Open-Wedge HTO with Absorbable β-TCP/PLGA Spacer Implantation and Proximal Fibular Osteotomy for Medial Compartmental Knee Osteoarthritis: New Technique Presentation

The purpose of this study was to present a new absorbable spacer for medial compartmental knee osteoarthritis (OA). The functional and radiographic results of patients treated with the novel surgical technique were also evaluated to investigate its clinical feasibility. Patients with medial compartmental knee OA who underwent open-wedge high tibial osteotomy (HTO) with absorbable β-TCP/PLGA [30% beta-tricalcium phosphate and 70% poly (lactic-co-glycolic acid)] spacer implantation and proximal fibular osteotomy from January 2016 to February 2017 were retrospectively analyzed. The operation time, blood loss, and relevant complications were reviewed. The femorotibial angle (FTA), varus angle (VA), joint line convergence angle (JLCA), American Knee Society Score (KSS), and visual analog scale (VAS) score were recorded preoperatively and at the final follow-up, respectively. At the final follow-up, the mean FTA and JLCA were 179.85° ± 4.34° and 2.44° ± 1.26°, respectively, which were smaller than the preoperative values (182.94° ± 3.86° and 4.12° ± 1.65°, respectively; both <i>p</i> &lt; 0.001). The final VA and VAS score were lower than those measured preoperatively (both <i>p</i> &lt; 0.001). The clinical and functional KSSs at the final follow-up were higher than the preoperative scores (<i>p</i> &lt; 0.001). This novel absorbable spacer could provide adequate stability for the tibial osteotomy gap, at a lower cost than a traditional plate. With the use of this spacer as an osteoinductive and biodegradable device, secondary surgery for fixation removal could be avoided. The novel surgical technique could improve both the radiographic appearance and the function of the knee in patients with knee OA.

本研究旨在为膝关节内侧间室骨关节炎（OA）患者介绍一款新型可吸收间隔器，并评估采用该新型手术方式治疗患者的功能结局与影像学表现，以探究其临床可行性。本研究回顾性分析了2016年1月至2017年2月期间，接受开放式楔形高位胫骨截骨术（HTO）联合可吸收β-磷酸三钙（β-TCP）/聚乳酸-羟基乙酸共聚物（PLGA）间隔器植入（该间隔器由30%β-磷酸三钙与70%聚（乳酸-羟基乙酸共聚物）构成）并行腓骨近端截骨术的内侧间室膝骨关节炎患者的临床资料，记录患者的手术时长、失血量及相关并发症情况。分别于术前及末次随访时，记录股胫角（FTA）、内翻角（VA）、关节线会聚角（JLCA）、美国膝关节协会评分（KSS）及视觉模拟评分（VAS）。末次随访时，患者的平均股胫角（FTA）与关节线会聚角（JLCA）分别为179.85°±4.34°与2.44°±1.26°，均低于术前的182.94°±3.86°与4.12°±1.65°（均p<0.001）；末次随访时的内翻角（VA）与视觉模拟评分（VAS）亦显著低于术前水平（均p<0.001）；末次随访时的临床与功能KSS评分均高于术前水平（p<0.001）。该新型可吸收间隔器可为胫骨截骨间隙提供足够的稳定性，且成本低于传统钢板；作为骨诱导性可降解装置，使用该间隔器可避免二次手术取出内固定物。该新型手术方式可同时改善膝骨关节炎患者的影像学表现与膝关节功能。