Does proximal femoral nail antirotation achieve better outcome than previous-generation proximal femoral nail?

Biomechanical evaluation of a new intramedullary nail compared with proximal femoral nail antirotation and InterTAN for the management of femoral intertrochanteric fractures

Purpose: Surgical treatment is the main treatment method for femoral intertrochanteric fractures (FIFs), however, there are lots of implant-related complications after surgery. Our team designed a new intramedullary nail (NIN) to manage such fractures. The purpose of this study was to introduce this new implant and compare it with proximal femoral nail antirotation (PFNA) and InterTAN for treating FIFs. Methods: An AO/OTA 31-A1.3 FIF model was built and three fixation models were created via finite element method, comprising PFNA, InterTAN, and the NIN. Vertical, anteroposterior (A-P) bending, and torsional loads were simulated and applied to the three fixation models. Displacement and stress distribution were monitored. In order to compare PFNA and the NIN deeply, finite element testing was repeated for five times in vertical load case. Results: The finite element analysis (FEA) data indicated that the NIN possessed the most outstanding mechanical properties among the three fixation models. The NIN model had lower maximal stress at implants compared to PFNA and InterTAN models under three load conditions. The trend of maximal stress at bones was similar to that of maximal stress at implants. Besides, the NIN model showed smaller maximal displacement compared with PFNA and InterTAN models under vertical, A-P bending, and torsional load cases. The trend for maximal displacement of fracture surface (MDFS) was almost identical with that of maximal displacement. In addition, there was significant difference between the PFNA and NIN groups in vertical load case (p < 0.05). Conclusion: Compared with PFNA and InterTAN, the NIN displayed the best mechanical properties for managing FIFs, including the lowest von Mises stress at implants and bones, and the smallest maximal displacement and MDFS under vertical, A-P bending, and torsional load cases. Therefore, this study might provide a new choice for patients with FIFs.

Treatment of Coronal Plane Femoral Intertrochanteric Fractures with a Microexternal Fixator Combined with Proximal Femoral Nail Antirotation

OBJECTIVE

To investigate the different efficacy of proximal femoral nail antirotation (PFNA) combined with or without a microexternal fixator in the treatment of coral-plane femoral intertrochanteric fractures.

METHODS

120 patients with intertrochanteric coronal fractures who received treatment in four hospitals from February 2020 to February 2021 were retrospectively included in this study. They were divided into control (PFNA alone, n = 60) and combined treatment group (a microexternal fixator + PFNA, n = 60) according to different surgery methods. All patients were followed up for 6 months. Operative time, amount of intraoperative blood loss, postoperative length of hospital stays, fracture healing time, Harris hip score, modified Barthel index, hip function excellent and good rate, and incidence of complications were compared between the two groups.

RESULTS

There were no significant differences in operative time, amount of intraoperative blood loss, postoperative length of hospital stay, and incidence of complications between the two groups (all P > 0.05). Fracture healing time in the combined treatment group was significantly shorter than that in the control group (P < 0.05). After surgery, Harris hip score and modified Barthel index in each group were significantly increased compared with before surgery (both P < 0.05). The increases in Harris hip score and modified Barthel index in the combined treatment group were significantly greater than those in the control group (both P < 0.05). After surgery, Harris hip function excellent and good rate in the combined treatment group was significantly higher than that in the control group (83.33% > 66.67%, P < 0.05).

CONCLUSION

Compared with PFNA alone, a microexternal fixator combined with PFNA for the treatment of coronal plane femoral intertrochanteric fractures can greatly shorten fracture healing time and improve postoperative hip function and activities of living ability, but it cannot greatly increase operative time, the amount of intraoperative blood loss, or the risk of postoperative complications.