Introduction: Carpal scaphoid fractures can be treated non-operatively in a cast, but the duration of treatment can take up to 12 weeks, with non-union rates of 15%. The hypothesis of this study was: percutaneous fixation of acute scaphoid fractures results in better union rates, faster time to union, and better function.

Method: In a prospective study, 48 consecutive acute and subacute scaphoid fractures were treated with percutaneous Acutrak screws. These patients were compared to a case-matched control group treated non-operatively in a cast. Herbert-Fisher type A (‘crack’) and B4 (fracture-dislocations) fractures were excluded from the study. The implant is a cannulated headless titanium screw with conical design and continuous differential pitch for inter-fragmentary compression. The screw was introduced retrograde according to a technique devised by the senior author (MP). In addition to the standard postero-anterior and lateral views, prone and supine oblique views were used to achieve accurate screw placement.

Results: There were 16 B1 (oblique), 15 B2 (waist), four B3 (proximal pole) and nine B5 (comminuted) fractures in each group. The average operation time was 19 minutes. The union rate was 97.7% in the operated group, and 81.8% (36/44) in the non-operated group (p< 0.05). The average time to union was significantly quicker in the operated group (seven weeks compared to 12 weeks, p< 0.05). At 12 weeks post-treatment the range of motion as well as the pinch and grip strengths were better in the operated group. After 24 weeks the two groups had comparable functional results. The mean time taken return to work was 2.5 weeks with percutaneous fixation compared to 13 weeks with cast treatment (p< 0.05). The average delay with cast group in return to work was 10.8 weeks with an average loss of income of $8815. The overall cost to the community with the screw treatment was $7640 more with cast treatment. There were no complications in the operated group and seven non-unions in the cast group.

Conclusion: Primary percutaneous screw fixation of scaphoid fractures is reliable, fast, cost-efficient and reproducible. The learning curve is moderately steep. It results in improved union rates, decreased time to union, improved early function and early return to work. Prone and supine oblique views are invaluable in assessing accurate screw placement.