Lutz Bernd, Kappe Thomas, Reichel Heiko, Taurman Rita
Department for Orthopaedic Surgery, University of Ulm, Ulm, Germany.
Department for Orthopaedic Surgery, University of Ulm, Ulm, Germany.
Foot Ankle Surg. 2022 Dec;28(8):1411-1414. doi: 10.1016/j.fas.2022.08.002. Epub 2022 Aug 4.
To reduce the rate of correction loss in hallux valgus surgery, a proximal to distal phalangeal articular angle (PDPAA) of the proximal phalanx of the greater toe of> 8° is considered an indication for a combined Akin and Chevron osteotomy. The PDPAA is measured between the articular surfaces of the proximal phalanx of the greater toe. Viewed from a sagittal perspective, the joint surfaces are not perpendicular aligned to the phalanx axis. Therefore, the PDPAA might be confounded by pronation. This study aims to, first, evaluate the intra- and interobserver reliability of the PDPAA and, second, to analyze the correlation to first ray pronation.
In a consecutive series of 59 feet who underwent hallux valgus (HV) surgery, PDPAA, round sign and other angles were measured on weight-bearing radiographs pre- and postoperatively. After power analysis, the intraclass correlation coefficient (ICC) was used to calculate the intra- and interobserver reliability. The correlation of PDPAA with the round sign as well as angles defining the HV and the Hallux valgus interphalangeus (HVI) were evaluated.
The PDPAA showed an excellent intra- and interobserver reliability (ICC 0.92 and 0.89, p < 0.05). The round sign did not correlate significantly with the PDPAA (p = 0.51). However, the PDPAA showed a moderate correlation with the interphalangeal angle (r = 0.51, p < 0.05) and fair inversely with the intermetatarsal angle (r = -0.45, p < 0.05).
First, measurement of PDPAA is reliable. Second, PDPAA is not associated with first ray pronation, but a false low PDPAA is geometrically possible. A high PDPAA correlates with a relevant HVI and inversely correlates with the HV like the HVI. Hence, first ray pronation should be treated first and a remaining PDPAA of> 8° after intraoperatively reevaluation separately.
为降低拇外翻手术中矫正丢失率，将拇趾近节趾骨近端至远端的关节角（PDPAA）大于8°视为联合Akin截骨术和契形截骨术的指征。PDPAA是在拇趾近节趾骨的关节面之间测量的。从矢状面看，关节面与趾骨轴线并非垂直对齐。因此，PDPAA可能会受到旋前的影响。本研究旨在，首先，评估PDPAA在观察者内和观察者间的可靠性，其次，分析其与第一跖骨旋前的相关性。
在连续59例行拇外翻（HV）手术的足部病例中，在负重位X线片上测量术前和术后的PDPAA、圆形征及其他角度。经过功效分析后，使用组内相关系数（ICC）计算观察者内和观察者间的可靠性。评估PDPAA与圆形征以及定义HV和拇趾间关节外翻（HVI）的角度之间的相关性。
PDPAA在观察者内和观察者间均显示出极好的可靠性（ICC分别为0.92和0.89，p<0.05）。圆形征与PDPAA无显著相关性（p = 0.51）。然而，PDPAA与趾间角呈中度相关性（r = 0.51，p<0.05），与跖间角呈负相关（r = -0.45，p<0.05）。
首先，PDPAA的测量是可靠的。其次，PDPAA与第一跖骨旋前无关，但在几何上可能出现PDPAA假性降低。高PDPAA与相关的HVI相关，且与HV呈负相关，与HVI相似。因此，应首先治疗第一跖骨旋前，术中重新评估后，若PDPAA仍大于8°则需单独处理。
