The authors are to be commended for candidly reporting their results from the largest series of patients who have undergone a dorsal capsulodesis for the treatment of symptomatic scapholunate instability. They found that dorsal capsulodesis does not provide long-term correction of carpal alignment and does not prevent the development of radiocarpal arthritis. These findings emphasise what other studies have previously shown, albeit with shorter follow-up.1,2 The authors suggest that despite these shortcomings, capsulodesis still has a role in our surgical armamentarium for the management of scapholunate instability.
Since its classic description by Linscheid and Dobyns in 1972, surgeons have had little clinical success with the long-term repair of the scapholunate ligament.3 At present, the two major techniques for the correction of scapholunate instability without significant radiocarpal arthritis include some form of tenodesis or capsulodesis procedure: both techniques attempt to tether the scaphoid in extension using either a portion of a tendon (tenodesis) or a portion of the dorsal wrist capsule (capsulodesis). While both techniques have been shown to prevent scaphoid flexion initially, neither technique has been shown to prevent the long term development of carpal collapse or radiocarpal arthritis.
There are some weaknesses in the present study, which are unavoidable due to its retrospective nature. These include the inability to provide the reader with pre-operative pain scores, DASH scores or Mayo wrist scores: thus it is difficult to assess if patients are genuinely improved after surgery. Neither are we provided with any of the data from the patient satisfaction questionnaires; this data would help the reader to determine if patients were truly satisfied with their wrist function. In this study, patients reported an on-going daily pain score of 4.8 out of 10 following surgery; by comparison, patients with longstanding scapholunate ligament injuries who were followed expectantly have been found to have resting wrist pain scores of 3.2 and 6.2 following activity, using a similar 10-point pain scale.4 Prospective randomized studies will be needed to determine whether surgery, of any kind, is beneficial to observation alone in this patient population.
In addition, the results of the study show that dorsal capsulodesis can produce a wide range of clinical outcomes: the patient’s postsurgical DASH scores ranged from 0 to 71, and Mayo wrist scores ranged from 0 (poor) to 90 (excellent). Our inability to provide a consistent outcome with this procedure may stem from our poor understanding of the natural history of untreated isolated ligament injuries of the scapholunate joint. A study by O’Meeghan and colleagues has shown us that patients with complete scapholunate dissociation do not progress to frank arthritis even after a mean seven years of follow-up.4 Yet after dorsal capsulodesis we see that the majority of patients develop signs of wrist arthritis within a similar period. Further prospective longitudinal outcome studies which examine the natural course of scapholunate ligament injury will need to be performed to determine if a subset of patients definitely benefit from surgical intervention, as suggested by studies examining carpal shape and contralateral wrist mechanics.5,6
Despite the shortcomings of dorsal capsulodesis, I agree with the authors’ conclusion that capsulodesis still has a role in the management of SL instability. However, before operating, the surgeon must present the patient with an honest assessment of the expected outcomes and educate the patient about what we know about the natural history of this ligament injury. In my own practice, I rely on the level of the patient’s pain and their inability to perform daily activities to steer me towards surgery. We do not treat asymptomatic patients with abnormal radiographs, or incidental findings of scapholunate instability.
At present no other type of surgical treatment has been shown to be statistically superior to dorsal capsulodesis.7 Thus, surgeons will have to determine which surgical technique to use based on comfort level and personal experience. New techniques which repair the volar and dorsal component of the ligament may have better outcomes. In addition, new biological solutions, such as tissue engineered ligaments, are looming on the horizon. The authors’ study emphasise the need for further research into scapholunate ligament repair and begs a new perspective to fix this old problem.
1.Deshmukh SC, Givissis P, Belloso D, Stanley JK, Trail IA. Blatt's capsulodesis for chronic scapholunate dissociation. J Hand Surg Br 1999;24:215-20.
2. Moran SL, Cooney WP, Berger RA, Strickland J. Capsulodesis for the treatment of chronic scapholunate instability. J Hand Surg Am 2005;30:16-23.
3. Linscheid RL, Dobyns JH, Beabout JW, Bryan RS. Traumatic instability of the wrist. Diagnosis, classification and pathomechanics. J Bone Joint Surg, 1972; 54A: 1612-32.
4. O'Meeghan CJ, Stuart W, Mamo V, Stanley JK, Trail IA. The natural history of an untreated isolated scapholunate interosseus ligament injury. J Hand Surg Br 2003;28:307-10.
5. Rhee PC, Moran SL, Shin AY. Association between lunate morphology and carpal collapse in cases of scapholunate dissociation. J Hand Surg Am. 2009; 34:1633-9.
6. Crisco JJ, Pike S, Hulsizer-Galvin DL, Akelman E, Weiss AP, Wolfe SW. Carpal bone postures and motions are abnormal in both wrists of patients with unilateral scapholunate interosseous ligament tears. J Hand Surg Am. 2003; 28: 926-37.
7. Moran SL, Ford KS, Wulf CA, Cooney WP. Outcomes of dorsal capsulodesis and tenodesis for treatment of scapholunate instability. J Hand Surg Am. 2006;31:1438-46.
Steven Moran, M.D. Chairman, Division of Plastic Surgery
Professor of Plastic Surgery
Professor of Orthopedics
Mayo Clinic, Rochester MN, USA