Bond Sarah, Rust Philippa, Boland Maria
Anatomy, University of Edinburgh, Edinburgh.
Hooper Hand Surgery Unit, St. John's Hospital, Livingston, Scotland.
J Hand Surg Am. 2019 Nov;44(11):986.e1-986.e6. doi: 10.1016/j.jhsa.2018.12.012. Epub 2019 Feb 15.
Avulsion injury of the flexor digitorum profundus (FDP) tendon has been traditionally repaired with a pull-out suture over the nail plate. Complication rates with this method and improvements in anchor design have led to the increased use of bone anchors to give a rigid all-inside repair. However, the dimensions of the distal phalanx may limit their use. The primary hypothesis was that 2 micro bone anchors could fit in either perpendicular or 45° proximally angled positions within each distal phalanx. A further hypothesis was that 1 mini bone anchor could fit in similar positions in the distal phalanx.
Thirty-two fresh frozen fingers were dissected, and the FDP tendon was removed from the distal phalanx footprint. Two bone anchor types were used, mini and micro sizes, and inserted at 2 angles, perpendicular and 45° proximally angled. Observations of dorsal cortex and joint space penetration were recorded. Distal phalanx dimensions were measured for each finger.
The micro anchors penetrated the dorsal cortex in perpendicular tests in little fingers only. The micro anchor did not penetrate the joint in any angled tests. The mini bone anchor penetrated the dorsal cortex in 100% of perpendicular tests and the joint in 63% of angled tests, although none of these included the middle finger.
Two micro bone anchors fit within the distal phalanx in all fingers tested, except the little finger, when placed in the perpendicular position. At a 45° angle, the distal phalanx of the little finger can also accommodate micro bone anchors without any evidence of complication when placed 4 mm from the joint. The mini anchors were too large to fit in a perpendicular position within the distal phalanx. In the 45° angled position, the joint was not penetrated by the mini anchor in only middle fingers.
The study provides anatomical evidence of the accommodation of micro bone anchors within the distal phalanx in perpendicular or 45° angled positions for the repair of FDP tendon avulsion injury.
传统上，指深屈肌腱（FDP）撕脱伤采用经甲板抽出缝合法修复。该方法的并发症发生率以及锚钉设计的改进，使得骨锚在刚性全内置修复中的应用增加。然而，远节指骨的尺寸可能会限制其使用。主要假设是，两枚微型骨锚可以以垂直或近端成45°角的位置置入每个远节指骨内。另一个假设是，一枚微型骨锚可以以类似的位置置入远节指骨内。
解剖32根新鲜冷冻手指，从远节指骨附着处移除FDP肌腱。使用两种类型的骨锚，微型和小型，以垂直和近端成45°角两种角度插入。记录对背侧皮质和关节间隙穿透情况的观察结果。测量每根手指远节指骨的尺寸。
在垂直测试中，微型锚仅在小指中穿透背侧皮质。在任何角度测试中，微型锚均未穿透关节。小型骨锚在100%的垂直测试中穿透背侧皮质，在63%的角度测试中穿透关节，不过这些测试均未包括中指。
在所有测试手指中，除小指外，垂直放置时，两枚微型骨锚均可置入远节指骨内。呈45°角时，从小指远节指骨距关节4 mm处放置微型骨锚，也可容纳且无任何并发症迹象。小型锚太大，无法垂直置入远节指骨内。呈45°角时，仅在中指中，小型锚未穿透关节。
该研究为在修复FDP肌腱撕脱伤时，微型骨锚以垂直或45°角位置置入远节指骨内提供了解剖学依据。
