University of Texas Health Science Center, Houston, TX, USA.
Cantonal Hospital Graubünden, Chur, Switzerland.
Arch Orthop Trauma Surg. 2024 May;144(5):2131-2140. doi: 10.1007/s00402-024-05266-w. Epub 2024 Mar 23.
Treatment of both simple and complex patella fractures is a challenging clinical problem. Although tension band wiring has been the standard of care, it can be associated with high complication rates. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures.
Sixteen pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior (central distal) fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full extension. Interfragmentary movements were captured via motion tracking.
For both fracture types, the articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p ≤ 0.01.
From a biomechanical perspective, lateral rim variable angle locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.
无论是简单还是复杂的髌骨骨折的治疗都是一个具有挑战性的临床问题。尽管张力带钢丝固定一直是标准的治疗方法，但它可能会导致较高的并发症发生率。本研究旨在探讨最近开发的外侧边缘变角锁定板与张力带钢丝固定治疗简单和复杂髌骨骨折的生物力学性能。
使用 16 对人体解剖膝关节来模拟通过截骨术产生的两部分横断简单 AO/OTA 34-C1 或五部分复杂 AO/OTA 34-C3 髌骨骨折，每个骨折模型在 8 对中创建。复杂骨折模式的特点是内侧和外侧近端骨折块，以及内侧下、外侧下和下（中央远端）骨折块，模拟围绕远端髌骨末端的粉碎。具有简单骨折的标本通过两条平行的空心螺钉穿过张力带钢丝或外侧边缘变角锁定板进行成对固定。复杂骨折的膝关节通过两条平行的空心螺钉加上环绕的环扎钢丝穿过张力带钢丝或外侧边缘变角锁定板进行成对治疗。每个标本通过在 5000 次循环中拉动股四头肌肌腱进行测试，模拟主动膝关节伸展和被动膝关节屈曲在 90°屈曲至完全伸展范围内。通过运动跟踪捕获骨折块间的运动。
对于两种骨折类型，在 1000 至 5000 次循环之间，在髌骨中央部位测量的近端和远端骨折块之间的关节位移，以及这些骨折块围绕内外侧轴的相对旋转，与张力带钢丝固定相比，使用外侧边缘变角锁定板固定后均显著减小，p≤0.01。
从生物力学角度来看，在动态加载下，外侧边缘变角锁定板固定无论是简单还是复杂的髌骨骨折，其固定稳定性均优于张力带钢丝固定。
