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Background: The effect of so-called stuffing of the patellofemoral compartment at the time of total knee arthroplasty (that is, increasing the anterior patellar displacement, the anteroposterior femoral size, or the combined anteroposterior patellofemoral size) has not been well studied. The purpose of the present study was to evaluate the effect of stuffing the patellofemoral compartment on the outcome of primary total knee arthroplasty., Methods: A retrospective review of 1100 primary total knee arthroplasties that had been performed in 1997 and 1998 was conducted. Eight hundred and thirty arthroplasties (75.5%) met the diagnostic and minimum two-year follow-up criteria for inclusion in this report. Radiographic measurements were made to determine preoperative and postoperative anterior patellar displacement, anteroposterior femoral size, combined anteroposterior patellofemoral size, anterior femoral offset, and posterior femoral offset. Regression analysis was performed to determine the effects of changes in these variables on the range of motion, the Knee Society Knee Score, the Knee Society Function Score, the Knee Society Pain Score, and the rate of lateral retinacular release., Results: Preoperative to postoperative changes in anterior patellar displacement, anteroposterior femoral size, combined anteroposterior patellofemoral size, anterior femoral offset, and posterior femoral offset had no clinically meaningful effect on the range of motion of the knee or on any of the Knee Society scores. Increases in anterior patellar displacement were associated with a lower probability of the need for a lateral retinacular release. Increases in measured anteroposterior femoral size were associated with a higher probability of the need for lateral release. Even when combined, however, these relationships explained only 10.1% of the observed variance in the need for lateral retinacular release. Moreover, analyses indicated that patient gender, large as opposed to medium patellar size, and absolute femoral component size influenced the likelihood of lateral release more than did anterior patellar displacement and measured anteroposterior femoral size., Conclusions: Our findings do not support the widely held belief that stuffing of the patellofemoral joint results in adverse outcomes after total knee arthroplasty. Furthermore, the need for lateral release appears to be multifactorial and likely involves a more complex set of factors. Thus, without evidence of other identifiable causes of failure, we do not recommend revision for the treatment of pain of an overstuffed knee joint.

Background: Following total knee arthroplasty, some patients who fail to achieve >90 degrees of flexion in the early perioperative period may be considered candidates for manipulation of the knee under anesthesia. The purpose of this study was to assess the outcomes of manipulation following total knee arthroplasty., Methods: One hundred and thirteen knees in ninety patients underwent manipulation for postoperative flexion of < or =90 degrees at a mean of ten weeks after surgery. Flexion was measured with a goniometer prior to total knee arthroplasty, at the conclusion of the operative procedure, before manipulation, immediately after manipulation, at six months, and at one, three, and five years postoperatively., Results: Eighty-one (90%) of the ninety patients achieved improvement of ultimate knee flexion following manipulation. The average flexion was 102 degrees prior to total knee arthroplasty, 111 degrees following skin closure, and 70 degrees before manipulation. The average improvement in flexion from the measurement made before manipulation to that recorded at the five-year follow-up was 35 degrees (p < 0.0001, paired t test). There was no significant difference in the mean improvement in flexion when patients who had manipulation within twelve weeks postoperatively were compared with those who had manipulation more than twelve weeks postoperatively. Patients who eventually underwent manipulation had significantly lower preoperative Knee Society pain scores (more pain) than those who had not had manipulation (p = 0.0027)., Conclusions: Manipulation generally increases ultimate flexion following total knee arthroplasty. Patients with severe preoperative pain are more likely to require manipulation.

Background: The treatment of a supracondylar femoral fracture following total knee arthroplasty is complicated by the presence of the prosthetic components. Anterior femoral notching during arthroplasty has been implicated as a contributing risk factor for femoral fracture. We retrospectively reviewed the effect of anterior femoral notching on the subsequent occurrence of a periprosthetic supracondylar fracture of the distal aspect of the femur and the outcomes of primary total knee arthroplasty in such patients., Methods: The prevalence and depth of femoral notching were determined on a review of the lateral radiographs by observers blinded to the clinical results of 1089 consecutive total knee replacements performed in 1997 and 1998. Linear and logistic regression modeling was used to analyze the relationship between femoral notching and the prevalence of supracondylar femoral fracture, postoperative range of motion, the Knee Society score, and the Knee Society functional and pain scores., Results: Femoral notching was performed in 325 (29.8%) of the 1089 knees in our series. During an average follow-up period of 5.1 years, only two supracondylar femoral fractures occurred, both in femora treated without notching. Femoral notching was not associated with an increased rate of fracture (p = 1.000) or with significant differences in the measures of outcome (range of motion [p = 0.117], knee score [p = 0.967], functional score [p = 0.861], need for a lateral release [p = 0.234], or postoperative pain [p = 0.948])., Conclusions: This study demonstrated no difference in knees managed with or without notching of the anterior distal aspect of the femur with respect to the occurrence of a supracondylar fracture, range of motion, Knee Society score, Knee Society function, or pain.

Background: The long-term results of total hip arthroplasty without cement have been reported only rarely. The purpose of the present study was to evaluate the minimum ten-year results of primary total hip arthroplasty performed with use of a proximally porous-coated, plasma-sprayed, straight-stemmed, titanium-alloy femoral component., Methods: The clinical and radiographic results of a consecutive series of 105 total hip replacements in ninety-five patients were reviewed ten to twelve years postoperatively. The diagnosis was osteoarthritis for seventy-seven hips (73%). The clinical result was evaluated on the basis of the Harris hip score, complications, and thigh pain. A detailed radiographic analysis was performed at each follow-up visit. Kaplan-Meier analysis was performed to evaluate the survival of the femoral component., Results: The average Harris hip score improved from 46 points preoperatively to 92 points postoperatively. The average pain score at the time of the most recent follow-up was 42 points, with eighty-three hips (79%) rated as pain-free. Thigh pain was identified in only two patients. All radiolucent lines were seen around the tip of the stem. All hips had some degree of femoral remodeling consistent with osseous ingrowth. No femoral component was revised, and no femoral component had evidence of loosening. Eight acetabular components were revised because of loosening and wear, and one was revised because of recurrent dislocation. One focal femoral osteolytic lesion was seen., Conclusions: This femoral component afforded durable fixation at ten to twelve years after primary total hip arthroplasty., Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Background: While high success rates have been achieved in association with other all-polyethylene tibial components, an alarming number of failures have occurred at our institution in association with the use of an all-polyethylene version of the AGC tibial component. The purpose of the present study was to describe the survival of the AGC all-polyethylene tibial component., Methods: Five hundred and thirty-six AGC all-polyethylene tibial components were implanted in 405 patients and were followed over a ten-year period. The average age of the patients at the time of surgery was 70.3 years, the average weight was 78 kg, and the most common diagnosis was osteoarthritis (prevalence, 92.9%). A clinical and radiographic analysis was performed, Knee Society knee and function scores were determined, and Kaplan-Meier survivorship analysis was conducted. Failure was defined as aseptic loosening as evidenced by progressive radiolucent lines and/or revision due to aseptic loosening or collapse., Results: A high rate of failure was noted in the early postoperative period, with a survival rate of 90.04% (95% confidence interval, 87.35% to 92.72%) after three years. At ten years, the survival rate was 68.11% (95% confidence interval, 57.57% to 78.65%). Fifty-eight (73.4%) of seventy-nine failures occurred in association with loosening or collapse of the bone beneath the medial tibial plateau., Conclusion: While some all-polyethylene tibial designs have been successful, the low success rate among knees treated with the AGC all-polyethylene tibial component suggests that the results associated with all-polyethylene tibial components are design-sensitive., Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Background: The outcome of total knee replacement after high tibial osteotomy remains uncertain. We hypothesized that the results of total knee replacement with or without a previous high tibial osteotomy are similar., Methods: The results of a consecutive series of thirty-nine bilateral total knee arthroplasties performed with cement at an average of 8.7 years after unilateral high tibial osteotomy were reviewed. There were twenty-seven men and twelve women. Preoperatively, the knee scores according to the system of the Knee Society were similar for all of the knees; however, valgus alignment and patella infera were more common in the knees with a previous high tibial osteotomy. Bilateral total knee replacement was staged in seven patients and was simultaneous in thirty-two patients. The results of the total knee arthroplasties were retrospectively reviewed with respect to the knee and function scores according to the system of the Knee Society, the radiographic findings, and the complications., Results: Intraoperatively, no notable differences were identified in the number of medial, lateral, or lateral patellar releases required. However, less lateral tibial bone was resected in the group with a previous high tibial osteotomy (average, 3.3 millimeters) than in the group without a high tibial osteotomy (average, 7.5 millimeters). The average duration of follow-up was 7.5 years (range, three to sixteen years) in the group with a previous high tibial osteotomy and 6.8 years (range, two to ten years) in the group without a high tibial osteotomy. At the time of the final follow-up, the knee and function scores were similar for the two groups (89.0 and 81.0 points, respectively, for the group with a previous high tibial osteotomy, and 89.6 and 83.9 points, respectively, for the group without a high tibial osteotomy). Although more knees were free of pain in the group without a previous high tibial osteotomy (thirty-six) than in the group with a previous osteotomy (thirty-three), this difference was not found to be significant with the numbers available (p = 0.4810). Knee alignment and stability, femoral and tibial component alignment, and range of motion also were similar in both groups postoperatively. One allpolyethylene tibial component was revised in the high tibial osteotomy group. Two knees in each group required manipulation. There were no deep infections., Conclusions: While patients with a previous high tibial osteotomy may have important differences preoperatively, including valgus alignment, patella infera, and decreased bone stock in the proximal part of the tibia, the present study suggests that the clinical and radiographic results of primary total knee arthroplasty in knees with and without a previous high tibial osteotomy are not substantially different. In our relatively small group of patients, the previous high tibial osteotomy had no adverse effect on the outcome of the subsequent total knee replacement.

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.

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.

We prospectively randomized 415 total joint replacements for either a closed wound-drainage system or no postoperative drainage. Drainage was not used in 200 total joint replacements, of which 138 were total knee replacements and sixty-two, total hip replacements. Drainage was used in 215 total joint replacements, of which 137 were total knee replacements and seventy-eight, total hip replacements. All patients were evaluated for the presence of excessive postoperative drainage that necessitated cessation of the range-of-motion exercises, the amount of transfused blood (homologous and autologous), and the preoperative and postoperative hemoglobin levels. The range of motion was assessed daily in the patients who had a total knee replacement. No statistical difference was found in the number of patients who had excessive postoperative drainage from a drained or non-drained wound. There was also no statistical difference with respect to the amount of transfused blood and the preoperative and postoperative hemoglobin levels. Furthermore, in the patients who had a total knee replacement, there were no statistical differences between drained and non-drained wounds with respect to the daily range of motion during the first seven days postoperatively. The mean amount of blood transfused was 157 milliliters in the total knee replacements with drains, 160 milliliters in the total knee replacements without drains, 188 milliliters in the total hip replacements with drains, and ninety-three milliliters in the total hip replacements without drains.(ABSTRACT TRUNCATED AT 250 WORDS)

Three hundred and sixty-three knees (221 patients) that had been treated with total arthroplasty between 1975 and 1985 were divided into three groups on the basis of the preparation of the surface of the bone and the technique of the cement application. Group 1 (155 knees) was treated with irrigation of the bone surfaces with a syringe and manual packing of the bone cement. Group 2 (sixty-one knees) had high-volume, high-pressure lavage of the bone surfaces and manual packing of the cement. Group 3 (147 knees) had high-volume, high-pressure lavage and pressure injection of low-viscosity methylmethacrylate cement. Radiolucency was evaluated at each follow-up interval, and the findings were subjected to chi-square analysis and Kaplan-Meier survival analysis. Chi-square analysis of the data at one and three years indicated a significantly higher frequency of lines at the bone-cement interface in the femur and tibia in Group-1 knees compared with those in Groups 2 and 3. The survival curves showed increasing rates of radiolucency adjacent to the tibial components of the knees that had been prepared with lavage that was not high-volume and high-pressure and that had been prepared with finger-packing of cement (Group 1). This may partially explain the clinical problem of loosening of tibial components despite acceptable alignment. This study demonstrates that proper preparation of the cancellous bone and pressurization of the cement reduce the initial occurrence of a radiolucent line, which may have a positive effect on the ultimate failure of at least the tibial component.

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)

Metal backing for the acetabular component of a total hip replacement, initially designed to allow replacement of the polyethylene liner, has since been universally accepted as a means of decreasing peak stresses at the interfaces of bone and cement. We studied the results of 238 total hip replacements that had been performed between 1980 and 1983 and that differed only in that 138 of the acetabular components had a metal backing and 100 were made of polyethylene only. Kaplan-Meier survival analysis, with three different modes of failure (radiolucency, loosening, and revision), showed a significant increase in the rate of failure of the metal-backed acetabular cup compared with the all-polyethylene cup: radiolucency, 39 compared with 23 per cent (p less than 0.0001); loosening, 4 compared with 2 per cent (p less than 0.0001); and revision, 6 compared with 2 per cent (p less than 0.0034). It was concluded that metal backing cannot be recommended for a cemented acetabular component of a total hip-replacement system.

The anatomical structures adjacent to fourteen acetabula were studied to identify structures that are at risk from acetabular screws. There were six embalmed acetabula, four acetabula from two fresh autopsy specimens, and four acetabula that were studied during two gynecological operations. Models were constructed to show where these screws can penetrate. Medially placed screws either penetrated or came dangerously close to the external iliac vein; the obturator artery, nerve, and vein; and tributaries of the internal iliac vein. To avoid injury to the medial vascular structures, screws should not be placed in the anterosuperior quadrant of the acetabulum.

The performance of carbon fiber-reinforced ultra-high molecular weight polyethylene was compared with that of plain (non-reinforced) polyethylene on the basis of the damage that was observed on the articulating surfaces of retrieved tibial components of total knee prostheses. Established microscopy techniques for subjectively grading the presence and extent of surface damage and the histological structure of the surrounding tissues were used to evaluate twenty-six carbon fiber-reinforced and twenty plain polyethylene components that had been retrieved after an average of twenty-one months of implantation. All of the tibial components were from the same design of total knee replacement. The two groups of patients from whom the components were retrieved did not differ with regard to weight, the length of time that the component had been implanted, the radiographic position and angular alignment of the component, the original diagnosis, or the reason for removal of the component. The amounts and types of damage that were observed did not differ for the two materials. For both materials, the amount of damage was directly related to the length of time that the component had been implanted. The histological appearance of tissues from the area around the component did not differ for the two materials, except for the presence of fragments of carbon fiber in many of the samples from the areas around carbon fiber-reinforced components.