Rajgopal Ashok, Kumar Sumit, Aggarwal Kalpana
Institute of Musculoskeletal disorders and Orthopaedics, Medanta- The Medicity Hospital Gurugram, Haryana, India.
Arthroplast Today. 2021 Jan 11;7:76-83. doi: 10.1016/j.artd.2020.12.004. eCollection 2021 Feb.
Managing severe periarticular bone loss poses a major challenge in complex primary and revision total knee arthroplasty (TKA). Impaction bone graft, structural allografts, metal augments, and mega prosthesis are some of the methods used to address major bone loss. Tantalum metal (TM) Cones (Zimmer, Warsaw, IN) were introduced as an alternative to address this cohort of patients. The advantages of these cones include excellent biocompatibility, high porosity with osteoconductive potential, and a modulus of elasticity between cortical and cancellous bone. In addition, it is bioactive and offers an intrinsically high friction fit.
A cohort of 62 patients with severe distal femoral and proximal tibial bone loss were operated for primary and revision TKA between January 2007 and December 2014 and followed up for a mean period of 108.5 months (range: 60-156 months). Preoperative and postoperative range of motion and Knee Society score were documented. Postoperatively long leg X-rays were performed at each follow-up visit to determine osteointegration, evidence of loosening, and migration.
The range of motion and Knee Society score improved considerably from preoperative a value of 63.9 ± 13.9° and 52 ± 14.9 to 102.1 ± 9.9° and 76.1 ± 10.03, respectively, at the final follow-up visit in the primary cohort and 52.14 ± 13.3° and 38.1 ± 9.1 to 92 ± 8° and 68.5 ± 4.3, respectively, in the revision cohort. Serial radiographs demonstrated complete osteointegration of the TM cones at the final follow-up.
Our study demonstrates excellent midterm survivorship of TM cones with predictable osteointegration and good outcomes (clinical and radiological) in treatment of severe femoral and tibial metaphyseal bone defects in complex primary and revision TKAs.
在复杂的初次及翻修全膝关节置换术（TKA）中，处理严重的关节周围骨缺损是一项重大挑战。打压植骨、结构性同种异体骨移植、金属垫块及大型假体是用于解决严重骨缺损的一些方法。钽金属（TM）锥体（捷迈公司，印第安纳州华沙）被引入以应对这类患者群体。这些锥体的优点包括出色的生物相容性、具有骨传导潜力的高孔隙率以及介于皮质骨和松质骨之间的弹性模量。此外，它具有生物活性并提供内在的高摩擦配合。
2007年1月至2014年12月期间，对62例严重股骨远端和胫骨近端骨缺损患者进行了初次及翻修TKA手术，并平均随访108.5个月（范围：60 - 156个月）。记录术前及术后的活动范围和膝关节协会评分。术后每次随访时拍摄长腿X线片，以确定骨整合情况、松动迹象及移位情况。
在初次队列的最终随访中，活动范围和膝关节协会评分从术前的63.9±13.9°和52±14.9分别显著改善至102.1±9.9°和76.1±10.03；在翻修队列中，从术前的52.14±13.3°和38.1±9.1分别改善至92±8°和68.5±4.3。系列X线片显示在最终随访时TM锥体完全骨整合。
我们的研究表明，TM锥体在中期具有出色的生存率，在复杂的初次及翻修TKA中治疗严重的股骨和胫骨干骺端骨缺损时，具有可预测的骨整合及良好的临床和影像学效果。
