Background: The purpose of this study was to compare the stability of the 2.4 mm palmar locking compression plate (LCP) and a new intramedullary nail-plate-hybrid Targon DR (TDR) for dorsally comminuted distal radius fractures.

Methods: An extraarticular 10 mm dorsally open wedge osteotomy was created in 8 pairs of fresh frozen distal radii to simulate an AO-A3-fracture. The fractures were stabilized with one of the fixation constructs. The specimens were loaded axially with 200 N and dorsal-excentically with 150 N. Cyclic loading with 2000 cycles as well as loading to failure were performed under axial loading.

Results: Axial loading revealed that intramedullary osteosynthesis (Targon DR: 369N/mm) was significantly (p=0.017) stiffer than plate osteosynthesis (LCP: 131 N/mm). With 214 N/mm the intramedullary nail was also more stable during dorsal excentric loading than the LCP with 51 N/mm (p=0.012). After the 2000 cycles of axial loading with 150 N the Targon group was still significant stiffer than the LCP group under both loading patterns. Neither group showed a significant change in stiffness after the 2000 cycles. The Targon DR group even showed a slight increase with 435,22 N/mm (p = 0.161), while the LCP group showed a slight decrease with 122.24 N/mm (p = 0.575) during axial loading. Under dorsal excentric loading the Targon group was still significant stiffer with 212.46 N/mm than the LCP group with 44.96 N/mm (p=0.012). The load to failure tests demonstrated again the superiority of intramedullary nailing (625N) when compared to plate osteosynthesis (403N) (p< 0.025).

Conclusions: The study shows that both implants are able to withstand physiological loads occuring under unloaded wrist motion. Neither implant showed a significant loss of stability after 2000 cycles long-term loading. Intramedullary nailing with the Targon DR of a distal A3 radial fracture is biomechanically more stable than volar fixed angle plating with the 2.4 mm LCP under axial and dorsal-excentric loads in our experimental setup.

Objective: Osteoporotic fractures of the distal forearm are demanding in terms of operative therapy and implants used. Volar fixed angle plating has become a standard procedure for these fractures. Recently intra-medullary nailing was introduced in clinical practice for the use in distal radial fractures. This randomized multi-center study compares both fixation techniques in terms of clinical and radiological outcome as well as quality of life score.

Material and Methods: Up to now a total of 85 patients with extra- and intraarticular unstable fractures of the distal radius were included. 53 patients (Targon DR®, B. Braun-Aesculap: n=24; 2.4 mm plate, Synthes: n=29) completed the 6 months follow-up. Follow up examinations included an osteodensitometry using pQCT, X-ray analysis and a detailed clinical function examination. In addition the SF36 questionaire for quality of life assessment was carried out.

Results: The operation time for volar plating was significantly longer than for intramedullary nailing (50.3±20.2 min versus 40.2±13.4 min), as was the time in hospital (5.4±1.8 days versus 2.2±0.6 days) (MW±SD; p< 0.05; Student-t-Test, post hoc: Bonferonni). The Gartland an Werley function score averaged 2.7±1.1 versus 1.9±0.8 for volar plating in comparision to treatment with the Targon DR® nail and thus just failed to reach statistical significance (p = 0.052). Radiological Evaluation revealed bony healing in all patients of both groups. Radial length was maintained in all but one patient (96%) in the nailing group and all but 2 patients (93%) in the plating group. A loss of volar tilt −5°was seen in 1 patient in the nailing group (4%) and 3 patients in the plating group (10%). Of interest radiological signs of bony healing developed much faster after intramedullary nailing. The Quality of life as measured by the SF36 was minimaly diminished in both groups (body/social function: Targon DR®: 56.3±25.1/63.4±21.2 points − 2.4 mm plate: 52.8±23.3/60.5±23.3 points). Osteoporotic bone loss was detected in a total of 72% of patients. Osteoporosis had no adverse effects on bony healing or functional parameters. We encountered two complications. One mild CRPS (volar plating) and in one case paraesthesia of the R. superficialis n. radialis (intramedullary nailing).

Conclusion: Both intramedullary nailing with the Targon DR® nail and volar plating using a 2.4 mm volar fixed angle plate allows stable fixation of osteoporotic distal forearm fractures. Lower operation time and minimally invasive operative procedure of intramedullary nailing is accompanied by faster mobilization.