Amaro Joicemar Tarouco, Astur Diego Costa, Kaleka Camila Cohen, Debieux Pedro, Costa José Ricardo Dantas Moura, da Silva Gustavo Montibeller, Oliveira Filho Nilton Gomes, Cohen Moisés
Hospital Israelita Albert Einstein, São Paulo, Brazil.
São Paulo Federal University, São Paulo, Brazil.
J ISAKOS. 2025 Feb;10:100341. doi: 10.1016/j.jisako.2024.100341. Epub 2024 Nov 20.
To investigate the causes of failure in unicompartmental knee arthroplasty (UKA), types of implants used in the revision, evaluate the need to use tibial stems, metal block augmentations, and bone grafts during conversion to total knee arthroplasty (TKA).
In a 10-year retrospective analysis, focussing on cases of UKA failure, our study aimed to categorise early and late failures, determine the primary failure modes and assess the utilisation of bone augmentations and grafts during conversion to TKA. We evaluated patient data, diagnoses, procedure intervals, and follow-up periods to provide a comprehensive understanding of the conversion process.
During the past decade, 301 UKA procedures were performed, with 36 knees (11.96%) requiring conversion to TKA. Patient ages averaged 64.3 years, with varied diagnoses, including osteoarthritis and avascular necrosis. The most common failure mode was component loosening or sinking (52.78%), followed by progression of arthritis (25%). Of the 31 cases with mobile-bearing UKA, 9 (29.03%) developed instability and displacement of the polyethylene. Of the 36 cases converted from UKA to TKA, in 31 (86.11%) a revision tibial component with a tibial stem was used. Metal block augmentation was performed in 19 knees (52,78%). All revised UKAs were converted to cemented TKA, with a focus on addressing tibial side issues, which constituted 72.22% of the revisions.
This study highlights the challenges associated with UKA failure, particularly early failures linked to displaced bearings. Converting from UKA to TKA presents technical hurdles, including rod alignment and utilisation. Management of proximal tibial defects with metal block augmentation proving to be a viable approach. The use of modular metal augmentation simplifies the reconstruction process. Although the study has limitations, it contributes valuable information about the complexities of knee arthroplasty conversion.
Therapeutic study, level IV (case series).
探讨单髁膝关节置换术（UKA）失败的原因、翻修时使用的植入物类型，评估在转换为全膝关节置换术（TKA）过程中使用胫骨柄、金属垫块和骨移植的必要性。
在一项为期10年的回顾性分析中，我们的研究聚焦于UKA失败病例，旨在对早期和晚期失败进行分类，确定主要失败模式，并评估转换为TKA过程中骨增强材料和移植骨的使用情况。我们评估了患者数据、诊断、手术间隔和随访期，以全面了解转换过程。
在过去十年中，共进行了301例UKA手术，其中36例膝关节（11.96%）需要转换为TKA。患者平均年龄为64.3岁，诊断多样，包括骨关节炎和缺血性坏死。最常见的失败模式是假体松动或下沉（52.78%），其次是关节炎进展（25%）。在31例使用活动平台UKA的病例中，9例（29.03%）出现聚乙烯不稳定和移位。在从UKA转换为TKA的36例病例中，31例（86.11%）使用了带胫骨柄的翻修胫骨假体。19例膝关节（52.78%）进行了金属垫块增强。所有翻修的UKA均转换为骨水泥型TKA，重点解决胫骨侧问题，占翻修病例的72.22%。
本研究强调了UKA失败相关的挑战，特别是与移位轴承相关的早期失败。从UKA转换为TKA存在技术障碍，包括杆的对齐和使用。用金属垫块增强处理胫骨近端缺损被证明是一种可行的方法。模块化金属增强的使用简化了重建过程。尽管本研究有局限性，但它为膝关节置换术转换的复杂性提供了有价值的信息。
治疗性研究，IV级（病例系列）。
