Soundarrajan Dhanasekaran, Kumar K Madhan, Singh Rithika, Rajasekaran Raja Bhaskara, Palanisami Dhanasekarararaja, Natesan Rajkumar, Rajasekaran Shanmuganathan
Ganga Hospital, Coimbatore, India.
Int Orthop. 2025 May 22. doi: 10.1007/s00264-025-06563-8.
Managing knee arthritis with an associated extra-articular deformity (EAD) by total knee arthroplasty (TKA) is technically demanding. Intra-articular correction of EAD often requires extensive soft tissue release, which can be challenging. This study evaluates whether imageless robotic assisted TKA facilitates intra-articular correction using functional alignment and desired under-correction of severe EAD. Additionally, we assess the short-term functional and radiological outcomes in these patients.
We prospectively reviewed 14 consecutive patients with knee osteoarthritis and angular EAD of the femur or tibia due to malunited fractures who underwent robotic-assisted TKA between November 2022 and April 2024. Ten patients had tibial EAD, and four had femoral EAD. Twelve had varus deformity and rest two had valgus deformity. Functional outcomes were assessed using the Oxford Knee Score (OKS), Knee Society Score (KSS), and Knee Society Functional Score (KSS-F). Radiological parameters included the Hip-Knee-Ankle (HKA) axis, mechanical axis deviation (MAD), the centre of rotation of angulation (CORA), medial proximal tibial angle (MPTA), and lateral distal femoral angle (LDFA).
The mean follow-up period was 16 months (range: 8 to 25 months). The mean EAD measured 13.8° (range: 5.1°-21.1°) in the coronal plane and 8.2° (range: 1.2°-22.8°) in the sagittal plane. The mean HKA angle improved from 163.9° ± 7.8° preoperatively to 176.4° ± 1.4° postoperatively (p < 0.05) for varus knees and from 189.5 ± 9.2° to 183.8 ± 2.6° for valgus knees (p = 0.002). No patients required grade IV soft tissue release or constrained prosthesis. The mean arc of motion improved from 94.6° ± 19.3° to 109.6° ± 9.8° (p = 0.001). The KSS, KSS-F, and OKS significantly improved from 25.1 ± 10.8, 36.4 ± 14.5, and 17.2 ± 5.7 preoperatively to 86.8 ± 4.4, 88.6 ± 5.3, and 41.4 ± 4.8 postoperatively (p < 0.001). No radiolucent lines were observed at the bone-cement interface during follow-up. Additionally, no complications such as infection, aseptic loosening, or ligament instability occurred.
Robotic-assisted TKA allows for effective intra-articular correction of severe EAD while minimizing the need for extensive soft tissue release. Robotic-assisted TKA helps in executing functional alignment, desired under-correction of the deformity and optimal soft tissue balance, resulting in satisfactory functional and radiological outcomes.
通过全膝关节置换术（TKA）治疗伴有关节外畸形（EAD）的膝关节炎在技术上具有挑战性。关节内矫正EAD通常需要广泛的软组织松解，这可能具有挑战性。本研究评估无图像机器人辅助TKA是否有助于利用功能对线和对严重EAD进行预期的欠矫正来进行关节内矫正。此外，我们评估这些患者的短期功能和放射学结果。
我们前瞻性地回顾了2022年11月至2024年4月期间连续接受机器人辅助TKA的14例因骨折畸形愈合导致膝骨关节炎和股骨或胫骨角状EAD的患者。10例患者有胫骨EAD，4例有股骨EAD。12例有内翻畸形，其余2例有外翻畸形。使用牛津膝关节评分（OKS）、膝关节协会评分（KSS）和膝关节协会功能评分（KSS-F）评估功能结果。放射学参数包括髋-膝-踝（HKA）轴、机械轴偏差（MAD）、成角旋转中心（CORA）、胫骨近端内侧角（MPTA）和股骨远端外侧角（LDFA）。
平均随访期为16个月（范围：8至25个月）。EAD在冠状面的平均角度为13.8°（范围：5.1°-21.1°），在矢状面为8.2°（范围：1.2°-22.8°）。内翻膝的平均HKA角从术前的163.9°±7.8°改善至术后的176.4°±1.4°（p＜0.05），外翻膝从189.5±9.2°改善至183.8±2.6°（p = 0.002）。没有患者需要IV级软组织松解或限制性假体。平均活动弧从94.6°±19.3°改善至109.6°±9.8°（p = 0.001）。KSS、KSS-F和OKS从术前的25.1±10.8、36.4±14.5和17.2±5.7显著改善至术后的86.8±4.4、88.6±5.3和41.4±4.8（p＜0.001）。随访期间在骨水泥界面未观察到透光线。此外，未发生感染、无菌性松动或韧带不稳定等并发症。
机器人辅助TKA能够有效进行关节内严重EAD的矫正，同时尽量减少广泛软组织松解需求。机器人辅助TKA有助于实现功能对线、对畸形进行预期的欠矫正以及最佳的软组织平衡，从而产生令人满意的功能和放射学结果。
