A prospective randomised study was undertaken of patients with displaced Colles’ type distal radial fractures. Group 1 underwent bridging external fixation with a Pennig device; group 2 underwent manipulation and plaster immobilisation. All patients were initially treated for 6 weeks and reviewed regularly for 12 months.

At a mean of 7.8 years 86 fractures were available for review (36 treated by fixator and 50 treated in plaster). They were assessed to determine the anatomical and functional outcome of their wrist and also the incidence of post-traumatic degenerative change.

The patients had standard anteroposterior and lateral radiographs taken, to allow standard measurements to be made. The degree of arthritic change was also documented. An independent physiotherapist carried out a functional assessment, consisting of range of movement and grip strength in both wrists.

A Gartland and Werley demerit score was calculated, 94% of patients in each group had an excellent or good outcome. Patient satisfaction was comparable, 94% in the fixator and 92% in the plaster group were entirely satisfied.

Although a significant difference was found in terms of radial shortening between the groups, favouring the fixator group (p< 0.05), shortening of > 2mm did not adversely effect the functional outcome. However bridging external fixation did not improve the dorsal angulation in this study. No other radiological or functional parameter showed a statistical difference between the groups.

One patient in this series developed symptomatic post-traumatic arthritis. Grade 1 radiological signs (Knirk & Jupiter) occurred in 25% of patients but only half of these had sustained intra-articular fractures.

In conclusion: no overall long term benefit has been found to treating Colles’ type distal radial fractures with bridging external fixator as compared to plaster immobilisation.