带陶瓷涂层的钛合金关节表面假体治疗羊膝关节软骨全层缺损的实验研究

Resurfacing full thickness defects of focal cartilage in the knee with titanium alloy implant with ceramic coating： an experimental study in sheep

目的探讨带陶瓷涂层的钛合金关节表面假体治疗羊膝关节软骨令层缺损的效果。方法取12只成年雌性小尾寒羊，其中9只羊的双侧股骨内侧髁制造成直径为7mm、深为2mm的软骨全层缺损，将这18侧膝关节随机分为3组（n=6）：A组植入带陶瓷涂层的钛合金关节表面假体；B组植入钛合金关节表面假体；C组不植入任何材料；另外3只未手术羊的双侧膝关节作为正常对照组（D组，n=6）。术后6个月取材，行X线片检查，测量假体关节表而的粗糙度；记录实验羊膝关节O’-Driscoll评分、膝关节软骨Outerbridge评分及改良的Mankin评分；显微CT扫描和组织学观察似休周旧新生骨及软骨的生长情况。结果术后6个月，B组假体关节表面的粗糙度（0．178±0.063）显著大于A组（0．034±0．006），差异有统计学意义（P〈0．05）。A组O’Driscoll评分[（4．7±0．6）分]显著高于B组[（3．8±0．3）分]和C组[（3，7±0．3）分]，内侧胫骨平台软骨Outerbridge评分[（1．0±0．4）分l及改良的Mankin评分[（2．3±0．3）分]显著低于B组[（2．5±0．3）、（7．2±1．0）分]和C组[（2．0±0．3）、（5．2±0．8）分]，差异均有统计学意义（P〈0．05）；而A组与D组比较差异均无统计学意义（P〉0．05）。显微CT扫描和组织学观察显示A组、B组假体与周围骨结合稳定，新生软骨覆盖在假体的关节表而，关节表而光滑、平整。结论带陶瓷涂层的钛合金关节表而假体治疗羊膝关节软骨损伤的效果良好。

Objective To investigate the efficacy of resurfacing full thickness defects of focal knee cartilage with a titanium alloy implant with ceramic surface coating in sheep. Methods Twelve male sheep were used in this experiment. Standardized defects of focal knee cartilage （7 mm in diameter and 2 mm in depth） were created in the medial femoral condyle at both knees in 9 sheep which were randomly assigned into 3 groups （ n =6）. In group A, titanium alloy implants with ceramic surface coating were inserted into the defects. In group B, the defects were treated with titanium alloy implants. In group C, the defects were left untreated. The 6 untreated knee joints in another 3 sheep served as a control group （group D）. The animals were saerificed at 6 months. X-ray examinations were performed immediately after operation anti at 6 months. Surface roughness of the implants was measured before implantation and at 6 months. The knee joints were evalualed according to O＇ Driscoll score. The damage to opposing cartilage was evaluated according to Outerbridge score and modified Mankin score. Micro-CT analysis and histological observation were used to assess stability of the implants and the cartilage surrounding the implants. Results At 6 months, the surface roughness value in group B （0. 178 ±0. 063） was significantly higher than in group A （0. 034 ± 0. 006） （ P 〈 0.05）. Group A had significantly higher O＇Driscoll score （4. 7 ±0. 6） than group B （3.8 ±0. 3） and group C （3.7 ± 0.3） （ P 〈 0. 05）. The Outerbridge score （ 1.0 ± 0.4） and modified Mankin score （2.3 ± 0. 3） for the medial tibial plateau in group A were signifieantly lower than those in group B （2.5 ±0.3 and 7.2 ± 1.0, respectively） and in group C （2.0 ±0. 3 and 5.2 ±0. 8） （ P 〈 0.05）. There were no significant differences between groups A and D （ P 〉 0. 05）. Micro-CT scan and histological observation showed that all the implants were mechanically stable and new-born cartilage covered the surface of implants well in groups A and B. Conclusion Titanium alloy implants with ceramic surface coating may favor resurfacing full thickness defects of focal knee cartilage in sheep.