Scapholunate (SL) dissociation is the commonest cause of carpal instability. The management of this condition is controversial and depends on the time elapsed since the injury. Good results have been reported by Palmer et al. (1978) from immobilization in plaster if the treatment was started within 4 weeks of the injury and if an anatomical reduction was maintained. Open reduction and internal fixation is preferred by most authors in acute injuries (Stanley and Trail, 1994). Lavernia et al. (1992) advocate use of supplementary dorsal capsulode- sis in such cases. For chronic cases (more than 6 weeks after injury) but before the onset of degenerative changes, ligament reconstruction (Dobyns et al., 1975), dorsal capsulodesis (Blatt 1987) and intercarpal fusion (Watson et al., 1986) have all been proposed. SL instability without radiocarpal arthritis has been classified into Dynamic I, Dynamic II and Static insta- bility (Stanley and Saffar, 1994). The X-rays of the loaded and unloaded wrist are normal in Dynamic I instability but wrist arthroscopy shows a step-off between the scaphoid and the lunate. In the Dynamic II instability the radiograph of an unloaded wrist on PA view is normal but shows widening of the SL gap on loading. Arthroscopy shows a wide step-off between the scaphoid and lunate. In the static instability the SL gap may be wider than the triquetrolunate gap in an unloaded wrist. A lateral radiograph would always show the scaphoid to be in flexion (SL angle >60°). Arthro- scopy in such a case would be grossly abnormal and there is usually a communication between the radio- carpal and the midcarpal joint through which an arthro- scope may or may not pass. (Stanley and Saffar, 1994). The amount of scaphoid shortening and the ulnar translation of the scaphoid when the hand is moved from ulnar to radial deviation, i.e. the column/row (C/R) index varies in a normal population in a binomial distribution (with values varying from 0.5 to 1.0) (Craigen and Stanley, 1995). It has been suggested that this may influ- ence the predisposition to capsuloligamentous injuries of the wrist (Garcia-Elias et al., 1995) and also predict the success of some of the surgical procedures in the treat- ment of SL dissociation (Craigen and Stanley, 1995). In this prospective study we report our results of dor- sal capsulodesis for chronic SL dissociation without advanced degenerative changes. The influence of the C/R index on the eventual outcome has also been analysed. Patients with chronic SL dissociation with sta- tic and fixed DISI (dorsal intercalated segmental insta- bility) or advanced degenerative changes in the midcarpal or radiocarpal joints did not undergo dorsal capsulodesis in this series. PATIENTS AND METHODS In our unit all cases of chronic SL (>6 weeks after injury) dissociation are initially treated by intermittent splintage and modification of activity. This is followed by a period of occupational therapy. Surgery is advised if symptoms are unrelieved after a 2 to 3 month trial. During the period from January 1990 to December 1992, 52 patients underwent Blatt’s (1987) dorsal capsu- lodesis for chronic SL dissociation. Eight patients have been lost to follow-up. Of the remaining 44 patients, there were 20 women and 24 men. The average age at the time of injury was 29 years (range, 19–46 years). The average time from injury to surgery was 4 years and 10 months. Thirty-eight patients had a definite history of an acute injury and six had pain after repetitive use of the hand at work or after sports. The dominant hand was involved in 28 patients. The average length of follow-up was 22 months (range, 1–3 years). Each patient was assessed preoperatively and postoperatively and a detailed questionnaire was completed. All patients had preoperative clinical evidence of SL instability (including a positive scaphoid shift test). The severity of the pain was rated according to the visual analogue scale (VAS). The frequency of occurrence of the pain (constant or intermittent) and aggravating and relieving factors (heavy work, light work or at rest and the type of wrist movement causing the pain) were also noted. Additional 215 BLATT’S CAPSULODESIS FOR CHRONIC SCAPHOLUNATE DISSOCIATION S. C. DESHMUKH, P. GIVISSIS, D. BELLOSO, J. K. STANLEY and I.A. TRAIL From the Centre for Hand and Upper Limb Surgery, Wrightington Hospital, Wigan, UK We have reviewed prospectively 44 cases of chronic scapholunate dissociation treated by Blatt’s dorsal capsulodesis. The diagnosis was based on clinical and arthroscopic criteria. The minimum follow-up was 2 years. The results were analysed clinically and radiologically. Postoperatively statistically significant reductions in wrist movements and grip strengths were noted. Delay in surgery and presence of compensation claims were also statistically significant factors. Patients with a high column/row index had higher overall good and excellent results.The scapholunate gap, scapholunate angle, carpal height and the type of instability as diagnosed on arthroscopy and cineradiography did not affect the outcome significantly. The scapholunate gap, scapholunate angle and the carpal height did not change significantly after operation. Journal of Hand Surgery (British and European Volume, 1999) 24B: 2: 215–220