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Clinically silent lesions on cerebral magnet resonance imaging have been found in larger numbers after pulmonary vein isolation (PVI) especially with phased radio frequency (pRF) using all ten electrodes. However, the neuropsychological effects of cerebral microembolism during the procedure remain unclear and data regarding this issue so far are inconsistent. Between August 2011 and June 2012, 76 patients undergoing their first PVI were randomized to ablation with either phased (40) or irrigated (36) radio frequency (iRF). A comprehensive neuropsychological test battery was performed the day before and after PVI as well as 6 months after ablation. The occurrence of cerebral microemboli during the procedure was performed via a transcranial Doppler ultrasound device. PVI using pRF was associated with increased number of microembolic signals (MES) compared to iRF (1530.0 ± 979.8 vs. 645.7 ± 448.7; p

Case Challenges in Hip & Knee Surgery

IDDM patients treated with conventional subcutaneous insulin have an abnormal increase in cholesteryl ester transfer (CET), the proatherogenic step in reverse-cholesterol transport that results in the enrichment of the apolipoprotein (apo) B-containing lipoproteins (VLDL, LDL) with cholesteryl ester (CE). This disturbance is closely linked to iatrogenic hyperinsulinemia and the nonphysiologic stimulation of lipoprotein lipase (LpL), a physiologic activator of CET, because lowering systemic insulin levels by administering insulin through the intraperitoneal insulin route normalizes LpL and CET. Hyperinsulinemia persists in IDDM patients who undergo successful pancreas-kidney transplantation (PKT) when their allografts are placed in the pelvis and drain into the iliac vein. Therefore, to determine whether hyperinsulinemia promotes CET in this setting, we studied CET, LpL, and insulin levels in 14 euglycemic normolipidemic IDDM PKT patients with nearnormal kidney function (creatinine 1.5 ± 0.4 mg/dl). Consistent with our prediction, the net mass of CE transferred from HDL to VLDL + LDL was significantly increased in the PKT group (P < 0.001) compared with nondiabetic renal transplant patients receiving the same immunosuppressive drugs and healthy control subjects. Both basal and arginine-stimulated insulin levels were increased above the kidney transplant group's levels and correlated with the mass of CE transferred at 2 h (r = 0.71, P < 0.05; r = 0.66, P < 0.05, respectively). Total basal LpL activities, LpL and hepatic triacylglycerol lipase activities, and LpL mass all tended to be higher than levels in healthy control subjects. Consistent with these changes in lipase activity, VLDL particle size was significantly reduced (P < 0.025) compared with that of control subjects. These findings indicate that PKT patients with systemically draining allografts have a persisting profile of potentially atherogenic disturbances in insulin levels, LpL, and CET that resemble IDDM patients treated with conventional subcutaneous insulin injections.

To characterize further the impact of thyroid dysfunction on the transport of cholesterol in plasma, we studied plasma lipids and cholesteryl ester transfer (CET) in 10 hypothyroid women before and 3 months after thyroid replacement therapy. CET, estimated as the net mass transfer of CE from HDL to the apolipoprotein B-containing lipoproteins (very low density and low density lipoproteins) was significantly decreased at 4 h (P < 0.05) and 6 h (P < 0.001) when the patients were hypothyroid (T4, 2.01 +/- 1.4; TSH, 55.5 +/- 39.9 microIU/mL) and increased to normal levels after hormone replacement and restoration of eumetabolism. Plasma lipid levels in the hypothyroid state closely resembled those in a female reference group, although total plasma cholesterol fell significantly [pretreatment, 218 +/- 36 vs. posttreatment, 192 +/- 49 (P < 0.025); control, 218 +/- 28 mg/dL (mean +/- SD)] after treatment. Concentrations of cholesteryl ester transfer protein (CETP) were unchanged (pretreatment, 2.35 +/- 0.83 vs. posttreatment, 2.30 +/- 1.19 mg/dL). The results of recombination studies using different lipoprotein fractions suggest that decreases in CET during hypothyroidism may be secondary to acceptor lipoprotein (low density and very low density lipoprotein) changes in the hypothyroid state and not to changes in the concentration of CETP itself.

Silent brain infarctions are frequently found by modern cerebral imaging. Up to 30% of persons without a clinical history of stroke were found to have silent brain infarction in epidemiological studies. "Silent" refers to ischemic brain lesions for which no matching clinical syndrome can be found based on history or clinical investigation. Age, education, and ethnic background have a strong impact on noticing and reporting stroke symptoms. The current clinical definition of stroke is insensitive for cognitive deficits which can also be caused by brain infarctions. The majority of silent brain infarctions are localized in the subcortical white matter of the brain; however, about 10% of silent brain infarctions are cortical. Silent brain infarctions are strongly associated with stroke risk factors and comorbidities that are known to cause clinically overt stroke. Silent brain infarctions are 5 to 10 times more frequent than clinically overt strokes. Silent brain infarctions as defined by DWI lesions on MRI imaging are a frequent finding during operative or interventional procedures and their monitoring may help improve the respective techniques in order to decrease the risk of periprocedural stroke.

The long-term success of total knee replacement is multifactorial, including factors relating to the patient, the operation and the implant. The purpose of this study was to examine the 20-year survival of the cemented Anatomical Graduated Component (AGC) total knee replacement. Between 1983 and 2004, 7760 of these were carried out at our institution. Of these, 6726 knees which received the non-modular metal-backed tibial component with compression-moulded polyethylene and had a minimum two-year follow-up were available for study. In all, 36 knees were followed over 20 years with a survival of the tibial and femoral components together of 97.8% (95% confidence interval (CI) 0.9851 to 0.9677), with no implants being revised for polyethylene wear or osteolysis. Age > 70 was associated with increased survival (99.6%, 95% CI 99.0 to 99.8) (p < 0.0001) but pre-operative valgus alignment reduced survival (95.1%, 95% CI 90.0 to 97.6) (p = 0.0056). Age < 55 (p = 0.129), pre-operative varus alignment (p = 0.707), osteonecrosis (p = 0.06), rheumatoid arthritis (p = 0.247), and gender (p = 0.666) were not statistically associated with failure. We attribute the success of the AGC implant to its relatively unconstrained articular geometry and the durability of a non-modular metal-backed tibial component with compression moulded polyethylene.

Epidemiologic studies and in vitro experiments indicate that low density lipoprotein (LDL) subtypes differ concerning their atherogenic potential. Small, dense LDL are more atherogenic than large, buoyant LDL. LDL apheresis is a potent therapeutic modality to lower elevated LDL-cholesterol. It is unknown whether such therapy induces a shift in the LDL subtype distribution. In this study we evaluated the influence of LDL apheresis on the LDL subtype distribution in patients with CHD and familial hypercholesterolemia (FH, n = 22), combined hyperlipidemia (CHLP, n = 6), or Lp[a]-hyperlipoproteinemia (Lp[a]-HLP, n = 4) regularly treated by LDL apheresis (immunoadsorption (n = 14), HELP apheresis (n = 8), dextran sulfate adsorption (n = 7), cascade filtration (n = 3)). On the basis of 6 LDL subfractions (d 1.020;-1.057 g/mL) isolated by density gradient ultracentrifugation the LDL-density profile was determined in each patient before and after apheresis. There was a relative increase of LDL-subfractions 1, 2, and 3 (P0.01, P0. 05, and P0.01, respectively) and a concomitant decrease of LDL subfractions 5 and 6 (P0.05) after apheresis. Subgroup analysis indicates that the degree of the small, dense LDL reduction was much more prominent in patients with CHLP compared to patients with FH or Lp[a]-HLP, whereas the type of apheresis technique had no effect. The extent of small, dense LDL reduction correlated with the preapheresis concentrations of small, dense LDL and triglycerides but not with the extent of triglyceride reduction.We conclude that LDL apheresis not only decreases LDL mass, but also improves LDL-density profile, particularly in patients with CHLP.

Berthold HK, Parhofer KG, Ritter MM, Addo M, Wasmuth JC, Schliefer K, Spengler U, Rockstroh JK (University of Bonn and University of Munich, Germany). Influence of protease inhibitor therapy on lipoprotein metabolism. J Intern Med 1999; 246: 567–575. Objectives. Protease inhibitors are efficient drugs as part of highly active antiretroviral therapy. They have been shown to cause hyper- and dyslipoproteinemia. Since antiretroviral therapy is able to delay disease progression and possibly extend life expectancy in HIV-infected individuals, the precise nature of serum lipid disturbances may become of clinical interest with respect to its atherogenicity and to finding treatment options. Design. We investigated prospectively, in 19 subsequent HIV-positive male patients (mean age 42 ± 13 years), multiple lipid parameters in plasma, before and during treatment with a protease inhibitor (nelfinavir, ritonavir, or indinavir) and two nucleoside analogue reverse transcriptase inhibitors (NRTI). The median (range) treatment duration was 22 (7–40) weeks. 12 patients were treatment-naive; 7 had already NRTI medication at baseline. Results. Total cholesterol increased by 28 mg dL–1 (95% CI: + 7 to + 48, baseline 158 ± 53, P = 0.01), triglycerides increased by 96 mg dL–1 (+ 22 to + 170, baseline 152 ± 91, P = 0.014), HDL cholesterol was unchanged, LDL cholesterol was slightly but not significantly elevated, VLDL cholesterol increased by 20 mg dL–1 (+ 9 to + 31, baseline 33 ± 21, P = 0.001), VLDL triglycerides increased by 86 mg dL–1 (+ 22 to + 150, baseline 128 ± 91, P = 0.01). The ratio of total cholesterol to HDL cholesterol increased by 1.2 (+ 0.7 to + 1.7, baseline 4.8 ± 1.5, P = 0.0001) and the ratio of HDL2 to HDL3 decreased by 0.06 (–0.02 to –0.09, baseline 0.47 ± 0.11, P = 0.005). (Conversion factors, mg dL–1 to mmol L–1: 0.0259 for cholesterol, 0.0114 for triglycerides.) Conclusions. The data indicate that the predominant feature of dyslipidemia under protease inhibitors is an increase in triglyceride-containing lipoproteins. This observation is in accordance with the hypothesis of increased apoptosis of peripheral adipocytes, release of free fatty acids and subsequent increased synthesis of VLDL. The lipid profile, based on the ratio of total cholesterol to HDL cholesterol and the ratio HDL2 to HDL3, is significantly more atherogenic.

We have made a retrospective review of 185 cemented Charnley total hip arthroplasties performed between 1970 and 1974 to determine the relationships between radiological variables and failure of the femoral and acetabular components. We measured the acetabular wear, the orientation of the cup, the thickness and consistency of acetabular and femoral cement mantles, radiolucency and femoral alignment. The mean follow-up was for 11.7 years. Femoral loosening was demonstrable radiologically in 15 hips (8.1%), ten (5.4%) of which were revised during the period of follow-up. Only when the first postoperative radiograph showed a thin cement mantle in Gruen zone 5 was there a significant association with failure of the femoral component. There were 12 loose acetabular components (6.5%), nine (4.8%) of which were revised. When the initial radiograph after operation showed radiolucency in DeLee and Charnley zone 1, the incidence of acetabular loosening was 28.21%. If such radiolucency was not present, the incidence of acetabular loosening was only 0.69%. Our findings emphasise the importance of careful cementing.

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.

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.

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.

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.

One hundred and eighty-one families with multiple endocrine neoplasia type 2A (MEN-2A) or familial medullary thyroid carcinoma (FMTC) have been investigated for mutations in the ret protooncogene in Germany. In 8 families with FMTC or MEN-2A, no mutation could be detected in the cysteine-rich domain encoded in exons 10 and 11 of the ret protooncogene. DNA sequencing of additional exons (no. 13-15) revealed rare noncysteine mutations in 3 families (codons 631, 768, and 844). In contrast to these rare events, heterozygous missense mutations in exon 13, codons 790 and 791, were found in 5 families (4 with MTC only; 1 family with MTC and pheochromocytoma) and 11 patients with apparently sporadic tumors. Two different mutations in codon 790 (TTG--TTT, TTG--TTC; Leu790Phe) and one mutation in codon 791 (TAT--TTT; Tyr791Phe) created a phenylalanine residue. We conclude that codons 790 and 791 of the ret protooncogene represent a new hot spot for FMTC/MEN-2A causing mutations. With the discovery of these considerably common mutations in codons 790 and 791 and the identification of some rare mutations, 100% of the German FMTC/MEN-2A families could be characterized by a mutation in the ret protooncogene.

Pheochromocytoma is a tumor that may occur sporadically or may be a manifestation of a hereditary disease, such as von Hippel-Lindau disease (VHL) and multiple endocrine neoplasia (MEN) type 2. As patients with VHL or MEN type 2 are at risk to develop multiple tumors, they must be distinguished from sporadic cases. We determined the incidence of VHL and MEN type 2 among 62 German patients diagnosed with pheochromocytoma without a history of a hereditary disease. Germline analyses of the vhl gene and exons 10, 11, and 13 of the ret protooncogene were performed by PCR, single strand conformation polymorphism, enzyme digestion, or sequencing. Two patients (3%) showed vhl mutations (95% confidence interval, 1-11%). One patient showed loss of the MspI restriction site at nucleotides 712/713. Another patient had a C/T change at an intronic site that was also detected in 2 of his offspring. No mutations were detected in the ret protooncogene (97.5% confidence interval, 0-6%). In Germany, most sporadic pheochromocytomas are not due to VHL or MEN type 2. Therefore, clinical work-up in patients with pheochromocytoma without signs of hereditary disease is not recommended. However, because the costs of genetic screening are relatively low, and each index case allows optimal care for family members, molecular testing might be cost-effective.

The aim of this study was to evaluate the accuracy of symptomatology and esophagogastroduodenoscopy (EGD) in the diagnosis of proven gastroesophageal reflux disease (GERD). We evaluated the symptoms and EGD findings of 100 consecutive patients presenting with symptoms suggestive of GERD. Patients' symptoms were scored at their first visit with a standardized symptom scoring system (grades 0-3). Grade 3 symptoms were the most severe. EGD findings were classified according to the modified Savary-Miller scale. Esophageal acid exposure was quantified using 24-hour esophageal pH monitoring; a positive composite score was considered evidence of GERD. Fifty-seven patients had positive pH scores, and 43 were negative. The combination of grade 2 or 3 heartburn and/or regurgitation with erosive esophagitis or Barrett's esophagus on EGD had a 97 per cent specificity and 64 per cent sensitivity for accurately diagnosing GERD. It is concluded that, in the presence of moderate to severe symptoms and endoscopic injury, the diagnosis of GERD can be made without further studies. However, 24-hour esophageal pH monitoring is still indicated in patients with mild typical symptoms, atypical symptoms, or when the combination of heartburn and regurgitation, regardless of their severity, occurs in the absence of severe mucosal damage.

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.

The net mass transfer of cholesteryl ester (CE) from high density lipoprotein (HDL) to the apolipoprotein (apo) B-containing lipoproteins, very low density lipoprotein (VLDL) and low density lipoprotein (LDL) in plasma (cholesteryl ester transfer (CET)) from three patients lacking lipoprotein lipase (LpL) activity was significantly lower (P0.001) than in plasma from fasting control subjects with comparable triglyceride levels. Chylomicrons isolated from LpL-deficient fasting plasma showed the same low level of CET activity as observed in the intact plasma when combined with HDL and cholesteryl ester transfer protein (CETP)-containing d 1.063 g/ml bottom fractions from control subjects. Preincubation of chylomicrons and large triglyceride-rich lipoproteins (Sf400) from LpL-deficient plasma with milk LpL, however, stimulated the capacity to engage in CET 4- to 5-fold to the same level as chylomicrons and VLDL from control subjects after a fat load. Consistent with these measurements of CET activity in plasma, chylomicrons obtained from the LpL-deficient subjects after a 14-h fast had higher TG/CE ratios than chylomicrons from controls 3 h after ingesting a fat load (LpL-deficient 26.3 +/- 9.0 vs. controls 6.9 +/- 2.1; mean +/- SD). The mass of CETP did not differ in LpL-deficient and control subjects (LpL-deficient 1.03 +/- 0.22 micrograms/ml vs. controls 1.58 +/- 0.58 micrograms/ml). These studies are consistent with earlier in vitro studies showing that the actions of lipoprotein lipase and its lipolytic products are essential, for maximal cholesteryl ester transfer protein activity.

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]) (p0.001). 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.

Flat-on-flat, posterior cruciate ligament-sparing total knee prostheses recently have shown problems of wear, loosening, and multiple design changes. Two thousand one Anatomical Graduated Components total knee arthroplasties with compression molded, nonmodular polyethylene tibial components were done between 1983 and 1991 at 3 institutions. All knees were evaluated clinically and radiographically every 2 to 3 years; 71 knees were seen in followup10 years. There were 8 failures secondary to revision (5 tibial failures; 2 secondary to metalosis from patellar polyethylene dissociation; and 3 femoral failures) resulting in a 98% survival rate at 10 years. The tibial design was flat-on-flat with a compression molded polyethylene that the authors believe is the primary reason for its success.

Polyethylene wear debris has been identified as a cause of osteolysis, granuloma formation, and loosening in total hip arthroplasty. This study was designed to evaluate differences in polyethylene wear rates between acetabular cups machined from extruded bar stock and those direct compression molded. Two hundred thirty-six hip prostheses underwent radiographic evaluation using the technique of Livermore et al. Seventy-four were all-polyethylene cups machined from extruded bar stock, and 162 were all-polyethylene cups direct compression molded. Both groups were similar in that the acetabular and femoral components were all cemented, the acetabular components were all polyethylene, nonmetal backed, and bearing surfaces of both groups were polished, cobalt chrome. The femoral components were TRIAD in the machined group and TR28 in the molded group. Patient matching was performed, assigning 54 patients in each group, whose average age was 66 years old, average followup 6.7 years, and average weight 161 pounds. Rates of polyethylene wear then were compared. Results showed a linear wear rate of 0.05 mm per year for compression-molded polyethylene and 0.11 mm per year for machined polyethylene. Results of this study raise questions regarding the types of polyethylene fabrication and its ultimate molecular weight, and wear resistance.

Polyethylene wear increasingly has been blamed for osteolysis and granuloma formation after total joint arthroplasty. The authors evaluated the wear difference between bearing surfaces of stainless steel, cobalt chrome, and titanium alloy. They also compared cemented all-polyethylene molded cups with cemented metal-backed molded acetabular cups. These were compared with molded and machined polyethylene cups. Two patient groups were matched individually for gender, age, weight, and length of followup. Analyses were done using the technique of Livermore et al. The bearing surface evaluation consisted of 3 groups after matching, leaving 77 patients per group. Results showed linear wear rates of 0.06 mm per year, 0.05 mm per year, and 0.08 mm per year for stainless steel, cobalt chrome, and titanium alloy, respectively. The comparison between cemented molded metal-backed and nonmetal-backed acetabular components was not matched, with 134 metal-backed and 99 nonmetal-backed components. Results showed linear wear rates of 0.011 mm per year in the metal-backed group and 0.08 mm per year in the nonmetal-backed group. Results were statistically significant. These results indicate that the metal composition of the femoral bearing surface has minimal, if any, effect on the linear polyethylene wear rate. The method of polyethylene fabrication and the use of metal backing had a significant effect on the polyethylene wear rate in these patient groups. These results suggest that the compression-molded all-polyethylene acetabular component may be optimal for reducing polyethylene wear in total hip arthroplasty.

1. The influence of age and gender on the outcome of total knee arthroplasty was examined in 762 knees (490 patients). 2. Gender was shown not to significantly affect the outcome of total knee arthroplasty. Age was observed to produce a significant difference. 3. These results confirm the clinical expectation that both male and female older patients can expect equally favorable outcomes following total knee arthroplasty.

Seven hundred thirty-two total hip replacements performed from 1970 to 1980 were evaluated for the degree of heterotopic bone formation postoperatively and its effect on long-term mechanical loosening. There were 231 Charnley total hip replacements, of which 152 had no heterotopic bone formation, 58 had Grade 1 formation, and 21 had Grade 2 or 3 formation. Among the 123 Mueller total hip replacements, 98 had no heterotopic bone formation, 19 had Grade 1 formation, and 6 had Grade 2 or 3 formation. For the 378 T-28 total hip replacements, there were 305 with no heterotopic bone formation, 59 with Grade 1 formation, and 14 with Grade 2 or 3 formation. Survival analyses using the definition of failure as loosening, fracture, or revision of the acetabulum or femoral components were constructed. There was no correlation between mechanical loosening, fracture, or revision of the total hip replacement and any degree of heterotopic bone formation.

The increasing use of a cementless acetabular component with a total hip replacement requires the need for metal backing, but metal backing with cement in the author's use has been less than optimal. The intention, therefore, was to evaluate all cemented acetabular components, with and without metal backing, used by the author, to offer a standard by which other acetabular components can be compared. From 1969 to 1983, 238 Charnley, 141 Mueller, 555 T-28, 100 Miami Orthopaedic Surgical Clinic total hip replacements with cemented all-polyethylene acetabula, and 134 Miami Orthopaedic Surgical Clinic total hip replacements with a cemented metal-backed acetabula were performed and followed from 1 to 22 years. The cemented acetabular component failure rates for the Charnley, T-28, and all-polyethylene Miami Orthopaedic Surgical Clinic were 14%, 10%, and 9%, respectively. There was a 20% failure rate in the Mueller and metal-backed Miami Orthopaedic Surgical Clinic acetabular components. The Charnley (p0.0001), T-28 (p0.0001), all-polyethylene Miami Orthopaedic Surgical Clinic (p0.0001), and Mueller (p0.012) total hip replacements demonstrated statistically improved survival rates as compared with the metal-backed Miami Orthopaedic Surgical Clinic acetabular components. The Charnley (p0.0001) and T-28 (p0.0003) sockets survived statistically better than the Mueller sockets.(ABSTRACT TRUNCATED AT 250 WORDS)

From 1975 to 1983, 278 patients received 418 posterior cruciate ligament-retaining Total Condylar knee arthroplasties. Twenty-four patients were excluded, 15 for lack of followup data, 6 for infection during followup, and 3 for revision surgeries for previous infections. The 394 remaining knees were observed from 1 to 18 years (mean, 8.08 years). Kaplan-Meier and crude survival estimates at 12 years were 96.8% and 98.1%, respectively. Various survival analyses by other authors have yielded similar successful results.

Four hundred twenty-one posterior cruciate condylar total knee arthroplasties were performed between 1975 and 1983. Anatomic alignment of the knee was recorded on follow-up evaluations from two months to 13 years postoperatively. Patients were stratified into a normal group that was 5 degrees to 8 degrees anatomic valgus, a varus group that was from 4 degrees anatomic valgus to any degree of varus, and a valgus group that was more than 9 degrees anatomic valgus. There were eight failures, five in the varus group and three in the normal group. There were no failures in the valgus group. Kaplan-Meier survival curves showed no significant difference between normal and valgus groups; however, there was a statistical difference between the valgus and varus and the normal and varus groups. A surgeon should align a total knee prosthesis in neutral or a slight amount of anatomic valgus to give the patient the best chance for long-term survival.

The authors discuss the use of lateral heel wedges in the treatment of medial osteoarthritis of the knee in 121 knees in 85 patients. Follow-up was an average of 12 months after the insertion of the wedge. Patients' roentgenograms were graded according to the Ahlback classification, and various improvements were noted. Overall, 38% of patients improved to a Hospital for Special Surgery pain score of 25 or 30, which corresponds to an excellent result from total knee arthroplasty. Fifty percent of patients improved to a pain score of 20 or higher, which corresponds to a good result from total knee arthroplasty. The patients with milder osteoarthritis received greater pain relief. However, even patients with complete loss of joint space and bony erosion showed some improvement. It appears that the use of lateral wedges has a place in the conservative treatment of medial osteoarthritis.

The effect of short-term postoperative treatment with nonsteroidal antiinflammatory medication to prevent the formation of heterotopic ossification (HO) after total hip arthroplasty (THA) was studied in two groups of patients. Group A included 46 noncemented THAs in 40 men. Eight patients (13 hips) received prophylaxis with 25 mg of indomethacin three times daily for 14 days, and 32 patients (33 hips) received prophylaxis of 650 mg of aspirin twice daily for six weeks. Six to 12 months after surgery, only one hip (aspirin treated) developed HO, this being Grade I. In group B, 17 hips in 17 patients with cemented THA received prophylaxis of 25 mg of indomethacin three times daily. Of these, 12 patients were given indomethacin from one to nine days. One year after surgery, five hips had no HO and seven hips showed a Grade I or Grade II lesion. The remaining five patients in Group B received indomethacin from 19 to 26 days; one developed HO. This study demonstrated that treatment with either 650 mg of aspirin twice daily for six weeks or 25 mg of indomethacin three times daily for the first 14 postoperative days is sufficient to prevent the formation of severe HO after THA.

Possible metabolic changes during chronic treatment is of specific importance for the development of antihypertensive drugs. The impact of a combination treatment with co-dergocrine mesilate/nifedipine (Pontuc; CAS 8067-24-1 resp. CAS 21829-25-4) on the lipid metabolism as well as hematological and biochemical values was evaluated in a group of hypertensive patients. HDL-cholesterol remained unchanged, whereas total cholesterol and LDL-cholesterol slightly decreased, apoprotein AI increased and apoprotein B decreased. In conclusion the results of this study indicate that co-dergocrine mesilate/nifedipine has no negative impact on the lipid metabolism in patients with essential hypertension.

The results of revision total knee arthroplasty (TKA) have been documented reasonably well in the literature. It is notable, however, that none of these reports have used the technique known as survival analysis to compare virgin and revision arthroplasties. This technique has an advantage over conventional analyses because it does not exclude patient data for inadequate follow-up study or patient death. In this study, survival analysis was applied to 37 revision TKAs performed exclusively by the senior author. With failure defined as removal of the prosthesis, revision surgeries experienced a 97.0% survival rate at 6 years. The secondary arthroplasty demonstrated a significantly lower survival rate than the index procedure over a period of approximately 6 years.

Seventy-two cementless tricompartmental total knee arthroplasties were performed in 47 patients using a porous-coated prosthesis without screw fixation for the tibial components between 1984 and 1986. These individuals were observed at regular intervals for a minimum of three years. Their Hospital for Special Surgery pain and function scores as well as roentgenographic signs of anatomic alignment and subsidence were evaluated at six months, one year, and three years postoperatively. The roentgenographic evaluation for subsidence looked at a measurable difference in the anteroposterior roentgenograph on the medial and lateral plateaus and on the lateral roentgenograph anteriorly and posteriorly. Early postoperative interpretations have suggested pain and knee scores to be much lower than scores in the cemented prosthesis. Reassessment after three years, however, revealed no further deterioration of the noncemented prosthesis in respect to knee scores and survival analysis. Roentgenographic analysis showed no correlation between subsidence and alignment alterations, subsidence and time, or subsidence and pain. It appears that after an initial period of discomfort, the noncemented knee can achieve a functional, clinical, and roentgenographic result much better than previously anticipated. The consequences beyond this time period still remain unknown.

A retrospective clinical and radiographic review of 25 conventional cementless total hip replacements (THRs) and 25 cementless hydroxyapatite-coated THRs was performed to evaluate early postoperative results. The hydroxyapatite-coated group had a higher incidence of pain-free arthroplasties compared with the standard cementless group (72% v 44%, P = .045) at the 2-month postoperative evaluation. At the 6-month evaluation, 76% of hydroxyapatite-coated THRs were pain-free compared with 52% of conventional cementless THRs, although the statistical significance disappears (P greater than .05). No differences between groups existed in the 6-month Harris hip scores, average motion, use of external support, Trendelenberg gait, postoperative implant radiolucent lines. Adding a 50- to 75-mug hydroxyapatite coating to a proximal one-third porous femoral prosthesis and porous surface acetabular cup improved the early clinical results in cementless THR. Whether this improvement in pain scores reflects a more stable cementless prosthesis via increased rates and amount of osseus ingrowth or adjunctive bone hydroxyapatite chemical bonding remains unanswered. Long-term follow-up of femoral subsidence and THR revision is needed to indicate the durability and success of hydroxyapatite coating.

We evaluated the results of twelve hematological and plasma protein determinations in 450 to 500-milliliter volumes of shed blood that had been collected with or without acid-citrate-dextrose anticoagulant (National Institutes of Health Formula A) from knees and hips during the first twelve hours after arthroplasty. We also evaluated the effects on the recipients when the blood was used for reinfusion. The findings in the units that had been obtained in less than four hours, in between four and six hours, and in more than six hours after the arthroplasty were similar whether or not the acid-citrate-dextrose anticoagulant had been used. The mean values for the collected units were: in the blood, a concentration of hemoglobin of 115 grams per liter, a hematocrit of 0.34, a white blood-cell count of 4.8 x 10(9) per liter, and a red blood-cell count of 3.7 x 10(12) per liter, and, in the plasma, a level of hemoglobin of 160 grams per liter, a level of fibrinogen of less than 0.2 gram per liter, a level of factor-V clotting protein of less than 10 per cent of normal, a level of factor-VIII clotting protein that was 45 per cent of normal, a level of antithrombin III that was 45 per cent of normal, a level of plasminogen that was 55 per cent of normal, a level of protein C that was 100 per cent of normal, and a level of fibrin-degradation products of 1000 micrograms per milliliter of plasma. The clinical response of the patient was assessed after the reinfusion of a total of 205 units of unwashed shed blood into 153 patients. In addition, in 126 of the 153 patients, hematological and plasma-protein measurements were analyzed before the autotransfusion and one and twenty-four hours afterward. Each of these patients had received one to four units of shed blood that had been filtered but not washed. Only two (2 per cent) of the ninety-nine patients who received shed blood that had been collected six hours or less after the operation had a febrile reaction, whereas twelve (22 per cent) of the fifty-four patients who received blood that had been collected six to twelve hours after the operation had such a reaction.(ABSTRACT TRUNCATED AT 400 WORDS)

A retrospective analysis of 144 total knee arthroplasties was performed between 1975 and 1981 with a minimum follow-up period of seven years. A posterior cruciate condylar prosthesis was used in each procedure. Patients were followed clinically and roentgenographically, and a set of statistical variables was established based on elevation in joint line, tibial component angular alignment, overall limb alignment, and position of the tibial component on anteroposterior and lateral roentgenograms. Review of the study group found that the Hospital for Special Surgery knee scores improved from a preoperative score of 55 to a postoperative score of 88, with 94.5% having good or excellent results. The mean postoperative range of motion was 106 degrees with a mean extension of -0.3 degrees. Radiolucencies developed in 41% of the knees with 5% of the knees having progressive radiolucencies. Eight knees were considered failures based on clinical and roentgenographic evaluations. Factors found to significantly affect the formation of radiolucent lines included a shift of the tibial component medially by greater than 4 mm, a varus tilt of the tibial component greater than 2 degrees, and the diagnosis of rheumatoid arthritis. The only variable associated with aseptic loosening was an elevation of the joint line by greater than 8 mm.

A Kaplan-Meier survival analysis of 240 Charnley, 149 Mueller (Depuy, Warsaw, IN), 576 Trapezoidal 28 (Zimmer, Warsaw, IN), and 100 Miami Orthopaedic Surgical Clinics (Biomet, Warsaw, IN) cemented total hip replacements with all polyethylene acetabular components, performed by the senior author (M.A.R.) should be the basis that all noncemented total hip replacements must exceed to be a reasonable alternative. Failure, ie, revision and a loose prosthesis, shows that 80%, 61%, and 63% of the Charnley, Mueller, and Trapezoidal 28, respectively, survive longer than 15 years. The Miami Orthopaedic Surgical Clinics prosthesis, which uses current cement technology, has been observed for only 8 years. Despite the fact that there are no differences noted between all four prostheses at 8 years, more time is needed to judge the usefulness of current cement technology.

Sixty-four Indiana conservative (Depuy, Warsaw, IN) hip arthroplasties performed in 61 patients were reviewed for loosening, mechanisms of loosening, and revision rate. Mean follow-up time was 6.8 years. There were revisions in 26 hips (40.6%) with 4 hips awaiting revision, yielding a total of 30 hips (47%) defined as failures. Acetabular failure occurred in 20 hips, femoral failure in 18, and combined failure in 13. Failure of this prosthesis persists over time. There seems to be little or no place for this design in contemporary hip joint arthroplasty.

A radiographic examination of 91 uncemented hemispheric titanium alloy acetabular components and 85 straight-stemmed titanium alloy femoral components was performed. Analysis included zonal radionuclides, migration, bone changes, and fit. Correlation of these parameters were made. Acetabular radiolucencies were common in zone 3 but none were progressive; also, they were unrelated to number and position of screws. Two acetabuli were considered to demonstrate loosening. Femoral changes of calcar atrophy, distal cortical hypertrophy, and distal femoral capping were independent of bone type and distal fit. One component subsided. Proximal radiolucency occurred in three patients, all on the lateral surface. Bony changes around the prostheses were statistically not related to bone type.

A radiographic analysis was done of 83 primary hip arthroplasties performed in 70 patients. The arthroplasty consisted of a truncated acetabular cup and a cemented titanium femoral stem. The patients were evaluated at an average of 3.3 years postoperatively (range 2 to 5 years). Using the method of DeLee and Charnley, the acetabulum was divided into three zones. Specific attention was focused on the percentage of fill in the threads of zones 1 and 3 and the measurement of radiolucency in zone 2. Over time, a large percentage of the acetabulae showed both a decrease in bone fill in zone 3 and an increase in radiolucency in zone 2. By the third postoperative year, 16% (11 of 70) of the acetabulae had migrated. Although all the hips had been rated good or excellent on the Charnley hip score, ie, receiving a 5 or better, 11 had migrated and 3 had been revised, indicating an unacceptable failure rate of the acetabular component.

Porous-surfaced femoral components were approved by the United States Food and Drug Administration for implantation with polymethyl methacrylate cement in total hip arthroplasty. The ability of porous coating to prevent loosening of prostheses in vivo has not been reported in the literature previously. This study compared the radiographic and clinical success of two structurally similar prosthetic designs, one of which incorporates a porous coat. Kaplan-Meier survival analysis showed no significant difference between the components (P greater than .05) when failure is defined as revision alone, radiolucency alone, or the combination of revision and radiolucency.