Abstract
BackgroundComponent design is one of the contributory factors affecting the postoperative flexion angle. The purpose of this study was to compare short-term outcomes of flat surface and medial pivot designs in posterior cruciate-retaining (CR) total knee arthroplasty (TKA).MethodsA retrospective, case-control, and observational cohort study consisted of matched-pairs of the flat surface design (Hi-Tech Knee II) and the medial pivot design (FINE Knee) in CR-TKA with a two-year follow-up period.ResultsHi-Tech Knee II and FINE knee groups each included 7 males and 38 females. Surgical time was significantly shorter in the FINE Knee group than in the Hi-Tech Knee II group (104.8 min versus 154.9 min, p = 0.001). Estimated total blood loss was significantly lower in the FINE Knee group than in the Hi-Tech Knee II group (654 ml versus 1158 ml, p = 0.001). The postoperative flexion angle was significantly better in the FINE Knee group than in the Hi-Tech Knee II group (119.3 degrees versus 112.5 degrees), and was positively correlated with the preoperative flexion angle. Postoperative Knee Society scores were significantly better in the FINE Knee group than in the Hi-Tech Knee II group (93.0 points versus 85.0 points, p = 0.001), especially for postoperative pain relief (46.0 points versus 39.0 points out of 50, p = 0.001). Complications were not observed in either group over a two-year follow-up period.ConclusionThe short-term outcome of the medial pivot design used in CR-TKA was more favorable than the flat surface design, especially for surgical time, estimated total blood loss, postoperative flexion angle, and knee pain.
Highlights
Component design is one of the contributory factors affecting the postoperative flexion angle
Hi-Tech Knee II CR-type cementless total knee arthroplasty (TKA) (Teijin Nakashima Medical, Okayama, Japan) was developed in 1994 at Chiba University in Japan [2] and has been used for 1918 cases at 73 hospitals until 2016. This prosthesis was designed for the Japanese knee, with 6 fins at the anterior of the femoral component with the same radii in the sagittal plane, with aspect ratios of 0.86, posterior cruciate ligament (PCL) retention, flat-on-flat surface component geometry with 5 degrees of posterior tilt, all-polyethylene patella fixed without cement, strong initial fixation by the center screw of the tibial base plate, 10 layers of titanium alloy fiber mesh, and direct compression molded ultra-high molecular weight polyethylene (UHMWPE) [3]
Patients were similar in age, body mass index (BMI), and preoperative range of motion (ROM) in the Hi-Tech Knee II and FINE Knee groups, height and weight were greater in the Hi-Tech Knee II group (Table 1)
Summary
Component design is one of the contributory factors affecting the postoperative flexion angle. Hi-Tech Knee II CR-type cementless TKA (Teijin Nakashima Medical, Okayama, Japan) was developed in 1994 at Chiba University in Japan [2] and has been used for 1918 cases at 73 hospitals until 2016 This prosthesis was designed for the Japanese knee, with 6 fins at the anterior of the femoral component with the same radii in the sagittal plane, with aspect ratios (anteroposterior/mediolateral) of 0.86, PCL retention, flat-on-flat surface component geometry with 5 degrees of posterior tilt, all-polyethylene patella fixed without cement, strong initial fixation by the center screw of the tibial base plate, 10 layers of titanium alloy fiber mesh, and direct compression molded ultra-high molecular weight polyethylene (UHMWPE) [3].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
