Diffuse pigmented villonodular synovitis of the foot and ankle treated with surgery and radiotherapy.

We followed up seven patients with histologically confirmed diffuse pigmented villonodular synovitis in a prospective study between 1992 ans 2001. The mean age at diagnosis was 30.7 years. The patients underwent synovectomy, followed by radiotherapy with a total dose of 35 Gy in 20 fractions. In all cases, the excision was considered incomplete when examined histologically. At an average follow up of 24 (18-36) months, six patients reported better function and reduced levels of pain. One patient remained symptomatic but did not have a recurrence. We conclude that a combined approach to a primary pigmented villonodular synovitis of the foot and ankle may reduce the risk of recurrence without functional impairment.

Dedifferentiated chondrosarcoma: use of MRI to guide needle biopsy.

AIM: To describe the use of MRI to identify and biopsy areas of dedifferentiation in patients with a suspected diagnosis of dedifferentiated chondrosarcoma. MATERIALS AND METHODS: Low-grade chondrosarcoma is characterized at magnetic resonance imaging (MRI) as having a lobulate, hyperintense appearance on T2-weighted spin-echo sequences. T2-weighted MR images were assessed in 15 patients with a final pathological diagnosis of dedifferentiated chondrosarcoma for regions of atypical reduced signal intensity. Information regarding the site of ultrasound or computed tomography (CT)-guided biopsy was available in 10 cases. RESULTS: Nine patients were male and six female with a mean age of 60 years (range 25-77 years). The sites involved were the distal femur (n+4) pelvis (n=3) proximal femur (n=4) femoral diaphysis (n=1) proximal humerus (n=2) and proximal tibia (n=1). The dedifferentiated component consisted of osteosarcoma (n=5) malignant fibrous histiocytoma (n=6) spindle cell sarcoma (n=1) leiomyosarcoma (n=1) and pleomorphic sarcoma (n=1). In 14 of the 15 cases, areas of lower signal intensity lacking in lobulation were identified. In nine of the 10 cases, biopsy site included such areas and yielded high-grade sarcoma. CONCLUSIONS: Dedifferentiation within chondrosarcoma may be identified on T2-weighted MRI as areas of reduced signal intensity. These areas should be the preferred site of biopsy.

The use of chondrogide membrane in autologous chondrocyte implantation.

UNLABELLED: Autologous chondrocyte implantation is a new technique for the treatment of chondral defects in the knee. The exact procedure involved is continuously being developed with the ultimate aim of achieving hyaline cartilage regeneration. We present the outcome of our series of 31 patients, focussing on the use of the chondrogide membrane in the implantation process. Assessment is presented both in the form of arthroscopic appearance at approximately 1 year, and in the form of clinical outcome measures at 1 year and at 2 years after the second stage of the procedure. CONCLUSION: the use of chondrogide membrane in the fixation of cells during the implantation process is associated with satisfactory clinical outcome and does not appear to show evidence of hypertrophy at one-year arthroscopy, as compared to periosteum.

Histological evaluation of chondral defects after autologous chondrocyte implantation of the knee.

We have performed a prospective, single-surgeon study analysing the histological results of autologous chondrocyte implantation. Fourteen patients underwent autologous chondrocyte implantation of the knee and were evaluated at one year by clinical assessment and arthroscopy. Standard staining was used to examine the sections. In addition, in situ hybridisation was used to establish type-IIa and type-IIb collagen mRNA expression and immunolocalisation techniques demonstrated the positions of type-II and type-X collagen. Eight patients regenerated hyaline cartilage and also contained type-X collagen in the deepest layers and type-II collagen in the deep layers. Three demonstrated fibrocartilage and had type-I collagen in the deep layers. In situ hybridisation revealed that all 14 samples had the potential to express both type-IIa and type-IIb collagen. We have shown that one year after the initial implantation chondrocytes are capable of producing type-II collagen and that they continue to proliferate and mature.