Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN.
Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA.
J Hand Surg Am. 2024 Nov;49(11):1136.e1-1136.e9. doi: 10.1016/j.jhsa.2023.01.021. Epub 2023 Mar 16.
Transverse deficiency (TD) and symbrachydactyly may be difficult to distinguish due to shared phenotypes and a lack of pathognomonic features. The 2020 Oberg-Manske-Tonkin classification update modified these anomalies to include "with ectodermal elements" for symbrachydactyly and "without ectodermal elements" for TD as a defining differentiating characteristic. The purpose of this investigation was to characterize ectodermal elements and the level of deficiency and to examine whether ectodermal elements versus the level of deficiency was a greater determining factor for Congenital Upper Limb Differences (CoULD) surgeons making the diagnosis.
This was a retrospective review of 254 extremities from the CoULD registry with a diagnosis of symbrachydactyly or TD by pediatric hand surgeons. Ectodermal elements and the level of deficiency were characterized. A review of the registry radiographs and photographs was used to classify the diagnosis and compare it with the diagnosis given by the pediatric hand surgeons. The presence/absence of nubbins versus the level of deficiency as the determining factor to differentiate the pediatric hand surgeons' diagnosis of symbrachydactyly (with nubbins) versus TD (without nubbins) was analyzed.
Based on radiographs and photographs of the 254 extremities, 66% had nubbins on the distal end of the limb; of the limbs with nubbins, nails were present on 51%. The level of deficiency was amelia/humeral (n = 9), <1/3 transverse forearm (n = 23), 1/3 to 2/3 transverse forearm (n = 27), 2/3 to full forearm TD (n = 38), and metacarpal/phalangeal (n = 103). The presence of nubbins was associated with a four times higher likelihood of a pediatric hand surgeon's diagnosis of symbrachydactyly. However, a distal deficiency is associated with a 20-times higher likelihood of a diagnosis of symbrachydactyly than a proximal deficiency.
Although both the level of deficiency and ectodermal elements are important, the level of deficiency was a greater determining factor for a diagnosis of symbrachydactyly versus TD. Our results suggest that the level of deficiency and nubbins should both be described to help provide greater clarity in the diagnosis of symbrachydactyly versus TD.
TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.
由于横断性缺陷（TD）和并指畸形具有相似的表型，且缺乏特征性表现，因此两者较难鉴别。2020 年 Oberg-Manske-Tonkin 分类更新将这些异常修改为“伴外胚层成分”用于并指畸形，“不伴外胚层成分”用于 TD，作为明确的鉴别特征。本研究旨在描述外胚层成分和缺失程度，并探讨外胚层成分与缺失程度哪个对先天性上肢差异（CoULD）外科医生做出诊断的影响更大。
这是一项对 CoULD 注册中心 254 例由小儿手外科医生诊断为并指畸形或 TD 的上肢进行的回顾性研究。对其外胚层成分和缺失程度进行了描述。通过回顾注册中心的 X 线片和照片，对诊断结果进行分类，并与小儿手外科医生的诊断结果进行比较。分析有无小芽作为鉴别小儿手外科医生诊断的并指畸形（伴小芽）与 TD（无小芽）的决定因素。
根据 254 例肢体的 X 线片和照片，66%的肢体末端有小芽；有小芽的肢体中，51%有指甲。缺失程度为：肱骨/尺桡骨缺失（n=9）、<1/3 前臂横断（n=23）、1/3-2/3 前臂横断（n=27）、2/3-全前臂 TD（n=38）和掌骨/指骨缺失（n=103）。存在小芽使小儿手外科医生诊断为并指畸形的可能性增加四倍。然而，与近端缺失相比，远端缺失与诊断为并指畸形的可能性增加 20 倍有关。
虽然缺失程度和外胚层成分都很重要，但缺失程度是小儿手外科医生诊断为并指畸形与 TD 的更重要的决定因素。我们的研究结果表明，应同时描述缺失程度和小芽，以帮助在并指畸形与 TD 的诊断中提供更明确的信息。
研究类型/证据水平：诊断 IV 级。
