Preoperative Pain Catastrophizing and Neuropathic Pain Do Not Predict Length of Stay and Early Post-Operative Complications following Total Joint Arthroplasty.

BACKGROUND: Both pain catastrophizing and neuropathic pain have been suggested as prospective risk factors for poor postoperative pain outcomes in total joint arthroplasty (TJA). OBJECTIVE: We hypothesized that pain catastrophizers, as well as patients with pain characterized as neuropathic, would exhibit higher pain scores, higher early complication rates and longer lengths of stay following primary TJA. METHODS: A prospective, observational study in a single academic institution included 100 patients with end-stage hip or knee osteoarthritis scheduled for TJA. In pre-surgery, measures of health status, socio-demographics, opioid use, neuropathic pain (PainDETECT), pain catastrophizing (PCS), pain at rest and pain during activity (WOMAC pain items) were collected. The primary outcome measure was the length of stay (LOS) and secondary measures were the discharge destinations, early postoperative complications, readmissions, visual analog scale (VAS) levels and distances walked during the hospital stay. RESULTS: The prevalence of pain catastrophizing (PCS ≥ 30) and neuropathic pain (PainDETECT ≥ 19) was 45% and 20.4%, respectively. Preoperative PCS correlated positively with PainDETECT (rs = 0.501, p = 0.001). The WOMAC positively correlated more strongly with PCS (rs = 0.512 p = 0.01) than with PainDETECT (rs = 0.329 p = 0.038). Neither PCS nor PainDETECT correlated with the LOS. Using multivariate regression analysis, a history of chronic pain medication use was found to predict early postoperative complications (OR 38.1, p = 0.47, CI 1.047-1386.1). There were no differences in the remaining secondary outcomes. CONCLUSIONS: Both PCS and PainDETECT were found to be poor predictors of postoperative pain, LOS and other immediate postoperative outcomes following TJA.

Metric Selection, Metric Targets, and Risk Adjustment Should be Considered in the Design of Gainsharing Models for Bundled Payment Programs in Total Joint Arthroplasty.

BACKGROUND: Under bundled payment models, gainsharing presents an important mechanism to ensure engagement and reward innovation. We hypothesized that metric selection, metric targets, and risk adjustment would impact surgeons' performance in gainsharing models. METHODS: Patients undergoing total joint arthroplasty at an urban health system from 2017 to September 2018 were included. Gainsharing metrics included the following: length of stay, % discharge-to-home, 90-day readmission rate, % of patients with episode spend under target price, and % of patients with patient-reported outcomes (PROs) collected. Four scenarios were created to evaluate how metric selection/adjustment impacted surgeons' performance designation: scenario 1 used "aspirational targets" (>60th percentile), scenario 2 used "acceptable targets" (>50th percentile), scenario 3 risk-adjusted surgeon performance prior to comparing aspirational targets, and scenario 4 included a PRO collection metric. Number of metrics achieved determined performance tier, with higher tiers getting a greater share of the gainsharing pool. RESULTS: In total, 2776 patients treated by 12 surgeons met inclusion criteria (mean length of stay 3.0 days, readmission rate 4.0%, discharge-to-home 74%, episode spend under target price 85%, PRO collection 56%). Lowering of metric targets (scenario 1 vs. 2) resulted in a 75% increase in the number of high performers and 98% of the gainsharing pool being eligible for distribution. Risk adjustment (scenario 3) caused 50% of providers to move to higher performance tiers and potential payments to increase by 28%. Adding the PRO metric did not change performance. CONCLUSION: Quality metric/target selection and risk adjustment profoundly impact surgeons' performance in gainsharing contracts. This impacts how successful these contracts can be in driving innovation and dis-incentivizing the "cherry picking" of patients. LEVEL OF EVIDENCE: Level III.

Defining and Optimizing Value in Total Joint Arthroplasty From the Patient, Payer, and Provider Perspectives.

BACKGROUND: The purpose of this study is to define value in bundled total joint arthroplasty (TJA) from the differing perspectives of the patient, payer/employer, and hospital/provider. METHODS: Demographic, psychosocial, clinical, financial, and patient-reported outcomes (PROs) data from 2017 to 2018 elective TJA cases at a multihospital academic health system were queried. Value was defined as improvement in PROs (preoperatively to 1 year postoperatively) for patients, improvement in PROs per $1000 of bundle cost for payers, and the normalized sum of improvement in PROs and hospital bundle margin for providers. Bivariate analysis was used to compare high value vs low value (>50th percentile vs <50th percentile). Multivariate analysis was performed to identify predictors. RESULTS: A total of 280 patients had PRO data, of which 71 had Medicare claims data. Diabetes (odds ratio [OR], 0.45; P = .02) predicted low value for patients; female gender (OR, 0.25), hypertension (OR, 0.17), pulmonary disease (OR, 0.12), and skilled nursing facility discharge (OR, 0.17) for payers (P ≤ .03 for all); and pulmonary disease (OR, 0.16) and skilled nursing facility discharge (OR, 0.19) for providers (P ≤ .04 for all). CONCLUSION: This is the first article to define value in TJA under a bundle payment model from multiple perspectives, providing a foundation for future studies analyzing value-based TJA.

Are Histological Examinations of Arthroplasty Specimens Performed Consistently Across the Country? A Large Database Study.

BACKGROUND: It is currently unknown to what extent routine histological examination of joint arthroplasty specimens occurs across hospitals nationwide. Although this practice is neither supported nor refuted by the available evidence, given the increasing demand for joint arthroplasties, it is crucial to study overall utilization as well as its main drivers. QUESTIONS/PURPOSES: Using national data on joint replacements, we aimed to evaluate: (1) What is the current use of routine histological examination of joint arthroplasty specimens? (2) Does the use vary by geographic location and hospital characteristics? (3) Has use changed over time? METHODS: From the Premier Healthcare database (2006-2016) we included claims data from 87,667 shoulder (595 hospitals, median age 70 years, 16% nonwhite), 564,577 hip (629 hospitals, median age 65 years, 21% nonwhite), and 1,131,323 (630 hospitals, median age 66 years, 24% nonwhite) knee arthroplasties (all elective). Our study group has extensive experience with this data set, which contains information on 20% to 25% of all US hospitalizations. Included hospitals are mainly concentrated in the South (approximately 40%) with equal distributions among the Northeast, West, and Midwest (approximately 20% each). Moreover, the Premier data set has detailed billing information, which allows for evaluations of real-world clinical practice. There was no missing information on the main variables of interest for this specific study. We assessed frequency of histology examination (defined by Current Procedural Terminology codes) overall as well as by hospital characteristics (urban/rural, bed size, teaching status, arthroplasty volume), geographic region (Northeast, South, Midwest, West), and year. Given the large sample size, instead of p values, standardized differences were applied in assessing group differences where a standardized difference of > 0.1 (or 10%) was assumed to represent a meaningful difference between groups. For significance of trends, p values were applied. Percentages provided represent proportions of individual procedures. RESULTS: In most hospitals, histology testing was either rare (1%-10%, used in 187 of 595, 189 of 629, and 254 of 630 hospitals) or ubiquitous (91%-100%, used in 121 of 595, 220 of 629, and 195 of 630 hospitals) for shoulder, hip, and knee arthroplasties, respectively. Overall, histology testing occurred more often in smaller hospitals (37%-53% compared with 26%-45% in larger hospitals) and those located in the Northeast (59%-68% compared with 22%-44% in other regions) and urban areas (32%-49% compared with 20%-31% in rural areas), all with standardized differences > 10%. Histologic examination is slowly decreasing over time: from 2006 to 2016, it decreased from 34% to 30% for shoulder arthroplasty, from 50% to 45% for THAs, and from 43% to 38% for TKAs (all p < 0.001). CONCLUSIONS: Although overall use is decreasing, a substantial number of hospitals still routinely perform histology testing of arthroplasty specimens. Moreover, variation between regions and hospital types suggests that this practice is driven by a variety of factors. This is the first study addressing national utilization, which will be helpful for individual hospitals to assess how they compare with national utilization patterns. Moreover, the findings have clear implications for followup studies, which may be necessary given the exponentially growing demand for arthroplasties. LEVEL OF EVIDENCE: Level III, therapeutic study.

Robotic-assisted versus standard unicompartmental knee arthroplasty-evaluation of manuscript conflict of interests, funding, scientific quality and bibliometrics.

PURPOSE: Robotic-assisted unicompartmental knee arthroplasty (UKA) has gained popularity over the last decade claiming enhanced surgical precision and better joint kinematics, with peer-reviewed publications about this new technology also increasing over the past few years. The purpose of our study was to compare manuscripts about robotic-assisted UKA to those about standard UKA in terms of industry funding, author conflict of interest, scientific quality, and bibliometrics. METHODS: A systematic search using PRISMA guidelines on PubMed and Google Scholar from 2012 to 2016 resulted in 45 papers where robotic technology was performed for UKA and 167 papers that UKA were performed without the assistance of a robot. Between the two groups, we compared (1) rate of manuscripts with reported conflict of interest or industry funding, (2) journal impact factor, (3) level of evidence, and (4) relative citation ratio. RESULTS: Fifty-one percent (23/45) of robotic UKA manuscripts were industry-funded or had authors with financial conflict of interest, compared to 29% ([49/167], p < 0.01) of non-robotic UKA papers. Significantly more robotic UKA papers (24% [11/45] vs 9% [16/167), p < 0.01) were published in journals that were not assigned an impact factor by the Journal Citations Report. There was no difference in regard to bibliometrics or level of evidence. CONCLUSION: Manuscripts in which UKA was performed with the assistance of a robot were more likely to be industry funded or be written by authors with financial conflicts of interest and published in less prestigious journals. There were no differences in scientific quality or influence between the two groups. Readers analyzing published data should be aware of the potential conflicts of interests in order to more accurately interpret manuscripts data and conclusions.

Risk Factors for Staphylococcus aureus Nasal Colonization in Joint Arthroplasty Patients.

BACKGROUND: Several studies have shown that Staphylococcus aureus (S aureus) nasal colonization is associated with surgical site infection and that preoperative decolonization can reduce infection rates. Up to 30% of joint arthroplasty patients have positive S aureus nasal swabs. Patient risk factors for colonization remain largely unknown. The aim of this study was to determine whether there is a specific patient population at increased risk of S aureus nasal colonization. METHODS: This study is a retrospective review of 716 patients undergoing hip or knee arthroplasty beginning in 2011. All patients were screened preoperatively for nasal colonization. Univariate and multivariate analyses were used to assess risk factors for nasal colonization. RESULTS: A total of 716 patients undergoing joint arthroplasty had preoperative nasal screening. One hundred twenty-five (17.50%) nasal swabs were positive for methicillin-susceptible S aureus (MSSA), 13 (1.80%) were positive for methicillin-resistant S aureus (MRSA), and 84 (11.70%) were positive for other organisms. In bivariate analysis, diabetes (P = .04), renal insufficiency (P = .03), and immunosuppression (P = .02) were predictors of nasal colonization with MSSA/MRSA. In multivariate analysis, immunosuppression (P = .04; odds ratio, 2.0; 95% confidence interval, 1.03-3.71) and renal insufficiency (P = .04; odds ratio, 2.5; 95% confidence interval, 1.01-6.18) were independent predictors of nasal colonization with MSSA/MRSA. CONCLUSION: Overall, 17.5% of patients undergoing primary hip or knee arthroplasty screened positive for S aureus. Diabetes, renal insufficiency, and immunosuppression are risk factors for such colonization. Given that these comorbidities are already known independent risk factors for periprosthetic joint infection, these patients should be particularly screened and when necessary, decolonized.

The Effect of Door Opening on Positive Pressure and Airflow in Operating Rooms.

INTRODUCTION: Door openings and increased foot traffic in operating rooms (ORs) during total joint arthroplasty are thought to increase the risk of surgical site infection. METHODS: Digital manometers were used to collect pressure data during off-hours at the thresholds of both the outer door (ie, the door to the common OR hallway) and the inner substerile door, which opens to the substerile hallway, of six empty ORs used for total joint arthroplasty. Airflow patterns were visualized with smoke studies to determine whether outside air entered the ORs during single or multiple door openings. Data were analyzed using the Student t-test and one-way analysis of variance. RESULTS: Positive pressure was not defeated during any door-opening event. The average time for recovery of the initial pressurization in the OR regardless of the door used was between 14 and 15 seconds (P = 0.462). No differences in the degree of room depressurization were noted between entry of personnel through the outer door, passing of a surgical tray through the outer door, and entry of personnel through the inner door (P = 0.312). Smoke studies confirmed that no contaminated outside air entered the OR with single door opening. Outside air entered the OR if two doors were open simultaneously. CONCLUSION: Single door opening does not defeat OR positive pressure, but simultaneous opening of two doors allows contaminated air to flow into the OR. OR traffic should continue to be limited during surgical procedures. OR personnel should be educated about the danger to the sterile field that can result from simultaneous door openings and should be discouraged from such activity.

Trochanteric Bursitis Following Primary Total Hip Arthroplasty: Incidence, Predictors, and Treatment.

BACKGROUND: Trochanteric bursitis (TB) remains a common complication after total hip arthroplasty (THA), with an incidence between 3% and 17%, depending on the surgical approach, with the posterior approach (PA) being relatively protective compared to the lateral approach. The purposes of this study were to determine the incidence of TB after primary THA, identify potential risk factors for TB, and examine the utility of different modes of treatment. METHODS: Retrospective cohort data of 990 primary THAs performed in a single institution, including 613 PAs and 377 direct anterior approaches (DAAs), were analyzed. Data abstracted included demographic data, operative diagnosis, comorbidities, radiographic assessment, and other specific predictors of interest that were compared between patients diagnosed with TB following THA and controls. RESULTS: The incidence of TB following primary THA was 5.4% (54/990) for the entire cohort. The incidence did not differ significantly between the PA and DAA (5% vs 6.1%, respectively; P = .47). Charlson comorbidity index and American Society of Anesthesiology did not differ significantly in the TB group. Lumbar spinal stenosis and history of past smoking were significantly more common in patients who developed TB (P = .03, P = .01, respectively), but did not continue to be significant risk factors on multivariate analysis. All patients were treated nonoperatively by the time of final follow-up. Seventy-four percent required a local steroid injection and 30% required treatment with more than one modality. CONCLUSION: The occurrence of TB is not influenced by the surgical approach (PA or DAA), and could not be predicted by specific comorbidities or radiographic measurements. However, it can be effectively treated conservatively in most cases.

Novel technique for intraoperative sciatic nerve assessment in complex primary total hip arthroplasty: a pilot study.

INTRODUCTION: Sciatic nerve injury (SNI) is a potentially devastating complication after total hip arthroplasty (THA). Intraoperative neural monitoring has been found in several studies to be useful in preventing SNI, but can be difficult to implement. In this study, we examine the results of using a handheld nerve stimulator for intraoperative sciatic nerve (SN) monitoring during complex THA requiring limb lengthening and/or significant manipulation of the SN. METHODS: A consecutive series of 11 cases (9 patients, 11 hips) with either severe developmental dysplasia of the hip (Crowe 3-4) or other underlying conditions requiring complex hip reconstruction involving significant leg lengthening and/or nerve manipulation. SN function was monitored intraoperatively by obtaining pre- and post-reduction thresholds during component trialing. The results of nerve stimulation were then used to influence intraoperative decision-making. RESULTS: No permanent postoperative SN complications occurred, with an average increase of 28.5 mm in limb length, range (6-51 mm). In 2 out of 11 cases, a change in nerve response was identified after trial reduction, which resulted in an alternate surgical plan (femoral shortening osteotomy and downsizing femoral head). In the remaining cases, the stimulator demonstrated a response consistent with the baseline assessment, assuring that the appropriate lengthening was achieved without SNI. 1 patient had a transient motor and sensory peroneal nerve palsy, which resolved within 2 weeks. CONCLUSIONS: The intraoperative use of a handheld nerve stimulator facilitates surgical decision-making and can potentially prevent SNI. The real-time assessment of nerve function allows immediate corrective action to be taken before nerve injury occurs.

Lawsuits After Primary and Revision Total Knee Arthroplasty: A Malpractice Claims Analysis.

INTRODUCTION: As the number of total knee arthroplasties (TKAs) increases, the number of associated complications will also increase. Our goal with this study was to identify common causes of and financial trends relating to malpractice claims filed after TKA. METHODS: We analyzed malpractice claims filed for alleged neglectful primary and revision TKA surgeries performed between 1982 and 2012 by orthopaedic surgeons insured by a large New York state malpractice carrier. RESULTS: We identified 69 primary and 8 revision TKAs in the malpractice carrier's database. All cases were performed between 1982 and 2012; all claims were closed between 1989-2015. The most frequent factor leading to lawsuits for primary TKA was chronic pain or dissatisfaction in 12 cases, followed by nerve palsy in 8, postoperative in-hospital falls in 5, and deep vein thrombosis or pulmonary embolism in 3. Medical complications included acute respiratory distress syndrome, cardiac arrest, and decubitus ulcers. Contracture was most common after revision TKA (three of eight cases). Mean indemnity was $325,369, and the largest single settlement was $2.42 million. The average expense relating to the defense of these cases was $66,365. CONCLUSIONS: Orthopaedic surgeons should continue to focus attention on prevention of complications and on preoperative patient education. Preoperative counseling regarding the risks of incomplete pain relief could reduce substantially the number of suits relating to primary TKAs.

Lawsuits After Primary and Revision Total Hip Arthroplasties: A Malpractice Claims Analysis.

BACKGROUND: As the prevalence of total hip arthroplasty (THA) expands, so too will complications and patient dissatisfaction. The goal of this study was to identify the common etiologies of malpractice suits and costs of claims after primary and revision THAs. METHODS: Analysis of 115 malpractice claims filed for alleged neglectful primary and revision THA surgeries by orthopedic surgeons insured by a large New York state malpractice carrier between 1983 and 2011. RESULTS: The incidence of malpractice claims filed for negligent THA procedures is only 0.15% per year in our population. In primary cases, nerve injury ("foot drop") was the most frequent allegation with 27 claims. Negligent surgery causing dislocation was alleged in 18 and leg length discrepancy in 14. Medical complications were also reported, including 3 thromboembolic events and 6 deaths. In revision cases, dislocation and infection were the most common source of suits. The average indemnity payment was $386,153 and the largest single settlement was $4.1 million for an arterial injury resulting in amputation after a primary hip replacement. The average litigation cost to the insurer was $61,833. CONCLUSION: Nerve injury, dislocation, and leg length discrepancy are the most common reason for malpractice after primary THA. Orthopedic surgeons should continue to focus on minimizing the occurrence of these complications while adequately incorporating details about the risks and limitations of surgery into their preoperative education.

The Accuracy of Digital Templating for Primary Total Hip Arthroplasty: Is There a Difference Between Direct Anterior and Posterior Approaches?

BACKGROUND: The direct anterior approach (DAA) has gained recent popularity for total hip arthroplasty (THA), as it provides immediate feedback on cup position and limb length using fluoroscopy. The purpose of this study is to evaluate any differences in the accuracy of digital templating for preoperative planning of THA, performed with 2 different surgical approaches: DAA using a radiolucent table with intraoperative fluoroscopy and the posterior approach (PA). METHODS: One hundred thirty-one consecutive patients (148 hips) underwent a THA by a single surgeon, using the same cup and stem designs. Seventy-five hips were performed using the DAA using a fracture table and fluoroscopy. Seventy-three hips were performed using the PA with the patient positioned in lateral decubitus using standard positioners without fluoroscopy. Preoperative radiographs were digitally templated by the same surgeon. RESULTS: The PA patients had a higher mean body mass index and were more likely to have a preoperative diagnosis of avascular necrosis. The accuracy of templating for predicting the cup size to be within 2 mm was 91% for DAA vs 88% for PA (P = .61). For stem size, the accuracy was 85% (to within 1 size) for the DAA vs 77% for the PA (P = .71). Likewise, there was no significant difference in predicting the final stem's neck angle or femoral offset. CONCLUSION: Digital templating was found to be a reliable and highly accurate method for predicting component sizes and offset for THA, regardless of using either the PA or the DAA with fluoroscopy.

Day of Surgery and Surgical Start Time Affect Hospital Length of Stay After Total Hip Arthroplasty.

BACKGROUND: The United States spends $12 billion each year on ∼332,000 total hip arthroplasty (THA) procedures with the postoperative period accounting for ∼40% of costs. The purpose of this study was to evaluate the effect of surgical scheduling (day of week and start time) on clinical outcomes, hospital length of stay (LOS), and rate of nonhome discharge in THA patients. METHODS: Analysis of perioperative variables was performed for patients who underwent THA at an urban tertiary care teaching hospital from 2009 to 2014. RESULTS: A total of 580 THA patients were included for analysis. LOS was higher for the Thursday/Friday cohort compared to Monday/Tuesday (3.7 vs 3.4 days; P = .03). Patients who had a surgical start time after 2 PM had longer LOS compared to patients operated on before 2 PM (3.9 vs 3.5 days; P = .03). After controlling for patient comorbidities and THA surgical approach (direct anterior vs posterior), Thursday/Friday THAs were associated with a 3.27 times risk of extended LOS (>75th percentile LOS) compared to Monday/Tuesday THAs (P < .001). Additionally, case start before 2 PM was protective and associated with a 0.46 times odds of extended LOS (P = .01). LOS reduction opportunity for changing surgical start time to before 2 PM was 0.9 days for high-risk patients (American Society of Anesthesiology class 3/4 and/or liver disease) and 0.2 days for low-risk patients (American Society of Anesthesiology class 1/2). CONCLUSION: Patients who underwent THA Thursday/Friday or had start times after 2 PM had significantly extended hospital LOS. Preoperative risk modification along with adjustments to surgical scheduling and/or perioperative staffing may reduce LOS and thus hospital expenditures for THA procedures.

Computer-assisted total knee arthroplasty marketing and patient education: an evaluation of quality, content and accuracy of related websites.

BACKGROUND: The internet is increasingly being used as a resource for health-related information by the general public. We sought to establish the authorship, content and accuracy of the information available online regarding computer-assisted total knee arthroplasty (CA-TKA). METHODS: One hundred fifty search results from three leading search engines available online (Google, Yahoo!, Bing) from ten different countries worldwide were reviewed. RESULTS: While private physicians/groups authored 50.7 % of the websites, only 17.3 % were authored by a hospital/university. As compared to traditional TKA, 59.3 % of the websites claimed that navigated TKA offers better longevity, 46.6 % claimed accelerated recovery and 26 % claimed fewer complications. Only 11.3 % mentioned the prolonged operating room time required, and only 15.3 % noted the current lack of long-term evidence in support of this technology. CONCLUSIONS: Patients seeking information regarding CA-TKA through the major search engines are likely to encounter websites presenting a narrow, unscientific, viewpoint of the present technology, putting emphasis on unsubstantiated benefits while disregarding potential drawbacks. LEVEL OF EVIDENCE: Survey of Materials-Internet.

Safety of Tourniquet Use in Total Knee Arthroplasty in Patients With Radiographic Evidence of Vascular Calcifications.

Tourniquets are often used in total knee arthroplasty (TKA) to improve visualization of structures, shorten operative time, reduce intraoperative bleeding, and improve cementing technique. Despite these advantages, controversy remains regarding the safety of tourniquet use. Tourniquets have been associated with nerve palsies, vascular injury, and muscle damage. Some have hypothesized they may also cause deep vein thrombosis. Last, increased incidence of postoperative wound complications has been reported with use of tourniquets. We conducted a retrospective cohort study to determine whether tourniquet use in TKA in patients with preexisting radiographic evidence of vascular disease increases the risk for wound complications or venous thromboembolism (VTE). Patients (N = 373) were placed in 2 groups: One had no preoperative radiographic evidence of knee arterial calcification (n = 285), and the other had arterial calcifications (n = 88). Overall, arterial calcification did not increase the risk for wound complication or VTE (P > .05). Furthermore, location of arterial calcification did not affect risk for wound complication or VTE. There were no arterial injuries. Diabetes, hypertension, prior VTE, coronary artery disease, and male sex were linked to higher wound complication rates (P < .05). Patients who have preoperative radiographic evidence of arterial calcification can safely undergo tourniquet-assisted TKA.

Prevalence of modifiable surgical site infection risk factors in hip and knee joint arthroplasty patients at an urban academic hospital.

Surgical site infections after hip and knee arthroplasty can be devastating if they lead to periprosthetic joint infection. We examined the prevalence of the modifiable risk factors for surgical site infection described by the American Academy of Orthopaedic Surgery Patient Safety Committee. Our study of 300 cases revealed that only 20% of all cases and 7% of revision cases for infection had no modifiable risk factors. The most common risk factors were obesity (46%), anemia (29%), malnutrition (26%), and diabetes (20%). Cases with obesity or diabetes were associated with all histories of remote orthopedic infection, 89% of urinary tract infections, and 72% of anemia cases. The high prevalence of several modifiable risk factors demonstrates that there are multiple opportunities for perioperative optimization of such comorbidities.

Weight and body mass index change after total joint arthroplasty.

Obesity has become a leading public health issue in the United States. The goal of this study was to examine whether patients experience a significant change in body mass index (BMI) or weight after total joint arthroplasty. Previous studies have not corrected for the natural, annual positive BMI change in North Americans aged 29 to 73 years. Our study takes this natural weight gain into consideration in examination of total hip arthroplasty (THA) and total knee arthroplasty (TKA) populations. Our study population trended toward weight loss and BMI loss when weight was corrected for natural gain. Clinically significant weight loss, as determined by US Food and Drug Administration parameters, occurred in 19.9% of the study population when weight was corrected for natural gain. The TKA population exhibited a statistically significant (P<.05) weight loss and a clinically significant weight loss in 21.5% of the population. Patients with an initial BMI >30 exhibited a trend toward weight loss. This study was a level II retrospective study.

Estrogen coordinates translation and transcription, revealing a role for NRSF in human breast cancer cells.

Posttranscriptional regulation may enhance or inhibit estrogen transcriptional control to promote proliferation of breast cancer cells. To understand how transcriptome and translational responses coordinate to drive proliferation, we determined estrogen's global and specific effects on translation regulation by comparing the genome-wide profiles of total mRNA, polysome-associated mRNA, and monosome-associated mRNAs in MCF-7 cells after stimulation by 1 h of 10 nm 17beta-estradiol (E2). We observe three significant, novel findings. 1) E2 regulates several transcripts and pathways at the translation level. 2) We find that polysome analysis has higher sensitivity than total RNA in detecting E2-regulated transcripts as exemplified by observing stronger E2-induced enrichment of E2 expression signatures in polysomes more than in total RNA. This increased sensitivity allowed the identification of the repression of neural restrictive silencing factor targets in polysome-associated RNA but not total RNA. NRSF activity was required for E2 stimulation of the cell cycle. 3) We observe that the initial translation state is already high for E2 up-regulated transcripts before E2 treatment and vice versa for E2 down-regulated transcripts. This suggests that the translation state anticipates potential E2-induced transcriptome levels. Together, these data suggest that E2 stimulates breast cancer cells by regulating translation using multiple mechanisms. In sum, we show that polysome profiling of E2 regulation of breast cancer cells provides novel insights into hormone action and can identify novel factors critical for breast cancer cell growth.

How to treat the stiff total knee arthroplasty?: a systematic review.

BACKGROUND: Multiple modalities have been used to treat the stiff TKA, including manipulation under anesthesia (MUA), arthroscopy, and open arthrolysis. QUESTIONS/PURPOSES: We reviewed the literature to address three questions: (1) How many degrees of ROM will a stiff TKA gain after MUA, arthroscopy, and open arthrolysis? (2) Does the timing of each procedure influence this gain in ROM? (3) What is the number of clinically important complications for each procedure? METHODS: We performed a PubMed search of English language articles from 1966 to 2008 and identified 20 articles, mostly Level IV studies. RESULTS: For patients who have arthrofibrosis after TKA, the gains in ROM after MUA and arthroscopy (with or without MUA) are similar. Open arthrolysis seems to have inferior gains in ROM. MUA is more successful in increasing ROM when performed early but still may be effective when performed late. Arthroscopy combined with MUA still is useful 1 year after the index TKA. The numbers of clinically important complications after MUA and arthroscopy (with or without MUA) are similar. CONCLUSIONS: Stiffness after TKA is a common problem that can be improved with MUA and/or arthroscopic lysis of adhesions with few complications. The low quality of available literature makes it difficult to develop treatment protocols. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.