Efficacy comparison of Kirschner-wire tension band combined with patellar cerclage and anchor-loop plate in treatment of inferior patellar pole fracture

Abstract

Objective: This study aimed to compare the biomechanical stability and clinical efficacy of the Kirschner-wire (K-wire) tension band combined with patellar cerclage and an anchor-loop plate (ALP) in treating inferior-pole patellar fracture.Methods: The finite element model was established to analyze the mechanical properties of a K-wire tension band combined with patellar cerclage and ALP fixation in the treatment of inferior patellar pole fracture. The clinical data of 49 patients with patellar inferior-pole fracture (AO/OTA 34 A1) admitted to our hospital from January 2017 to July 2021 were retrospectively analyzed. Among these, 28 cases were fixed with ALPs (ALP group) and 21 cases were fixed with K-wire tension bands combined with patellar cerclage (K-wire group). By reviewing the medical records and follow-up results, we compared the operation time, final knee joint activity, incidence of secondary surgery, postoperative complications, and joint function recovery between the two groups.Results: The biomechanical analysis of the finite element model showed that the maximum displacement of the K-wire group was 1.87 times that of the ALP group. The maximum stress of the K-wire group was 1.34 times that of the ALP group. The maximum stress of the pole bone in the K-wire group was 13.89 times that of the ALP group. The average follow-up times of the K-wire group and ALP group were similar (p > 0.05), and the average ages of the two groups were similar (p > 0.05). The operation time of the ALP group was significantly shorter than that of the K-wire group (p < 0.05).The final knee joint activity of the ALP group was significantly greater than that of the K-wire group (p < 0.05). The Bostman patellar fracture function score of the ALP group was significantly better than that of the K-wire group at 3 and 9 months after operation (p < 0.05). Postoperative complications of the two groups included 1 case (3.6%) in the ALP group with internal fixation-stimulation complications and, in the K-wire group, 3 cases (14.3%) with internal fixation stimulation complications and 1 case (4.8%) with infection.Conclusion: The ALP and K-wire tension band combined with patella cerclage models were tested at 500 N, and no damage occurred, indicating that the newly designed ALP is safe in mechanical structure. The ALP has better therapeutic effect in biomechanical stability, postoperative complications, secondary surgery, and knee function. This technique is an effective method for the treatment of inferior-pole patellar fracture.

Surgical treatment of inferior pole fractures of the patella: a systematic review

“…Rigid fixation devices included those using plates and screws ( n = 326, 8 studies; Fig. 1A) [6, 9, 18, 23, 27, 30–32] and concentrators ( n = 119, 2 studies; Fig. 1B) [4, 25].…”

“…Mixed devices included those fixed using TBW ( n = 294, 12 studies; Fig. 1F) [2, 3, 6, 8, 16, 22, 26, 35, 41, 44, 46, 48] or a similar technique with or without other augmentation ( n = 22, 1 study) [24]. These devices combined rigid fixation devices (e.g., interosseous K‐wire) and tensile fixation devices (e.g., figure‐8 wire).…”

“…1A ) or concentrators (Fig. 1B) [4, 6, 9, 18, 23, 25, 27, 30–32], and the use of separated vertical wiring (SVW; Fig. 1C ) [5, 7, 10, 20, 33, 38, 42, 43, 45], tension band wiring (TBW; Fig.…”

Model Properties and Clinical Application in the Finite Element Analysis of Knee Joint: A Review

“…92 Du et al compared the clinical effects and mechanical properties of different treatment methods for inferior pole fractures of the patella. 93 The anchor-loop plate had better biomechanical stability and clinical effect than the Kirschner wire tension band combined with patellar cerclage. 93 Overall, finite element analysis of the knee joint applied to fractures and bone defects can simulate the biomechanical results well and has good prospects for the research and treatment of fractures and bone defects.…”

“…Du et al . compared the clinical effects and mechanical properties of different treatment methods for inferior pole fractures of the patella 93 . The anchor‐loop plate had better biomechanical stability and clinical effect than the Kirschner wire tension band combined with patellar cerclage 93 …”