gms | German Medical Science

Objectives/Interrogation: The volar-displaced distal radius fractures was considered to be easy to treat before. Harness reported that there were 7 cases of palmar subluxation after volar plating for distal radius fractures. He described all cases were B3 type of AO-classification and it was important to fix the fragment of volar lunate facet fragment (VLF fragment). We also reported 20 cases of palmar subluxation, and 17 cases of them were Smith's or volar Barton's fractures. From our data, the average of longitudinal distance of VLF fragment was under 10 mm, and only 34% of VLF fragment was supported with the plate. As our strategy for volar-displaced distal radius fractures, we place Polyaxial Locking Plate (PLP) as distally and ulnar as possible. This time, we report the treatment result of volar-displaced distal radius fractures including marginal fractures.

Methods: The number of cases that had been operated for distal radius fractures in Showa University after 2015 were 131 hands of dorsal-displaced type and 35 hands of volar-displaced type. Among the latter, 33 hands, which are followed up more than six months, were subjected to this study. The mean age was 60.3 years old, male: female was 11:22 cases, and the mean follow-up period was 9.5 months. For CT in pre-operation, there were 9 hands (27.3%) of double fracture-line in VLF fragment and 7 hands (21.2%) of palmar subluxation. Monoaxial Locking Plate (MLP) were used for 4 hands and PLP for 29 hands. As the mean followed up period was 9.5 months. As for an additional procedure, spring wire fixation by Moore were used for 5 hands, plate with mini-plate was used for 1 hand, and artificial bone was used for 8 hands. We investigated the clinical evaluation, the radiological evaluation and complications of these cases.

Results: For the all cases, fractures were united. The correction loss of various parameters was slight (UV: VT: RI was 0.9 mm: 0.2 degrees: 0.8 degrees). The mean of the modified Mayo score was 86.2 points. As the complications, palmar subluxation were 2 cases, carpal tunnel syndrome was 1 case, ulnar abutment syndrome was 1 case and CRPS was 1 case.

Conclusion: The results of our treatment for volar-displaced distal radius fractures were almost good, but there were two cases of palmar subluxation after volar plating. For prevention of palmar subluxation, it is important to support the VLF fragment perfectly. We should select rim plates or some additional procedures for the cases under 10 mm of longitudinal VLF fragment.