[A preliminary report of open reduction and Numelock II polyaxial system fixation for type C fracture of distal radius].

OBJECTIVE

To study the clinical outcomes of Numelock II polyaxial system in treatment of type C fractures of the distal radius.

METHODS

From March 2006 to June 2007, 12 cases of type C distal radial fractures (6 males and 6 females) were treated with open reduction and internal fixation. The mean age of the patients was 48.2 years (34-64 years). The locations were left wrist in 5 cases and right wrist in 7 cases, including 1 case of old fracture and 11 cases of fresh fractures. All fractures were closed. The mean course of disease was 9 days and 7 hours (4 hours to 60 days). According to AO/ASIF classification, there were 4 cases of C1 type, 5 cases of C2 type and 3 cases of C3 type. Preoperatively, the palmar tilt angle was -30 degrees to 30 degrees (- 5 degrees on average), and the radial inclination angle was 5 degrees to 13 degrees (7.7 degrees on average), and the radial shortening was 5 mm to 15 mm (9 mm on average). One case combined with dislocation of elbow joint and 2 cases combined with multiple injuries.

RESULTS

All incision healed by first intention. Postoperative follow-up ranged from 14 months to 29 months (15.6 months on average). The X-ray films showed that the union of fractures was achieved 6-8 weeks (6.6 weeks on average). No screws breakage occurred. The articular facets were smooth in 11 of 12 patients. After operation, the palmar tilt angle was 0 degrees to 15 degrees (6.7 degrees on average), and the radial inclination angle was 5 degrees to 15 degrees (10.2 degrees on average), showing significant differences when compared with those before operation (P < 0.05). All the radial shortening was corrected. The ROM of the wrist was 55%-100% of the normal side. The grip strength was 55%-90% of the normal side. The results were excellent in 9 cases, good in 2 cases, and poor in 1 cases by X-ray film and wrist function assessment, the excellent and good rate was 91.7%.

CONCLUSION

Numelock II polyaxial system fixation is an ideal method to treat type C fractures of the distal radius. Numelock II polyaxial mechanism may provide the free adjustability of screw trajectories and a higher degree of overall stability compared to monoaxial locking plates.