Yoshikazu Tsuneizumi

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BACKGROUND The middle one-third of the tibial crest in the coronal plane and the fibula in the sagittal plane are known as landmarks for extramedullary guides in total knee arthroplasty (TKA). However, there are few foundational anatomic studies about them. We conducted this study to confirm whether these landmarks are reliable. METHODS We evaluated 100(More)
Tight fixation between bone and implant materials is of great importance for a successful outcome of procedures such as total knee arthroplasty (TKA) and total hip arthroplasty (THA). Titanium fiber mesh is an attractive structure for the establishment of tight fixation between bone and implant by bone ingrowth into the spaces among the fibers. Enhancement(More)
We performed a CT-based computer simulation study to determine how the relationship between any inbuilt posterior slope in the proximal tibial osteotomy and cutting jig rotational orientation errors affect tibial component alignment in total knee replacement. Four different posterior slopes (3°, 5°, 7° and 10°), each with a rotational error of 5°, 10°, 15°,(More)
Retrospective studies demonstrated inadequate soft tissue balance is associated with the long-term outcome of total knee arthroplasty (TKA). However, most of these studies have evaluated the joint laxity only postoperatively without anesthesia. Therefore information about the effect of anesthesia on knee laxity is important for soft tissue balancing at the(More)
Thirty-eight patients diagnosed with osteoarthritis underwent 41 cruciate-retaining total knee arthroplasties. In varus and valgus tests at flexion, subjects were seated on a table at 80° of knee flexion; 50 N was applied perpendicular to the lower leg. The factors affecting the postoperative flexion angle were investigated in a multiregression analysis.(More)
Polymethylmethacrylate (PMMA) bone cement is widely used for prosthetic fixation in orthopaedic surgery; however, the interface between bone and cement is a weak zone. We developed a bioactive PMMA cement through modification with gamma-methacryloxypropyltrimethoxysilane (MPS) and calcium acetate. The purpose of this study was to compare the handling,(More)
A 63-year-old woman with osteoarthritis had undergone right total knee arthroplasty. Nineteen months later, the patient presented with a recurrent hemoarthrosis. Open arthrotomy revealed hypertrophic synovium with small clots in the suprapatellar pouch, but entrapment of synovial tissues could not be observed. Histological examination of the extirpated(More)
The aim of this study was to determine factors that contribute to bone cutting errors of conventional instrumentation for tibial resection in total knee arthroplasty (TKA) as assessed by an image-free navigation system. The hypothesis is that preoperative varus alignment is a significant contributory factor to tibial bone cutting errors. This was a(More)
Computed tomography based computer simulation studies were made on fifty consecutive patients with osteoarthritis scheduled for TKA. Proximal tibial cutting was simulated with the cutting guide placed at different rotational errors (-10°, 0°, 10° and 20° of internal rotation) and different distances (4 cm and 8 cm) between the alignment rod and the bone.(More)
Adjacent segment degeneration (ASD) is one of the major complications of lumbar fusion. Several previous retrospective studies reported ASD after PLIF. However, few reports evaluated whether decompression surgery combined with fusion surgery increases the rate of complications in adjacent segments. The purpose of the current study was to investigate the(More)