The Distal Clavicle Morphology

Abstract

| ABSTRACT Background: To our knowledge, no previous studies have been conducted to comprehensively examine the morphology of the distal clavicle. The purpose of this study was to examine the distal clavicle morphology by assessing the dimensions and the angles of the distal clavicle in relation to the design of a potential distal clavicle prosthesis. Methods: Twenty cadaver clavicles were examined. The dimensions of the distal clavicular joint facet were directly assessed using a digital micrometer. Other angles and dimensions of the distal clavicle were assessed by taking measurements from the photographs of these clavicles taken from the anterior, the superior, and the inferior views. Radiographs were used to assess the cortices of the distal clavicle. Results: The average dimension of the distal clavicle joint facet was 14.7 mm (95% confidence interval [CI], 13.2Y16.1 mm) by 10.0 mm (95% CI, 9.2Y10.9 mm). The average dimension of the clavicle at 2 cm from its distal joint facet was 19.5 mm (95% CI, 17.6Y21.4 mm) by 10.0 mm (95% CI, 9.0Y11.0 mm). The average distal curvature length was 38.7 mm (95% CI, 36.7Y40.6 mm). The average distal curvature angle was 81 degrees (95% CI, 75Y87 degrees). The average normal length was 34.2 mm (95% CI, 30.8Y37.5 mm). The lateral tilting angle was measured to have an average value of 81 degrees (95% CI, 78Y84 degrees). The cortices of the distal clavicle were deficient. Conclusions: The results of this study suggest that the dimension of the distal clavicle joint facet, 13.2 to 16.1 mm (95% CI) by 9.2 to 10.9 mm (95% CI), would provide reference values for the size of the head piece of a distal clavicle prosthesis. The distal curvature length of 36.7 to 40.6 mm (95% CI) and the normal length of 30.8 to 37.5 mm (95% CI) would provide reference values for the length of the stem part of the prosthesis. The lateral tilting angle 78 to 84 degrees (95% CI) should be met to reproduce the natural distal clavicle anatomy.

Morphology of Distal Third of Clavicle in Dry Bone and Correlation With Length: A Cross-Sectional Study.

“…Hence, the distal end of the clavicle may not hold the prosthesis well due to thinness. The cortex is visible at the mean distance of 12.3mm anteriorly-posteriorly & 7.8mm superiorlyinferiorly from the distal end facet [5]. In this study, the mean thickness from superior surface to inferior surface(S/I) of the lateral edge of the clavicle was 10.5±2.24mm&10±00mm (p value not significant) on the right & left side clavicle.…”

“…Approximately 25% of distal clavicle fractures are unstable [4]. The cortex of the distal end of the clavicle is very thin & reaches full thickness earlier than the sternal end [5]. The support of the trapezoid & conoid ligaments of the acromioclavicular joint is an important factor for the stability of the fracture repair of the distal end of the clavicle [6].…”