Department of Orthopaedic Surgery, Stanford University, Palo Alto, California 93405, USA.
Arthroscopy. 2009 Sep;25(9):1011-8. doi: 10.1016/j.arthro.2009.04.068.
The purpose of this study was to develop a method of femoral fixation for complex revision anterior cruciate ligament (ACL) reconstructions that would avoid a staged bone grafting approach. We evaluated the use of a calcium phosphate cement as a structural bone void filler that would allow for a single-stage revision ACL reconstruction with initial biomechanical properties equivalent to standard autologous bone-patellar tendon-bone primary ACL reconstruction.
We tested 11 matched pairs of fresh-frozen cadaveric knees (N = 22). Controls were treated with autologous bone-patellar tendon-bone primary ACL reconstruction fixed with bioabsorbable interference screws with a 1-mm back wall. The contralateral knee of each pair had a large bone void created that would hamper subsequent femoral fixation to simulate revision ACL reconstruction conditions. This defect was filled with calcium phosphate cement arthroscopically. After solidification, the femoral tunnel was drilled through the bone void filler and native bone with a 1-mm back wall, allowing anatomic positioning. The autologous graft was then placed and fixed with a bioabsorbable interference screw. Specimens were then tested in an MTS machine (MTS Systems, Eden Prairie, MN) for load to failure according to a standard protocol and compared with matched controls.
Failure loads for the control group averaged 312 N (standard deviation [SD], 127 N) and were not significantly different compared with the calcium phosphate cement revision group, which averaged 301 N (SD, 95 N) (P = .80). Failure occurred at the femoral bone block in both groups but without screw pullout.
Statistical analysis failed to show a significant difference between the control group and the group undergoing structural bone void filler revision in this biomechanical evaluation of initial fixation strength.
This technique may allow surgeons to perform a single-stage revision ACL reconstruction in the presence of a contained bone void and avoid the need for a staged procedure if clinical studies verify long-term incorporation of the bone void filler.
本研究旨在开发一种用于复杂翻修前交叉韧带（ACL）重建的股骨固定方法，避免分期植骨。我们评估了磷酸钙骨水泥作为结构性骨缺损填充物的应用，该方法可用于一期翻修 ACL 重建，初始生物力学性能与标准自体骨-髌腱-骨（BPTB）初次 ACL 重建相当。
我们测试了 11 对匹配的新鲜冷冻尸体膝关节（N=22）。对照组采用自体 BPTB 初次 ACL 重建，使用带 1mm 后壁的可吸收干扰螺钉固定。每对膝关节的对侧膝关节均形成大的骨缺损，以模拟翻修 ACL 重建条件，从而妨碍随后的股骨固定。该缺损通过关节镜用磷酸钙骨水泥填充。凝固后，在骨缺损填充物和原生骨上用带 1mm 后壁的钻头钻股骨隧道，允许进行解剖定位。然后将自体移植物放置并用可吸收干扰螺钉固定。然后按照标准方案在 MTS 机器（MTS Systems，Eden Prairie，MN）上进行失效负荷测试，并与匹配的对照组进行比较。
对照组的失效负荷平均值为 312N（标准差[SD]，127N），与磷酸钙骨水泥翻修组的 301N（SD，95N）平均值相比无显著差异（P=0.80）。两组均在股骨骨块处发生失效，但无螺钉拔出。
在这项初始固定强度的生物力学评估中，统计分析未显示对照组与结构性骨缺损填充物翻修组之间有显著差异。
如果临床研究证实骨缺损填充物的长期结合，该技术可能允许外科医生在存在包含性骨缺损的情况下进行一期翻修 ACL 重建，并避免分期手术的需要。
