Albrecht Christian, Reuter Carla-Antonia, Stelzeneder David, Zak Lukas, Tichy Brigitte, Nürnberger Sylvia, Boesmueller Sandra, Marlovits Stefan, Trattnig Siegfried, Hajdu Stefan, Aldrian Silke
Department of Trauma-Surgery, Medical University of Vienna, Vienna, Austria.
Austrian Cluster for Tissue Regeneration, Vienna, Austria.
Am J Sports Med. 2017 Aug;45(10):2238-2246. doi: 10.1177/0363546517707499. Epub 2017 Jun 2.
Matrix-associated autologous chondrocyte transplantation (MACT) has been an effective therapy for large, full-thickness cartilage lesions for years. However, little is known about how graft maturation is affected by characteristics of transplanted chondrocytes.
To investigate the influence of gene expression of chondrocytes at the time of transplantation on MRI outcomes up to 2 years after MACT.
Case series; Level of evidence, 4.
This study included 25 patients with 27 symptomatic traumatic defects of articular cartilage, who had undergone MACT in the knee. Postoperative MRI examinations were conducted at 3, 6, 12, and 24 months after surgery. Biochemical graft maturation was assessed by measuring T2 relaxation time values of the transplant and healthy native cartilage areas. The MOCART (magnetic resonance observation of cartilage repair tissue) score was used to evaluate the morphological quality of regeneration tissue. Gene expression (collagen type I, collagen type II, aggrecan, versican, and interleukin-1β) was determined by real-time polymerase chain reaction (PCR) in transplant residuals at the time point of transplantation and was correlated with MRI outcomes using Spearman's rank correlation coefficient. A Friedman test with post hoc analysis (Wilcoxon signed rank test) conducted with a Bonferroni correction was applied to compare scores at different time points.
T2 relaxation time of regeneration tissue improved from a mean ± SD of 74.6 ± 20.1 milliseconds at 3 months to 47.9 ±13.3 milliseconds at 24 months ( P < .003). These values were similar to the T2 relaxation times of the native surrounding cartilage (50.9 ± 15 ms). The calculated T2 index (ratio of regeneration tissue to native cartilage) improved from 1.63 ± 0.76 at 3 months to 1.0 ± 0.4 at 24 months ( P < .011). The MOCART score increased from 51.6 ± 15 points to 72.4 ± 12.2 points ( P < .001). Improvement of the T2 index over time significantly correlated with aggrecan, COL1A1, COL2A1, and versican expression ( r = 0.9, P < .001; r = 0.674, P < .012; r = 0.553, P < .05; and r = 0.575, P < .04, respectively). No correlation was found for IL-1β.
These data demonstrate that matrix production in transplanted chondrocytes affects maturation of MACT grafts in MRI 2 years after surgery.
多年来，基质相关自体软骨细胞移植（MACT）一直是治疗大面积全层软骨损伤的有效方法。然而，对于移植软骨细胞的特性如何影响移植物成熟，人们知之甚少。
研究移植时软骨细胞的基因表达对MACT术后长达2年的MRI结果的影响。
病例系列；证据等级，4级。
本研究纳入了25例患有27个有症状的膝关节创伤性软骨缺损的患者，这些患者均接受了膝关节的MACT治疗。术后分别在3、6、12和24个月进行MRI检查。通过测量移植物和健康天然软骨区域的T2弛豫时间值来评估生化移植物成熟度。采用MOCART（软骨修复组织的磁共振观察）评分来评估再生组织的形态质量。在移植时间点通过实时聚合酶链反应（PCR）测定移植残余物中的基因表达（I型胶原蛋白、II型胶原蛋白、聚集蛋白聚糖、多功能蛋白聚糖和白细胞介素-1β），并使用Spearman等级相关系数将其与MRI结果相关联。采用经Bonferroni校正的Friedman检验及事后分析（Wilcoxon符号秩检验）来比较不同时间点的评分。
再生组织的T2弛豫时间从术后3个月时的平均±标准差74.6±20.1毫秒改善至24个月时的47.9±13.3毫秒（P <.003）。这些值与周围天然软骨的T2弛豫时间（50.9±15毫秒）相似。计算得出的T2指数（再生组织与天然软骨的比值）从3个月时的1.63±0.76改善至24个月时的1.0±0.4（P <.011）。MOCART评分从51.6±15分增加至72.4±12.2分（P <.001）。随着时间推移，T2指数的改善与聚集蛋白聚糖、COL1A1、COL2A1和多功能蛋白聚糖的表达显著相关（r分别为0.9，P <.001；r为0.674，P <.012；r为0.553，P <.05；r为0.575，P <.04）。未发现与白细胞介素-1β有相关性。
这些数据表明，移植软骨细胞中的基质产生会影响术后2年MRI检查中MACT移植物的成熟度。
