Biomechanics Laboratory-II Clinic, Rizzoli Orthopaedic Institute, Via Di Barbiano, 1/10, 40136, Bologna, Italy,
Knee Surg Sports Traumatol Arthrosc. 2014 Jun;22(6):1337-44. doi: 10.1007/s00167-013-2813-4. Epub 2013 Dec 14.
Subchondral bone edema is a common finding after cartilage treatment, but its interpretation is still debated. The aim of this study is to analyse the presence of edema after matrix-assisted autologous chondrocyte transplantation (MACT) for knee cartilage lesions at different follow-up times and its correlation with the clinical outcome.
Two hundred and forty-eight magnetic resonance imagings (MRIs) of patients treated with a hyaluronic acid-based MACT for lesions of the knee articular surface were considered. The MRIs belonged to 116 patients (mean age at surgery 28.6 ± 10.3 years, average defect size 2.4 ± 1.0 cm(2)), 57 affected by degenerative cartilage lesions, 27 traumatic and 32 were osteochondritis dissecans (OCD). MRI follow-up was performed from 6 to 108 months after treatment. Other than its presence or absence, the subchondral bone edema was evaluated using a 3-level grading considering extension and hyperintensity, and with the WORMS score edema classification. The IKDC subjective score was collected at the time of every MRI.
An analysis of the entire MRI group showed that edema is not constantly present through the follow-up, but presents a particular and well-defined trend. Edema was present within the first 2 years and was then markedly reduced or disappeared at 2 and 3 years (p = 0.044). Afterwards the level of edema increased again (p < 0.0005) and remained steadily present at medium/long-term follow-up. Patellar lesions presented significantly lower edema (p = 0.012), whereas OCD lesions presented more edema at all follow-up (p = 0.002) and a different trend, with an increasing level of edema over time. No correlation was found between edema and clinical outcome.
Edema after MACT is present during the first phases of cartilage maturation up to 2 years of follow-up, and then tends to disappear. However, after a few years, it tends to reappear. Less edema was found in the patella, whereas more edema was found in the OCD, where subchondral bone is primarily involved. Interestingly, the presence of edema was not correlated with a poorer clinical outcome. Whether this might be a prognostic factor at longer follow-up remains to be determined, but our results give some indication on what to expect on both MRI edema and clinical outcome after MACT.
Case series, Level IV.
软骨治疗后出现骨软骨下水肿是一种常见现象，但对其的解读仍存在争议。本研究旨在分析基质辅助自体软骨细胞移植（MACT）治疗膝关节软骨病变后不同随访时间的水肿存在情况及其与临床结果的相关性。
共分析了 116 例（平均手术年龄 28.6±10.3 岁，平均缺损面积 2.4±1.0cm2）接受基于透明质酸的 MACT 治疗的膝关节关节面病变患者的 248 份磁共振成像（MRI）。其中 57 例为退行性软骨病变，27 例为创伤性，32 例为剥脱性骨软骨炎（OCD）。治疗后 6-108 个月进行 MRI 随访。除了有无骨软骨下水肿外，还使用 3 级分级法评估骨软骨下水肿的延伸程度和信号强度，以及 WORMS 评分水肿分类。每次 MRI 时均采集 IKDC 主观评分。
对整个 MRI 组进行分析显示，骨软骨下水肿并非在整个随访过程中持续存在，而是呈现出一种特殊而明确的趋势。在最初的 2 年内存在水肿，然后在 2 年和 3 年时明显减少或消失（p=0.044）。之后，水肿水平再次升高（p<0.0005），并在中/长期随访中持续存在。髌骨病变的水肿程度明显较低（p=0.012），而 OCD 病变在所有随访中均存在更多的水肿（p=0.002），且具有不同的趋势，随着时间的推移，水肿水平逐渐升高。未发现水肿与临床结果之间存在相关性。
MACT 后，骨软骨下水肿在软骨成熟的最初阶段存在，持续至 2 年的随访时间，然后趋于消失。然而，几年后，它又开始出现。髌骨病变的水肿程度较低，而 OCD 病变的骨软骨下水肿程度较高，OCD 病变主要累及骨软骨下骨。有趣的是，水肿的存在与较差的临床结果无关。在更长的随访时间内，这种情况是否是一个预后因素仍有待确定，但我们的研究结果表明，在 MACT 后进行 MRI 水肿和临床结果的预测方面，有一些值得关注的地方。
病例系列，IV 级。
