תוצאת חיפוש

ערן תמיר, דרור רובינסון, גבריאל אגר, נחום הלפרין

המח' לאורתופדיה, מרכז רפואי אסף הרופא, צריפין

חומצה היאלורונית היא מולקולת ענק במשקל מולקולתי של 3.5-5 מיליון דלטון, המורכבת משרשרת פוליסאכארידית של D-glucuronate ו-N-acetylglucosamine המופיעים לסירוגין. חומצה היאלורונית מיוצרת על ידי תאים מסוג A בריקמה הסינובית של המיפרק ומהווה מרכיב חשוב התורם לתכונות המגנות של הנוזל הסינובי, הכוללות בלימת זעזועים ושימון המישטחים הסחוסיים. בנוסף לכך המישטח הפנימי של הממברנה הסינובית מצופה בשיכבת חומצה היאלורונית, המונעת נדידת תאים ומולקולות גדולות לתוך המיפרק.

Autologous Chondrocyte Transplantation - from Science Fiction to Routine Clinical Practice

Dror Robinson, Hana Ash, David Aviezer, Gabriel Agar, Nahum Halperin, Zvi Nevo

Dept. of Clinical Biochemistry, Sackler Medical School, Tel Aviv University, Ramat Aviv; Dept. of Orthopedic Surgery, Assaf Harofeh Medical Center, Zerifin; and CTI Ltd., Science Park, Kiriat Weizmann, Nes Ziona

Adult articular cartilage lacks the capacity for self-repair. The limiting factor appears to be the inability of chondrocytes to proliferate while embedded in the extracellular matrix typical of hyaline cartilage. Cartilage defects larger than 1 cm² change articular biomechanics and lead to eventual osteoarth-ritis and joint destruction.

During the past decade, several competing techniques have evolved to stimulate articular cartilage repair. Small lesions can be successfully treated by either micro-fracture or osteochondral cylinder grafting. The latter technique allows immediate weight bearing but leads to damage of previously uninvolved areas of articular cartilage, which limits its application to lesions of less than 2 cm².

When the damaged area is more extensive, grafting of autologous chondrocytes should be considered. First a diagnostic arthroscopy is performed to assess the damaged area and a small cartilage biopsy is taken. 6 weeks later, arthrotomy and chondrocyte transplantation are performed. In the interval, the antologous chondrocytes have expanded by 2 to 3 orders of magnitude. Our experience to date includes 10 cases with follow-up of 6 months to 5 years. Preoperative complaints of crepitation and locking disappear. There is functional improvement and pain reduction of approximately 50%. This procedure, currently limited to patients under 55 years of age with limited damage to an articular surface, for the first time allows reconstruction of damaged articular areas without resorting to allografts.

Spinal and Extra-Spinal Tumors Mimicking Discal Herniation

E. Tamir, Y. Mirovsky, D. Robinson N. Halperin

Orthopedics Dept., Assaf Harofeh Medical Center, Zerifin

Low back pain radiating to a limb is usually caused by lumbar disc herniation. Tumors of the spinal cord or near the sciatic or femoral plexus can cause neural compression and clinical signs similar to those of disc herniation. Such tumors are usually misdiagnosed as discal herniation and appropriate treatment is delayed. We present 4 men who had tumors causing low back pain radiating to the leg: a 70-year-old with metastatic squamous cell carcinoma of the lung, a 20-year-old with aneurysmal bone cyst of the vertebral column, a 52-year-old with retroperitoneal sarcoma and a 32-year-old who also had retroperitoneal sarcoma. Diagnosis and trwere delayed because the clinical symptoms were ascribed to lumbar disc herniation. The latter 2 patients had CT-scans showing lumbar disc herniation, but similar findings are common among asymptomatic individuals.

The differential diagnosis of low back pain radiating to the leg should include tumor when there is a history of cancer, pain not relieved by conservative treatment nor by lying down, pain is increased at night, pain accompanied by weight loss, and when physical examination demonstrates injury to more than 1 nerve root. In these circumstances work-up should include EMG, radioisotope scan and CT of the pelvis.

Epidural Spinal Abscess

E. Tamir, Y. Mirovsky, N. Halperin

Orthopedics Dept., Assaf Harofeh Medical Center, Zerifin

A 42-year-old man was admitted for fever and severe low back pain radiating to both legs. On MRI, an epidural spinal abscess from S1 to D10 was seen. Treatment included laminectomy, drainage of the abscess and antibiotics. Recovery was complete without neurological damage. Increased awareness of this disease may lead to diagnosis and treatment.

Technetium 99-M Sestamibi Bone Scan in Musculo-Skeletal Neoplasms

Dror Robinson, Lena Pinkas, Lilia Mindlin, Nahum Halperin, Tifha Horn

Dept. of Orthopedics and Nuclear Medicine, Assaf Harofeh Medical Center, Zerifin

It is often difficult to assess accurately the nature of a skeletal lesion. Problems include differentiating a malignant from a benign bone tumor, as well as determining the cause of a pathologic fracture. Such fractures may occur through osteoporotic bone as well as through neoplasm-affected bone. Thus, development of an imaging modality capable of distinguishing between such lesions is of importance. During 1996, we ran a prospective study in which results of Tc-99m-methyl-diphosphate (MDP) bone scans were compared with those of sestamibi (MIBI) bone scans and with subsequent biopsy and clinical course. The results of the bone scans were assessed by 2 independent "blinded" observers, and the ratios of counts in lesions to those in normal tissue (L/N ratios) were calculated. In cases of malignant (7) and benign (8) tumors, intensity of uptake in MDP scans were not predictive of degree of aggressiveness. On the other hand, MIBI bone scans demonstrated significant difference in intensity of uptake between benign and malignant bone tumors (L/N ratios 2.05 vs 2.75). In 5 of 8 benign lesions the L/N ratio was 1. In the others, increased uptake was minimal. In 2 patients changes in uptake in MIBI bone scan following chemotherapy appeared to be related to the degree of tumor necrosis achieved. While the MIBI bone scan cannot replace tissue biopsy as a definitive diagnostic modality in bone neoplasms, it does appear to allow better preoperative assessment and prognosis.