In Advanced Kienbock Disease, SCA Improves Grip Strength at the Expense of Wrist ROM
The results of this study will allow hand surgeons to appropriately counsel patients and guide expectations when a scaphocapitate limited wrist fusion is being considered.
Anthony Sapienza, MD
Peter C. Rhee, DO, MS, Ines C. Lin, MD, Steven L. Moran, MD, Allen T. Bishop, MD, Alexander Y. Shin, MD. Scaphocapitate a rthrodesis for Kienböck disease. J Hand Surg Am. 2015; 40(4):745-751.
The authors report on outcome measures from a retrospective review of 27 patients with at least 1 year of clinical follow-up who underwent a scaphocapitate arthrodesis (SCA) for the treatment of advanced stages of Kienböck disease (stages III-IV). Outcome measures included:
- Preoperative and postoperative pain
- Range of motion
- Grip strength
- Additional surgery
- Radiographic changes
- Modified Mayo Wrist and Lichtman Outcome scores
Twenty-seven patients (17 males, 10 females) with a mean age of 41 years (range, 15–66 years) at the time of SCA were included in the study. The mean follow-up period was 60 months (range, 12 months–16 years).
Union was achieved in all 27 patients. Significant loss of mean motion from preoperative to postoperative was noted, with a decrease in flexion (43%), extension (54%), radial deviation (55%), and ulnar deviation (55%) compared with the unaffected side. Grip strength significantly improved after SCA (151% of preoperative measurement), but still had residual deficits compared with the contralateral wrist (64%).
The authors noted persistent pain in 19% (n=5) of patients, of whom 3 were successfully treated with an additional surgical procedure. Complex regional pain syndrome occurred in 14% (n=2) of patients. Modified Mayo Wrist scores were mostly fair to poor. Lichtman scores were satisfactory in 32% (n = 7) of patients, yet 74% of patients returned to regular employment.
Progressive radiographic carpal collapse and ulnar translocation of the carpus occurred, particularly in patients who had lunate excisions. The authors noted progression of degenerative changes for 11 patients, 2 of whom subsequently underwent total wrist arthrodesis.
SCA in patients with advanced stages of Kienböck disease resulted in improved grip strength with correction of carpal alignment at the expense of decreased wrist range of motion. Although radiographic carpal collapse and ulnar translocation occurred, patients were not symptomatic in the medium-term follow-up.
Kienböck disease typically presents with pain, loss of motion, and decreased strength due to the loss of vascularity to the lunate and its predictable pattern of lunate fragmentation, carpal instability, and carpal collapse.
Management of Kienböck disease is guided by the stage of the disease and ranges from immobilization to a variety of surgical options that include:
- Off-loading the lunate
- Joint leveling
- Lunate revascularization
- Salvage procedures
Limited wrist arthrodesis such as SCA can offer a motion-sparing salvage option in patients with a fractured lunate, if the cartilage shell of the lunate is not intact, or when chondral loss at the capitate head would contraindicate proximal row carpectomy.
The purpose of SCA is to off-load the lunate (if salvaged) and correct and/or preserve carpal height and scaphoid alignment. Theoretically, SCA provides a load-bearing column through which forces can be transmitted from the hand to the distal radius while bypassing the lunate.
Fusing the scaphoid to the capitate significantly limits any motion at the midcarpal joint and can result in increased shear stress at the radiocarpal joint, thus accelerating the development of degenerative changes. Potential complications after SCA include persistent wrist pain, complex regional pain syndrome, and progression of degeneration in the radioscaphoid and/or midcarpal joints.
The ideal treatment for each of the various stages of Kienböck disease remains elusive. The results of this study will allow hand surgeons to appropriately counsel patients and guide expectations when a scaphocapitate limited wrist fusion is being considered as a surgical salvage option that can still preserve some wrist motion.
Anthony Sapienza, MD, is an Assistant Professor of Orthopaedic Surgery, Division of Hand Surgery, Department of Orthopaedic Surgery, NYU Langone Medical Center – Hospital for Joint Diseases, and Co-Chief of Hand Surgery at Bellevue Hospital, New York, New York.