Anthropometric study of the proximal radius: does radial head implant fit in all cases?

The purpose of this study was to evaluate anthropometry of the radial head and neck and compare the results with radial head prosthesis in current use.

A total of 144 cases were analysed that underwent antero-posterior (AP) elbow radiographs in full supination and extension position between January 2013 and April 2013. Mean age was 54.3 years (range, 21-79). The distance between the articular surface and the radial tuberosity, the height of the radial head, the diameter of the radial head, and the width of the proximal radioulnar joint were measured. The specifications of 13 products from nine companies were compared with the parameters.

The mean distance between the articular surface and the radial tuberosity was 19.6 mm. Mean height, diameter, and width of the proximal radioulnar joint were 10.6, 22.0, and 8.9 mm, respectively. A violation of the distal biceps insertion will occur in up to 87.5 % of the cases when some of the bipolar implants were used. The height of some of the implant heads was larger than the height of head in our study. Although the height and diameter of the radial head were similar to those of previous reports, the distance between the articular surface of the head and radial tuberosity was different.

The anatomical parameters of the proximal radius of the cases, especially the distance between the articular surface of the head and the radial tuberosity, and the radial head implant specifications should be assessed when selecting a radial head implant.