It is intended here to discuss the correction of these deformities rather than the treatment of the conditions leading to prolapse and collapse. Most hand surgeons will agree that in this kind of surgery success and failure go hand in hand and that it is difficult to separate the two. The success of treatment, in our opinion, is determined by a number of factors which we have tried to summarise as follows: 1. Timing of correction. 2. Nature of correction. 3. Period of immobilisation. 4. Prevention of adhesion formation. 5. Effect of devascularisation.