Synthetic bone graft substitutes

Replacement of extensive local bone loss is a significant clinical challenge. There are a variety of techniques available to the surgeon to manage this problem, each with their own advantages and disadvantages. It is well known that there is morbidity associated with harvesting of autogenous bone graft and limitations in the quantity of bone available. Alternatively allografts have been reported to have a significant incidence of postoperative infection and fracture as well as the potential risk of disease transmission. During the past 30 years a variety of synthetic bone graft substitutes has been developed with the aim to minimize these complications. The benefits of synthetic grafts include availability, sterility and reduced morbidity. The present article examines the relevance of synthetic bone graft substitutes, their mechanical properties and clinical application.     

Adult soft tissue sarcoma.

BACKGROUND: Soft tissue sarcomas (STS) are a group of anatomically and histologically diverse tumours. They account for about 1% of adult malignancies, and about 50% of patients diagnosed with sarcoma eventually die of the disease. These tumours are grouped together because of shared biological characteristics and treatment responses. METHODS: A review of the key literature on STS was undertaken, complemented by data taken from the prospectively accumulated database of 3442 patients treated for STS at Memorial Sloan-Kettering Cancer Center (MSKCC) from July 1982 to December 1997. RESULTS: Despite advances in knowledge of the molecular genetics of STS, the aetiology in most cases remains elusive. Management has been gradually refined over the last two decades. Core biopsy usually provides enough material for diagnosis. Computed tomography and magnetic resonance imaging provide a similar amount of information, which is usually adequate for surgical planning. Amputation as standard treatment for extremity lesions has been replaced by limb-sparing surgery in about 90% of patients. The role of adjuvant radiation has been further defined: it has been shown to be unnecessary for completely excised tumours less than 5 cm in diameter, but effective in decreasing local recurrence for others. Adjuvant chemotherapy has been controversial for many years. Recent meta-analysis of randomized trial results has found a small reduction in local and distant relapse, and a trend to better overall survival. Recurrent or metastatic disease should be completely excised if possible. CONCLUSIONS: Soft tissue sarcoma requires multidisciplinary care tailored to the individual patient and tumour for optimal results.     

Myolipoma of soft tissue.

Nine cases of a previously undescribed benign soft tissue tumor are reported. They were composed of variable amounts of benign smooth muscle and mature adipose tissue. Patient ages ranged from 28 to 73 years. One was located in the subcutaneous adipose tissue, one in the rectus sheath of the anterior abdominal wall, two within the abdominal cavity and attached to the abdominal wall, two in the inguinal region, and three in the retroperitoneum. Sizes varied between 3.5 and 26 cm and averaged 16 cm in greatest dimension. Two of the retroperitoneal tumors were incidental findings during other operative procedures. The remaining seven cases were clinically palpable masses. Eight of the nine lesions were originally diagnosed as benign, and another (retroperitoneal) was diagnosed as well-differentiated liposarcoma. Five of the tumors were at least partially encapsulated. In three of the cases, a nonlipomatous component was grossly recognized. Although the benign nature of this lesion is usually recognized in superficial locations, deeply situated tumors are more likely to be confused with a well-differentiated liposarcoma.     

Tissue engineering: in vitro creation of tissue substitutes

Tissue engineering is a young, multidisciplinary scientific field which aims at generating bioartificial tissues in vitro to restore diseased human organs. This fledgling sector of biosciences emerged few years ago but draws scientific and public attention increasingly, as the recent accomplishments are impressive and promise alternative therapeutic concepts to replace or enhance failing human organs. Tissue engineering using either polymers or decellularized native allogeneic or xenogeneic matrices may provide the techniques to develop the ideal graft. The matrix scaffold can be seeded with cells that organise and develop into tissue prior to or following implantation. This review surveys upon recent developments in the field of in vitro tissue engineering (skin, heart, heart valves, blood vessels, liver, kidney, urogenital, and nerves), without claiming completeness, thus providing an insight into what has been attempted and what may be possible in the near future.     

Lymphoma presenting as a soft tissue mass. A soft tissue sarcoma simulator

Lymphoma presenting as a soft tissue mass is rare and thus may be confused with the more common soft tissue sarcoma. No previous analysis of the clinical and radiologic features of lymphomas presenting as soft tissue masses is available because most of the cases reviewed are from the pathology literature. Four patients with diagnoses of extranodal lymphomas of the soft tissues were reviewed retrospectively with respect to their clinical features, primary tumor characteristics, stage, radiographic characteristics, treatment, and followup. Mean age was 72.5 years (range, 52-85 years). The soft tissue mass occurred in the thigh (three cases) and shoulder (one case). The median size of the soft tissue mass was 6.7 cm (range, 2-15 cm) in the largest dimension, as measured on magnetic resonance imaging. These patients each had evidence of lymphadenopathy at the time of diagnosis. Lactate dehydrogenase was increased significantly in two cases and increased slightly in two other cases. One case was Stage II(E) at presentation, one was Stage III(E), and two were Stage IV. All were B cell immunophenotype. All patients died between 2 and 24 months after diagnosis, despite the use of Cytoxan, vincristine, adriamycin, and prednisone chemotherapy in each case. Clinical and radiographic features that favor extranodal soft tissue lymphoma over sarcoma include pain and tenderness, lymphadenopathy (particularly when confluent radiologically), ipsilateral extremity swelling, and elevated lactate dehydrogenase.     

Overview: soft tissue augmentation

No single filler substance meets all of a clinician's expectations. There are, however, many substances currently available that are useful in the soft tissue armamentarium. This article reviews the many filler substances; their indications, shortcomings, complications, and approval status by the Federal Food and Drug Administration.     

软组织恶性纤维组织细胞瘤的治疗(附12例报告)

发生于软组织的恶性纤维组织细胞瘤１２例，平均年龄６１．９岁，平均随访２９个月。本病与发生在骨组织的恶性纤维组织细胞瘤不同，病理学还可分为席纹样－多形性型、粘液样型、巨细胞型、黄色肉芽肿型。本病局部广泛切除可以得到较好的治疗，综合治疗特别放疗及化疗药物的应用，对减少复发，治疗转移有一定的疗效。     

Management of soft tissue injury.

The fate of a surgical wound is held in a delicate balance between the host's resistance to infection and the causal factors of infection. Considerable insight into this relationship between the host and pathogen can be gained from the results of quantitative bacteriologic measurements. Newer rapid slide techniques have been developed which provide the surgeon with this information within 20 minutes. In most soft tissue injuries, the wound bacterial count gives an accurate prediction of subsequent infection. Wounds combining greater than 10(5) bacteria per gram of tissue are destined to develop infection. When the bacterial count is below that level, the wounds will usually heal per primam without infection. This large number of bacteria required to elicit infection reflects the remarkable ability of soft tissues to resist infection. This state of high resistance to infection can be reduced by several factors which include circulatory embarrassment, tissue injury, dead space, and the presence of foreign bodies (dirt, sutures, drains, etc.). When treating soft tissue injuries, the surgeon must employ specific therapeutic modalities that allow the wound to heal per primam without infection. On the basis of experimental studies supported by clinical experience, the following treatment protocol for soft tissue injuries is recommended. Using strict aseptic technique, the wound must be first anesthetized with 1 per cent Xylocaine to permit painless sound cleansing. All wounds should be subjected to high pressure syringe irrigation to remove bacteria, foreign bodies, and blood clots. When necessary, debridement of all devitalized tissue should be performed with a stainless steel scalpel. Many wounds caused by sharp wounding agents contain no foreign bodies and few bacteria and exhibit considerable resistance to infection. In these wounds, primary closure can be initiated after irrigation without the development of infection. Wounds resulting from impact forces have a diminished resistance to infection and are susceptible to infection by low level of bacterial contamination. Immediate antibiotic treatment of patients with impact injuries subjected to meticulous debridement and cleansing will permit a safe primary closure. In wounds contacted by pus or feces, open wound management followed by delayed primary closure is usually indicated. Antimicrobial prophylaxis is also recommended for patients with such wounds. Ideal postoperative care of all traumatic wounds includes a surgical dressing and immobilization and elevation of the site of injury.     

Rosai-Dorfman disease of soft tissue.

Whereas Rosai-Dorfman disease (RDD) or sinus histiocytosis with massive lymphadenopathy is well described in lymph nodes and other organs, it is frequently not recognized in soft tissue. We studied the clinical and histologic features of 23 previously unreported soft tissue lesions from 17 patients (13 females, 4 males) who were 24 to 66 years of age (mean, 46 years). These lesions involved the extremities (12, 52%), trunk (6, 26%), head and neck (3, 13%), and the retroperitoneum (2, 9%). Associated lymph node involvement was present in four cases; most patients were asymptomatic. RDD of soft tissue had more subtle histologic features than its lymph node counterpart. Emperipolesis was less conspicuous and proliferating histiocytes were frequently spindled, associated with collagen deposition, and arranged in a vague storiform pattern with scattered lymphoplasmacytic aggregates. These features led to a variety of diagnoses, including benign inflammatory and fibrohistiocytic lesions (13 cases) as well as lymphoma and malignant fibrous histiocytoma (three cases). RDD was correctly diagnosed in only one case. Diagnosis was confirmed in 16 of 18 lesions by detection of S-100 protein and histiocytic markers KP1 (12 of 13) and lysozyme (eight of 11) in the characteristic histiocytes. Recognition that RDD of soft tissue occurs in an older patient population than does nodal RDD and that it mimics fibrous and inflammatory lesions of soft tissue is important.     

The use of fresh tissue arterial substitutes in infected fields.

An experiment, designed to test the efficacy of arterial bypass in the presence of infection using fresh autograft and allograft arteries in comparison to knitted Dacron grafts is presented. Three months following implantation of these conduits in infected femoral wounds, 11 out of 12 autografts, and 10 out of 12 allografts were found to be sterile, while 7 out of 8 Dacron grafts were infected. The results of this study suggest that fresh, live arterial autograft and allograft arteries are suitable materials for arterial reconstruction in infected fields since they function as a vascular conduit and allow the clearing of the infectious process by conventional antibiotic therapy.     

Clinical features of soft tissue sarcomas.

The presenting features of 526 patients referred to an open access 'lumps and bumps' clinic were reviewed to try and identify whether the four cardinal features of soft tissue malignancy were in fact predictive of this. The features investigated were: size bigger than 5 cm, pain, increase in size, depth beneath the deep fascia. All of these factors were found to be associated more frequently with malignancy than a benign state. Using the summed weights of evidence method we have constructed a graph which will allow prediction of whether a lump is likely to be malignant or not.     

The diagnosis of soft tissue tumours.

We prospectively analysed methods of diagnosis in 118 patients referred for definitive treatment with documented or presumed soft tissue sarcoma (STS). Of 65 patients with primary STS, 54 were biopsied before referral. Of these, 5 (9%) were biopsied by Tru-cut biopsy, 17 (32%) by incisional biopsy and 32 (59%) by excisional biopsy. The remaining 11 patients with primary STS, referred without biopsy, were all diagnosed by Tru-cut biopsy. An additional eight patients suspected of having STS were referred without biopsy and were found to have malignant tumours other than STS involving soft tissue by Tru-cut biopsy. Nineteen patients were proved to have benign soft tissue tumours; in 13 presumed to have STS, the diagnosis was unknown at referral. In four of these, biopsy was inappropriate. Of nine submitted to Tru-cut biopsy, an unequivocal diagnosis was made in 5 (56%) and incisional biopsy was required in the other four. Therefore, paradoxically, benign soft tissue tumours may be more difficult to diagnose with Tru-cut biopsy than malignant tumours. This study confirms the high degree of accuracy of Tru-cut biopsy in diagnosing malignant soft tissue tumours and highlights the disadvantages of open biopsy techniques.