From the Orthopaedic Oncology Service, Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA (Dr. Yeung, Dr. Lans, Dr. Kuechle, Wright, and Dr. Lozano-Calderón), and the Division of Musculoskeletal Radiology, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (Dr. Chang).
J Am Acad Orthop Surg Glob Res Rev. 2020 May;4(5):e2000062. doi: 10.5435/JAAOSGlobal-D-20-00062.
Elbow prosthetic reconstruction after distal humeral tumor resection is challenging. We identify the value of the proximal ulna dorsal angulation (PUDA) as an easily-measured radiographic parameter that can help inform ulnar component sizing in the Solar Elbow System (SES) and the Modular Universal Tumor and Revision System (MUTARS), two modular prosthetic systems that are commonly used after tumor resection in this anatomic location. We hypothesized that a larger PUDA measurement would require smaller ulnar stems.
Demographic data and PUDA measurements were retrospectively reviewed for 514 patients. Multivariate regression was used to determine the effects of patient demographic data on the PUDA. PUDA measurements were collected by three independent reviewers on lateral elbow radiographs. MUTARS and SES templating software was then used to validate the relationship between the PUDA and ulnar stem sizing.
Regression analysis showed no substantial contribution of demographic variables to the PUDA measurement (adjusted R2 = 0.02, F(6, 508) = 2.704, P = 0.01). The MUTARS implant fit 97% of elbows with a PUDA <5° and 91.6% of elbows with PUDA ≥5° (P = 0.26). The largest SES combination fit 100% of elbows with a PUDA ≤10° versus 93% of elbows with a PUDA >10° (P = 0.029). Elbows accommodating the largest SES combination had a smaller median PUDA (5.4° versus 11.7°, P = 0.034); elbows accommodating the MUTARS implant had a smaller median PUDA (5.4° versus 5.8°, P = 0.34).
The PUDA is a valuable and easily used preoperative planning tool for prosthetic elbow reconstruction after tumor resection. The proximal ulna dorsal angulation can be easily measured to predict ulnar component fit and reduce intraoperative complications. In patients with a PUDA ≥5°, ulnar component stem fit for current systems may be more challenging.
肱骨远端肿瘤切除后进行肘部假体重建具有挑战性。我们确定了尺骨近端背侧成角（PUDA）作为一个易于测量的放射学参数的价值，该参数可以帮助确定在 Solar 肘部系统（SES）和模块化通用肿瘤和修复系统（MUTARS）中使用的尺骨组件尺寸，这两种模块化假体系统常用于该解剖部位的肿瘤切除后。我们假设较大的 PUDA 测量值需要较小的尺骨干。
回顾性分析了 514 例患者的人口统计学数据和 PUDA 测量值。使用多元回归来确定患者人口统计学数据对 PUDA 的影响。PUDA 测量值由三位独立的观察者在肘部侧位 X 光片上收集。然后，使用 MUTARS 和 SES 模板软件验证了 PUDA 与尺骨干尺寸之间的关系。
回归分析显示，人口统计学变量对 PUDA 测量值没有实质性贡献（调整 R2 = 0.02，F(6, 508) = 2.704，P = 0.01）。MUTARS 植入物适合 97%的 PUDA<5°和 91.6%的 PUDA≥5°（P = 0.26）。最大的 SES 组合适合 100%的 PUDA≤10°与 93%的 PUDA>10°（P = 0.029）。可容纳最大 SES 组合的肘部有较小的中位数 PUDA（5.4°与 11.7°，P = 0.034）；可容纳 MUTARS 植入物的肘部有较小的中位数 PUDA（5.4°与 5.8°，P = 0.34）。
PUDA 是一种有价值且易于使用的术前规划工具，可用于肿瘤切除后肘部假体重建。尺骨近端背侧成角可轻松测量，以预测尺骨组件的贴合度，减少术中并发症。在 PUDA≥5°的患者中，当前系统的尺骨组件干适配可能更具挑战性。
