Department of Orthopaedic Surgery, Graduate School of Medicine, Kobe University, Kobe, Japan.
Department of Orthopaedic Surgery, Meiwa Hospital, Kobe, Japan.
Am J Sports Med. 2018 Apr;46(5):1150-1157. doi: 10.1177/0363546517752667. Epub 2018 Feb 21.
A fluoroscopic guidance method for medial patellofemoral ligament (MPFL) reconstruction has been widely used to determine the anatomic femoral attachment site.
To examine the graft length change patterns in MPFL reconstruction with a fluoroscopic guidance method.
Cross-sectional study; Level of evidence, 3.
Forty-four knees of 42 patients who underwent MPFL reconstruction for the treatment of recurrent patellar dislocation were examined prospectively. During surgery, suture anchors were inserted into the proximal one-third and center of the patella. A guide pin for the femoral tunnel was inserted into the position reported by Schöttle et al based on the true lateral view of the knee under fluoroscopic control. Changes in graft length patterns of the proximal and center anchors were examined through 0° to 120° of knee flexion. Favorable changes in length patterns were defined as meeting 2 of 3 criteria: (1) not long during flexion (≤3 mm between 30° and 120° of flexion) and either (2) nearly isometric during flexion between 0° and 90° or (3) slightly long during maximum extension (≤3 mm). Other patterns were considered unfavorable. If the change in length pattern was unfavorable, then the pin for the femoral tunnel was moved to different positions until it was favorable. Knees were separated into the favorable group and the unfavorable group. Differences between the groups regarding radiographic parameters were assessed. Student t test or chi-square test was used for statistical analysis.
Of the 44 knees, 31 (70.5%) showed favorable patterns. However, 13 knees (29.5%) showed unfavorable patterns; therefore, the position of the pin was changed. The mean ± SD distance from the original position to the final position was 5.3 ± 1.1 mm distal for 7 patients and 5.2 ± 0.4 mm posterodistal for 6 patients. Technical errors, including a nontrue lateral view and the tip of the wire not being in the determined area, were found for 4 of 13 knees in the unfavorable group. There was no statistical difference in radiographic parameters between the groups.
The graft length change pattern could be nonphysiologic at the position determined through the fluoroscopic guidance method; thus, caution may be necessary. The change in length pattern should be checked before graft fixation. If the length change pattern is unfavorable, then it is advisable to move it approximately 5 to 7 mm distally or posterodistally from the first position.
一种用于内侧髌股韧带（MPFL）重建的透视引导方法已被广泛用于确定解剖学股骨附着点。
研究透视引导下 MPFL 重建的移植物长度变化模式。
横截面研究；证据水平，3 级。
前瞻性检查 42 名 44 例接受 MPFL 重建治疗复发性髌骨脱位的患者的 44 个膝关节。手术中，缝线锚钉分别被植入髌骨近端三分之一和中心部位。在透视控制下的真正侧位 X 线片上，根据 Schöttle 等人的报告，将导针插入股骨隧道的位置。通过膝关节 0°至 120°的屈伸运动，检查近端和中心锚钉的移植物长度变化模式。如果满足以下 3 个标准中的 2 个，则认为长度变化模式良好：（1）在屈伸过程中不延长（屈伸 30°至 120°时长度变化不超过 3mm），或者（2）在 0°至 90°屈伸过程中几乎等长，或者（3）在最大伸展时略微延长（长度变化不超过 3mm）。否则，被认为是不良模式。如果长度变化模式不佳，则将股骨隧道的导针移动到不同位置，直到达到良好模式。将膝关节分为良好组和不良组。评估两组之间的影像学参数差异。采用 Student t 检验或卡方检验进行统计学分析。
44 个膝关节中，31 个（70.5%）表现为良好模式。然而，13 个膝关节（29.5%）表现为不良模式，因此，导针位置发生了改变。7 例患者的导针从初始位置向最终位置移动的距离平均为 5.3 ± 1.1mm 远侧，6 例患者的导针平均为 5.2 ± 0.4mm 远后侧。不良组中有 4 例（13 例中的 4 例）出现透视引导方法确定的位置存在技术误差，包括非真正侧位和导丝尖端不在确定区域内。两组间影像学参数无统计学差异。
透视引导方法确定的位置移植物长度变化模式可能是非生理性的，因此需要谨慎。在固定移植物之前，应检查移植物长度变化模式。如果长度变化模式不佳，建议从初始位置向远侧或远后侧移动约 5 至 7mm。
