Department of Orthopedics, Government Medical College, Thiruvananthapuram, India.
Department of Community Medicine, Government Medical College, Thiruvananthapuram, India.
Musculoskelet Surg. 2023 Sep;107(3):313-322. doi: 10.1007/s12306-022-00756-9. Epub 2022 Aug 20.
Our study aimed to compare the functional outcome of HTO performed via lateral closing wedge osteotomy and medial open wedge osteotomy followed up for a mean period of 6 years using Lysholm knee score. Secondary objective was to find out whether an achievement of 2°-6° of mechanical axis had a significant impact in the outcome and how the outliers of 2°-6° (177°-182° (straight knees) and greater than 186° (overcorrection) performed in the medium term and how patients who lost correction to more than - 3° (persistent varus) performed in the medium term.
This is a prospective observational study.
Sixty-two consecutive patients who had undergone HTO by a single surgeon from 2012 to 2015 were followed up. The final follow-up visit was from August 2019 to December 2019. Nine were lost to follow-up, and 53 presented for the follow-up visit. Case records were noted for the preoperative LKS scores, preoperative mechanical axis, ROM, and preoperative tibiofemoral angle. Post-operative mechanical axis in full-length weight bearing at 4 months was also noted. During the latest visit, patients underwent LKS scoring, full-length weight-bearing X-rays to assess mechanical axis, and assessment of tibiofemoral angle. The results were grouped into excellent, good, fair, and poor outcomes based on LKS scale. The mechanical axes attained at surgery and at the follow-up were grouped into less than 177° as varus, 177°-182° as straight 182°-186° as required correction, and more than 186° as overcorrection. Lysholm knee score was dichotomised using LKS 84 as the cut-off (LKS ≥ 84 high LKS; LKS 84 low LKS).
A total of 53 patients with a median age of 56 years (SD 4.23) were included in this study. There were 8 (15.1%) males and 45 (84.9%) females. The mean ± SD of BMI of patients was 28.10 ± 2.66 kg/m. Medial opening wedge osteotomy was performed in 27 (50.9%) cases, and lateral closing wedge osteotomy was performed in 26 (49.1%). Median duration between the time of surgery and the follow-up was 72 months (IQR 32.5). Preoperatively, the mean LKS score of the patients was 50.25 ± 12.43 (88.68% had poor score and 11.32% had fair score), and the mean mechanical axis of the knee was 172.54 ± 3.78 (all had varus deformity). The mean (SD) preoperative LKS score of the 53 participants before the surgery was 50.25 (12.43). Poor score was reported by 47 (88.68%) and fair score by 6 (11.32%) patients, respectively. At the time of final follow-up, the mean (SD) LKS score of 53 patients was 77.81(17.11). At the time of final follow-up (when compared with the score before surgery), 41(77.36%) patients had improvement in the LKS score, 10 (18.87%) patients had no improvement in the score, and 2 (3.77%) patients worsened from fair to poor. The difference between the LKS score before surgery and at the final follow-up was significantly greater for patients who underwent medial opening wedge osteotomy [median (IQR)35 (26-38)] than for the patients who underwent lateral closing wedge osteotomy [median (IQR) 30 (23-34)], U226.5, p 0.026. Knees with desired valgus angle within 2°-6° and knees which remained straight at the final follow-up showed a good or excellent outcome at the final follow-up (23 out of 53 knees). Those knees with had varus HKA axis had a poor or fair outcome at the final follow-up (23 out of 53 knees). Those knees that were overcorrected also had poor outcomes.
Our study shows that both medial open wedge osteotomy and lateral closing wedge osteotomy are capable of improving knee function in medial compartment osteoarthritis of knee. Medial open wedge with locking plates is a biomechanically more stable construct compared with lateral closing wedge osteotomy. Irrespective of the two techniques chosen, the aim of the osteotomy should be to achieve an overcorrection of 2°-6° of valgus or at least to keep the knee straight (normal mechanical axis). This will give a satisfactory medium-term result. However, varus alignment and valgus alignment of more than 6° can result in a deterioration of function of knee. The results of the osteotomy are found to deteriorate with obesity, severe varus in preop mechanical axis and longer duration of follow-up.
我们的研究旨在比较通过外侧闭合楔形截骨术和内侧开放楔形截骨术进行 HTO 的功能结果，随访时间平均为 6 年，使用 Lysholm 膝关节评分进行评估。次要目标是确定机械轴的 2°-6°的实现是否对结果有显著影响，以及 2°-6°（177°-182°（直膝）和大于 186°（过度矫正））的异常值在中期的表现如何，以及在中期内丢失超过 -3°（持续内翻）的患者表现如何。
这是一项前瞻性观察研究。
对 2012 年至 2015 年间由一位外科医生进行的 HTO 的 62 例连续患者进行了随访。最终随访时间为 2019 年 8 月至 2019 年 12 月。有 9 例患者失访，53 例患者接受了随访。记录病例的术前 Lysholm 膝关节评分、术前机械轴、ROM 和术前胫股角。还记录了术后 4 个月全长负重时的术后机械轴。在最近的就诊时，患者接受了 Lysholm 膝关节评分、全长负重 X 线检查以评估机械轴，并评估胫股角。结果根据 Lysholm 量表分为优秀、良好、中等和差。手术和随访时获得的机械轴分为小于 177°为内翻、177°-182°为直、182°-186°为所需矫正，以及大于 186°为过度矫正。Lysholm 膝关节评分使用 LKS 84 作为截止值（LKS≥84 为高 LKS；LKS 84 为低 LKS）进行二分法。
共有 53 名中位年龄为 56 岁（SD 4.23）的患者纳入本研究。8 名（15.1%）为男性，45 名（84.9%）为女性。患者的 BMI 均值±SD 为 28.10±2.66kg/m。27 例（50.9%）行内侧开放楔形截骨术，26 例（49.1%）行外侧闭合楔形截骨术。手术与随访之间的中位时间间隔为 72 个月（IQR 32.5）。术前，患者的平均 Lysholm 膝关节评分（LKS）为 50.25±12.43（88.68%为差评分，11.32%为良评分），膝关节的平均机械轴为 172.54±3.78（均为内翻畸形）。53 名参与者术前 LKS 评分的平均值（SD）为 50.25（12.43）。47 例（88.68%）报告差评分，6 例（11.32%）报告良评分。在最后一次随访时，53 名患者的平均（SD）LKS 评分为 77.81（17.11）。与术前相比，41 名（77.36%）患者的 LKS 评分有所改善，10 名（18.87%）患者的评分没有改善，2 名（3.77%）患者的评分从良变为差。接受内侧开放楔形截骨术的患者的 LKS 评分变化（中位数（IQR）35（26-38））与接受外侧闭合楔形截骨术的患者（中位数（IQR）30（23-34））相比，差异有统计学意义，U226.5，p0.026。在最终随访时，机械轴在 2°-6°范围内保持直膝或保持直膝的膝关节（53 个膝关节中的 23 个）具有良好或优秀的最终随访结果。那些具有内翻 HKA 轴的膝关节在最终随访时具有差或良的结果（53 个膝关节中的 23 个）。那些过度矫正的膝关节也有较差的结果。
我们的研究表明，内侧开放楔形截骨术和外侧闭合楔形截骨术都能改善膝关节内侧间室骨关节炎患者的膝关节功能。与外侧闭合楔形截骨术相比，内侧开放楔形截骨术加锁定钢板是一种更稳定的生物力学结构。无论选择哪种技术，截骨术的目的都应该是实现 2°-6°的外翻或至少保持膝关节直（正常机械轴）。这将带来令人满意的中期结果。然而，内翻和外翻超过 6°会导致膝关节功能恶化。随着肥胖、术前机械轴的严重内翻和随访时间的延长，截骨术的结果会恶化。
