Intraobserver and Interobserver Reliability of the Measurement of the Coracoclavicular Distance in Acromioclaviclular Dislocation and A new Technique of Measurement

ABSTRACT

Background: The diagnosis of acromioclavicular (AC) joint injury depends upon primary physical and radiological examinations. Simultaneous views of both AC joints are obtained and measurements compared between injured and uninjured sides. Most commonly, the severity of injury is determined by the relative differences between the widths of the AC joint space, the coracoclavicular (CC) distance, and degree of elevation of the clavicle above the acromion. These parameters are usually used to decide on surgical or conservative treatments. The measurement’s variation can change the treatment options.Objectives: To evaluate the reliability of the current method for measuring the CC distance and introducing the new method of measuring the width of CC distance by using a Mose’s template.Design: Descriptive studySetting: Department of Orthopedic, faculty of medicine, Khon Kaen University.Subjects: The anteroposterior radiograph of both acromioclavicular joints with Zanza technique were used in this study. Twenty radiographs were selected based on the quality of the radiograph. There were 15 male and female patients. The average age of the patients was 25±6 years old (range 20-48). Thirteen patients had right and seven had left AC joint injuries. Two observers were included in this study to evaluate the reliability of the current and new methods.Results: There were thirty-two of 40 pairs (32/40, 80 %, 95% confidence interval 67.61%-92.39%) of measurement by two observers (interobserver reliability) using Mose’s template had the  same results. However, the current technique used by two observers had the same results only three of 40 pairs (3/40, 7.5%,95% confidence interval 7.2%-7.8%) of measurements. The intraobserver reliability, for the Mose’s template of the observer I and II, there were 8 of 10 (8/10, 80%, 95% confidence interval 30%-90%) and 6 of 10 pairs (6/10, 60%, 95% confidence interval 30%-90%) of measurements had the same results respectively. For the current technique, however, there were only two of 10 pairs(2/10,20%,95% confidence interval 0-45%) and one of 10 pairs (1/10, 10%,95% confidence interval 1%-29%) of measurements of the observer I and II had the same results respectively.Conclusion: The Mose template technique is a more reliable method of measurement the CC distance in the AC joint injury.