三维骨建模在全膝关节置换术中韧带平衡的作用

目的探讨以三维骨建模为基础、无需影像的计算机辅助系统在人工全膝关节置换术(totalknee arthroplasty,TKA)中韧带平衡的作用。方法2002年11月～2003年6月,采用后稳定型人工全膝关节,在Ceravision无需影像资料的三维骨建模系统导航监控下,辅助完成TKA21例。男5例,女16例,年龄64～79岁,平均72.4岁。其中2例既往行胫骨近端截骨术,1例行股骨远端截骨术。14例膝内翻,7例膝外翻。术前下肢全长X线正位片测量,内翻13°～外翻13°,平均2.36°;膝关节X线正位片测量,应力下内翻平均8.47°(内翻2°～内翻20°),应力下外翻平均3.63°(内翻7°～外翻12°)。结果术中导航系统测量,额面内翻12°～外翻10°,平均3.33°,与术前比较差异有统计学意义(P<0.05);额面应力下内翻平均6.47°(内翻0°～内翻24°),应力下外翻平均4.32°(内翻8°～外翻15°),与术前比较差异有统计学意义(P<0.05)。术毕导航系统测得膝内外翻平均0.175°(内翻2°～外翻3°),而术后下肢全长X线正位片测量平均0.3°(内翻3.5°～外翻1.5°),二者差异无统计学意义(P>0.05)。术后3个月关节活动度为105～130°,平均115°,膝关节额面松弛度0.2～0.5cm,平均0.27cm。人工膝关节胫、股骨假体取得满意的对位置入和韧带平衡,无关节失稳和髌骨脱位等并发症发生。结论以三维骨建模为基础、无需影像的Ceravision系统,具有三维立体定位、优化截骨,并通过旋转对位和韧带松解获得伸屈膝关节等距间隙与韧带平衡稳定的作用,近期临床疗效满意,可在TKA中常规使用。

BONE MORPHING SYSTEM FOR LIGAMENT BALANCEING IN TOTAL KNEE ARTHROPLASTY

OBJECTIVE: To investigate effectiveness of applying the Bone Morphing based image-free computer-assisted system for the ligament balancing management in the total knee arthroplasty (TKA). METHODS: Between November 2002 and June 2003, twenty-one posterior stabilized total knee prostheses (Ceraver, France) were implanted in 21 patients using the Bone Morphing based image-free Ceravision system. This cohort included 5 men and 16 women with an average age of 72.4 years, two undergoing high tibial osteotomy and 1 undergoing distal femoral osteotomy before. The preoperative deviation was measured by the full-length AP X-rays. The knees were in varus deviation in 14 patients and in valgus deviation in 7 patients, with an average of 2.36 degrees (varus 13 deegrees-valgus 13 degrees). The frontal X-rays of the knee were assessed, the mean value of the varus force-stress test was 8.47 degrees (varus 2 degrees-varus 20 degrees), and the mean value of the valgus force-stress test was 3. 63 degrees (varus 7 degrees-valgus 12 degrees). RESULTS: With the Ceravision-recorded data, the intraoperative alignment was assessed, the mean lower limb axis was 3.33 degrees (varus 12 degrees-valgus 10 degrees), and compared with the preoperative data, the difference was significant (P < 0.05); the mean value of the varus force-stress test was 6. 47 degrees (varus 0 degree - varus 24 degrees), the mean value of the valgus force-stress test was 4.32 degrees (varus 8 degrees-valgus 15 degrees), and compared with the preoperative data, the difference was significant (P < 0.05). The post-prosthetic alignment on Ceravision with a deviation of 0.175 degrees (varus 2 degrees-valgus 3 degrees) was compared with the postoperative alignment by the full-length AP X-rays, with a deviation of 0.3 degrees (varus 3.5 degrees-valgus 1.5 degrees), the difference wasn't significant (P > 0.05). The clinical check-up performed 3 months after operation showed that the average range of movement (ROM) was 115 degrees (105-130 degrees), the mean frontal laxity was 0.27 mm (0.2-0.5 mm). The femoral and tibial components were implanted in the satisfactory 3 dimensional position without ligament imbalance in all the patients, and there were no instability or patella complications. CONCLUSION: Utilization of the Bone Morphing based image-free computer-assisted system can achieve an accurate component 3 dimensional alignment, optimal bone resection, optimal control of surgical decision in releasing the soft tissues, rotating the femoral component to gain an extension/flexion rectangular gap, and managing the ligament balancing so as to achieve a satisfactory initial clinical outcome. This system can be routinely used in the TKA.