PubMed HealthSearch

Biomedical subjects

K E Marks

Publications and source records attributed to K E Marks.

At least 19 recordsLinked to original sources

Juxta-articular osteoid osteoma.

Osteoid osteomas that arise at the end of a long bone, within the insertion of the joint capsule (juxta-articular, intra-articular), may cause misleading clinical, radiographic, and histologic findings, resulting in unnecessary diagnostic tests and a delay in definitive treatment. To clarify optimum diagnostic procedures, we reviewed 20 cases of juxta-articular osteoid osteomas and found a mean delay from presentation to correct diagnosis of 24 months. Plain radiographs were either negative or showed only secondary changes. A periosteal reaction and proliferative synovitis with chronic inflammation was common, which could be misinterpreted as rheumatoid arthritis. Optimum diagnostic procedures were a bone scan followed by plain tomograms and an excisional biopsy of the nidus.

Adolescent

Ki-67 and grading of malignant fibrous histiocytomas.

Although generally considered to be of high grade, malignant fibrous histiocytomas (MFH) show a range of histologic appearances and a diverse biologic behavior. More precise grading of this type of sarcoma is desirable. The rate of cell proliferation may reflect clinical behavior. A more sensitive measure of cell proliferation is the expression of the Ki-67 antigen. Frozen sections were prepared from 29 cases of MFH. Sections were immunohistochemically stained for Ki-67, and the results were quantitated by image analysis (CAS 100). The Spearman rank correlation test was used to compare the extent of the Ki-67 staining with the conventional histologic grade, nuclear grade, number of mitoses, extent of necrosis, and overall cellularity. There was a significant correlation between the extent of Ki-67 staining and the nuclear grade (cc = 0.56; P = 0.002) and overall histologic grade (correlation coefficient = 0.58; P = 0.001), but there was no significant, independent correlation between Ki-67 and prognosis.

Adult

Expandable breast implant reconstruction of Tikhoff-Linberg shoulder deformity.

Expanding breast implants were used in two patients to reconstruct shoulder contour following a Tikhoff-Linberg resection for cancer. In the first patient, one implant alone was used, and in the second patient, two implants in separate but adjacent pockets. The resulting double contour is more pleasing than that after a single implant, and there also appears to be more flexibility with shoulder motion. This method is suggested as an excellent means of reconstructing the contour of the shoulder area following resection for cancer.

Breast

Vancomycin vs tobramycin elution from polymethylmethacrylate: an in vitro study.

We fabricated batches of cement containing 0.5 gm, 1.0 gm, and 2.0 gm vancomycin and one with 1.0 gm tobramycin and shaped them into cylinders. They were immersed into 0.5 L of normal saline and the fluid volume was changed daily. Samples of fluid were obtained on days 1, 2, 3, 5, 7, 14, and 28. All fluid samples had antibiotic assays performed to quantitate the amount of elution for vancomycin or tobramycin. Vancomycin elution from PMMA occurred under our study conditions in similar quantities to that measured for tobramycin controls. Vancomycin-loaded PMMA cement may have a clinical role in the treatment of musculoskeletal sepsis caused by gram-positive bacteria, particularly if organisms resistant to the usual antibiotic agents are identified.

Biomechanical Phenomena

Fibrous tumors of bone.

Benign and malignant fibrous tumors of bone are some of the most common tumors encountered by the orthopedic surgeon. Fibrous dysplasia, fibrous cortical defect, non-ossifying fibroma, benign fibrous histiocytoma and osteofibrous dysplasia are benign tumors best treated conservatively or by intralesional/marginal excision. Desmoplastic fibromas are locally aggressive and require a wide margin for surgical cure. Malignant fibrous histiocytoma and fibrosarcoma of bone are malignant bone tumors and must be treated with wide/radical margins and for malignant fibrous histiocytoma adjunctive chemotherapy.

Bone Neoplasms

Fast axonal transport in amyotrophic lateral sclerosis: an intra-axonal organelle traffic analysis.

Fast transport of intra-axonal organelles was studied in motor nerve from amyotrophic lateral sclerosis (ALS) patients. Organelle traffic in ALS nerves demonstrated a significant increase in anterograde mean speed, while retrograde mean speed was decreased compared with that of controls. Retrograde traffic density (organelles per unit time) was also significantly decreased in the ALS specimens. Anterograde transport machinery is therefore intact and may be responding to the increased physiologic demand of larger motor units. Diminished retrograde speed and organelle traffic density are consistent with a defect in retrograde transport and could impair communication between axon terminals and perikarya.

Amyotrophic Lateral Sclerosis

Intraneural lipoma of the sciatic nerve.

A large, well-encapsulated intraneural lipoma occurred within the sciatic nerve of a 34-year-old woman. In a review of the literature, significant differences were noted between the well-encapsulated and the diffusely infiltrative lipofibromatous hamartoma types of intraneural lipomas. The average age at the time of appearance of the well-encapsulated type is 45 years, with female predominance, while the infiltrative type arises in a younger age group (average age, eight years) with no sexual predominance. To avoid a recurrence, total excision is recommended in cases of the well-encapsulated type. Attempts to excise the diffusely infiltrative type are likely to fail.

Adult

Periosteal Ewing's sarcoma.

Ewing's sarcoma is a small cell malignant tumor that usually arises in the medullary cavity of bone. Less frequently, it originates in soft tissue and may secondarily invade underlying bone. The origin of Ewing's sarcoma in a periosteal location without extension into either the bone or adjacent soft tissue has not been clearly documented. Other malignant tumors of bone (e.g., osteosarcoma) appear to have a somewhat better prognosis when confined between periosteum and bone. The case of a patient with a periosteal Ewing's sarcoma who received a radical excision and postoperative chemotherapy and who is without evidence of disease with over 2 years follow-up is reported.

Adolescent

Digital subtraction angiography for preoperative evaluation of extremity tumors.

A retrospective study was undertaken to evaluate the role of digital subtraction angiography (DSA) in the surgical planning of musculoskeletal neoplasms. Thirteen patients with primary bone and soft-tissue tumors were examined by CT and DSA. Three patients also had conventional angiography. DSA yielded surgically useful information in 10 patients, comparable to that expected from conventional angiography. DSA was most helpful in demonstrating the presence or absence of major vessel involvement by tumor when this could not be ascertained definitely on CT. Demonstration of mass extent by CT was accurate in 11 patients. Results of this study suggest that the combination of CT and DSA is useful in the preoperative evaluation of selected extremity tumors and should diminish the need for conventional angiography.

Angiography

A ten-year follow-up of one hundred consecutive Müller curved-stem total hip-replacement arthroplasties.

One hundred consecutive Müller curved-stem total hip replacements were reviewed ten years after operation. Twenty patients with twenty-two arthroplasties had died within the ten-year period without having a revision, and twenty-five arthroplasties had been revised for various reasons. Of the remaining fifty-three arthroplasties, thirty-five were classified as good or excellent, with Harris hip scores of 80 points or higher, and eighteen were classified as poor or fair, with scores lower than 80 points. Follow-up radiographs, made for all but six of the fifty-three hips at ten years, showed a 23 per cent incidence of migration of the acetabular component and a 28 per cent incidence of migration of the femoral component. In addition, there was a 15 per cent incidence of bone resorption in the proximal end of the femur without migration of the femoral component and a 4 per cent incidence of osteolytic defects about the femoral component, also without migration. Combining the radiographically loose replacement (migration) with the clinically loose ones (revised), the over-all incidence of aseptic loosening was 29 per cent for the acetabular component and 40 per cent for the femoral component. There was a positive correlation between the incidence of loosening of the femoral component and younger age, heavier weight, male sex, unilateral hip disease, a wide femoral canal, and varus position of the femoral component, whereas the incidence of loosening of the acetabular component was increased only in association with older age. The rate of loosening of the femoral component appeared to be higher during the early follow-up period and to decrease with time, while the rate of loosening of the acetabular component appeared to be lower during the early follow-up period but to increase with time.

Adult

Cutaneous complications of orthopedic implants. A two-year prospective study.

In a two-year prospective study of cutaneous problems in orthopedic implant recipients, cutaneous eruptions of unknown cause that bore good temporal relationships with implant surgery occurred in 19 patients. Two clinical patterns were observed. A transient "exanthematic" dermatitis was seen in six patients; in two of them, it recurred after each surgical implant procedure. A persistent reaction was seen in 13 patients. Metal sensitivity was found in two patients and considered to be relevant. Allergic cutaneous complications of orthopedic implants are rare. However, in an implant recipient in whom a cutaneous problem develops, the likelihood of the cutaneous problem being allergic in nature is slightly greater if the implant is of the static type, if there is a history of metal sensitivity, if the cutaneous eruption shows a predilection for the anatomic zone of the implant, and if the eruption is eczematous and has developed late and persisted.

Adult

Patella alta and chondromalacia.

The Insall-Salvati method of determining the position of the patella by radiography was employed in fifty-one patients with chondromalacia patellae that had been proved at arthrotomy. There was no definite relationship between chondromalacia patellae and patella alta. There was, however, a highly significant statistical difference between the ratio of the length of the patella to that of the patellar tendon in normal men and women.

Adolescent

Mechanical strength of acrylic bone cements impregnated with antibiotics.

Admixing of several antibiotic powders which were insoluble in methyl methacrylate did not decrease the compressive and diametral tensile strengths of two acrylic bone cements when tested after setting for 1 day and after leaching 40 days in water at 37 degrees C. When antibiotics were added as water solutions, the included water resulted in a significant decrease in these bulk mechanical properties. Storage in water for 40 days caused surface irregularities only on specimens of the set antibiotic admixtures. Approximately 0.5% of the admixed dosage of these water-soluble antibiotics could be leached from the set cements. The observed surface channels, presumably left by the loss of antibiotic, suggest further study of surface-sensitive mechanical properties may be needed. The bulk mechanical strengths presented here are conclusive only for the particular combinations of antibiotics and cements investigated, and should not be generalized at this time to any or all antibiotic admixtures or other mechanical properties.

Anti-Bacterial Agents