Novel Acetabular Cup for Revision THA Improves Hip Center of Rotation: A Radiographic Evaluation.

BACKGROUND: Bone loss in patients undergoing revision THA poses a considerable challenge for orthopaedic surgeons. Often, to achieve better fixation in remaining bone, larger diameter acetabular components and reaming superiorly may be necessary. However, this is likely to raise the hip center of rotation, which may lead to altered biomechanics, specifically, insufficiency of the abductor muscles, altered gait, and increased risk of dislocation from impingement. More recently, a newer acetabular shell has been designed to more closely replicate the native hip center of rotation in these circumstances while maintaining adequate fixation. QUESTIONS/PURPOSES: The purpose of this study was to compare the radiographic parameters of this newer design with conventional hemispheric cups in revision THA. Specifically, we assessed the differences in (1) vertical center of rotation (COR) displacement and (2) horizontal COR displacement. METHODS: Between January 2016 and April 2016, five reconstructive surgeons at five institutions utilized a newer highly porous acetabular shell designed with peripheral screw holes and vertically eccentric COR to allow for restoration of center of hip rotation in revision THA. We included all patients who received this device. During this time, the general indications at these sites for using the new device included Paprosky Stage IIA, IIB, IIC, or IIIA acetabular defects. This yielded 29 patients who were subsequently matched (one to two) by cup size and sex to a cohort who underwent revision THA with conventional hemispheric cups between January 2015 and May 2016. To determine hip COR, radiographic measurements were performed. A circle contiguous to the acetabulum was drawn and the center was determined as the hip COR. All measurements were made from the interteardrop line for both the revised and native hips. A line through the teardrops was used for all horizontal measurements. Center position adjustments were made based on the manufacturer-specified values. Comparisons were performed using chi-square tests for categorical and t-tests for continuous variables. There was no difference in the severity of bone loss before the revision in the groups, as evidenced by Paprosky staging of preoperative radiographs. RESULTS: The mean vertical COR displacement was smaller in patients who had the novel cup (3.5 mm; range, -12 to 15 mm; mean difference, -7.3 mm; 95% confidence interval [CI], -13.2 to -1.5) as compared with those who had the conventional cup (10.5 mm; range, -4 to 50 mm; mean difference, 7.3 mm; 95% CI, -12.5 to -2.2; p = 0.003). There was no difference in mean horizontal displacement between the two groups (-0.06 ± 6.1 versus 1.7 ± 7.1; mean difference, -1.8; p = 0.903). CONCLUSIONS: Although hip COR was improved based on radiographic measurements with the use of this novel acetabular design, and although this may improve hip biomechanics, more studies are required before its widespread adoption for revision cases of this nature can be recommended. Both implant costs and the risks associated with using a new design in practice will have to be justified by studies that evaluate fixation, clinical function and implant survival, and patient-reported outcome scores, all of which were beyond the scope of this preliminary report. LEVEL OF EVIDENCE: Level III, therapeutic study.

Wound Closure Techniques for Total Knee Arthroplasty: An Evidence-Based Review of the Literature.

BACKGROUND: This literature review is aimed at identifying the different methods for superficial and deep wound closure in total knee arthroplasty and evaluating their outcomes. We evaluated (1) closure time, (2) infection and other complication rates, and (3) local wound-related outcomes. METHODS: A thorough search of the literature was performed using 3 electronic databases. Inclusion criteria included manuscripts that were written in English and available in full-text format. Reports were stratified into those that describe deep closure (7) and those that describe superficial closure (11). RESULTS: In superficial closure, staples may provide the fastest closure, adhesives, lower incidence of superficial complications, and subcuticular suture closures, greatest blood flow. In deep closure, barbed sutures may allow for faster closure time while providing similar postoperative complication rates and outcomes when compared to traditional sutures. The use of barbed sutures has been shown to utilize fewer resources and may potentially lead to a slight reduction in costs. CONCLUSION: Ultimately, no optimal closure technique has been developed, and current studies do not provide a clear evidence-based answer. This field needs much more evidence-based studies before one can draw conclusions. Even though some of these studies are prospective and randomized, they may not be generalizable. Also, many of the studies have small numbers and are subject to type II errors and fragility. Certainly, more studies are needed to truly understand the advantages and disadvantages of these new methods. Nevertheless, this review allows orthopedists to evaluate the differences between closure methods.

Postoperative Pain and Analgesia: Is There a Genetic Basis to the Opioid Crisis?

BACKGROUND: Multiple factors have been implicated in determining why certain patients have increased postoperative pain, with the potential to develop chronic pain. The purpose of this study was to: 1) identify and describe genes that affect postoperative pain perception and control; 2) address modifiable risk factors that result in epigenetic altered responses to pain; and 3) characterize differences in pain sensitivity and thresholds between opioid-naïve and opioid-dependent patients. MATERIALS AND METHODS: Three electronic databases were used to conduct the literature search: Pubmed, EBSCO host, and SCOPUS. A total of 372 abstracts were reviewed, of which 46 studies were deemed relevant and are included in this review. RESULTS: Specific gene alterations that were shown to affect postoperative pain control included single nucleotide polymorphisms in the mu, kappa, and delta opioid receptors, ion channel genes, cytotoxic T-cells, glutamate receptors and cytokine genes, among others. Alcoholism, obesity, and smoking were all linked with genetic polymorphisms that altered pain sensitivity. Opioid abuse was found to be associated with a poorer response to analgesics postoperatively, as well as a risk for prescription overdose. CONCLUSION: Although pain perception has multiple complex influences, the greatest variability seen in response to opioids among postoperative patients known to date can be traced to genetic differences in opioid metabolism. Further study is needed to determine the clinical significance of these genetic associations.

Nerve Decompression Surgery After Total Hip Arthroplasty: What Are the Outcomes?

BACKGROUND: The purpose of our study was to compare (1) muscle strength; (2) pain; (3) sensation; (4) various outcome measurement scales between post-total hip arthroplasty (THA) patients who had a sciatic nerve injury and did or did not receive decompression surgery for this condition; and (5) to compare these findings with current literature. METHODS: Nineteen patients who had nerve injury after THA were reviewed. Patients were stratified into those who had a nerve decompression (n = 12), and those who had not (n = 7). Motor strength was evaluated using the Muscle Strength Testing Scale. Pain was evaluated by using the visual analogue scale. Systematic literature search was performed to compare the findings of this study with others currently published. RESULTS: The decompression group had a significant improvement in motor strength and the visual analog scale scores as compared with nonoperative group. Patients in decompression group had a significant larger increase in the mean Harris hip score and University of California Los Angeles score. There was no significant difference in the increase of Short Form-36 physical and mental scores between the 2 groups. Literature review for nonoperative management yielded 5 studies (93 patients), with 33% improvement. There were 7 studies (81 patients) on nerve decompression surgery, with 75% improvement. CONCLUSION: This study demonstrates the benefits of nerve decompression surgery in patients who had sciatic nerve injury after THA, as evidenced by results of standardized outcome measurement scales. It is possible to achieve improvements in terms of strength, pain, and clinical outcomes. Comparative studies with larger cohorts are needed to fully assess the best candidates for this procedure.

Determining Cost-Effectiveness of Total Hip and Knee Arthroplasty Using the Short Form-6D Utility Measure.

BACKGROUND: With the implementation of the Patient Protection and Affordable Care Act, cost-effectiveness analyses are becoming increasingly important for resource allocation, and particularly for the justification of costly procedures, such as total knee and total hip arthroplasties (TKAs and THAs). Therefore, using the Short Form-6D (SF-6D) utility values, the purpose of this study was to determine (1) the quality-adjusted life years (QALYs) gained and (2) and the cost-effectiveness of undergoing THA and TKA. METHODS: A total of 844 patients (357 men, 487 women) who had a mean age of 65 years (range, 39 to 80 years) underwent primary TKA, and 224 patients who had a mean age of 69 years (range, 44 to 88 years) underwent primary THAs at 7 institutions. The SF-6D values were derived for each patient preoperatively and at 1-year follow-up. QALYs were estimated at 1 year, and lifetime QALYs gained were determined using predicted life-expectancy values, at a discounted rate of 3% per year of life expectancy, to reflect a diminishing gain with time. National-level costs were determined using the 2011 Nationwide Inpatient Sample, and incremental cost-effectiveness ratios (ICER) were deduced for both groups. RESULTS: The preoperative SF-6D values for the THA and TKA cohorts were 0.614 (range, 0.37 to 1) and 0.62 (range, 0.3 to 0.93). Postoperatively, SF-6D values improved significantly at 1 year in both groups. One-year QALYs for TKA and THA were 0.768 and 0.799. Lifetime QALYs gained for the groups were 2.07 and 1.85 (1.39 and 1.34 if discounted at a rate of 3% per year). The estimated ICER for TKA vs baseline presurgery was $43,107 per QALY, and $39,453 per QALY for THA vs baseline presurgery. CONCLUSION: The ICER showed that THA and TKA are cost-effective, compared to the $50,000 USD/QALY threshold for cost-effectiveness, and justify resources allocated to these surgeries. The SF-6D can utilize existing functional outcome data, which makes these cost calculations considerably easier and more feasible for practicing orthopedists.

Short-to-Midterm Outcomes of Revision Total Knee Arthroplasty Patients With a Total Stabilizer Knee System.

BACKGROUND: Revision total knee arthroplasty (TKA) can often be challenging. The use of a new revision system may aid in providing better stability, improved function, fit, and implant longevity. Therefore, we assessed: (1) survivorship, (2) clinical outcomes, (3) postoperative complications, and (4) radiographic outcomes of patients who underwent revision TKA using this system. METHODS: Patients from 2 hospitals who underwent revision TKA using a newer generation revision knee system between June 2008 and December 2013 for component instability or aseptic loosening were included. There were 93 patients, who had a mean age of 65 years (range, 41-84 years), and a mean follow-up of 4 years (range, 2-7 years). Survivorship was assessed using Kaplan-Meier analysis. Radiographic analysis was performed using the new Knee Society Roentgenographic Evaluation and Scoring System. RESULTS: Aseptic survivorship was 96% (95% confidence interval, 6.6-7.3), and all-cause survivorship was 94% (95% confidence interval, 6.4-7.2). There were 2 infections and 4 aseptic loosening cases. The mean Knee Society score was 86 points (range, 38-100 points) and the mean functional Knee Society score was 52 points (range, 15-90 points) at final follow-up. The mean postoperative extension and flexion were 2° (range, 0°-20°) and 106° (range, 20°-130°), respectively. There were 3 medical and 11 surgical complications. Excluding the aseptic and septic failures, there were no progressive radiolucencies or osteolysis at final follow-up. CONCLUSION: At up to 7-year follow-up, this new revision system demonstrated excellent survivorship and good functional outcomes. Future studies should be prospective, comparative, and include larger cohorts for further assessment of this device.

The Effect of Pelvic Tilt and Femoral Head Size on Hip Range-of-Motion to Impingement.

BACKGROUND: About 50%-70% of dislocators have cups placed within so-called "safe zones." It has been postulated that factors such as femoral head size and pelvic tilt, obliquity, or rotation may influence postoperative stability. Therefore, we assessed varying degrees of pelvic tilt and head sizes on the range of motion (ROM) to impingement. METHODS: A hip simulator was used to import models of 10 subjects who performed object pickup, squatting, and low-chair rising. Parameters were set for pelvic tilt, stem version, and the specific motions as defined by the subjects. Femur-to-pelvis relative motions were determined for abduction/adduction, internal/external rotation, and flexion/extension. Varying tilt angles were tested. Thirty-two millimeter and 36-mm head with a standard cup and 42-mm dual mobility cup were tested. Cup orientations for abduction and anteversion combinations were chosen, and computations of minimum clearances or impingement between components were made. RESULTS: The ROM to impingement varied with the different pelvic tilts and femoral head sizes and with the different motions. The larger the head size, the larger the impingement-free ROM. Negative 10° of pelvic tilt led to the largest impingement-free zone, whereas 10° of forward tilt was associated with fewer impingement-free cup anteversion and abduction angle combinations. Variations in pelvic tilt had the greatest influence on object pickup and affected the impingement-free "safe zone." CONCLUSION: Targets for impingement-free motion may be smaller when considering varying pelvic tilts and femoral head sizes, particularly for certain activities, such as object pickup. These findings may indicate the need for more individualized patient planning.

What Influences How Patients Rate Their Hospital Stay After Total Hip Arthroplasty?

PURPOSE: Measuring the effect of operative interventions has been a challenge in orthopaedics. The assessment of patient satisfaction, as measured by the Press Ganey (PG) satisfaction surveys, has gained increasing attention. Our purpose was to determine the factors and patient characteristics that influence patient satisfaction after THA. MATERIALS AND METHODS: The PG database was queried identifying 692 THA patients (November 2009 to January 2015). A multiple regression analysis was conducted. RESULTS: Significant influence was found in communication with nurses (p=<0.001), response time of hospital staff (p=0.001), communication with physicians (p=0.002), and hospital environment (p=0.049). Management of pain and communication about medications were not significant for overall hospital rating. There were no differences between PG scores of patients who did and did not have complications. CONCLUSIONS: Hospital rating was significantly influenced by patients' communication with nurses, response time of hospital staff, and communication with physicians. Recognizing the importance of these elements, can greatly improve patient satisfaction after THA.

What Influences How Patients with Depression Rate Hospital Stay After Total Joint Arthroplasty?

BACKGROUND: Recent healthcare reform has spurred important changes to provider reimbursement. With the implementation of the Value Based Purchasing program, significant weight is placed on patient experience of care. The Press Ganey (PG) survey is currently used by over 10,000 hospitals, as it serves to help optimize patient satisfaction. However, confounding factors, such as clinical depression, are not screened against by PG. Thus, arthroplasty surgeons performing lower extremity total joint arthroplasty (TJA) may have difficulty optimizing patient satisfaction while caring for patients with clinical depression. Therefore, we asked: 1) What Press Ganey elements affect the overall hospital rating in patients who suffer from clinical depression? and 2) Are survey responses different between patients who do and do not have clinical depression? MATERIALS AND METHODS: We queried our institutional PG database for patients who underwent a TJA from November 2009 to January 2015. Our search yielded 1,454 patients, of which 204 suffered from depression and 1,250 did not. Multiple regression analysis was performed to determine the influence (b weight) of selected PG survey domains on overall hospital rating. The weighted mean for domain was also calculated. RESULTS: Multiple regression analyses showed that overall hospital ratings were significantly influenced by communication with nurses (b-weight = 0.881, p< 0.001) in post-TJA patients with depression. The remaining domains were not statistically significant. There were no significant differences in individual PG elements for patients who did and did not have depression. CONCLUSION: Overall patient satisfaction among patients with depression was greatly influenced by communication with nurses. Understanding these challenges may encourage care coordination across disciplines for the management of patients with depression before and after surgery. As a result, this could optimize orthopedic surgery outcomes, but, more importantly, patient health and satisfaction, while reducing costs of care.

The Learning Curve Associated with the Administration of Intra-Articular Liposomal Bupivacaine for Total Knee Arthroplasty: A Pilot Study.

INTRODUCTION: Liposomal bupivacaine is a long-acting, local, injectable anesthetic that is used to potentially mitigate post-operative pain after total knee arthroplasty (TKA). In addition, it may reduce opioid use in the post-operative period and shorten lengths-of-stay (LOS). There have been mixed results in the literature with regards to its efficacy, which raises questions regarding the injection technique used. Therefore, we evaluated the learning curve associated with injection techniques prior to, and after, formal teaching. Specifically, we compared differences in: 1) opioid use; 2) LOS; 3) pain intensity; and 4) discharge disposition in patients who did not receive liposomal bupivacaine (no infiltration cohort), received liposomal bupivacaine with less optimal technique (subpar infiltration), and received liposomal bupivacaine with appropriate technique (optimal infiltration) during their primary TKA. MATERIALS AND METHODS: A 1:1:1 ratio of 54 consecutive cases of patients who had no liposomal bupivacaine infiltration, those who had subpar infiltration, and those who had optimal infiltration were included. To evaluate opioid use, the dosages were obtained and converted to their respective morphine milliequivalents (mEq). The total mEq usage was obtained for the day of surgery through post-operative day (POD) 3. LOS was recorded in days. Pain scores were calculated using the visual analogue scale (VAS), obtained from the first post-operative physical therapy note. Discharge status was recorded as discharged to home or rehabilitation. We used an ANOVA test for continuous and X2-square test for categorical variables. RESULTS: When compared to patients who had no infiltration, patients who had subpar infiltration had significantly lower opioid use on day 0, while patients who had optimal infiltration had lower opioid use on post-operative day (POD) 0 and 3. When comparing techniques, opioid use was lower on day 3 for patients who had optimal, as compared to subpar technique. However, LOS and VAS were not significantly different among the three groups. The rehab discharge rate was lower for patients who had optimal as compared to subpar technique. CONCLUSION: There is a learning curve associated with liposomal bupivacaine use, and incorporating an appropriate technique can markedly affect post-operative outcomes. This should be taken into account when evaluating the potential benefits of this peri-articular injection. It appears that liposomal bupivacaine may decrease opioid use and pain scores when optimal infiltration techniques are used.

Development of an Encompassing Questionnaire for Evaluating the Outcomes Following Total Knee Arthroplasty.

INTRODUCTION: There are many standardized scales and questionnaires used to evaluate TKA patients; however, individually they do not always assess patients adequately. Consequently, many are used in combinations to provide a thorough evaluation. However, this leads to redundancy, confusion, and an excessive patient time-burden. Therefore, the purpose of this study was to develop a usable combined knee questionnaire that combines questions in a non-redundant manner. Specifically, we aimed to: 1) create a combined knee questionnaire that encompasses questions from multiple systems, while eliminating redundancy; 2) correlate the new system with the existing validated questionnaires; and 3) determine the length of time it takes to administer this new questionnaire. MATERIALS AND METHODS: In a previous study, it was determined that the six most commonly cited validated systems to assess the knee were the: Knee Society Score (KSS), The Western Ontario and McMaster Universities Arthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), Lower Extremity Functional Scale (LEFS), Activity Rating Scale (ARS), and Short-Form-36 (SF-36). Therefore, we ensured that the new questionnaire encompassed all elements of these systems. After development of the combined questionnaire, we co-administered it to 20 subjects alongside the above validated questionnaires. We then transposed the corresponding answers from the combined questionnaire to each selected validated system to perform an intra-class correlation analysis. In addition, we recorded the length of time it took to administer the new questionnaire and compared it to the time it took to administer the individual validated questionnaires. RESULTS: Intra-class correlation analysis demonstrated statistically significant positive correlations between the KSS, WOMAC, KOOS, LEFS, ARS, SF-36, and the corresponding questions in the combined questionnaire. The mean length of time it took to administer the combined questionnaire (mean, 10.1 minutes, range, 6.6 to 12.6 minutes) was significantly shorter than the time it took to administer the selected validated questionnaires (mean, 21.3 minutes, range, 17.3 to 24.1 minutes). CONCLUSION: We have proposed an all-encompassing combined knee questionnaire that eliminates redundancy and inefficiency during the evaluation of TKA patients. It is a reliable, time-efficient system that can be utilized to fill out the most commonly used questionnaires for assessing TKA. Standardization and uniform use of this questionnaire may simplify future patient assessment following TKA.

Does Chronic Corticosteroid Use Increase Risks of Readmission, Thromboembolism, and Revision After THA?

BACKGROUND: Systemic corticosteroids are commonly used to treat autoimmune and inflammatory diseases, but they can be associated with various musculoskeletal problems and disorders. There currently is a limited amount of data describing the postoperative complications of THA associated specifically with chronic corticosteroid use. QUESTIONS/PURPOSES: For chronic corticosteroid users undergoing THA, we asked: (1) What is the risk of hospital readmission at 30 and 90 days after surgery? (2) What is the risk of venous thromboembolism at 30 and 90 days after surgery? (3) What is the risk of revision hip arthroplasty at 12 and 24 months after surgery? METHODS: We identified patients in the Statewide Planning and Research Cooperative System who underwent primary THA between January 2003 and December 2010. This database provides hospital discharge abstracts for all admissions in the state of New York each year. We used propensity scores to three-to-one match the 402 chronic corticosteroid users with a comparison cohort of 1206 patients according to age, sex, race, comorbidity score, year of surgery, and hip osteonecrosis. The risk of each outcome was compared between chronic corticosteroid users and the matched cohort. Because multiple comparisons were made, we considered p less than 0.008 as statistically significant. RESULTS: Readmission was more common for corticosteroid users at 30 days (odds ratio [OR], 1.45; 95% CI, 1.14-1.85; p = 0.003) and 90 days (OR, 1.37; 95% CI, 1.09-1.73; p = 0.007). Venous thromboembolism was not more frequent in corticosteroid users at 30 days (OR, 2.39; 95% CI, 1.08-5.26; p = 0.031) or 90 days (OR, 1.91; 95% CI, 1.03-3.53; p = 0.039). Revision arthroplasty was more common in corticosteroid users at 12 months (OR, 2.49; 95% CI, 1.35-4.59; p = 0.004), but not 24 months (OR, 2.04; 95% CI, 1.19-3.50; p = 0.010). CONCLUSIONS: After THA, chronic corticosteroid use is associated with an increased risk of readmission at 30 and 90 days and revision hip arthroplasty at 12 months in corticosteroid users. Patients and providers should discuss these risks before surgery. Insurers should consider incorporating chronic corticosteroid use as a comorbidity in bundled payments for THA, since this patient population is more likely to return to their provider for care during the postoperative period. LEVEL OF EVIDENCE: Level III, therapeutic study.

Low Frequency of Early Complications With Dual-mobility Acetabular Cups in Cementless Primary THA.

BACKGROUND: Dislocation complicates 1% to 5% of primary total hip arthroplasties (THAs). As a result, some surgeons consider dual-mobility articulations, which are usually used in the revision setting to decrease the likelihood of dislocation, as an option for primary THA. However, few studies have evaluated their use in this setting. QUESTIONS/PURPOSES: (1) What is the cup survivorship when the dual-mobility articulation is used in the setting of primary THA? (2) What are the clinical outcomes with this approach? (3) What are the radiographic outcomes? (4) What are the complications of dual-mobility articulations in primary THA? METHODS: Between 2011 and 2013, the five participating surgeons performed 495 cementless primary THAs. During that time, one of the five surgeons used dual-mobility articulations for all THAs, and the other four used it whenever the acetabular cup size was 52 mm or greater to enable a 28-mm head. Of the 495 patients, 453 (92%) were performed using this device. Smaller patients were treated with a standard THA. Of the 453 patients, a total of 43 patients (10%) were lost to followup before the 2-year minimum. The resulting 410 patients who were included in the analysis (164 men, 246 women) had a mean age of 64 years (SD, 12 years). The mean followup was 3 years (SD, 0.7 years). We performed Kaplan-Meier analyses to assess survivorship to aseptic failure and all-cause acetabular component survivorship. Clinical outcomes were evaluated using the Harris hip score (HHS); radiographs were assessed for cup migration, progressive radiolucencies, and positional changes of the components; and any surgery-related complications were recorded. RESULTS: The survivorship to aseptic failure and all-cause acetabular component survivorship was 99.8% (failures, n = 1) (95% confidence interval [CI], 4.517-4.547) and 99.3% (failures, aseptic, n = 1; septic, n = 2) (95% CI, 4.494-4.543); one hip had trunnion notching caused by impingement of a malpositioned cup, which was treated with revision of the cup and stem; and two patients had periprosthetic infections that were treated with two-stage revisions. There were no dislocations. Patients had a mean HHS of 94 (SD, 6) at final followup. On radiographic evaluation, no progressive radiolucencies or positional changes of the components were identified. Surgical complications included one traumatic avulsion of the abductors, one traumatic avulsion of the greater trochanter, which was repaired without revision of any of the components, and one loose femoral stem, which required revision of the femoral component only. CONCLUSIONS: Dual-mobility cups in primary THA yield seemingly comparable survivorship and complications to conventional THA bearings at short-term followup. Because serious complications have occasionally been reported with the use of these bearings, larger, longer term, comparative-and ideally, randomized-trials will be needed to establish the superiority of one approach over the other. Until or unless such studies show the superiority of dual-mobility designs for primary THA, we recommend that in the setting of uncomplicated primary THA, dual-mobility articulations be used only in centers that track their results carefully or in research protocols. LEVEL OF EVIDENCE: Level IV, therapeutic study.

A Randomized, Clinical Trial of Preadmission Chlorhexidine Skin Preparation for Lower Extremity Total Joint Arthroplasty.

BACKGROUND: Periprosthetic infections are devastating postoperative complications of total joint arthroplasty (TJA), with native skin flora commonly identified as causative organisms. We compared 2% chlorhexidine gluconate-impregnated cloths to standard-of-care antiseptic bathing in patients before TJA, to evaluate periprosthetic infection risk at 1-year follow-up. METHODS: This was a prospective, randomized, controlled trial at a single institution of patients undergoing hip or knee arthroplasty. Chlorhexidine-treated patients (275 arthroplasties) applied 2% chlorhexidine gluconate-impregnated cloths the night before and morning of admission. The standard-of-care cohort (279 arthroplasties) bathed with soap and water preadmission. Patients were excluded according to the following: (1) unable to comply with study requirements, (2) pregnant, (3) <18 years, (4) medical history of immunosuppression or steroid use, (5) chronic hepatitis B/C infection, (6) had infection around joint requiring surgery, or (7) chose not to participate. A total of 539 patients (554 arthroplasties) were included in the final population. There were no significant differences in American Society of Anesthesiologists grade, cut time, risk scores, or diabetes and smoking prevalence between cohorts (P > .05). RESULTS: A lower periprosthetic infection rate was found in the chlorhexidine cohort (0.4%) when compared to standard-of-care cohorts (2.9%). The infection odds ratio was 8.15 (95% confidence interval = 1.01-65.6; P = .049) for the standard-of-care cohort compared to the chlorhexidine cohort. No differences in assessed risk factors were found between groups. No severe adverse events were observed. CONCLUSIONS: Preoperative chlorhexidine cloth use decreased the risk of periprosthetic infection. This may be an appropriate antiseptic protocol to implement for patients undergoing lower extremity TJA.

Acetabular Cup Anteversion and Inclination in Hip Range of Motion to Impingement.

BACKGROUND: It is advocated that to avoid complications associated with femoral stem impingement, acetabular positioning should be within a "safe zone." However, instability remains prevalent despite accurate cup positioning, with studies showing dislocations of cups despite positioning within safe zones. We assessed cup position angles associated with impingement in a group of subjects during (1) squatting; (2) object pick-up; and (3) low chair rise. METHODS: Ten subjects (mean age, 69 years; body mass index, 28.4 kg/m(2)) performed object pick up, squatting, and low-chair rising. Femur-to-pelvis relative motions were recorded for flexion/extension, abduction/adduction, and internal/external rotation. A previously reported custom-validated hip range-of-motion 3-dimensional simulator was used, set for neutral pelvic tilt and 15(°) of stem version. Acetabular cup abduction and anteversion combinations were chosen. The software computed minimum clearances between components for any hip position. An idealized tapered wedge stem with a 132° neck angle and a 36-mm femoral head was used. RESULTS: Eight subjects had impingement on squatting between 21(°) and 51(°) of inclination. During object pick-up, 9 subjects had impingement with inclination and anteversion angles within the "safe zone." In low-chair rise, 8 subjects had impingement at cup inclination angles between 14.5(°) and 49.5(°). CONCLUSION: The true acetabular target for impingement-avoidance motion is much smaller than previously believed and varies considerably between patients. Certain activities, such as picking up an object, low-chair rise, and squatting reduce the size of the safe zone. This study supports the need for better individualized preoperative patient-specific planning and intraoperative execution for placement of the components.

Histopathological Evaluation of the Anterior Cruciate Ligament in Patients Undergoing Primary Total Knee Arthroplasty.

This study assessed gross and histopathological ACL changes in arthritic knees (n=174) undergoing total knee arthroplasty. Histopathological changes were assessed and graded as absent (0), mild (1), moderate (2), or marked (3). These were correlated to demographic and clinical factors, and radiographic evaluations. The ACL was intact in 43, frayed in 85, torn in 15, and absent in 31 knees. Eighty-five percent had histological changes. Overall, there were significant associations between greater age and BMI, and histological changes. Grade IV knees had significantly greater calcium pyrophosphate deposits, microcyst formation, and number of pathologic changes. These correlations may aid decision-making when determining suitability for unicompartmental or bicruciate-retaining arthroplasties, though further studies should correlate these histological findings to mechanical and functional knee status.

Does Hemophilia Increase the Risk of Postoperative Blood Transfusion After Lower Extremity Total Joint Arthroplasty?

BACKGROUND: Hemophilia can lead to the development of arthropathies secondary to recurrent hemarthroses. However, given these patients' bleeding tendencies, postoperative complications associated with blood loss are a considerable concern. METHODS: We identified men in the Nationwide Inpatient Sample who underwent total hip or knee arthroplasty between January 1998 and December 2010. We used propensity scores to match 332 hemophiliacs (267 hemophilia A, 65 hemophilia B) to a comparison cohort of 996 patients in a 1:3 ratio, according to the site of arthroplasty, year of admission, age, race, and Charlson and Deyo score. RESULTS: The incidence of any postoperative transfusion was 15.06% for hemophiliacs, compared with 9.84% for the matched comparison cohort (P = .012). For hemophiliacs, the odds ratio was 1.60 (95% confidence interval [CI] = 1.11-2.31; P = .013) for any transfusion, 1.90 (95% CI = 1.24-2.92; P = .003) for allogenic transfusion, and 1.05 (95% CI = 0.56-1.95; P = .888) for autogenic transfusion. CONCLUSION: Hemophilia is associated with an increased risk of blood transfusion after lower extremity total joint arthroplasty. Patients and providers should discuss these risks before surgery, and insurers should consider incorporating this comorbidity into bundled payments for total hip and knee arthroplasty.

How to Approach a Recalled Dual Modular Hip Implant: An Update.

BACKGROUND: The aim of this study was to provide an update on the "Modular taper junction corrosion and failure: how to approach a recalled total hip arthroplasty implant" (Pivec et al JOA 2014) publication. METHODS: We performed a comprehensive review of the literature in English, with search terms referencing to the diagnosis, management, and outcomes of patients who underwent total hip arthroplasty with a recalled dual modular hip implant. RESULTS: Based on this review and the new guidelines by the American Academy of Orthopedic Surgeons and the Hip Society, we propose an updated algorithm for the diagnosis and management of patients with these recalled implants. CONCLUSION: When encountering patients with these prostheses, it is imperative to take a step-by-step approach to evaluate whether patients are having potential complications. We hope that this has further clarified the appropriate steps that need to be carried out when confronted with these recalled devices.

Bilateral Symmetrical Comparison of Femoral and Tibial Anatomic Features.

BACKGROUND: Variability in morphologic features of the human lower extremity within and across populations has been reported, but limb asymmetry within individuals is often overlooked. For example, in 19 studies of version of the lower extremity in the literature, 6 document asymmetry in the population, but none of these reports document asymmetry in an individual. The aim of this study was to identify the (a)symmetry and quantify variability in the tibiae and femora of matched pairs of limbs. More specifically, using a computed tomography scan database tool, we (1) identified (a)symmetry between paired left and right legs for angulation, version, and alignment features and (2) calculated the percentage of paired limbs with >1° of (a)symmetry for each evaluated parameter. METHODS: Computerized axial tomographic scans (<1.0 mm slices) from bilateral lower limbs of 361 skeletally mature subjects without bone pathology were prospectively acquired. Bones were segmented and morphologic features were measured. RESULTS: Angular features are symmetric left to right, but rotational features are not, with 7° of mean asymmetry in femoral anteversion (range: 0°-23°) and 3° of asymmetry in tibial version (range: 0°-8°). CONCLUSIONS: This study disproves the hypothesis that human limbs are absolutely symmetric, confirming instead that there is asymmetry in version between left and right paired limbs. Surgeons strive for symmetry in lower extremity reconstruction, and they often compare side to side in outcome studies, believing that normal limbs are absolutely symmetric when this is not necessarily true. These assumptions concerning lower extremity symmetry need to be reassessed.

Can We Really "Feel" a Balanced Total Knee Arthroplasty?

BACKGROUND: Balancing techniques in total knee arthroplasty are often based on surgeons' subjective judgment. However, newer technologies have allowed for objective measurements of soft tissue balancing. This study compared the use of sensor technology to the 30-year surgeon experience regarding (1) compartment loads, (2) soft tissue releases, and (3) component rotational alignments. METHODS: Patients received either sensor-guided soft tissue balancing (n = 10) or manual gap balancing (n = 12). Wireless, intraoperative sensor tibial inserts were used to measure intracompartmental loads. The surgeon was blinded to values in the manual gap-balancing cohort. In the sensor cohort, the surgeon was unblinded, and implant trials were placed after normal releases were performed to guide further ligament releases after femoral and tibial resections, as needed. Load measurements were taken at 10°, 45°, and 90°. RESULTS: The sensor cohort had lower medial and lateral compartment loading at 10°, 45°, and 90°. The sensor group had lower mean differences in intercompartment loading at 10° (-5.6 vs -51.7 lbs), 45° (-9.8 vs -45.9 lbs), and 90° (-4.3 vs -27 lbs) compared to manually balanced patients. There were 10 additional soft tissue releases in the sensor cohort (2 initial ones before sensor use), compared to 2 releases in the gap-balanced cohort. In the gap-balanced cohort, tibial trays were positioned at a mean 9° external rotation, compared to a mean 1° internal rotation in the sensor-guided cohort. CONCLUSION: Sensor-balanced total knee arthroplasties provide objective feedback to perform releases and potentially improve knee balancing and rotational alignment. Future work may clarify whether these changes are beneficial for our patients.