提示异物反应。没有囊肿复发。
在接受使用可吸收 PLLA 干扰螺钉的 ACL 重建术的患者中，会出现胫骨囊肿。我们怀疑它们是由螺钉分解引起的异物反应引起的。切除后耐受性良好。
IV 级，治疗性研究。有关证据水平的完整描述，请参见作者指南。
