Center for Joint Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China.
Orthop Surg. 2020 Apr;12(2):429-441. doi: 10.1111/os.12619. Epub 2020 Feb 22.
Total knee arthroplasty (TKA) is one of the most universal and effective means for treating terminal stage osteoarthritis (OA) of knee. Accurate intramedullary guide of femur is the basis for the distal femoral cuts. Determining the surgical transepicondylar axis (sTEA) is the key to reconstruction of the femoral rotational alignment, because the correct rotational alignment can place the femoral component in the right position, balance the flexion gap so that the inner and outer tension is equal, get stability during the flexion process of the knee, and enhance the quality of life of patients. With the development of three-dimensional printing (3DP) technology in the medical domain, the application of patient-specific instrumentation (PSI) in arthroplasty has become more common. The aim of this study was to evaluate the accuracy of a novel 3D-printed patient-specific intramedullary guide to control femoral component rotation in TKA.
Eighty patients (65 females and 15 males) with knee OA were included in this prospective randomized study. The patients were divided into two groups by random number table method, 40 in each group. TKA assisted by PSI (PSI group) and conventional TKA (conventional group) was performed respectively. Clinical outcomes [operation time, postoperative drainage volume, duration of drainage, Hospital for Special Surgery knee score (HSS), American Knee Society knee score (AKS)] and radiological outcomes [hip-knee-ankle angle (HKA), posterior condylar angle (PCA), patella transverse axis-femoral transepicondylar axis angle (PFA), depth of intramedullary guide] were compared between and within the two groups.
PSI group had less postoperative drainage volume but longer operation time than the conventional group (P < 0.05). The AKS and HSS scores after surgery were improved compared with those before surgery in each group (P < 0.05). However, there was no significant difference in the duration of drainage and range of motion (ROM) after surgery between the two groups. For the radiological results, the HKA and PFA were improved after surgery in both groups (P < 0.05).The postoperative PFA and PCA of the PSI group were closer to 0°, which was better than that of the conventional group (P < 0.05). The depth of intramedullary guide in the PSI group was less than the conventional group (P < 0.05). But there was no significant difference in HKA before and after surgery between the two groups as well as the preoperative PFA.
The short-term clinical efficacy of TKA assisted by PSI was similar to the conventional TKA. Although TKA assisted by PSI spent more time during operation, it could assist in intramedullary guide and align femoral rotation more accurately.
全膝关节置换术（TKA）是治疗膝关节终末期骨关节炎（OA）的最常用和最有效的方法之一。股骨髓内准确的导针是股骨远端截骨的基础。确定外科髁间轴（sTEA）是重建股骨旋转对线的关键，因为正确的旋转对线可以使股骨假体放置在正确的位置，平衡屈伸间隙，使内外张力相等，在膝关节屈伸过程中获得稳定性，并提高患者的生活质量。随着三维打印（3DP）技术在医学领域的发展，假体置换中患者特异性器械（PSI）的应用越来越普遍。本研究旨在评估一种新型 3D 打印患者特异性髓内导针在 TKA 中控制股骨假体旋转的准确性。
前瞻性随机研究纳入 80 例膝关节 OA 患者（女性 65 例，男性 15 例）。采用随机数字表法将患者分为两组，每组 40 例。分别采用 PSI 辅助 TKA（PSI 组）和常规 TKA（常规组）。比较两组患者的临床疗效[手术时间、术后引流量、引流时间、美国特种外科医院膝关节评分（HSS）、美国膝关节协会评分（AKS）]和影像学结果[髋膝踝角（HKA）、后髁角（PCA）、髌骨横轴-股骨髁间轴角（PFA）、髓内导针深度]。
PSI 组术后引流量少于常规组，但手术时间长于常规组（P<0.05）。两组患者术后 AKS 和 HSS 评分均较术前改善（P<0.05）。但两组患者术后引流时间和膝关节活动度（ROM）无明显差异。影像学结果显示，两组术后 HKA 和 PFA 均较术前改善（P<0.05）。PSI 组术后 PFA 和 PCA 更接近 0°，优于常规组（P<0.05）。PSI 组髓内导针深度小于常规组（P<0.05）。但两组患者术后 HKA 及术前 PFA 差异均无统计学意义。
PSI 辅助 TKA 的短期临床疗效与常规 TKA 相似。虽然 PSI 辅助 TKA 手术时间较长，但能更准确地辅助髓内导针并调整股骨旋转。
