PURPOSE To use magnetic resonance imaging (MRI) to investigate the knee joint of children following arthroscopic fixation of osteochondral lesions using bioabsorbable nails and to correlate these imaging findings with time from arthroscopic treatment and with risk factors at the time of imaging. MATERIALS AND METHODS Our study included postarthroscopic MRI studies from 58 children (mean age at arthroscopy, 13.8 + 2.1 years) who have undergone bioabsorbable nail fixation of unstable osteochondral lesions between February 1, 2011 and September 30, 2017. All studies were retrospectively reviewed for broken nails, intra-articular debris, and internal knee derangement. Demographic information and information pertaining to active symptoms was obtained from both MRI questionnaire that was completed at the time of the study and clinical note that preceded the study. Marginal logistic regression models estimated using generalized estimating equations (GEE) were used to identify factors associated with a broken nail and joint effusion. RESULTS A total of 104 postoperative studies were reviewed, which included 60 with symptoms and 44 without symptoms. Nail breakage was present in 38 (36.6%) studies and associated with presence of symptoms (OR 2.43, p = 0.036) and effusion (OR 2.76, p = 0.025). An effusion was present in 40 (38.5%) studies which decreased with increasing time from treatment (OR 0.89, p = 0.007) and increased with symptoms (OR 10.87, p < 0.001). Meniscal tear was present on 8 (7.7%) and chondral irregularity on 14 (13.5%) studies. CONCLUSION Broken nail, effusion, and less commonly, meniscal tears and chondral irregularity, are all complications that can arise following fixation of osteochondral lesions with bioabsorbable nails. MRI can serve as a valuable tool in assessing these complications.

中文翻译：

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关节镜下用可生物降解钉固定骨软骨病变后的小儿膝关节磁共振评估。

目的使用磁共振成像（MRI）研究使用生物可吸收指甲进行关节镜固定骨软骨病变的儿童的膝关节，并将这些成像结果与关节镜治疗时间和成像时的危险因素相关联。材料与方法我们的研究包括2011年2月1日至2017年9月30日对58例儿童（关节镜平均年龄13.8 + 2.1岁）进行了生物吸收性钉固定不稳定骨软骨病变的儿童的关节镜检查后MRI研究。指甲断裂，关节内碎屑和膝盖内部错乱。人口统计学信息和有关活动症状的信息均从研究时完成的MRI问卷和研究前的临床记录中获得。使用广义估计方程（GEE）估计的边际逻辑回归模型用于确定与指甲断裂和关节积液相关的因素。结果对104项术后研究进行了回顾，包括60项有症状和44项无症状。有38项研究（36.6％）存在指甲破裂现象，并且与出现症状（OR 2.43，p = 0.036）和积液（OR 2.76，p = 0.025）有关。在40例研究中出现了积液（38.5％），随着治疗时间的延长而减少（OR 0.89，p = 0.007），而随着症状的增加而增加（OR 10.87，p <0.001）。半月板撕裂出现在8（7。7％）和14个（13.5％）研究中的软骨异常。结论指甲破损，积液，以及半月板撕裂和软骨异常，都是生物可吸收钉固定骨软骨病变后可能引起的并发症。MRI可作为评估这些并发症的宝贵工具。