Frumberg David B, Naziri Qais, Pivec Robert, Bloom Lee, Freeman Barbara, Uribe Jaime A
Department of Orthopaedic Surgery and Rehabilitation Medicine, SUNY Downstate Medical Center/University Hospital Brooklyn, Brooklyn, New York 11203.
Department of Orthopaedic Surgery and Rehabilitation, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA.
J Long Term Eff Med Implants. 2018;28(1):41-46. doi: 10.1615/JLongTermEffMedImplants.2017020615.
The routine workup of hallux valgus includes measurements of the distal metatarsal articular angle (DMAA). However, this angle may not be a reliable measurement when rotational deformities occur. Eight matched cadaveric feet were evaluated radiographically using fluoroscopy. The intermetatarsal angle (IMA), hallux valgus angle, and DMAA were evaluated as a baseline. Then, we assessed whether axial rotation of 15°, 30°, 45°, and 60° affected the accuracy of the IMA and the DMAA significantly. Statistical evaluation was performed using Student's t tests and analysis of variance. The IMA remained stable for each anterior-posterior image despite rotation of the distal segment, with a mean difference of less than 2.5°. However, the DMAA was not constant, having different angles of rotation through the osteotomy site. We were able to demonstrate that measurement of the DMAA varies significantly with rotation of the distal first metatarsal. Using the DMAA to assess first metatarsophalangeal joint congruency should be done cautiously because it may estimate unreliably and inaccurately the 3D deformity often encountered in pathologic hallux valgus.
拇外翻的常规检查包括测量第一跖骨远端关节角（DMAA）。然而，当出现旋转畸形时，这个角度可能不是一个可靠的测量指标。使用荧光透视对八对匹配的尸体足进行影像学评估。测量跖间角（IMA）、拇外翻角和DMAA作为基线。然后，我们评估15°、30°、45°和60°的轴向旋转是否会显著影响IMA和DMAA测量的准确性。采用学生t检验和方差分析进行统计学评估。尽管远端节段发生旋转，但每个前后位图像的IMA保持稳定，平均差异小于2.5°。然而，DMAA并不恒定，在截骨部位有不同的旋转角度。我们能够证明，DMAA的测量值会随着第一跖骨远端的旋转而显著变化。使用DMAA评估第一跖趾关节的一致性时应谨慎，因为它可能会不可靠且不准确地估计病理性拇外翻中经常遇到的三维畸形。
