Hand and Upper Extremity Service, Department of Orthopaedic Surgery, Massachusetts General Hospital, 55 Fruit Street, Yawkey Center, Suite 2100, Boston, MA 02114. E-mail address for D. Ring:
Department of Orthopaedic Surgery, Boston Medical Center, Shapiro Ambulatory Care Center, 725 Albany Street, 4th floor, Suite 4B, Boston, MA 02118.
J Bone Joint Surg Am. 2014 Mar 5;96(5):403-7. doi: 10.2106/JBJS.M.00089.
Recent studies have identified specific subsets of diaphyseal humeral fractures for which functional bracing is less effective. The present study tested the hypothesis that a gap between fracture fragments may be a risk factor (after accounting for other potential risk factors) for fracture instability six weeks after functional bracing of humeral shaft fractures.
We retrospectively identified seventy-nine adult patients (forty-six men, thirty-three women; forty-two fractures on the right side, thirty-seven fractures on the left), each with an acute, closed, AO type-A2 (oblique, ≥30°) or type-A3 (transverse, <30°) mid-diaphyseal humeral shaft fracture treated nonoperatively at three different level-I trauma centers from June 2004 to August 2011. The gap between the fracture fragments was measured on the first radiographs made after the affected upper extremity was placed in a brace.
Sixty-three patients (80%) had documented healing of the fracture. Sixteen patients (20%) had motion at the fracture site and a persistent fracture line shown on radiographs six weeks or more after injury. In multivariable analysis, each millimeter of gap between the main fragments with the patient wearing the brace (odds ratio [OR] = 1.4, 95% confidence interval [CI] = 1.1 to 1.7), smoking (OR = 5.8, 95% CI = 1.4 to 25), and female sex (OR = 5.3, 95% CI = 1.2 to 23) increased the risk of fracture instability six weeks after injury (R2 = 0.38, area under the receiver operating characteristic [ROC] curve = 0.81).
The magnitude of the gap between the fracture fragments is an independent risk factor for fracture instability and the lack of a bridging callus six weeks after a diaphyseal humeral fracture.
最近的研究已经确定了一些特定的骨干肱骨骨折亚组，对于这些骨折，功能支具的效果较差。本研究检验了一个假设，即骨折碎片之间的间隙可能是功能支具固定后 6 周时肱骨干骨折不稳定的一个危险因素（在考虑其他潜在危险因素后）。
我们回顾性地确定了 79 名成年患者（46 名男性，33 名女性；右侧 42 例，左侧 37 例），每位患者均患有急性闭合性 A0 型-A2 （斜形，≥30°）或 A3 型（横形，<30°）肱骨干中段骨折，在 2004 年 6 月至 2011 年 8 月期间在 3 个不同的一级创伤中心接受非手术治疗。在将受影响的上肢置于支具中后拍摄的第一张 X 光片上测量骨折碎片之间的间隙。
63 名患者（80%）的骨折有记录的愈合。16 名患者（20%）在受伤后 6 周或更长时间内出现骨折部位活动和持续的骨折线。在多变量分析中，每个毫米的主碎片之间的间隙（OR = 1.4，95%置信区间 [CI] = 1.1 至 1.7），支具佩戴时的吸烟（OR = 5.8，95% CI = 1.4 至 25）和女性（OR = 5.3，95% CI = 1.2 至 23）均增加了受伤后 6 周时骨折不稳定的风险（R2 = 0.38，接受者操作特征 [ROC] 曲线下面积 = 0.81）。
骨折碎片之间的间隙大小是骨折不稳定的独立危险因素，也是骨干骨折 6 周后无桥接骨痂的独立危险因素。
