[Effectiveness analysis of maintaining the stability between the fourth and the fifth metacarple base during the treatment in the hamate-metacarpal joint injury].

Objective: To explore the effectiveness of maintaining the stability between the fourth and the fifth metacarple base during the treatment in the hamate-metacarpal joint injury.

Methods: Between September 2015 and June 2017, 13 cases of hamate-metacarpal joint injury were treated, including 12 males and 1 female, aged from 17 to 55 years (mean, 30.8 years). The injury causes included heavy boxing in 10 cases and falling in 3 cases. There were 2 cases of simple fourth metacarpal basal fracture, 1 basal fracture of the fourth metacarpal bone combined with intermetacarpal ligament fracture, 7 fractures of the fourth and fifth metacarpal base, 2 fourth metacarpal basal fractures combined with the fifth metacarpal basal fracture dislocation, and 1 base fracture of fourth and fifth metacarpal bone combined with hamate bone fracture. The time from injury to operation was 5-11 days (mean, 7.2 days). According to different damage degree and stability change between the fourth and the fifth metacarple base, a preliminary classification was made for different degrees of injury: 2 cases of type Ⅰ, 1 case of type Ⅱ, 7 cases of type Ⅲ, 2 cases of type Ⅳ, and 1 case of type Ⅴ. The patients were treated with corresponding internal fixation methods under the principle of stability recovery between the fourth and fifth metacarple base.

Results: All the incisions healed by first intention without infection or skin necrosis. All the 13 patients were followed up 6-18 months with an average of 9.4 months. All fractures healed clinically, and the healing time was 5.5-8.0 weeks with an average of 6.3 weeks. No complication such as plate breakage, fracture dislocation, fracture malunion, and bone nonunion occurred. Hand function was evaluated according to the total active motion (TAM) functional evaluation standard of hand surgery at 6 months after operation, and the results was excellent in 9 cases, good in 3 cases, and fair in 1 case, with an excellent and good rate of 92.3%.

Conclusion: Stability between the fourth and fifth metacarple base is of great significance to the classification and the treatment of the hamate-metacarpal joint injury.