Search

Skin closure for total knee arthroplasty (TKA) typically focuses on promoting optimal healing, while preventing wound complications and infection, allowing for functionality and immediate ambulation, and providing for excellent cosmesis. In this systematic review and meta-analysis of the literature, we will focus on closure of the skin. Specifically, we assessed: (1) wound complication risk of different techniques and (2) closing time of different sutures/techniques. There were 20 reports on infection risk and closing time. Meta-analyses focused on the qualifying studies for closing time and wound complication risk reports were also performed. These studies (378 patients) demonstrated overall lower wound complication risks with the use of barbed compared with traditional sutures (3% vs. 6%, p

Given the current healthcare economic environment, substantial efforts have been made to help streamline the in-hospital care for total knee arthroplasty (TKA) patients. While potential cost-reducing factors have been identified in the literature, analyses specifically considering post-anesthesia care unit (PACU) lengths of stay (LOS) are lacking. Therefore, the purpose of this study was to identify factors associated with (1) longer PACU LOS as well as (2) longer Hospital LOS. Prospectively collected TKA data from seven participating hospitals within a large health system were evaluated for patient demographics, body mass indices, Charlson Comorbidity Indices (CCI), surgeon volumes/training, admission types, anesthesia types, PACU LOS, and overall hospital LOS. Complete data was available for 1,690 patients (1,082 females, mean age: 67 years). Univariate and multivariate analytical models were constructed to identify which factors were predictive of longer PACU and overall hospital LOS. Same-day admissions, higher volume surgeons (≥ 100 cases per year), fellowship-trained arthroplasty surgeons, and longer operative times were associated with longer PACU LOS (p 0.05). These data identify associative factors for PACU LOS, as well as the influence of time spent in the PACU on overall hospital LOS. Interestingly, this analysis revealed that patients of arthroplasty fellowship-trained and higher-volume surgeons had longer PACU LOS; however, this could be explained by the observation that these particular surgeons tend to perform more complex deformity cases. Also of importance, increased PACU LOS, meaning the patient spent more time in a high-monitored setting immediately after surgery, did not necessarily confer a longer overall hospital LOS. Based on these data, it may be more beneficial to identify alternate sources than time spent in the operating room or PACU to potentially help reduce overall hospital LOS. Level of Evidence II, prospective cohort

Dressings for total knee arthroplasty (TKA) typically focus on promoting optimal healing, while preventing infection, allowing for functionality and immediate ambulation, while providing for excellent cosmesis. We have previously described four aspects of closure after TKA involving the: (1) deep fascial layer; (2) subdermal layer; (3) intradermal layer, including the subcuticular region; and (4) a specific aseptic dressing. In this meta-analysis and systematic review of the literature, we will focus on the dressing. Specifically, we assessed: (1) infection risk of different techniques; (2) re-operation or readmission risk; and (3) length of time until dressing change needed. There were 16 reports on infection risk, re-operation risk, and length of time until change needed. A meta-analysis focused on the qualifying wound complication risk reports was also performed. The meta-analysis including four studies (732 patients) demonstrated overall lower wound complication risk with the use of adhesives and mesh dressings (odds ratio 0.67) versus traditional closures. Additionally, studies demonstrated fewer re-operations and readmissions with the use of adhesives and mesh dressings. Furthermore, one report demonstrated mesh dressings persist longer than silver dressings. Therefore, multiple recent reports suggest superior outcomes when using adhesive and mesh dressings for TKAs.

The aim of this study was to track the annual rates and trends of overall, deep, and superficial surgical site infections (SSIs) following total knee arthroplasty using the most recent results from a large and nationwide database. A total of 197,192 cases were performed between 2012 and 2016 from a nationwide database stratified into years and based on superficial and/or deep SSIs. Cohorts were analyzed individually and then combined to evaluate overall SSI rates. The infection incidence for each year was calculated. After a 6-year correlation and trends analysis, univariate analyses were performed to compare the most recent year, 2016, with each of the preceding 4 years. Overall, there was a downward trend in overall SSI rates over the study period (2012–2016, with the lowest rate occurring in the most recent year, 2016 [0.11%]). Additionally, there was a decreasing trend for superficial SSI, with the lowest superficial SSI incidence occurring in 2016 (0.47%) and the greatest incidence occurring in 2012 (0.53%). An overall trend of decreasing SSI rates was observed nationwide over the 5-year period evaluated. A similar decreasing trend was also noted specifically for deep SSI rates, which can be potentially more complicated to manage, and result in decreased implant survivorship. The down trending SSI rates observed give potential credence to the value for newer and developing SSI preventative therapies as well as improved medical and surgical patient management. Nevertheless, there is still room for improvement, and continued efforts are needed to further lower SSIs after total knee arthroplasty.

This study compared surgeon cervical (C) spine postures and repetitive motions when performing traditional manual total knee arthroplasty (MTKA) versus robotic-assisted TKA (RATKA). Surgeons wore motion trackers on T3 vertebra and the occiput anatomical landmarks to obtain postural and repetitive motion data during MTKA and RATKA performed on cadavers. We assessed (1) flexion–extension at T3 and the occiput anatomical landmarks, (2) range of motion (ROM) as the percentage of time in the flexion–extension angle, (3) repetition rate, defined as the number of the times T3 and the occiput flexion-extension angle exceeded ±10°; and (4) static posture, where T3 or occiput postures exceed 10° for more than 30 seconds. The average T3 flexion–extension angle for MTKA cases was 5-degree larger than for RATKA cases (19 ± 8 vs. 14 ± 8 degrees). The surgeons who performed MTKA cases spent 15% more time in nonneutral C-spine ROM than those who performed RATKA cases (78 ± 25 vs. 63 ± 36%, p

Implant malalignment during total knee arthroplasty (TKA) may lead to suboptimal postoperative outcomes. Accuracy studies are typically performed with experienced surgeons; however, it is important to study less experienced surgeons when considering teaching hospitals where younger surgeons operate. Therefore, this study assessed whether robotic-arm assisted TKA (RATKA) allowed for more accurate and precise implant position to plan when compared with manual techniques when the surgery is performed by in-training orthopaedic surgical fellows. Two surgeons, currently in their fellowship training and having minimal RATKA experience, performed a total of six manual TKA (MTKA) and six RATKAs on paired cadaver knees. Computed tomography scans were obtained for each knee pre- and postoperatively. These scans were analyzed using a custom autosegmentation and autoregistration process to compare postoperative implant position with the preoperative planned position. Mean system errors and standard deviations were compared between RATKA and MTKA for the femoral component for sagittal, coronal, and axial planes and for the tibial component in the sagittal and coronal planes. A 2-Variance testing was performed using an α = 0.05. Although not statistically significant, RATKA was found to have greater accuracy and precision to plan than MTKA for: femoral axial plane (1.1° ± 1.1° vs. 1.6° ± 1.3°), coronal plane (0.9° ± 0.7° vs. 2.2° ± 1.0°), femoral sagittal plane (1.5° ± 1.3° vs. 3.1° ± 2.1°), tibial coronal plane (0.9° ± 0.5° vs. 1.9° ± 1.3°), and tibial sagittal plane (1.7° ± 2.6° vs. 4.7° ± 4.1°). There were no statistical differences between surgical groups or between the two surgeons performing the cases. With limited RATKA experience, fellows showed increased accuracy and precision to plan for femoral and tibial implant positions. Furthermore, these results were comparable to what has been reported for an experienced surgeon performing RATKA.

Background Newer generation cementless total knee arthroplasty (TKA) designs have provided stronger osteointegration between the implant and bone. Despite excellent survivorship and outcomes with cemented TKAs, areas of concern within the bone–cement interface remain a concern and necessitate studies on alternative constructs. This study assesses: (1) implant survivorship; (2) clinical outcomes; and (3) complications with radiographic outcomes at a 5-year minimum follow-up of cementless highly porous titanium-coated baseplates in TKAs. Methods Part of this study has been reported. We retrospectively reviewed a prospectively collected database at a single high-volume institution between July 1, 2013 and June 30, 2014 for patients who underwent a primary TKA using cementless highly porous titanium-coated baseplate implants. Patients were evaluated clinically at postoperative follow-up visits at a minimum of 5 years. To calculate the survivorship, Kaplan–Meier analysis was performed to determine all-cause, aseptic, and septic implant survivorship at each final follow-up for all patients. Results A total of 228 TKAs were performed and followed for a minimum of 5 years (range, 5–6 years). As of the latest follow-up, one case of septic loosening of the patellar button and one case of patellar dislodgment secondary to physical manipulation were recorded and revised. Overall, the cohort displayed implant survivorship of 99.5% at 5-year minimum follow-up. Improvements were seen in both Knee Society pain and function scores and were 37 points (range, 17–60 points) and 28 points (range, 15–47 points), respectively. The mean improvement in flexion was 17.8 (range, –20 to 40 degrees) and mean improvement in extension was –5.5 (range, –30 to 5 degrees). Discussion Cementless TKAs serve as strong alternative choice to cemented TKAs. Although cemented fixation is commonly known as the gold standard, results of this study confirm the findings of previous investigations on the survivorship of cementless TKA implants. Therefore, patients who undergo primary TKA with a cementless tritanium baseplate can expect excellent clinical outcomes at a 5-year minimum follow-up.

Large-scale studies evaluating the effects of Parkinson's disease (PD) on primary total knee arthroplasty (TKA) are limited. The purpose of this study was to determine if PD patients undergoing primary TKA have increased: (1) medical complications; (2) implant-related complications; (3) readmission rates; and (4) costs. A query was performed using an administrative claims database. The study group consisted of all patients undergoing primary TKA who had a history of PD. Matched non-PD patients undergoing primary TKA served as a control group. The query yielded 72,326 patients (PD = 18,082; matching cohort = 54,244). Pearson's chi-square tests, logistic regression analyses, and Welch's t-tests were used to test for significance between the cohorts. Primary TKA patients who had PD were found to have greater incidences and odds of medical complications (4.21 vs. 1.24%; odds ratio [OR]: 3.50, 95% confidence interval [CI]: 3.15–3.89, p

A greater number of medically complex patients with multiple comorbidities are now more readily considered for total knee arthroplasty (TKA). Therefore, the purpose of this study was to determine whether comorbidity burden, measured with the Elixhauser Comorbidity Index (ECI), correlated with 90-day medical complications and longer in-hospital lengths-of-stay (LOS) in TKA patients. The PearlDiver supercomputer was queried for all primary TKA patients in the Medicare Standard Analytic Files from 2005 to 2014 using International Classification of Disease, 9th edition codes. Patients were included based on ECI scores, ranging from 1 to 5. ECI 1 patients served as the control cohort, while ECI 2, 3, 4, and 5 patients were considered study cohorts. Each study cohort was matched based on age and gender to the control cohort, resulting in a total of 715,398 patients included for analysis (ECI 1, n = 144,072; ECI 2, n = 144,072; ECI 3, n = 144,072; ECI 4, n = 144,072; ECI 5, n = 139,110). Logistic regression analyses were performed to compare 90-day medical complications and Welch's t-tests were performed to compare LOS between the cohorts. Patients with higher ECI scores were more likely to develop medical complications and have longer LOS compared with matched patients in the control cohort. Compared with matched ECI 1 patients, patients with ECI scores of 2 (odds ratio [OR]: 1.19, 95% confidence interval [CI]: 1.14–1.24), 3 (OR: 1.27, 95% CI: 1.21–1.32), 4 (OR: 1.32, 95% CI: 1.27–1.38), and 5 (OR: 1.33, 95% CI: 1.27–1.39) were significantly more likely to develop 90-day medical complications. Additionally, the mean LOS of patients in the ECI 2 (2.59 ± 1.49 vs. 2.73 ± 1.52 days), ECI 3 (2.59 ± 1.49 vs. 2.88 ± 1.51 days; p

The number of total knee arthroplasties (TKAs) performed in the United States has increased considerably in recent years, with a major contribution from younger patients. Maximizing survivorship of these implants has always been a point of emphasis. Early TKA designs with cementless fixation were associated with high rates of complications and implant failures. However, recent advances in cementless designs have shown excellent results. The decision to use cemented or cementless fixation for patients undergoing TKA is typically based on the surgeon's experience and preference. However, several patient characteristics must also be taken into account. The purpose of this review was to describe the clinical outcomes of studies in which a cementless TKA system was utilized for patients who (1) were less than 60 years of age, (2) were greater than 75 years of age, (3) were obese, (4) had rheumatoid arthritis, and (5) had osteonecrosis of the knee. Based on the studies included in this review, it appears that cementless fixation is a viable option for patients who have all of the above demographics.

Robotic-assisted unicompartmental knee arthroplasty (RAUKA) is an emerging area of interest. The purpose of this study was to compare (1) different patient demographic profiles; (2) annual primary and revision utilization rates; (3) risk factors for revision procedures; and (4) survivorship between RAUKA and manual UKA (MUKA). Using the PearlDiver database, patients who underwent RAUKA or MUKA between 2005 and 2014 within the Medicare database were identified, yielding a total of 35,061 patients (RAUKA = 13,617; manual = 21,444). Patient demographics (age, gender, comorbidities, Charlson-Comorbidity Index, and geographic region) were compared between cohorts. Annual primary and revision utilization rates as well as risk factors for revision procedures were also compared. Kaplan–Meier survivorship was also calculated. The Pearson χ2 test was used to test for significance in patient demographics, whereas the Welch t-test was used to compare the incidence of revisions as well as the revision burden (proportion of revisions to total sum of primary and revision procedures). Multivariate binomial logistic regression analysis was performed to compare risk factors for revision procedures. There were statistically significant differences in RAUKA versus MUKA patients with respect to age (p

This study performed a health care utilization analysis between robotic arm assisted total knee arthroplasty (rTKA) and manual total knee arthroplasty (mTKA) techniques. Specifically, we compared (1) index costs and (2) discharge dispositions, as well as (3) 30-day (4) 60-day, and (5) 90-day (a) episode-of-care costs, (b) postoperative health care utilization, and (c) readmissions. The 100% Medicare Standard Analytical Files were used for rTKAs and mTKAs performed between January 1, 2016, and March 31, 2017. Based on strict inclusion–exclusion criteria and 1:5 propensity score matching, 519 rTKA and 2,595 mTKA patients were analyzed. Total episode payments, health care utilization, and readmissions, at 30-, 60-, and 90-day time points were compared using generalized linear model, binomial regression, log link, Mann–Whitney, and Pearson's chi-square tests. The rTKA versus mTKA cohort average total episode payment was US$17,768 versus US$19,899 (p

The potential added costs of managing fibromyalgia patients after total knee arthroplasty (TKA) have not been assessed. Therefore, the purpose of this study was to perform a cost analysis of fibromyalgia versus nonfibromyalgia patients who underwent TKA. Specifically, we evaluated the following episodes of care: (1) readmission rates, (2) total costs, (3) total reimbursements, and (4) net losses for surgical and medical complications. Patients who underwent TKAs between 2005 and 2014 from the Medicare Standard Analytical Files of the PearlDiver supercomputer were propensity score matched by patients with and without fibromyalgia in a 1:1 ratio based on age, sex, and the Charlson Comorbidity Index, yielding a total of 305,510 patients distributed equally between the cohorts for analysis. Odds ratios (ORs), 95% confidence intervals (CIs), and p-values were calculated. Mean costs, total costs, and total reimbursements were assessed as along with total net losses, which were defined as total costs minus total reimbursements. Fibromyalgia patients had similar 90-day readmission rates compared with nonfibromyalgia patients (OR: 1.03; 95% CI: 1.00–1.06; p = 0.06) but incurred lower readmission costs (US$2,318,384,295 vs. US$2,534,482,404; p

The purpose of this meta-analysis was to assess the evidence supporting the use of cementless versus cemented total knee arthroplasties (TKAs). Specifically, we evaluated (1) all-cause survivorship, (2) aseptic survivorship, and (3) functional outcomes (Knee Society Scores [KSS], Oxford Knee Scores, Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] scores, and ranges of motion [ROMs]). A literature search was performed for studies that evaluated cementless versus cemented TKAs published between 2000 and 2017. Selected studies included three randomized controlled trials, three retrospective observational studies, and one prospective observational study that met the following criteria: (1) primary TKAs, (2) compared cementless and cemented TKAs, (3) implant survivorship that described the causes of failure, and (4) at least one functional outcome. To compare the two cohorts, pooled odds ratios (OR) and 95% confidence intervals (95% CI) were used to calculate tibial and femoral implant survivorship, and pooled mean differences (MD) and 95% CI calculated the functional scores and ROMs. Based on pooled data from the few number of studies, cementless TKAs had a better all-cause survivorship (OR = 0.37; 95% CI, 0.15–0.92) and tended to have a better aseptic survivorship (OR = 0.44; 95% CI, 0.17–1.14). However, this is likely due to the 83.3% weight of the single cementless study potentially influencing the analysis. There were no differences in terms of KSS knee (MD = 1.03; 95% CI, −1.13–3.20) or function scores (MD = 5.36; 95% CI, –3.75–14.51), Oxford knee scores (MD = 0.36; 95% CI, –3.84–4.56), or WOMAC scores (MD = 0.62; 95% CI, –0.87–2.11). Moreover, there was no difference in ROMs (MD = 1.47; 95% CI, –0.11–3.05). Cementless TKA had a better all-cause survivorship when compared with cemented fixation, and similar functional outcomes were demonstrated. However, these findings are based on only a few number of studies (n = 7). Therefore, additional prospective, randomized control trials need to be performed to best compare cementless versus cemented outcomes.

This study evaluated whether the preoperative use and timing of the use of hyaluronic acid (HA) and/or corticosteroid (CS) injections were associated with an increased risk of periprosthetic joint infections (PJIs) following primary total knee arthroplasty (TKA). We tested the hypothesis that preoperative injection of HA or CS within 3 months prior to primary TKA was associated with an increased risk of PJI by specifically evaluating the association between PJI risk and (1) injection type; (2) timing; (3) patient demographic factors; and (4) surgery-related factors, such as surgeon injection volume, knee arthroscopy (pre- and postoperative), and hospital length of stay. The 5% Medicare part B claims database was queried for patients who received CS and/or HA injections. Cox proportional hazards regressions evaluated the risk of PJIs after TKA, adjusting for patient and clinical factors, as well as propensity scores. The unadjusted incidence of PJI at 2-year post-TKA was 0.75% for the CS group, 0.89% for the HA group, 0.96% for both CS and HA group, and 0.75% for those who did not use HA or CS in the 12 months before TKA. For patients who used HA and/or CS within 3 months prior to TKA, the unadjusted incidence of PJI at 2-year post-TKA was 0.75% for the CS group, 1.07% for the HA group, and 1.00% for both CS and HA group, compared with 0.77% for those who did not use HA or CS. The number of injections performed per year was inconsistently associated with PJI risk. Overall, we found that intra-articular injections given within the 4-month period prior to TKA were not associated with elevated PJI risk (evaluated at 1, 3, 12, and 24 months after the index TKA) within the elderly Medicare patient population.

Component position of total knee arthroplasty (TKA) has been shown to influence prosthetic survivorships and clinical outcomes. Our objective was to compare the three-dimensional accuracy to plan of robotic-arm assisted TKA (RATKA) with conventional TKA for component position. We conducted a nonrandomized, prospective study comparing 143 RATKA with 86 conventional TKA operated at four U.S. centers between July 2016 and October 2018. Computed tomography (CT) scans obtained approximately 6 weeks postoperatively were analyzed using anatomical landmarks. Absolute deviation from surgical plans were defined as the absolute value of the difference between the CT measurements and surgeons' femoral and tibial component mechanical varus/valgus alignment, tibial component posterior slope, and femoral component internal/external rotation. Differences of absolute deviations were tested using stratified Wilcoxon's tests that controlled for study center. Patient-reported outcome measures collected through 1 postoperative year were modeled using multiple regression controlling for age, sex, body mass index, study center, and the preoperative score. RATKA demonstrated greater accuracy for tibial component alignment (median [25th, 75th percentiles] absolute deviation from plan of all centers combined for conventional vs. RA, 1.7 [0.9, 2.9] vs. 0.9 [0.4, 1.9] degrees, p

Because of the early follow-up positive outcomes with cementless fixation, continued evaluations need to be performed to ensure longer-term efficacy. Additionally, although many studies report on the results of femoral and tibial component fixation, few studies report specifically on patellar outcomes. Therefore, the purpose of this study was to report on the: (1) implant survivorship; (2) complications; and (3) radiographic outcomes in a large cohort of patients who received cementless total knee arthroplasties (TKAs), with particular attention to the patellar component. A total of 261 patients who underwent cementless TKA by a single, high-volume academic surgeon were studied. Patients had a mean age of 66 years and were distributed between 192 women (74%) and 69 men. All patients received the same cementless tibial, femoral, and patellar components. Mean follow-up period was 4.5 years (range, 4–5 years). Primary outcomes evaluated included all postoperative complications, with particular emphasis on the patellar component. Only one patellar loosened leading to a patellar aseptic loosening rate of 0.3% (1 of 261). The one patellar loosening was the component being dislodged after a manipulation under anesthesia (MUA) at 6 weeks. This was revised to a cemented component and the patient is doing well 4 years later. A second patient experienced a patellar tendon rupture, later surgically repaired. Another patient sustained a patella fracture that was managed nonoperatively. The fracture healed by 1 year and the patient continued to have an otherwise successful outcome, now at 2 years follow-up. No progressive radiolucencies, subsidence, or changes in initial postoperative axial alignment were observed at final follow-up. The results from this study highlight a 98% success rate at mean 4.5 years follow-up in a large cohort of patients with a diverse spread of demographic details. Specific to the patella, only one patient experienced an adverse event, which was managed nonoperatively. Therefore, based on this data, patellar fixation in cementless TKA can be considered a safe technique.

This review investigated the potential value of computed tomography (CT) scans for the evaluation and management of knee arthritis and arthroplasty. Specifically, we evaluated the following: (1) assessment of arthritis within knee compartments, (2) patellofemoral joint assessment, (3) implant sizing prediction, (4) component alignment, (5) soft-tissue protection, and (6) potential concerns with radiation exposure. To compare if CT or X-ray imaging is more accurate and clinically relevant, a search was performed using Boolean search operators and terms: “CT,” “radiograph,” “joint alignment,” “knee,” and “arthroplasty,” which yielded 661 results. Studies were evaluated based on (1) assessment of arthritis within knee compartments, (2) patellofemoral joint assessment, (3) implant sizing prediction, (4) component alignment, (5) soft-tissue protection, and (6) potential concerns with radiation exposure. Correlative and comparative analyses of imaging modalities to pre-, intra-, and postoperative clinical and patient-related factors were performed for the 63 included studies. CT scans were found to better detect medial and lateral arthritic changes, bony deformities, subchondral cysts, and cartilage losses. CT scans were shown to 99% accurately predict prosthetic sizes preoperatively. CT scans can also help better visualize surrounding anatomy, such as the posterior cruciate ligament, and have therefore been linked to better soft tissue protection during total knee arthroplasty. Although radiation is a potential concern, newer imaging protocols have comparable exposure to plain radiographs. Compared with plain radiographs, CT scans were found to be more accurate and provide more clinically relevant data. Therefore, the authors recommend the use of CT for the evaluation of certain patients with arthritis and for preoperative planning for knee arthroplasty.

Total knee arthroplasty (TKA)-associated hemarthroses are infrequent and often respond to nonoperative therapy. Geniculate artery embolization may provide symptomatic relief in cases recalcitrant to needle aspiration, although no meta-analysis exists regarding this therapy. This meta-analysis aims to assess the rate of symptom relief, the number of embolizations needed to achieve relief, and the rate of complications associated with embolization. Public databases were queried from 1998 until 2018 for TKA-associated recurrent hemarthroses treated with embolization. Eight studies met inclusion and exclusion criteria. Major complications were defined as those requiring readmission or nonelective reoperation; minor complications were defined as those not requiring readmission or reoperation. Pooled statistics were calculated utilizing the method of inverse variance. Fifty-nine patients with a mean follow-up of 30 months (range, 1–50 months) were evaluated. The pooled proportion of patients with symptom improvement following embolization was 86% (95% confidence interval [CI]: 74–93%, I 2: 0%, p = 0.97). The average number of embolization procedures was 1.30 (95% CI: 1.03–1.63, I 2: 0%, p = 0.66). The pooled proportion of patients who required a second embolization procedure was 26% (95% CI: 15–40%, I 2: 0%, p = 0.43), while those requiring three or more procedures was 13% (95% CI: 6–25%, I 2: 0%, p = 0.87). The rate of complications were as follows: any complication – 19% (95% CI: 11–32%, I 2: 0%, p = 0.81); major complications–8% (95% CI: 3–19%, I 2: 0%, p = 0.96); minor complications–18% (95% CI: 10–31%, I 2: 0%, p = 0.79); inguinal hematoma–9% (95% CI: 4–19%, I 2: 0%, p = 1.00); skin necrosis–15% (95% CI: 7–29%, I 2: 0%, p = 0.62); and incision breakdown–7% (95% CI: 3–17%, I 2: 0%, p = 1.00). Previous literature on selective artery embolization following TKA is relatively limited. This meta-analysis supports embolization as a potentially safe and effective treatment for recurrent hemarthroses after TKA. Other correctable causes of recurrent hemarthrosis, such as instability or malalignment, must be diligently ruled out prior to utilizing embolization. Surgeons should be aware of embolization's potential role in the postoperative period following TKA.

Nutritional status has become increasingly important in optimizing surgical outcomes and preventing postoperative infection and wound complications. However, currently, there is a paucity in the orthopaedics literature investigating the relationship between nutritional status and wound complications following total knee arthroplasty (TKA). Therefore, the purpose of this study was to determine the prevalence of (1) postoperative infections, (2) wound complications, (3) concomitant infection with wound (CoIW) complication, and (4) infection followed by wound complication by using (1) albumin, (2) prealbumin, and (3) transferrin levels as indicators of nutritional status. These four different outcome measures were chosen as they are encountered commonly in daily clinical practice. A retrospective review of a national private payer database for patients who underwent TKA with postoperative infections and wound complications stratified by preoperative serum albumin (normal: 3.5–5 g/dL), prealbumin (normal: 16–35 mg/dL), and transferrin levels (normal: 200–360 mg/dL) between 2007 and 2015 was conducted. Patients were identified by Current Procedural Terminology (CPT), International Classification of Disease, ninth revision (ICD-9) codes, and Logical Observation Identifiers Names and Codes (LOINC). Linear regression was performed to evaluate changes over times. Yearly rates of infection, as well as a correlation and odds ratio analysis of nutritional laboratory values to postoperative complications, were also performed. Our query returned a total of 161,625 TKAs, of which 11,047 (7%) had postoperative wound complications, 18,403 (11%) had infections, 6,296 (34%) had CoIW, and 4,877 (4%) patients with infection developed wound complications. Albumin was the most commonly ordered laboratory test when assessing complications (96%). Wound complications, infections, CoIW, and infection with wound complications after were higher in those below the normal range: albumin

Substance abuse can have strong negative impacts on surgical outcomes. Therefore, this study assessed the effects of drug abuse in total knee arthroplasty (TKA) patients. Specifically, we identified revision TKA (RTKA): (1) incidence, (2) causes, (3) time to revision, and (4) patient demographics in patients with a history of drug abuse. The Medicare database within the PearlDiver Supercomputer (Warsaw, IN) was queried to identify 2,159,221 TKAs performed between 2005 and 2012. Drug abuse was subdivided into cocaine, cannabis, opioids, sedatives/hypnotics/anxiolytics (SHA), amphetamines, and alcohol abusers. The effect of drug use on the incidence and cause for RTKA, time to revision, as well as patient demographics were correlated using multivariate, analysis of variance, and regression analyses. There was a significant increase in the number of primary TKAs in cocaine (p = 0.011), cannabis (p

Despite the wide utilization of total knee arthroplasty (TKA), it can be technically challenging to perform in patients who have concomitant bone loss, ligamentous laxity, or high-grade deformity, whether in a revision situation or due to a primary pathology. Therefore, hinged knee prostheses have been developed to provide more stable fixation in these situations. The purpose of this study was to compare the short-term peri- and postoperative outcomes of patients undergoing primary TKA with and without hinged prosthesis. Specifically, we compared (1) mean operative times, (2) lengths of stay (LOS), (3) 30-day readmissions, and (4) complications. The American College of Surgeons National Surgical Quality Improvement Program database was queried to identify hinged TKAs and 99 procedures were included. They were matched in a 1:3 ratio to primary TKAs without a hinged prosthesis using propensity score matching. Operative time, LOS, discharge disposition, 30-day readmissions, and complications were compared. Adjusted odds ratios (OR) were also calculated. The operative time was significantly higher in hinged cohort compared with the nonhinged cohort (mean difference [MD] = 22 minutes; range, 10–34 minutes, p

Although several studies highlight the advantages of robotic arm-assisted total knee arthroplasty (RA-TKA), few investigate its intraoperative outcome. Therefore, the purpose of this study was to analyze the RA-TKA's ability to assist with intraoperative correction of: (1) flexion and (2) extension gaps, as well as its ability to (3) accurately predict implant sizes. Additionally, in this RA-TKA cohort, length of stay, complications, and readmissions were assessed. A total of 335 patients who underwent RA-TKA were included. The robotic software virtually measured the intraoperative prebone cut extension and flexion gaps. Differences in medial versus lateral prebone cut extension and flexion gaps were calculated. A total of 155 patients (46%) had an extension gap difference of between –2 and 2 mm (mean, –0.3 mm), while 119 patients (36%) had a flexion gap difference of between –2 and 2 mm (mean, –0.6 mm). Postbone cut differences in medial versus lateral flexion and extension gaps were measured. Balanced knees were considered to have a medial and lateral flexion gap difference within 2 mm. The robot-predicted implant size was also compared with the final implant size. Additionally, lengths of stay, complications, and readmissions were assessed. All patients achieved a postbone cut extension gap difference between –1 and 1 mm (mean, –0.1 mm). A total of 332 patients (99%) achieved a postbone cut flexion gap difference of between –2 and 2 mm (mean, 0 mm). For 98% of prostheses, the robotic software predicted within 1 implant size the actual tibial or femoral implant size used.The mean length of stay was found to be 2 days. No patients suffered from superficial skin infection, pin site infections or fractures, soft tissue damage, and no robotic cases were converted to manual TKA due to intraoperative complications. A total of 8 patients (2.2%) were readmitted; however, none were directly related to robotic use. The robotic software and use of a preoperative computed tomography (CT) substantially helped with intraoperative planning and accurate prediction of implant sizes. Therefore, based on the results of this study, the RA-TKA device does, in fact, provide considerable intraoperative assistance.

This study evaluated the use of telerehabilitation during the postoperative period for patients who underwent total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA). Specifically, this study evaluated the following: (1) patient compliance and adherence to the program, (2) time spent performing physical therapy exercises, (3) the usability of the virtual rehabilitation platform, and (4) clinical outcome scores in a selected primary knee arthroplasty cohort. A total of 157 consecutive patients underwent TKA (n = 18) or UKA (n = 139). These patients used a telerehabilitation system with an instructional avatar, three-dimensional motion measurement and analysis software, and real-time televisit capability designed for arthroplasty patients. Compliance was determined by how many times the patients followed prescribed repetitions of exercises. The total time spent performing exercises for each patient was collected. The usability of the virtual rehabilitation platform (on the patient's end) was evaluated using the system usability scale (SUS) questionnaire. The number of in-person and televisits was recorded for each patient. Patient-reported outcomes were collected through the patient and clinician interfaces and included the Knee Society Score (KSS) for pain and functions, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and Boston University Activity Measure for Post-Acute Care (AM-PAC) score. Patients spent an average of 29.5 days partaking in the therapy. TKA and UKA patients had a mean of 3.5 and 3.2 outpatient follow-up visits, each, for in-office therapy with a physical therapist, respectively. This figure exceeded the mean number of real-time virtual patient–clinician visits by 0.8 visits per patient in the TKA cohort and by 1 visit per patient in the UKA cohort. Patients spent on average 26.5 minutes per day conducting an average of 13.5 exercises. By the end of rehabilitation, patients had spent an average of 10.8 hours performing exercises, and of all the exercises performed, approximately 21 exercises were uniquely designed. Mean SUS score in the cohort was 93 points, which was interpreted as being above the 50th percentile point of the scale. Following therapy, KSS pain and function scores improved markedly and the improvements were measured at 368% for TKA and 350% for UKA (pain) and 27% for UKA and 33% for TKA (function). In addition, WOMAC scores improved by 57% and 66% for UKA and TKA patients while the improvement in AM-PAC scores was at 22% and 24%. This telerehabilitation platform encouraged clinician–patient interaction beyond the hospital setting and offers the advantage of cost savings, convenience, at-home monitoring, and coordination of care, all of which are geared to improve adherence and overall patient satisfaction. Additionally, the biometric data can be used to develop custom physical therapy regimens to assure proper rehabilitation, which is lacking in other telerehabilitation applications that use noninteractive videos that can be watched on mobile devices and tablets.

Knee pain is a highly prevalent condition in the United States with multiple etiologies, with two of the most common sources being osteoarthritis (OA) and patellofemoral pain (PFP). These conditions can lead to reduced physical function and a poor quality of life. Various modalities have been used to decrease the amount of knee pain that individuals' experience; however, they are not always successful and can be expensive. Several studies have reported on specialized footwear for symptomatic alleviation of conditions that affect the knee, this is because it has been theorized that certain footwear can alter the forces placed by muscles on lower-extremity joints, and can potentially alleviate pain by reducing the load placed on the joint. Therefore, the purpose of this study was to review the current literature on the use of various types of footwear used in patients who suffer from knee pain. Specifically, we evaluated: (1) knee OA and (2) PFP and the effect that different footwear has on patients' symptoms. Multiple different types of footwear and orthosis were utilized to treat patients with chronic knee pain. However, the results from reported outcomes by different studies are conflicting, which warrant further studies. Nevertheless, there are enough positive results to view this as a potential major modality to utilize for the treatment of knee OA.

As the use of disease modifying antirheumatic drugs have increased, it remains unclear whether or not this has affected the rates of total knee arthroplasty (TKA) in rheumatoid arthritis (RA) patients. Therefore, the purpose of this study was to evaluate the annual trends of RA patients who underwent TKA. Specifically, we evaluated: (1) the annual trends of TKAs due to RA in the United States population; and (2) the annual trends in the proportion of TKAs due to RA in the United States. The Nationwide Inpatient Sample was used to identify all patients who underwent TKA between 2002 and 2013 (n = 6,492,873). Then, we identified TKA patients who had a diagnosis of RA, defined by the International Classification of Diseases, Ninth Revision (ICD-9) code 714.0. The incidence of TKAs with a diagnosis of RA in the United States was calculated using the U.S. population as the denominator. Regression models were used to analyze the annual trends of RA in patients who underwent TKA. A total of 209,332 RA patients were identified who underwent TKA. The annual prevalence of RA in patients who underwent TKA slightly increased, from 33.2 per 1,000 TKAs in 2002 to 35 per 1,000 TKAs in 2013 (R 2 = 0.254, p = 0.095). The annual number of TKAs with a diagnosis of RA increased by 93.1% from 11,618 to 22,430. After normalizing for the U.S. population, the incidence of TKAs with RA increased from 5.4 to 9.2 TKAs per 1 million U.S. adults (incidence rate ratio [IRR] = 1.05; 95% confidence interval [CI], 1.05–1.05; p

Sagittal deformity of the knee is commonly corrected to neutral biomechanical axis (±3 degrees) during total knee arthroplasty (TKA), which is a widely accepted goal. Recent advances in surgical technology have made it possible to accurately plan and fulfill these goals. One of these is robotic-assisted TKA, which has been noted to help increase accuracy and precision of restoring a neutral mechanical axis. While there are data confirming the ability of robotic devices to better correct knee alignment than the manual technique, there is a lack of data concerning the use of the robotic devices in more complex cases, such as those in patients with severe varus or valgus deformity, as well as in flexion contractures. Therefore, the purpose of this case study is to present three cases in which the robotic-assisted TKA device was used to correct a severe varus and severe valgus deformities. Based on this case series, it should be noted that the robotic device can also help correct severe varus/valgus deformities and flexion contractures.

Several recent intraoperative and wound management techniques have been developed and implemented in the United States over the past decade; however, it is unclear what the effects of these newer modalities have on reducing surgical site infection (SSI) rates. Therefore, the purpose of this study was to track the annual rate and trends of (1) overall, (2) deep, and (3) superficial SSIs following revision total knee arthroplasty (TKA). The National Surgical Quality Improvement Program database was queried for all revision TKA cases performed between 2011 and 2016, which yielded 9,887 cases. Cases with superficial and/or deep SSIs were analyzed separately and then combined to evaluate overall SSI rates. After an overall 6-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with the preceding 5 years. Correlation coefficients and chi-square tests were used to determine correlation and statistical significance. No significant correlations between combined, deep, and/or superficial SSI rates and year were noted (p > 0.05). The lowest overall SSI incidence was in 2012 (1.16%), while the greatest incidence was in 2014 (1.76%). The deep SSI incidence over the 6 years was 0.67% (66 out of 9,887 cases). Deep SSI rate decreased by 10% in 2016 compared with 2011 (0.50 vs. 0.56%, p > 0.05). In this 6-year period, 94 cases out of 9,887 were complicated by a superficial SSI, an incidence of 0.95%. The lowest superficial SSI incidence occurred in 2015 (n = 17, 0.77%). Overall, the incidence of SSIs in revision TKA has remained fairly low with some annual variance, indicating room for improvement. These variations likely as revision surgeries can be more complex and have several associated confounding factors influencing outcomes, when compared with primary cases. Further research is needed to identify revision-specific strategies to reduce the risk of surgical site infections.

The effort to reduce overall healthcare costs may affect more complex patients, as their pre- and postoperative care can be substantially involved. Therefore, the purpose of this study was to use a large nationwide insurance database to compare (1) costs, (2) reimbursements, and (3) net losses of 90-day episodes of care (EOC) for total knee arthroplasty (TKA) patients according to Elixhauser's Comorbidity Index (ECI) scores. All TKAs performed between 2005 and 2014 in the Medicare Standard Analytic Files were extracted from the database and stratified based on ECI scores, ranging from 1 to 5. ECI 1 patients served as the control cohort, while ECI 2, 3, 4, and 5 patients were considered study cohorts. Each study cohort and control cohort were matched based on age and sex, resulting in a total of 715,398 patients included for analysis. Total EOC costs, reimbursements, and total net losses (defined as total EOC costs minus total EOC reimbursements) were compared between the cohorts. Overall, total EOC costs increased with ECI. For example, compared with the matched ECI 1 cohorts, the total EOC costs for ECI 5 patients ($56,589.19 vs. $51,747.54) were significantly greater (p

There are conflicting results regarding the impact of rheumatoid arthritis (RA) on total knee arthroplasty (TKA) outcomes. Therefore, the purpose of this study was to compare outcomes of patients with and without RA undergoing primary TKA. Specifically, we assessed (1) 90-day medical complications, (2) 90-day readmission rates, (3) short-term implant-related complications, (4) 1-year mortality, and (5) total global 90-day episode-of-care costs. The authors of the study hypothesize that RA would increase the rate of medical- and implant-related complications, readmission rates, and costs. A retrospective level of evidence III study was conducted using the Medicare standard analytical files from the PearlDiver database. Patients were queried using the International Classification of Disease, ninth revision codes. Patients with RA were randomly matched 1:1 to controls according to age, gender, and Charlson's comorbidity index. Two mutually exclusive cohorts were formed. Medical- and implant-related complications, readmission rates, and costs were analyzed and compared between the cohorts. Statistical analysis using logistic regression was performed calculating odds ratios (OR), 95% confidence intervals (95% CI), and their respective p-values. The query returned 102,898 patients with (n = 51,449) and without (n = 51,449) RA undergoing primary TKA within the Medicare database from 2005 to 2014. Patients with RA had greater odds of medical complications (OR: 2.08, 95% CI: 1.98–2.20, p

The purpose of this study was to perform a 3-month interim comparative analysis on outcomes between robotic-arm-assisted total knee arthroplasty (RATKA) and manual TKA patients. Specifically, we evaluated (1) patient self-reported symptoms, (2) expectations and satisfaction, and (3) functional activities, based on the 2011 Knee Society Scoring System. Between June 1, 2016, and March 31, 2018, 252 patients (102 manual and 150 robotic) were enrolled into a prospective, nonrandomized, open-label, multicenter comparative cohort study. Functional activity scores, patient-reported symptoms, as well as satisfaction and expectation scores were obtained from the 2011 Knee Society Scoring System preoperatively, at 4 to 6 weeks, and at 3 months postoperatively. Student's t-tests, Wilcoxon rank-sum tests, and chi-square tests with α set at 0.05 were used to compare between-group mean improvements from baseline. At 4 to 6 weeks postoperatively, RATKA patients were found to have significantly larger improvements in walking and standing (1.4 vs. –1.2 points; p = 0.019). RATKA patients were also found to have larger improvements in advanced activities (1.3 vs. 2.3 points), pain with walking (3.3 vs. 3.2 points), satisfaction score (12.4 vs. 12 points), and expectations score (5.1 vs. 4.4 points) when compared with manual TKA patients. At 3 months, RATKA patients were also found to have larger improvements in walking and standing (6.0 vs. 4.8 points), standard activities (11.4 vs. 10.1 points), advanced activities (6.2 vs. 4.6 points), functional activities total score (22.8 vs. 21.2 points), pain with walking (4.3 vs. 4.1 points), total symptoms score (10.5 vs. 10.3 points), satisfaction score (17.0 vs. 15.5 points), expectations score (4.8 vs. 4.0 points) when compared with manual TKA patients. The data indicate RATKA patients to have equal or greater improvements in 9 out of 10 of the Knee Society Scoring System components assessed at 3 months postoperatively, though not all findings were statistically significant. Since this is an early results report, this study will be continued for a longer follow-up, but we are encouraged by these interim results.

Although there are many studies on the alignment advantages when using the robotic arm–assisted (RAA) system for total knee arthroplasty (TKA), there have been questions regarding patient-reported outcomes. Therefore, the purpose of this study was to use this index to compare: (1) total, (2) physical function, and (3) pain scores for manual versus RAA patients. We compared 53 consecutive RAA to 53 consecutive manual TKAs. No differences in preoperative scores were found between the cohorts. Patients were administered a modified Western Ontario and McMaster Universities Osteoarthritis Index satisfaction survey preoperatively and at 1-year postoperatively. The results were broken down to: (1) total, (2) physical function, and (3) pain scores. Univariate analysis with independent samples t-tests was used to compare 1-year postoperative scores. Multivariate models with stepwise backward linear regression were utilized to evaluate the associations between scores and surgical technique, age, sex, as well as body mass index (BMI). Statistical analyses were performed with a p

Compared with nonelective total knee arthroplasties (TKAs), elective procedures have more time for preoperative planning, which allows for potentially improved patient optimization, risk factor modification, and patient education. The purpose of this study was to (1) determine nationwide trends in operative times and (2) evaluate associations between surgery type, elective or nonelective, with respect to (a) operative times, (b) length of stay (LOS), (c) discharge dispositions, (d) 30-day postoperative complications, (e) reoperations, and (f) readmissions. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for all primary TKAs performed between 2011 and 2016. This yielded 209,178 cases which were stratified into elective and nonelective cases. Elective cases were those in which patients were brought from their normal living environment for scheduled procedures. One-way ANOVA (analysis of variance) was used to evaluate associations between operative times and year of surgery. Multivariate linear and logistic regression models adjusted for surgery year and patient factors (age, sex, BMI [body mass index], and ASA [American Society of Anesthesiologists] score) were used to evaluate associations of surgery type with peri- and postoperative outcomes. A significant inverse correlation between operative times and operative year was observed (p

The ongoing debate on fixation in total knee arthroplasty (TKA) has become increasingly relevant with its increased use in a younger patient population and the advent of novel cementless prostheses. Recent literature suggests modern cementless implants are comparable to their cemented counterparts in terms of survivorship and functional outcomes. What has not been well-assessed is whether the two modalities differ with respect to infection rates which was the purpose of this study. Specifically, a propensity score matched study population was used to compare: (1) overall infection; (2) prosthetic joint infection (PJI); and (3) surgical site infection (SSI) rates between cementless and cemented TKAs. Using a large institutional database, 3,180 consecutive primary TKAs were identified. Cementless and cemented TKA patients were propensity score matched by age (p = 0.069), sex (p = 0.395), body mass index (BMI; p = 0.308), and Charlson's comorbidity index (CCI) score (p = 0.616) in a 1:1 ratio. Univariate analysis was performed to compare 2-year overall infection rates. Infections were further analyzed separately as PJIs (deep joint infections requiring surgery) and SSIs (skin/superficial wound infections). Multivariate logistic regression was performed to evaluate infection incidences after adjusting for procedure-related factors (i.e., operative time, hospital volume, and surgeon volume). There were no significant differences between the matched cohorts in terms of overall infection rates (3.8 vs. 2.3%, p = 0.722), as well as when PJI (p = 1.000) and SSI (p = 1.000) rates were analyzed separately. Multivariate analysis revealed no significant differences in overall postoperative infection rates (p = 0.285), PJI rates (p = 0.446), or SSI rates (p = 0.453) even after adjusting for procedure-related factors. There is increasing literature investigating various outcomes demonstrating the comparable efficacies of cementless versus cemented TKAs. To the best of the author's knowledge, this was the first matched case-control study to directly compare their post-operative infection rates. The findings from this study show that post-operative infection rates were similar between fixation modalities even after accounting for a range of patient- and procedure-related factors.

Morbid obesity is considered to have a stronger association with complications after total knee arthroplasty (TKA). Although the impact of obesity coding errors has been previously reported, the extent of coding inaccuracies with respect to morbid obesity is unclear. Therefore, the purpose of this study was to assess (1) the utility of coding in identifying morbid obesity and (2) the effects of morbid obesity on 90-day complications after TKA when morbid obesity was defined by both body mass index (BMI) and International Classification of Diseases 9th edition (ICD-9) coding. A total of 18,030 primary TKAs performed at a single institution from 2004 to 2014 were identified. Patients were defined as morbidly obese based on ICD-9 codes or by BMI recorded in the electronic medical record (EMR). Patients were defined as obese (ICD-9 codes 278.0, 278.00, 278.01, 278.03, 649.10–14, 793.91, V85.30–39, V85.41–45, V85.54) or morbidly obese (278.01, V85.41–45) by ICD-9 codes. Patient EMRs were also reviewed to identify obese and morbidly obese patients (BMI cutoffs of 30 and 40 kg/m2, respectively). Complications between the cohorts were compared. Sensitivity and specificity were also calculated. Among the 2,880 surgeries performed in morbidly obese patients, a code for obesity was present in 1,618 (56.2%) surgeries, but only 57.9% (937) of these patients had a code specific for morbid obesity, with the rest having a code not specifying morbid obesity. The sensitivity and specificity of obesity coding were 34.5 and 96.0%, while that of morbid obesity were 32.5 and 96.7%, respectively (area under curve: 0.65 vs. 0.65, p = 0.214). A higher rate of complications was noted when patients were defined as morbidly obese by ICD-9 as when defined by EMR-reported BMI. Although morbidly obese patients are more likely to have a code for obesity compared with obese patients, these patients may not be correctly identified as morbidly obese due to a lack of specificity in the codes. These errors may lead to inadequate reimbursements, and may also overestimate the effect of morbid obesity on complications.

This study determined if robotic-arm assisted total knee arthroplasty (RATKA) allows for more accurate and precise bone cuts and component position to plan compared with manual total knee arthroplasty (MTKA). Specifically, we assessed the following: (1) final bone cuts, (2) final component position, and (3) a potential learning curve for RATKA. On six cadaver specimens (12 knees), a MTKA and RATKA were performed on the left and right knees, respectively. Bone-cut and final-component positioning errors relative to preoperative plans were compared. Median errors and standard deviations (SDs) in the sagittal, coronal, and axial planes were compared. Median values of the absolute deviation from plan defined the accuracy to plan. SDs described the precision to plan. RATKA bone cuts were as or more accurate to plan based on nominal median values in 11 out of 12 measurements. RATKA bone cuts were more precise to plan in 8 out of 12 measurements (p ≤ 0.05). RATKA final component positions were as or more accurate to plan based on median values in five out of five measurements. RATKA final component positions were more precise to plan in four out of five measurements (p ≤ 0.05). Stacked error results from all cuts and implant positions for each specimen in procedural order showed that RATKA error was less than MTKA error. Although this study analyzed a small number of cadaver specimens, there were clear differences that separated these two groups. When compared with MTKA, RATKA demonstrated more accurate and precise bone cuts and implant positioning to plan.

Due to the paucity of evidence, this study was conducted to evaluate: (1) unique characteristics of multiple sclerosis (MS) patients and (2) short-term clinical outcomes, of primary total knee arthroplasty (TKA) in patients with MS (MS-TKA) compared with matched non-MS patients. MS patients who underwent TKA were identified using the Nationwide Inpatient Sample (NIS) database. The study sample consisted of 10,884 patients with MS and 56,45,227 control cohort. Various patient factors were compared. To control for potential confounders, with the use of propensity scores, MS-TKA patients were matched (1:3) to non-MS-TKA patients and regression analyses were performed to compare perioperative complications, length of stay (LOS), and discharge dispositions. Patients with MS were younger, more likely to be females, on corticosteroids, and more likely to have muscle spasms and gait abnormalities. Annual frequency of TKAs in MS patients increased from 1.16/1,000 TKAs in 2002 to 2.48/1,000 TKAs in 2013 (p

Postoperative pain remains difficult to control after total knee arthroplasty (TKA). While various modalities have been used, they have been associated with several side effects. For example, opioids have many side effects including: sedation, dizziness, nausea, vomiting, constipation, respiratory depression, and can lead to dependency. Recently, intravenous (IV) acetaminophen has been introduced as a method to manage postoperative pain. Therefore, the purpose of this study was to compare the postoperative outcomes of TKA patients who received oral acetaminophen versus IV acetaminophen. Specifically, this study evaluated: (1) the hospital lengths of stay (LOS) and (2) discharge dispositions. The Premier Database was used to review patients who underwent TKA from 2012 to 2015. A total of 134,216 TKA patients received oral acetaminophen, whereas 56,475 TKA patients received IV acetaminophen postoperatively. LOS were calculated as the number of days from the date of hospital admission to the date of discharge, and the discharge disposition was categorized as to home or to a skilled nursing facility (SNF). Compared with the oral group, the IV acetaminophen group had a 0.14 days shorter LOS (95% confidence interval [CI], –0.15 to –0.13; p

Although robotic-assisted total knee arthroplasty (TKA) has the potential to accurately reproduce neutral alignment, it is still unclear if this correction is attainable in patients who have severe varus or valgus deformities. Therefore, the purpose of this study was to assess a single surgeon's experience with correcting coronal deformities using the robotic-assisted TKA device. Specifically, we looked at correction of varying degrees of varus and valgus deformity in patients who underwent robotic arm-assisted TKA. A total of 330 robotic-assisted TKA cases performed by a single surgeon were analyzed. Preoperative CT scans were registered to the robotic-assisted software to create a three-dimensional rendering from which coronal alignment was measured. Postoperative coronal alignment measurements were taken in the operating room using the robotic-assisted device after trial component placement. The robotic-assisted device uses optical tracking from navigation probes placed on the distal femur and proximal tibia. The robotic-assisted software can register these probes as bony landmarks to measure coronal alignment in the distal plane of the femoral component and proximal plane of the tibial component. A total of 261 cases were of varus knees, 46 cases were of valgus knees, and 23 cases had 0° preoperative alignment. Severe deformity was defined as 7° or greater deformity. Preoperative neutral alignment was defined as 0°, while postoperative neutral alignment was defined as 0° ± 3°. There were 129 patients with and initial severe varus and 7 patients with an initial severe valgus deformity of 7° or greater. Patients were divided into varus or valgus cohorts, and analysis was performed on the overall cohort, as well as nonsevere (All 132 knees with initial varus deformity of less than 7° were corrected to neutral (mean 1°, range -1–3°). A total of 82 knees (64%) with 7° or greater varus deformity were corrected to neutral (mean 2°, range 0–3°). However, roughly 30% of patients with severe deformity who were not corrected to neutral were still corrected within a couple of degrees of neutral. There were seven knees with 7° or greater valgus deformity, and all were corrected to neutral (mean 2°, range 0–3°). This study demonstrated that all knees were corrected in the appropriate direction within a few degrees of neutral, and no knees were overcorrected. The implication of this ability to achieve alignment goals on clinical outcomes will need to be evaluated in future studies. The results from this study demonstrate the potential for the robotic-assisted device during TKA in helping surgeons achieve a preoperatively planned desired neutral alignment.

As with most new surgical technologies, there is an associated learning curve with robotic-assisted total knee arthroplasty (TKA) before surgeons can expect ease of use to be similar to that of manual cases. Therefore, the purpose of this study was to (1) assess robotic-assisted versus manual operative times of two joint reconstructive surgeons separately as well as (2) find an overall learning curve. A total of 240 robotic-assisted TKAs performed by two board-certified surgeons were analyzed. The cases were sequentially grouped into 20 cases and a learning curve was created based on mean operative times. For each surgeon, mean operative times for their first 20 and last 20 robotic-assisted cases were compared with 20 randomly selected manual cases performed by that surgeon as controls prior to the initiation of the robotic-assisted cases. Each of the surgeons first 20 robotic assisted, last 20 robotic assisted, and 20 controls were then combined to create 3 cohorts of 40 cases for analysis. Surgeon 1: First and last robotic cohort operative times were 81 and 70 minutes (p 0.05). Surgeon 2: First and last robotic cohort operative times were 117 and 98 minutes (p 0.05). A similar trend occurred when the times of two surgeons were combined. The data from this study effectively create a learning curve for the use of robotic-assisted TKA. As both surgeons completed their total cases numbers within similar time frames, these data imply that within a few months, a board-certified orthopaedic joint arthroplasty surgeon should be able to adequately perform robotic TKA without adding any operative times.

Study areas concerning maximizing knee range of motion (ROM) following total knee arthroplasty (TKA) have come under focus by surgeons. Among the perioperative factors that were identified to affect ROM after TKAs is knee position during surgical wound closure. Therefore, the aim of this study was to review the impact of knee position during TKA wound closure on: (1) postoperative ROM, (2) wound-related complications, (3) Knee Society Score (KSS), (4) postoperative pain, and (5) muscle strength and home functional recovery. A literature search was performed using PubMed, Ovid, and Google Scholar using various combinations of the following search terms: “wound closure,” “knee position,” “surgical closure,” and “knee arthroplasty.” The studies were evaluated for outcomes after TKA and stratified based on the knee position at surgical closure. After application of inclusion and exclusion criteria, seven studies were analyzed. The total number of patients included was 516 patients (259 patients in the flexion group and 257 patients in the full extension group). Based on the reviewed literature, wound closure in flexion was associated with significant improvement in ROM recovery at earlier follow-ups after TKA (four positive and three neutral studies), better early postoperative pain scores (two positive and one neutral study), and faster physical recovery (two positive studies) (better muscle strength and early achievement of physical therapy milestones) compared with wound closure in extension. No difference was found between wound closure in flexion compared with closure in extension in terms of long-term ROM recovery, long-term postoperative pain scores, wound-related complications (seven neutral studies), knee function measured by KSS (five neutral studies), or patient satisfactions after TKA. Although the current review is limited by the number of studies that are available in the literature, it demonstrates that overall, compared with extension, surgical wound closure in flexion may provide better ROM, faster recovery, comparable patient satisfaction, and no risk of higher wound complications.

Robotic arm-assisted total knee arthroplasty (RATKA) presents a potential, new added value for orthopedic surgeons. In today's health care system, a major determinant of value can be assessed by patient satisfaction scores. Therefore, the purpose of the study was to analyze patient satisfaction outcomes between RATKA and manual total knee arthroplasty (TKA). Specifically, we used the Western Ontario and McMaster Universities Arthritis Index (WOMAC) to compare (1) pain scores, (2) physical function scores, and (3) total patient satisfaction outcomes in manual and RATKA patients at 6 months postoperatively. In this study, 28 cemented RATKAs performed by a single orthopedic surgeon at a high-volume institution were analyzed. The first 7 days were considered as an adjustment period along the learning curve. Twenty consecutive cemented RATKAs were matched and compared with 20 consecutive cemented manual TKAs performed immediately. Patients were administered a WOMAC satisfaction survey at 6 months postoperatively. Satisfaction scores between the two cohorts were compared and the data were analyzed using Student's t-tests. A p-value