gms | German Medical Science

Objectives/Interrogation: Scaphoidectomy, combined with four-corner fusion, is commonly used to treat scapholunate and scaphoid nonunion advanced collapse (SLAC; SNAC) wrists. We evaluated the effectiveness of this technique using the Medartis Aptus 4CF locking plate in a retrospective study followed up for at least two years.

Methods: We included all patients with SNAC or SLAC wrists grade 2 or 3 who underwent scaphoid excision with four-corner fusion using the Aptus 4CF dorsal locking plate (Medartis® Four-corner fusion dorsal locking plate, Medartis AG, Basel, Switzerland) between January 2010 and February 2015. A total of 50 patients (42 men, 8 women) were included and were followed up for at least two years.

All operations were performed in our department by the same surgical team, and all patients underwent clinical and radiologic assessments by an independent observer

Results and Conclusions: Fifty patients (median age 58 years; range 23-80 years) underwent surgery. Median pain scores decreased from 9 (range 6 10) to 3 (range 0 8). Postoperative wrist motion was statistically significantly improved, both in flexion and extension (medians, 30° vs. 60° in flexion; 20° vs. 40° in extension). Similarly, ulnar and radial deviation improved from 20° to 30° and from 10° to 30°, respectively. Median grip strength improved significantly after surgery (80% vs. 57% of contralateral grip strength at last follow-up). Nonunion occurred in 7/51 (13.7%) wrists, and conversion to total wrist fusion was necessary in 5/51 (9.8%) wrists. We achieved successful fusion in 44/51 (86.3%) cases. Scaphoidectomy with four-corner fusion using the Aptus 4CF locking plate resulted in successful joint fusion in 86.3% of wrists and led to statistically significant reduction of pain and ROM as well as statistically significant improvement of grip strength. However, we believe that regardless of the type of material used, it is crucial for successful joint fusion to respect all surgical steps, namely complete removal of the cartilage and subchondral bone, proper positioning of the implant, use of a healthy bone grafts from the distal radius, and compliance with a an immobilization period of 4 to 6 weeks.