Aspirin is an Effective Prophylaxis for Venous Thromboembolism After Revision Hip and Knee Arthroplasty.

BACKGROUND: Venous thromboembolism (VTE) following revision total joint arthroplasty (TJA) poses significant risks despite prophylactic measures. The optimal VTE prophylaxis agent for revision TJA remains unclear. This study aimed to compare aspirin against various anticoagulant agents regarding efficacy and safety in preventing symptomatic VTE events after revision TJA. METHODS: A retrospective analysis included 4,575 patients undergoing revision TJA between 2008 and 2020. Of these, 2,091 received aspirin, while 2,484 received other anticoagulants. Demographic, procedural, and outcome data were collected. Logistic regression models were used to identify predictors of symptomatic VTE. RESULTS: The aspirin group showed a significantly lower incidence of symptomatic VTE compared to the other anticoagulant group (0.53 versus 2.54%, P < .001). Logistic regression confirmed a higher risk of VTE with other anticoagulants (odds ratio: 0.2 to 0.26, P < .001), while blood transfusion (odds ratio: 2.72, P = .001) were identified as risk factors. CONCLUSIONS: This study demonstrated that aspirin is a viable and potentially safer option than other anticoagulants, exhibiting comparable efficacy in preventing VTE events in revision TJA. Balancing effectiveness and safety is crucial, considering patient-specific risk factors and bleeding tendencies. This large cohort study demonstrated that aspirin was associated with a more effective and safer VTE prophylaxis agent, compared to other anticoagulants, in patients undergoing revision TJA.

Development and Validation of a Risk Calculator for Intensive Care Unit Admission After Total Hip Arthroplasty.

BACKGROUND: The purpose of this study was to develop and validate a risk stratification calculator to determine the risk of a patient requiring intensive care unit (ICU) admission following primary and revision total hip arthroplasty (THA). METHODS: Using a database of 12,342 THA procedures, with 132 ICU admissions, from 2005 to 2017, we developed models of ICU admission risk based on previously identified preoperative factors including age, heart disease, neurologic disease, renal disease, unilateral versus bilateral surgery, preoperative hemoglobin, blood glucose, and smoking status. Prior to developing the calculator, a set of logistic regressions were analyzed to determine weight and scoring for each variable. Once developed, we validated the risk calculator using a second independent institution. RESULTS: A separate risk calculator was developed for primary and revision THA. The area under the curve (AUC) for primary THA was 0.808 (95% confidence interval 0.740 to 0.876) and revision THA was AUC 0.795 (confidence interval 0.740 to 0.850). As an example, the primary THA risk calculator had a Total Points scale of 220, with 50 points associated with a 0.1% chance of ICU admission and 205 points associated with a 95% chance of ICU admission. Validation with an external cohort demonstrated satisfactory AUCs, sensitivities, and specificities for both primary THA (AUC 0.794, sensitivity 0.750, and specificity 0.722) and revision THA (AUC 0.703, sensitivity 0.704, and specificity 0.671) CONCLUSION: The externally validated risk calculators developed in this study can accurately predict ICU admission following primary and revision THA based on a number of readily available preoperative factors.

Routine Use of Closed Suction Drains Following Revision Arthroplasty May Not be Necessary.

BACKGROUND: There are numerous studies demonstrating that closed suction drainage (CSD) usage after primary total joint arthroplasty (TJA) has little to no benefit. There are little data on the role of CSDs after revision TJA. The purpose of our study was to evaluate whether there is any clinical advantage to CSD usage after revision TJA. METHODS: This retrospective study evaluated the clinical records of 2,030 patients undergoing revision TJA between 2007 and 2021. CSD was used in 472 patients and not used in 1,558 patients. Primary outcome was blood transfusion rate and secondary outcomes included total blood loss (TBL), as determined by Gross formula, wound complications (hematoma, infection, and dehiscence), and length of hospital stay. Patients undergoing revision TJA for oncologic reasons or those with incomplete datasets were excluded. RESULTS: There were no statistically significant differences in rates of allogeneic blood transfusion, TBL, and wound complications (hematoma, infection, and dehiscence) between the two groups (P = .159, .983, .192, .334, and .548, respectively). When adjusted for demographic and surgical confounders, there was no difference in transfusion and TBL rates between groups (Odds Ratio 1.04, 95% Confidence Interval 0.78-1.38, P = .780 and estimate -105.71 mL, 95% confidence interval -333.96 to 122.55, P = .364, respectively). CSD cohort had a shorter length of stay (4.30 versus 5.82 days, P < .001). CONCLUSION: We acknowledge that there is a role for CSD usage in a selected group of patients. Nevertheless, our study revealed that routine use of CSD after revision TJA does not provide an additional clinical benefit.

Minimum Five-Year Outcomes of Modular Dual Mobility in Primary Total Hip Arthroplasty.

BACKGROUND: Using a modular dual-mobility (MDM) bearing in primary total hip arthroplasty (THA) has not been widely evaluated. The purpose of this study is to evaluate clinical outcomes and survivorship following MDM bearings in primary THA. METHODS: We used our registry database for patients with an MDM bearing on primary THA, performed by 6 surgeons through supine direct lateral or direct anterior approach. MDM bearings were used most often when impingement or subluxation was present intraoperatively despite proper component position. Another indication was a patient with planned activities who might be at a higher risk of instability postoperatively. RESULTS: A total of 127 MDM bearings were used in primary THA in 119 patients. Mean follow-up was 6.77 years (range 5-8.9). Five hips were revised, none of which were due to MDM bearing failure. Preoperative Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement, Veterans RAND/Short Form 12 Physical Health Score and Mental Health Score increased from 25.81 to 52.40 (P < .0001), 30.42 to 44.50 (P < .0001), and 36.21 to 52.70 (P < .0001) at latest completed survey follow-up, respectively. CONCLUSION: This MDM bearing shows excellent functional outcomes at a minimum 5 years of follow-up with no bearing-related failures. It can be an excellent choice in primary THA specifically in females where the use of increased head size to prevent instability is not possible due to anatomical restrictions and liner thickness.

Low-Dose Aspirin for Venous Thromboembolism Prophylaxis is Associated With Lower Rates of Periprosthetic Joint Infection After Total Joint Arthroplasty.

BACKGROUND: Aspirin as a venous thromboembolism (VTE) prophylactic agent has been shown to have antistaphylococcal and antibiofilm roles. Optimal acetylsalicylic acid (ASA) dosage would facilitate antimicrobial effects while avoiding over-aggressive inhibition of platelet antimicrobial function. Our purpose was to determine the periprosthetic joint infection (PJI) rate after total joint arthroplasty in patients receiving low-dose ASA (81 mg twice a day), in comparison to high-dose ASA (325 mg twice a day). METHODS: We conducted a retrospective cohort study between 2008 and 2020. Eligible patients were older than 18 years, underwent primary total joint arthroplasty, both total knee arthroplasty and total hip arthroplasty, had a minimum 30-day follow-up, and received a full course ASA as VTE prophylaxis. Patients' records were reviewed for PJI, according to Musculoskeletal Infection Society criteria. Patients were excluded if they underwent revision arthroplasty, had a history of coagulopathy, or had an ASA regimen that was not completed. In total 15,825 patients were identified, 8,761 patients received low-dose ASA and 7,064 received high-dose ASA. RESULTS: The high-dose cohort had a higher PJI rate (0.35 versus 0.10%, P = .001). This relationship was maintained when comparing subgroups comprising total knee arthroplasty (0.32 versus 0.06%, P = .019) or total hip arthroplasty (0.38 versus 0.14%, P = .035) and accounting for potentially confounding demographic and surgical variables (odds ratio = 2.59, 95% CI = 1.15-6.40, P = .028). CONCLUSION: Comparing low-dose to high-dose ASA as a VTE prophylactic agent, low-dose ASA had a lower PJI rate. This may be attributable to a balance of anti-infective properties of ASA and antiplatelet effects.

Routine Laboratory Tests are not Necessary After Primary Total Joint Arthroplasty: A Prospective Study Utilizing a Selective Algorithmic Approach.

BACKGROUND: Laboratory tests are obtained following total joint arthroplasty (TJA) despite a lack of supporting evidence. No prior study has prospectively analyzed the effect of discontinuing routine laboratory tests. This study aimed to determine whether discontinuing routine laboratory tests in TJA patients resulted in a difference in 90-day complications. METHODS: This was a prospective protocol change study at a high-volume center. Prior to protocol change, patients underwent routine laboratory tests following primary unilateral TJA (control group). After the change, an algorithmic approach was used to selectively order laboratory tests (protocol group). Patients with bleeding disorders, chronic obstructive pulmonary disease, arrhythmia, coronary artery disease, congestive heart failure, chronic renal failure, dementia, abnormal preoperative sodium, potassium, or hemoglobin <10 g/dL were excluded. In-hospital and 90-day data were collected. Student's t-test was used to analyze continuous variables and chi-squared test was used for categorical variables. A pre-hoc analysis examining the primary outcome required 607 patients per group to achieve 80% power. RESULTS: The protocol group included 937 patients, whereas the control group included 891 patients. The protocol group had fewer females and total hip arthroplasties. There were no differences in age, body mass index, American Society of Anesthesiologists classification, tranexamic acid administration, or estimated blood loss between the protocol and control groups. There were also no differences in transfusions, electrolyte corrections, unplanned consults, length of stay, or transfers. The protocol cohort had more fluid boluses and home discharges. There was no difference in 90-day complications between the 2 groups. CONCLUSIONS: This study utilizing an algorithmic approach to laboratory collection demonstrates that discontinuing routine laboratory tests following TJA is safe and effective. We believe this protocol can be implemented for most patients undergoing primary unilateral TJA.

A New Additive-Manufactured Cementless Highly Porous Titanium Acetabular Cup for Primary Total Hip Arthroplasty-Early Two-Year Follow Up.

INTRODUCTION: Additive-manufacturing technologies are increasingly being used, not only to create acetabular components with porous coating architecture very similar to the complex trabecular structure of cancellous bone, but also for producing the entire implant in a single step. The aim of this study is to assess two-year clinical and radiological outcomes of a new additive-manufactured cup in primary total hip arthroplasty (THA). MATERIALS AND METHODS: We reviewed 266 primary THAs (254 patients) performed in our institution between December 2016 and December 2018 using a new highly porous titanium acetabulum shell fabricated via additive manufacturing. Clinical and functional outcomes were measured using SF/VR-12 and HOOS JR to determine patient satisfaction with surgery. Radiographs were assessed to determine the presence of migration, radiolucency, and loosening. Patients records were reviewed to assess cup survivorship in terms of all-cause revisions and revision for aseptic cup loosening. RESULTS: At a minimum of two-year follow up (range: 2-3.45 years), the patient cohort demonstrated significant improvement in postoperative functional scores (hip disability and osteoarthritis outcome score for joint replacement [HOOS JR.] and clinical scores (12-item short-form health survey [SF/VR-12]) (p<0.001). One cup developed progressive radiolucent lines at the prosthesis-bone interface consistent with loosening and was revised. The overall acetabular component two-year survivorship free of all-cause failure was 97.4% (95% confidence interval [CI]: 95.5-99.4%). When aseptic loosening of the acetabular component was used as the failure endpoint, the two-years survivorship rate was 99.6% (95% CI: 98.9-100%). CONCLUSION: Highly porous titanium cementless acetabular cups produced via additive-manufacturing showed promising early clinical and radiological results in primary THA with low rates of aseptic loosening. Further follow-up studies are needed to assess the long-term survivorship and outcomes of this new acetabular component.

Risk Factors for Unplanned Admission to the Intensive Care Unit After Elective Total Joint Arthroplasty.

BACKGROUND: Despite improved surgical and anesthesia techniques, as well as advances in perioperative protocols, a number of patients undergoing total joint arthroplasty (TJA) are at risk of serious medical complications that require intensive care unit (ICU) admission. With the recent move toward performing TJA in ambulatory surgical centers and on an outpatient basis, it is important to recognize patients that may require intensive care in the postoperative period. This study aimed to identify risk factors for ICU admission following elective total hip (THA) and knee (TKA) arthroplasty. METHODS: We evaluated 12,342 THA procedures, with 132 ICU admissions, and 10,976 TKA procedures, with 114 ICU admissions from 2005 to 2017. Demographic, preoperative, and surgical variables were collected and compared between cohorts using both univariate and logistic regression analysis. RESULTS: For THA, logistic regression analysis demonstrated older age, bilateral procedure, revision surgery, increased Charlson comorbidity index, general anesthesia, increased estimated blood loss, decreased preoperative hemoglobin, and increased preoperative glucose level were independently associated factors for increased risk of ICU admission. For TKA, increased age, increased body mass index, bilateral procedure, revision surgery, increased Charlson comorbidity index, increased estimated blood loss, general anesthesia, and increased preoperative glucose were independently significantly associated with ICU admission. CONCLUSION: In this study, we identify a number of critical independent risk factors which may place patients at increased risk of ICU admission following THA and TKA. Identification of these risk factors may help surgeons safely select those TJA candidates appropriate for surgery at facilities that do not have ICUs readily available.

Clinical Results of Revision Hip Arthroplasty for Neck-Taper Corrosion and Adverse Local Tissue Reactions Around a Modular Neck Stem.

BACKGROUND: Adverse local tissue reactions (ALTRs) around a modular neck stem at our institution lead to a 13.5% rate of revision. The purpose of this study was to report the clinical results of revision total hip arthroplasty (THA) in this patient population. METHODS: We identified 80 hips in 77 patients who underwent revision THA due to neck-stem corrosion. Intraoperative and postoperative complications, clinical outcomes, re-revision rates, and the postoperative ion levels were recorded. RESULTS: The mean follow-up period after revision was 45.3 ± 16.3 months (range 24-81 months). There were no intraoperative mechanical complications during the revision surgery. Eight hips (10%) had postoperative complications related to the revision implant, of which 6/8 came to re-revision: postoperative implant dislocation in 4 hips-2 treated nonsurgically, aseptic loosening of femoral component in 2 hips, and periprosthetic femoral fracture in 2 hips. No patients had recurrence of ALTR nor the recurrence of groin pain within the follow-up period. With 2 exceptions, ion levels normalized within one year of the revision surgery. The survival rate was 94% (95% confidence interval 84-98) at 32 months and 82% (95% confidence interval 56-93) at 63 months after revision THA (using re-revision THA due to any reason as the endpoint). CONCLUSION: Intraoperative complication, postoperative complication, and re-revision rates are equivalent to femoral revision surgeries for other causes (infection, fracture, loosening). We recommend selecting revision-type stems to minimize the risk of femoral loosening or periprosthetic fracture, and larger femoral heads or dual mobility bearings to minimize the risk of dislocation.

Patients With Modular-Neck Total Hip Arthroplasty: A Brief Five-Year Follow-Up Study.

BACKGROUND: We have previously reported the early clinical results of a modular-neck stem identifying an early 2-year revision rate of 13% due to neck-stem corrosion. This report updates our findings to a midterm mean follow-up of 5 years. METHODS: This is a consecutive retrospective review of 186 modular-neck hips in 175 patients with a mean follow-up period was 60.1 ± 22.9 months (range 24-100). We reviewed clinical findings, routine radiographs, detailed imaging (metal artifact reduction software-magnetic resonance imaging, ultrasound), and serum ion levels of cobalt and chromium. We performed a survival analysis with the endpoint defined as revision total hip arthroplasty due to neck-stem corrosion. RESULTS: We revised 41 hips (22.0%) for neck-stem corrosion. Clinical symptoms (groin pain ± local swelling) were consistently present in those that came for revision. Mean serum cobalt ion levels increased as time passed in all patients. Detailed image findings showed that larger fluid collections and local soft tissue masses were seen predominately in symptomatic patients. However, 14% of patients who underwent revision did not have positive magnetic resonance imaging or ultrasound findings. The survival rate was 87% (95% confidence interval 81-92) at 3 years postoperatively and 72% (95% confidence interval 64-80) at 7 years postoperatively. CONCLUSION: The revision rate for this modular-neck stem due to neck-stem corrosion at mid-term follow-up almost doubled in comparison to previous short-term results. It seems reasonable to consider clinical follow-up alone as symptoms, rather than blood testing for ion levels, seem to be the defining characteristic of failure.

Total Hip Arthroplasty After Prior Acetabular Fracture: Infection Is a Real Concern.

BACKGROUND: Acetabular fractures often require surgical intervention for fracture fixation and can result in premature osteoarthritis of the hip joint. This study hypothesized that total hip arthroplasty (THA) in patients with a prior acetabular fracture who had undergone open reduction and internal fixation (ORIF) is associated with a higher rate of subsequent periprosthetic joint infection (PJI). METHODS: About 72 patients with a history of acetabular fracture that required ORIF, undergoing conversion THA between 2000 and 2017 at our institution, were matched based on age, gender, body mass index, Charlson comorbidity index, and date of surgery in a 1:3 ratio with 215 patients receiving primary THA. The mean follow-up for the conversion THA cohort was 2.9 years (range, 1-12.15) and 3.06 years (range, 1-12.96) for the primary THA. RESULTS: Patients with a previous acetabular fracture, compared with the primary THA patients, had longer operative times, greater operative blood loss, and an increased need for allogeneic blood transfusion (26.4% vs 4.7%). Most notably, PJI rate was significantly higher in acetabular fracture group at 6.9% compared with 0.5% in the control group. Complications, such as aseptic revision, venous thromboembolism, and mortality, were similar between both groups. CONCLUSION: The present study demonstrates that conversion THA in patients with prior ORIF of acetabular fractures is associated with higher complication rate, in particular PJI, and less optimal outcome compared with patients undergoing primary THA. The latter findings compel us to seek and implement specific strategies that aim to reduce the risk of subsequent PJI in these patients.

Total Hip Arthroplasty Through the Direct Anterior Approach Using a Bikini Incision Can Be Safely Performed in Obese Patients.

BACKGROUND: Direct anterior approach (DAA) total hip arthroplasty can be performed through a traditional vertical incision or a horizontal (bikini) incision. The purpose of this study is to compare the 2 approaches, performed by a single surgeon past the learning curve, in terms of (1) overall wound complications and (2) patient-reported esthetics at the 6-month follow-up. METHODS: A case-control retrospective study was conducted. Eighty-six bikini DAA patients were matched 3:1 to 230 conventional DAA patients for gender, age, body mass index (BMI), and American Society of Anesthesiologists score. Outcomes evaluated included wound complications, acute periprosthetic joint infection, transfusion, length of surgery, and dysesthesia. A subgroup analysis was also performed on obese patients, BMI greater than 30 kg/m2. Furthermore, the patients rated cosmesis of the incision at 6 months using a Patient Scar Assessment Scale and the Vancouver Scar Assessment Scale. RESULTS: Bikini patients had lower rates of delayed wound healing compared to conventional incision (2.3% vs 6.1%, P = .087). This difference was statistically significant (0% vs 16.6%, P < .05) in obese patients. There was no difference in terms of incision cosmesis between the 2 incision types. CONCLUSION: Our study demonstrates that the DAA total hip arthroplasty can be performed safely through an alternative horizontal bikini incision with complication rates equivalent to conventional incision DAA and to those in other approaches when performed by surgeons in a high volume, efficient hip replacement institution. In patients whose BMI is >30, a potential benefit of the horizontal incision may be lower wound complications. This study design should be performed at other institutions and ideally at a multi-institution level to evaluate if results can be corroborated. Our opinion is that the horizontal bikini incision should be utilized but only after mastery of the DAA approach using the conventional vertical incision.

One- and two-stage surgical revision of peri-prosthetic joint infection of the hip: a pooled individual participant data analysis of 44 cohort studies.

One-stage and two-stage revision strategies are the two main options for treating established chronic peri-prosthetic joint infection (PJI) of the hip; however, there is uncertainty regarding which is the best treatment option. We aimed to compare the risk of re-infection between the two revision strategies using pooled individual participant data (IPD). Observational cohort studies with PJI of the hip treated exclusively by one- or two-stage revision and reporting re-infection outcomes were retrieved by searching MEDLINE, EMBASE, Web of Science, The Cochrane Library, and the WHO International Clinical Trials Registry Platform; as well as email contact with investigators. We analysed IPD of 1856 participants with PJI of the hip from 44 cohorts across four continents. The primary outcome was re-infection (recurrence of infection by the same organism(s) and/or re-infection with a new organism(s)). Hazard ratios (HRs) for re-infection were calculated using Cox proportional frailty hazards models. After a median follow-up of 3.7 years, 222 re-infections were recorded. Re-infection rates per 1000 person-years of follow-up were 16.8 (95% CI 13.6-20.7) and 32.3 (95% CI 27.3-38.3) for one-stage and two-stage strategies respectively. The age- and sex-adjusted HR of re-infection for two-stage revision was 1.70 (0.58-5.00) when compared with one-stage revision. The association remained consistently absent after further adjustment for potential confounders. The HRs did not vary importantly in clinically relevant subgroups. Analysis of pooled individual patient data suggest that a one-stage revision strategy may be as effective as a two-stage revision strategy in treating PJI of the hip.

Computer-Assisted Total Knee Arthroplasty: Is There a Difference Between Image-Based and Imageless Techniques?

BACKGROUND: Image-based and imageless computer-assisted total knee arthroplasty (CATKA) has become increasingly popular. This study aims to compare outcomes, including perioperative complications and transfusion rate, between CATKA and conventional total knee arthroplasty (TKA), as well as between image-based and imageless CATKA. METHODS: Using the 9th revision of the International Classification of Diseases codes, we queried the Nationwide Inpatient Sample database from 2005 to 2011 to identify unilateral conventional TKA, image-based, and imageless CATKAs as well as in-hospital complications and transfusion rates. RESULTS: A total of 787,809 conventional TKAs and 13,246 CATKAs (1055 image-based and 12,191 imageless) were identified. The rate of CATKA increased 23.13% per year from 2005 to 2011. Transfusion rates in conventional TKA and CATKA cases were 11.73% and 8.20% respectively (P < .001) and 6.92% in image-based vs 8.27% in imageless (P = .023). Perioperative complications occurred in 4.50%, 3.47%, and 3.41% of cases after conventional, imageless, and imaged-based CATKAs, respectively. Using multivariate analysis, perioperative complications were significantly higher in conventional TKA compared to CATKA (odds ratio = 1.17, 95% confidence interval 1.03-1.33, P = .01). There was no significant difference between imageless and image-based CATKA (P = .34). Length of hospital stay and hospital charges were not significantly different between groups (P > .05). CONCLUSION: CATKA has low complication rates and may improve patient outcomes after TKA. CATKA, especially the image-based technique, may reduce in-hospital complications and transfusion without increasing hospital charges and length of hospital stay significantly. Large prospective studies with long follow-up are required to verify potential benefits of CATKA.

Routine Workup of Postoperative Pyrexia Following Total Joint Arthroplasty Is Only Necessary in Select Circumstances.

BACKGROUND: It is unclear when routine workup of postoperative pyrexia (POP) following total joint arthroplasty (TJA) should be performed. METHODS: A retrospective electronic database search was conducted on 25,558 consecutive patients undergoing primary or revision TJA between June 2001 and June 2013. We identified patient demographics, procedure type, characteristics of feverish patients, and febrile complications. The estimated costs for chest x-ray (CXR), urinalysis, urine culture, and blood culture were investigated. RESULTS: POP occurred in 46% of TJAs. A total of 11,589 separate workups were performed in 90.5% of POP patients, of which 2.4% were positive. Urinalysis, urine culture, blood culture, and CXR were positive in 38.7%, 9.5%, 7.0%, and 0.2%, respectively. Febrile complications occurred in 4.5% and the infectious complications rate was 2.0%. The positive rate of fever workups was significantly higher in patients with the first POP occurring after postoperative day 3, POP > 102°F, multiple fever spikes, and patients undergoing revision TJA. Multivariate logistic regression revealed that the time of first POP, the maximum temperature, multiple fever spikes, and revision TJA were independent predictors of febrile complications. The estimated cost for 11,319 negative workups in patients with POP was $4,636,976.80, with CXR costing $4,613,182.00. CONCLUSION: Selective workup of POP following TJA should be performed in patients with higher temperatures, fever occurring after postoperative day 3, those with multiple fever spikes, and those undergoing revision TJA. CXR with an extremely low positive rate should not routinely be ordered.

Reduced Incidence of Intraoperative Femur Fracture With a Second-Generation Tapered Wedge Stem.

BACKGROUND: Intraoperative fractures during total hip arthroplasty (THA) are more common when using cementless stems. The purpose of this study was to investigate the impact of a new shorter second-generation cementless, tapered wedge stem with improved proximal femoral fit in reducing the incidence of intraoperative fracture. METHODS: A retrospective study was conducted on primary THA cases performed at a single institution using a first-generation or second-generation cementless stem from 2006-2016. All intraoperative femur fractures were identified, as well as early 30-day postoperative periprosthetic femur fractures, which could represent nondisplaced intraoperative fractures that were initially missed. Risk for intraoperative femur fracture was analyzed using logistic regression, accounting for demographic covariates and surgeon. RESULTS: Of 6473 primary THA performed with a cementless, tapered wedge stem during the study period, 3126 used a first-generation stem and 3347 used a second-generation stem. The incidence of intraoperative fracture was 1.79% for first-generation stems and 0.24% for second-generation stems, representing a 7.5-fold reduction of risk for fracture. After accounting for covariates, the odds of intraoperative fracture were 0.33 using the second-generation stem relative to the first-generation stem (P = .01). However, there was no significant difference in the odds of early 30-day postoperative fractures using the second-generation stem (odds ratio 0.93, P = .56). CONCLUSION: A new second-generation cementless stem resulted in a 7.5-fold decrease in the incidence of intraoperative femur fracture compared with the preceding stem.

Optimizing Mechanical Alignment With Modular Stems in Revision TKA.

BACKGROUND: Although mechanical alignment is critical for optimal function and long-term implant durability, the role of modular stems in achieving ideal alignment is unclear. METHODS: We identified 319 revision total knee arthroplasty from 2003-2013, for which stem length, stem diameter, and stem fixation method were recorded prospectively. Three-dimensional canal-filling ratio, the product of canal-filling ratio at the stem tip in both the anteroposterior and lateral planes, and alignment were measured radiographically. RESULTS: Ideal alignment of the femur was considered to be 95° in the anteroposterior (AP) plane and from 1° of extension to 4° of flexion in the lateral plane, and ideal tibial alignment was considered to be 90° in the AP plane. Even after accounting for difference in stem size and canal-fill, ideal AP alignment was more reliably achieved with press-fit stems. CONCLUSION: Furthermore, increased engagement of the diaphysis and its anatomical axis with canal-filling stems facilitates accurate alignment.

Effect of Stem Size and Fixation Method on Mechanical Failure After Revision Total Knee Arthroplasty.

BACKGROUND: Although the need for stemmed components is well accepted to improve mechanical survival in revision total knee arthroplasty (TKA), the ideal fixation method and stem design remain controversial. METHODS: We performed a retrospective review of 223 patients who underwent revision TKA in whom stemmed components had not been used previously and with a mean follow-up of 61.6 months, including 108 components with fully cemented stems and 316 components with "hybrid" press-fit stems. RESULTS: Based on a time to event model, risk for mechanical failure was equivalent for both cemented and hybrid stems (relative risk, 0.991; P = .98). Young age was the single greatest risk factor for mechanical failure (P = .006). Although there was a trend toward increased failure with cemented stems in patients aged <65 years, there was no significant difference in risk after accounting for covariates (relative risk, 1.4; P = .50). Intramedullary canal fill, not stem length or diameter, was the strongest predictor of failure with hybrid stems, and risk was reduced by 41.2% for each additional 10% canal fill. CONCLUSION: In conclusion, both cemented and hybrid modular stems are viable options in revision TKA. Surgeons should attempt to maximize canal filling of hybrid stems to obtain a solid press-fit. In addition, further studies are needed to evaluate the long-term survival of cemented stem fixation in young patients.

Bilateral Total Hip Arthroplasty: 1-Stage or 2-Stage? A Meta-Analysis.

BACKGROUND: Total hip arthroplasty (THA) is one of the most successful orthopedic surgeries performed in the last 50 years. However, controversies still exist between conducting 1- or 2-stage bilateral THA. METHODS: Using PubMed, Ovid, Embase, and Cochrane library databases, we searched for papers written between January 1995 and October 2015 that contained the following search terms: "one-stage or two-stage" or "simultaneous or staged," and "hip" and "arthroplasty or replacement." A meta-analysis was conducted with the collected pooled data about major and minor systemic complications, surgical complications, and other perioperative data associated with 1- and 2-stage bilateral THA. Statistical analysis was performed by the Mantel-Haenszel method, and the fixed effect model was used to analyze data. RESULTS: There were 13 studies with 17,762 patients who underwent 1-stage bilateral THA and 46,147 patients who underwent 2-stage bilateral THA. One-stage bilateral THA had a lower risk of major systemic complications, less deep venous thrombosis, and shorter operative time compared with 2-stage bilateral THA. There were no significant differences in death, pulmonary embolism, cardiovascular complication, infections, minor complications, and other surgical complications between procedures. CONCLUSION: One-stage bilateral THA was superior to 2-stage bilateral THA in terms of major systemic complication, deep venous thrombosis, and surgical time compared with 2-stage bilateral THA. However, this study does not encourage performing 1-stage over 2-stage bilateral THA. Higher evidence level studies are necessary for further analysis.

Surgical Case Order Has an Effect on the Risk of Subsequent Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) is a serious complication with multiple etiologies. Prior spine literature has shown that later cases in the day were more likely to develop surgical site infection. However, the effect of case order on PJI after TJA is unknown. This study aims to determine the influence of case order, prior infected case, and terminal cleaning on the risk for a subsequent PJI. METHODS: A retrospective, single-institution study was conducted on 31,499 TJAs performed from 2000 to 2014. Case order was determined by case start times per date within the same operating room. PJI was defined by the Musculoskeletal Infection Society criteria. Logistic regression was used to determine risk factors for a subsequent PJI. RESULTS: Noninfected cases followed an infected case in 92 of 31,499 cases (0.29%) and were more likely to develop PJI (adjusted odds ratio [OR], 2.43; P = .029). However, terminal cleaning after infected cases did not affect the risk for PJI in cases the following morning (OR, 1.42; P = .066). Case order had an OR of 0.98 (P = .655), implying that later cases did not have a higher likelihood of infection. CONCLUSION: Although surgical case order is not an independent risk factor for subsequent PJI, TJA cases following an infected case in the same room on the same day have a higher infection risk. Despite improved sterile technique and clean air operating rooms, the risk of contaminating a TJA with pathogens from a prior infected case appears to be high. Terminal cleaning appears to be effective in reducing the bioburden in the operating room.