Barber F Alan, Dockery William D
Plano Orthopedic and Sports Medicine Center, Plano, Texas 75093, USA.
Arthroscopy. 2008 Apr;24(4):441-7. doi: 10.1016/j.arthro.2007.10.004.
The purpose of this study was to evaluate the long-term in vivo degradation of biodegradable interference screws made of poly-L-lactic acid (PLLA) and beta-tricalcium phosphate (beta-TCP).
Twenty patients undergoing patellar tendon autograft anterior cruciate ligament reconstruction fixed at both the femur and tibia with beta-TCP-PLLA screws at least 44 months earlier were evaluated by physical, radiographic, and computed tomography (CT) evaluations. This study was approved by the institutional review board. Lysholm, Tegner, Cincinnati, and International Knee Documentation Committee scores were also obtained. CT data were measured in Hounsfield units.
We evaluated 13 male and 7 female patients at a mean of 50 months after surgery (range, 44 to 56 months). CT scans and radiographs showed the bone plug fused to the tunnel wall with no beta-TCP-PLLA screw remaining. The screws were replaced with clearly calcified non-trabecular material, denser than soft tissue. Osteoconductivity was present in 75% of the tunnels and complete in 10%. No positive pivot-shift tests were found. Lysholm, Tegner, and Cincinnati scores improved from 60.4, 3.7, and 53.3, respectively, preoperatively to 90.8, 5.8, and 86.4, respectively, at follow-up. The mean side-to-side difference determined by use of the KT arthrometer (MEDmetric, San Diego, CA) was 0.4 mm.
The beta-TCP-PLLA interference screw (Bilok; ArthroCare, Sunnyvale, CA) completely degraded, and no remnant was present 4 years after insertion. Osteoconductivity was confirmed by CT scans at 75% of the screw sites and completely filled the site in 10%. The addition of beta-TCP to PLLA results in a biocomposite interference screw that is osteoconductive.
Level IV, therapeutic case series.
本研究旨在评估由聚-L-乳酸（PLLA）和β-磷酸三钙（β-TCP）制成的可生物降解干涉螺钉的长期体内降解情况。
对至少44个月前接受自体髌腱前交叉韧带重建且股骨和胫骨均用β-TCP-PLLA螺钉固定的20例患者进行体格检查、影像学检查和计算机断层扫描（CT）评估。本研究经机构审查委员会批准。还获得了Lysholm、Tegner、辛辛那提和国际膝关节文献委员会评分。CT数据以亨氏单位测量。
我们评估了13例男性和7例女性患者，平均术后50个月（范围44至56个月）。CT扫描和X线片显示骨栓与隧道壁融合，无β-TCP-PLLA螺钉残留。螺钉被明显钙化的非小梁材料替代，比软组织密度高。75%的隧道存在骨传导性，10%完全骨传导。未发现阳性轴移试验。Lysholm、Tegner和辛辛那提评分分别从术前的60.4、3.7和53.3提高到随访时的90.8、5.8和86.4。使用KT关节测量仪（MEDmetric，圣地亚哥，加利福尼亚州）测定的平均两侧差异为0.4mm。
β-TCP-PLLA干涉螺钉（Bilok；ArthroCare，森尼韦尔，加利福尼亚州）完全降解，植入4年后无残留。CT扫描证实75%的螺钉部位有骨传导性，10%的部位完全被填充。在PLLA中添加β-TCP可形成具有骨传导性的生物复合材料干涉螺钉。
IV级，治疗性病例系列。
