Biomedical subjects

David Zurakowski

Publications and source records attributed to David Zurakowski.

173 records · Page 10Linked to original sources

PubMedDate not supplied

Total shoulder arthroplasty: long-term survivorship, functional outcome, and quality of life.

This study examines long-term outcomes of total shoulder arthroplasty (TSA) via survivorship analysis, patient questionnaires, and minimum 10-year physical examinations. The study group consisted of 320 consecutive TSAs performed in 267 patients between 1974 and 1988. Diagnoses included rheumatoid arthritis (69%), osteoarthritis (22%), and juvenile rheumatoid arthritis (4.7%). Minimum 10-year physical examination follow-up was obtained on a subset of 72 TSAs at a mean (+/- SD) of 14.0 +/- 2.7 years. A Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was obtained from 80 patients with 103 TSAs at a mean of 15.4 +/- 3.4 years after the index procedure (range, 10.4-23.2 years). Kaplan-Meier survivorship rates with revision as the endpoint at 5, 10, 15, and 20 years were 98%, 93%, 88%, and 85%, respectively. Of the shoulders, 22 (6.9%) required a revision, most commonly for loosening of one or both components (15 shoulders). Dislocation occurred earlier than other causes of revision or complication (P < .05, analysis of variance). Minimum 10-year physical examination follow-up revealed lasting, significant improvements in range of motion and strength. The patients' subjective assessments of TSA were favorable in that 92% felt that their shoulder was "much better" or "better" after TSA. The mean DASH score was 49 +/- 25; no significant differences were found among diagnoses. Long-term analysis of the Neer-type TSA revealed survivorship rates comparable to other joint replacements. The significant improvements in relief of pain, shoulder range of motion, and strength are associated with a high degree of patient satisfaction.

Adolescent↗

PubMedDate not supplied

Efficacy of lidocaine or bupivacaine combined with ephedrine in rat sciatic nerve block.

BACKGROUND AND OBJECTIVES: The adrenergic drug ephedrine inhibits Na(+) current in cultured cells expressing Na(+) channels and provides dose-dependent reversible rat sciatic nerve blockade. The dosage required for peripheral nerve blockade in humans would cause unacceptable cardiovascular side effects. We therefore hypothesized that either lidocaine or bupivacaine would show synergy with ephedrine in a rat sciatic nerve block model, allowing a dose reduction and limiting side effects while improving efficacy. METHODS: Sciatic nerves of anesthetized rats were exposed by lateral incision of the thighs; 0.2 mL of different concentrations of the following drugs was injected sub-fascially: bupivacaine, lidocaine, and ephedrine alone and bupivacaine or lidocaine combined with ephedrine (n=8 per group). After animals recovered from anesthesia, a blinded investigator evaluated motor blockade (push against a balance) and sensory/nociceptive blockade (to pinch of the fifth toe) at predefined time intervals. RESULTS: Ephedrine combined with bupivacaine interacted additively for both motor and sensory blockade, and ephedrine combined with lidocaine interacted antagonistically (sub-additive) for sensory blockade and additively for motor blockade. CONCLUSIONS: A combination of ephedrine with either lidocaine or bupivacaine is unlikely to allow a significant dose reduction because of a lack of synergy. Furthermore, the cardiovascular side effects will limit the maximal tolerable dosage of ephedrine.

Adrenergic Agents↗

PubMedDate not supplied

Glaucoma drainage devices: a systematic literature review and current controversies.

Glaucoma drainage devices create alternate aqueous pathways by channeling aqueous from the anterior chamber through a long tube to an equatorial plate that promotes bleb formation. Glaucoma drainage devices are being used more frequently in the treatment of glaucoma that does not respond to medications or trabeculectomy operations. In certain conditions, such as neovascular glaucoma, iridio-corneal syndrome, penetrating keratoplasty with glaucoma, glaucoma following retinal detachment surgery, and so on, it is becoming the primary operation. This review provides a systematic review of the literature and outlines the current controversies involving different glaucoma drainage devices and their design, overall surgical success, and complications following glaucoma drainage device insertion.

Clinical Trials as Topic↗

PubMedDate not supplied

Accuracy of a new low-flow sidestream capnography technology in newborns: a pilot study.

OBJECTIVE: To evaluate the accuracy of a new low-flow sidestream capnography technology and analyze components of the capnogram in mechanically ventilated newborns with and without pulmonary disease. METHODS: Twenty patients were prospectively identified. Eligible infants were mechanically ventilated and had an indwelling arterial catheter. Two groups were identified: newborns who were receiving mechanical ventilation for pulmonary diseases, and newborns who were receiving postoperative mechanical ventilation for nonpulmonary conditions. End-tidal CO(2) (PetCO(2)) was measured for 1-minute pre- and post-arterial blood sampling, and PetCO(2) and PaCO(2) were compared for each patient. Eight quantitative waveform parameters were also measured on all patients. RESULTS: Newborns in the pulmonary group (n=13) (persistent pulmonary hypertension of the newborn/meconium aspiration syndrome, respiratory distress syndrome, pneumonia) and newborns in the control group (n=7) were matched for birth weight, gestational age, and postnatal age. PetCO(2)-PaCO2 Gradient values were higher in the pulmonary group (7.4+/-3.3 mm Hg) than controls (3.4+/-2.4 mm Hg). Four waveform parameters (ascending slope, alveolar angle, alpha angle, descending angle) were identified, which independently differentiated patients with pulmonary disease from controls. CONCLUSIONS: Low-flow capnography with Microstream technology accurately measured alveolar CO(2) in newborns without pulmonary disease, as demonstrated by normal PetCO(2)-PaCO(2) gradients. The measured PetCO(2)-PaCO(2) gradient, as expected, was significantly higher in newborns with pulmonary disease. We also identified four quantitative waveform parameters that may be useful in differentiating between mechanically ventilated newborn patients with and without lung disease.

Capnography↗

PubMedDate not supplied

A non-heart-beating donor model to evaluate functional and morphologic outcomes in resuscitated pig hearts.

A non-heart-beating donor model was considered to examine whether pig hearts from the abattoir could be resuscitated by whole blood reperfusion. For preservation, machine perfusion using University of Wisconsin (UW) solution was compared with storage on ice. Nineteen hearts from abattoir pigs, harvested 25 +/- 3 min after exsanguination, were harvested and transported to the laboratory. Controls (n = 7) were immediately reperfused with homologous whole pig blood in an isolated heart model for 60 min with monitoring of left ventricular developed pressure (LVDP), contractility, and coronary flow. UW solution hearts (UW, n = 6) were perfused for 4 h with 10 degrees C cold UW solution before blood reperfusion. In the cold storage group (CS, n = 6), the organs were stored for an additional 4 h on ice before blood reperfusion. In all hearts, histology was performed after 60 min of blood reperfusion to evaluate myocardial reperfusion injury. All three groups showed significant increases in LVDP (p <.001), although this functional recovery was earliest in the control group and latest in the UW group. Significant declines were observed for both LVDP and contractility from the peak values in each group to the end of blood reperfusion. Coronary flow increased steadily over the time course for the UW group, whereas in the control and CS groups flow increased during the first 15 min of blood reperfusion and then decreased. In the UW and CS groups, there were significant positive correlations between coronary flow and LVDP (p <.001). Microscopic examination revealed no differences between the three groups. Thus, hearts from an abattoir with 25 min of warm ischemic time can be resuscitated. For storage of these organs, continuous machine perfusion with UW solution is superior to cold storage on ice.

Adenosine↗

PubMedDate not supplied

Complications and timing of follow-up after closed reduction and percutaneous pinning of supracondylar humerus fractures: follow-up after percutaneous pinning of supracondylar humerus fractures.

The purpose of this study was to evaluate the need for clinical evaluation with radiographs within 10 days of closed reduction and percutaneous pinning for the treatment of displaced supracondylar humerus fractures. Between May 1 and December 31, 2001, the authors evaluated the complications with closed reduction and percutaneous pinning of 104 displaced supracondylar humerus fractures. Fifty-two of the patients had the initial follow-up examination with radiographs 10 days or less after pinning; the other 52 patients had the initial follow-up examination with radiographs either after 10 days or on the day of pin removal. The overall complication rate for the series was 7.7% (8/104). All eight complications were in type III fractures. The early follow-up group had six complications; the late follow-up group had two complications. Baumann's angle, lateral humerocapitellar angle, and lateral rotational percentage were not significantly different between the two groups. The only variable tested that was associated with a complication was pin configuration. No association between late follow-up and complications was identified. The authors conclude that clinical and radiographic evaluation of routine displaced supracondylar humerus fractures requiring closed reduction and percutaneous pinning may be safely delayed until pin removal.

Bone Nails↗

PubMedDate not supplied

Use and satisfaction of the internet in obtaining information on brachial plexus birth palsies and its influence on decision-making.

The purpose of this study was to determine the influence of the Internet on parents regarding decisions for children with brachial plexus birth palsies (BPBP). A power analysis was performed to determine the appropriate sample size needed for estimating proportions in the general BPBP population. At least 100 surveys were needed for appropriate data analysis and 122 surveys were collected (100% response rate). Each participant filled out a 32-item survey on demographics, questions on Internet usage, and the influence of the Internet on care decisions. It is evident that parents commonly access the Internet. Of 122 participants, 108 (89%) searched the Internet for general BPBP information. Topics commonly researched include causes (76%), symptoms (70%), treatment/surgical options (84%), choice of physicians/surgeons (60%), and choice of hospitals/clinics (60%). Our study reveals that over half of the Internet users make clinical decisions based on their research and 98% report satisfaction with the outcome of their decisions. It is clear that parents of children with BPBP frequently use the Internet for information and available options regarding care for this rare condition.

Adult↗

PubMedDate not supplied

A comparison of methods for measuring spinal motion in female patients with adolescent idiopathic scoliosis.

Noninvasive surface measures of spine motion are validated in adult patients but are infrequently used in adolescent scoliosis patients. The agreement between surface and radiographic measurements of spinal motion is not known. We performed a comparative prospective analysis of 3 methods to measure spinal motion in female patients with adolescent idiopathic scoliosis (AIS) to establish normative data of spinal motion in AIS patients and evaluate the relationship between surface and radiographic measurements of spine motion. Measurements were obtained using a cloth tape measure, dual inclinometers, and a 3-dimensional electrogoniometer in 37 female patients with AIS. Radiographic parameters of the deformity were correlated with the spine motion. Differences between methods were evaluated by paired t tests. The Bland-Altman method was applied to evaluate agreement in measuring flexion. The average spinal flexion was 5.7 +/- 2.2 cm by the modified Schober method, 49 +/- 11 degrees by the dual inclinometers method, and 64 +/- 10 degrees by the 3-dimensional electrogoniometer. Spinal motion did not vary with magnitude of the scoliosis. In addition, surface measurements of spinal motion did not correlate with radiographic measurements of scoliosis flexibility. In this study, the amount of spinal motion varied, depending on the method of measurement. Surface measurements of motion cannot predict the magnitude or flexibility of the scoliosis.

Adolescent↗

PubMedDate not supplied

Partial tears of the anterior cruciate ligament in children and adolescents.

BACKGROUND: The functional outcome after partial anterior cruciate ligament tears in children and adolescents treated without reconstruction has not been established. HYPOTHESIS: Nonreconstructive management of partial anterior cruciate ligament tears can be effective in certain pediatric patients. STUDY DESIGN: Prospective cohort study. METHODS: We studied 45 skeletally mature and immature patients 17 years of age or less who had an acute hemarthrosis, magnetic resonance imaging signal changes, grade A or B Lachman and pivot shift result, and an arthroscopically documented partial anterior cruciate ligament tears. All patients were treated without reconstruction, underwent a structured rehabilitation program, and were followed up for a minimum of 2 years. RESULTS: Fourteen patients (31%) underwent subsequent reconstruction. Significant associations with subsequent reconstruction included tears that were greater than 50%, predominantly posterolateral tears, a grade B pivot shift test result, and older chronologic and skeletal age. Among patients who did not require reconstruction, those with tears that were greater than 50% or predominantly posterolateral had significantly lower Lysholm, satisfaction, and Cincinnati Knee Scale scores. CONCLUSIONS: Nonreconstructive management is recommended for partial anterior cruciate ligament tears in children and adolescents 14 years of skeletal age or younger with normal or near-normal Lachman and pivot shift results. Reconstruction is recommended in older athletes or in those with greater than 50% or predominantly posterolateral tears.

Adolescent↗

PubMedDate not supplied

Comparison of double-plate Molteno and Ahmed glaucoma valve in patients with advanced uncontrolled glaucoma.

BACKGROUND AND OBJECTIVE: To compare double-plate Molteno (DPM) with the Ahmed glaucoma valve (AGV) in the treatment of eyes with complicated glaucoma. PATIENTS AND METHODS: This matched, retrospective, case-control study was based on diagnosis, number of previous operations, and age. There were 30 patients in each group and only patients with a minimum of 6 months follow up were included. Double-plate Molteno or Ahmed glaucoma valve insertion was performed on each patient to control intractable glaucoma. Success was defined as IOP <22 mm Hg and >4 mm Hg on the last two visits, a decrease of no more than 2 lines in the visual acuity, and no additional surgical intervention to control IOP. RESULTS: The Kaplan-Meier estimated probability of success at 12 and 24 months was 73% and 56% with DPM and 60% and 50% for AGV (P = 0.72). Mean IOP measured 13.36 +/- 5.2 mm Hg following DPM and 16.7 +/- 5.6 mm Hg following AGV at 12 months (P = 0.026) and 13.3 +/- 5.1 mm Hg with DPM and 19 +/- 5.8 mm Hg with AGV at 24 months (P = 0.009). Of the patients involved in the study, 83.5% exhibited hypertensive phase (HP) of AGV vs 43.5% of DPM (P = 0.04). AGV had a tendency to fail earlier (5 months +/- 7 following AGV vs 13 months +/- 13 following DPM, P = 0.07, t-test). Patients with either a second valve insertion or valve removal were 7/30 of AGV vs 1/30 in DPM (P = 0.05). Stent removal was needed by 10/30 DPM and 8/30 AGV had needling/5-FU. CONCLUSIONS: The percentage of patients free from failure was similar between the two groups at 36 months. DPM is associated with lower mean IOP in the long term compared to AGV.

Adolescent↗

PubMedDate not supplied

CD44s expression is associated with improved survival in soft tissue sarcoma.

Expression of CD44 has been identified as a prognostic factor in several malignant diseases. Few studies have correlated CD44 expression in soft tissue sarcoma with subsequent tumor progression or recurrence. We sought to investigate the clinical significance of CD44s (standard) in adult soft tissue sarcoma (STS). Tumor specimens of 62 patients with STS were evaluated by immunohistochemistry for CD44s expression. The primary outcome measures were survival and local recurrence. Of 62 analyzed specimens, 49 tumors were CD44s-positive compared to 13 CD44s-negative tumors. Kaplan-Meier survival analysis indicated significantly better survival among patients whose tumor was CD44s-positive (p=0.015). CD44s expression (hazard ratio, 3.1; 95% confidence interval, 1.5 to 7.0), tumor size (hazard ratio, 11.7; 95% confidence interval, 1.8 to 322) and resection quality (R1 vs. R0: hazard ratio, 8.7; 95% confidence interval, 3.1 to 24.5) were independent predictors of survival in multivariate analysis. CD44s expression correlates with prognosis of soft tissue sarcomas and therefore may have a pathogenetic role in tumor progression. Our results suggest that expression of CD44s in primary STS provides value regarding the progression of STS and, therefore, could be useful in selecting patients for adjuvant treatment.

Adult↗