Radiological factors causing anterior knee pain after intramedullary nailing of tibial shaft fractures

Abstract

Aims: Intramedullary nailing (IMN) is the most common method for treating tibial shaft fractures. Though the procedure preserves the soft tissue envelope around the fracture and enables weight-bearing on the affected limb, chronic anterior knee pain may still occur. The aim of this study was to evaluate radiological factors of anterior knee pain in patients undergoing tibial IMN. Methods: Patients were retrospectively analyzed as part of the study. The distance from the proximal tip of the nail to the tibial plateau in the sagittal plane, the distance from the tip of the nail to the anterior tibial cortex, the distance from the nail entry point to the tibial mechanical axis in the anteroposterior (AP) plane, the Caton-Deschamps index, the Insall-Salvati index, and the visual analog scale (VAS) scores were evaluated. Results: The study included 147 patients [age, mean±standard deviation (SD): 37.51±14.61 years; 99 (67.4%) male].The mean postoperative 12th month VAS pain score was 4.56±2.52. No significant correlation was found between VAS scores and factors such as the distance from the proximal tip of the nail to the tibial plateau in the sagittal plane, the distance from the tip of the nail to the anterior tibial cortex, Caton-Deschamps index, or Insall-Salvati index (p>0.05). However, a significantly positive correlation was observed between the distance from the nail entry point to the tibial mechanical axis in the AP plane, and VAS score (r=0.701, p=0.001). Conclusions: Our study results indicated that when the entry point of the nail deviated further from the tibial mechanical axis, as evaluated at 12 months postoperatively, the VAS score of the patients increased. Ensuring that the nail entry point is accurately positioned within the designated safe zone is critical.

Keywords

• tibial shaft fracture
• intramedullary nailing
• anterior knee pain
• mechanical axis deviation