External fixation of distal radius fractures usually involves the use of a bridging fixator. However, immobilisation of the wrist can be associated with various complications and therefore dynamic external fixators were developed to allow wrist mobilisation with the fixator in place. But dynamic fixators themselves are not without complications and more recently interest has been rekindled in non-bridging external fixators (otherwise called metaphyseal or radial-radial fixators).

Following a pilot study using a non-bridging external fixator (Delta frame) in the treatment of intra-articular distal radius fractures, our aim in this study was to compare the functional and radiological outcome of the Delta frame and a standard wrist-bridging static external fixator in the treatment of such fractures. Sixty patients with intra-articular distal radius fractures were randomly allocated to receive either a static bridging Hoffman external fixator or a non-bridging Delta frame. All patients had the fixator removed at six weeks. Clinical and radiographic assessment was performed regularly up to a maximum of twelve months with the clinical results being expressed in terms of range of movement, pain, grip strength and ability to perform certain activities of daily living. Radiological assessment was performed by an independent radiologist. Mean follow-up was ten months.

The only sustained significant difference in function was a greater range of flexion in the Hoffman group. No significant difference could be detected between the two groups in terms of the radiological outcome. Complications included pin-site infection, paraesthesia, extensor pollicis longus tendon rupture and chronic regional pain syndrome. Three patients underwent further surgery. We did not demonstrate any advantage in the use of a non-bridging fixator in the treatment of intra-articular distal radius fractures.

The concept of bipolar hemiarthroplasty has been described in the hip for over twenty years, its role being to decrease acetabular wear. Shoulder bipolar hemiarthroplasty is a more recent concept. The purpose of this study was to determine if the prostheses acted as a bipolar device, moving primarily at the inner metal on polyethylene bearing as intended or as a unipolar hemiarthroplasty moving at the outer metal on cartilage surface.

Eleven bipolar shoulder hemiarthroplasties with a minimum follow up of twenty two months were examined fluoroscopically. The proportion of arm abduction occurring in the scapulothoracic plane as well as that between the two components of the bipolar hemiarthroplasty was assessed and compared to that of normal patients and those with total shoulder replacements, previously reported in the literature.

The results of this study show that the majority of movement occurring in active arm abduction occurred in the scapulothoracic plane and that the bipolar hemiarthroplasty acted predominantly as a unipolar device.