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Biomedical subjects

C L Nelson

Publications and source records attributed to C L Nelson.

At least 91 records · Page 5Linked to original sources
PubMed1991

Retrospective analysis of 135 secondary alveolar cleft grafts using iliac or calvarial bone.

This retrospective study summarizes experience with 135 secondary alveolar cleft bone graft procedures over 8 years. The overall success rate was 83.7%. The group of patients (n = 108) that had particulate cancellous bone and marrow obtained from the iliac crest as donor bone had an 89.8% success rate. The group (n = 27) that had calvarial bone as the donor material had a success rate of only 63%. It is felt that inferior results with calvarial bone are probably related to the procurement technique. In both the iliac crest and calvarial groups, there was a trend toward declining success rates with advancing age of the patient. Morbidity associated with these procedures, consistent with other reported series, was low.

Adolescent↗
PubMed1991

Restenosis after coronary angioplasty: an overview.

Despite substantial basic and clinical efforts to address the problem of restenosis after percutaneous coronary intervention, effective preventive therapies have not yet been developed. Nevertheless, the accumulated information has provided much insight into the process of restenosis in addition to allowing standards to be developed for adequate clinical trials. The pathophysiology of restenosis increasingly appears to be distinct from that of primary atherosclerosis. Restenosis involves elastic recoil, incorporation of thrombus into the lesion and fibrocellular proliferation in varying degrees in different patients. Lack of an animal model that satisfactorily mimics restenosis is a major impediment to further understanding of the process. Clinical studies are hampered by difficulties in finding a single unifying definition of restenosis and by variable methods of reporting follow-up. Reporting of clinical outcomes of all patients in angiographic substudies would allow a more satisfactory interpretation of the results of clinical trials. Current noninvasive test results are not accurate enough to substitute for angiographic and clinical outcome data in intervention trials. In the majority of observational studies, only diabetes and unstable angina have emerged as consistently associated with restenosis; whereas most of the standard risk factors for atherosclerosis have a less consistent relation. Disappointingly, the new atherectomy and laser technologies have not affected restenosis rates. The one possible exception is coronary stenting, as a result of the larger luminal diameter achieved by the placement of the stent. In conclusion, although substantial continued effort is necessary to explore the basic aspects of cellular proliferation and mechanical alteration of atherosclerotic vessels, attention to the principles of clinical trials and observation are required to detect the impact of risk factors and interventions on the multifactorial problem of restenosis. Adequate sample sizes, collection of clinical and angiographic outcomes and factorial study designs hold promise for unraveling this important limitation of percutaneous intervention.

Angioplasty, Balloon, Coronary↗
PubMed1991

Duplex scanning in orthopaedic patients.

Duplex scanning with a combination of real-time and Doppler ultrasound is a noninvasive procedure used for the detection of deep vein thrombosis. The technique is described, its use in orthopaedic patients is discussed, and a plan of treatment based on duplex results is reported.

Arthroplasty↗
PubMed1991

Cup arthroplasty, surface replacement arthroplasty, and femoral head resurfacing for osteonecrosis.

Traditional cup arthroplasty and resurfacing arthroplasty of the femoral head and acetabulum have been proposed as bone-conserving procedures for avascular necrosis of the hip. Resurfacing of only the femoral head is not a definitive procedure but is an alternative to cup arthroplasty and resurfacing arthroplasty of the femoral head and acetabulum; hemiarthroplasty is recommended for the young patient with intact acetabular cartilage. Indications, technique, and clinical results are presented.

Femur Head↗
PubMed1991

Hemifacial microsomia: assessment of classification systems.

Hemifacial microsomia (HFM) represents a spectrum of congenital malformations involving embryological derivatives of the first and second branchial arches. The multiple anomalies that may exist in HFM present considerable variability in patients with the diagnosis. Numerous classification systems have been devised to facilitate the individualized components of this complex condition. Because multiple HFM classification systems exist, their utility is frequently confusing and selection of a particular system is indeterminate. Several of the better known systems are evaluated using patients with variable expressivity of HFM. This review suggests that there currently exists no ideal classification system for this association of developmental malformations. The systems that were found to be most complete are acknowledged and recommendations or modifications are suggested.

Abnormalities, Multiple↗
PubMed1991

Duplex scanning versus venography as a screening examination in total hip arthroplasty patients.

Combined B-mode/Doppler (duplex) scanning and venography were compared in routine perioperative screening for proximal deep vein thrombosis (DVT) in 158 total hip arthroplasty (THA) patients. Preoperative scans were performed in the first 60 patients; the low preoperative prevalence of 2% for proximal DVT was thought not to warrant routine preoperative scanning. Postoperatively, duplex scanning had a sensitivity of 79%, a specificity of 98%, and an accuracy of 97% when venography was considered as the gold standard. The postoperative incidence of proximal DVT was 12% in this group of THA patients treated with mechanical and pharmacologic prophylaxis. Including calf vein thrombosis, 30% had DVT postoperatively. This study demonstrates the efficacy of duplex scanning for diagnosing proximal DVT and describes an effective noninvasive method of screening THA patients for the presence of proximal DVT.

False Negative Reactions↗
PubMed1991

Preoperative venography. A risk factor for postoperative deep venous thrombosis in hip arthroplasty patients?

The incidence of postoperative deep venous thrombosis was compared between patients who had or had not received a preoperative screening venogram. No statistically significant difference in the deep venous thrombosis rate was noted postoperatively. Thirty percent of patients who received a preoperative venogram developed postoperative deep venous thrombosis, and 28% of those who did not have a preoperative venogram developed postoperative deep venous thrombosis. These results suggest that an orthopaedic surgeon may order a preoperative venogram for a patient at potential high risk of thromboembolic complications without predisposing the patient to an increased risk of postoperative deep venous thrombosis.

Causality↗
PubMed1991

Porous-coated anatomic total knee arthroplasty. A prospective analysis comparing cemented and cementless fixation.

The results of 26 cementless porous-coated anatomic (PCA) total knee arthroplasties (TKAs) were analyzed and compared to 25 cemented PCA TKAs. Identical prospective protocols were followed. The mean preoperative and postoperative knee scores at an average three-year follow-up interval (range, two to five years) were 59.6 and 81.5 for cementless knees compared to 57.6 and 80.4 for cemented knees. The difference was not statistically significant (p greater than 0.10). Blood loss was significantly higher in the cementless knees (p = 0.02). Radiolucent lines, loose beads, and tibial component subsidence were more frequent in cementless knees. No differences between cementless and cemented knees were observed in the femoral components. The PCA femoral components implanted without cement compare favorably to those implanted with cement. The PCA tibial and patellar components are more reliably secured with cement.

Adult↗
PubMed1990

The use of two nutritional indicators in identifying long bone fracture patients who do and do not develop infections.

One hundred consecutive orthopedic long bone fracture patients requiring surgical fixation were nutritionally assessed using both the nutritional index of Rainey-MacDonald et al. and total lymphocyte count. The ability of these two parameters to identify correctly those patients who do and do not develop postoperative complications was assessed using several error rate measures, which included sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Fourteen of our patients developed postoperative complications. All complications observed were infections. The accuracy of the nutritional index and total lymphocyte count in predicting patient outcome was 78 and 51%, respectively. The positive and negative predictive values calculated for the nutritional index were 36 and 94%, respectively. Total lymphocyte count analysis resulted in positive and negative predictive values of 15 and 87%, respectively. In our sample of patients, the nutritional index was a better predictor of patient outcome than total lymphocyte count, as indicated by the higher accuracy rate calculated for the nutritional index. Based upon positive predictive value results, neither of these indicators was most accurate in identifying patients who did develop infections. Not unexpectedly, both indicators were best in identifying those patients who did not develop postoperative infections.

Adolescent↗
PubMed1990

Fine-needle aspiration biopsy: an analysis of 89 head and neck cases.

In a recent 2-year period, 89 fine-needle aspiration biopsies (FNAB) were performed on head and neck lesions in 81 patients from 6 to 97 years of age. Eighty-four of the FNABs were considered diagnostic. Thirty of the aspirates were diagnosed as benign whereas 54 were diagnosed as malignant. Three specimens were suspicious for malignancy, and 2 specimens were considered nondiagnostic. The most common malignant diagnosis was squamous cell carcinoma, which involved 32 of the specimens. The most common benign diagnosis was pleomorphic adenoma. Subsequent surgical biopsy specimens were available in 45 of the patients. Of these, 41 were consistent with the FNAB diagnosis, whereas 4 were not.

Adenocarcinoma↗
PubMed1990

An evaluation of calvarial and iliac donor sites in alveolar cleft grafting.

A clinical study evaluating the use of calvarial (two different techniques of harvest) versus iliac donor bone in secondary unilateral alveolar cleft reconstruction based on clinical and radiographic assessment was conducted. Both iliac bone and the Hudson brace harvested calvarial bone resulted in high rates of radiographic evidence of osseous continuity between the maxillary segments and clinical resolution of the alveolar cleft defect. Calvarial bone obtained with the craniotome had a lower rate of success that was statistically different from the other two groups. The utilization of calvarial bone and the implications of harvest technique on graft transfer biology are discussed.

Alveolar Process↗
PubMed1990

Universal total hip replacement with focus on the acetabular component and the hybrid hip.

One hundred sixty-one porous-coated Universal (Biomet Inc, Warsaw, IN) total hip arthroplasties were performed and studied preoperatively between July 1986 and June 1989. The study included 59 men (38 at 1-year follow-up; 21 at 2-year follow-up) and 91 women (60 at 1-year follow-up; 31 at 2-year follow-up). The average age was 62 years at 12-month follow-up and 64.7 years at 24-month follow-up (range 28 to 90 years). Three groups of patients with components were evaluated both clinically and radiographically: uncemented femoral and acetabular components (group 1); cemented femoral stems and uncemented acetabular components, ie, hybrid total hip arthroplasties (group 2); and revision total hip replacement arthroplasties (group 3). Clinical results for all groups showed Harris hip scores of 87 at 1-year follow-up and 89 at 2-year follow-up. Moderate to no limp occurred in 93% of patients at 1-year follow-up and 95% at 2-year follow-up. No ambulatory aids were used by 43% of patients at 1-year follow-up or 47% at 2-year follow-up. Both walking distance and endurance improved over time. Anthropometric analysis showed no progressive lucencies around the femoral or acetabular component in either group. A Kaplan-Meier survivorship analysis could not be used, because there was only one failure. This eliminated a comparison group for those lost to follow-up. Early clinical and radiographic results have been encouraging; however, long-term analysis is needed to accurately assess the success of this total hip arthroplasty system.

Acetabulum↗
PubMed1990

The preoperative prevalence and postoperative incidence of thromboembolism in patients with hip fractures treated with dextran prophylaxis.

A prospective preoperative and postoperative venographic study of hip fracture patients has documented a significant preoperative prevalence and postoperative incidence of thromboembolic disease. A statistically higher incidence of deep-venous thrombosis is observed in patients with femoral neck fractures compared to patients with intertrochanteric fractures. A 9% (15 of 176) preoperative prevalence and an 11% (12 of 108) incidence of new postoperative thromboembolic disease were detected. There was a predilection for deep-venous thrombosis in the injured extremity compared to the noninjured extremity both preoperatively and postoperatively.

Adult↗
PubMed1990

Blood conservation techniques in orthopaedic surgery.

In summary, reduction of blood loss and coincidental decrease in the number of blood transfusions is now of paramount importance in orthopaedic surgery. Methods to reduce blood loss include preoperative planning, hypotensive anesthesia, and meticulous surgical technique. If transfusion is necessary, autologous replacement is always preferable. Overall, the goals in blood conservation in surgery are first to decrease the amount of blood lost, and second to be sensible in replacement of this loss.

Blood Transfusion↗
PubMed1990

Blood products: optimal use, conservation, and safety.

A review of our experience in total joint arthroplasty revealed that the cell saver was not cost-effective in the case of routine primary hip or knee replacement. Its use should be restricted to cases of revision hip and knee surgery in which infection has been ruled out. Preoperative aspiration remains the most reliable method for accomplishing this. However, if the aspiration is negative and the intra-articular fluid obtained at the time of surgery is suspicious for infection, either in appearance or on Gram stain or cell count, it is best to abandon use of the cell saver. Predonation should be routine for all hip replacement cases unless there are specific contraindications. In general, there is good acceptance of this program by patients, although a few have specifically indicated they would prefer to run the risk of homologous transfusion. Two units available for primary replacement are more than ample. In cases of revisions, a first revision justifies a minimum of 3 units. For complex revision cases involving patients with three or more previous procedures on the hip, or those requiring significant bone resection or large segment grafting, the maximum possible number of units should be obtained. Autologous blood reinfusion should be done for essentially the same indications as homologous transfusion even though risks are sharply reduced. The local source for autologous collection will then follow its own specific protocol for the disposition of remaining units. In every case, the surgical technique should be careful and directed toward limiting intraoperative blood loss.

Blood Transfusion, Autologous↗