Midcarpal Fusion with Excision of Scaphoid for Scapholunate Advanced Collapse(SLAC)

Abstract

Scapholunate advanced collapse (SLAG) deformity most often occurs with chronic rotary scaphoid instability resulting from scapholunate ligament tear and scaphoid fracture. Prior to 1984 when Dr. Kirk Watson reported his concept on SLAG wrist deformity, the most popular procedure for this pathological condition was scaphoid implant arthroplasty with or without midcarpal fusion. We have reviewed 15 cases of SLAG deformity during 1984 to 1993, which were treated with scaphoid excision and midcarpal fusion. Among them, scaphoid implants made of silicone were inserted in 4 cases. Scaphoid implant arthroplasty without carpal fusion was excluded. The mean period of follow-up was 8.8 years and the mean age of patients was 47.5 years. Males and right wrists were predominant. Wrist motion was limited to 55.6% of the opposite normal wrist and grip power was average 71% of the opposite normal hand. Overall, 8 patients had no pain and 7 patients had mild pain. The grade of pain was minimal. (Rating system: no pain-0, mild-1, moderate-2, severe-3). However, all of the 4 cases of limited carpal fusion with a scaphoid implant developed silicone paniculate induced synovitis and pain. The procedure appears to be effective in maintaining function of the hand with minimal pain up to 5.8 years. However, silicone scaphoid implant appears to be not necessary and is not recommended for this pathological condition with a limited carpal fusion.