Department of Radiology, North Cumbria University Hospitals NHS Trust, Carlisle, UK.
Skeletal Radiol. 2013 Feb;42(2):249-53. doi: 10.1007/s00256-012-1451-0. Epub 2012 Jun 9.
To investigate the value of post-traumatic pronator quadratus (PQ) fat pad sign as a reliable predictor of subtle wrist fractures.
This was a prospective study of 68 patients undergoing X-ray for traumatic wrist injuries and subsequent MRI. The reliability of a positive PQ fat pad sign on X-ray, defined as either raised, interrupted or obliterated, was evaluated in detection of subtle wrist fractures.
Out of 68 patients, 28 had a positive PQ sign without any obvious bony injuries on plain radiographs; of these, the PQ fat pad was obliterated in 11, disrupted in 12, and raised in five cases. Fractures defined as cortical interruption or trabecular fractures were revealed in 13/28 (46 %) patients with a positive PQ sign but only in 7/40 (18 %) patients with a negative sign. With regards to different types of abnormal PQ fat planes, fractures were present in 7/12 patients with a disrupted plane (58 %), 6/11 patients with an obliterated plane (54 %), and none of the patients with a raised plane. The overall sensitivity and specificity of a positive PQ sign in the prediction of occult wrist fractures were 65 and 69 %, respectively.
Our findings indicate that a positive pronator quadratus (PQ) fat pad sign is not a reliable predictor of subtle fractures of the wrist, although we believe that it is a useful radiographic sign in justifying MRI for further clarification of possible joint abnormalities including occult fracture and cortex interruption.
探究创伤后旋前方肌脂肪垫征（PQ 脂肪垫征）作为一种可靠的手腕隐匿性骨折预测指标的价值。
本研究为前瞻性研究，纳入了 68 例行 X 线检查的外伤性手腕损伤患者，并对其进行了后续 MRI 检查。评估 X 线上阳性 PQ 脂肪垫征（表现为抬高、中断或消失）在检测手腕隐匿性骨折中的可靠性。
68 例患者中，28 例 X 线平片未见明显骨损伤但出现阳性 PQ 征；其中，11 例 PQ 脂肪垫消失，12 例中断，5 例抬高。在出现阳性 PQ 征的 28 例患者中，有 13 例（46%）存在骨折（定义为皮质中断或小梁骨折），而在出现阴性 PQ 征的 40 例患者中，仅有 7 例（18%）存在骨折。对于不同类型异常 PQ 脂肪垫平面，中断平面的 12 例患者中有 7 例（58%）存在骨折，消失平面的 11 例患者中有 6 例（54%）存在骨折，而抬高平面的患者中无一例存在骨折。阳性 PQ 征预测隐匿性手腕骨折的总体敏感性和特异性分别为 65%和 69%。
我们的研究结果表明，阳性 PQ 脂肪垫征并不能可靠预测手腕隐匿性骨折，尽管我们认为该征是一种有用的影像学表现，可提示行 MRI 检查以进一步明确可能存在的关节异常，包括隐匿性骨折和皮质中断。
