Walsh Justin M, Credille Kevin, Allahabadi Sachin, Kaplan Daniel J, Darbandi Azad D, Huddleston Hailey P, Hevesi Mario, Wang Zachary, Dandu Navya, Yanke Adam B
Houston Methodist Hospital, Houston, Texas, USA.
Midwest Orthopedics at Rush University Medical Center, Chicago, Illinois, USA.
Orthop J Sports Med. 2024 Jun 7;12(6):23259671241241537. doi: 10.1177/23259671241241537. eCollection 2024 Jun.
While the biomechanical properties of the native medial patellofemoral ligament (MPFL) have been well studied, there is no comprehensive summary of the biomechanics of MPFL reconstruction (MPFLR). An accurate understanding of the kinematic properties and functional behavior of current techniques used in MPFLR is imperative to restoring native biomechanics and improving outcomes.
To provide a comprehensive review of the biomechanical effects of variations in MPFLR, specifically to determine the effect of graft choice and reconstruction technique.
Systematic review.
A systematic review was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A total of 32 studies met inclusion criteria: (1) using ≥8 human cadaveric specimens, (2) reporting on a component of MPFLR, and (3) having multiple comparison groups.
Gracilis, semitendinosus, and quadriceps grafts demonstrated an ultimate load to failure (N) of 206.2, 102.8, and 190.0 to 205.0 and stiffness (N/mm) of 20.4, 8.5, and 21.4 to 33.6, respectively. Single-bundle and double-bundle techniques produced an ultimate load to failure (N) of 171 and 213 and stiffness (N/mm) of 13.9 and 17.1, respectively. Anchors placed centrally and superomedially in the patella produced the smallest degree of length changes throughout range of motion in contrast to anchors placed more proximally. Sutures, suture anchors, and transosseous tunnels all produced similar ultimate load to failure, stiffness, and elongation data. Femoral tunnel malpositioning resulted in significant increases in contact pressures, patellar translation, tilt, and graft tightening or loosening. Low tension grafts (2 N) most closely restored the patellofemoral contact pressures, translation, and tilt. Graft fixation angles variably and inconsistently altered contact pressures, and patellar translation and tilt.
Data demonstrated that placement of the MPFLR femoral tunnel at the Schöttle point is critical to success. Femoral tunnel diameter should be ≥2 mm greater than graft diameter to limit graft advancement and overtensioning. Graft fixation, regardless of graft choice or fixation angle, is optimally performed under minimal tension with patellar fixation at the medial and superomedial patella. However, lower fixation angles may reduce graft strain, and higher fixation angles may exacerbate anisometry and length changes if femoral tunnel placement is nonanatomic.
虽然对天然内侧髌股韧带（MPFL）的生物力学特性已有充分研究，但对于MPFL重建（MPFLR）的生物力学尚无全面总结。准确了解MPFLR中当前所用技术的运动学特性和功能行为对于恢复天然生物力学和改善治疗效果至关重要。
全面综述MPFLR变化的生物力学效应，特别是确定移植物选择和重建技术的影响。
系统评价。
按照PRISMA（系统评价和Meta分析的首选报告项目）指南进行系统评价。共有32项研究符合纳入标准：（1）使用≥8个尸体标本，（2）报告MPFLR的一个组成部分，（3）有多个比较组。
股薄肌、半腱肌和股四头肌移植物的极限破坏载荷（N）分别为206.2、102.8和190.0至205.0，刚度（N/mm）分别为20.4、8.5和21.4至33.6。单束和双束技术的极限破坏载荷（N）分别为171和213，刚度（N/mm）分别为13.9和17.1。与置于更靠近近端的锚钉相比，置于髌骨中央和上内侧的锚钉在整个运动范围内产生的长度变化最小。缝线、缝线锚钉和经骨隧道产生的极限破坏载荷、刚度和伸长数据相似。股骨隧道位置不当导致接触压力、髌骨平移、倾斜以及移植物收紧或松弛显著增加。低张力移植物（2N）最接近地恢复了髌股接触压力、平移和倾斜。移植物固定角度可变且不一致地改变接触压力以及髌骨平移和倾斜。
数据表明，将MPFLR股骨隧道置于朔特勒点对手术成功至关重要。股骨隧道直径应比移植物直径大≥2mm，以限制移植物推进和过度张紧。无论移植物选择或固定角度如何，移植物固定最佳在最小张力下进行，髌骨固定于髌骨内侧和上内侧。然而，如果股骨隧道位置不解剖，较低的固定角度可能会降低移植物应变，而较高的固定角度可能会加剧不等长和长度变化。
