Comparison of the clinical efficacy of different fixation systems for the treatment of transverse patellar fractures

Abstract

Purpose: This study was designed to compare the clinical efficacy of "8" and "0" wire fixation systems combined with double-head cannulated compression screws or Kirschner wires for the treatment of transverse patellar fractures.

Methods: From September 2011 to September 2018, patients with closed transverse patellar fractures treated with a double-head compression screw or Kirschner wire were included and analyzed retrospectively. Patients with patellar fractures combined with distal femoral fractures, tibial plateau fracture or preoperative lower limb dysfunction were excluded. The patients treated with the "8" tension band wire fixation system and Kirschner wire were taken as Group A; those treated with the "0" fixation system and Kirschner wire were taken as Group B; those treated with the "8" fixation system and double-head cannulated compression screw were taken as group C; and those treated with the "0" fixation system and double-head cannulated compression screw were taken as group D. Six weeks and one year after the operation and every month from the third month after the operation until the fractures healed, an X-ray examination was performed to identify fracture healing. The time of fracture healing and postoperative complications of the four groups were compared. One year after the operation, knee function was evaluated by Bostman's score.

Results: During the study period, 168 patients with patellar fractures were treated by operations, and 88 patients were excluded because the fracture type did not meet the requirements or because there were combined fractures of the distal femur or tibial plateau. As a result, 80 patients were included in this study, 20 in each group. All the patients were followed up for an average period of 12.2 months. Compared with Group A, patients in Group D presented less postoperative discomfort in the prepatellar region, quicker fracture healing, less fixation failure and better postoperative knee function scores (all p < 0.05). The incidence of internal fixation failure in Group (B+D) was lower than that in Group (A+C) (p > 0.05).

Conclusion: The "0" wire fixation system combined with a double-head cannulated compression screw seems to be more beneficial than the other three fixation systems for the treatment of transverse patellar fractures.

Keywords: Double-head cannulated compression screw; Transverse patellar fractures; “0” fixation system.

Fig. 1

X-ray images of transverse patellar fractures fixed by four different fixation systems. (A, B, E, F, I, J, M and N) X-ray images obtained one day after the operation; (C, D, G, H, K, L, O, and P) X-ray images obtained when the fractures healed. A, B, C, D and E, F, G, H represent the transverse patellar fractures fixed by Kirschner wire combined with “8” or “0” wire fixation systems; I, J, K, L and M, N, O, P represent the transverse patellar fractures fixed by double-head cannulated compression screws combined with “8” or “0” wire fixation systems.