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Biomedical subjects

L Kull

Publications and source records attributed to L Kull.

7 recordsLinked to original sources

The effect of propofol on intraoperative electrocorticography and cortical stimulation during awake craniotomies in children.

Propofol has been proposed as a sedative agent during awake craniotomies. However, there are reports of propofol suppressing spontaneous epileptiform electrocorticography (ECoG) activity during seizure surgery, while others describe propofol-induced epileptiform activity. The purpose of this study was to determine if propofol interferes with ECoG and direct cortical stimulation during awake craniotomies in children. Children scheduled for awake craniotomies for resection of epileptic foci or tumours were studied. An intravenous bolus of 1-2 mg.kg-1 followed by infusion of 100-200 microgram.kg-1.min-1 of propofol was administered to induce unconsciousness. Fentanyl (0.5 microgram.kg-1) was administered incrementally to provide analgesia. After the cortex was exposed, the propofol infusion was stopped and the patient permitted to awaken. Cortical electrodes were applied. ECoG was recorded continuously on a Grass polygraph. Motor, sensory, language, and memory testing were done throughout the procedure. The cortex was stimulated with a hand-held electrode using sequential increases in voltage to map the relevant speech and motor areas. We studied 12 children (aged 11-15 years) with intractable seizures. The raw ECoG did not reveal any prolonged beta-waves associated with propofol effect. Electroencephalogram spikes due to spontaneous activity or cortical stimulation were easily detected. Cognitive, memory and speech testing was also successful. We conclude that propofol did not interfere with intraoperative ECoG during awake craniotomies. Using this technique, we were able to fully assess motor, sensory, cognitive, speech and memory function and simultaneously avoid routine airway manipulation.

Adolescent↗

The fate of well fixed cemented femoral components left in place at the time of revision of the acetabular component.

The results were reviewed for thirty-seven hips (thirty-five patients) in which a well fixed femoral component that originally had been implanted with use of a so-called first-generation cementing technique was subsequently left in place at the time of revision of the acetabular component without cement. The purpose of the study was to determine the rate of survival of the femoral component and the complications associated with revision of one side of the joint. The femoral components had been in situ for a mean duration of 102 months (range, twelve to 216 months) at the time of the revision of the acetabular component. At the time of follow-up after the revision of the acetabular component, one patient (one femoral component; 3 per cent) had died, twenty-seven femoral components (73 per cent) were in place and radiographically stable, one femoral component had been removed because of infection, six (16 per cent) had been revised because of aseptic loosening, and two (5 per cent) were definitely loose according to radiographic criteria. Excluding the failures and death, the mean duration of follow-up was sixty-five months (range, forty-eight to 121 months). The predicted survival of the femoral component after the revision of the acetabular component was 88 per cent (95 per cent confidence interval, 82 to 94 per cent) at forty-eight months and 78 per cent (95 per cent confidence interval, 67 to 89 per cent) at eighty-eight months. Dislocation occurred in three hips (8 per cent), and a trochanteric non-union occurred in five (14 per cent). The mean rate of linear polyethylene wear did not differ significantly (0.13 as compared with 0.12 millimeter per year; p = 0.74) from that for a comparable group of forty-nine hips that had had a revision of the femoral component without cement and had been followed for a similar duration. The data support the decision to retain a well fixed femoral component that has been implanted with a so-called first-generation cementing technique when the acetabular component subsequently needs a revision. The survival of the femoral component and the risk of associated complications do not appear to be appreciably altered by revision of the other side of the joint.

Acetabulum↗

Complications of a cable grip system.

From a group of 643 total hip arthroplasties, 98 patients required trochanteric osteotomies, and in 68 the trochanteric osteotomies were repaired with the Dall-Miles cable grip system (Howmedica, Rutherford, NJ). Trochanteric nonunion occurred in 17 of these patients (25%), with fraying and fragmentation of the cable present in 15 (88%). Of the 51 patients with radiographic union, 18 (35%) also had signs of fraying and fragmentation. Bone destruction around the cable in the area of the lesser trochanter was seen in seven patients (10%). Large deposits of metal debris at the inferior border of the acetabulum were seen in eight hips (12%). Multifilament cable did not appear to offer significant advantages over standard monofilament wire, and the potential problems of fraying, fragmentation, and free-floating metallic debris must be considered.

Adult↗

Primary noncemented total hip arthroplasty in patients with ankylosing spondylitis. Clinical and radiographic results at an average follow-up period of 6 years.

Twenty consecutive primary noncemented total hip arthroplasties performed on 12 men with ankylosing spondylitis were available to be studied clinically and radiographically at an average follow-up period of 75 months (range, 27-121 months). The average patient age at the time of surgery was 35 years (range, 23-53 years). Harris hip scores averaged 48.4 before surgery and 89.1 at the most recent follow-up examination. Significant improvements in pain, function, and range of motion were observed following total hip arthroplasty. No hip has required a surgical revision or reoperation. Heterotopic ossification was observed in 6 of 14 hips (43%) in the ankylosing spondylitis patients who had not had any perioperative prophylaxis for heterotopic bone formation. By contrast, 43 of 49 hips (88%) demonstrated heterotopic bone formation in a well-defined control group of 45 men with other diagnoses undergoing the same procedure by the same group of surgeons at the same institution. During the same period using the same implants. A thorough review of the literature and data from the institution does not support the notion that ankylosing spondylitis patients are necessarily predisposed to form heterotopic ossification. The use of routine perioperative prophylaxis for heterotopic ossification may not be warranted in all patients with ankylosing spondylitis undergoing routine primary noncemented total hip arthroplasty.

Adult↗

Primary total hip arthroplasty using noncemented porous-coated femoral components in patients with osteonecrosis of the femoral head.

Ninety consecutive total hip arthroplasties in 73 patients with osteonecrosis of the femoral head yielded 81 hips in 64 patients (37 men and 27 women) available for evaluation after a 4-8-year follow-up period. The average age at surgery was 39.9 years (range, 20-66 years). Osteonecrosis etiology was idiopathic in 13 hips, alcohol-induced in 15, femoral neck fracture in 12, and slipped capital femoral epiphysis in 2. The remaining 39 cases were related to steroids, which were administered for a variety of reasons. Two types of noncemented, porous-coated, straight-stem femoral components and three types of acetabular components were utilized. Good or excellent clinical results were recorded in 80.2% of the patients. Average Harris hip scores improved from 52.9 to 87.9 points. Nine patients required revision of at least one component and were significantly younger than those with unrevised components. A revision rate of 24.1% was recorded in patients under 35 years of age at the time of primary surgery. Good or excellent clinical results were seen in 92.3% of the idiopathic cases, 86.7% of the alcohol-induced cases, 77.8% of the renal transplant cases, and 62.5% of the systemic lupus erythematosus cases. The overall mortality rate at the follow-up evaluation was 14%; it was 50% in renal transplant patients. Analysis of the clinical results based on the implants showed no significant differences in Harris hip scores or pain and function scores. While total hip arthroplasty using noncemented porous-coated femoral stems appears to give better results than cemented procedures in patients with osteonecrosis of the femoral head, the results appear to be inferior to those reported in patients with other diagnoses.

Adult↗

Revision of the acetabular component without cement after total hip arthroplasty. Three to six-year follow-up.

One hundred and thirty-eight consecutive revisions of an acetabular component were performed in 132 patients between 1983 and 1986. The revision prosthesis was a hemispherical component that was coated with porous titanium mesh and was secured to the pelvis with a variable number of screws. There were seventy-five women and fifty-seven men, and the mean age at the time of the revision was fifty-two years (range, twenty to seventy-nine years). Due to defects in the acetabulum, 80 per cent of the hips were treated with bone grafts, usually a mixture of local autogenous graft and freeze-dried allograft. One hundred and twenty-four patients (129 hips) were available for follow-up, at a mean of forty-four months (range, thirty-six to eighty months). Seven hips (5 per cent) were revised again: four because of infection and three because of instability. There were no revisions for loosening without infection, and none of the components migrated in the absence of infection. Radiolucent lines were common and usually corresponded to regions in which allograft had been used. All bone grafts united by twelve months. Non-contained medial grafts underwent a phenomenon of resorption, consolidation, and remodeling to a sclerotic rim by twenty-four months. There were no complications related to placement of the screws. The results in this series were superior to results of revisions of acetabular components with the use of cement, which were associated with rates of failure of almost 10 per cent after a similar duration of follow-up. The technique of maximization of host-bone coverage and of packing of all defects with cancellous autogenous graft or allograft, or both, was successful for all classes of acetabular deficiencies.

Acetabulum↗