Department of Orthopedic Surgery, Korean Armed Forces Daegu Hospital, Gyeongsan, Korea.
Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
Clin Orthop Surg. 2023 Aug;15(4):581-588. doi: 10.4055/cios22082. Epub 2022 Dec 7.
Little is known about the relationship between implant material and periprosthetic bone mineral density (pBMD) in total knee arthroplasty (TKA). The purpose of this study was to investigate the change in pBMD after TKA and to compare pBMD changes between two different implant materials.
A prospective matched-pair case-control study was conducted on 29 patients who underwent bilateral TKAs. The participants were randomly allocated to undergo cemented TKAs with a titanium nitride (TiN)-coated implant on one knee (TiN group) and a cobalt-chromium (CoCr) implant on the other knee (CoCr group). The pBMD was measured using dual-energy X-ray absorptiometry scans before surgery and at 1 and 2 years after surgery. The results were then compared between the two groups. The pBMDs at longer follow-ups (> 2 years) were estimated using simple radiographs (pBMDe).
At 2 years after surgery, the pBMD significantly decreased in both groups at medial metaphysis of the tibia and anterior portion of the distal femur (all < 0.001). The CoCr group showed a larger decrease in pBMD than did the TiN group in the medial and anterior metaphysis of the proximal tibia ( = 0.003 and = 0.046, respectively). The pBMDe was significantly higher in the TiN group at the anterior portion of the distal femur 7 years after surgery ( = 0.019).
The pBMD significantly decreased 2 years after TKA in certain regions regardless of the implant material used. However, the decrease was significantly less in the TiN group in specific regions of the tibia and femur. The TiN implant was beneficial in preserving the periprosthetic bone stock after TKA.
关于全膝关节置换术（TKA）中植入物材料与假体周围骨密度（pBMD）之间的关系知之甚少。本研究旨在探讨 TKA 后 pBMD 的变化，并比较两种不同植入物材料的 pBMD 变化。
对 29 例双侧 TKA 患者进行前瞻性配对病例对照研究。将患者随机分为一侧膝关节行骨水泥固定 TKA 植入氮化钛（TiN）涂层植入物（TiN 组），另一侧膝关节行钴铬（CoCr）植入物（CoCr 组）。手术前及手术后 1、2 年使用双能 X 射线吸收法测量 pBMD。然后比较两组之间的结果。使用简单的 X 射线片（pBMDe）估计随访时间较长（>2 年）的 pBMD。
术后 2 年，两组患者胫骨内侧干骺端和股骨远端前部分 pBMD 均明显下降（均<0.001）。CoCr 组胫骨内侧和前干骺端 pBMD 下降幅度大于 TiN 组（分别为 =0.003 和 =0.046）。术后 7 年，TiN 组股骨远端前部分 pBMDe 明显高于 CoCr 组（ =0.019）。
无论使用何种植入物材料，TKA 后 2 年时某些部位的 pBMD 均显著下降。然而，TiN 组胫骨和股骨的特定部位 pBMD 下降幅度明显较小。TiN 植入物有利于 TKA 后假体周围骨量的保留。
