Selected Outcomes of Thumb Replantation After Isolated Thumb Amputation Injury

Purpose The aim of this study was to assess thumb survival, pinch strength, grip strength, and need for secondary surgery in patients undergoing thumb replantation after isolated thumb amputation injury. Methods We conducted a retrospective review of 52 consecutive isolated thumb replantations performed over a 4.5-year period. Charts were reviewed for mechanism of injury, level of amputation, and surgical technique. Primary outcomes of interest included survival and secondary surgery (eg, tenolysis, neurolysis) rates. Functional outcome was assessed by pinch and grip strengths after a mean follow-up period of 10 months from the initial injury. Results The overall thumb survival rate was 92% (48 of 52). One hundred percent of Zone I injuries (13 of 13), 94% of zone II injuries (29 of 31), and 75% of zone III injuries (6 of 8) survived; overall survival was 94% in sharp injuries (32 of 34), 89% in avulsion injuries (8 of 9), and 89% in crush injuries (8 of 9). Secondary surgery was performed in 18 patients with increasing need across the 3 zones (0%, 42%, and 63%, respectively; p for trend = .002). Pinch and grip strengths of 17 patients after an average follow-up period of 10 months were significantly worse after crush/avulsion injuries (p = .007 and .07, respectively) and injuries requiring joint intervention (p = .004 and .02, respectively); grip strength was also found to be negatively associated with increasing zone of injury. Conclusions This retrospective study shows that a high rate of survival can be achieved after thumb replantation using current techniques. In addition, the need for secondary surgery is strongly related to zone of injury, with zone I injuries requiring the least amount of secondary surgery. Finally, pinch and grip strengths may be worse after crush or avulsion injuries and injuries requiring joint intervention. (J Hand Surg 2010;35A:1485-1490. (C) Copyright 2010 by the American Society for Surgery of the Hand. All rights reserved.)