The posterior slope of the tibial component in total knee arthroplasty (TKA) has been reported to vary widely even with computer assisted surgery. In the present study, we analyzed the influence of posterior tibial slope on one-year postoperative clinical outcome after posterior-stabilized (PS) -TKA to find out the optimal posterior slope of tibial component. Seventy-three patients with varus type osteoarthritic (OA) knees underwent PS-TKA (Persona PSR) were involved in this study. The mean age was 76.6 years old and preoperative HKA angle was 14.3 degrees in varus. Tibial bone cut was performed using standard extra-medullary guide with 7 degrees of posterior slope. The tibial slopes were radiographically measured by post-operative lateral radiograph with posterior inclination in plus value. The angle between the perpendicular line of the proximal fibular shaft axis and the line drawn along the superior margin of the proximal tibia represented the tibial slope angle. We assessed one-year postoperative clinical outcomes including active range of motion (ROM), patient satisfaction and symptoms scores using 2011 Knee Society Score (2011 KSS). The influences of posterior tibial slope on one-year postoperative parameters were analyzed using simple linear regression analysis (p<0.05).Background
Materials and Method
Modified gap technique has been reported to be beneficial for the intraoperative soft tissue balancing in posterior-stabilized (PS) -TKA. We have found intraoperative ligament balance changed depending on joint distraction force, which might be controlled according to surgeons' fells. We have developed a new surgical concept named as “medial preserving gap technique (MPGT)” to preserve medial knee stability and provide quantitative surgical technique according to soft tissue balance measurement using a tensor device. The purpose of this study was to compare 3-years postoperative knee stability after PS-TKA in varus type osteoarthritic (OA) knees between MPGT and measured resection technique (MRT). The subjects were 94 patients underwent primary unilateral PS-TKA for varus type OA knees. The surgical technique was MPGT in 47 patients and MRT in 47 patients. An originally developed off-set type tensor device was used to evaluate intraoperative soft tissue balance. In MPGT, medial release was limited until the spacer block corresponding to the bone thickness from proximal lateral tibial plateau could be easily inserted. Femoral component size and external rotation angle were adjusted depending on the differences of center gaps and varus angles between extension and flexion before posterior femoral condylar resection. The knee stabilities at extension and flexion were assessed by stress radiographies at 1 and 3 years after TKA; varus-valgus stress test at extension and stress epicondylar view at flexion. We measured medial and lateral joint openings (MJO, LJO) at both knee extension and flexion. MJOs and LJOs at 2 time periods were compared in each group using paired t-test. Each joint opening distance was compared between 2 groups using unpaired t-test. The significance level was set as P < 0.05.Introduction
Material & Method
We assessed the usefulness of vascularized bone transfer for treatment of aggressive musculoskeletal tumours. Classification by reconstruction method with vascularized bone transfer of our 33 patients was made into five types: 1) intercalary type in 6 cases, 2) arthrodesis type in 5 cases, 3) arthroplasty type using fibular head in 8 cases, 4) hybrid type with recycling autograft as heat treated bone or irradiated bone in 4 cases, and 5) inlay type after curettage of benign tumour chiefly for femoral head and/or neck in 10 cases. From October 1975 to December 1999, 33 patients composed of 18 males and 15 females with age ranging from 9 to 69 years (average of 30 years) received vascularized bone transfer. There were 28 cases of bone tumour and 5 cases of soft tissue tumour. In 31 cases we grafted the fibula of 8 to 20 cm in size and in 2 cases the ileum of 8 cm in size. Postoperative follow-up period ranged from 10 months to 15 years with average of 65 months. Primary union was achieved in 31 cases postoperatively between 1.5 month and 4 months with average of 3 months. As complication, we observed fracture of the graft in 4 cases and local recurrence in 3 cases. Postoperative functional evaluation ranged from 33.3% to 96.7% with average of 76.7%. As for oncological therapeutic results, continuous disease free cases accounted for 27, case of no evidence of disease for 1, case alive with disease for 1, and cases of death of disease for 4. Intercalary transfer of vascularized bone is best indicated for defect of long bone. Arthrodesis was performed in only one knee joint where reconstruction with prosthesis is usually indicated. In arthroplasty type, remodeling of fibular head was observed. In hybrid type, rapid bone union and low complication rate can be expected when compared to recycling autograft alone. In inlay type, femoral head necrosis even after wide curettage can be prevented.
