Kirschner Wire Fixation in Dorsally Displaced Distal Radius Fractures: A Biomechanical Evaluation

Comparative Biomechanical Analysis of Kirschner Wire Fixation in Dorsally Displaced Distal Radius Fractures

OBJECTIVE

This study aims to evaluate and compare the biomechanical performance of two Kirschner (K) wire configurations-the intra-focal and interfragmentary techniques-for the fixation of dorsally displaced distal radius fractures. The study also assesses the impact of K-wire diameter (1.6 mm vs. 2.0 mm) on mechanical stability.

METHODS

Sixty fresh turkey tarsometatarsus bones were selected and divided into four groups based on the K-wire configuration and diameter used. Fractures were created at standardized locations, and each bone was stabilized using either the intra-focal also known as modified Kapandji (Ka) or interfragmentary technique. Mechanical testing, including axial compression and flexion tests, was performed to assess the biomechanical stability of each configuration.

RESULTS

The interfragmentary configuration consistently demonstrated superior biomechanical performance compared to the intra-focal technique. Specifically, the use of 2.0 mm K-wires resulted in significantly higher axial stiffness (13.28 MPa) and load at break (3070 N) compared to the 1.5 mm wires. Confidence intervals further supported the robustness of these findings. The interfragmentary technique, especially with thicker K-wires, provided greater load-bearing capacity and stiffness.

CONCLUSION

The interfragmentary technique with 2.0 mm K-wires offers superior mechanical stability compared to the intra-focal technique, making it the preferred choice for stabilizing comminuted extra-articular distal radius fractures. These findings suggest that adopting this technique may reduce the risk of postoperative complications such as fracture displacement or malunion. Further research involving osteoporotic bone models and clinical trials is recommended to validate these findings in real-world settings.

Treatment of distal radius fractures using a cemented K-wire frame

BACKGROUND

This retrospective study included an alternative treatment for types A2, A3, and B1 distal radius fractures using percutaneous fixation with a cemented K-wire frame.

METHODS

From January 2017 to January 2020, 78 patients with distal radius fractures were treated with percutaneous internal fixation using a cemented K-wire frame. There were 47 male patients and 31 female patients. The fractures were classified into types A2 (n = 10), A3 (n = 46), and B1 (n = 22). X-rays were taken immediately after surgery and after the bone had healed. Wrist function was assessed using the Mayo Wrist Score (90-100, excellent; 80-90, good; 60-80, satisfactory; < 60, poor). Patient satisfaction was assessed using the 10-cm visual analog scale.

RESULTS

Neither fixation failure nor K-wire migration was found (P > 0.05). Osteomyelitis was not observed in this series. All patients achieved bone healing after a mean of 4.5 weeks (range, 4 to 8 weeks). Follow-up lasted a mean of 27 months (range, 24 to 33 months). The mean score of wrist function was 97 (range, 91 to 100). Among them, 66 results were excellent and 12 results were good. The mean patient satisfaction was 10 cm (range, 8 to 10 cm).

CONCLUSIONS

Percutaneous fixation with cemented K-wire frame is a safe and preferred choice for the treatment of types A2, A3, and B1 distal radius fractures. The frame provides support to prevent wire migration. The fixation technique is a minimally invasive procedure that is easy to perform.

LEVEL OF EVIDENCE

Therapeutic study, Level IVa.