Abstract：
Ulnar variance is an important radiological parameter for good functional outcome after distal radius fracture osteosynthesis. Secondary loss of reduction due to radial shortening is a common complication after volar locking plate fixation. Some authors recommend beginning by placing the most ulnar epiphyseal screw, ensuring that it is positioned as close as possible to the distal radioulnar and radiocarpal joints. The hypothesis of our study was that the positioning of the ulnar epiphyseal screw relative to the distal radioulnar and radiocarpal joints influences the maintenance of reduction during follow-up. 190 distal radius fractures were treated with volar locking plate fixation and divided into two cohorts: cohort A with <2 mm and cohort B with ≥2 mm loss of ulnar variance. Minimum follow-up was 45 days. The positioning of the most ulnar epiphyseal screw was evaluated using a single variable, the ulno-distal index. Means were compared using t-tests and proportions using chi-squared tests. The alpha risk was set at 5%. The intra- and inter-observer reliability of the ulno-distal index measurement were assessed. Mean ulno-distal index was significantly lower in cohort A at 11.28 mm, compared to 13.33 mm in cohort B; p < 0.0001. Ulno-distal index <12 mm was a significant protective factor: p < 0.0001 and relative risk 0.558. No other intrinsic or extrinsic factors of secondary loss of reduction significantly influenced the risk of ulnar variance alteration. The study confirmed the hypothesis that, in distal radius fracture treated with volar locking plate fixation, the closer the ulnar epiphyseal screw to the distal radioulnar joint and radiocarpal joint, the lower the risk of ulnar variance alteration.
摘要：
尺骨变异是桡骨远端骨折接骨术后良好功能结局的重要放射学参数。掌侧锁定钢板固定后，由于radial骨缩短而导致的继发性减少是常见的并发症。一些作者建议首先放置最尺骨骨phy螺钉，确保它的位置尽可能靠近下尺尺远端和桡骨关节。我们研究的假设是，尺骨骨螺钉相对于尺尺尺远端和ri腕关节的定位会影响随访期间复位的维持。190例桡骨远端骨折采用掌侧锁定钢板内固定术治疗，分为两组：A组<2mm，B组尺骨方差丢失≥2mm。最短随访时间为45天。使用单个变量评估最尺骨骨phy螺钉的位置，ulno远端指数。使用t检验比较平均值，使用卡方检验比较比例。阿尔法风险设定为5%。评估了ulno远端指数测量的观察者内部和观察者之间的可靠性。队列A的平均ulno远端指数在11.28mm处显着降低，与队列B中的13.33mm相比；p<0.0001。Ulno远端指数<12mm是一个重要的保护因素：p<0.0001，相对危险度为0.558。没有其他次要减少损失的内在或外在因素显着影响尺骨方差改变的风险。这项研究证实了这一假设，掌侧锁定钢板内固定术治疗桡骨远端骨折,尺骨骨phy螺钉越靠近尺尺远端关节和桡骨关节，尺骨方差改变的风险越低。
