Technology Review: CT Scan-Guided, 3-Dimensional, Robotic-Arm Assisted Lower Extremity Arthroplasty.

Robotic-arm assisted lower extremity arthroplasty using computed tomography scan (CT)-based 3-dimensional (3D) modeling operative technologies has increasingly become mainstream over the past decade with over 550,000 procedures performed between first use in 2006 and November 2021. Studies have demonstrated multiple advantages with these technologies, such as decreased postoperative pain and subsequent decreased narcotic usage, decreased lengths of stay, less complications, reduced damage to soft tissues, decreased readmissions, as well as economic advantages in the form of meaningful cost savings for payors. The purpose of this report was to clearly and concisely summarize the good-to-high methodology peer-reviewed, published literature regarding CT scan-based, 3-dimensional robotically-assisted unicompartmental knee arthroplasty, total knee arthroplasty, and total hip arthroplasty stratified by: (1) prospective randomized studies; (2) database comparison studies; (3) national registry studies; (4) health utility studies; (5) comparison studies; and (6) basic science studies. A literature search was conducted and, after applying inclusion criteria, each study was graded based on the modified Coleman methodology score ("excellent" 85-100, "good" 70-84, "fair" 55-69, "poor" <54 points). A total of 63 of 63 good-to-excellent methodology score reports were positive for this technology, including 11 that demonstrated decreased pain and/or opioid use when compared to traditional arthroplasty techniques. The summary results of these high-quality, peer-reviewed published studies demonstrated multiple advantages of this CT scan-based robotic-arm assisted platform for lower extremity arthroplasty.

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.

Hip and Knee Arthroplasty Orthopedic Literature in Medical Journals-Is It Negatively Biased?

BACKGROUND: Healthcare policy is often determined by well-designed studies most often published in high-impact medical journals. However, concern about the presence of publication bias against lower-extremity arthroplasty-related studies has called into question some of the validity of certain reports. There are only a few studies investigating the presence of the bias in high-impact medical journals against lower-extremity arthroplasty intervention, particularly in the Journal of American Medical Association (JAMA), New England Journal of Medicine (NEJM), and the Lancet. Thus, the purpose of this study was to assess (1) the distribution of positive, neutral, and negative results; (2) the number of reports focused on lower-extremity arthroplasty complications among these 3 journals; and (3) difference in bias between 2 time periods (1975 to 1990 and 2000 to 2016). METHODS: A review of the literature from 3 major medical journals (NEJM, Lancet, and JAMA) was performed using PubMed electronic databases, which retrieved articles between January 1976 and December 2016. Studies were categorized as being positive, neutral, and negatively biased by 2 reviewers. Studies were categorized as reporting on lower-extremity arthroplasty-related complications if they were based on complications including deep vein thrombosis, infection, metal-related complication, fat embolism, readmission, or mortality. In addition, we have compared the journal bias between 2 different time points (1975 to 1990 and 2000 to 2016). Descriptive analyses were performed to assess frequencies. Chi-squared analysis was conducted for categorical variables, whereas a z-test was performed for dichotomous data. RESULTS: When assessing all 3 journals, there were 46 positive (30.3%), 46 negative (30.3%), and 60 neutral reports (39.5%). There was no statistically significant difference in classification proportions between the 3 groups (P = .905). There was a higher percentage of medical literature reporting on the complications of arthroplasty (55.9%); however, this was not statistically significant (z-score = 1.38; 95% confidence interval, 0.48-0.64; P = .17). There was no difference in overall journal reporting between 1975 to 1990 and 2000 to 2016 (P = .548). CONCLUSION: There was no evidence of publication bias of lower-extremity arthroplasty reports in the major medical journals (JAMA, NEJM, and Lancet). However, there were more published studies reporting on complications of lower-extremity arthroplasty. This may be due to systematic bias among journal editors in these journals, or due to low journal submission reporting noncomplications after arthroplasty intervention. We did not find the time period to be a factor in bias reporting of orthopedic literature in major medical journals. More work is needed to verify the results of this study.

Do Press Ganey Scores Correlate With Total Knee Arthroplasty-Specific Outcome Questionnaires in Postsurgical Patients?

BACKGROUND: The purpose of this study was to assess whether Center for Medicaid and Medicare services-implemented satisfaction (Press Ganey [PG]) survey results correlate with established total knee arthroplasty (TKA) assessment tools. METHODS: Data from 736 patients who underwent TKA and received a PG survey between November 2009 and January 2015 were analyzed. The PG survey overall hospital rating scores were correlated with standardized validated outcome assessment tools for TKA (Short form-12 and 36 Health Survey; Knee Society Score; Western Ontario and McMaster Universities Arthritis Index; University of California, Los Angeles; and visual analog scale) at a mean follow-up of 1154 days post-TKA. RESULTS: There was no correlation between PG survey overall hospital rating score and the above-mentioned outcome assessment tools. CONCLUSION: Our study shows that there is no statistically significant relationship between established arthroplasty assessment tools and the PG overall hospital rating. Therefore, PG surveys may not be an appropriate tool to determine reimbursement for orthopedists performing TKAs.

Does Length of Stay Influence How Patients Rate Their Hospitalization After Total Hip Arthroplasty?

BACKGROUND: The reimbursement for medical services by Medicare and Medicaid (CMS) has recently changed from fee-for-service to quality-based payments. This is being implemented through the use of patient administered surveys, most commonly Press Ganey. With a recent strive for fast-track total hip arthroplasty (THA), it is important to ascertain whether length-of-stay (LOS) in post-THA patients influences the Press Ganey scores and overall hospital ratings. Therefore, we looked at: 1) Which Press Ganey survey factors affect overall hospital rating in patients who have a short (=2) or longer (>2) length of stay; and 2) whether hospital satisfaction is different between patients who have varied lengths of stay. MATERIALS AND METHODS: A query of the Press Ganey database at our institution was performed between November 2009 and January 2015. We identified 692 patients who had a mean age of 62 years (range, 15 to 91 years). These patients were stratified into two cohorts based on LOS (=two days, n=403; >two days, n=289). Multiple regression analyses were performed using weighted means of each Press Ganey question category to identify their influence ( b) on hospital ratings. We assessed differences in demographics and survey responses between the two cohorts using x2 tests for categorical data and t-tests for continuous data. RESULTS: There was no statistically significant difference found between our two cohorts in hospital rating after adjusting for gender and ASA score. In patients who had short lengths-of-stay (LOS= two days), the overall hospital rating was most influenced by communication with nurses ( b=0.335, p= 0.004), followed by responsiveness of hospital staff ( b=0.313, p=0.006), and communication with doctors ( b=0.208, p=0.049) after adjusting for gender and ASA score. For patients who stayed longer (LOS>two days), the most important factor in hospital ratings was communication with nurses ( b=0.332, p= 0.007), followed by hospital environment ( b=0.312, p=0.002), communication with doctors ( b=0.233, p=0.013), and staff responsiveness (b=0.223 p=0.042). CONCLUSION: Short (LOS=2) and long (>two days) lengths of stay did not affect overall hospital rating. However, amongst both cohorts, communication with nurses, staff responsiveness, and communication with doctors were positively correlated with hospital ratings. Hospital environment also played a significant role in overall hospital ratings for patients who had an LOS >two days. More studies should be conducted to assess if the use of minimally invasive THA affects overall hospital ratings.

Quadriceps and Hamstring Muscle Strength Improves After Unicompartmental Knee Arthroplasty.

INTRODUCTION: The ability to reach functional capacity following knee arthroplasty depends on the strength of the quadriceps and hamstring muscles. Following total knee arthroplasty, weakness of these muscles can persist for up to one year postoperatively; however, this phenomenon is not well-studied in unicompartmental knee arthroplasty (UKA) patients. Therefore, we assessed: 1) quadriceps muscle strength; 2) hamstring muscle strength; and 3) correlation to functional outcomes. MATERIALS AND METHODS: A review of all patients with medial compartment osteoarthritis treated with UKA at a minimum of one-year follow-up was performed. This yielded 26 patients (32 knees), comprising of eight females and 18 males who had a mean age of 67 years (range, 47 to 83 years). Muscle strength was assessed pre-and postoperatively via dynamometer. Functional outcomes were assessed using Knee Society Scores (KSS). Comparisons of groups were performed by paired t-tests. RESULTS: At a minimum one-year postoperatively, quadriceps muscle strength was 27 Nm (range, 13 to 71Nm) and hamstring muscle strength was 19.5Nm (range, 7 to 81Nm). Quadriceps muscle strength increased by 40% (p=0.002) and hamstring muscle strength by 26% (p=0.057). The mean KSS pain was 97 points (range, 85 to 100 points) and mean KSS function was 90 points (range, 45 to 100 points) at the final follow-up. Range of motion was 125° (range, 110° to 135° ) at the final follow-up. The Pearson Correlation Coefficient for postoperative extension strength and postoperative flexion strength to postoperative KSS functional scores were 0.268 and 0.220 respectively. CONCLUSION: Within one-year following UKA, patients can expect restoration of quadriceps and hamstring muscle strength with a corresponding functional improvement. Although long-term follow-up is warranted to determine sustainability, the short-term results demonstrate excellent restoration of function.

Dual Mobility Acetabular Cups in Primary Total Hip Arthroplasty in Patients at High Risk for Dislocation.

INTRODUCTION: Postoperative dislocation occurs in approximately 2% of primary total hip arthroplasties (THAs). Risk factors associated with dislocation include: age of 70 years or older, body mass index (BMI) of 30 kg/m2 or greater, alcohol abuse, and neuro-degenerative diseases such as multiple sclerosis or Parkinson's disease. As a result, dual-mobility articulations, which have been typically used for revision procedures, have become an increasingly popular option for these "at risk" primary THAs. Few studies have assessed their use in this complex patient population. Therefore, the purpose of this study was to assess: 1) survivorship; 2) radiographic outcomes (cup migration, progressive radiolucencies, and changes in component position); 3) Harris Hip Scores; and 4) complications of the dual-mobility articulation in the setting of primary THA for patients at high risk for dislocation. MATERIALS AND METHODS: Five participating surgeons performed 495 primary cementless THAs between January 2011 and December 2013. During this time, four of the five surgeons used dual-mobility articulations whenever the acetabular cup size was 52 mm or greater to allow for a 28 mm head, while one surgeon used it when the cup size was less than 52 mm to allow for an effective head size of 38 mm. The remaining surgeon used it for all THAs. Of the 495 patients, 453 (92%) received dual-mobility articulations, of which, 43 patients (10%) were lost to follow-up before the two year minimum. The remaining 410 patients were further assessed to determine those who were considered high risk for dislocation (age = 70 years, BMI =30 kg/m2, had a diagnosis of alcohol abuse, or had a neuro-degenerative disorder). Two hundred forty-nine patients were included in the analysis (103 men, 146 women) who had a mean age of 66 years (range, 24 to 90 years). The mean follow-up was 3.3 years (range, 2 to 5 years). Kaplan-Meier analysis was performed to assess aseptic and all-cause acetabular cup survivorship. Radiographs were evaluated for cup migration, progressive radiolucencies, and any changes in component position. Clinical outcomes were assessed using the Harris Hip Score (HHS), and any surgery-related complications were recorded. RESULTS: The survivorship to aseptic failure (n= 1) and all-cause (aseptic, n= 1; septic, n= 1) Kaplan-Meier acetabular component survivorships were 99.6% (95% confidence interval [CI], 99.1% to 99.9%) and 99.2% (95% CI, 98.5% to 99.9%), respectively. One hip had impingement of an anteverted cup, resulting in trunnion notching, and required revision of the cup and stem. Another hip had a deep infection, which was treated with a two-stage revision procedure. There were no dislocations in this cohort. No progressive radiolucencies or component positional changes were seen on radiographic assessment. Patients reported a mean HHS of 92.5 (range, 47 to 100 points) at final follow-up. Surgical complications included one polyethylene liner that was incompletely seated, and one loose femoral stem, which required revision of only the femoral component. CONCLUSIONS: At short-term follow-up, dual-mobility articulations in primary THA offer survivorship, outcomes, and complications comparable to conventional THA designs in patients who are at increased risk for postoperative dislocation. Serious complications, such as polyethylene wear and intraprosthetic dislocations, have occasionally been reported with the use of these components. Therefore, future studies should be prospective, multi-center, and have longer-term follow-up to determine the true benefit of modular dual-mobility articulations in patients who are at high risk for dislocation.

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.

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

BACKGROUND: Centers for Medicare and Medicaid Services are now using results from patient satisfaction surveys, such as Press Ganey, for reimbursement. It is unknown what factors influence scores on satisfaction surveys in post-total hip arthroplasty (THA) patients. The purpose of this study was to evaluate what influences these scores in THA patients. Specifically, we aimed to evaluate: (1) how pain control affects the patients' perception of their orthopedist, nursing staff, and overall hospital satisfaction; (2) the individual impact of these factors on overall hospital satisfaction after THA; and (3) the impact of lengths of stay, age, body mass index (BMI), and American Society of Anesthesiology (ASA) scores on overall satisfaction. METHODS: To assess whether pain management influences patients' perception of the orthopedist, a correlation analysis was performed between pain control and perception of their doctor. Similar analyses were performed to determine the relationship between pain management and patients' perception of their treating nurse, as well as overall satisfaction. A multiple regression analysis was performed to determine which of the aforementioned factors have the greatest impact on overall satisfaction. To determine the impact of length of stay on overall hospital satisfaction, a correlation analysis was performed between these 2 variables. Similar analyses were performed for age, BMI, and ASA scores. RESULTS: Patients' perception of pain control was significantly positively correlated with the perception of their orthopedist, nurse, and overall hospital satisfaction. Multiple regression analysis demonstrated that patients' perception of nurses and orthopedists yielded a significantly positive influence on overall hospital satisfaction. A significant negative correlation existed between lengths of stay and hospital satisfaction. There were no significant correlations between age, BMI, and ASA scores and overall hospital rating. CONCLUSION: Post-THA patients associate pain management with hospital satisfaction, as well as their perception of their treating nurses and orthopedists. Overall satisfaction was most impacted by patients' perception of their nurse, followed by their orthopedist. In addition, there was an association between shorter length of stay and higher overall satisfaction. These results are of paramount importance because by recognizing factors that affect scores on satisfaction surveys, orthopedic surgeons can direct efforts to improve post-THA satisfaction and optimize reimbursements.

What Influences How Patients Rate Their Hospital After Total Knee Arthroplasty?

INTRODUCTION: There is increasing pressure from Centers for Medicare and Medicaid Services (CMS) to report quality measures for all hospitalizations. These quality measures are determined based on results from satisfaction surveys, such as Press Ganey® (PG) (Press Ganey® Performance Solutions, Wakefield, Massachusetts). Included in this particular survey element are questions regarding staff, including nurses and doctors, as well as items such as pain control. The results of these surveys will dictate the amount doctors are compensated for their services. Therefore, this study was undertaken to evaluate the effect of treating orthopaedists and nurses, as well as pain control, on PG surveys in patients who underwent total knee arthroplasty (TKA). Specifically, we aimed to ascertain the effect of these factors on how post-TKA patients perceive: 1) their orthopaedist, and 2) their overall surgical experience. MATERIALS AND METHODS: We queried the Press Ganey® Database for all patients who underwent a TKA at our institution between November 2009 and January 2015. A weighted mean of question domains was utilized since each had multiple questions. In order to assess if pain management influences orthopaedist perception, a correlation analysis was performed between pain control and perception. In order to assess the influence of pain management on surgical experience, we performed a correlation analysis between pain control and overall hospital rating. A multiple regression analysis was performed using the hospital rating as the dependent variable to determine the most influential factors on surgical experience. RESULTS: Our analysis demonstrated a significantly positive correlation between patient perception of their pain control and their orthopaedist. There was a significant positive correlation between patient's perception of their pain control and their overall surgical experience. Multiple regression analysis using overall surgical experience as the dependent variable demonstrated a significant positive influence of perception of nurses and orthopaedists. Pain management positively influenced surgical experience; however, this was not significant. CONCLUSIONS: We found that perception of pain control in post-TKA patients affects perception of the treating orthopaedists, as well as their overall surgical experience. In addition, perception of orthopaedists and nurses both outweigh perception of pain control on overall surgical experience, with nurses being the most important. Orthopaedists should focus on staff education-particularly nurses-and educate them in order to optimize results on PG surveys and, ultimately, improve patient satisfaction. Further studies should correlate current standardized scoring systems and questionnaires for TKA with PG surveys in order to recognize gaps that need to be bridged to improve post-TKA patient satisfaction.

Tobacco use may be associated with increased revision and complication rates following total hip arthroplasty.

The purpose of this study was to compare the clinical outcomes of total hip arthroplasty in patients who were smokers to patients who were non-smokers. All total hip arthroplasties performed between 2007 and 2009 were reviewed to identify patients who indicated tobacco use. There were 110 smokers who were matched in a 1:2 ratio to 220 non-smoking patients. At a mean follow-up of 51 months (range, 24 to 72 months), smokers had an overall significantly lower survivorship of 92% (n = 9 revisions), compared to 99% (n = 2 revisions) in non-smokers. In addition, there were five complications in smokers (one pneumonia, three superficial infections, and one deep peroneal nerve palsy) compared to none in non-smokers. These results indicate that patients who smoke had higher overall revisions and postoperative complications.

Opioid use prior to total hip arthroplasty leads to worse clinical outcomes.

PURPOSE: The purpose of this study was to compare the clinical outcomes of patients undergoing total hip arthroplasty (THA) who had been using narcotic medications prior to surgery to those who had not used them. METHODS: Fifty-four patients (62 hips) who had required opioid analgesia for hip pain in the three months prior to THA were compared to a matched group of opioid-naïve patients. Narcotic consumption was converted to a standardized morphine equivalent dose and compared between both groups of patients during their hospital stay, after six weeks, and at final follow-up. Other outcome measures included clinical outcome scores and the proportion of patients remaining on narcotic pain medication at final follow-up. RESULTS: The narcotic group required significantly higher total daily opioid doses as inpatients had a longer hospital stay and a higher proportion of patients who remained on opioids at six weeks and at final follow-up. Of the patients who were taking opioids pre-operatively, 81 % were able to wean off opioids at final follow-up. At a mean post-operative follow-up of 58 months (range, 24-258 months), Harris hip scores were lower in the narcotic group, with a mean of 84 compared to 91 points in the matching group. However, in both cohorts, there were significant improvements in Harris hip scores compared to pre-operative outcomes. CONCLUSIONS: Patients who use narcotics prior to total hip arthroplasty may be more likely to suffer from opioid-induced hyperalgesia after surgery and have worse clinical outcomes. When possible, efforts should be made to use other modes of analgesia or wean patients from their use prior to total hip arthroplasty.

Bariatric orthopaedics: total knee arthroplasty in super-obese patients (BMI > 50 kg/m2). Survivorship and complications.

BACKGROUND: Some studies have suggested that patients who are super obese (BMI > 50 kg/m(2)) may have poorer outcomes and more frequent complications when undergoing TKA compared with those who have lower BMI, however, the literature on this is scant. QUESTIONS/PURPOSES: The purpose of this study was to compare a group of super-obese patients undergoing TKA with a matched group of patients with BMI less than 30 kg/m(2) in terms of (1) implant survivorship, (2) complications, (3) functional parameters, and (4) intraoperative variables (including operative time and estimated blood loss). METHODS: One-hundred one knees in 95 patients (21 men, 74 women) who had a minimum BMI of 50 kg/m(2) and who had undergone a primary TKA at one of the four high-volume institutions were compared with a group of patients who had a BMI less than 30 kg/m(2) who were matched by age, gender, preoperative clinical scores, and mean followup. End points evaluated by chart review included implant survivorship, medical and surgical complications, functional parameters (The Knee Society outcome scores and ROM), and intraoperative variables at a mean followup of 62 months (range, 36-85 months). RESULTS: With the numbers available, there were no differences in aseptic implant survivorship (94% versus 98%, p = 0.28), however, medical and surgical complication rates (14% versus 5%, OR: 3.1, 95% CI=1.07-8.9; p = 0.037) were significantly higher in the super-obese patients compared with the nonobese matching group, respectively. Super-obese patients also achieved lower mean Knee Society functional scores (82 versus 90 points, p = 0.004) and smaller gains in flexion arc ROM (14° versus 21°, p = 0.009); they also lost more blood during surgery and experienced longer surgical anesthesia times compared with the matched group, respectively. CONCLUSIONS: With the numbers available, we could not identify what might have been modest differences in implant survivorship, however, complications were more frequent and functional outcomes were significantly lower in super-obese patients. Other studies similarly have found inferior outcomes in this challenging group of patients. Our data may be considered pilot data for future prospective studies with longer followup.

Critical review of minimally invasive approaches in knee arthroplasty.

Despite high survivorship for total knee arthroplasty, many reports have described low patient-satisfaction rates. Standard parapatellar approaches have been linked with decreased quadriceps muscle strength, which may in turn lead to prolonged rehabilitation and altered kinematics. Although technically demanding, minimally invasive techniques offer the potential for shorter recovery times and improved strength. Our purpose was to compare perioperative factors, the clinical and radiographic outcomes, complications, and survivorship of several minimally invasive approaches to each other and to the conventional medial parapatellar approach. A total of 23 level I or II studies were reviewed. There were no statistically significant differences in perioperative factors, clinical or radiographic outcomes, survivorship, or complication rates between patients the various minimally invasive approaches to a standard approach. The only significant difference observed was in recovery of quadriceps muscle function (shorter in patients who had a minimally invasive approach). The minimally invasive lateral approach had more complications than the other minimally invasive approaches. The mini-midvastus approach had the best clinical outcomes at 1 and 3 months when compared with other minimally invasive approaches and standard approaches. The mini-subvastus approach had the lowest rate of complications, overall. Further multicenter randomized trials are needed to determine the minimally invasive approach that best improves outcomes while minimizing complications.

Lumbar spinal stenosis impairs function following total knee arthroplasty.

Lumbar spinal stenosis is a common cause of lower back and leg pain in older adults. Stenosis is not considered a contraindication for total knee arthroplasty (TKA); however, it is unclear whether it is associated with less than optimal postoperative outcomes. In a multicenter review of TKAs, 115 patients with lumbar disease were matched by age, gender, body mass index, type of procedure, and length of follow-up to patients who did not have stenosis. Spinal stenosis was found to be associated with significantly lower Knee Society objective and function scores compared with patients without stenosis. There was no observed difference in the revision rates (1%) or radiographic outcomes. Surgeons should consider cautioning patients that they can expect relief of arthritic symptoms following TKA, but they may continue to experience limitations in postoperative function relative to their expectations.

Effectiveness of various hospital-based solutions against community- acquired methicillin-resistant Staphylococcus aureus.

Periprosthetic infections with methicillin-resistant Staphylococcus aureus (MRSA) can be particularly burdensome and difficult to eradicate. One of the measures that infection control officers have emphasized in our hospitals has been the use of various hand sanitizers throughout the hospital. Our objective was to determine the level of growth inhibition of common hand sanitizers and surgical scrub solutions that are used to prevent the spread of community-acquired strains of MRSA. Various hospital and surgical agents (n = 13) were applied to community-acquired MRSA bacteria that had been cultured on agar plates. These different commercially available solutions were incubated for 48 h, and the plates were assessed to determine the level of growth inhibition (0, 25, 75, or 100%). The negative control was a test in which no agent was added to the MRSA culture, while a positive control tested 100% alcohol. Eight of the solutions tested had 100% growth inhibition, four solutions had partial growth inhibition effects, and one solution did not inhibit MRSA. Of the solutions with alcohol, the 62% solution did not kill MRSA, while the 80% solution only inhibited MRSA. Both the 95 and 100% alcohol solutions had 100% growth inhibition. Of the two surgical scrub solutions, only the one with iodine had 100% growth inhibition, whereas the solution with chloroxylenol (PCMX 3%) had only partial growth inhibition. This study suggests that the solutions with high levels of alcohol, chlorhexidine, or iodine appear to better kill MRSA and might best be used to prevent the spread of community-acquired MRSA in both the hospital and the surgical environment.

Increased revision rates after total knee arthroplasty in patients who smoke.

The purpose of this study was to compare the clinical outcomes of total knee arthroplasty in patients who reported a history of tobacco use with those who were nonsmokers. Between 2006 and 2009, there were 131 total knee arthroplasties performed in patients who were smokers and 490 in patients who did not smoke. At a mean follow-up of 47 months (range, 24-79 months), the patients who were smokers had a statistically decreased overall survivorship of 90% (13 revisions) compared with 99% (5 revisions) in the nonsmokers. Surgical complication rates were not significantly different between the 2 groups; however, there was a significant difference in medical complications. Total knee arthroplasty in smokers has a higher risk of negative clinical outcomes compared with nonsmokers.

TKA results are not compromised by previous arthroscopic procedures.

This study investigated whether two or more previous arthroscopic procedures had an effect on the outcomes of total knee arthroplasty (TKA). We compared 60 patients (62 knees) who had a mean age of 56 years, a mean follow-up of 39 months (range, 26 to 68 months), and a minimum of two arthroscopic procedures before their TKA with a group of patients (n = 438) who underwent TKAs without any previous knee surgery. Clinical outcome was evaluated using Knee Society objective and function scores. Implant survivorship, with revision for aseptic component failure as an end point, was 98% in both cohorts. In the postarthroscopic group, the mean Knee Society objective and function scores improved to a mean of 92 and 89 points, respectively. Radiographic analysis did not find any differences between the two groups. In conclusion, the authors did not find that earlier arthroscopic procedures negatively affected the outcome of TKA.

Total knee arthroplasty in patients 40 years and younger.

Total knee arthroplasty (TKA) is a procedure with excellent clinical results in older patients with a primary diagnosis of osteoarthritis. Many younger patients undergo unicompartmental or high tibial osteotomy rather than TKA, but are not always good candidates for these joint-preserving procedures. The purpose of this study was to review the outcomes of patients 40 years of age and under who underwent TKA. We identified 33 patients (38 knees) who were 40 years of age or less at the time of surgery. These patients had a mean age of 36 years (range, 23 to 40 years), and were followed for a mean of 49 months (range, 16 to 101 months). The survival rate in the study cohort was 97%. For the young patient who is not a candidate for other types of joint preserving procedures, in the senior authors' experience total knee arthroplasties have performed well.