Clinical value of CT-based patient-specific 3D preoperative design combined with conventional instruments in primary total knee arthroplasty: a propensity score-matched analysis

Abstract

Purpose To evaluate the operation and early clinical effect in primary total knee arthroplasty (TKA) about the novel combination of CT-based patient-specific three-dimensional (3D) preoperative design and conventional osteotomy instruments, compared with the conventional method. Methods After a 1:1 propensity score-matching (PSM), patients were matched to the novel technique group and the conventional group, 109 cases in each group. The conventional group adopted a preoperative design based on a full-length radiograph (FLX) and received TKA with conventional osteotomy instruments. The novel technique group used a CT-based patient-specific 3D preoperative design combined with conventional osteotomy instruments; during the surgery, the femoral entry point, femoral valgus osteotomy angle, the fix point of tibial plateau extramedullary guide pin, and the position of tibial extramedullary positioning rod were accurately selected according to the preoperative 3D design to ensure accurate intraoperative implementation. The lower limb alignment, component position, operation time, tourniquet time, hospital stay, blood loss volume, incidence of postoperative complications, visual analog scale (Vas) score, and New Knee Society Score System (NEW-KSS) at 1 day before operation and 1, 6, and 12 months after operation were recorded and compared. Results The novel technique group was significantly better than the conventional group in controlling lateral tibial component angle (LTC) (P < 0.001), and the novel technique group had lower percentages of hip-knee-ankle angle (HKA) outliers (P < 0.001) and overcorrection (P = 0.003). The operation time, tourniquet time, and hospital stay of the novel technique group was shorter (P < 0.05). In 1 month after the operation, the novel technique group achieved a significantly better VAS score (P < 0.05), but a similar NEW-KSS score (P > 0.05) when compared with the conventional group. But in 6 and 12 months after surgery, no statistical differences were seen in the above two scores (P > 0.05). Conclusion The novel technique of CT-based patient-specific 3D preoperative design combined with conventional instruments can improve the accuracy of osteotomy in primary total knee arthroplasty, with benefits of significantly reducing pain and rapid recovery during the early postoperative period, but having no obvious effect on outcome after a 1-year follow-up.

Comparison of Alignment and Prosthesis Positioning Accuracy Between Robotics and Personalized 3D Preoperative Planning in Total Knee Arthroplasty

“…The previous study only con rmed that personalized 3D preoperative planning could improve osteotomy accuracy compared with conventional TKA [17], while the comparison of alignment and prosthesis positioning accuracy between robotics and personalized 3D preoperative planning has never been reported, to our knowledge. The purpose of this study was to investigate the above issues.…”

“…The personalized 3D preoperative planning [17] and Legion® primary total knee prosthesis (Smith-Nephew, Inc., Memphis, IN, USA) were used in the 3D preoperative planning group. The lower limb fulllength Computed Tomography (CT) data of patients was collected to performed 3D reconstruction with Mimics Research 19.0.…”

“…With the CATIA 5.20 and NX12.0 software, the engineers and surgeons at our Center formulated the personalized 3D preoperative planning, which should include the following key information: the femoral entry point, the coronal projection angle of the Hip-Knee-Shaft (HKS), the transverse projection angle of the posterior condylar angle (PCA), the x point of the tibial plateau extramedullary guide pin, the volume of femoral and tibial osteotomy, etc. [17] During the intraoperative implementation, the femoral entry point was strictly located according to the preoperative plan, and the coronal projection angle of HKS and the speci c osteotomy volume were used in the distal femoral osteotomy. And the femoral rotatory osteotomy was guided by the transverse projection angle of PCA.…”

“…To achieve accurate alignment and prosthesis positioning as cost-effectively as possible, a veri ed technique named personalized 3D preoperative planning was introduced [17], which could be considered as a simpli ed PSI without cutting guides. During the intraoperative implementation, multiple markers such as the femoral entry point and the x point of tibial plateau extramedullary guide pin were used for positioning by conventional osteotomy instruments according to the personalized 3D preoperative planning, rather than the patient-speci c cutting guides.…”

“…During the intraoperative implementation, multiple markers such as the femoral entry point and the x point of tibial plateau extramedullary guide pin were used for positioning by conventional osteotomy instruments according to the personalized 3D preoperative planning, rather than the patient-speci c cutting guides. The advantages of this technique include personalized preoperative planning, relatively precise intraoperative positioning, no need to purchase new equipment, better control of the surgical time and cost, and easier application due to similar procedures with conventional TKA [17].…”