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Biomedical subjects

W J Hozack

Publications and source records attributed to W J Hozack.

At least 37 records · Page 2Linked to original sources

Simultaneous bilateral versus unilateral total knee arthroplasty. Outcomes analysis.

One hundred consecutive, primary simultaneous bilateral total knee arthroplasties were prospectively compared with 100 consecutive, primary unilateral total knee arthroplasties in reference to relative risk, complications, cost, and need for rehabilitation. All procedures were performed using identical preoperative, intraoperative, and postoperative protocols. Postoperative confusion was approximately four times greater in the simultaneous bilateral total knee arthroplasties group (29% versus 7%), which was thought to represent an increased incidence of fat embolism. Cardiopulmonary complications were approximately three times greater after simultaneous bilateral total knee arthroplasties (14% versus 5%), and most commonly involved arrhythmias. The increased stress on the cardiopulmonary system with simultaneous bilateral total knee arthroplasties may make this procedure contraindicated in certain patients with preexisting disease. There was an approximately 17 times greater need for banked blood in the simultaneous bilateral total knee arthroplasties group (17% versus 1%), which is alarming given the persistent concerns of transfusion related disease transmission. Although the length of hospitalization was similar (6.4 days simultaneous bilateral total knee arthroplasties versus 6 days unilateral total knee arthroplasty), 89% of the patients in the simultaneous bilateral total knee arthroplasties group required a rehabilitation stay versus 45% of the patients in the unilateral total knee arthroplasty group. Total hospital charges averaged $53,168 for simultaneous bilateral total knee arthroplasties versus $32,598 for unilateral total knee arthroplasty. Total rehabilitation charges were similar. The relative cost savings implicit by doing simultaneous bilateral total knee arthroplasties seem to be at least partially offset by the approximately two times greater need for rehabilitation in this group. The true safety, efficacy, relative risk, and total cost analysis of simultaneous bilateral total knee arthroplasties demands further critical evaluation.

Adult↗

Treatment of femoral osteolysis with cementless total hip revision.

Fifty-nine total hip revision arthroplasties using cementless femoral components were performed in patients with focal femoral osteolytic defects before surgery. Clinical and radiographic review was performed at 2 to 5 years of follow-up evaluation. Osteolytic defects were located by Gruen zones, evaluated on postoperative radiographs, and classified as stabilized, progressive, regressing, healed, or new. There were no clinical failures in this series of patients, and no femoral revisions have been necessary. Progression of the lytic defects after revision did not occur. No new defects developed. Of the 154 preoperative osteolytic defects identified, 27 stabilized, 65 regressed, and 62 healed. One goal of revision hip surgery is to prevent osteolytic lesions from progressing, and this was achieved in 100% of patients in this series. Another goal of revision surgery is restoration of bone stock. It appears that there is a slow, steady remodeling of the lytic lesion that occurs with a well-fixed porous ingrowth prosthesis. Although this series did not show any additional benefit from cancellous allografting, the grafting technique did not use specifically designed instrumentation. Therefore, the full potential of grafting may not have been realized. If severe osteolysis is present, then regression or healing of defects can be achieved by revision to a cementless femoral component with or without the addition of cancellous allograft.

Adult↗

Head-neck modularity for total hip arthroplasty. Is it necessary?

Although modular head-neck combinations for femoral components are convenient and useful, theoretical concerns make them less attractive. In a consecutive series of 100 primary cementless total hip arthroplasties, the neck length chosen for the broach trial reduction was compared with the final neck length chosen after the actual femoral component had been impacted. In 19%, the neck length was changed after insertion of the femoral component. As a result, leg-length inequality or wastage of these femoral components would have resulted. For cementless femoral components, the ability to adjust neck length after component impaction remains important.

Biomechanical Phenomena↗

Radiographic cost reduction strategy in total joint arthroplasty. A prospective analysis.

A consecutive series of 222 patients who underwent cemented total knee arthroplasty (124) and uncemented total hip arthroplasty (98) were evaluated prospectively. The purpose of this study was to determine if routine radiologic interpretation of postoperative total hip and total knee radiographs is cost effective. Also, the study was designed to determine if routine predischarge radiographs, in conjunction with recovery room radiographs, are worthwhile. There were no changes in postoperative patient management based on orthopaedic or radiologic review of either radiograph. No additional information was gained from review of the radiologic evaluations. Therefore, obtaining one series of routine inpatient postoperative total joint radiographs and eliminating postoperative radiologic consultation will significantly reduce costs without compromising patient care.

Cost Savings↗

Incidence of thigh pain after uncemented total hip arthroplasty as a function of femoral stem size.

Two hundred seventy-one patients (297 primary total hip arthroplasties) were evaluated for thigh pain 2 years after surgery. All femoral components were identical in wedge-shaped geometry but differed in size. All components were radiographically stable. Regression analysis revealed the presence of thigh pain to be directly correlated to increasing stem size (P = .014, r = .857). An even more significant positive correlation to thigh pain was present for proximal and distal component moments of inertia for bending in the mediolateral plane. Femoral stem size has a significant effect on the incidence of thigh pain.

Aged↗

Treatment of early symptomatic pulmonary embolism after total joint arthroplasty.

The purpose of this study was to evaluate the risk of intravenous heparin therapy or the use of Greenfield filters (Meditech, Watertown, MA) in the early postoperative period in patients who have documented symptomatic pulmonary embolism. Symptomatic pulmonary embolism in the first weeks was identified in 52 patients. Twenty-four patients were treated with Greenfield filter insertion and 28 patients with intravenous heparin therapy. One complication associated with insertion of the Greenfield filter-premature opening in the internal jugular vein-resulted in no adverse consequences. Three complications were associated with intravenous heparin therapy: one transient thrombocytopenia, one recurrent symptomatic pulmonary embolism, and one knee hematoma, which did not require surgical evacuation. It appears that Greenfield filter insertion is a viable option for treatment of symptomatic pulmonary embolism in the early postoperative period after total joint arthroplasty. In contrast to other published data, this study suggests that intravenous heparin therapy may also be a reasonable alternative, but is a treatment regimen that requires careful monitoring of platelets, wound complications, and bleeding parameters.

Adult↗

Heterotopic ossification. Incidence in cemented versus cementless total hip arthroplasty.

To resolve the debate whether cementless total hip arthroplasty (THA) carries an increased risk of heterotopic ossification (HO) as compared with cemented THA, 100 patients undergoing primary cemented THA (both acetabulum and femur) were individually matched to 100 patients undergoing primary cementless THA. Preoperative, 6-week postoperative, and 2-year postoperative radiographs were reviewed for the presence of HO using the Brooker classification. No subject in either group received any postoperative prophylaxis for HO. The matching parameters were age ( +/- 10 years), sex, weight ( +/- 10 lb.), diagnosis (all were osteoarthritis), Charnley class (A/B), and surgical approach (trochanteric osteotomy or modified Hardinge). The overall incidence of HO was 68% in the cemented group and 65% in the cementless group. The extent of HO (grade III) was significant in 9% of the cemented group and 5% of the cementless group. There was no grade IV HO (bone ankylosis) in either group. Neither the overall incidence nor the incidence of grade III HO was statistically different between the two groups. Patient sex and surgical approach had no interactive effect with type of component fixation on the incidence of HO. Fear of HO should not be a factor in the choice of fixation for THA.

Aged↗

Relationship between polyethylene wear, pelvic osteolysis, and clinical symptomatology in patients with cementless acetabular components. A framework for decision making.

The purpose of this study is to assess the relationship between acetabular component polyethylene wear, pelvic osteolysis, and clinical symptoms to determine when operative intervention should occur and to predict the degree of difficulty of the revision. Fifty-four revisions of failed cementless acetabular components were performed in 52 patients. All cases demonstrated polyethylene wear radiographically, and in 43 cases (80%), osteolysis of the pelvis was seen. Symptoms of groin or buttock pain were seen in 45 of 54 cases (83%). Preoperative staging of the disease process included one patient with wear radiographically but neither symptoms nor lysis (stage I), 10 patients with wear and pain (stage IIA), 8 patients with wear and lysis but no pain (stage IIB), and 35 patients with wear, lysis, and pain (stage III). Patients in stages I and IIA could be revised with cementless components without structural allograft. Patients in stages IIB and III required structural allograft in 79% and cemented components in 53%. Cemented components were used when there was less than 50% contact between host-bone and prosthesis. Polyethylene wear alone (stage I) is an indication of impending failure, and when symptoms develop (stage IIA), revision should be undertaken. The development of radiographic lysis is a critical event, and as soon as osteolysis develops (stage IIB or III), revision should be undertaken immediately. From the perspective of the revision surgeon, there is great value in the early intervention for polyethylene wear and pelvic osteolysis.

Acetabulum↗

Hydroxyapatite-coated femoral stems. A matched-pair analysis of coated and uncoated implants.

Fifty-two pairs of patients who had had a total hip arthroplasty with a porous-coated femoral implant were studied in a retrospective, matched-pair analysis. Half of the patients had received a femoral component coated with hydroxyapatite and the other half (the controls), an identical component but without hydroxyapatite. The patients were matched for age, sex, weight, diagnosis, Charnley class, operative approach, and duration of follow-up. Identical uncoated hemispherical acetabular implants were used in both groups. At the time of follow-up, at a mean of 2.2 years (range, two to 3.4 years) after the operation, the mean Charnley scores for pain, function, and motion were 5.6, 5.5, and 5.6 points, respectively, in the group that had received a hydroxyapatite-coated femoral component and 5.6, 5.6, and 5.6 points, respectively, in the group that had received a non-coated component; none of these differences were significant (p = 0.86, 0.89,, and 0.80, respectively). There were no revisions in either group. Radiographs indicated stable fixation in both groups and no differences in the radiographic parameters of loosening between the two groups. Within the relatively short time-frame of this study, there appeared to be no clinical or radiographic advantage to the use of hydroxyapatite in primary total hip arthroplasties. However, these results should be considered as preliminary. Longer follow-up may reveal unrecognized advantages or disadvantages.

Adult↗

Comparative risk of early postoperative pulmonary embolism after cemented total knee versus total hip arthroplasty with low-dose warfarin prophylaxis.

Four hundred thirteen cemented total hip arthroplasties and 852 cemented total knee arthroplasties were evaluated prospectively for postoperative pulmonary embolism. Inclusion criteria were a diagnosis of osteoarthritis, age 50 to 75 years old, cemented primary arthroplasty, and prophylaxis with low-dose warfarin (Coumadin, DuPont Pharma, Wilmington, Delaware). All patients underwent a preoperative perfusion scan and postoperative ventilation perfusion scan with all moderate probability scans evaluated with arteriogram. The overall incidence of pulmonary embolism was 3.8% after cemented total hip arthroplasty and 5.6% after cemented total knee arthroplasty. Because of a weight bias, patient age, weight, and gender-matched comparison was performed. Two hundred eighty-two patients from each group were matched with identical age, weight, and gender. The incidence of postoperative pulmonary embolism was 4.3% for total hip arthroplasty and 4.6% for total knee arthroplasty. These results do not support the contention that pulmonary embolism is higher after total hip arthroplasty than after total knee arthroplasty.

Aged↗

Primary cementless hip arthroplasty with a titanium plasma sprayed prosthesis.

One hundred two patients underwent 105 primary uncemented total hip arthroplasties and were reviewed at a minimum of 5 years after operation (mean, 6.1 years). The components were titanium alloy with a titanium plasma spray coating. The acetabular revision rate was 11.4%. Acetabular cavitary lytic lesions were identified in 25.5% at 5 years. All acetabular revisions were performed for a combination of wear and osteolysis. One femoral revision was performed to facilitate an acetabular revision, but the femoral revision rate for aseptic loosening was 0%. In addition, no femoral components had subsided or were thought to be loose radiographically. Thigh pain was present in 4% at 5 years. Despite the 25.5% incidence of acetabular osteolysis, distal femoral lysis was not seen and only 5% showed focal osteolysis in the trochanteric region proximal to the circumferential porous coating of the femoral component. Component design features were thought to be critical to the excellent performance of the femoral component and to the poor performance of the acetabular component.

Adult↗

Predicting quality-of-life outcomes following total joint arthroplasty. Limitations of the SF-36 Health Status Questionnaire.

A group of 114 patients undergoing total hip and knee arthroplasty were evaluated to assess the effect of total joint arthroplasty on quality of life, as measured by the SF-36 Health Status Questionnaire, and to determine the predictive relationship between preoperative and postoperative scores. A highly significant improvement was seen comparing preoperative with postoperative scores at 2 years for physical function, social function, physical role function, emotional role function, mental health, energy, and pain. Despite a significant change in health status (P < or = .001), no change was seen in the patient's health perception (P = .61). Regression analysis failed to indicate a predictive relationship between preoperative and postoperative scores for any scale. Total joint arthroplasty dramatically improves the quality of life and function of patients afflicted with arthritis; however, because of the poor ability of the SF-36 to predict postoperative improvement on an individual basis, it cannot be used alone to determine treatment selection.

Activities of Daily Living↗

Postoperative blood salvage in total knee arthroplasty using the Solcotrans autotransfusion system.

One hundred forty-four patients who underwent primary total knee arthroplasty were examined in a prospective controlled study to determine the efficacy and safety of a postoperative wound drainage autotransfusion system (Solcotrans, Smith & Nephew Richards, Memphis, TN). The patients were divided into two groups: control group 1 comprised 88 (61%) patients who either received a Hemovac disposable drainage system (63 patients) or the Solcotrans system and had inadequate drainage for autotransfusion (25 patients). Experimental group 2 comprised 56 (39%) patients who received a Solcotrans drainage system and were autotransfused. The Solcotrans proved itself safe. No sepsis, transfusion reactions, or coagulopathies were associated with autotransfusion, which averaged 524 mL. There were no significant differences between groups 1 and 2 when comparing preoperative and postoperative hemoglobins and hematocrits. The Solcotrans system did not lower homologous blood requirements. Only 1.6% (2 patients) of all patients who autodonated at least 2 units of autologous blood (122 patients) were in need of a homologous blood transfusion in the postoperative period. Thus, although safe, the Solcotrans system was not proven effective in the management of primary total knee arthroplasty patients.

Blood Transfusion, Autologous↗

Prospective randomized evaluation of blood salvage techniques for primary total hip arthroplasty.

A controlled, randomized, prospective study was performed evaluating the need for perioperative blood salvage for primary total hip arthroplasty patients who had donated autologous blood before surgery. One hundred fifty-three patients able to donate at least 2 units of autologous blood were divided into four groups. In group 1 (35 patients), intraoperative and postoperative Cell-Saver (Haemonetics, Braintree, MA) was employed. In group 2 (40 patients), a postoperative Solcotrans (Smith & Nephew Richards, Memphis, TN) reinfusion protocol was followed. In group 3 (40 patients), a closed-suction Hemovac drain (Zimmer, Warsaw, IN) was placed. In group 4, (38 patients), no drain was used. Decisions for transfusion were based on clinical and laboratory parameters and made in conjunction with medical consultation. All autologous blood was routinely reinfused. There was no statistically significant difference in transfusion requirements or wound complications among the four groups. Hemoglobin and hematocrit changes between groups also were not statistically significant, but a power test suggested insufficient patient numbers for absolute reliability of this observation. Only five patients (3.3%) in this study received homologous blood. Four of these patients were in the Solcotrans group and one was in the Cell-Saver group. Two reoperations were performed: one for hematoma (Solcotrans group) and one for a sewn-in drain. It is concluded that expensive perioperative blood salvage techniques are usually not needed in patients who have a primary total hip arthroplasty without cement and who have donated 2 units of blood before operation.

Adult↗

Comparison of cemented and cementless total hip arthroplasty in patients with bilateral hip arthroplasties.

A consecutive series of 36 patients underwent primary cemented total hip arthroplasty followed by primary cementless total hip arthroplasty of the contralateral hip. Clinical pain scores between the cementless and cemented hips were not different. Subjectively, patients either had no preference or preferred the cementless side. Comparison of results in the same patient eliminates variability introduced by differences in sex, weight, comorbidities, bone quality, and activity level. Control of these factors permits more meaningful comparison of the type of fixation.

Adult↗

Continuous passive motion after total knee arthroplasty. Analysis of cost and benefits.

The authors report the results of a prospective study examining the benefits of daily continuous passive motion combined with physical therapy, compared with physical therapy alone, in 103 consecutive osteoarthritic patients undergoing primary total knee arthroplasty. The first 51 patients received continuous passive motion initiated in the recovery room and the next 52 patients did not receive continuous passive motion. Both groups underwent an identical physical therapy protocol starting on the first postoperative day. At discharge, there was a significant increase in active flexion in the continuous passive motion group. There were no significant differences regarding pain, wound healing, knee swelling, wound drainage, pulmonary embolism, or length of hospital stay between the 2 groups. At 2 years, there were no clinical differences in the motion or knee scores. Knee manipulation was done for < 50 degrees flexion after the tenth postoperative day. There were 5 manipulations in the noncontinuous passive motion group and none in the continuous passive motion group. The entire costs associated with the 5 manipulations was $48,274 or $937 per patient not receiving continuous passive motion. The average daily inpatient rental of the machine was $60 per day. Continuous passive motion is efficacious in increasing short-term flexion and decreasing the need for knee manipulation without increasing costs.

Aged↗

Recementing a femoral component into a stable cement mantle using ultrasonic tools.

Recementing a femoral prosthesis into a retained cement mantle was done during revision total hip arthroplasty in 15 patients using ultrasonic tools to reshape the existing cement mantle. Early complications such as bone perforation or fracture were avoided. The 2-year followup in 4 patients revealed no adverse effect on the bone-cement interface as judged radiographically. One patient had rerevision for instability at 1 year after operation. Indications for this technique include isolated failure of the cement-prosthesis interface, femoral component fracture, or isolated acetabular revision in which exposure needs, instability, leg length inequality, or femoral-head size dictated change of the femoral component.

Acetabulum↗