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Biomedical subjects

J J Callaghan

Publications and source records attributed to J J Callaghan.

At least 127 records · Page 7Linked to original sources

Screw-augmented fixation of acetabular components. A mechanical model to determine optimal screw placement.

Sixteen embalmed hemipelves were used to determine the optimal acetabular screw placement to provide maximal screw pull-out strength in unicortical and bicortical screw fixation. The anterior column, superior ilium, posterior column, ischium, and pubis regions of the pelvis were tested using 6.5-mm titanium alloy screws and a hydraulic servo-controlled 1321 Instron testing machine. Force vs displacement data were acquired. Bicortical fixation was stronger than unicortical fixation in the four zones compared. This difference was significant in the superior ilium, posterior column, and ischium. The anterior column could not accept unicortical screws due to inadequate bone depth, which ranged between only 6 mm and 10 mm. Bicortical fixation was significantly greater in the superior ilium, posterior column, and ischium than in the anterior column or pubis. Unicortical fixation was greatest in the superior ilium. This information may aid decisions concerning the positioning of screws to augment acetabular component fixation.

Acetabulum↗

Paget's disease of the patella.

Five patients with Paget's disease involving the patella were evaluated for the following radiographic features: trabecular pattern, cortical integrity, density, and size of the affected patella. Radiographic appearances consisted of minimal trabecular coarsening in the patella of nearly normal size and progressed to considerable cortical thickening and osteoblastic remodeling in a dramatically enlarged patella. The radiologic features of Paget's disease of the patella are distinctive and should obviate biopsy.

Adult↗

Fatal fat embolism following total condylar knee arthroplasty.

Although fatality from fat emboli syndrome following total knee arthroplasty has been reported, most cases occurred following the insertion of hinged prostheses and few are documented with detailed pathology. The authors present the case of a 75-year-old patient with long-standing rheumatoid arthritis who underwent a total condylar type total knee arthroplasty procedure using an intramedullary femoral alignment system and expired 6 hours following surgery. On autopsy he had multiple organ involvement with fat emboli. Especially with the present use of intramedullary alignment systems and the increasing numbers of one-stage bilateral total knee arthroplasty procedures the potential for this problem must be recognized so that early therapy can be instituted.

Aged↗

Posterior labral tear as a block to reduction in an anterior hip dislocation.

The patient presented with an anterior dislocation of the hip that could not be centrically reduced by closed methods. Computed tomographic imaging after trial reduction revealed a posterior fragment that was limiting reduction. At the time of open reduction, a large posterior labral tear with a small avulsed posterior acetabular rim of bone was found to be blocking the reduction.

Adult↗

Assessing the results of hip replacement. A comparison of five different rating systems.

One hundred hips in patients who had had primary uncemented replacements were followed up for one or two years, and assessed by five different methods. All produced different results. The Hospital for Special Surgery rating produced the most optimistic assessment and the Merle d'Aubigné rating the most pessimistic. The functional class of the patients, as defined by Charnley in 1979, significantly affected the ratings, and these should clearly be included in all rating systems. Moreover, if systems are to be compared, they should all use descriptive words, such as limp or pain, in precisely the same way.

Adult↗

The effects of exposure of articular cartilage to air. A histochemical and ultrastructural investigation.

The effects of exposure of articular cartilage to air and the potential for reversibility of the histological and ultrastructural changes that were produced by this exposure were investigated in the knee joint of the rabbit. After a medial parapatellar arthrotomy and lateral dislocation of the patella, the surface of the articular cartilage was exposed to air for one, two, and three hours in forty-five rabbits. Reversibility of the changes was assessed in fifteen rabbits after exposure of the cartilage to air for three hours, closure of the joint, and six weeks of recovery. Histochemical and ultrastructural changes were evaluated, with use of the contralateral non-exposed knee joint as a control. Depletion of glycosaminoglycans in the matrix of articular cartilage, as indicated by a loss of surface staining with toluidine blue, occurred after one hour of exposure to air. Ultrastructural changes occurred in chondrocytes throughout the full thickness of articular cartilage after one hour of exposure. Increases in the time of exposure to air resulted in more pronounced ultrastructural abnormalities in chondrocytes throughout the entire thickness of the articular cartilage, but there was no apparent irreversible cellular injury. Six weeks after arthrotomy, the chondrocytes had fully recovered from the changes that had been noted immediately after exposure to air, and they were devoid of degenerative changes. The cells showed ultrastructural evidence of increased metabolic activity in the nucleus and cytoplasm. In addition, the chondrocytes had partially restored the depleted glycosaminoglycans.

Air↗

The acetabulum: a prospective study of three-phase bone and indium white blood cell scintigraphy following porous-coated hip arthroplasty.

Although few studies address the use of three-phase bone scanning (TPBS) and indium-111-labeled white blood cell scintigraphy (111In-WBC) in hip arthroplasty utilizing a porous-coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ form that seen with the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous-coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and 111In-WBC at approximately 7 days, and 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the acetabulum. All 25 prostheses (144 of 144 scans) demonstrated increased uptake on the bone-phase images. Although this activity decreased with time, 76% had persistent uptake at 24 mo. Twenty-three of 25 prostheses (126 of 140 scans) showed increased uptake on 111In-WBC scintigraphy, invariably decreasing with time, but with 37% having significant uptake at 24 mo. Scintigraphic patterns in the uncomplicated porous-coated hip arthroplasty patient appear to differ from patterns described in cemented prostheses.

Acetabulum↗

Endosteal erosion in association with stable uncemented femoral components.

Sixteen cases of patients who had focal femoral osteolysis after total hip replacement without cement were identified. Fourteen of them were included in a retrospective review of 474 consecutive total hip replacements without cement in 441 patients who had been followed for at least two years. The criteria for inclusion in the study were focal osteolysis with a femoral component that appeared stable radiographically, and no subsidence or change of position of the implant. All but two patients were men and were quite active. The average age was forty-seven years (range, twenty to sixty-five years). Fourteen of the sixteen patients had an excellent clinical result (a Harris hip score of 90 points or more). In two patients, the hip replacement was revised and, in a third, a biopsy was done. In all three patients, the implant was found to be firmly fixed to the femur. In the two hips that were revised, extensive ingrowth of bone was demonstrated histologically, there was no evidence of infection, and a well defined fibrous membrane was found around the smooth portion of the stem. The histological specimens from these two hips contained focal aggregates of macrophages with particulate polyethylene and metallic debris. In the biopsy material from the hip that was not revised, a fine fibrous membrane lined a cystic cavity. Although the membrane contained an occasional macrophage, no foreign material was identified. Trabecular microfracture and osteoclastic resorption of bone were seen next to the fibrous lining. With one exception, osteolysis was not identified less than two years postoperatively. In most patients, osteolysis appeared after three years. This study showed that femoral osteolysis can occur around uncemented components.

Adult↗

The relationship of the intrapelvic vasculature to the acetabulum. Implications in screw-fixation acetabular components.

The use of screw-fixation acetabular components in total hip arthroplasty could increase the incidence of vascular injury because of the increased use of drills and screws placed into the acetabulum in close proximity to major vessels. Analysis of two illustrative case studies, anatomic specimen cross sections, and computed tomographic scans demonstrate which vessels are at risk of injury should the inner cortex of the pelvis be penetrated. The iliac vessels are at risk of injury when penetration of the inner cortex of the pelvis occurs in the anterosuperior region of the acetabulum. The obturator vessels are at risk when penetration occurs in the anteroinferior quadrant of the acetabulum. The vessels can be within 0.5 cm of the inner cortex of the pelvis and tend to become closer with advancing age. Damage to the intrapelvic vessels may cause profound blood loss and hypotension when screw-fixation acetabular components are used. Rapid identification and immediate surgical repair of vessel lacerations are essential in the treatment of this complication.

Acetabulum↗

Pyomyositis in a temperate climate. Presentation, diagnosis, and treatment.

The cases of eighteen patients who were treated for pyomyositis between 1970 and 1988 were evaluated. The diagnosis was often delayed because other primary diagnoses were considered, including muscle strain, synovitis, thrombophlebitis, and neoplasm, and because the symptoms were vague and prolonged (maximum duration, one year). The muscles around the hip and thigh were most commonly involved (twelve patients), and Staphylococcus aureus most commonly grew on culture (twelve patients). Computed tomography aided in the accurate diagnosis of the infection and of the extent of involvement. Incision, drainage, and antibiotic therapy eradicated the infection in all patients, and they had no residual functional limitations and minimum residual symptoms.

Adolescent↗

Primary tumors of the patella. A review of 42 cases.

This study reports 42 cases of histologically proven and radiographically correlated primary patellar tumors. Despite diverse histologic diagnoses, the radiographic appearances of benign as opposed to malignant patellar neoplasms are essentially indistinguishable. Although the literature suggests that giant cell tumor is the most frequent benign tumor of the patella, the most common benign neoplasm in this series is chondroblastoma (16 cases). Only four primary malignant lesions were encountered, three cases of lymphoma and one case of hemangioendothelioma. Since 38 (90%) of the 42 cases were benign, a benign etiology should be strongly favored, notwithstanding the radiographic appearance, whenever a primary patellar tumor is encountered.

Adolescent↗

Radiographic measurements in protrusio acetabuli.

The radiographic data of 48 hips in 40 patients with painful, progressive protrusio acetabuli treated with cemented total hip arthroplasty and medial acetabular reinforcement using autologous or homologous bone grafts were reviewed. Twelve separate measurements were performed on the preoperative, postoperative, and most recent radiographs of each case to determine which measurements were the most useful in diagnosing protrusio acetabuli and in following preoperative and postoperative migration. The minimum follow-up period was 10 years (mean, 12.3 years). Vertical migration and horizontal distance, two measurements utilizing an X-Y coordinate system based on the acetabular teardrop, were found to be most useful. The cases with postoperative progression demonstrated vertical migration more often than medial migration.

Acetabulum↗

Nonoperative treatment of a postoperative fracture around an uncemented porous-coated femoral component.

Ipsilateral femur fractures in patients who have had cemented total hip arthroplasty is an infrequent and hazardous complication. Operative treatment has been specifically recommended for type II fractures (those extending from the proximal portion of the femur shaft to beyond the distal tip of the prosthesis) because of the predictably unsatisfactory results with nonoperative treatment. The authors report the successful nonoperative treatment of a postoperative fracture around an uncemented porous-coated femoral component. They recommend nonoperative treatment for minimally displaced type II femoral shaft fractures around uncemented porous-coated prostheses.

Casts, Surgical↗

Three-phase bone scan and indium white blood cell scintigraphy following porous coated hip arthroplasty: a prospective study of the prosthetic tip.

Although few reports address the use of three-phase bone scanning (TPBS) and 111In-labeled white blood cell (In-WBC) scintigraphy in hip arthroplasty utilizing a porous coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ from that seen in the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and In-WBC at approximately 7 days, and at 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the prosthetic tip. Only one of 136 flow studies were abnormal and only two of 136 blood-pool images demonstrated focally increased activity. All 25 prostheses (120 of 143 scans) demonstrated increased uptake on the bone phase images. The area about the tip was divided into three segments; increased uptake at 24 mo was noted in the medial, distal, and lateral segments in 16%, 72%, and 56% of prostheses, respectively. Twenty of 25 prostheses (82 of 142 scans) showed uptake on In-WBC scintigraphy, being noted in 48% of prostheses at 24 mo. We conclude that scintigraphic patterns in the uncomplicated patient with a porous coated prosthesis appear to differ from patterns described in cemented prostheses.

Adult↗

Cardiac isoenzyme values after total joint arthroplasty.

The purpose of this study was to prospectively determine what effect total joint arthroplasty had on the myocardial-associated isoenzymes of serum creatine kinase (CK-MB) and lactate dehydrogenase (LD-1:LD-2). Fifty patients treated with total joint arthroplasty of the hip or knee had isoenzyme determinations using automated spectrophotometry and agarose gel electrophoresis. Skeletal muscle injury associated with the trauma of surgery resulted in significant elevations of the absolute value of CK-MB; however, the percentage of CK-MB comprising total CK activity and LD-1:LD-2 did not rise significantly in patients who did not experience postoperative myocardial infarction. It is important to determine both serum CK-MB and LD-1:LD-2 in suspected postoperative myocardial infarction since false positive elevations of CK-MB can occur. Elevations of CK-MB exceeding 50 International Units/liter or 5% of the total CK activity combined with LD-1:LD-2 exceeding 1.0 should not be attributed to skeletal muscle injury alone following total joint arthroplasty of the hip or knee.

Adult↗