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Biomedical subjects

C G Moran

Publications and source records attributed to C G Moran.

At least 37 records · Page 2Linked to original sources
PubMed1996

Injuries related to car crime: the joy-riding epidemic.

'Joy-riding' is the term used, somewhat inappropriately, for the offence of taking a vehicle without the owner's consent. In certain areas, mainly deprived inner-city estates, there has been an increase in this crime. The aim of this study was to investigate its impact on the workload of an inner-city teaching hospital's busy accident and orthopaedic departments. In this prospective study, all patients admitted to hospital as a result of road-traffic accidents (RTAs) were identified during a 9 month period. A total of 1576 patients were admitted to the trauma unit. One hundred and fifty-two admissions were as a result of RTA and 20 (13 per cent) of these patients had injuries as a result of car crime. Of this group, eight were severely injured (ISS > 16) and six of these were innocent bystanders. Three patients (one joy-rider and two innocent bystanders) died as a result of car crime. The average length of hospital stay was 12 days (1-62 days) and the hospital in-patient costs were estimated to be at least 5200 pounds per patient. Injuries related to car crime results in a significant amount of work and financial cost to the National Health Service.

Accidents, Traffic↗
PubMed1996

Kinematic condylar total knee arthroplasty. 14-year survivorship analysis of 208 consecutive cases.

We performed an independent survivorship analysis on 208 Kinematic Condylar knee replacements with a minimum follow-up of ten years and a mean of 12 years. Seven patients had been lost to follow-up. At ten years the estimated survival was 92% (95% confidence limits 95% and 87%) and when stratified for diagnosis and thickness of polyethylene there was no statistical difference (p > 0.05) in survivorship of knees with osteoarthritis or rheumatoid arthritis. We conclude that the original design of the Kinematic Condylar knee replacement has a good record and that adequate evaluation of new designs of implant should be undertaken before they are widely introduced.

Adult↗
PubMed1996

Survivorship analysis of the Kinematic Stabilizer total knee replacement: a 10- to 14-year follow-up.

The Kinematic Stabilizer is a posterior-cruciate-substituting design of total knee replacement. We have reviewed 109 primary total knee replacements in 95 patients at a mean follow-up time of 12.7 years (10 to 14). We used survival analysis with failure defined as revision of the implant. This gave a cumulative survival rate of 95% (95% CI +/- 5%) at ten years and (87% +/- 10%) at 13 years. These results from an independent centre confirm the value of an established design of cemented total knee replacement and question the wisdom of the introduction of modifications and new designs without properly controlled trials.

Adult↗
PubMed1996

Systemic release of cobalt and chromium after uncemented total hip replacement.

We measured the levels of cobalt and chromium in the serum in three groups of patients after uncemented porous-coated arthroplasty. Group 1 consisted of 14 consecutive patients undergoing revision for aseptic loosening. Group 2 comprised 14 matched patients in whom the arthroplasty was stable and group 3 was 14 similarly matched patients with arthritis awaiting hip replacement. Specimens were analysed using atomic absorption spectrophotometry. Aseptic loosening of a component resulted in a significant elevation of serum cobalt (p < 0.05), but not of serum chromium. The relative risk of a component being loose, if the patient had a serum cobalt greater than 9.0 nmol/l, was 2.8.

Adult↗
PubMed1995

Reperfusion injury in vascularized bone allografts.

A vascularized allograft canine tibia was used to evaluate the preservation of the osseous microcirculation. Six pairs of adult tibiae were harvested, and a vascular washout was performed with mannitol solution. The bones then were perfused continuously (0.03 ml/min at 5 degrees C) for 20 hours with University of Wisconsin solution. Following storage, each pair of bones was transplanted, by microvascular anastomosis, to a recipient dog, and bone blood flow was estimated using the radiolabeled microsphere method. Adrenoreceptor control mechanisms were evaluated in one specimen, and endothelial function was evaluated in the contralateral specimen. Alpha 1-adrenoreceptor blockade produced a significant increase (89 +/- 80%) in bone blood flow (p < 0.05). A further increase (99 +/- 56%) was observed with the addition of alpha 2-blockade (p < 0.01). Acetylcholine produced a decrease (65 +/- 65%) in blood flow (p < 0.01). This effect was inhibited by L-NG-monomethyl-arginine, which resulted in an increase (53 +/- 47%) in bone blood flow (p < 0.05). The no-reflow phenomenon was observed in two vascularized allografts. These results demonstrate that smooth muscle adrenoreceptors were preserved successfully for 24 hours. In contrast, endothelial function was abnormal. There was no evidence that the endothelium was producing endothelium-derived relaxing factor, and the results suggest that an endothelium-derived constricting factor dependent on L-arginine was produced during reperfusion. It is concluded that University of Wisconsin solution does not preserve normal endothelial function in the microcirculation of bone.

Anastomosis, Surgical↗
PubMed1995

134 tibial shaft fractures managed with the Dynamic Axial Fixator.

We have reviewed the results of 134 tibial shaft fractures treated with the Dynamic Axial Fixator. In 86 closed fractures, the average union time was 4 months. 76 fractures had united by 5 months; delayed union occurred in 7 cases. 3 closed fractures failed to unite. In 48 open fractures, the union time was related to the severity of soft tissue trauma. The average union time was 5 months for grade II and 6 months for grade III open fractures. 33 open fractures had united by 5 months and delayed union occurred in 11 fractures. 4 open fractures failed to unite. The commonest complication was minor pin site infection, which was seen in 34 percent. These responded rapidly to treatment and external fixation continued. Major pin site infections were uncommon (5 percent) and none led to any serious sequelae. We have found the Dynamic Axial Fixator a safe and reliable device for treating fractures of the tibial shaft.

Adolescent↗
PubMed1994

Hepatitis B immunization: a survey of orthopaedic surgeons.

In 1988 a survey of 72 orthopaedic surgeons was performed to determine the rate of immunization against the hepatitis B virus (HBV). 54% had received the vaccine. Offers of immunization from occupational health departments doubled the rate of uptake. Only 51% of surgeons had been offered this service. A repeat survey was performed in 1992 to assess the effect of recent publicity on viral transmission during surgery. 81% have now received the vaccine.

Hepatitis B↗
PubMed1994

Results of uncemented porous-coated anatomic total hip replacement.

We reviewed a consecutive series of 241 uncemented, porous-coated anatomic (PCA) hip replacements at an average follow-up of five years (2 to 9). Of these, 32 had failed (13%), 26 at the acetabular component (11%) and six at the femoral component (2%). Acetabular failure was associated with local osteolysis and excessive polyethylene wear in 20 cases: in these histological examination showed giant macrophages incorporating numerous particles of high-density polyethylene. The femoral failures were related to a poor intramedullary fit with subsequent subsidence. Using the recommendation for revision as the end point, the cumulative survival rate for prostheses was 91% at six years (95% CI +/- 6%), 73% (+/- 11%) at seven years, and 57% (+/- 20%) at eight years. The result of uncemented PCA hip replacement is satisfactory up to six years, but then increasing failure of the acetabular component appears to be due to polyethylene wear, leading to osteolysis, loosening and component migration. At first, failure is often asymptomatic; routine follow-up of uncemented hip replacement is essential, especially after five years.

Acetabulum↗
PubMed1994

Canine bone blood flow measurements using serial microsphere injections.

The objective of this study was to determine the reproducibility of serial bone blood flow (BBF) quantitation using multiple microsphere injections. Three consecutive estimates of BBF were obtained, using 15-mu radionuclide-labeled microspheres from 21 anesthetized adult dogs. A dose of 3 million spheres/kg was used in seven dogs (Cohort 1); a dose of 0.5 million spheres/kg was used in the remaining 14 dogs (Cohorts 2 and 3). Estimates of BBF were made at an average of 129, 153, and 175 minutes after the animals had been anesthetized in the first two cohorts and 179, 203, and 225 minutes in Cohort 3. The dogs in Cohort 1 had no surgical intervention; the dogs in Cohorts 2 and 3 had increasingly complex surgical interventions. Despite stabilization of cardiovascular status, BBF was found to vary by 33.4% in Cohort 1, 25.7% in Cohort 2, and 42.5% in Cohort 3 over the three injections. Cortical BBF fell by 13.9%, 12.1%, and 12.4% between the first and second, and by 31.0%, 11.2%, and 29.9% between the second and third estimates for Cohorts 1, 2, and 3, respectively. Variation in right to left blood flow was used as an overall measure of error caused by technique and did not consistently increase between the first, second, or third BBF estimates in any cohort. Cortical BBF data were found to be significantly more reliable than cancellous data (p < 0.01); error caused by technique was least in the midshaft femoral or midshaft humeral cortical samples. Increasing the dose of spheres administered from 0.5 to 3 million/kg for three serial microsphere injections increased the number of reliable samples and did not lead to increased technical error or shunting. This study demonstrates that there is a significant decrease in BBF over time in the anesthetized dog; therefore, serial estimates of BBF can only be interpreted if the results are normalized or if a control group of animals is included.

Animals↗
PubMed1993

Adrenergic control mechanisms of blood flow in a vascularized canine tibial allograft.

A vascularized canine tibial allograft was used to study the alpha-adrenoreceptor subtypes of the microcirculation of bone. Bone transplantation was performed on six dogs, and the bone blood flow was estimated with the use of serial injections of radiolabeled 15 microns microspheres. After microvascular anastomosis, the mean cortical blood flow in the allografted tibia was 3.6 +/- 2.1 ml/100 g/min. Alpha 1-adrenoreceptor blockade, with prazosin, caused an increase in normalized blood flow in five allografts and a slight decrease in one allograft. The mean increase was 32 +/- 48%, but this was not statistically significant (p < 0.2). The addition of an alpha 2-adrenoreceptor blockade, with rauwolszin, resulted in a significant increase (132 +/- 88%) in normalized blood flow in all allografts (p < 0.02). This ex vivo experiment confirms that both alpha 1 and alpha 2 adrenergic mechanisms play a role in controlling bone blood flow in centrally denervated allografts.

Animals↗
PubMed1993

Preservation of bone graft vascularity with the University of Wisconsin cold storage solution.

The preservation of the microcirculation of bone has been evaluated with use of an in vitro canine tibia perfusion model. The production of relaxing factors by the osseous vascular endothelium was used as a metabolic marker for viability. This endothelial eccrine function was preserved for 5 days (120 h) by cold storage without continuous perfusion after a washout with the University of Wisconsin (UW) solution. This synthetic perfusate was superior to Krebs Ringer solution (p < 0.05), but storage without perfusion failed to prevent a significant rise in vascular resistance. Two techniques were effective for the preservation of bone vascularity for 24 h: washout with UW solution followed by nonperfusion cold (4 degrees C) storage, and vascular washout with mannitol solution followed by continuous hypothermic (5 degrees C) microperfusion (0.03 ml/min) with UW solution. The most consistent, and lowest, vascular resistance was produced by the microperfusion technique. However, UW solution does not consistently prevent an increase in vascular resistance with hypothermic ischemia. This technique may prove useful for the preservation of vascularized bone grafts, but it needs to be evaluated in a transplantation model.

Adenosine↗
PubMed1993

Glove perforation during hip arthroplasty. A randomised prospective study of a new taperpoint needle.

Exposure to blood is a hazard for all surgeons. We assessed the incidence of glove perforation and needlestick injury from a new blunt taperpoint needle designed to penetrate tissues other than skin with the minimum of force. We performed a prospective, randomised trial comparing the incidence of perforations of surgical gloves with the new needle and a standard cutting needle during wound closure after hip arthroplasties. There was at least one glove perforation in 46 of 69 such procedures (67%). The use of the taperpoint needle produced a significant decrease in perforations (p = 0.049).

Aged↗
PubMed1993

The incidence of fatal pulmonary embolism after knee replacement with no prophylactic anticoagulation.

We made a prospective study of the incidence of fatal pulmonary embolism in patients after total knee replacement with no prophylactic anticoagulation. There were 499 consecutive patients having 527 knee replacements. They all wore anti-thromboembolic stockings and were mobilised 48 hours after surgery. No patient was lost to follow-up. One patient died of pulmonary embolism 22 days after operation. There were no other deaths within three months of operation. The incidence of fatal pulmonary embolism was 0.19% (95% confidence interval: 0 to 0.6%). Fatal pulmonary embolism is rare after total knee replacement without prophylactic anticoagulation and the routine anticoagulation of these patients is of doubtful value.

Adolescent↗
PubMed1993

Vascularized bone autografts.

Recent advances in microvascular surgery have made it possible to reconstruct large skeletal defects with autogenous bone grafts on a vascular pedicle. Experimental studies have demonstrated that vascularized bone grafts have superior blood flow and osteocyte survival when compared with nonvascular grafts. This improves the union rate and allows full incorporation of cortical bone, remodeling, and graft hypertrophy. Clinical experience over the past decade demonstrates that 80% to 90% of these grafts are ultimately successful, allowing limb salvage in complex reconstructive cases. However, the technique is technically demanding, has a relatively high complication rate, and requires prolonged immobilization and rehabilitation. Thus, vascularized bone grafts should only be used when simpler reconstructive techniques are unlikely to succeed.

Bone Transplantation↗
PubMed1992

Failure of perfusion with oxygenated Krebs-Ringer solution to preserve the eccrine function of the vascular endothelium in bone.

An ex vivo canine tibia preparation was perfused at a constant rate with aerated (95% O2-5% CO2) Krebs-Ringer solution for 24 h. Bolus injections of norepinephrine (0.125-0.5 micrograms) were given and then acetylcholine (5 x 10(-5) M) was used to stimulate endothelial production of smooth muscle relaxing factors. Following 1 h of perfusion the addition of acetylcholine resulted in significant attenuation of the response to norepinephrine (p < 0.001). After 4 h perfusion acetylcholine did not attenuate the norepinephrine response, but addition of L-arginine (the precursor of endothelial-derived relaxing factor) resulted in significant attenuation in the presence of acetylcholine (p < 0.005). At 6, 12, and 24 h the acetylcholine did not attenuate the norepinephrine response. It is concluded that normothermic, continuous perfusion with oxygenated Krebs-Ringer solution results in normal endothelial eccrine activity up to 1 h. Following this period there is substrate depletion but endothelial eccrine function can be demonstrated for up to 4 h. At 6 h this function cannot be demonstrated, suggesting degradation of the functional integrity of the endothelium.

Acetylcholine↗