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Biomedical subjects

F Langer

Publications and source records attributed to F Langer.

At least 73 records · Page 4Linked to original sources
PubMed1988

Bone banks and allografts in community practice.

The increasing volume of orthopaedic reconstructive procedures requiring replacement of bone stock justifies the initiation of programs of bone banking in community hospitals. Provided that strict criteria are followed to assure rigorous screening of donor bone and the reliable preservation of bone graft material, community banking is safe and cost-effective. Banked allograft bone can be used successfully in a wide variety of orthopaedic procedures performed in community hospitals. In general, the best uses are filling bone cavities, buttressing, and augmenting the quantity of autograft bone. In revision reconstructive surgery of the hip, bank bone is used to replace bone stock in protrusio, acetabular dysplasia, and proximal femoral deficiency. The best and most common indication for the use of bank bone in tumor surgery is after curettage or excision of benign lesions. Allografts may be used to reconstruct bony defects after excision of malignant tumors and in the surgical treatment of metastatic disease. These instances require larger bone bank facilities than those commonly available in a community hospital setting. Medicolegal considerations related to bone banking and the use of allografts in community practice include the regulatory requirements outlined in the UAGA, questions concerning negligence liability, and theories of strict product liability. Overall, good medical practice and obtaining informed consents will minimize legal risks related to bone banking and transplantation in a community setting.

Bone Transplantation↗
PubMed1988

Guidelines for the surgical management of soft-tissue sarcoma. Report of the Canadian Sarcoma Group.

The Canadian Sarcoma Group was formed in 1985 by interested surgeons, oncologists and pathologists. In the evaluation of new protocols, standard surgical guidelines have been developed which incorporate the concepts of multimodality therapy, particularly radiotherapy and chemotherapy. Also defined are the procedures performed: biopsy, marginal resection, wide local excision, radical resection and the principles to be considered when doing a diagnostic biopsy and a curative resection, particularly with limb salvage in mind. To optimize local control of the disease, centres treating sarcomas should have access to computed tomography, radionuclide scanning, to radiation and medical oncologists, and members of other surgical specialties. This team approach increases survival by 10% and also provides the best circumstances in which to study adjuvant therapy. Surgical guidelines are also essential in order to compare the results of different clinical trials.

Biopsy↗
PubMed1986

Bone and cartilage allotransplantation. A review of 14 years of research and clinical studies.

The authors review their experience of over 14 years in the field of osteochondral allotransplantation. Experimental studies demonstrated the immunogenicity of bone and cartilage, immunosuppression in skeletal transplantation models, and a subset of myeloid cells within bone marrow with strong immunogenic properties. Clinical results of knee joint resurfacing with fresh small-fragment osteochondral allografts have been best in posttraumatic joints. Experience with allograft reconstructions of skeletal defects after tumor surgery has been gratifying as a limb salvage procedure. Microvascular fibular autografts have been an important adjunct in massive reconstructive osteochondral transplantation.

Animals↗
PubMed1985

Osteochondral allografts in the treatment of osteonecrosis of the knee.

In summary, patients with spontaneous osteonecrosis of the knee requiring surgery were elderly and generally had late stage IV disease. They seemed to do better with osteotomy and debridement than with osteochondral allograft replacement because they could not tolerate restricted weight bearing. Patients with steroid-induced osteonecrosis did well initially after allograft replacement (6 to 18 months), especially in experiencing pain relief. However, because of the continuous use of high doses of steroids, revascularization of the allografts was poor, resulting in graft subsidence. Patients have better long-term results following osteotomy and debridement. Patients with traumatic osteonecrosis and osteochondritis dissecans had the best results following osteochondral allograft replacements. In conclusion, based on our series and others, our current surgical approach in the management of osteonecrosis of the knee is as follows: 1. In patients with spontaneous osteonecrosis with asymptomatic small lesions, nonsurgical treatment is recommended. For an asymptomatic or symptomatic large lesion with associated angular deformity, the active patient should have a tibial osteotomy for stages I and II and tibial osteotomy and debridement for stages III and IV. Less active patients with symptomatic stage III or IV disease should have unicompartmental or total knee prosthetic arthroplasty. 2. For steroid-induced osteonecrosis, osteochondral allografts are not recommended. If the patient's systemic disease has a limited prognosis, or if the patient has multijoint involvement, total knee or unicompartmental arthroplasty is warranted. If the patient has a good prognosis and is active, debridement with or without realignment should be performed. 3. For traumatic osteonecrosis in the younger patient or for osteochondritis dissecans, fresh osteochondral allograft replacement is recommended. High tibial osteotomy in combination with allograft replacement should also be done if there is associated malalignment. The realignment should be done prior to or simultaneously with the allograft (providing the osteotomy is done on the side of the joint opposite the allograft).

Adolescent↗
PubMed1984

The pathologic features of massive osseous grafts.

The authors studied histologically six of 35 massive osseous or osteochondral transplants that had been inserted following radical resection of musculoskeletal malignancies. The six transplants consisted of three allografts removed because of infection within 12 weeks following insertion and two allografts and one vascularized autograft resected between 52 and 72 weeks because of recurrent tumor. The infected allografts were necrotic and showed extensive osteomyelitis and septic arthritis. Focal areas of cartilage still had chondrocytes. The two non-infected allografts were also necrotic, and host bone had grown into donor bone at the graft--host interface. The vascularized autograft was viable. Articular cartilage was present in only one of the non-infected allografts and was necrotic. Ultrastructurally, allograft cartilage, although necrotic, showed marked destruction of the matrix only when infected. Allograft bone seems to act purely as a strut, inciting little immune response. It is unable to respond to infection and has little osteoinductive ability. Vascularized autograft, in contrast, appeared to contribute to graft union. Articular cartilage can survive transplantation but may become necrotic and undergo marked degeneration when infected. The histologic findings and clinical courses support the conclusion that graft failure within 72 weeks after transplantation is not due to immunologic rejection.

Adult↗
PubMed1984

Late osteochondral allograft resurfacing for tibial plateau fractures.

Seventeen patients in whom secondary degenerative arthritis developed after a tibial plateau fracture underwent osteochondral allograft resurfacing of the involved plateau. The transplantation was done within twenty-four hours of procurement of the allograft from a cadaver donor so that viable cartilage would be used. There were sixteen tibial resurfacing grafts, and one patient had a tibial and femoral graft. Twelve patients have been followed for more than two years. A rating system for pain and function showed marked improvement in ten of the twelve patients. The clinical results were not related to age, interval from injury to grafting, type of graft, length of follow-up, or radiographic data. We believe that appropriate selection of patients for the procedure was the factor that led to the best results. Collapse of the osseous portion of the graft measuring more than three millimeters occurred in two patients, and there was obliteration of the cartilaginous joint space in one patient. This method of joint resurfacing requires minimum resection of tissue and avoids the use of a prosthesis. The ultimate fate of these grafts is not known, but the results in our series were encouraging. however, at this time the procedure should be restricted to younger patients with disabling, localized post-traumatic arthritis.

Adult↗
PubMed1983

Vascularized limb transplantation in the rat. I. Results with syngeneic grafts.

A microsurgical model was developed to study the transplantation of large sections of vascularized skeletal tissue in inbred rats. A modified vascularized leg graft, consisting of the distal femur, knee joint, and intact tibia, with the associated musculature, was orthotopically transplanted in Fischer F344 rats. The femoral artery and vein were anastomosed by means of a microsurgical technique. Skin coverage was accomplished with recipient skin. In the studies reported here, syngeneic grafts were followed for up to twelve months by means of clinical examinations, X-rays, bone scans, and histologic studies. The bone and joint tissues not only survived but grew; the joints functioned and appeared to be histologically normal. Nonvascularized control grafts rapidly developed necrosis and osteomyelitis that lead to death of the recipients. Nonvascularized knee joint grafts, which were performed as additional controls, were better tolerated than nonvascularized limb grafts but they developed progressive degenerative changes. Thus, only the vascularized grafts restored optimal limb function. This model will be useful for exploring the feasibility and potential uses of large vascularized grafts of skeletal tissue.

Angiography↗
PubMed1983

Reconstruction of skeletal deficits at the knee. A comprehensive osteochondral transplant program.

From 1971 to 1982, 110 osteochondral transplants with follow-up evaluation were performed for treatment of skeletal deficits caused by degenerative, traumatic, and neoplastic diseases largely involving the knee joint. Seventy-eight small-fragment fresh allografts were transplanted for repair of old tibial plateau osteochondral fractures, osteonecrosis, and unicompartmental osteoarthritis. Thirty-two large-fragment grafts were performed following en bloc excision of bone tumors. Of these, 22 were allografts, three were vascularized fibular autografts, and seven were a combination of allografts and vascularized fibular autografts. In this large-fragment group, three grafts have been removed for tumor recurrence, two for infection, and one for a stress fracture. The results of these transplants have proved particularly rewarding in the old plateau fractures, for traumatic loss of bone and cartilage (osteonecrosis), and after en bloc excision of giant cell tumors.

Adolescent↗
PubMed1982

Giant cell tumor associated with trauma.

Presented is a case report of a 19-year-old man who developed a giant cell tumor in the distal ulna following trauma to the carpus. Roentgenograms and bone scan revealed a fracture of the scaphoid and no other bony abnormalities. On year later, after the scaphoid fracture had healed, the same investigations demonstrated a giant cell tumor of the distal ulna. Circumstantial evidence suggests a possible role for trauma in the pathogenesis of giant cell tumor.

Adult↗
PubMed1982

Radical radiotherapy as primary treatment for Ewing's sarcoma distal to the elbow and knee.

This article is a review of 22 cases of Ewing's sarcoma peripheral to the elbow and knee treated with moderate dose radiotherapy, with special reference to local control, functional result and risk of irradiation induced sarcoma. Eleven patients (50%) are alive two to 16 years following radiotherapy. Two of these had local recurrences, one being salvaged by reirradiation and the other by amputation. The functional results of treatment were assessed in the nine survivors who did not have a recurrence . Eight had normal limb function and one had a 3 cm leg-length discrepancy. Nine patients in the total experience of the hospital who survived more than ten years after radiotherapy were assessed for evidence of postirradiation sarcoma and none were found. The excellent results of radiotherapy in terms of local control, function and lack of irradiation induced sarcomas is attributed to the use of moderate doses of irradiation.

Adolescent↗
PubMed1981

Fracture of the atlas associated with fracture of the odontoid process.

A case of burst fracture of the atlas associated with a type II fracture of the odontoid is presented. In this instance no atlanto-axial instability was detected clinically. Treatment consisted of 1 week of rest in bed followed by 3 months in a collar. Management, though conservative, resulted in full recovery.

Adult↗
PubMed1981

Bone scanning in assessing viability of vascularized skeletal tissue transplants.

One hundred and eight bone scans using 99mTechnetium methylene diphosphonate (MDP) were performed in rats undergoing vascularized and nonvascularized syngeneic and allogeneic transplants of the hind limb, and in control animals. A six-level system of grading the radionuclide uptake in the graft was used to evaluate healing or complications of the transplantation. Bone scanning was superior to other modalities in assessing viability of the graft. Bone scans were able to: (1) immediately confirm vascular patency, thus obviating angiography; (2) demonstrate differences in the rate of repair in syngeneic and allogeneic nonvascularized grafts; (3) sequentially assess vascularized allograft rejection; and (4) document long-term effects, such as bone atrophy due to disuse and early epiphyseal maturity.

Animals↗