Functional Outcomes in Volar-Displaced Distal Radius Fractures Patients with Marginal Rim Fragment Treated by Volar Distal Locking Plates

Abstract

Background Treatment of volar-displaced distal radius fractures (DRF) accompanied by marginal rim fragment has recently been actively discussed. It is difficult to obtain a sufficient buttress effect on this fragment. Therefore, we actively apply a distal volar locking plate (DVLP) to fractures with this fragment. Here, we report the treatment outcomes and caveats of surgery of fractures with this fragment. Materials and Methods The subjects were 32 patients (male: 11, female: 21, and mean age: 59.4 years) with volar dislocated DRF accompanied by the marginal rim fragment treated using DVLP. The fracture type of AO classification was B3 in 6 patients, C1 in 12, C2 in 6, and C3 in 8. Results The mean duration of follow-up was 13.8 (12-30) months. The plate could be covered with the pronator quadratus muscle in surgery in all patients. On the final follow-up, visual analog scale score was 1.4/10, quick disabilities of the arm, shoulder, and hand score was 9.2/100, and the Mayo wrist score was 93.7/100. No complication was observed in the soft tissue, such as the nerves and flexor tendons. Conclusion The factor determining retention of the reduction position of the marginal rim fragment is a sufficient buttress effect, and DVLP is a useful implant in terms of this point.

Keywords: buttress effect; distal radius fractures; marginal rim fragment; volar displaced; volar distal locking plates.

Fig. 1

The treatment algorithm for distal radius fractures in our department. Volar-displaced fractures are good indication of DVLP. Moreover, the selection of DVLP in our study (Acu-Loc 2 DVLP or Volar rim plate) depended on the size of volar displaced fragments or amount of volar displacement. DVLP, distal volar locking plate.

Fig. 2

Processing of the pronator quadratus muscle. ( A ) The pronator quadratus muscle was incised only on the radial side to make restoration after setting the plate easy. The muscle body was dissected from the radial attachment side, and dissection was carefully advanced to the distal attachment site. Setting the plate is also possible. ( B ) An exposure method conserving the pronator quadratus muscle to the distal side, such as this surgical procedure, the muscle can be easily restored after placing the plate.

Fig. 3

Osteosynthesis with DVLP. ( A ) The patient had type C1 volar displaced distal radius fracture with marginal rim fragment. ( B ) Osteosynthesis with DVLP was performed. ( C ) The plain radiography of lateral view showed the reduction of volar displacement. DVLP, distal volar locking plate.

Fig. 4

Characteristics of distal volar locking plate (DVLP) and proximal volar locking plate (PVLP). ( A ) DVLP is capable of vertically pressing the distal fragment from the volar to dorsal side (arrow is showing the force direction). ( B ) PVLP pushes the distal fragment toward the dorsal distal side due to the shape of the distal region (arrow is showing the force direction). ( C ) When the plate interferes with the flexor tendon, the distal end of the plate of PVLP interferes with the flexor tendon at a “point” (circle is showing the area of the interference). ( D ) In contrast, the distal plate of DVLP interferes with the flexor tendon in a “plane,” and this may reduce the physical load on the flexor tendon. (circle is showing the area of the interference).