Advanced osteoarthritis of the wrist or the distal articulation of the lunate with the capitate has traditionally been treated surgically by arthrodesis. In order to maintain movement, we performed proximal row carpectomy with capsular interposition arthroplasty as an alternative to arthrodesis in eight patients with advanced arthritis and retrospectively reviewed their clinical and radiographic outcomes after a mean follow-up of 41 months (13 to 53). The visual analogue scale (VAS) for pain at its worst and at rest, and the patient-rated wrist evaluation score improved significantly after surgery, whereas ranges of movement and grip strength were maintained at the pre-operative levels. Progression of arthritis in the radiocapitate joint was observed in three patients, but their outcomes were not significantly different from those without progression of arthritis.

Proximal row carpectomy with capsular interposition arthroplasty is a reasonable option for the treatment of patients with advanced arthritis of the wrist.

The zona conoidea comprises the area of the lateral trochlear ridge of the humerus. The purpose of this study is to reintroduce this term ‘zona conoidea’ to the discussion of the human elbow and to investigate its significance in the development of osteoarthritis of the elbow.

The upper extremities of 12 cadavers were prepared. With the forearm in neutral, pronation and supination, the distance between the bevel of the radial head and zona conoidea was inspected. A total of 12 healthy volunteers had a CT scan. The distance between the zona conoidea and the bevelled rim of the radial head was measured in these positions.

In the anatomical specimens, early osteo-arthritic changes were identified in the posteromedial bevelled rim of the radial head, and the corresponding zona conoidea in supination. Measurement in the CT study showed that in full supination, the distance between the bevel of the radial head and the zona conoidea was at a minimum.

This study suggests that the significant contact between the bevel of the radial head and the zona conoidea in supination is associated with the initiation of osteoarthritis of the elbow in this area.