Hideki Date

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.

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.