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Aseptic tibial loosening following primary total knee arthroplasty persists despite technique and device-related advancements. The mechanisms for this mode of failure are not well understood. We hypothesized that knee movement while the cement was curing dispersed lipids at the implant-cement interface and would result in decreased tibial fixation strength.A cadaveric study was performed utilizing 32 torso-to-toe specimens (64 knees). Four contemporary total knee arthroplasty designs were evaluated. Each implant design was randomly assigned to a cadaveric specimen pair with side-to-side randomization. Specimen densitometry was recorded. Each tibial implant was cemented using a standard technique. On one side, the tibial component was held without motion following impaction until complete cement polymerization. The contralateral knee tibial implant was taken through gentle range of motion and stability assessment 7 minutes after cement mixing. Axial tibial pull-out strength and interface failure examination was performed on each specimen.The average pull-out strength for the no motion cohort (5,462 N) exceeded the motion cohort (4,473 N) (P = .001). The mean pull-out strength between implant designs in the no motion cohort varied significantly (implant A: 7,230 N, B: 5,806 N, C: 5,325 N, D 3,486 N; P = .007). Similarly, the motion cohort inter-implant variance was significant (P ≤ .001). Intra-implant pull-out strength was significantly higher in implant A than D. The average pull-out strength was significantly lower in specimens that failed at the implant-cement interface vs bone failures (4,089 ± 2,158 N vs 5,960 ± 2,010 N, P.0025).Knee motion during cement polymerization is associated with significant decreases in tibial implant fixational strength. Reduction in implant pull-out strength was identified with each implant design with motion and varied between designs. Across all tested designs, we recommend limiting motion while cementing the tibial implant to improve fixation strength.

BACKGROUND Two-stage exchange is a commonly used approach for treating chronic periprosthetic joint infections (PJI). A pre-reimplantation threshold value of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to determine infection eradication and the proper timing of reimplantation remains ill-defined. METHODS We retrospectively reviewed 483 potential patients for eligibility. In total, 178 patients were excluded. In addition, 305 joints were eligible who underwent 2-stage revision for prosthetic hip or knee joint infection (PJI). Serum ESR and CRP were recorded at 8 weeks post resection prior to stage 2 reimplantation. ESR and CRP were analyzed with receiver operating characteristic curves (ROC) for response failure. RESULTS In total, 252 patients had resections for chronic infections while 53 septic patients had resections for acute infections. Forty-one of 252 (16.3%) patients failed reimplantation. Median ESR at the time of reimplantation was 17 (normal less than 20 mm/h). Median CRP was 0.6 (normal less than 0.5 mg/dL). ROC plot for response failure in analyzing ESR found an area under the curve (AUC) of 0.47. ROC plot analyzing CRP found an AUC of 0.57. The ratio of ESR/CRP was also utilized and found an AUC of 0.60. All of the AUC data are in the "fail to discriminate category." CONCLUSION Although improvements in serology can be somewhat reassuring, there are no statistically significant values of ESR or CRP that would predict failure of reimplantation in the 2-stage treatment of PJI. Because we are flying blind consideration should be made for mandatory pre-reimplantation aspirates. LEVEL OF EVIDENCE Level IV, Retrospective Case Series.

The purpose of this study is to evaluate the survivorship and radiographic outcomes of a single design of metaphyseal cone used in conjunction with short cemented stems.A retrospective analysis was conducted of revision total knee arthroplasty (rTKA) patients (June 2015 to December 2017) using porous titanium femoral or tibial cones in conjunction with short cemented stems (50-75 mm). Minimum follow-up was 2 years. Survivorship, complications, and a modified Knee Society Radiographic score were analyzed.Forty-nine rTKAs were included in the study (12 femoral cones, 48 tibial cones). Varus-valgus constraint was used in 28 (57%) and a hinged bearing was used in 3 (6%) of these constructs. The majority were index rTKAs of primary components (86%), performed for aseptic loosening (51%) and reimplantation following staged treatment for infection (37%). Median follow-up was 39 months (range 25-58). Using a modified Knee Society Radiographic score, all constructs were classified as stable. Postoperatively, 4 rTKAs were complicated by recurrent infection (8%), periprosthetic fracture 2 (4%), and superficial wound infection 1 (2%). Seven rTKAs (14%) required reoperation. The majority of reoperations (4 rTKAs) were debridement and irrigation with implant retention for infection. Metaphyseal cone constructs with short cemented stems demonstrated 100% survivorship free of revision for aseptic loosening without evidence of radiographic loosening in any case.Our results demonstrate excellent outcomes with the use of metaphyseal cones with short cemented stems at mid-term follow-up. This construct avoids the use of long-stem fixation with the associated extraction difficulty, end of stem pain, and potential for malposition at the joint line.IV, Case Series.

Background Advances in technique and perioperative blood management have improved transfusion rates following unilateral primary total joint arthroplasty and led some centers to change their preoperative blood ordering protocols. The purpose of this study is to determine whether deleting type and screens (T&S) from preoperative order sets was safe for patients undergoing primary total knee (TKA) and total hip arthroplasty (THA) and to identify patients who required allogenic blood transfusion. Methods Prospectively collected data were reviewed to identify any patient with a hemoglobin (Hgb) drawn within 30 days of surgery who received a transfusion following a unilateral primary TKA or THA. Results A total of 1255 patients met inclusion criteria. Of the total, 682 (54%) were TKAs and 573 (46%) were THAs. The mean preoperative Hgb was 11.5 g/dL with an average delta Hgb of 3.6 g/dL on postoperative day 1. No patient required an intraoperative transfusion. Fourteen patients (mean age and body mass index, 67.9 and 29.0) required a transfusion (1.1%) for postoperative blood loss anemia. Of those transfused, 13 (93%) of the patients underwent THA with the mean estimated blood loss of 378.6 mL. The total cost for a patient obtaining a T&S is $191.27. Conclusion In our series, the risk of blood transfusion was rare (1.1%) and occurred only secondary to postoperative blood loss anemia. There were no cases of intraoperative complication requiring urgent or emergent blood transfusion. Removing T&S from standard order sets for patients undergoing primary TKA or THA appears to be a safe and cost-effective practice.

Periarticular needle-based therapies such as dry needling, acupuncture, and genicular nerve radiofrequency ablation are becoming more popular for treatment of knee osteoarthritis. These therapies are also being used after total knee arthroplasty for persistent postoperative pain. Although limited published evidence exists for the risk of periprosthetic joint infection after these procedures, we describe one case of periprosthetic joint infection developing shortly after dry needling and another case developing shortly after genicular nerve blocks. We present details of these 2 cases along with a review of the literature regarding the use of periarticular needle-based therapies after total knee arthroplasty.

Background Revision of monoblock metal-on-metal (MoM) total hip arthroplasty (THA) is associated with high complication rates. Limited revision by conversion to a dual mobility (DM) without acetabular component extraction may mitigate these complications. However, the concern for polyethylene wear and osteolysis remains unsettled. This study investigates the results of DM conversion of monoblock MoM THA compared to formal acetabular revision. Methods One hundred forty-three revisions of monoblock MoM THA were reviewed. Twenty-nine were revisions to a DM construct, and 114 were complete revisions of the acetabular component. Mean patient age was 61, 54% were women. Components used, acetabular cup position, radiographic outcomes, serum metal ion levels, and HOOS Jr clinical outcome scores were investigated. Results At 3.9 years of follow-up (range 2-5), there were 2 revisions (6.9%) in the DM cohort, 1 for instability and another for periprosthetic fracture. Among the formal acetabular revision group there was a 20% major complication rate (23/114) and 16% underwent revision surgery (18/114) for aseptic loosening of the acetabular component (6%), deep infection (6%), dislocation (4%), acetabular fracture (3%), or delayed wound healing (6%). In the DM cohort, there were no radiographic signs of aseptic loosening, component migration, or polyethylene wear. One DM patient had a small posterior metadiaphyseal femur lesion that will require close monitoring. There were no other radiographic signs of osteolysis. There were no clinically significant elevations of serum metal ion levels. HOOS Jr scores were favorable. Conclusion Limited revision with conversion to DM is a viable treatment option for failed monoblock MoM THA with lower complication rates than formal revision. Limited revision to DM appears to be a safe option for revision of monoblock MoM THA with a cup in good position and an internal geometry free of sharp edges or articular surface damage. Longer follow-up is needed to demonstrate any potential wear implications of these articulations.

Background All aspects of the arthroplasty pathway must be scrutinized to maximize value and eliminate unnecessary cost. Radiology providers’ contracts with hospitals often call for readings of all radiographs. This policy has little effect on patient care when intraoperative radiographs are taken and used to make real-time decisions. In order to determine the value of radiologist overreads, we asked 3 questions: what was the delay between the time an intraoperative radiograph was taken and time the report was generated, were the overreads accurate, and what is the associated cost? Methods Two hundred hip and knee radiograph reports generated over 6 months during 391 cases were reviewed. The time the report was dictated was compared to the time taken and time of surgery completion. To determine accuracy, each overread was rated as accurate or inaccurate. The cost of the overread was determined by multiplying the number of radiographs times the radiology fee less the technical fee. Results Median delay between taking the radiograph and filing the report was 45 minutes (range, 0-9778 minutes). Only 31.5% were filed before completion of the procedure. And 18.0% (36/200) were considered inaccurate despite lenient criteria. The reading fee for hip radiographs was $52.00, and for knee radiographs was $38.00, representing a total cost of $10,182 in our select series. This cost projects to $43,614 annually at our facility. Conclusion Radiology overreads of intraoperative radiographs have no effect on real-time decision-making. In the era of value-based care, payors should stop paying for overreads and reimburse providers who actually read the films intraoperatively.

BACKGROUND We analyzed whether the total hospital cost in a 90-day bundled payment period for ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) total hip arthroplasty (THA) bearings was changing over time, and whether the cost differential between ceramic bearings and metal-on-polyethylene (M-PE) bearings was approaching the previously published tipping point for cost-effectiveness of US$325. METHODS A total of 245,077 elderly Medicare patients (65+) who underwent primary THA between 2010 and 2015 were identified from the United States Medicare 100% national administrative hospital claims database. The total inpatient cost, calculated up to 90 days after index discharge, was computed using cost-to-charge ratios, and hospital payment was analyzed. The differential total inpatient cost of C-PE and COC bearings, compared to metal-on-polyethylene (M-PE), was evaluated using parametric and nonparametric models. RESULTS After adjustment for patient and clinical factors, and the year of surgery, the mean hospital cost up to 90 days for primary THA with C-PE or COC was within ±1% of the cost for primary THA with M-PE bearings (P < .001). From the nonparametric analysis, the median total hospital cost was US$296-US$353 more for C-PE and COC than M-PE. Cost differentials were found to decrease significantly over time (P < .001). CONCLUSION Patient and clinical factors had a far greater impact on the total cost of inpatient THA surgery than bearing selection, even when including readmission costs up to 90 days after discharge. Our findings indicate that the cost-effectiveness thresholds for ceramic bearings relative to M-PE are changing over time and increasingly achievable for the Medicare population.

Background The position of the acetabular component in total hip arthroplasty (THA) is critical for success. However, this remains the most variable aspect of the surgery. We hypothesized that there is wide variation in pelvic orientation in the lateral decubitus position. We sought to determine the variability in pelvic positioning and the frequency of pelvic malposition during THA in lateral decubitus with regard to pelvic tilt and pelvic rotation. Methods We analyzed preoperative standing and intraoperative anteroposterior pelvis X-rays in 248 consecutive THAs performed in lateral decubitus by one surgeon. Pelvic tilt and rotation were determined for preoperative and intraoperative X-rays. Proper intraoperative positioning was defined as less than 10° change in tilt or rotation between preoperative and intraoperative X-rays. Results With regard to pelvic tilt, the intraoperative position was proper in 188 (76%) cases. There was a pelvic tilt discrepancy of 10°-20° in 43 (17.5%) cases and greater than 20° in 16 (6.5%) patients. With regard to pelvic rotation, the intraoperative position was proper in 202 (81%) cases. There was a pelvic rotation discrepancy of 10°-20° in 38 (15.4%) cases and greater than 20° in 7 (2.8%) cases. In 248 cases, only 154 (62.1%) had intraoperative positioning within 10° of preoperative tilt and axial rotation. Pelvic malposition occurred in 38% of cases overall. Conclusion There is wide variation in pelvic orientation in lateral decubitus and frequent discrepancy in pelvic tilt and rotation between preoperative and intraoperative anteroposterior X-rays. Anatomic landmarks should be used to guide acetabular component positioning. Level of Evidence III Diagnostic.

Background Patient optimization is becoming increasingly important before arthroplasty to ensure outcomes. It has been suggested that depression is a modifiable risk factor that should be corrected preoperatively. It remains to be determined whether psychological intervention before surgery will improve outcomes. We theorized that the use of preoperative depression scales to predict postoperative outcomes may be influenced by the pain and functional disability of arthritis. To determine whether depression is a modifiable risk factor that should be corrected preoperatively we asked the following questions: (1) What is the prevalence of depression in arthroplasty patients preoperatively? (2) Do depressive symptoms improve after surgery? (3) Is preoperative depression associated with outcome? Methods Patients scheduled for surgery completed a patient health questionnaire (PHQ-9) to assess the presence and severity of depression pre-operatively and one year post-operatively. Results Sixty-five of the 282 patients had a PHQ-9 score >10 indicating moderate depression and 57 (88%) improved to P = .0012). Ten patients had a PHQ-9 score >20 indicating severe depression and 9 (90%) improved to P = .10). Of the 65 patients who had a PHQ-9 score >10 preoperatively, the median postoperative Hip Disability and Osteoarthritis Outcome Score (N = 40) was 92.3, while the median postoperative Knee Injury and Osteoarthritis Outcome Score (N = 25) was 84.6. The median postoperative Hip Disability and Osteoarthritis Outcome Score and Knee Injury and Osteoarthritis Outcome Score in nondepressed patients were 96.2 and 84.6, respectively ( P = .9041). Conclusion By diminishing pain and improving function through arthroplasty, depression symptoms improve significantly. Patients with depressive symptoms preoperatively had similar postoperative outcome scores compared to non-depressed patients. Patients should not be denied surgical intervention through optimization programs that include a depression scale threshold. Level of Evidence III.

Background Two-stage exchange for periprosthetic joint infection (PJI) in total knee arthroplasty (TKA) remains the gold standard treatment in North America. Occasionally, patients with knee PJI are referred for definitive management after resection and antibiotic spacer placement. Currently, little literature exists to suggest how these patients should be managed. The purpose of this study is to report the clinical outcomes of these patients. Methods We retrospectively identified 54 patients (54 knees) from 2000 to 2012 treated for PJI with initial TKA resection and spacer placement performed somewhere other than the definitive treatment center. The mean age at reimplantation was 64 years, with 59% being male. Redebridement and antibiotic spacer exchange was performed for all patients. Mean follow-up was 6.5 years. Results Of the 54 knees, 22 (41%) grew an organism from a culture taken at the time of redebridement and spacer exchange. The most common organism identified at redebridement was Staphylococcus aureus (41%). Obtaining positive cultures at redebridement was not associated with presenting erythrocyte sedimentation rate (P = .46), C-reactive protein (P = .57), or the presence of retained cement (P = .13). Forty-nine of 54 (91%) knees were ultimately reimplanted. Two-year survivorship free of infection in reimplanted knees was 98%. Conclusion Patients referred with an antibiotic knee spacer for PJI have a high rate of positive cultures at the time of redebridement. Neither the presenting serology nor the identification of retained cement was associated with obtaining positive cultures at the time of redebridement. Nevertheless, this unique cohort of patients has favorable outcomes when redebrided with spacer exchange prior to reimplantation.

In an era of innovation in surgical approaches for total hip arthroplasty (THA), there is concern for increasing trends of early failure. The purpose of this study is to evaluate the incidence of early failure of primary THA stratified by surgical approach.A retrospective review was performed on consecutive primary THAs completed from 2007 to 2014 at a high-volume center. THAs were stratified by surgical approach. Only the direct anterior (DAA) and posterior approaches (PA) were included. The primary outcome measure was early revision (5 years). Descriptive statistics were performed using SAS software.In total, 6894 primary THAs performed between 2007 and 2014 were included. Across 2431 DAA THAs and 4463 PA THAs, there were 103 revisions overall. There was no difference in the overall revision rate for DAA THAs (1.69%) compared to PA THAs (1.39%) (P = .33). The DAA had a higher rate of early revisions for femoral component loosening compared to the PA (P = .0003). About 35.7% of DAA THAs were revised for femoral loosening compared to 8% for the PA (P = .0003). Early failure by femoral loosening occurred more often via the DAA in Dorr A bone (P = .03). The PA had a higher incidence of revision for instability (P = .04). There was no difference in modes of failure with regards to time to failure, acetabular loosening, early periprosthetic fracture, or infection.The DAA had a higher incidence of femoral loosening while PA had a higher mode of failure due to instability. Overall revision rates were not statistically different between approaches.

BACKGROUND The purpose of this study is to analyze whether the cost for ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) bearings used in primary total hip arthroplasty (THA) was changing over time, and if the cost differential between ceramic bearings and metal-on-polyethylene (M-PE) bearings was approaching the previously published tipping point for cost-effectiveness of $325. METHODS A total of 245,077 elderly Medicare patients (65+) who underwent primary THA between 2010 and 2015 were identified from the United States Medicare 100% national administrative hospital claims database. The inpatient hospital cost, calculated using cost-to-charge ratios, and hospital payment were analyzed. The differential cost of C-PE and COC bearings, compared to M-PE, were evaluated using parametric and nonparametric models. RESULTS After adjustment for patient and clinical factors, and the year of surgery, the mean hospital cost and payments for primary THA with a C-PE or COC was within ±1% of the cost for primary THA with M-PE bearings (P < .001). From the nonparametric analysis, the median hospital cost was $318-$360 more for C-PE and COC than M-PE. The differential in median Medicare payment for THA with ceramic bearings compared to M-PE was

Consensus regarding femoral stem fixation options in revision total knee arthroplasty remains controversial. Tapered, modular, fluted titanium (TMFT) stems have an excellent track record in total hip arthroplasty for their ability to provide axial and rotational stability in situations of compromised host bone. We present 3 successfully treated cases in which the Food & Drug Administration granted permission to use custom TMFT stems in situations of failed femoral fixation in multiple revised knees. These stems hold promise to achieve stable fixation in revision total knee arthroplasty where host metadiaphyseal bone is deficient. Implant manufactures should consider dedicating future resources to create adapters that can link existing successful TMFT stems currently used in hip arthroplasty to revision total knee components when host bone is severely compromised.

Background One-stage protocols for the management of periprosthetic infection take an extended period of time requiring two separate preps and sets of instruments to ensure optimal sterility. While intraoperative service time is one part of the reimbursement algorithm, reimbursement has lagged behind for single-stage treatment with respect to the time and resources necessary to perform these complex treatment regimens. If one-stage results are shown to be acceptable, but not reimbursed appropriately, surgeons will be discouraged from managing periprosthetic joint infection (PJI) in a one-stage fashion. Methods The reimbursement and operative time for 50 PJI procedures were compared with 250 primary total hips and 250 primary total knees by the same 4 surgeons. Results The average reimbursement for a one-stage knee procedure was $2,597.08, with an average intraoperative service time of 259 minutes ($601.60/h). The average reimbursement for a primary total knee was $2,435.00, with an average intraoperative service time of 100 minutes ($1,461/h). The average reimbursement for a one-stage hip procedure was $2,826.17, with an average intraoperative service time of 311 minutes ($545.24/h). The average reimbursement for a primary total hip was $2,754.71 with an average intraoperative service time of 104 minutes ($1,589.26/h). Conclusion One-stage procedures for PJI are reimbursed at approximately 1/3 the hourly rate of a primary procedure, which may discourage surgeons from selecting this treatment alternative even if recent studies confirm efficacy. Payers should be encouraged to reimburse physicians commensurate with the intraoperative service time needed to perform a one-stage procedure as adoption will decrease morbidity and save the healthcare system financially.

Background Mechanical complications have been underemphasized in reports on total knee arthroplasty (TKA) in obese patients. Noticing an increased prevalence of varus collapse of the tibia in obese total knee patients, we sought to determine if variability in proximal tibial cancellous bone strength played a role in failure. We attempted to define a cancellous threshold above which alternative methods of fixation should be used. Methods One thousand one hundred six revision TKAs from 2004-2014 identified 35 patients with varus collapse of the tibia, defined as a change in component position of >10°. Variables analyzed included weight, alignment, component size, and proximal tibial bone stress. Postoperative alignment was compared with prerevision alignment. To calculate tibial stress the following formula was used: mass (kg) × acceleration of gravity (9.8 m/s 2 )/tibial surface area (mm 2 ) = pascals or N/M 2 . Results Twenty-nine of 35 patients weighed >200 lbs, whereas 17 of 35 patients weighed >250 lbs (range 130-354 lbs). Average body mass index was 40.5 kg/m 2 (range 24-61 kg/m 2 ). Twenty-seven of 35 failed tibial components were in the lower half of the manufacturer's tibial size offering. Postsurgical alignment averaged 4.9° valgus (range 2° varus-7° valgus) and collapsed an average of 14.9° (range 10°-22°) before revision. Proximal tibial bone stress averaged 334,324 Pascals (range 188,524-601,416). Twenty-five of 35 patients had proximal tibial bone stress >300,000 Pascals. Conclusion Despite good initial primary TKA alignment, we report catastrophic varus collapse of tibial components in obese patients with small tibial components. When a cancellous threshold of 300,000 Pascals is exceeded, strong consideration should be given to either optimizing the patient's weight or using a longer tibial stem to dissipate forces on proximal tibia.

Total knee arthroplasty occasionally does not meet expectations. This randomized clinical trial assessed the effect of restoration of the native patellofemoral height on clinical outcomes. Group I underwent standard patellar bone resection; group II underwent modified patellar bone resection that adjusted the amount of anterior condylar bone removed and the anterior flange thickness. There were no differences in anterior knee pain, Western Ontario and McMaster Universities Arthritis Index scores, or Knee Injury and Osteoarthritis Outcome Score scores. Patellofemoral compartment height restoration versus patellar height alone does not appear to significantly reduce pain or improve function.

Regional variations in hospital billing for total joint arthroplasty (TJA) have been reported. It is not clear whether differences exist in hospital charges for TJA based on hospital profit status.Data from the Centers for Medicare and Medicaid Services on Medicare Severity-Diagnosis Related Groups (MS-DRGs) 469 (TJA with comorbidity) and 470 (TJA without comorbidity) for fiscal year 2011 were analyzed. Differences in hospital charges and payments were investigated based on hospital profit status (nonprofit, government, and proprietary). Generalized estimating equations determined differences in charges and reimbursement between hospital types controlling for census region, MS-DRG, and number of discharges.Significant differences in billing between institutions existed with median average hospital charges for nonprofit, government, and proprietary institutions being $70,514.30, $73,540.99, and $113,203.77 (P.0001), respectively, for DRG 469 and $45,363.95, $44,956.57, and $62,715.39 (P .0001), respectively, for DRG 470. Median average Centers for Medicare and Medicaid Services payments for nonprofit, government, and proprietary institutions for DRG 469 were $22,334.34, $21,346.65, and $21,281.30 (P = .017), respectively, and $14,461.95, $14,466.04, and $13,733.62 (P .0001), respectively, for DRG 470. Multivariate analyses indicate that nonprofit hospitals charge 5% more (P = .021) and receive 3% less (P = .011) reimbursement than government hospitals. Proprietary hospitals charge 34% more (P.0001) and receive 7% less (P.0001) reimbursement than government hospitals.Significant differences in hospital charges based on institution profit status were found, with proprietary institutions charging significantly more than nonprofit and government institutions. However, proprietary institutions had the lowest median average reimbursement.

Background The presence of pain as a harbinger of bearing-related problems has recently been challenged. Adverse local tissue reactions (ALTRs) have been noted on cross-sectional imaging even in asymptomatic patients. The purpose of this study was to determine the natural history of such lesions in asymptomatic patients. Methods Eighty-three asymptomatic patients with modular metal-on-metal total hip arthroplasties underwent metal ion reports and metal artifact reduction sequence magnetic resonance imaging (MARS MRI). MARS MRI images were reviewed and evaluated for the presence or absence of an ALTR lesion by a musculoskeletal radiologist and the senior author. We defined an ALTR lesion as abnormal fluid collections, solid or semisolid pseudotumors, or muscle or bone damage and was classified according to the MRI Classification System of Hart et al. In addition, serum cobalt and chromium levels were measured and analyzed at the time of MRI. Results Twenty-six of 83 (31%) asymptomatic patients had cystic lesions identified. All patients with positive MRIs were contacted to have repeat studies a year later. Nineteen of 26 were available for follow-up. Three patients who became symptomatic were revised. Most ALTRs in asymptomatic patients with modular metal-on-metal total hip arthroplasties that underwent repeat MARS MRI decreased in size (15 of 19 [79%]); 3 lesions increased, whereas 1 remained the same. All patients in the series had Co and Cr ion levels below the threshold of 7 ppb. Conclusion Although most cystic lesions decreased in size, vigilance is still required as 3 patients became symptomatic requiring revision.

We sought to compare the efficacy and cost of reinfusion drains vs tranexamic acid (TA) in primary total joint athroplasty (TJA) patients. We randomized 186 primary TJAs (71 hips, 115 knees) to standard drains (61/186), autologous reinfusion drains (60/186), or single dose (20 mg/kg) of TA (65/186). There was a statistically significant (P < .0001) less drop in hemoglobin levels (2.98 mg/dL; range, 0.5-6.10) in the TA group compared with standard drains (P < .0001) and reinfusion drains (P < .0061). There was no significant difference in transfusion rates. At $581.89, the unit cost of the reinfusion system is substantially higher than the standard drain ($7.56) and TA ($35.91/g). The results of this randomized controlled trial demonstrate that TA is more efficacious and provides cost savings compared with reinfusion drains as a blood management tool for TJA.

Use of large-head metal-on-metal (MoM) bearing surfaces in total hip arthroplasty (THA) has created new and unique modes of failure for this type of articulation. These unique modes are in addition to the traditional modes of failure seen in conventional THA, which include instability, osteolysis, infection, iliopsoas tendinitis, aseptic loosening, and periprosthetic fracture. Ion levels and cross-sectional imaging are helpful when evaluating a MoM patient in the identification of adverse local tissue reactions. Unique modes of failure in MoM THA include tissue necrosis, metallosis-induced osteolysis, skin hypersensitivity reactions, and rarely systemic cobaltism. This article outlines the evaluation and treatment of modes of failure in MoM THA.

Risk adjustment is critical when any comparison of hospital or surgeon performance on patient outcomes is being measured. It is equally critical when developing alternative payment models. The purpose of risk adjustment is to level the playing field in making comparisons of outcome either against a benchmark or across individual providers, hospitals, or providers groups. The consequences of not leveling the playing field may lead to the inappropriate inference of high quality, that is outcomes are better not because of better quality but because the patients are healthier. Another consequence of not leveling the playing field is the inappropriate inference of low quality, that is outcomes are worse not because of lower quality but because patients are less healthy at the onset. Additionally, caring for those patients with the most severe problems is more expensive and this fact must be taken into account in any alternative payment model. It is critically important that risk adjustment is done properly so that access for patients with the most severe problems will be maintained.

Risk adjustment is critical when any comparison of hospital performance or surgeon performance on patient outcomes is being measured. The purpose of risk adjustment is to level the playing field in making comparisons of outcome either against the benchmark or across individual providers, hospitals, or provider groups. The consequences of not leveling the playing field may lead to the inappropriate inference of high quality, that is outcomes are better not because of better quality but because the patients are healthy. Additional consequence of not leveling the playing field is the inappropriate inference of low quality, that is outcomes are worse not because of lower quality but because patients are less healthy at the onset. Therefore, it is critically important that risk adjustment is done properly so that access for the patients with the most severe problems will be maintained. Surgeons and hospitals should not be discouraged from providing care for these individuals for fear of publicly reporting outcomes that are not properly risk adjusted. To that end, American Association of Hip and Knee Surgeons created a Risk Adjustment Task Force to collaborate with Center for Medicare and Medicaid Services in creating a more robust risk adjustment model to take into account clinical factors and severity of orthopedic disease.

Although regional variations in Medicare spending are known, it is not clear whether regional variations exist in hospital charges for total joint arthroplasty. Data from Centers for Medicare and Medicaid Services (CMS) on Diagnosis Related Groups 469 and 470 (Major Joint with and without Major Complicating or Comorbid Condition) from 2011 were analyzed for variation by region. Drastic variations in charges between institutions were apparent with significant differences between regions for hospital charges and payments. The median hospital charge nationwide was $71,601 and $46,219 for Diagnosis Related Groups 469 and 470, respectively, with corresponding median payments of $21,231 and $13,743. Weak to no correlation was found between hospital charges and payments despite adjustments for wage index, cost of living, low-income care and teaching institution status.

Prosthetic joint infection is devastating complication of total joint arthroplasty and represents a significant burden both financially and to the patient's overall health. Challenges are in part due to difficulty in eradicating the disease and that there is no census in the most economical and effective techniques for treatment. In the United States the treatment standard is a 2-stage exchange in which the components are removed and an antibiotic spacer is placed, several weeks of intravenous antibiotics, and then a second procedure to remove the antibiotic spacer and place the final components. A 1-stage exchange removes the infected components and places new components in the same surgical setting. The success rate are similar between the 2 options but to date no large scale randomized study has been performed, however a 1-stage exchange limits the total number operations, decreases the morbidity associated in between stages, and is associated with a decrease in overall cost. Surgeons treating prosthetic joint infections should consider this technique.

Documentation of medical necessity for arthroplasty has come under scrutiny by Medicare. In some jurisdictions three months of physical therapy prior to arthroplasty has been mandated. The purpose of this study was to determine the efficacy and cost of this policy to treat advanced osteoarthritis. A systematic review was performed to assimilate efficacy data for physical therapy in patients with advanced osteoarthritis. The number of arthroplasties performed annually was obtained to calculate cost. Evidence-based studies documenting the efficacy of physical therapy in treating advanced arthritis are lacking with a potential cost of 36-68 million dollars. Physical therapy mandates by administrative contractors are not only ineffective but are costly without patient benefit. Medical necessity documentation should be driven by orthopedists not retroactively by Medicare contractors.

Knee osteoarthritis (OA) accounts for more functional disability of the lower extremity than any other disease. We recruited 18 patients with knee OA and 18 healthy age-, height-, mass-, and gender-matched control subjects to investigate the effects knee OA has on select spatial and temporal gait variables during a stair climbing task. No group-by-direction interaction was observed; however, significant effects did occur for group and direction. Specifically, patients with knee OA demonstrated less time in single support, greater time in double support, decreased step length, greater step width, less stride length, decreased total gait velocity, greater total time in support, and less total time in swing, compared with controls. Early-stage knee OA directly influences specific temporal and spatial gait characteristics during stair climbing.

The ASR (articular surface replacement) XL (DePuy, Warsaw, Ind) metal-on-metal hip arthroplasty offers the advantage of stability and increased motion. However, an alarming number of early failures prompted the evaluation of patients treated with this system. A prospective study of patients who underwent arthroplasty with the ASR XL system was performed. Patients with 2-year follow-up or any revision were included. Failure rates, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and radiographs were evaluated. Ninety-five patients (105 hips) were included. There were 16 revisions. Thirteen (12%) were aseptic acetabular failures. Eight were revised for aseptic loosening; 4, for metallosis; 1, for malposition; 2, for infection; and 1, for periprosthetic fracture. Mean time to revision was 1.6 years (0.18-3.4 years). The ASR XL with a revision rate of 12% is the second reported 1 piece metal-on-metal system with a significant failure rate at early follow-up. This particular class of implants has inherent design flaws that lead to early failure.

Irrigation and debridement (I&D) is an attractive treatment alternative for periprosthetic joint infection (PJI). Irrigation and debridement failure rates average 64% (range, 10.5%-84%) and may be associated with causative organism type and virulence. The study objective was to compare revision rates for PJI caused by streptococcal organisms to other organisms treated with I&D. A multicenter retrospective cohort study of 200 consecutive PJIs treated with I&D was performed. Failure was defined as reoperation for PJI. Failure rate for streptococcal infections was 65% (20/31) compared with 71% (84/119) for other organisms. Failure rate for sensitive Staphylococcus was 72% (48/67) compared with a 76% (22/29) failure rate for resistant Staphylococcus. These results indicate that eradication rates of I&D for a streptococcal PJI are comparable with other causative organisms. Irrigation and debridement should play a limited role in the PJI treatment algorithm regardless of organism type.

Demand for primary and revision arthroplasty is expected to double in 10 years. Coincident with this is a decreased interest in arthroplasty by residents. Retirement of arthroplasty surgeons further threatens access. This study determines if supply will meet demand. Survey data were used to calculate the 2016 workforce. Demand in 2016 was estimated using the Nationwide Inpatients Sample. Between 2008 and 2016, 400 arthroplasty specialists and 1584 generalists will enter the workforce. By 2016, 1896 arthroplasty surgeons will retire using 65 years as a conservative retirement age, whereas 4239 will retire using 59 years as a baseline retirement age. In 2016, the model estimated a procedural shortfall ranging from 174,409 (↓18.6%) using conservative retirement assumptions (age, 65 years) to 1,177,761 (↓69.4%) using baseline retirement assumptions (age, 59 years). This economic model predicts a supply side crisis that threatens patient access to specialty care. Immediate steps to stimulate supply must be taken.

To evaluate the effects of the economic downturn on adult reconstruction surgery in the United States, a survey of the American Association of Hip and Knee Surgeons (AAHKS) membership was conducted. The survey evaluated surgical and patient volume, practice type, hospital relationship, total joint arthroplasty cost control, employee staffing, potential impact of Medicare reimbursement decreases, attitudes toward health care reform options and retirement planning. A surgical volume decrease was reported by 30.4%. An outpatient visit decrease was reported by 29.3%. A mean loss of 29.9% of retirement savings was reported. The planned retirement age increased to 65.3 years from 64.05 years. If Medicare surgeon reimbursement were to decrease up to 20%, 49% to 57% of AAHKS surgeons would be unable to provide care for Medicare patients, resulting in an unmet need of 92,650 to 160,818 total joint arthroplasty procedures among AAHKS surgeons alone. Decreases in funding for surgeons and inadequate support for subspecialty training will likely impact access and quality for Americans seeking adult reconstruction surgery.

The study purpose was to analyze current results of modern cementless femoral components in young patients having total hip arthroplasty (THA) or hip resurfacing. Twenty-two studies (n = 5907; hips = 6408) evaluating modern cementless THA in young patients and 15 studies evaluating hip resurfacing (n = 3002; hips = 3269) were included. Meta-analysis techniques were used to pool failure rates. The pooled failure rate for THA using femoral revision for mechanical failure as an end point was 1.3% (95% confidence interval [CI], 1.0%-1.7%) at a mean 8.4 years of follow-up. At a mean of 3.9 years of follow-up, the pooled mechanical failure rate of the femoral component for hip resurfacing was 2.6% (95% CI, 2.0-3.4). In conclusion, the enthusiasm for hip resurfacing should be tempered by these data. Longer follow-up and direct comparison trials are required to confirm these findings.

The purpose of this study was to asses the fate of incomplete seating of press-fit acetabular components. From 1990 to 2002, 587 hip arthroplasties were performed using a single-design acetabular component inserted with a press-fit technique with no additional fixation. Complete radiographic follow-up at a mean 9.2 years was available for 343 cases. One hundred thirty-three acetabular components had incomplete seating on the initial postoperative radiograph and 210 cases had complete seating. Of 133 components, 125 (94%) had evidence of complete zone 2 filling. Zone 2 focal osteolysis was present in 22 patients. There were no intraoperative fractures. No acetabular components were revised for loosening. Incomplete seating of press-fit acetabular components is safe and effective in achieving initial and long-term fixation. Zone 2 lucencies when present initially are not associated with increased failure risks. Vigorous attempts to completely seat the acetabular component appear to be unwarranted.

Computer-assisted surgery (CAS) has been advocated as a means to improve limb and prosthesis alignment and assist in ligament balancing in total knee arthroplasty (TKA). Thus, we sought to examine alignment outcomes in CAS vs conventional TKA. A systematic review of literature from 1990 to 2007 was performed. Direct comparison of alignment outcomes was performed using random effects meta-analyses. Twenty-nine studies of CAS vs conventional TKA were identified, and included mechanical axis malalignment of greater than 3 degrees occurred in 9.0% of CAS vs 31.8% of conventional TKA patients. The risk of greater than 3 degrees malalignment was significantly less with CAS than conventional techniques for mechanical axis and frontal plane femoral and tibial component alignment. Tibial and femoral slope both showed statistical significance in favor of CAS at greater than 2 degrees malalignment. Meta-analysis of alignment outcomes for CAS vs conventional TKA indicates significant improvement in component orientation and mechanical axis when CAS is used.

A retrospective review of patients with joint arthroplasty was performed to determine if body mass index has increased with time and if the body mass index of patients with arthroplasty was significantly different than that of the general population. We also sought to determine if reimbursement kept pace with this growing cohort. The number of obese patients increased from 30.4% in 1990 to 52.1% in 2005 (P < .0001). In 2005, 24% of the general population was obese, whereas 52.1% of arthroplasty patients were obese. Physician reimbursement decreased 38% for knee arthroplasty and 46% for hip arthroplasty and the need for total joint arthroplasty because of these confounding variables will increase exponentially beyond scheduled expectations. Patients and health policy forecasters must understand the interrelationship between obesity and the need for arthroplasty.

The appropriate treatment for the young patient with post-collapse avascular necrosis (AVN) of the femoral head continues to be controversial. Femoral surface replacement (FSR) has emerged as a potential strategy to delay total hip arthroplasty in these patients. Between 1997 and 2003, 37 FSR procedures were performed. Success was defined as patients not requiring revision surgery or having a Harris hip pain score of 30 or greater. Failure was defined as patients having revision surgery or a Harris hip pain score of 20 or less. The overall failure rate based on Harris hip pain scores and revision surgery was 64.8% (24/37 procedures). Fifteen (40.5%) procedures required revision surgery, whereas 9 (24.3%) patients were considered failures based on their pain scores. The purpose of this study was to determine if FSR is a viable option for post-collapse AVN. We conclude that hemiresurfacing for AVN is an unpredictable procedure. This procedure is no longer offered as a treatment option for post-collapse AVN at our institution.

This study evaluates the difficult reconstructive challenge of severe proximal femoral bone loss. We present intermediate-term results of 46 hips with extensive proximal femoral bone loss that underwent revision total hip arthroplasty using cementless distal fixation without supplemental allograft. All were evaluated with the Harris hip score at a minimum of 2 years. Radiographs were assessed using the Engh fixation scale. At a mean of 6.4 (range 2-12) years, 43 of the 46 prostheses were functioning well. Two patients required revision for symptomatic loosening, and 1 prosthesis remains radiographically loose with a fair clinical score. Mean Harris hip score was 77 at last follow-up. There were 6 intraoperative femur fractures, 9 dislocations, 10 cases of severe stress shielding, and no infections.

Periprosthetic osteolysis in total knee arthroplasty (TKA) has become a significant problem. Routine surveillance is warranted to detect problems that may not be symptomatic. The goal of these radiographs is to detect arthroplasty-related bone loss at an early stage to implement strategies to limit its extension. The purpose of this study was to show the extent to which condylar osteolysis can be underestimated on routine radiographs. Two cadaveric femurs were prepared to receive a posterior stabilized (PS) femoral component. A simulated osteolytic lesion was created using acetabular reamers. Lesions of 36 mm not easily discernible on standard anteroposterior and lateral images were easily recognized on oblique films. The oblique radiographs described can help with the early recognition of retrofemoral osteolysis about a posterior-stabilized implant.

A white blood cell count (WBC) of >50000 cell/mm(3) from a knee aspirate with >or=80% polymorphonuclear cells (PMNCs) is suggestive of infection. This study sought to determine if these same criteria were applicable when interpreting aspirates from a total knee. Of 440 revision total knee arthroplasties, 86 patients had preoperative aspirations of the knee before revision. Fifty-five aspirates were from aseptic failures; 31 aspirates were from patients determined to have septic failure. The mean white blood cell (WBC) count in aspirates from the aseptic group was 645 cells/mm(3) (SD = 878). The mean WBC count in the septic group was 25951 cells/mm(3) (SD = 34994; P=

The best bearing to use in the young active population remains unknown because there are currently no evidence-based data to rely on. This article compares the prevalence of periacetabular osteolysis using computerized tomography in patients with metal-on-metal, ceramic-on-ceramic, and metal-on-cross-linked bearings at a minimum 5-year follow-up.

Hip instability is the leading cause of morbidity after total hip arthroplasty. Surgical strategies that have been used to eliminate recurrent instability include component revision, trochanteric advancement, or the use of constrained components. Between 1986 and 1997, 731 revision total hip arthroplasties were performed at our institution. A total of 29 patients underwent modular component exchange to treat hip instability. After revision surgery, 16 of 29 (55%) patients experienced redislocation. Nine (31% overall) patients dislocated repeatedly after modular component exchange. Five of the 9 patients who dislocated repeatedly (17% overall) ultimately required rerevision to obtain stability. Modular component exchange is an unpredictable procedure in definitively solving hip stability problems. The limitations of this procedure in treating this complex multifactorial problem must be understood by patient and surgeon alike. Copyright 2002, Elsevier Science (USA). All rights reserved.

Satisfactory performance of revision total knee arthroplasty (TKA) requires adequate exposure. This article shows the patella inversion method of exposure in a large consecutive series of revision TKAs.Between 1987 and 1999, 420 revision TKAs were performed. Exposure was facilitated by the patella inversion method. No attempt was made to evert the patella. This technique of exposure was used in 95% (397 of 420) of patients. There were no episodes of patellar tendon avulsion in this series. Multiple exposure options are available in revision TKA. Extensile techniques violate the extensor mechanism. For most patients, these methods were unnecessary. The patella inversion method afforded adequate exposure in most patients without violating the extensor mechanism.