Amirouche Farid, Mzeihem Majd, Hoag Jasper, Wangikar Rohan, Koh Jason
Department of Orthopaedic Surgery, University of Illinois at Chicago, Chicago, Illinois.
Department of Orthopaedic Surgery, Northshore University Health System, An Affiliate of the University of Chicago Pritzker School of Medicine. Skokie, Illinois.
JB JS Open Access. 2025 Jul 17;10(3). doi: 10.2106/JBJS.OA.25.00032. eCollection 2025 Jul-Sep.
Understanding patellofemoral contact pressure is crucial for knee biomechanics, as abnormalities can lead to joint issues. This study investigates the changes in contact pressure after surgical fixation of patellar fractures.
Finite element model of the knee was created using cadaveric data on transverse patellar fractures. Models were analyzed and evaluated at 0°, 45°, and 90° flexion under quadriceps force to assess peak pressure, contact pattern, and pressure irregularity.
The plate and wire fixation models exhibited distinct stress distribution patterns at 45° and 90° flexion angles. At 45°, the plate model had a higher peak stress (6.14 MPa) in a 21.0-mm ovular contact area, while the wire model had lower peak stress (2.42 MPa) in a smaller, more fragmented region. At 90°, the plate model exhibited concentrated stress (13.26 MPa) in a heart-shaped area, whereas the wire model had 3 dispersed stress points (9.88 MPa) over a broader surface. These findings highlight the plate model's greater stress concentration and the wire model's more irregular distribution of stress. At 0°, the plate model exhibited minimal contact pressure compared with the wire model, with a pressure of 6.67 MPa.
The plate model better preserves patellofemoral biomechanics, potentially reducing complications and improving long-term outcomes. Further research is needed to confirm its superiority as a fixation method.
Although the prevalence of patellar fractures remains high, the gold-standard method for surgical fixation has a postoperative complication rate as high as 52.5%. Addressing the lack of understanding surrounding patellofemoral contact pressure in this scenario is an essential step toward improving outcomes for these patients.
了解髌股关节接触压力对于膝关节生物力学至关重要，因为异常情况可能导致关节问题。本研究调查了髌骨骨折手术固定后接触压力的变化。
利用尸体横断髌骨骨折数据创建膝关节有限元模型。在股四头肌力量作用下，于0°、45°和90°屈曲位对模型进行分析和评估，以评估峰值压力、接触模式和压力不规则性。
钢板和钢丝固定模型在45°和90°屈曲角度时呈现出不同的应力分布模式。在45°时，钢板模型在21.0毫米的椭圆形接触区域具有较高的峰值应力（6.14兆帕），而钢丝模型在较小且更分散的区域具有较低的峰值应力（2.42兆帕）。在90°时，钢板模型在心脏形区域表现出集中应力（13.26兆帕），而钢丝模型在更宽的表面上有3个分散的应力点（9.88兆帕）。这些发现突出了钢板模型更大的应力集中和钢丝模型更不规则的应力分布。在0°时，与钢丝模型相比，钢板模型的接触压力最小，为6.67兆帕。
钢板模型能更好地保留髌股关节生物力学，可能减少并发症并改善长期预后。需要进一步研究以证实其作为固定方法的优越性。
尽管髌骨骨折的患病率仍然很高，但手术固定的金标准方法术后并发症发生率高达52.5%。在这种情况下，解决对髌股关节接触压力缺乏了解的问题是改善这些患者预后的重要一步。
