Search PubMed⌕ Search

Biomedical subjects

J J Callaghan

Publications and source records attributed to J J Callaghan.

At least 91 records · Page 5Linked to original sources
PubMed1995

Fracture of the acetabulum during insertion of an oversized hemispherical component.

A hemispherical metal-backed acetabular component that was oversized by two or four millimeters was introduced without cement into thirty fresh or embalmed cadaveric acetabula that were fifty, fifty-two, fifty-four, fifty-six, or fifty-eight millimeters in diameter. Manual tapping was used to insert the component into ten fresh and ten embalmed specimens, and a materials testing machine was used for the remaining five fresh and five embalmed specimens. The magnitude of force and the number of pulses necessary to seat the component were determined for the insertions performed with the materials testing machine; 2000 and 3000 newtons of force were required to insert the cups that were oversized by two and four millimeters, respectively. Visual and radiographic assessments were used to identify any resulting acetabular fractures. Over-all, eighteen (60 per cent) of the thirty acetabular specimens fractured. Of the eighteen fractures, only fifteen were detectable radiographically: ten on en face or lateral radiographs of the cup and five only on oblique radiographs of the cup. The remaining three fractures were apparent only after the removal of the acetabular component.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetabulum↗
PubMed1995

Revision of total hip arthroplasty in octogenarians.

Twenty-seven revision total hip arthroplasties were performed in patients who were at least eighty years old. The average duration of follow-up was five years. There were no perioperative deaths, and only 11 per cent (three) of the patients had a major complication; all of the complications resolved. The only re-revision was the placement of an extended lip-liner for the treatment of recurrent dislocation. Of the twenty-five patients who were alive at the time of the most recent follow-up or who had been survived by a family member who could be interviewed, twenty-one (84 per cent) said that the operation had improved function, twenty-three (92 per cent) had less pain, and twenty-two (88 per cent) were satisfied with the result.

Activities of Daily Living↗
PubMed1995

Early loosening of the femoral component at the cement-prosthesis interface after total hip replacement.

Between 1980 and 1990, 1941 total hip replacements were performed with use of the Iowa femoral component fixed with cement. Twenty-seven of these patients (twenty-nine hips) had early loosening of the femoral component two to ten years (average, five years) after the operation. The average age of these patients at the time of the operation was fifty-nine years (range, forty-one to seventy-seven years). The acetabular cup had been inserted without cement in seventeen hips, and the cup had been inserted with cement in twelve. The femoral stems had a matte finish; twenty had been precoated with polymethylmethacrylate and nine had not been precoated. The pattern of loosening of the femoral stem was unique: in each hip, the loosening was initially reflected by debonding (a superolateral lucency between the cement and the prosthesis in zone 1 of Gruen et al.), and this was followed by progressive loosening at the cement-prosthesis interface with maintenance of the bone-cement interface. In twenty hips, the debonding was followed by extensive osteolysis. Twenty patients (twenty-one hips) had a revision, and one was considering a revision at the time of writing. The average time from the onset of the symptoms to the revision for the nineteen hips for which this information was available was nine months. We believe that both the geometry (a cylindrical shape distal to the proximal cobra shape) and the surface finish of the Iowa femoral component were responsible for the pattern of progressive loosening.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

A model of cortical window healing in the rabbit.

A rabbit femur cortical window model was developed to study the time-dependent mechanical and radiographic changes with various treatments of surgically created windows. In the present experiment the time-dependent differences in torsional whole bone strength between femora treated with window replacement and those treated without replacement were evaluated. The 3.175 mm diameter windows were surgically created with a power trephine at the lateral femoral isthmus unilaterally, with the contralateral femur serving as a paired control. In one group of animals the window was reconstructed by replacement of the excised cortical plug while in the other group the window was left unreplaced. Each group was divided into three subgroups sacrificed at 3, 6, and 9 weeks postoperatively. Lateral radiographs were obtained immediately prior to sacrifice. After sacrifice bilateral femora were harvested and loaded to failure on a torsional testing apparatus to obtain values for ultimate torque, maximum angle of deformation, and energy capacity expressed as percent of paired control. Replacement resulted in significantly greater whole bone strength (P < .041), and strength increased significantly with time (P < .006). Radiographic appearance correlated significantly with both treatment and time, but not strength. The model was sensitive to both treatment-dependent and time-dependent effects, demonstrating potential for evaluation of other cortical window treatments.

Animals↗
PubMed1995

Results of cemented femoral revision total hip arthroplasty using improved cementing techniques.

Seventy-nine consecutive femoral component revision total hip arthroplasties done in 73 patients from 1977 to 1983 using a distal intramedullary cement plug and a cement gun delivery system were evaluated to determine if improved results were obtained with newer cementing techniques. At a minimum 10-year followup interval, only 1 patient was not available for followup and 47 hips had minimum 10-year followup radiographs. The incidence of femoral rerevision for aseptic loosening was 9.5% for those hips with minimum 10-year followup and 5.4% for the entire group. The incidence of radiographic femoral failure (defined as a revision or definite or probable loosening) was 26.1% for those hips followed for a minimum of 10 years and 16.3% for the entire group. Compared with historical controls, these results represent an improvement over those reported with the use of earlier cementing techniques.

Adult↗
PubMed1995

Changes on magnetic resonance images after traumatic hip dislocation.

Fourteen patients with traumatic hip dislocation had serial magnetic resonance imaging and routine radiographic studies from the time of injury through 24 months after injury. One experienced radiologist interpreted all images prospectively for abnormalities suggesting osteonecrosis of the femoral head and posttraumatic arthritis. Eight hips demonstrated abnormal marrow signals on T1 and T2 weighted images within 6 weeks of injury. These changes progressed in 3 hips, and osteonecrosis was confirmed subsequently by plain radiography. The abnormal marrow signals in the remaining 5 hips proved to be transient, resolving on magnetic resonance images within 3 months in 4 of the 5 patients. Magnetic resonance imaging can be used with confidence for the early detection of osteonecrosis of the femoral head after traumatic hip dislocation or fracture-dislocation. The presence of acetabular or femoral shaft hardware did not preclude magnetic resonance imaging assessment of these patients when coronal, sagittal, and axial images were obtained. Magnetic resonance imaging was not reliable for assessing marrow changes within the first week after injury, nor was it helpful in predicting which patients were at risk for posttraumatic arthritis to develop. An algorithm is proposed for using magnetic resonance imaging in the early diagnosis of osteonecrosis of the femoral head after traumatic hip dislocation.

Adolescent↗
PubMed1995

Concerns and improvements with cementless metal-backed acetabular components.

The relatively high incidence of acetabular component failure shown in long-term followup studies of cemented total hip replacement has led to the use of noncemented fixation on the acetabular side of the total hip arthroplasty. In the first generation of noncemented acetabular devices, large-size femoral heads requiring thinner polyethylene were used with many of the popular designs. These components were also modular, but the design considerations involved in minimizing polyethylene debris were not fully appreciated. The newer designs of noncemented acetabular components are addressing the need to minimize wear and the production of particulate debris at the bearing surface and metal-polyethylene interface. Newer techniques also have been developed to provide initial component stability and bone-prosthesis contact. With these improvements, the results of noncemented acetabular fixation may outperform the results with cemented fixation. This may be especially true when considering the ease of insertion and versatility of noncemented acetabular components.

Acetabulum↗
PubMed1995

Radiographic measurement of wear in 5 cohorts of patients observed for 5 to 22 years.

Standardized wear measurements using a tablet digitizer were made on long-term serial radiographs for 5 cohorts of total hip replacements to determine any differences in acetabular component polyethylene wear rates. The 5 groups included 4 cemented acetabular component series and 1 cementless acetabular component series. Comparing the rates of linear wear for the 5 groups, 22-mm-head components had similar wear when compared with the 28-mm-head components, both cemented and uncemented, and volumetric wear rates were greater for the cemented 28-mm-head components than for the 22-mm-head components. Although molded 22-mm-head components had less wear than the machined 22-mm-head components, there was no statistically significant difference between the 2. The uncemented metal-backed component with 28-mm-head articulation showed no accelerated wear when compared with the cemented metal-backed components at a shorter 5-year followup. The constant variable in all series was a cemented femoral component.

Adult↗
PubMed1995

Osteolysis around an uncemented cobalt chrome total hip arthroplasty.

One hundred consecutive uncemented Porous Coated Anatomic total hip arthroplasties performed in 91 patients who obtained prospective serial clinical and radiographic evaluation during a minimum 7-year followup period were studied for the occurrence, extent, and progression of localized periprosthetic bone loss (osteolysis). Periprosthetic bone loss occurred around the femoral component in 11 hips, the acetabular component in 2 hips, and both components in 2 hips during the followup interval. The bone loss was progressive in 6 hips (2 of 11 femoral cases, 2 of 2 acetabular cases, and 2 of 2 both component cases). It frequently occurred around components that showed no evidence of acetabular migration or femoral subsidence (11 of 15 cases). The average age at surgery of patients in the bone loss group was 10 years younger than the nonbone loss group (in the 100 hip cohort). Clinically, most patients with bone loss were asymptomatic, with the average Harris hip rating of 92.4 points (range, 85-99 points). With this particular device at this interval of followup (7 years), the acetabular and the proximal femoral osteolytic lesions are of greatest concern. Wear of the acetabular component was greater for cases with osteolysis than for those without osteolysis, but the difference was not significant.

Adult↗
PubMed1994

Total hip arthroplasty with cement in patients who are less than fifty years old. A sixteen to twenty-two-year follow-up study.

Eighty-nine Charnley total hip arthroplasties were performed with cement, by a single surgeon, in sixty-seven patients who were less than fifty years old at the time of the procedure. The follow-up period ranged from sixteen to twenty-two years (average, eighteen years). The most recent evaluation consisted of a clinical and a radiographic examination for forty-six patients (fifty-eight hips), a telephone interview and a review of the most recent radiographs for eleven patients (sixteen hips), and a telephone interview only for six patients (ten hips). Four patients (five hips) were lost to follow-up. Eleven (13 per cent) of the eighty-four hips that were followed were revised because of aseptic loosening of the acetabular implant, and two hips (2 per cent) were revised because of aseptic failure (loosening or fracture) of the femoral component. When the number of hips that were revised was combined with the number of hips in which there was radiographic evidence of failure, the rate of loosening of the acetabular component was 50 per cent (forty-two hips) and the rate of failure of the femoral component was 8 per cent (seven hips). Three hips had recurrent dislocations after the operation; none of the three was revised. One patient (two hips) had Grade-III heterotopic ossification according to the system of Brooker et al.; no other patient had more than Grade-II heterotopic ossification. Nine hips had a trochanteric non-union without migration of the trochanter.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetabulum↗
PubMed1994

The results of improved cementing techniques for total hip arthroplasty in patients less than fifty years old. A ten-year follow-up study.

Thirty-six patients (forty-two hips) in whom so-called second-generation cementing techniques, such as medullary lavage, use of an intramedullary cement plug, hand-mixing of the cement, and use of a cement gun to deliver the cement in a doughy state in a retrograde fashion, had been used for a primary total hip arthroplasty were evaluated at an average of eleven years (range, ten to fifteen years) after the operation. All of the patients had been less than fifty years old at the time of the operation. Thirty-one patients were evaluated by clinical and radiographic examinations and five, by a telephone interview. Twelve components (ten acetabular components [24 per cent] and two femoral components [5 per cent]) in ten hips had been revised for aseptic loosening. An additional five acetabular components (12 per cent) and five femoral components were definitely loose according to radiographic criteria. Three of these femoral components were polished stems that were considered loose only because of the presence of a radiolucent line, 0.5, one, and two millimeters wide, at the prosthesis-cement interface in zone 1 of Gruen et al. The other two loose stems were in patients who were receiving renal dialysis. These findings demonstrate excellent fixation of the femoral component but continued problems with fixation of the acetabular component despite the use of improved cementing techniques.

Activities of Daily Living↗