Lahham Shadi, Becker Brent, Chiem Alan, Joseph Linda M, Anderson Craig L, Wilson Sean P, Subeh Mohammad, Trinh Alex, Viquez Eric, Fox John C
University of California Irvine, Department of Emergency Medicine, Orange, California.
Wellspan York Hospital, Department of Emergency Medicine, York, Pennsylvania.
West J Emerg Med. 2016 May;17(3):377-82. doi: 10.5811/westjem.2016.2.29290. Epub 2016 Apr 26.
The goal of this study was to investigate the efficacy of diagnosing shoulder dislocation using a single-view, posterior approach point-of-care ultrasound (POCUS) performed by undergraduate research students, and to establish the range of measured distance that discriminates dislocated shoulder from normal.
We enrolled a prospective, convenience sample of adult patients presenting to the emergency department with acute shoulder pain following injury. Patients underwent ultrasonographic evaluation of possible shoulder dislocation comprising a single transverse view of the posterior shoulder and assessment of the relative positioning of the glenoid fossa and the humeral head. The sonographic measurement of the distance between these two anatomic structures was termed the Glenohumeral Separation Distance (GhSD). A positive GhSD represented a posterior position of the glenoid rim relative to the humeral head and a negative GhSD value represented an anterior position of the glenoid rim relative to the humeral head. We compared ultrasound (US) findings to conventional radiography to determine the optimum GhSD cutoff for the diagnosis of shoulder dislocation. Sensitivity, specificity, positive predictive value, and negative predictive value of the derived US method were calculated.
A total of 84 patients were enrolled and 19 (22.6%) demonstrated shoulder dislocation on conventional radiography, all of which were anterior. All confirmed dislocations had a negative measurement of the GhSD, while all patients with normal anatomic position had GhSD>0. This value represents an optimum GhSD cutoff of 0 for the diagnosis of (anterior) shoulder dislocation. This method demonstrated a sensitivity of 100% (95% CI [82.4-100]), specificity of 100% (95% CI [94.5-100]), positive predictive value of 100% (95% CI [82.4-100]), and negative predictive value of 100% (95% CI [94.5-100]).
Our study suggests that a single, posterior-approach POCUS can diagnose anterior shoulder dislocation, and that this method can be employed by novice ultrasonographers, such as non-medical trainees, after a brief educational session. Further validation studies are necessary to confirm these findings.
本研究的目的是调查本科医学生采用单视角、后路即时超声检查（POCUS）诊断肩关节脱位的有效性，并确定区分脱位肩关节与正常肩关节的测量距离范围。
我们纳入了一个前瞻性、便利样本，即因受伤后急性肩部疼痛到急诊科就诊的成年患者。患者接受了可能的肩关节脱位的超声评估，包括对肩部后方的单一横向视图以及对肩胛盂和肱骨头相对位置的评估。这两个解剖结构之间距离的超声测量值称为盂肱分离距离（GhSD）。GhSD为正值表示肩胛盂边缘相对于肱骨头位于后方，GhSD值为负值表示肩胛盂边缘相对于肱骨头位于前方。我们将超声（US）检查结果与传统X线摄影进行比较，以确定诊断肩关节脱位的最佳GhSD临界值。计算了所推导的超声方法的敏感性、特异性、阳性预测值和阴性预测值。
共纳入84例患者，其中19例（22.6%）在传统X线摄影中显示肩关节脱位，均为前脱位。所有确诊的脱位患者GhSD测量值均为阴性，而所有解剖位置正常的患者GhSD>0。该值代表诊断（前）肩关节脱位的最佳GhSD临界值为0。该方法的敏感性为100%（95%可信区间[82.4 - 100]），特异性为100%（95%可信区间[94.5 - 100]），阳性预测值为100%（95%可信区间[82.4 - 100]），阴性预测值为100%（95%可信区间[94.5 - 100]）。
我们的研究表明，单次后路POCUS可诊断前肩关节脱位，并且经过简短的培训课程后，非医学专业实习生等新手超声检查人员也可采用此方法。需要进一步的验证研究来证实这些发现。
