单、双运动单元固定治疗胸腰椎骨折的疗效比较

Outcomes of two types of short-segment pedicle screw fixation for thoracolumbar fractures

目的比较单运动单元与双运动单元固定治疗胸腰椎压缩性骨折及不完全爆裂骨折（AO分型为A1型和A3型）的疗效，探讨单运动单元固定的可行性。方法通过前瞻性研究方法，选取A1型和A3型胸腰椎骨折患者141例。按随机数字法将两型骨折患者随机分为单运动单元固定组和双运动单元固定组，A1型组分别为35例和26例，A3型组分别为41例和39例。通过腰功能评分及脊髓神经功能2000分级标准评估临床结果；通过测量术前、术后1周、终末随访时骨折椎楔变指数、骨折节段矢状指数评估影像学结果。终末评估时间设为术后18个月。结果141例患者均得到随访。单运动单元固定组平均出血量与手术时间均明显少于双运动单元固定组，差异有统计学意义。两种术式临床疗效无明显差异。A1型组，单运动单元固定组与双运动单元固定组椎体楔变矫正指数与终末随访矫正丢失率差异有统计学意义，前者优于后者。A3型组，两组差异均无统计学意义，但前者失败率大于后者，差异有统计学意义。结论单运动单元椎弓根钉一棒系统内固定治疗部分A1及A3型胸腰椎骨折，可取得与双运动单元固定相近甚至更佳的疗效，且有出血少、用时短等优点；对于A3．2型胸腰椎骨折，因其失败率较高须严格掌握适应证。

Objective To investigate the feasibility of mono-segment pedicle instrumentation （MSPI） in management of thoraeolumbar fracture （AO classification, A1 and A3） by being compared with short-seg- ment（two-segment） pedicle instrumentation（SSPI）. Methods Overall 141 patients with tape A1 or A3 thora- columbar fractures, aged from 20 to 60 years （average, 40.5 years）, were enrolled in this prospective study. According to a simple randomized method, 35 patients with type A1 fracture and 41 patients with type A3 fracture were treated with MSPI, while 26 with type A1 fracture and 39 with type A3 fracture were treated with SSPI. Low back outcome score （LBOS） and ASIA2000 were used to evaluate clinical outcome. Eigh- teenth month postoperatively was assigned as the last follow up period. Wedge index （WI） and sagittal index （SI） of the affected vertebrae on radiography were measured and compared preoperatively, one week postop- eratively and at the final follow-up. Results All patients were followed up successfully. The blood loss and duration of operation of MSPI group were significantly less than that of SSPI group, respectively. However, there were no significant differences of clinical outcome between two groups. For type AI fracture, correction rate and correction loss of WI in MSPI group were better than those in SSPI group. For type A3 fracture, there were no significant differences of correction rate and correction loss of WI and SI between MSPI group and SSPI group; however, the failure rate of MSPI group was significantly higher than that of SSPI group. Conclusion For type A1 and partial type A3 thoracolumbar fractures, MSPI can provide the same or better fixation with less blood loss and operative duration than SSPI. Since MSPI for type A3.2 thoracolumbar frac- ture has a higher failure rate, the surgical indication should be strictly controlled.