Volar, Splitting, and Collapsed Type of Die-Punch Fracture Treated by Volar Locking Plate (VLP): A Retrospective Study

Abstract

Objective: To compare the results of different types of die-punch fractures treated by volar locking plate (VLP).

Methods: Between January 2013 and February 2018, a total of 71 patients with die-punch fracture of distal radius were treated by VLP and their medical records were retrospectively reviewed. Of them, 18 were classified as volar type, 24 as splitting type, and 28 as collapsed type of fracture, based on the preoperative radiographs and CT scans. The minimum follow-up period was 12 months. Radiological parameters, wrist function, range of motion (ROM), and complications were evaluated and compared. Pearson chi-square test was used to assess the difference of gender distribution, injury side, dominance, mechanism, type and classification of fracture, and postoperative complications, when necessary (P < 0.05), followed by pairwise comparisons using partitions of chi-square test. Two-tailed P value <0.05 was considered as statistically significant. For pairwise comparisons, adjustment of statistical level as P < 0.017 (0.05/3) was used. SPSS 21.0 was used to perform all the analyses.

Results: The mean follow-up time was 14.5 months, and at the mean of postoperative 8 weeks all patients obtained bony union, without delayed or non-union. The grip strength was 26.6 ± 7.9 kg for patients in volar fracture group, 27.0 ± 9.4 kg in splitting group, and 26.2 ± 9.4 kg in collapsed group, without significant difference (P = 0.628).The disabilities of the arm, shoulder, and hand (DASH) (9.2 ± 10.0 for volar group, 8.8 ± 7.9 for splitting group, and 10.6 ± 8.7 for collapsed group) or Gartland-Werley score (5.1 ± 2.8 for volar group, 4.8 ± 3.2 for splitting group, and 6.4 ± 2.7 for collapsed group) either did not differ among the three groups (all P > 0.05). There was a poorer ROM in the group of collapsed fractures, but the difference was non-significant for any parameter (P > 0.05). As for radiographic parameters, we did not find any significant difference for volar tilt, radial inclination, radial height, and ulnar variance (all P > 0.05), except for articular step-off (P < 0.001). Pairwise comparisons showed a significantly greater step-off (1.2 mm vs 0.4 mm, 0.5 mm) and higher rate of total complications in group of collapsed fracture (39.3%), compared to either volar (10.5%) or splitting type (12.5%).

Conclusions: The collapsed type of die-punch fracture posed a greater articular step-off and a higher rate of complications, especially secondary wrist osteoarthritis, which deserved more attention in clinical treatment.

Keywords: Articular step-off; Collapse type; Die-punch fracture; Splitting type; Volar type.