Department of Orthopaedic Surgery, University of Utah, Salt Lake City, UT.
Department of Orthopaedics, Phramongkutklao Hospital and College of Medicine, Tung Phayathai, Ratchathewi, Bangkok, Thailand ; and.
J Orthop Trauma. 2021 Dec 1;35(12):e463-e469. doi: 10.1097/BOT.0000000000002113.
To evaluate the accessible area of the talar dome through 2 standard posterior approaches [posteromedial (PM) and posterolateral (PL)] with and without distraction.
A standard PM or PL approach was performed with and without external fixator distraction on 12 through-knee cadaveric legs (6 matched pairs). The accessible area of the talar dome was outlined and imaged in a microcomputed tomography scanner to achieve 3D reconstructions of the accessible surface area. The study outcomes were accessible surface area of the talar dome in (1) total surface area and (2) sagittal plane distance of the talar dome at predetermined intervals.
The PM approach provided significantly more access to the talar dome than did the PL approach both with and without distraction (P < 0.001). The PM approach allowed access to 15.8% (SD = 4.7) of the talar dome without distraction and 26.4% (SD = 8.0, P < 0.001) of the talar dome with distraction. The PL approach provided access to 6.69% (SD = 2.69, P = 0.006 compared with PM) and 14.6% (SD = 6.24, P = 0.006 compared with PM) of the talar dome surface area without and with distraction. At the difficult to access posterocentral region (L50) of the talus, the PM approach without and with distraction allowed 26.7% (SD = 4.1) and 38.6% (SD = 5.6, P < 0.001) sagittal plane access compared with 18.7% (SD = 5.61, P = 0.03) and 27.5% (SD = 7.11, P = 0.003) through a PL approach.
The PM approach provides greater access to the posterocentral and PM talus. Using an external fixator for distraction can improve intraoperative visualization by at least 40%. This study provides a roadmap that can help guide talar dome surgical access for treatment of posterior talus fractures and help determine when an approach that includes an osteotomy can be avoided.
评估 2 种标准后入路（后内侧[PM]和后外侧[PL]）在有无牵开情况下，对距骨穹窿的可触及区域。
通过 12 个膝下截断的尸体下肢（6 对匹配），分别在 PM 或 PL 标准入路中进行有无外固定器牵开操作。在微计算机断层扫描（microCT）扫描仪中描绘并成像距骨穹窿的可触及区域，以实现可触及表面积的 3D 重建。研究结果为（1）总表面积和（2）距骨穹窿在预定间隔处矢状面距离的距骨穹窿可触及表面积。
PM 入路与 PL 入路相比，在有无牵开的情况下，都能显著提供更多的距骨穹窿触及区域（P < 0.001）。PM 入路在无牵开的情况下可触及距骨穹窿的 15.8%（SD = 4.7），在牵开的情况下可触及距骨穹窿的 26.4%（SD = 8.0，P < 0.001）。PL 入路在无牵开的情况下提供 6.69%（SD = 2.69，与 PM 相比 P = 0.006）和牵开的情况下提供 14.6%（SD = 6.24，与 PM 相比 P = 0.006）的距骨穹窿表面区域触及。在距骨的难以触及的后中心区域（L50），PM 入路在无牵开和牵开的情况下，矢状面可触及的分别为 26.7%（SD = 4.1）和 38.6%（SD = 5.6，P < 0.001），而通过 PL 入路则分别为 18.7%（SD = 5.61，P = 0.03）和 27.5%（SD = 7.11，P = 0.003）。
PM 入路可提供更大的后内侧和 PM 距骨触及区域。使用外固定器牵开可至少提高 40%的术中可视化效果。本研究提供了一张路线图，可以帮助指导距骨穹窿手术入路治疗后距骨骨折，并有助于确定何时可以避免包括截骨术的入路。
