Assessment of influences of posterior rotation of the tibial condyles on the Insall-Salvati ratio.

The positional relationship between patellar and femoral articular surfaces may vary according to the degree of posterior rotation of the tibial condyle, which may influence the patellar configuration. We hypothesized that the configuration of the patella has a rhomboid transformation similar to that of the tibial condyle. This cohort study included 313 patients with knee pain who underwent lateral-view knee digital radiography.

Lateral shift of the femoral condyle after total knee arthroplasty: simulation using 2D-templates of the medial pivot design on knee radiographs of young Japanese patients.

Background: Total knee arthroplasty (TKA) is an established surgical treatment for advanced knee osteoarthritis by which patients can expect improvement of knee pain and function. Although many surgeons have investigated limb alignment after TKA, changes in coronal positional relation between the femur and tibia are not known well.

Methods: Radiographs of 105 knees of young Japanese patients between 20 and 49 years-old (60 men and 45 women) without osteoarthritic changes who received arthroscopic surgeries at our hospital were used in this study.

Three-year clinical and radiological results of a cruciate-retaining type of the knee prosthesis with anatomical geometry developed in Japan.

Background: The FINE total knee was developed in Japan and clinical use began in 2001. It has unique design features, including an oblique 3 femorotibial joint line that reproduces anatomical geometry. Although 20 years have passed since the FINE knee was clinically used for the first time in Japan, a formal clinical evaluation including patient-reported and radiographic outcomes has not been undertaken.

The posterior tibial slope is mainly created by the posterior rotation of the tibial condyles.

Purpose: Constitutional varus in the coronal plane is formed based on the Hueter-Volkmann's law. The varus deformity occurs at the proximal metaphysis of the tibia and the tibial condyle rotates medially. In the sagittal plane, we hypothesized that the posterior slope angle of the tibial articular surface may also occur at the proximal metaphysis and the tibial condyle rotates posteriorly.

Proximal tibia vara involves the medial shift of the tibial articular surface.

Purpose: According to the concept of the constitutional varus, the tibial articular surface (TAS) has varus inclination. On the other hand, it has been reported that proximal tibia vara involved medial shift of the TAS. However, it has not been assessed whether varus inclination of the TAS has a correlation with the medial shift.

Predicting clinical outcomes after total knee arthroplasty from preoperative radiographic factors of the knee osteoarthritis.

Background: Total knee arthroplasty (TKA) is the major surgical treatment for end-stage osteoarthritis (OA). Despite its effectiveness, there are about 20% of patients who are dissatisfied with the outcome. Predicting the surgical outcome preoperatively could be beneficial in order to guide clinical decisions.

A preclinical method for evaluating the kinematics of knee prostheses.

The primary intent of anatomical knee implants is to replicate the motions of a normal knee joint. In developing such designs, a preclinical evaluation of kinematic behavior is needed. This study introduces an in vitro testing method for recording movements of the knee joint.

Effect of biological agents on synovial tissues from patients with rheumatoid arthritis.

To compare the inflammation of synovium before and after biological agents in the patients with rheumatoid arthritis (RA) and to investigate the association between synovial histopathology and disease activity. Synovial tissues were obtained during operations from 34 patients before and after treatment with biological agents. The synovial tissue was evaluated using hematoxylin and eosin staining.

Association between limb alignment and patient-reported outcomes after total knee arthroplasty using an implant that reproduces anatomical geometry.

Background: A kinematically aligned (KA) total knee arthroplasty (TKA) is expected to improve patient satisfaction, but its effect remains controversial. We investigated differences in patient-reported outcomes (PROs) between KA and non-KA TKAs using an implant that reproduces anatomical geometry.

Methods: TKAs for varus deformity were performed in consecutive 129 patients (149 knees) via a measured resection technique with conventional instruments.

Motion type and knee articular conformity influenced mid-flexion stability of a single radius knee prosthesis.

Purpose: Single radius knee implants were introduced to reduce the level of paradoxical anterior femoral translation (AFT) during mid-flexion after total knee arthroplasty. Findings from clinical and experiment studies are inconsistent, which may be due to the different loading conditions and articular conformities of the knee implants studied. The aim of this study is to analyze how variations in these two factors affect the mid-flexion stability of a single radius knee prosthesis.

A comparative study of flat surface design and medial pivot design in posterior cruciate-retaining total knee arthroplasty: a matched pair cohort study of two years.

Background: Component 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).

Methods: A 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.

Early tissue formation on whole-area osteochondral defect of rabbit patella by covering with fibroin sponge.

Large osteochondral defects have been difficult to repair via tissue engineering treatments due to the lack of a sufficient number of source cells for repairing the defect and to the severe mechanical stresses affecting the replacement tissue. In the present study, whole-area osteochondral defects of rabbit patella were covered and wrapped with a fibroin sponge containing chondrocytes, with or without Green Fluorescent Protein (GFP) transgenic marking, on the surface facing the osteochondral defect. Five of eight osteochondral defects that were covered with the chondrocyte-seeded fibroin sponges showed hyaline cartilage-like repair containing no fibroin fragments at 6 weeks after surgery.

Does use of a biologic agent increase the incidence of postoperative infection in surgery for rheumatoid arthritis after total joint arthroplasty?

Objectives: The goal of the study was to examine the influence of biological agents on postoperative infections such as surgical site infection (SSI) and late infection in patients with rheumatoid arthritis after total joint arthroplasty at our hospital between January 2006 and December 2011.

Methods: The patients were divided into groups with (Bio group, 267 joints) and without (Non-Bio group, 300 joints) treatment with biological agents. We examined the incidence of postoperative infection in Bio group and Non-Bio group.

Analysis of perioperative clinical features and complications after orthopaedic surgery in rheumatoid arthritis patients treated with tocilizumab in a real-world setting: results from the multicentre TOcilizumab in Perioperative Period (TOPP) study.

Objective: To evaluate perioperative changes in rheumatoid arthritis (RA) patients treated with tocilizumab.

Methods: We collected RA cases with tocilizumab and orthopaedic surgery from 1999 to 2010. Incidences of postoperative infections, delayed wound healing, and RA symptom flare-ups were extracted from the data for comparison with patients without these postoperative events.

Perioperative complications in elective surgery in patients with rheumatoid arthritis treated with biologics.

We retrospectively investigated the influence of biological agents on delayed wound healing and the occurrence of postoperative surgical site infection (SSI) in patients after surgery for rheumatoid arthritis. The patients were divided into two groups-those with and without treatment with biological agents (276 and 278 joints, respectively)-and adverse events (delay in wound healing and SSI) were investigated. Wound healing was delayed in 11.

Incidence of venous thromboembolism after spine surgery.

Background: The incidence of venous thromboembolism (VTE) has varied among studies of patients undergoing elective spine surgery. This may be because of differences in prophylaxis for VTE and differences in methods of observation. Furthermore, some studies have reported symptomatic deep vein thrombosis (DVT) or pulmonary thromboembolism (PE), whereas others have included asymptomatic DVT or PE, making comparisons difficult.

Risk of postoperative complications in rheumatoid arthritis relevant to treatment with biologic agents: a report from the Committee on Arthritis of the Japanese Orthopaedic Association.

Purpose: Since biologic agents were introduced to treat rheumatoid arthritis (RA) in 2003, the number of orthopedic surgical procedures under treatment with biologic agents has been increasing in Japan. However, whether biologic agents cause an increase in the prevalence of postoperative complications is as yet unknown. The Committee on Arthritis of the Japanese Orthopedic Association investigated the prevalence of postoperative complications in patients with RA in teaching hospitals in Japan.

Chondrocyte distribution and cartilage regeneration in silk fibroin sponge.

Chondrocytes distribution and cartilage formation in three types of fibroin sponges with different average pore sizes (40-80, 80-120 and 100-140 μm) was measured. The image processing was performed combining two methods to identify cells automatically: extraction of local maximum luminance and multi-threshold analysis. The results showed that initial accumulation of chondrocytes localized at surface area at 3 h in the small and medium-pore groups, however, the difference in the cell distributions become equivalent until 24 h after seeding.

Isolated neck extensor myopathy causing a dropped head: a case report.

This report is of a 71-year-old woman who presented with a dropped head and difficulty in extending her neck. She was diagnosed with isolated neck extensor myopathy. Conservative treatment (use of a cervical collar and muscular strength training) temporarily improved her symptoms.

Recent trends in orthopedic surgery performed in Japan for rheumatoid arthritis.

The aim of this report was to review the use of orthopedic surgeries performed to manage rheumatoid arthritis (RA). Our review of studies published in English indicates that there has been a decrease in RA-associated surgeries in Western countries. Improvements in medical treatment may partly explain the reduction in numbers of orthopedic joint surgeries, which also suggests a worldwide trend toward improved long-term outcomes.

Analysis of the kinematics of total knee prostheses with a medial pivot design.

Analysis of the kinematics of the FINE Total Knee System (Nakashima Medical, Okayama, Japan) revealed that the medial condyle is fixed and the lateral condyle shows lateral posterior movement and tibial internal rotation. Analysis of the kinematics of the ADVANCE Total Knee System (Wright Medical Technology, Arlington, Tenn) revealed that the medial condyle is fixed and the lateral condyle shows anterior movement in the early stage, changing thereafter to posterior movement. With regard to rotation, initial external rotation subsequently changes to internal rotation.

Effect of cage geometry on sagittal alignment after posterior lumbar interbody fusion for degenerative disc disease.

Purpose: To compare the sagittal alignment of the lumbar spine after one-segment posterior lumbar interbody fusion (PLIF) using the horizontal cylinder (HC) or open box (OB) type cage.

Methods: 66 patients underwent instrumented one-segment PLIF with bone grafting for lower lumbar degenerative disease. HC-type cages were used in 33 men and 13 women aged 20 to 73 (mean, 47) years between September 2001 and July 2004.

Acupuncture needle-associated prosthetic knee infection after total knee arthroplasty.

The case of a patient who previously had permanent acupuncture needles placed in the knee joint and had been doing well, with no evidence of infection, but who eventually underwent a revision total knee arthroplasty due to acupuncture needle-associated prosthetic infection is presented. The microorganism responsible for the infection was Enterococcus faecalis, a bacterium which rarely causes infection following arthroplasty. This case should be highlighted to increase the awareness of healthcare providers to acupuncture-associated subclinical infection that may be exacerbated by surgical manipulation.