Department of Joint Surgery, Honghui Hospital, Xi'an Jiao Tong University, Xi'an, Shaan Xi, China.
Department of Orthopedics, Xiangya Hospital Central South University, No. 87 Xiangya Road, Kaifu District, Changsha City, 410008, Hunan, China.
J Orthop Surg Res. 2023 Jan 27;18(1):65. doi: 10.1186/s13018-023-03530-0.
Severe knee valgus/varus or complex multiplanar deformities are common in clinic. If not corrected in time, cartilage wear will be aggravated and initiate the osteoarthritis due to lower limb malalignment. Internal fixation is unable to correct severe complex deformities, especially when combined with lower limb discrepancy (LLD). Based on the self-designed digital six-axis external fixator Q spatial fixator (QSF), which can correct complex multiplanar deformities without changing structures, accuracy of correction can be improved significantly.
This retrospective study included 24 patients who suffered from complex knee deformity with LLD treated by QSF and internal fixation at our institution from January 2018 to February 2021. All patients had a closing wedge distal femoral osteotomy with internal fixation for immediate correction and high tibia osteotomy with QSF fixation for postoperative progressive correction. Data of correction prescriptions were computed by software from postoperative CT scans.
Mean discrepancy length of operative side was 2.39 ± 1.04 cm (range 0.9-4.4 cm) preoperatively. The mean difference of lower limb was 0.32 ± 0.13 cm (range 0.11-0.58 cm) postoperatively. The length of limb correction had significant difference (p < 0.05). The mean MAD and HKA decreased significantly (p < 0.05), and the mean MPTA and LDFA increased significantly (p < 0.05). There were significant increase (p < 0.05) in the AKSS-O, AKSS-F and Tegner Activity Score. The lower limb alignment was corrected (p < 0.05). The mean time of removing external fixator was 112.8 ± 17.9 days (range 83-147 days).
Complex knee deformity with LLD can be treated by six-axis external fixator with internal fixation without total knee arthroplasty. Lower limb malalignment and discrepancy can be corrected precisely and effectively by this approach.
严重的膝内翻/外翻或复杂的多平面畸形在临床上很常见。如果不及时纠正，软骨磨损会加剧，并因下肢对线不良而引发骨关节炎。内固定无法纠正严重的复杂畸形，尤其是合并下肢不等长（LLD）时。基于自主设计的数字六轴外固定器 Q 空间固定器（QSF），它可以在不改变结构的情况下纠正复杂的多平面畸形，从而显著提高矫正精度。
本回顾性研究纳入了 2018 年 1 月至 2021 年 2 月期间我院收治的 24 例复杂膝关节畸形伴 LLD 患者，均接受 QSF 联合内固定治疗。所有患者均接受闭合楔形股骨远端截骨内固定以即刻矫正，胫骨高位截骨联合 QSF 固定以术后进行渐进性矫正。通过术后 CT 扫描的软件计算矫正方案的数据。
术前手术侧的平均差异长度为 2.39±1.04cm（范围 0.9-4.4cm）。术后下肢平均差值为 0.32±0.13cm（范围 0.11-0.58cm）。肢体矫正长度有显著差异（p<0.05）。MAD 和 HKA 明显降低（p<0.05），MPTA 和 LDFA 明显升高（p<0.05）。AKSS-O、AKSS-F 和 Tegner 活动评分均有显著升高（p<0.05）。下肢对线得到纠正（p<0.05）。外固定器去除的平均时间为 112.8±17.9 天（范围 83-147 天）。
复杂膝内翻/外翻畸形伴 LLD 可采用内固定的六轴外固定器治疗，无需全膝关节置换。通过这种方法可以精确有效地矫正下肢对线不良和差异。
