AAHS Annual Meeting
Back to main AAHS site
Annual Meeting Home
Past & Future Meetings


Back to Annual Meeting Posters


Outcomes Assessment of Lunate Replacement Arthroplasty with Intrinsic Carpal Ligament Reconstruction
Mark Henry, MD
Hand and Wrist Center of Houston, Houston, TX

Introduction: With advanced Kienbock's disease, hyaline cartilage delamination or fragmentation of underlying bone render the lunate unsalvageable. Traditional treatments at this stage include proximal row carpectomy or wrist fusion (limited or total).
Materials and Methods: Thirteen consecutive Kienbock's patients with an unsalvageable lunate by CT scan chose to undergo lunate prosthetic replacement arthroplasty combined with reconstruction of the scapholunate and lunotriquetral interosseous ligaments using the flexor carpi radialis tendon. There were 7 females and 6 males, with a mean age of 40, prospectively enrolled in a cohort study. Pre-operative to post-operative measures were compared at a mean follow-up of 24.3 months from surgery with a paired, single-tailed, student's t-test using a p-value of 0.05 as statistically significant for: wrist flexion (degrees), wrist extension (degrees), absolute value grip strength (kg), grip strength vs. contralateral (percent), and Disabilities of Arm Shoulder and Hand (DASH) scores. Post-operative measurements were made from the final lateral radiograph of the capitolunate angle (degrees) and the scapholunate angle (degrees).
Results: Mean pre-operative / post-operative values (standard deviation) were: wrist flexion 29.2 (10.1) / 43.3 (18.8), wrist extension 24.2 (13.2) / 53.3 (14.9), absolute value grip strength 12.3 (4.9) / 31.5 (8.34), grip strength vs. contralateral 36.5 (8.4) / 85.2 (7.8), DASH scores 39.1 (14.2) / 7.7 (3.6). All differences were statistically significant; the highest p-value of 0.018 was for wrist flexion. The mean radiographic measurements (standard deviation) were capitolunate angle -5.1 (10.6) and scapholunate angle 48.3 (6.8), indicating a tendency for volar tilt of the lunate prosthesis. In one patient, achieving sagittal plane balance of the prosthesis proved impossible and the case was converted to a proximal row carpectomy. One patient had early migration of the stabilizing K-wire and required reoperation to replace it. There were no cases of wound infection, prosthetic dislocation, prosthetic erosion, carpal collapse, or avascular necrosis.
Conclusion: Although these subjective and objective results reflect substantial improvement, there remain recognizable deficiencies in both prosthetic design and surgical strategy that require further change before incorporating this treatment into the Kienbock's armamentarium. The coronal plane passages through the implant are too close to the axis of scapholunate rotation and too close to each other to effectively control sagittal plane balance of the prosthesis. Tendon graft routing for carpal stabilization needs to change from purely coronal to include a sagittal plane vector.


Back to Annual Meeting Posters

 

© 2018 American Association for Hand Surgery. Privacy Policy.