Lyon-Ortho-Clinic, Clinique de la Sauvegarde, Ramsay Santé, Lyon, France.
ReSurg SA, Nyon, Switzerland.
Am J Sports Med. 2023 Jul;51(8):2091-2097. doi: 10.1177/03635465231175879. Epub 2023 May 30.
Tibial deflexion osteotomy (TDO) is sometimes indicated for revision anterior cruciate ligament (ACL) reconstruction in knees with posterior tibial slope (PTS) ≥12° and aims to decrease PTS to around 5°. When planning TDO, measuring the anterior tibial metaphyseal height (aHt) could help ascertain whether the available metaphyseal bone would be sufficient to create the wedge and leave adequate residual bone.
To (1) determine whether, compared with knees with normal native PTS (<12°), aHt is greater in knees with excessive native PTS (≥12°), and (2) verify if, aiming to decrease PTS to 5°, supratuberosity TDO in knees with excessive native PTS could be performed without tibial tuberosity osteotomy, leaving a minimum of 15 mm of residual bone for fixation staples or plates.
Cross-sectional study; Level of evidence, 3.
True lateral radiographs of 350 consecutive patients scheduled for ACL reconstruction were digitized to measure PTS, tibial medial plateau length, tibial anterior and posterior metaphyseal heights and inclinations, and patellar height. Measurements were compared between knees with PTS <12° and those with ≥12°. The wedge height required for supratuberosity TDO was estimated for knees with excessive PTS, aiming for a target PTS of 5°, to determine the proportion of knees that would have residual aHt <15 mm.
A total of 326 knees had adequate true lateral radiographs. The mean PTS was 9.8°± 3.1° (range, 1°-20°) and exceeded 12° in 83 (25%) knees. There were no significant differences between knees with normal versus excessive PTS when comparing aHt (30.7 ± 4.5 mm vs 31.6 ± 4.9 mm; = .270) and medial tibial plateau length (43.1 ± 5.4 mm vs 43.3 ± 5.6 mm; = .910). Setting the target mPTS at 5° for supratuberosity TDO, the mean residual aHt was 25.0 ± 4.4 mm, and 7 (8%) knees had a residual aHt <20 mm, of which only 1 (1%) had residual aHt <15 mm. Setting the target mPTS at 0°, the mean residual aHt was 21.3 ± 4.2 mm, and 36 (43%) knees had a residual aHt <20 mm, of which only 4 (5%) had residual aHt <15 mm.
aHt was not significantly different between knees with normal versus excessive PTS. Estimation of the wedge height required for supratuberosity TDO to reduce excessive PTS to 5° revealed sufficient metaphyseal bone for wedge removal in all knees. Furthermore, 99% of knees would have sufficient residual bone (aHt, ≥15 mm) to accommodate fixation staples or plates, without the need for tibial tuberosity osteotomy.
胫骨后倾截骨术（TDO）有时用于治疗胫骨后斜率（PTS）≥12°的前交叉韧带（ACL）重建翻修膝关节，目的是将 PTS 降低到约 5°。在规划 TDO 时，测量胫骨前骨干骺端高度（aHt）可以帮助确定是否有足够的骺骨来制造楔形并留下足够的残余骨。
（1）确定与 PTS 正常（<12°）的膝关节相比，PTS 过大（≥12°）的膝关节中 aHt 是否更大；（2）验证在 PTS 过大的膝关节中，为将 PTS 降低到 5°，是否可以进行髌上突 TDO 而无需胫骨结节截骨术，从而为固定钉或板留下至少 15mm 的残余骨。
横断面研究；证据水平，3 级。
对 350 例连续拟行 ACL 重建的患者的标准侧位 X 线片进行数字化，以测量 PTS、胫骨内侧平台长度、胫骨前、后骨干骺端高度和倾斜度以及髌骨高度。比较 PTS<12°和 PTS≥12°的膝关节之间的测量值。为 PTS 过大的膝关节估计髌上突 TDO 所需的楔形高度，目标 PTS 为 5°，以确定有多少膝关节的残余 aHt<15mm。
共有 326 例膝关节具有足够的标准侧位 X 线片。平均 PTS 为 9.8°±3.1°（范围，1°-20°），83 例（25%）膝关节 PTS 超过 12°。与 PTS 正常的膝关节相比，PTS 过大的膝关节的 aHt（30.7±4.5mm 与 31.6±4.9mm； =.270）和胫骨内侧平台长度（43.1±5.4mm 与 43.3±5.6mm； =.910）无显著差异。将髌上突 TDO 的目标 mPTS 设置为 5°时，平均残余 aHt 为 25.0±4.4mm，7（8%）例膝关节残余 aHt<20mm，其中仅 1（1%）例残余 aHt<15mm。将目标 mPTS 设置为 0°时，平均残余 aHt 为 21.3±4.2mm，36（43%）例膝关节残余 aHt<20mm，其中仅 4（5%）例残余 aHt<15mm。
PTS 正常与 PTS 过大的膝关节之间的 aHt 无显著差异。估计髌上突 TDO 所需的楔形高度以将 PTS 降低到 5°，显示所有膝关节均有足够的骺骨去除楔形。此外，99%的膝关节有足够的残余骨（aHt，≥15mm）来容纳固定钉或板，而无需胫骨结节截骨术。
