Biomedical subjects

P M Faris

Publications and source records attributed to P M Faris.

At least 19 recordsLinked to original sources

PubMed1999

A comparison of collared and collarless femoral components in primary cemented total hip arthroplasty: a randomized clinical trial.

Between July 1986 and November 1989, 437 consecutive primary cemented total hip arthroplasties were performed using a straight-stemmed titanium alloy femoral component. Collared and collarless versions of this identical stem were randomly chosen by computer allowing a comparison between 213 collared stems (198 patients) and 224 collarless stems (209 patients). Diagnosis, sex, weight, and average age (72.8 years, collared; 72.0 years, collarless) were similar. Follow-up averaged 76 months (collared) and 72 months (collarless) with 49 patients followed for at least 10 years. Calcar-collar contact was noted in 205 hips (96%) on the initial postoperative radiograph. Early complications, including dislocations (5% each group), were similar. Late complications included 3 deep infections (2 collared, 1 collarless) and 2 postoperative femur fractures (1 each). Hip scores at the most recent follow-up averaged 91.2 and 90.1 in the collared and collarless groups. No or slight pain was noted in 93% of collared and 91.5% of collarless hips. Although no radiographic differences were noted in distal cortical hypertrophy, stem subsidence, and osteolysis, collarless hips lost significantly more medial femoral neck cortical bone (average 0.90 mm vs 0.63 mm). A higher incidence of radiolucent lines in femoral zone VI (20.7% vs 9.4%) was also noted in collarless hips.

Aged↗

PubMed1999

Comparison of the midvastus muscle-splitting approach with the median parapatellar approach in total knee arthroplasty.

A total of 100 patients having bilateral total knee replacements simultaneously were randomized prospectively--one knee having a vastus muscle-splitting approach and the other knee having a median parapatellar approach-to evaluate differences in lateral release, postoperative rehabilitation, ease of approach, and complications in total knee replacement surgery. There were 25 lateral releases on the muscle-splitting side and 26 on the median parapatellar side (P = .871). There were no differences in range of motion on day 2 or discharge, straight-leg raise, terminal knee extension, extensor lag, lateral release, or rehabilitation. There were 2 postoperative hematomas and 1 manipulation, all on the muscle-splitting side. All complications occurred from the muscle-splitting side. The muscle-splitting approach cannot be recommended as being superior to the median parapatellar approach.

Adult↗

PubMed1999

The clinical significance of proximal tibial resection level in total knee arthroplasty.

Clinical and radiographic data were collected in 139 patients with 195 posterior cruciate retaining total condylar knee prostheses to evaluate the relationship of the proximal tibial resection level with long term results. Among the 139 patients were 75 patients with 106 total knee replacements observed for more than 8 years. All patients underwent biyearly routine examinations, including radiographs and clinical evaluations. The average medial tibial resection for the 139 patients with 195 total knee replacements was 2.95 mm, and in the subset of 75 patients (106 knees) observed for more than 8 years, it was 3.3 mm; both groups had a maximum of 14 mm. Sixty-three percent or 67 knees had medial resection levels of 3 mm or less. The average lateral tibial resection for the 195 knees was 5.48 mm and in the 106 knees was 5.71 mm, with a maximum of 22 mm. Fifty-one percent of 104 knees had lateral resection levels of 5 mm or less. Statistical analysis showed that there was no significant correlation between the level of proximal tibial resection and Knee Society knee score, range of motion, radiolucencies, or loosening or revision. These long term results suggest that minimal proximal tibial resection is not necessary for a successful arthroplasty, and problems associated with minimal resection, such as joint line elevation and thin polyethylene inserts, can be avoided.

Adult↗

PubMed1999

Intra-articular morphine and/or bupivacaine after total knee replacement.

The postoperative analgesic effects of intra-articular injections of bupivacaine and/or morphine were examined prospectively in 437 patients who had total knee replacement for osteoarthritis. They were divided randomly into four groups. Group I received 10 mg of morphine (1 ml) and 9 ml of saline, group II received 10 ml of bupivacaine (2.5 mg/ml), group III received 10 ml of saline, and group IV received 10 mg of morphine (1 ml) and 9 ml of bupivacaine (2.5 mg/ml). All analgesics administered in the first 24 hours after operation were recorded. The patients rated their pain on the McGill-Melzack scale at 1, 6, 12 and 24 hours. No significant differences were found between any of the groups in the use of Demoral and/or Toradol in 24 hours, the length of stay in hospital or the pain rating at 1, 6, 12 or 24 hours. Patients in groups I and IV, whose injections included morphine, used significantly more morphine in the first 24 postoperative hours than did groups II or III.

Adult↗

PubMed1999

The predictive power of baseline hemoglobin for transfusion risk in surgery patients.

Preoperative hemoglobin concentration may be an important predictor of transfusion risk in surgical procedures with significant expected blood loss. Contemporary studies investigating transfusion risk with regard to the relationship between perioperative administration of Epoetin alfa and baseline hemoglobin provide data to test this hypothesis. The predictive power of seven preoperative variables (hemoglobin concentration, age, erythropoietin level, ferritin concentration, serum iron, total iron-binding capacity, and predicted blood volume) on transfusion risk was examined via retrospective logistic regression analysis of 276 orthopedic surgical patients. In the two studies used to perform the regression analysis, patients were treated daily with either Epoetin alfa or placebo. Based on the retrospective analyses, a prospective study was conducted to validate the hypothesis. Of the seven variables evaluated, baseline hemoglobin concentration and predicted blood volume were significantly predictive of transfusion risk in both Epoetin alfa- and placebo-treated patients. Further, an inverse correlation between hemoglobin concentration and transfusion risk was demonstrated in placebo-treated patients. Placebo-treated patients with hemoglobin > 10 to < or = 13 g/dL had an approximately twofold greater risk of transfusion than patients with hemoglobin > 13 g/dL. In contrast to placebo treatment, Epoetin alfa significantly reduced transfusion risk in patients with hemoglobin > 10 to < or = 13 g/dL. Baseline hemoglobin concentration is an excellent predictor of transfusion risk in orthopedic surgical patients. As a result, hemoglobin testing should be considered a part of routine preoperative testing for orthopedic surgical patients.

Arthroplasty, Replacement, Hip↗

PubMed1999

Patellar complications (total knee arthroplasty). Effect of lateral release and thickness.

One thousand, one hundred forty-six Anatomic Graduated Component total knee arthroplasties performed between 1987 and 1989 were used to investigate the effects of patellar thickness alone or coupled with lateral retinacular release on initial patellar complications and maximal flexion. Lateral release was found not to be statistically significant regarding radiolucency, patellar prosthesis loosening, or an increase or decrease in flexion. However, total knee arthroplasties in which a lateral release was done, which either saved the superior lateral genicular artery or sacrificed the superior lateral genicular artery, were found to increase the incidence of initial patellar fractures and/or loosening (complications within 1 year) when compared with total knee arthroplasties in which a lateral release was not performed. There was no statistical difference in failure rates regarding fractures and/or loosening of the patella between lateral releases in which the superior lateral genicular artery was saved and the lateral releases in which the superior lateral genicular artery was sacrificed. A difference in postoperative patellar thickness compared with preoperative patellar thickness was found not to be significant to initial patellar fracture and/or loosening, patellar fracture alone, patellar loosening alone, radiolucency, the need for a lateral release, or to an increase or decrease in flexion. Lateral release and patellar thickness had no significant effect on patellar fracture and/or loosening.

Adult↗

PubMed1998

Life expectancy after total hip arthroplasty.

A total of 3,807 patients undergoing total hip arthroplasty (THA) between the years 1970 to 1995 were evaluated for mortality. Patient age groups were designated in 10-year intervals as follows: age <40; 41-50; 51-60; 61-70; 71-80; age >80. The life expectancy estimate of the patients with THA was calculated by the Kaplan-Meier method, and that of the normal population was obtained from standard life-tables. Statistical significance was evaluated using 95% confidence limits. A significant difference in life expectancy was found in patient age groups >60 (61-70, 71-80, >80) demonstrating significantly higher survival rates among THA patients when compared with the normal population.

Adult↗

PubMed1998

Predictors of transfusion risk in elective knee surgery.

Two hundred seventy-nine patients undergoing primary unilateral total knee replacement and 280 patients undergoing primary bilateral total knee replacements were reviewed retrospectively. Patients' height, weight, hemoglobin level before donation, hemoglobin level before surgery, autologous donation, number and type of transfusions whether autologous or allogeneic, and hemoglobin at discharge were collected from hospital and clinic records. The average drop in hemoglobin was 3.85 g/dL in the group of patients undergoing unilateral total knee replacement and 5.42 g/dL in the group of patients undergoing bilateral total knee replacements. The preoperative hemoglobin and blood volume seemed to be very strong, statistically significant predictors of transfusion risk in single and bilateral knee replacements. In unilateral total knee replacement, patients with a hemoglobin of greater than 13 g/dL had only an 8% chance of transfusion and if they donated autologous blood, 66% of the blood was wasted. Preoperative anemia was a strong predictor of transfusion risk in patients undergoing unilateral and bilateral total knee replacements and carried a very high allogeneic transfusion exposure risk, even in patients who had donated blood preoperatively. A nomogram was developed using blood volume and predonation hemoglobin to predict transfusion risk and need to predeposit autologous blood in patients undergoing unilateral and bilateral total knee replacements.

Aged↗

PubMed1998

Maximizing cost-effectiveness while minimizing complications in total hip replacement.

Between July 1989 and June 1994, a consecutive series of 651 cemented total hip arthroplasties were performed in 577 patients using relatively inexpensive implants and standardized surgical and postoperative protocols. We set out to determine what effect these cost-saving measures have on the overall success and complication rate after total hip replacement surgery. Surgical results remained excellent, and perioperative, early, and late complications, including infection, loosening, and revision hip surgery, remained minimal, indeed, below usual complication rates. We concluded that cost-effective measures can be implemented while maintaining the overall excellent results of hip replacement surgery without the risk of increasing complication rates.

Adult↗

PubMed1998

Epoetin alfa. A bloodless approach for the treatment of perioperative anemia.

Under normal physiologic conditions the level of circulating red blood cells is regulated precisely by the glycoprotein erythropoietin. In major elective surgery, patients who are participating in preoperative autologous blood donation or who are anemic may not have the capacity to manufacture sufficient red blood cells in response to increases in endogenous erythropoietin that is sufficient to avoid perioperative allogeneic blood transfusion. In these patients pharmacologic doses of recombinant human erythropoietin (Epoetin alfa) have been shown to accelerate erythropoiesis, thereby increasing preoperative red blood cell production, hematocrit level, and hemoglobin concentration and reducing exposure to allogeneic blood transfusion. In four large multicenter studies, 869 patients undergoing major elective surgery were treated with a daily regimen (300 or 100 IU/kg x 14 or 15 doses) or a weekly regimen (600 IU/kg x 4 doses) of subcutaneous Epoetin alfa beginning either 2 or 3 weeks before surgery, respectively. Although all Epoetin alfa regimens were effective at accelerating erythropoiesis and increasing red blood cell production, the weekly regimen was the most patient friendly, cost effective regimen for treating preoperative anemia and minimizing patient risk of allogeneic blood transfusion.

Anemia↗

PubMed1997

Comparison of collared and collarless femoral components in primary uncemented total hip arthroplasty.

Two hundred three consecutive primary uncemented total hip arthroplasties were prospectively randomized using collared and collarless versions of an identical titanium stem. Identical 28-mm titanium heads were implanted in all cases. One hundred three collared hips were compared with 100 collarless hips. Follow-up periods averaged 45.7 months in both groups. Intraoperative, early, and late complications were similar. Hip scores, including thigh pain, at final follow-up visit were also similar. No significant differences were noted in acetabular or femoral radiolucencies, subsidence, osteolysis, or proximal femoral remodeling. At 5 years, more collarless stems revealed pedestal formation (57.1% vs 33.9%). The presence of a collar had no effect on the adequacy of fixation, proximal femoral osteopenia, or clinical scores at 5 years.

Adult↗

PubMed1997

Total hip arthroplasty in patients with osteonecrosis. The effect of cement techniques.

One hundred fifteen patients who underwent total hip replacement for osteonecrosis between June 1972 and April 1990 were divided into 3 groups according to the cause of the disorder: (1) osteonecrosis secondary to alcoholism (21 patients), (2) osteonecrosis secondary to hypersteroidism (29 patients), and (3) idiopathic osteonecrosis (65 patients). To determine the differences in short and long term arthroplasty failure rates, these 3 patient groups were compared with a group of 202 patients who received total hip replacement for osteoarthritis. Statistical analyses were carried out on the following definitions of failure: loosening of the acetabular component, loosening of the femoral component, and revision arthroplasty. Radiolucency and postoperative pain scores also were evaluated. A significant difference in the rate of failure because of loosening of the femoral component was found among the 4 groups. Likewise, a significant difference was found among the 4 groups in all revisions or loosenings or both. However, only the comparison between the idiopathic osteonecrosis and osteoarthritic groups showed a significant difference with survival analysis. Second generation cement technique was as significant as any variable relating to failure. The authors conclude that total hip arthroplasty is an equally viable treatment for the 3 types of osteonecrosis examined in this study; however, failure might be more imminent in studies where larger numbers are needed.

Aged↗

PubMed1997

Impaction bone-grafting before insertion of a femoral stem with cement in revision total hip arthroplasty. A minimum two-year follow-up study.

Impaction bone-grafting was performed before insertion of a collarless, polished, tapered femoral stem with cement in thirty-four revision total hip arthroplasties (thirty-four patients) that were done because of aseptic loosening. The average duration of follow-up was thirty months (range, twenty-four to forty-two months). The operation was the initial revision in twenty-eight patients (82 per cent). Twenty-two patients (65 per cent) also had revision of the acetabular component. Complications included four intraoperative and two postoperative fractures of the femur as well as one dislocation (at one month). Two patients (6 per cent) needed a repeat revision of the femoral stem because of aseptic loosening at twenty-six and thirty-six months postoperatively. Both of these patients had an associated fracture of the femur (one was intraoperative, and the other was postoperative). Subsidence was common (thirteen patients; 38 per cent) and averaged 10.1 millimeters (range, four to thirty-one millimeters). Although the study group was relatively small, with the numbers available subsidence was not found to be associated with the preoperative or postoperative hip score, segmental or cavitary femoral defects, femoral ectasia, intraoperative fracture of the femur, strut-grafting, trochanteric osteotomy, or varus position of the femoral component. Incorporation of the allograft into the trabecular bone and secondary remodeling were noted radiographically in thirty-two (94 per cent) and fourteen (41 per cent) of the patients, respectively, often within one year. Although the duration of follow-up was relatively short, no localized resorption of the allograft occurred and cortical repair was noted in one patient at three years. At the most recent follow-up evaluation, the Harris hip scores had improved from a preoperative average of 51 points (range, 32 to 90 points) to an average of 87 points (range, 65 to 100 points) and twenty-eight patients (82 per cent) had no or only slight pain. Despite the satisfactory early clinical results, we remain concerned about the high rate of fracture of the femur and the rate and extent of subsidence of the femoral component. On the basis of the worrisome findings after this two-year period, we recommend that impaction bone-grafting be used only when proximal femoral osteopenia is so severe that stability cannot be obtained with insertion of a long-stemmed femoral component without cement. In that setting, impaction bone-grafting may be considered instead of implantation of a massive proximal femoral allograft in combination with insertion of a femoral component with cement.

Adult↗

PubMed1997

Radiographic analysis of a cemented titanium alloy femoral component.

Proximal femoral cortical bone remodeling was evaluated radiographically about a 1 piece cemented titanium alloy femoral prosthesis implanted with modern cement techniques and was compared with one described previously in which early cement techniques and a stainless steel stem were used. Two hundred twenty-six total hip replacements (196 patients) were observed for an average of 6.3 years (range, 5-10 years). Analysis of all hips revealed that the ratio of cortical thickness to that of the overall femoral bone diameter did not change significantly about the periprosthetic bone throughout the length of the study. Cortical hypertrophy and atrophy occurred at rates similar to those seen with the early cement techniques. Distal fusiform cortical hypertrophy and the formation of osteosclerotic (reactive) lines at the bone cement interface occurred at approximately half the rate using modern cement techniques. In addition, cortical atrophy was associated with the formation of these reactive lines, the occurrence of osteolytic lesions, and progressive bone cement interface radiolucencies. Although periprosthetic cortical atrophy occurred at rates similar to those reported previously, important differences were noted between the findings of this study and the earlier study; these differences most likely were a result of cement technique or the prosthesis.

Aged↗

PubMed1996

Patellofemoral complications following total knee arthroplasty. Effect of a lateral release and sacrifice of the superior lateral geniculate artery.

Between 1987 and 1989, 1,205 Anatomic Graduated Component (AGC, Biomet, Warsaw, IN) total knee arthroplasties were performed by three surgeons using the same prosthesis and same technique. Four hundred twenty-eight total knee arthroplasties (35%) had lateral releases; in 107 (75%) of these, the superior lateral geniculate artery was saved. Lateral release had no effect on patellar subluxation, dislocation, or loosening, but was associated with significantly more patellar fractures. Conversely, patellar radiolucency was more common in knees without a lateral release. Furthermore, saving the superior lateral geniculate artery during a lateral release had no effect on patellar dislocation, radiolucency, loosening, or fracture.

Aged↗

PubMed1996

Outcome of the contralateral hip following total hip arthroplasty for osteoarthritis.

One thousand one hundred and sixteen patients who underwent unilateral total hip arthroplasty osteoarthritis between 1970 and 1980 were examined for development, progression, and total hip arthroplasty in the contralateral joint. At the time of the original surgery, 452 patients were diagnosed with bilateral osteoarthritis and 664 had a normal contralateral hip. The probability of osteoarthritis progressing in the contralateral joint is 78.6% at 10 years, with the chance of arthroplasty being 53.8%. The probability of a hip diagnosed as normal developing osteoarthritis is 36.5% at 10 years, with an 8.3% chance of requiring total hip arthroplasty.

Adult↗

PubMed1996

Tibial shaft fracture following tibial tubercle osteotomy.

Tibial tubercle osteotomy has been reported to be an excellent exposure for a very stiff primary or revision knee requiring total knee arthroplasty. In 1993, the Center for Hip and Knee Surgery performed 657 primary and 16 revision total knee arthroplasties, using tibial tubercle osteotomy in 9 cases, 2 of which sustained tibial shaft fractures, because of which the Center's experience is reviewed.

Aged↗

PubMed1996

The effects of recombinant human erythropoietin on perioperative transfusion requirements in patients having a major orthopaedic operation. The American Erythropoietin Study Group.

Two hundred patients who were scheduled for a major elective orthopaedic operation were enrolled in a prospective study and were randomly assigned to one of three treatment groups. Group 1 consisted of sixty patients who received recombinant human erythropoietin, 300 international units per kilogram of body weight per day; Group 2, seventy-one patients who received recombinant human erythropoietin, 100 international units per kilogram of body weight per day; and Group 3, sixty-nine patients who received a placebo. A total of fifteen doses was given subcutaneously, beginning ten days before the operation and extending through the fourth postoperative day. Patients who declined or were unable to donate autologous blood preoperatively were included in the study and were maintained on iron supplementation orally. The decision to transfuse red blood cells depended on the physician, however, physicians were encouraged not to do so if the hematocrit was more than 0.27 (27 per cent), unless the clinical symptoms warranted it. Of the 185 patients who were evaluable with regard to efficacy, significantly fewer patients received homologous red-blood-cell transfusions in Groups 1 and 2 (17 per cent [nine] and 25 per cent [sixteen], respectively) than in Group 3 (54 per cent [thirty-six]) (p < 0.001). When the patients were stratified into two groups on the basis of the pre-treatment hemoglobin level (more than 100 to 130 grams per liter or more than 130 grams per liter), we found that patients who had received a placebo and had a baseline hemoglobin level of more than 100 to 130 grams per liter were at significantly higher risk for transfusion (78 per cent [twenty-one]) than those who had received a placebo and had a baseline level of more than 130 grams per liter (36 per cent [fourteen]). For patients who had a baseline hemoglobin level of more than 100 to 130 grams per liter, the higher dose of recombinant human erythropoietin appeared somewhat more effective than the lower dose, with 14 per cent (three) of the patients in Group 1 and 39 per cent (nine) in Group 2 needing a transfusion; however, the difference was not significant (p = 0.09). For patients who had a baseline hemoglobin level of more than 130 grams per liter, the two doses of recombinant human erythropoietin produced similar results, with 14 per cent (four) of the patients in Group 1 and 11 per cent (four) in Group 2 needing a transfusion; this was in contrast to a rate of transfusion of 36 per cent (fourteen) in Group 3 (the patients who received the placebo) (p = 0.03). The recombinant human erythropoietin was generally well tolerated, although one patient, who did not have a history of hypertension, had an increase in blood pressure, from a baseline level of 142/78 millimeters of mercury (18.93/10.40 kilopascals) to a level of 220/100 millimeters of mercury (29.33/13.33 kilopascals), after ten days of treatment with the higher dose. These data suggest that recombinant human erythropoietin, administered before and after major orthopaedic operations, can minimize the need for homologous red-blood-cell transfusion.

Aged↗