Yilmaz Müjgan, Holm Christina Enciso, Lind Thomas, Flivik Gunnar, Odgaard Anders, Petersen Michael Mørk
Department of Orthopedic Surgery, University Hospital of Copenhagen, Rigshospitalet, Inge Lehmanns Vej 6, 2100, Copenhagen Ø, Denmark.
Department of Orthopedic Surgery, University Hospital of Copenhagen, Herlev-Gentofte Hospital, Gentofte Hospitalsvej 1, 2900, Hellerup, Denmark.
Knee Surg Relat Res. 2021 Aug 17;33(1):25. doi: 10.1186/s43019-021-00111-5.
Aseptic loosening is one of the major reasons for late revision in total knee arthroplasty (TKA). The risk of aseptic loosening can be detected using radiostereometric analysis (RSA), whereby micromovements (migration) can be measured, and thus RSA is recommended in the phased introduction of orthopedic implants. Decrease in bone mineral density (BMD), as measured by dual-energy x ray absorptiometry (DXA), is related to the breaking strength of the bone, which is measured concurrently by RSA. The aim of the study was to evaluate bone remodeling and implant migration with cemented asymmetrical tibial and uncemented femoral components after TKA with a follow up period of 2 years.
This was a prospective longitudinal cohort study of 29 patients (number of female/male patients 17/12, mean age 65.2 years), received a hybrid Persona® TKA (Zimmer Biomet, Warsaw, IN, USA) consisting of a cemented tibial, an all-polyethylene patella, and uncemented trabecular metal femoral components. Follow up: preoperative, 1 week, and 3, 6, 12 and 24 months after surgery, and double examinations for RSA and DXA were performed at 12 months. RSA results were presented as maximal total point of motion (MTPM) and segmental motion (translation and rotation), and DXA results were presented as changes in BMD in different regions of interest (ROI).
MTPM at 3, 6, 12, and 24 months was 0.65 mm, 0.84 mm, 0.92 mm, and 0.96 mm for the femoral component and 0.54 mm, 0.60 mm, 0.64 mm, and 0.68 mm, respectively, for the tibial component. The highest MTPM occurred within the first 3 months. Afterwards most of the curves flattened and stabilized. Between 12 and 24 months after surgery, 16% of femoral components had migrated by more than 0.10 mm and 15% of tibial components had migrated by more than 0.2 mm. Percentage change in BMD in each ROI for distal femur was as follows: ROI I 26.7%, ROI II 9.2% and ROI III 3.3%. BMD and at the proximal tibia: ROI I 8.2%, ROI II 8.6% and ROI III 7.0% after 2 years compared with 1 week postoperative results. There was no significant correlation between maximal percentwise change in BMD and MTPM after 2 years.
Migration patterns and changes in BMD related to femoral components after TKA in our study correspond well with previous studies; we observed marginally greater migration with the tibial component.
无菌性松动是全膝关节置换术（TKA）后期翻修的主要原因之一。无菌性松动的风险可通过放射立体测量分析（RSA）检测，借此可测量微小运动（移位），因此在骨科植入物的分阶段引入中推荐使用RSA。通过双能X线吸收法（DXA）测量的骨矿物质密度（BMD）降低与同时通过RSA测量的骨断裂强度相关。本研究的目的是评估TKA术后使用骨水泥固定的不对称胫骨组件和非骨水泥固定的股骨组件在2年随访期内的骨重塑和植入物移位情况。
这是一项针对29例患者（女性/男性患者数量为17/12，平均年龄65.2岁）的前瞻性纵向队列研究，这些患者接受了混合式Persona® TKA（美国印第安纳州华沙市的捷迈邦美公司生产），包括一个骨水泥固定的胫骨组件、一个全聚乙烯髌骨和一个非骨水泥固定的小梁金属股骨组件。随访：术前、术后1周、3、6、12和24个月，并在12个月时对RSA和DXA进行两次检查。RSA结果以最大总运动点（MTPM）和节段运动（平移和旋转）表示，DXA结果以不同感兴趣区域（ROI）的BMD变化表示。
股骨组件在3、6、12和24个月时的MTPM分别为0.65毫米、0.84毫米、0.92毫米和0.96毫米，胫骨组件分别为0.54毫米、0.60毫米、0.64毫米和0.68毫米。最高的MTPM出现在前3个月内。此后，大多数曲线趋于平缓并稳定。术后12至24个月，16%的股骨组件移位超过0.10毫米，15%的胫骨组件移位超过0.2毫米。股骨远端各ROI的BMD百分比变化如下：ROI I为26.7%，ROI II为9.2%，ROI III为3.3%。与术后1周的结果相比，胫骨近端2年后的BMD：ROI I为8.2%，ROI II为8.6%，ROI III为7.0%。2年后BMD的最大百分比变化与MTPM之间无显著相关性。
我们研究中TKA术后与股骨组件相关的移位模式和BMD变化与先前研究结果相符；我们观察到胫骨组件的移位略多。
