Department of Orthopaedic and Trauma Surgery, Edinburgh Royal Infirmary, Little France, Edinburgh EH16 4SU, United Kingdom.
Department of Orthopaedic and Trauma Surgery, Edinburgh Royal Infirmary, Little France, Edinburgh EH16 4SU, United Kingdom.
Injury. 2019 Dec;50(12):2196-2202. doi: 10.1016/j.injury.2019.09.027. Epub 2019 Sep 20.
There is currently a lack of agreed criteria for sonographic assessment of callus and reliability between reviewers. The primary aim of this study was to determine criteria and reviewer agreement for sonographic bridging callus (SBC) on ultrasound. The secondary aim was to analyse the use of ultrasound to detect bridging callus in a prospective cohort of patients with a conservatively managed clavicle fracture.
A prospective cohort of conservatively managed displaced midshaft clavicle fractures underwent ultrasound scanning at three-, six- and 12-weeks post-injury. The main outcome was nonunion confirmed at six months on CT scanning. Five patients with confirmed nonunion were compared against a control group of 15 patients with timely union at three months. The ultrasound scans were interpreted by two blinded reviewers to evaluate sonographic callus features with agreement determined by weighted kappa. A further validation study was undertaken by four blinded reviewers using the intraclass-correlation-coefficient (ICC) using the most clinically relevant findings of the pilot work.
At three weeks post-injury fibrocartilaginous material was present in 80% of patients (16/20). When detected this was associated with union (sensitivity 93%, specificity 60%, p = 0.03) with the inter-observer agreement rated 'fair' on kappa (0.44). At six weeks only 10% (2/20) of patients had bridging callus on radiograph but 60% (12/20) had sonographic bridging callus (SBC) and when present all united (sensitivity 80%, specificity 100%, p = 0.002). At 12 weeks, bridging callus was present on both radiographs and ultrasound in all patients that united (n = 15, sensitivity 100%, specificity 100%, p < 0.001). No patient that developed a nonunion at six months post-injury had SBC at any time point. At six-weeks the absence of SBC had a positive predictive value for nonunion of 63% of patients (5/8) and by 12 weeks it was 100% (5/5). The SBC detection rated 'very strong' for intra- (kappa 0.92) and inter-observer agreement (kappa 0.84). The ICC of SBC at six-weeks with four blinded reviewers was 0.82 (95% confidence interval 0.68-0.91).
This is the first study to establish time specific ultrasound fracture findings with a repeatable technique and assess the agreement between blinded reviewers.
目前，超声评估骨痂的标准尚未达成共识，且不同评估者之间的可靠性也存在差异。本研究的主要目的是确定超声下桥接骨痂（SBC）的标准和评估者间的一致性。次要目的是分析在保守治疗锁骨骨折的前瞻性队列中，超声检测桥接骨痂的应用。
前瞻性纳入 20 例接受保守治疗的锁骨中段移位骨折患者，在受伤后 3 周、6 周和 12 周时进行超声检查。主要结局是在 CT 扫描上确认 6 个月时的骨不连。将 5 例经 CT 扫描证实为骨不连的患者与 15 例在 3 个月时及时愈合的对照组患者进行比较。由两名盲法评估者对超声扫描进行解读，通过加权 Kappa 确定评估者间的一致性。通过采用最具临床相关性的初步研究发现，由 4 名盲法评估者进行了进一步的验证研究，采用组内相关系数（ICC）。
伤后 3 周时，80%（20 例中的 16 例）患者存在纤维软骨样物质。当检测到这种物质时，骨折就会愈合（敏感性 93%，特异性 60%，p=0.03），评估者间的一致性通过 Kappa 评估为“中等”（0.44）。6 周时，只有 10%（20 例中的 2 例）的患者在 X 线片上有桥接骨痂，但 60%（20 例中的 12 例）的患者有超声桥接骨痂（SBC），当存在 SBC 时，所有患者都愈合（敏感性 80%，特异性 100%，p=0.002）。12 周时，所有愈合的患者（n=15）在 X 线片和超声上都有桥接骨痂（敏感性 100%，特异性 100%，p<0.001）。6 个月后发生骨不连的患者无一例在任何时间点有 SBC。6 周时，SBC 缺失对骨不连的阳性预测值为 63%（8 例中的 5 例），12 周时为 100%（5 例中的 5 例）。SBC 的检测具有很强的观察者内（kappa 0.92）和观察者间（kappa 0.84）一致性。4 名盲法评估者对 6 周时 SBC 的 ICC 为 0.82（95%置信区间 0.68-0.91）。
这是第一项使用可重复技术建立特定时间点超声骨折表现，并评估盲法评估者间一致性的研究。
