Hammarstedt Jon E, Redshaw James T, Schimoler Patrick J, Westrick Edward R, Andreini Derek, Kharlamov Alexander, Miller Mark Carl
Allegheny Health Network, Department of Orthopaedic Surgery, Pittsburgh, PA, 15212, USA.
University of Pittsburgh, Department of Mechanical Engineering and Materials Science, Pittsburgh, PA, 15213, USA.
J Clin Orthop Trauma. 2022 Aug 27;33:101998. doi: 10.1016/j.jcot.2022.101998. eCollection 2022 Oct.
The standard treatment of calcaneus fractures is a lateral plate and screw construct. Patients at our institution have been treated with a lateral locking plate combined with one retrograde screw inserted in the oblique plane to allow immediate weight bearing. The purpose of this study was to determine whether addition of a oblique screw to a lateral plate construct increases stability.
A Sanders 2B fracture (AO/OTA 83-C2) was created in 8 pairs (16 total specimens) of cadaveric feet. All were repaired using a lateral locking plate/screws construct. One specimen in each pair was chosen randomly to receive an additional oblique screw. The specimens were tested with cyclic load of up to 800 N. Movement at the fracture sites and subsidence of the talus were tracked with a three-dimensional video analysis system.
Talar subsidence was not significantly affected by the presence of the additional oblique screw (p = 0.22). The sustentaculum fragment in the case of the screw repair moved 0.39 mm while the same fragment without the additional screw repair displaced 0.12 mm (p < 0.01). Two repairs with and one repair without the additional screw failed during longer-term cyclic loading.
The two repair types were not statistically different in regards to talar subsidence. While statistical significance resulted in the comparison of sustentaculum fragment movement, the amount of movement did not reach a level of clinical relevance. This study demonstrated immediate stability and durability of the additional screw construct with high volume weight bearing loads.
跟骨骨折的标准治疗方法是使用外侧钢板和螺钉固定结构。在我们机构，患者接受外侧锁定钢板联合一枚沿斜平面插入的逆行螺钉治疗，以允许早期负重。本研究的目的是确定在外侧钢板固定结构中增加一枚斜向螺钉是否能提高稳定性。
在8对（共16个标本）尸体足上制造Sanders 2B型骨折（AO/OTA 83-C2）。所有骨折均采用外侧锁定钢板/螺钉固定结构进行修复。每对标本中随机选取一个额外植入一枚斜向螺钉。使用高达800 N的循环载荷对标本进行测试。采用三维视频分析系统跟踪骨折部位的移位及距骨的沉降情况。
额外斜向螺钉的存在对距骨沉降无显著影响（p = 0.22）。螺钉固定组的载距突骨折块移位0.39 mm，未植入额外螺钉组的相同骨折块移位0.12 mm（p < 0.01）。在长期循环加载过程中，两枚植入额外螺钉的修复和一枚未植入额外螺钉的修复失败。
两种修复方式在距骨沉降方面无统计学差异。虽然在比较载距突骨折块移位时有统计学意义，但移位量未达到临床相关水平。本研究表明，额外螺钉固定结构在高负荷负重情况下具有即时稳定性和耐久性。
