Purpose

In patients with open growth plates, the direction of tunneling that avoids distal femoral physis (DFP) damage in anatomic reconstructions of the medial patellofemoral ligament (MPFL) has been a topic of discussion. The objective of this study was to determine the ideal orientation for anatomic reconstructions of MPFL tunneling that minimized DFP damage while avoiding breaching the intercondylar notch.

Methods

Eighty magnetic resonance images of patients aged 10 through 17 were obtained, randomly sampled from the institutional database. A de novo software was developed to obtain 3D models of the distal femur and DFP. In each model, the anatomical insertion point of the MPFL was determined as defined by Stephen. A 20-mm-depth drilling was simulated, starting from the insertion point at every possible angle within a 90° cone using 5-, 6- and 7-mm drills. Physeal damage for each pair of angles and each drill size was determined. Damage was expressed as a percentage of total physis volume. Statistical analysis was conducted using Student’s t test and one-way ANOVA.

Results

Maximum physeal damage (5.35% [4.47–6.24]) was obtained with the 7-mm drill when drilling 3° cephalic and 15° posterior from insertion without differences between sexes (n.s.). Minimal physeal damage (0.22% [0.07–0.37]) was obtained using the 5-mm drill aimed 45° distal and 0° anteroposterior, not affected by sex (n.s.). Considering intra-articular drilling avoidance, the safest zone was obtained when aiming 30°–40° distal and 5°–35° anterior, regardless of sex.

Conclusion

Ideal femoral tunnel orientation, avoiding physeal damage and breaching of the intercondylar notch, was obtained when aiming 30°–40° distal and 5°–35° anterior, regardless of sex. This area is a safe zone that allows anatomic MPFL reconstruction of patients with an open physis.

中文翻译：

---

对于开放性生长板患者，for股韧带内侧解剖重建的前，远侧隧道方向更安全。

目的

对于生长板开放的患者，在pa股内侧韧带（MPFL）解剖重建中避免远端股骨物理（DFP）损伤的隧穿方向一直是讨论的主题。这项研究的目的是确定MPFL隧道的解剖结构重建的理想方向，该结构可最大程度地减少DFP损伤，同时避免破坏breach间切口。

方法

从机构数据库中随机抽取了80例10至17岁患者的磁共振图像。开发了从头软件来获取股骨远端和DFP的3D模型。在每个模型中，MPFL的解剖插入点均由Stephen定义。模拟了20毫米深的钻孔，使用5毫米，6毫米和7毫米钻头从插入点开始，在90°圆锥内的每个可能角度开始。确定每对角度和每种钻头尺寸的物理损伤。损害表示为总物理体积的百分比。使用学生t检验和单向方差分析进行统计分析。

结果

当从插入时向头向后头钻3°和向后头钻15°时，使用7毫米钻头可获得最大的植骨损伤（5.35％[4.47–6.24]），无性别差异（ns）。使用5毫米钻头对准远端45°和前后0°，获得最小的骨eal损伤（0.22％[0.07–0.37]），不受性别（ns）的影响。考虑到避免关节内钻孔，无论性别如何，在向远端30°–40°和向前5°–35°瞄准时都可获得最安全的区域。

结论

当对准远端30°–40°和向前5°–35°时，无论性别，均可获得理想的股骨隧道方向，从而避免骨赘损伤和breach间缺口的破坏。该区域是一个安全区域，允许开放性生理的患者进行解剖学MPFL重建。