Kazue Hayakawa

Ender nailing for supracondylar fracture of the femur after total knee arthroplasty: Five case reports

We studied 5 women with supracondylar fractures after total knee arthroplasty (TKA). The mean age at fracture was 67.4 years. Four patients had chronic rheumatoid arthritis, and 1 had osteoarthritis. The range of motion, knee score, femorotibial angle, and component alignment were investigated. Flexion was slightly decreased after Ender nailing, but extension only changed in 1 patient. The knee score decreased, but all patients were ambulatory. The femorotibial angle changed in all patients. Measurement of femoral component alignment showed a postoperative change of angle alpha (1 degrees to 11 degrees ) and angle gamma (0 degrees to 9 degrees ). Union was achieved in all patients. Ender nailing is an acceptable method of treatment for supracondylar fractures of the femur after TKA if the nails can be inserted deeply into the femoral condyles.

Mid-term results of total knee arthroplasty with a porous tantalum monoblock tibial component.

BACKGROUND The objectives of the present study were to assess the mid-term results of cementless total knee arthroplasty (TKA) with the porous tantalum monoblock tibial component and to examine the time course of bone changes on plain radiographs. METHODS The subjects were 32 patients, 29 patients were available for follow-up. We investigated the mid-term results of TKA after a mean follow-up period of 7 years and 8 months. We also examined changes of the bone over time on plain radiographs. RESULTS The Knee Society Clinical Rating scores showed significant improvement. Bone changes around the tibial component were as follows: new bone formation and longitudinal trabecular thickening in 41.4% (Type A), only longitudinal trabecular thickening in 41.4% (Type B), and no changes in 17.2% (Type C). Type A and B changes were more frequent in patients with osteoarthritis, whereas Type C was only seen in patients with rheumatoid arthritis. Three knees had an initial gap, but this disappeared in all cases, and no new radiolucent lines were detected. Stress shielding was observed in seven knees (21.9%), but there was no implant loosening related to it. When we examined the relationship between the mechanical axis and the locations of the tips of the tibial pegs in patients with or without stress shielding, no significant differences were found. CONCLUSIONS The results of mid-term follow-up have demonstrated favorable bone ingrowth, suggesting that porous tantalum is a promising material for cementless TKA.

Snapping knee due to the biceps femoris tendon treated with repositioning of the anomalous tibial insertion

AbstractSnapping knee associated with biceps femoris tendon that caused lateral knee pain is reported. The long head of the biceps femoris tendon had an anomalous tibial insertion in addition to the direct arm and anterior arm on the fibular head. Resection of both the anomalous tibial insertion and the anterior arm was necessary to resolve the snapping. Level of evidence IV.

Novel approach to identifying autoantibodies in rheumatoid synovitis with a biotinylated human autoantigen library and the enzyme-labeled antigen method

Synovial tissue in rheumatoid arthritis (RA) shows dense infiltration of plasmacytes. The purpose of the present study is to identify and localize autoantibodies produced in these immunocytes in RA synovitis. We developed a novel screening system for detecting specific autoantigens. Protein antigens recognized by antibodies in the serum and synovial tissue extract from five RA patients were screened with the AlphaScreen method. For screening, a biotinylated human autoantigen library was constructed by the wheat germ cell-free protein synthesis system. The AlphaScreen analysis of 2183 proteins detected a limited number of antigens reactive with the serum and synovial tissue extract. Eighteen biotinylated proteins, containing top five showing high signals in each synovitis tissue extract, were utilized as probes for the enzyme-labeled antigen method, in order to visualize the site of specific antibody production in synovial lesions. Specific antibodies against two proteins, tripartite motif-containing 21 (TRIM21, also known as SSA/Ro52) and F-box only protein 2 (FBXO2), were visualized in the cytoplasm of plasmacytes in two RA synovitis lesions, respectively. Absorption experiments using unlabeled proteins confirmed the specificity of staining. No positive signals against these two proteins were identified in the additionally evaluated RA and osteoarthritis synovial lesions. The present study indicated 1) the usefulness of screening the human autoantigen library with the AlphaScreen assay for detecting autoantibodies in RA synovitis, and 2) the applicability of biotinylated proteins to the enzyme-labeled antigen method for visualizing the site of autoantibody production within the lesion.

Allograft bone transplantation for neuropathic arthropathy of the knee associated with type 1 diabetes mellitus

Diabetes mellitus causes neuromusculoskeletal disorders characterized by abnormalities of nervous tissue, joint and bone. Early diagnosis and prevention of disease progression is difficult in cases of neuropathic arthropathy of the knee in diabetes. We report the case of a patient with type 1 diabetes mellitus who developed an insufficiency fracture of the medial part of the proximal tibia, which was viewed as an early finding of neuropathic arthropathy of the knee. In surgical treatment of the fracture, allograft bone transplantation and internal fixation were performed after curettage of the pathologically fragile lesion. Postoperatively, radiological findings have showed complete allograft bone incorporation and no evidence of degenerative changes. Recognition of an insufficiency fracture of the knee as an early indicator of neuropathic arthropathy and prompt treatment of the fracture using allograft bone transplantation could result in joint preservation.

Revision Total Knee Arthroplasty due to Rheumatoid Arthritis after Unicompartmental Knee Arthroplasty: A Case Report

Objective: We report a rare case of revision total knee arthroplasty for monoarthritis of the knee due to rheumatoid arthritis (RA). Case: The patient was a 72-year-old woman, who underwent revision surgery at 8 years and 7 months after left unicompartmental knee arthroplasty. Bacteriological examination of the synovial fluid was negative, and no crystals were found by microscopic examination. When the Knee Society score was determined, the knee score was 43 points and the function score was 45 points. No periprosthetic radiolucent lines were observed and there was no loosening. Erosion of the lateral femoral and tibial condyles was observed. CRP 3.6 mg/dL, erythrocyte sedimentation rate 129 mm/h, RF 101 U/mL, MMP3 732.2 ng/mL, anti-CCP antibody 190.3 U/mL. Revision TKA was done with a NexGen CR Flex (Zimmer Corp.) RA was diagnosed by histopathological examination of the synovium. Detailed investigation with bone scintigraphy and gallium scintigraphy did not identify inflammation of any other joints. However, pain and swelling of the right knee joint appeared 5 months after revision surgery, and right TKA was performed. Histopathological examination of the synovium resected from the right knee also revealed findings typical of RA. Discussion: Revision TKA is likely to increase in the future because of more patients undergoing UKA and an increase in the age of onset of RA. If knee pain occurs in patients after unicompartmental knee arthroplasty, monoarthritis due to RA should be considered as a possibility. Accordingly, we should follow patients after UKA while keeping the possibility of RA in mind.

Treatment of Infected Total Knee Arthroplasty

Abstract: The primary aim of treating infected knee joints after total knee arthroplasty is to eradicate the infection, but this is difficult to achieve. In patients with rheumatoid arthritis affecting multiple joints and active patients with osteoarthritis, revision achieves the best functional outcome. If there is no loosening, preservation of the implant should be attempted. However, if preservation is not possible, revision should be performed when feasible. We believe that patient education is needed to encourage early attendance at the first sign of infection, as well as a hospital system that allows treatment to be started immediately after infection is detected.