What Role Do Plain Radiographs Have in Assessing the Skeletally Immature Acromioclavicular Joint?

Abstract

Background Because of incomplete ossification of the coracoid process and acromion, acromioclavicular joint configuration in the skeletally immature patient differs from that of adults. Although comparison to radiographic standards for this joint is critical in the evaluation of acromioclavicular joint injuries, these standards are not well defined for children or adolescents. Questions/purposes We therefore sought to determine (1) the reliability of numerous radiographic measurements of the skeletally immature acromioclavicular joint, including the vertical and shortest coracoclavicular interval, and the acromioclavicular joint offset; (2) the timing of ossification of the acromion and coracoid in males and females; and (3) the differences in the values of these radiographic measurements based on age and sex. Methods This study was based on a total of 485 subjects, 8 to 18 years old, who underwent conventional AP view radiographs of both shoulders. The 485 subjects were included to assess normal configuration around the acromioclavicular joint and 466 of these subjects were evaluated for comparison between both sides. The vertical and shortest coracoclavicular interval, coracoclavicular clavicle width ratio, acromioclavicular joint offset, and difference of the coracoclavicular interval of both sides were measured. A reliability test was conducted before obtaining the main measurements. The relationship of measurements with sex, age, and stage of ossification was evaluated.Results The vertical and shortest coracoclavicular interval showed excellent reliability (intraclass correlation coefficient ([ICC], 0.918 and 0.934). The acromioclavicular joint offset showed low reliability (ICC, 0.543). The ossification centers of the acromion and the coracoid processes appeared and fused earlier in females than in males. The vertical coracoclavicular interval, which was not affected by partial ossification of the coracoid process, was less than 11 mm in the 90% quantile of total subjects in males and 10 mm in the 90% quantile in females. The difference of the vertical coracoclavicular interval of both sides was less than 50% in 436 of 466 (93.4%) patients.

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“…Male and female right ACJ has a correlation coefficient of -.785 and -.839 respectively while the male and female left ACJ has a correlation coefficient of -.797 and -.780 respectively. This finding is in line with several studies [7,19,20] which show a negative correlation between acromioclavicular joint space with age. These could be attributed to degenerative changes occurring as age increases.…”

“…Guillotin et al [24] noted that the incidence of radiological changes in the ACJ increases with age and that degenerative change accounts for 68% in patients below 30 years and 93% in patients above 30 years. Also, similar works [7,19,20,25] on the AC joint space diameter have found a decrease in the joint space with age in both males and females. The right and left ACJ space diameters in males were compared to that of the females and the results show a statistically significant difference with male ACJ being higher than the female (p = 0.024).…”

Radiographic Determination of Normal Range Values of Acromioclavicular Joint Space in Nigerian Population

“…Petersson and Redlund [19] also stated that widening of the AC joint space greater than 7mm in males and 6 mm in the female when compared to the normal value is pathological irrespective of the age of the patient. Accurate diagnosis of these pathologies of the acromioclavicular joint space depends largely on the knowledge of the population-specific normal reference range values as Lee et al [20] noted potential differences in average skeletal size between Asian and Western populations. They further opined that the absolute measurement of acromioclavicular joint space of the Asian population will differ from the values in the Western population.…”

Reliability of the ISAKOS Modification to Subclassify Rockwood Type III Acromioclavicular Joint Injuries

“…Similar to our results, the CCD measurement was reproducible and has shown strong concordance for inter-and intraobserver reliability in previous reports. 23,36 On the other hand, a correct and reliable diagnosis of horizontal plane instability is critical to distinguish stable from unstable injuries and establish rational treatment recommendations. Unfortunately, this differentiation is difficult to make in most cases, as the diagnosis of a predominantly 3-dimensional dynamic injury is made using a static imaging modality.…”