Session IX - Upper Extremity

Sat., 10/12/13 Upper Extremity, PAPER #100, 2:49 pm OTA 2013

Upright Compared to Supine Radiographs of Clavicle Fractures: Does Patient Positioning Affect Displacement?

Jonathon D. Backus1; David J. Merriman, MD2; Michael J. Gardner, MD1;
Christopher M. McAndrew, MD1; William M. Ricci, MD1;
1Washington University in St. Louis, Department of Orthopedic Surgery,
St. Louis, Missouri, USA;
2Mercy Clinic, Springfield, Missouri, USA

Background/Purpose: Clavicle fracture displacement, as determined from plain radiographs, is an important criterion in treatment planning. Radiographs taken with the patient supine may yield different results compared to those taken with the patient upright. The null hypothesis was clavicle fracture displacement measured on supine radiographs would be similar to displacement measured on upright radiographs.

Methods: 43 patients (average age 47 ± 18 years, 31 male) with clavicle fractures (35 OTA 15B, and 8 OTA 15C) who had AP and 30° caudal clavicle radiographs taken in both supine and upright positions were studied. Using a picture archiving and communication system (PACS), vertical displacement and clavicle length were measured and compared between the supine and upright positions retrospectively. One resident and two fellowship-trained traumatologists classified the fractures and measured displacement and shortening. Data were aggregated and compared to ensure reliability with a two-way mixed interclass correlation coefficient (ICC).

Results: Vertical fracture displacement averaged 13.8 ± 11 mm in upright radiographs and 8.1 ± 8.1 mm in supine radiographs (t test, P <0.001), representing a 69% increase in fracture displacement with upright positioning. Injured clavicle length was 15.9 ± 2 cm in upright radiographs and 16.4 ± 1.8 cm in supine radiographs (t test, P <0.05), a 3% decrease. 15 of 43 patients (35%) had greater than 100% clavicle diameter displacement seen on upright, but not on supine, radiographs. The ICC was 0.82 (95% confidence interval [CI]: 0.7-0.9) for OTA fracture classification, 0.92 (95% CI: 0.86-0.95) for vertical displacement measurement, and 0.91 (95% CI: 0.81-0.95) for injured clavicle length, demonstrating very high agreement of fracture classification and measurement among evaluators.

Conclusion: Increased fracture displacement and shortening was observed in upright radiographs compared to supine radiographs when evaluating clavicle fractures. The null hypothesis was disproved. This suggests that upright radiographs may better estimate fracture energy and severity, and better predict the position at healing if nonoperative treatment is selected. Both upright and supine radiographs are recommended to accurately determine the extent of fracture motion. The addition of upright radiographs could have significant impact on operative indications for clavicle fixation.

Alphabetical Disclosure Listing

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.