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Biomedical subjects

M H Meyers

Publications and source records attributed to M H Meyers.

At least 19 recordsLinked to original sources
PubMed1994

Chondral defects of the knee.

The surgical treatment of a young adult with a localized defect in the articular cartilage of the knee most commonly employs arthroscopic shaving and/or subchondral drilling. Fresh osteochondral allografting is an alternative that is being performed with increasing frequency. As of June 1993, fresh osteochondral allografts have been used in 90 knees in our institution. Thirty-eight of these knees have been evaluated two or more years postoperatively, and a successful result was obtained in 76%. If the lesion was confined to the medial condyle, the success rate was 86%, but when both reciprocal surfaces were replaced (bipolar) the success rate was 56%.

Adolescent↗
PubMed1991

Fresh osteochondral allografting of the femoral condyle.

Fresh osteochondral shell allografting is conceived as an interim response to the localized loss of articular cartilage in young patients for whom there is no reasonable alternative after conservative procedures have failed. The concept is not new and has been investigated extensively in in vivo animal investigations. The functional and anatomic results of these studies, however, have been consistently unsatisfactory because of technical deficiencies and supposed immunogenic responses. The results of early clinical studies were variable, and despite more recent clinical work, the procedure has been considered at least investigational by some. The purpose of this study is to retrospectively review a series of patients treated with osteochondral allografting of the femoral condyle with particular emphasis on those done more than five years ago. No tissue-typing blood-group matching or gender distinction was made and immunosuppressant agents were not used. Size matching of the donor and recipient were essential to provide an orthotopic graft. Twelve knees were operated on more than five years ago. Of these twelve, three are not available for review. Nine knees have been observed for an average of 66 months and eight are rated good or excellent by a standardized rating scale. One knee rated poor seems to be the result of a technical deficiency. Since 1983, 37 fresh osteochondral allografts of the femoral condyle have been performed in 36 patients. Twenty-five of these have been performed in the last five years and the results to date are summarized.

Adolescent↗
PubMed1990

Long-term storage effects on canine osteochondral allografts.

We have studied long-term (to 60 days) effects of 4 degrees C storage in culture media on the histologic, mechanical, and chemical properties of the cartilage from osteochondral shell allografts from the dog. The structural integrity of the cartilage matrix was intact up to 60 days of storage, for the mechanical properties represented by the aggregate modulus and apparent permeability remained normal. These data are supported by normal safranin-O staining as well as normal glycosaminoglycan content and total collagen concentration. However, chondrocyte viability, as assessed by 35SO4 uptake and hematoxylin and eosin preparations, decreased dramatically with time. We believe that the longer storage to 60 days is not indicated, unless conditions can be modified to maintain cell viability.

Animals↗
PubMed1990

Acetabular augmentation in primary and revision total hip arthroplasty with cementless prostheses.

Twenty-four consecutive cementless hip arthroplasties (13 autografts and 11 allografts) have been done in which large bone grafts were used to augment major acetabular deficiencies and have been followed for a minimum of 24 months with a mean of 34 and a maximum follow-up period of 55 months. The autograft augmentations were uniformly successful. Two fixation failures occurred in the allograft group. Considering the extreme deficiency in the acetabulae encountered and the absence of sufficient autograft material in this group of patients, the use of frozen allografts (although less successful in this series) seems justified. Graft resorption as determined by direct roentgenographic measurements was less than might be expected but may be a manifestation of the short-term follow-up period. Resorption, however, was greater in the allograft group and, when marked, was associated with fixation failure.

Acetabulum↗
PubMed1989

Resurfacing of the knee with fresh osteochondral allograft.

Fifty-nine fresh osteochondral allografts were consecutively transplanted into the knees of fifty-eight patients. The preoperative diagnoses were chondromalacia or degenerative arthritis of the patella, osteochondritis dissecans, a traumatic defect or osteonecrosis of the femoral condyle, a painful healed depressed fracture or traumatic defect of the tibial plateau, and unicompartmental traumatic arthritis of the knee. All of the patients had disabling pain after the failure of previous attempts to correct the problem surgically. Thirty-nine patients (forty knees) were available for follow-up at two to ten years after the allograft was transplanted. Nine transplants (22.5 per cent) failed and thirty-one (77.5 per cent) were successful. The result was rated excellent after thirteen of the successful transplants, good after fourteen, and fair after four. Transplantation of a fresh osteochondral allograft proved to be a satisfactory intermediate procedure for the treatment of the disabling conditions, except unicompartmental traumatic arthritis, in the young patients in this series. For the patients who had unicompartmental traumatic arthritis, the rate of success was only 30 per cent.

Adolescent↗
PubMed1988

Osteonecrosis of the femoral head. Pathogenesis and long-term results of treatment.

Except after trauma resulting in an intracapsular fracture of the femoral neck or dislocation of the hip, the causes of pathogenesis in osteonecrosis of the femoral head have yet to emerge. The circulation to the femoral head may be impaired severely following a traumatic episode. Staging of the pathologic process is important as the selection of the appropriate surgical treatment depends upon the stage at the time of diagnosis. Anteroposterior and lateral roentgenograms are sufficiently accurate to make the diagnosis in Stages II to V. Tomography or Magnetic Resonance Imaging (MRI) are prescribed when roentgenograms are consistent with Stage II disease. This recommendation is made because subtle changes may be present that are not apparent on the roentgenogram, such as fracture of the surface or beginning segmental collapse. These changes would change the classification to Stage III rather than Stage II. MRI or core biopsy is required for diagnosis in Stage I. Many surgical treatment options have been proposed for the treatment of osteonecrosis of the femoral head. No one operation has been shown to be superior. Most papers do not have sufficient long-term follow-up evaluation or a significantly large number of cases to allow one to draw firm conclusions about the efficacy of the operation. Total hip replacement or hip arthrodesis is the treatment of choice for the end stages of the disease when the hip joint has degenerated.

Bone Transplantation↗
PubMed1987

Radiographic evaluation of joints resurfaced with osteochondral shell allografts.

The radiographic features of 41 cadaveric osteochondral shell (low ratio of subchondral bone to articular cartilage) allografts placed in 24 patients for articular resurfacing as an alternative to arthroplasty are presented. Underlying causes of joint disease included ischemic necrosis (20 grafts), osteochondritis dissecans (nine), chondromalacia patellae (10), and posttraumatic osteochondral fracture with degenerative disease (two). Congruity with the adjacent native articular surface and the opposite side of the joint was evident on immediate postoperative radiographs in all patients, and proved to be critical to the ultimate success of the procedure. On follow-up radiographs over a period of 2-28 months, successful incorporation of the allograft was characterized by progressive loss of the relative increased density of the graft, in association with diminished lucency related to new bone formation at the graft-native bone interface, as well as maintained alignment. Graft failure was associated with positional changes including collapse, persistent increased density, and poorly defined fragmentation that occasionally simulated infection radiographically and resulted in intraarticular bodies. Resurfacing of diseased articulations with osteochondral shell allografts constitutes a potentially desirable alternative to total joint arthroplasty, particularly among younger patients. Consequently, an awareness of the expected radiographic alterations associated with graft incorporation and failure is important.

Adolescent↗
PubMed1985

Osteonecrosis of the femoral head treated with the muscle pedicle graft.

The pedicle graft of the quadratus femoral muscle has been a satisfactory surgical alternative for the treatment of osteonecrosis of the femoral head. The relief of pain within a few days or weeks of the operation and the absence of further destructive changes in the femoral head leading to segmental collapse have been striking in patients meeting the criteria that make them candidates for this operation. Whether the muscle pedicle operation will have a permanent beneficial effect remains to be seen.

Adult↗
PubMed1983

Fresh autogenous grafts and osteochondral allografts for the treatment of segmental collapse in osteonecrosis of the hip.

The treatment of femoral head osteonecrosis and segmental collapse with fresh autogenous grafts and osteochondral allografts is in the experimental stages. The early results suggest that the grafts may be a satisfactory intermediate conservative alternative to radical surgery. Strict adherence to the criteria for selection of candidates for grafting and meticulous surgical technique are essential prerequisites if optimal results are to be achieved. Factors favoring the choice of autologous or allogeneic grafts in osteonecrosis of the hip are the clinically insignificant immunologic reaction and viable hyaline cartilage. Immunosuppressive agents are nonessential. Failure does not preclude artificial resurfacing, endoprosthetic replacement, or total hip arthroplasty.

Adolescent↗
PubMed1983

Surgical treatment of osteonecrosis of the femoral head.

Until the cause of femoral head osteonecrosis is understood and preventive treatment devised, surgery is the best treatment available. Early recognition and surgical treatment in the beginning stages offers the best hope for salvaging the diseased femoral head. Osteotomy, allograft, and autograft techniques may prove to be successful salvage procedures in advanced stages (III and IV). Failure of the salvage procedures requires artificial replacement surgery, which is less than ideal.

Biopsy↗
PubMed1983

Avascular necrosis of the femoral head--diagnostic techniques, reliability and relevance.

Diagnosis of avascular necrosis in the early stages (I and II) offers the opportunity to prevent late segmental collapse and secondary degenerative arthritis of the hip through early surgical intervention. Functional bone marrow studies and core biopsy are the simplest and best tests for diagnosing avascular necrosis of the hip. Bone scans are helpful in diagnosis and provide supportive evidence. Routine roentgenography and occasionally tomography are the only tests required for diagnosis in advanced stages of the disease.

Biopsy↗
PubMed1982

Pitfalls in simple fracture care.

Many errors in diagnosing simple fractures are made because of inadequate roentgenography and inexperience in interpretation. Two views are almost always needed, and in some cases more. An x-ray film of the opposite uninjured extremity may be helpful for comparison. In many instances, stress views can differentiate bone injury and ligament injury. The first physical examination after injury must be thorough, with a search for peripheral nerve injury and vascular injury. A cast should not be used if certain conditions are present, eg, severe dermatitis, circulatory problems, venous insufficiency, paraplegia. When applying a cast, care must be taken to position the body structure correctly, include only the joints necessary, avoid too tight application, and choose the proper cast length. Prolonged immobilization can result in joint stiffness or even disability. The patient should be warned about danger signals, such as pain, numbness, and cyanosis, and should be monitored regularly for complications.

Blood Vessels↗
PubMed1980

The role of posterior bone grafts (muscle-pedicle) in femoral neck fractures.

Mastering the muscle-pedicle technique and adhering to the principles of accurate reduction, impaction of the fracture fragments, and secure fixation should result in significant improvement in the rate of osseous union and marked reduction in late segmental collapse after treatment of displaced femoral neck fractures.

Adult↗
PubMed1979

Closed biopsy of musculoskeletal lesions.

Five hundred and thirty-one closed biopsies have been done in our general hospital since 1967. Four hundred and eighty-four were for lesions of bone and forty-seven were for soft-tissue lesions. More than half of the lesions were infections or nonspecifically reactive. The procedure was done under local anesthesia in 73 per cent and roentgenographic or image-intensifier control was generally required. The Craig needle was used for cancellous bone near vital structures; the Michele trephine, for cortical or sclerotic bone at a distance from vital structures; and a special needle was used for soft tissue. Closed biopsy provided an adequate specimen that was accurately diagnosed in 66 per cent of bone lesions and in 76 per cent of soft-tissue lesions. This compared favorably with both aspiration and open-biopsy success rates reported by others, and was accompanied by a 1 per cent complication rate, mostly neural and mostly in association with vertebral lesions.

Biopsy↗