Nobuki Terada

Hyaluronan in synovial fluid of patients with loose total hip prosthesis

Abstract The concentration and molecular weight of hyaluronan (HA) in the synovial fluid of the hip joint were determined in 13 patients (aged 62.8 ± 9.4 years) who had undergone prior total hip arthroplasty(THA), 23 patients (aged 65.0 ± 8.2 years) with osteoarthritis of the hip joint (OA), and 13 patients (aged 40.2 ± 2.7 years) with idiopathic osteonecrosis of the femoral head (ION). A sample of synovial fluid was obtained during revision THA because of loosening of the total hip prosthesis for the THA group, and during the first replacement surgery or osteotomy for the OA and ION groups. The concentration of HA in the synovial fluid was 0.64 ± 0.42 mg/ml in the THA group, 1.07 ± 0.28 mg/ml in the OA group, and 1.30 ± 0.56 mg/ml in the ION group. The concentration of HA in the synovial fluid of the THA patients was significantly lower than that of the OA and ION patients (P = 0.0156 vs OA, P = 0.003 vs ION). The molecular weight of HA was 309 ± 88.3 × 104 Da in the THA group, 377 ± 201 × 104 Da in the OA group, and 240 ± 148 × 104 Da in the ION group; these values do not differ significantly (P = 0.259 vs OA, P = 0.174 vs ION). Among the THA patients, there was no relation between the concentration of HA and the age of the patient, length of time since the first operation, or type of prosthesis fixation; there was also no relation between the molecular weight of HA and each of these factors. These results suggest that a pseudo-synovial membrane is regenerated after THA, and that it produces HA of the same molecular weight as that in patients with OA and ION, although in smaller quantities.

Expression of tumor necrosis factor-alpha converting enzyme and matrix metalloproteinase-3 in proliferated synovium in a patient with synovitis-acne-pustulosis-hyperostosis-osteitis syndrome: a case report

IntroductionSynovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome is a rare disorder. The etiology remains unknown and the treatment is still empirical. Synovitis is one of the major manifestations, but information on histopathological features is still lacking. In this case, we investigated the histopathological features of SAPHO syndrome synovitis.Case presentationWe present the case of a 53-year-old Japanese woman with SAPHO syndrome accompanied by marked knee synovitis and palmoplantar pustulosis. We found abundant sterile joint fluid in the right knee, and a blood test showed abnormally high values of C-reactive protein (17.26 mg/dl) and matrix metalloproteinase-3 (800 ng/ml). Arthroscopic surgery revealed marked proliferation of villous synovial tissues similar to rheumatoid arthritis and standard microscopic findings were also similar to rheumatoid arthritis. Furthermore, for the first time, we demonstrated by immunohistochemistry the expression of tumor necrosis factor-alpha (TNF-α) converting enzyme, TNF-α and matrix metalloproteinase-3 in the proliferated synovial lining cells. After arthroscopic synovectomy, her knee symptoms immediately diminished and laboratory data (matrix metalloproteinase-3 and C-reactive protein) normalized within 2 weeks of surgery.ConclusionWe demonstrate the expression of TNF-α converting enzyme, TNF-α and matrix metalloproteinase-3 in SAPHO syndrome synovitis for the first time and also show, both macro- and microscopically, the similarity between SAPHO syndrome and rheumatoid arthritis synovitis. These new findings support the recently reported successful treatment of SAPHO syndrome with antirheumatic drugs, especially with anti-TNF-α agents.

Entrapment of the Flexor Hallucis Longus Tendon by Direct Impalement in the Osseofibrous Tunnel Under the Sustentaculum Tali: An Extremely Rare Complication of a Calcaneal Fracture

Case: This article presents a case of entrapment of the flexor hallucis longus tendon in the osseofibrous tunnel under the sustentaculum tali due to a bone fragment from a calcaneal fracture. Despite good visualization with computed tomography, we did not recognize this complication preoperatively. Limited motion of the hallux was the key to recognition of this rare pathogenic situation. Conclusion: We emphasize the importance of careful physical examination of the forefoot when there is a hindfoot injury.

Expression of keratan sulfate at the arthroplasty surface after cup arthroplasty

Abstract Fibrous tissue which regenerated on the acetabular arthroplasty surface was obtained from a 52-year-old woman who underwent total hip replacement after cup arthroplasty. The histological features of this newly formed fibrous tissue and expression of keratan sulfate, which is a characteristic matrix component of articular cartilage, were studied. Microscopic observation revealed that the arthroplasty surface consisted mainly of fibrous tissue which did not show metachromasia with toluidine blue staining, but there were many nodular structures communicating with the bone marrow. Immunostaining for keratan sulfate revealed clear positive staining around the cells of the nodular structures communicating with the bone marrow, while only weakly positive staining was observed in the superficial layer of the loose fibrous tissue. The present study revealed marked formation of articular cartilaginous tissue in areas having good communication with the bone marrow, which indicates that maintenance of this communication may be necessary to improve the outcome of cup arthroplasty.

Cine MRI of the Triangular Fibrocartilage Complex during Radial–Ulnar Deviation

Purpose Changes in the shape of the triangular fibrocartilage complex (TFCC) during radial‐ulnar deviation were studied using “cine‐mode” magnetic resonance imaging (MRI) in 10 right wrists of healthy volunteers, 5 wrists of TFCC tear, and 5 wrists of ulnar styloid nonunion. Subjects and Methods The wrist was fixed in a custom acrylic device, which only allows radial and ulnar deviation. Coronal MR images of nine radial‐ulnar deviated positions (every 5 degree from 15 degrees radial deviation to 25 degrees ulnar deviation) were obtained in volunteers and patients. Cine‐mode MRI was assembled and was output to MPEG video to observe. Results Cine MRI demonstrated the ulnar side of the TFCC was elongated by average 15 mm in 15 degrees of radial deviation and shortened by average 8 mm in 25 degrees of ulnar deviation in all normal TFCC subjects. Distal portion of the triangular fibrocartilage (TFC) was compressed during radial‐ulnar deviation in 10 healthy volunteers and in 3 patients, but proximal portion of the TFC was stable throughout the motion. In contrast, the wavy deformities on the disc in ulnar deviation were observed in three patients with horizontal tear inside the TFCC. In nonunion of the ulnar styloid process, the fragment was snapped in maximum ulnar deviated position or elongation of the space between the styloid fragment and ulna was seen. Conclusion This study indicated normal and abnormal changes in the shape of the TFCC during radial‐ulnar deviation motion on cine MRI. The abnormal dynamic changes of the TFCC may be seen in ulnar deviated position in patients, which are related to positive ulnocarpal stress test with the wrist forced ulnar deviated.