Advanced Concepts in Outpatient Joint Arthroplasty.

As the adoption and utilization of outpatient total joint arthroplasty continues to grow, key developments have enabled surgeons to safely and effectively perform these surgeries while increasing patient satisfaction and operating room efficiency. Here, the authors will discuss the evidence-based principles that have guided this paradigm shift in joint arthroplasty surgery, as well as practical methods for selecting appropriate candidates and optimizing perioperative care. There will be 5 core efficiency principles reviewed that can be used to improve organizational management, streamline workflow, and overcome barriers in the ambulatory surgery center. Finally, future directions in outpatient surgery at the ASC, including the merits of implementing robot assistance and computer navigation, as well as expanding indications for revision surgeries, will be debated.

Increasing the Volume of Outpatient Total Joint Arthroplasty Procedures: An Evaluation of a Novel Rapid Recovery Pathway Program Within an Academic Medical Center.

Background: There has been a national trend toward shifting joint arthroplasty procedures to the outpatient setting. These cases are often performed in freestanding ambulatory surgery centers (ASCs), which are often not accessible to surgeons within academic practices. Purposes: We sought to investigate a novel rapid recovery program used to transition arthroplasty patients to an outpatient-based care system within an academic medical center. Methods: All patients undergoing hip or knee arthroplasty between November 2019 and April 2021 were retrospectively evaluated for their eligibility for a rapid recovery pathway through the Extended Stay Unit (ESU) based on clinical and social criteria. Once admitted, patients were evaluated for whether they were discharged from the unit or if hospital admission was necessary. Results: Out of the 444 patients deemed candidates for the rapid recovery program, 188 patients were admitted to the ESU (42.3%); 18 (9.6%) required inpatient hospital admission, with the majority of these due to failing physical therapy (16; 88.9%). Of the ESU patients who were successfully discharged home, 55 (32.4%) were discharged on postoperative day (POD) 0 and 115 (67.6%) on POD 1 (<23 hours). Conclusion: As total joint arthroplasties shift toward the outpatient setting, surgeons in academic institutions must employ strategies to increase their volume of patient candidates for outpatient procedures. Our retrospective study of prospectively collected data suggests the feasibility of creating a separate rapid recovery unit within the hospital that can be an effective method by which to eventually transition to the ASC setting.

Social Risk Determinants for Successful Same Calendar Day Discharge in Total Joint Arthroplasty.

Background: While many studies have examined the impact of comorbidities on the success of same calendar day discharge (SCDD) in total joint arthroplasty (TJA), literature surrounding the impact of social determinants is lacking. Purpose: We sought to investigate the relationship between various social determinants and success of SCDD after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods: We conducted a retrospective review of 1160 THA and 1813 TKA performed at a single academic institution between November 2020 and August 2022. Social factors including substance use, occupation, marital status, income, and participation in physical exercise were included. In addition, aspects of discharge planning were reviewed such as living situation and transportation details. Results: Overall, 952 (32%) patients had successful SCDD, whereas 2021 (68%) patients were discharged on postoperative day 1 (POD1) or greater. Successful SCDD patients were more likely to have health care (4.8% vs 2.5%) and active (5.4% vs 4.6%) rather than sedentary occupations, be married (79.6% vs 67.4%), have access to transportation (95.6% vs 92.9%), live in a higher median income area ($64,044 [16,183] vs $61,572 [14,594]), and exercise weekly (62.6% vs 23.9%). Interestingly, the successful patients had more stories in their homes (1.62 [0.56] vs 1.43 [0.53]), more stairs to enter their homes (5.19 [5.22] vs 4.60 [5.24]), lived farther from the hospital (43.3 [138.0] vs 32.0 [75.9] miles), and a higher prevalence of alcohol use (60.7% vs 44.7%) and tobacco use (19.3% vs 17.3%). Conclusion: These findings may help arthroplasty surgeons to better understand the social factors that contribute to successful SCDD in TJA patients, ultimately aiding in patient selection and preoperative counseling.

The Use of Plant-Based Polysaccharide (PSP) Agents May Improve Early Outcomes Following Total Knee Arthroplasty-A Proof-of-Concept Study.

Our study sought to investigate the effects of a topical plant-based polysaccharide (PSP) as an adjunctive hemostat to minimize blood loss and improve early clinical outcomes in patients undergoing primary TKA. In this multi-center and randomized proof-of-concept study, 61 patients undergoing TKA were randomly assigned to one of two groups: A) intraoperative utilization of PSP (n=31) or B) no intervention (n=30). The primary outcomes were blood loss and change in hemoglobin, measured preoperatively and 24 hours postoperatively. Other endpoints included postoperative complications, Knee Society Score (KSS), knee range of motion (ROM), and thigh circumference. There was no difference in postoperative change of hemoglobin or calculated blood loss between the PSP and control groups. The PSP group achieved elevated flexion at two weeks (100.1° vs. 86.6°, p<0.05) and better change in KSS from preop to 90 days (29.5 vs. 22.4, p<0.05) than the controls. Some early postoperative outcomes were improved, which suggests a potential benefit of using PSP in primary TKA. However, the clinical significance of these differences warrants further investigation in a larger randomized trial.

Risk factors for blood transfusion and postoperative anaemia following total knee arthroplasty.

Aims: Blood transfusion and postoperative anaemia are complications of total knee arthroplasty (TKA) that are associated with substantial healthcare costs, morbidity, and mortality. There are few data from large datasets on the risk factors for these complications. Methods: We retrospectively reviewed the records of TKA patients from a single tertiary care institution from February 2016 to December 2020. There were a total of 14,901 patients in this cohort with a mean age of 67.9 years (SD 9.2), and 5,575 patients (37.4%) were male. Outcomes included perioperative blood transfusion and postoperative anaemia, defined a priori as haemoglobin level < 10 g/dl measured on the first day postoperatively. In order to establish a preoperative haemoglobin cutoff, we investigated a preoperative haemoglobin level that would limit transfusion likelihood to ≤ 1% (13 g/dl) and postoperative anaemia likelihood to 4.1%. Risk factors were assessed through multivariable Poisson regression modelling with robust error variance. Results: In multivariable analyses, each gram of tranexamic acid reduced transfusion likelihood by 39% (adjusted risk ratio (ARR) 0.61 (95% confidence interval (CI) 0.47 to 0.78)). Risk factors associated with an increased risk of transfusion included operating time (ARR 2.07 (95% CI 1.54 to 2.77)) and drain use (ARR 1.73 (95% CI 1.34 to 2.24)). Conclusion: In this study, we found that increased tranexamic acid dosing, decreased operating time, and decreased drain use may reduce transfusions following TKA. We also established a single preoperative haemoglobin cutoff of 13 g/dl that could help minimize transfusions and reduce postoperative complete blood counts.

Referencing the center of the femoral head during robotic or computer-navigated primary total knee arthroplasty results in less femoral component flexion than the traditional intramedullary axis.

BACKGROUND: During robotic and computer-navigated primary total knee arthroplasty (TKA), the center of the femoral head is utilized as the proximal reference point for femoral component position rather than the intramedullary axis. We sought to analyze the effect on femoral component flexion-extension position between these two reference points. METHODS: We obtained CT 3D-reconstructions of 50 cadaveric intact femurs. We defined the navigation axis as the line from center of the femoral head to center of the knee (lowest point of the trochlear groove) and the intramedullary axis as the line from center of the knee to center of the canal at the isthmus. Differences between these axes in the sagittal plane were measured. Degree of femoral bow and femoral neck anteversion were correlated with the differences between the two femoral axes. RESULTS: On average, the navigated axis was 1.4° (range, -1.4° to 4.1°) posterior to the intramedullary axis. As such, the femoral component would have on average 1.4° less flexion compared with techniques referencing the intramedullary canal. A more anterior intramedullary compared with navigated axis (i.e., less femoral flexion) was associated with more femoral bow (R2 = 0.7, P < 0.001) and less femoral neck anteversion (R2 = 0.5, P < 0.05). CONCLUSION: Computer-navigated or robotic TKA in which the center of the femoral head is utilized as a reference point, results in 1.4° less femoral component flexion than would be achieved by referencing the intramedullary canal. Surgeons should be aware of these differences as they may ultimately influence knee kinematics.

High degree of alignment precision associated with total knee arthroplasty performed using a surgical robot or handheld navigation.

PURPOSE: The purpose of this study was to compare the precision of bony resections during total knee arthroplasty (TKA) performed using different computer-assisted technologies. METHODS: Patients who underwent a primary TKA using an imageless accelerometer-based handheld navigation system (KneeAlign2®, OrthAlign Inc.) or computed tomography-based large-console surgical robot (Mako®, Stryker Corp.) from 2017 to 2020 were retrospectively reviewed. Templated alignment targets and demographic data were collected. Coronal plane alignment of the femoral and tibial components and tibial slope were measured on postoperative radiographs. Patients with excessive flexion or rotation preventing accurate measurement were excluded. RESULTS: A total of 240 patients who underwent TKA using either a handheld (n = 120) or robotic (n = 120) system were included. There were no statistically significant differences in age, sex, and BMI between groups. A small but statistically significant difference in the precision of the distal femoral resection was observed between the handheld and robotic cohorts (1.5° vs. 1.1° difference between templated and measured alignments, p = 0.024), though this is likely clinically insignificant. There were no significant differences in the precision of the tibial resection between the handheld and robotic groups (coronal plane 0.9° vs. 1.0°, n.s.; sagittal plane 1.2° vs. 1.1°, n.s.). There were no significant differences in the rate of overall precision between cohorts (n.s.). CONCLUSIONS: A high degree of component alignment precision was observed for both imageless handheld navigation and CT-based robotic cohorts. Surgeons considering options for computer-assisted TKA should take other important factors, including surgical principles, templating software, ligament balancing, intraoperative adjustability, equipment logistics, and cost, into account. LEVEL OF EVIDENCE: III.

The Risk Assessment and Prediction Tool (RAPT) Score Predicts Discharge Destination, Length of Stay, and Postoperative Mobility After Total Joint Arthroplasty.

BACKGROUND: Predicting an arthroplasty patient's discharge disposition, length of stay (LOS), and physical function is helpful because it allows for preoperative patient optimization, expectation management, and discharge planning. The goal of this study was to evaluate the ability of the Risk Assessment and Prediction Tool (RAPT) score to predict discharge destination, LOS, and postoperative mobility in patients undergoing primary total knee arthroplasty (TKA) and total hip arthroplasty (THA). METHODS: Primary unilateral TKAs (n = 9,064) and THAs (n = 8,649) performed for primary osteoarthritis at our institution from 2018 to 2021 (excluding March to June 2020) were identified using a prospectively maintained institutional registry. We evaluated the associations between preoperative RAPT score and (1) discharge destination, (2) LOS, and postoperative mobility as measured by (3) successful ambulation on the day of surgery and (4) Activity Measure for Post-Acute Care (AM-PAC) "6-Clicks" score. RESULTS: On multivariable analyses adjusting for multiple covariates, every one-point increase in RAPT score among TKA patients was associated with a 1.82-fold increased odds of home discharge (P < .001), 0.22 days shorter LOS (P < .001), 1.13-fold increased odds of ambulating on postoperative day 0 (P < .001), and 0.25-point higher Activity Measure for Post-Acute Care score (P < .001). Similar findings were seen among THAs. A RAPT score of 8 or higher was the most sensitive and specific cutoff to predict home discharge. CONCLUSION: Among nearly 18,000 TKA and THA patients, RAPT score was predictive of discharge disposition, LOS, and postoperative mobility. A RAPT score of 8 or higher was the most sensitive and specific cutoff to predict discharge to home. In contrast to prior studies of the RAPT score which have grouped TKAs and THAs together, this study ran separate analyses for TKAs and THAs and found that THA patients seemed to perform better than TKA patients with equal RAPT scores, suggesting that RAPT may behave differently between TKAs and THAs, particularly in the intermediate risk RAPT range.

Clinical and Biomechanical Characteristics of Posterior-Stabilized Polyethylene Post Fractures in Total Knee Arthroplasty: A Retrieval Analysis.

BACKGROUND: Fractures of the polyethylene post are a rare but known complication after posterior-stabilized (PS) total knee arthroplasty (TKA). We evaluated the polyethylene and patient characteristics for 33 primary PS polyethylene components that were revised with fractured posts. METHODS: We identified 33 PS inserts revised between 2015 and 2022. Patient characteristics collected included age at index TKA, sex, body mass index, length of implantation (LOI), and patient-reported details on events surrounding the post fracture. Implant characteristics recorded were manufacturer, cross-linking properties (highly cross-linked polyethylene [XLPE] versus ultra-high molecular weight polyethylene [UHMWPE]), wear characteristics based on subjective scoring of the articular surfaces and scanning electron microscopy (SEM) of fracture surfaces. Mean age at index surgery was 55 years (range, 35 to 69), mean body mass index was 29.5 (range, 18.5 to 37.2), and mean LOI was 10.0 (range, 4 to 26). RESULTS: Total surface damage scores were significantly higher in the UHMWPE group versus the XLPE group (57.3 versus 44.2, P = .003). SEM demonstrated fracture initiation at the posterior edge of the post in 10 of 13 cases. UHMWPE fracture surfaces posts had more tufted, irregularly clamshell features, while XLPE posts had more precise clamshell marking and a diamond pattern in the region of acute, final fracture. CONCLUSION: Characteristics of PS post fracture differed between XLPE and UHMWPE implants, with fractures occurring in the XLPE with less generalized surface damage, after a shorter LOI, and with SEM evaluation indicative of a more brittle fracture pattern.

Does a Uni "Feel Better" than a Total Knee? Not Necessarily, When Using Modern Implant Designs.

Background: When comparing functional outcomes of patients with unicompartmental knee arthroplasty (UKA) versus total knee arthroplasty (TKA), studies often report the UKA as the preferred procedure; however, recent improvements in the design of modern TKA implants have aimed at narrowing this gap. Purpose: We sought to compare the "feel" of modern TKA implants to that of UKA, using the Forgotten Joint Score (FJS), a validated patient-reported outcome measure. Methods: We performed a retrospective review of patients who underwent TKA and UKA at 2 institutions between 2014 and 2017. All UKA procedures were robotic arm-assisted with a single implant, "traditional TKAs" were performed using traditional posterior-stabilized implants, and "modern TKAs" were performed using posterior-stabilized implants with a modern design. Differences in FJS were assessed using 1-way analysis of variance and independent 2-sample t tests. Results: A total of 600 patients were included in our study, with 200 patients in each surgical subcategory. Mean age was 62.8 ± 10.2 years and mean body mass index was 29.9 ± 4.9. Modern TKA and UKA had similar FJS at 1 year. While modern TKA had a significantly higher FJS than traditional TKA, UKA did not have a significantly higher FJS than traditional TKA. Conclusion: Our retrospective analysis found no significant differences in the FJS of patients who underwent UKA and TKA with a modern design; however, both had superior scores than traditional TKA designs. This finding suggests that modern TKA designs may have the potential to achieve the natural feeling that is typically associated with joint-conserving surgeries such as UKA, although longer follow-up is necessary.

Patient perceptions of pain management and opioid use prior to hip arthroplasty.

OBJECTIVE: Qualitative assessment investigating patients' perceptions related to opioids including their role in pain control, risks, and handling and disposal prior to undergoing hip replacement. DESIGN: A prospective, cross-sectional survey study. SETTING: Large urban teaching hospital specializing in orthopedic surgery affiliated with Weill Cornell Medical College. PARTICIPANTS: Patients aged 18-80, English-speaking, without recent or chronic opioid use, and planning to undergo primary total hip replacement. A total of 128 patients were enrolled and completed the study. INTERVENTION: A 27-item interview evaluating perceptions on opioid-related -topics. MAIN OUTCOME MEASURES: Responses to interview questions were documented by research assistant. RESULTS: Most patients believe that there should be minimal or no pain with the use of opioids, though they also agree that opioids should be limited to pain that interferes with function or activity. Patients generally appreciate risks of addiction with opioids but are less familiar with risks associated with sleep apnea and sedatives. Minority of patients understand that the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in combination with opioids would effectively reduce pain. Majority of patients were unsure of how to properly store and dispose of opioids. CONCLUSIONS: Qualitative assessment demonstrates that patients may benefit from education and discussion specifically about pain expectations, the role of opioids in treating pain, multimodal analgesia, and proper storage and disposal.

Predicting Postoperative Anemia and Blood Transfusion Following Total Knee Arthroplasty.

BACKGROUND: While transfusion and clinically relevant anemia after elective primary total knee arthroplasty (TKA) are uncommon, there remains a question of who needs postoperative hemoglobin monitoring, especially in the setting of increasing incidence of outpatient TKA. The purpose of this study was to create predictive models for postoperative anemia and blood transfusion to guide clinical decision-making. METHODS: The records of consecutive TKA patients were reviewed from February 2016 to December 2020 at a single institution. Two multivariable logistic regression models, for postoperative anemia (hemoglobin < 10 g/dL) and allogeneic blood transfusion included 8 variables: age, sex, body mass index, preoperative hemoglobin level, tranexamic acid total dose, American Society of Anesthesiologists level, operative time, and drain use. Model performance was assessed using accuracy, area under the curve (AUC), sensitivity, and specificity. RESULTS: The records of 14,901 patients were included in this study. Patients had a mean (± standard deviation) age of 67.9 ± 9.2 years and mean body mass index of 31.3 ± 6.5 kg/m2. The postoperative anemia model had an accuracy of 88% (95% confidence interval [CI], 87%-89%) and AUC of 0.88 (95% CI, 0.87-0.89). The blood transfusion model had an accuracy of 97% (95% CI, 96%-97%) and AUC of 0.90 (95% CI, 0.87-0.93). CONCLUSION: The postoperative anemia and blood transfusion model accurately predicted each outcome. Patients with less than a 5% probability of postoperative anemia may not benefit from a complete blood count at postoperative day 1. Application of these criteria may save the healthcare system hundreds of millions of dollars. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Orthopaedics in the Real World: The Business and Legal Aspects of Employment in 2022.

As more physicians enter hospital employment on completion of their training, the details and complexity associated with these arrangements are increasing. To better position surgeons to succeed in any employment model, it is important to describe several key topics associated with these business models. First, financial modeling can be used to make smarter choices when evaluating employment opportunities. This tool, applied often in the business world, allows surgeons to truly understand the midterm and long-term financial implications of employment decisions and can help surgeons thrive financially as they progress through their careers. There are both positive and negative intricate points associated with different employment models, including hospital-employed positions. Although each model may have its minor unique differences, a thorough understanding of the basics is critical for success. Contracts and some of the common issues of concern that surgeons should be keenly aware of when negotiating their hospital employment contract are important topics for discussion, along with the concept of ancillary revenue, specifically its unique implications as it applies to hospital-employed physicians; these relationships can be very different from traditional private practice models of ancillary income. Orthopaedic surgeons should be knowledgeable about Stark Law, the Anti-Kickback Statute, and Certificate of Need laws and the potential effect of these and other regulations on physicians.

A Systematic Approach to Revision Total Knee Arthroplasty.

With the recent increase in primary total knee arthroplasties and the associated rise in failures of the index operation, there has been growing demand for orthopaedic surgeons to perform revision procedures. The orthopaedic surgeon performing revision total knee arthroplasty should be knowledgeable about the various etiologies of primary total knee arthroplasty failure, the steps for proper patient evaluation, and important factors in the preoperative planning process. A systematic methodology for obtaining surgical exposure, strategies for reconstruction, fundamentals of soft-tissue closure, and postoperative care also should be reviewed.

Reasons and Risk Factors for Failed Same-Day Discharge After Primary Total Knee Arthroplasty.

BACKGROUND: As ambulatory total knee arthroplasty (TKA) becomes increasingly common, unplanned admission after surgery presents a challenge for the health care system. Studies evaluating the reasons and risk factors for this occurrence are limited. We sought to evaluate the reasons for unplanned admission after surgery and identify risk factors associated with this occurrence. METHODS: Patients registered in an institutional ambulatory joint arthroplasty program who underwent a TKA from 2017-2020 were retrospectively reviewed. The criteria for enrollment include candidates for unilateral TKA between the ages of 18 and 70 years, with a body mass index (BMI) of less than 35, and appropriate social and material support at home. Patients who had certain comorbidities including coronary artery disease, valvular heart disease, and opioid dependence were not eligible. A total of 274 patients who underwent TKA with planned same-day discharge (SDD) were identified in the medical record and reviewed. In this cohort, 140 patients (51.1%) were discharged on the day of surgery and 134 patients (48.9%) required a minimum 1-night admission. Demographics, comorbidities, and perioperative data were collected. Factors associated with failed SDD were identified using multivariate logistic regression. RESULTS: The most common reasons for failed SDD were failure to meet ambulation goals (25%) and logistical issues related to a late-day case (19%). Risk factors for failed SDD include general anesthesia (odds ratio (OR) 12.60, P = .047), procedure start time after 11:00 am (OR 5.16, P < .001), highest postoperative pain score >8 (visual analogue scale, OR 5.78, P = .001). Willingness to accept a higher pain threshold before discharge (visual analogue scale 4 to 10) was associated with successful SDD (OR 3.0, P < .001). Age and American Society of Anesthesiologists (ASA) classification were not associated with failed SDD. CONCLUSIONS: The most common reasons for failed SDD were related to logistical issues and postoperative mobilization. Risk factors for failed SDD involve case timing and pain control. Modifiable perioperative factors may play an important role in successful SDD after TKA.

Same-Day Discharge Total Knee Arthroplasty in Octogenarians.

BACKGROUND: One of the most important aspects of the transition to outpatient (OP) arthroplasty is patient selection, with guidance traditionally recommending that OP total knee arthroplasty (TKA) be reserved for patients <80 years old. However, there are limited data as to whether older age should really be considered a contraindication to OP-TKA. The purpose of this study is to assess the risk of complications and readmissions following OP-TKA in patients ≥80 years old. METHODS: This is a retrospective, propensity-matched cohort study of the National Surgical Quality Improvement Program database from 2011 to 2019. Patients ≥80 years undergoing OP (same-day discharge) TKA were propensity matched to patients ≥80 years undergoing inpatient (IP) TKA based on age, gender, race, body mass index, American Society of Anesthesiologists classification, functional status, smoking status, anesthetic type, and medical comorbidities. There were 1,418 patients (709 IPs and 709 OPs) included. All baseline factors were successfully matched between IP-TKA versus OP-TKA (P ≥ .18 for all). Thirty-day complications, readmissions, reoperations, and mortality were subsequently analyzed. RESULTS: Thirty-day readmission rates were identical between patients undergoing IP-TKA and OP-TKA (3.5% versus 3.5%, P = 1.0). Similarly, there was no significant difference in the incidence of major complications (2.7% versus 2.0%, P = .38), reoperations (1.3% versus 0.8%, P = .44), or mortalities (0.3% versus 0.3%, P = 1.0) within 30 days. CONCLUSION: Octogenarians undergoing OP-TKA had comparable complication rates to similar patients undergoing IP-TKA. OP-TKA can be performed safely in select octogenarians and age ≥80 years likely does not need to be a uniform contraindication to OP-TKA.

Ambulatory total hip arthroplasty: Causes for failure to launch and associated risk factors.

AIMS: The volume of ambulatory total hip arthroplasty (THA) procedures is increasing due to the emphasis on value-based care. The purpose of the study is to identify the causes for failed same-day discharge (SDD) and perioperative factors leading to failed SDD. METHODS: This retrospective cohort study followed pre-selected patients for SDD THA from 1 August 2018 to 31 December 2020. Inclusion criteria were patients undergoing unilateral THA with appropriate social support, age 18 to 75 years, and BMI < 37 kg/m2. Patients with opioid dependence, coronary artery disease, and valvular heart disease were excluded. Demographics, comorbidities, and perioperative data were collected from the electronic medical records. Possible risk factors for failed SDD were identified using multivariate logistic regression. RESULTS: In all, 278 patients were identified with a mean age of 57.1 years (SD 8.1) and a mean BMI of 27.3 kg/m2 (SD 4.5). A total of 96 patients failed SDD, with the most common reasons being failure to clear physical therapy (26%), dizziness (22%), and postoperative nausea and vomiting (11%). Risk factors associated with failed SDD included smokers (odds ratio (OR) 6.24; p = 0.009), a maximum postoperative pain score > 8 (OR 4.76; p = 0.004), and procedures starting after 11 am (OR 2.28; p = 0.015). A higher postoperative tolerable pain goal (numerical rating scale 4 to 10) was found to be associated with successful SDD (OR 2.7; p = 0.001). Age, BMI, surgical approach, American Society of Anesthesiologists grade, and anaesthesia type were not associated with failed SDD. CONCLUSION: SDD is a safe and viable option for pre-selected patients interested in rapid recovery THA. The most common causes for failure to launch were failing to clear physical thereapy and patient symptomatology. Risk factors associated with failed SSD highlight the importance of preoperative counselling regarding smoking cessation and postoperative pain to set reasonable expectations. Future interventions should aim to improve patient postoperative mobilization, pain control, and decrease symptomatology.Cite this article: Bone Jt Open 2022;3(9):684-691.

Do obese patients benefit from a kinematic, appropriately designed total knee prosthesis?

Introduction: Modern total knee arthroplasty (TKA) using the Journey 2 implant utilizes a bicruciate stabilized (BCS) technique. However, whether bicruciate stabilized TKA is equally effective across weight classes is unknown. Methods: We identified patients who underwent primary bicruciate stabilized TKA during 2016 and 2017, at a single institution. All included patients had, at minimum, 2-year follow-up. Patients were categorized into body-mass index (BMI) groups as follows: underweight, normal, or overweight (<30 kg/m2), obese (≥30 to <35 kg/m2), and severely obese (≥35 kg/m2). Patient reported outcome measures (PROMs) were measured at baseline. Both KSS and KOOS JR, along with the Visual Analogue Scale (VAS), were also recorded at follow-up. Pre-operative, post-operative, and pre-to post-operative changes in PROMs were analyzed using analysis of variance (ANOVA) and linear regression. Results: The 292 patients had a mean age of 64.8 years and mean BMI of 32.3 kg/m2. There were 116 (39.7%) patients in the underweight, normal, or overweight group, 88 (30.1%) in the obese category, and 88 (30.1%) in the severely obese group. There were no differences between PROMs at baseline or at follow-up (p > 0.10 for all comparisons). There were also no differences in the improvement from pre-to post-operative KSS (p = 0.21) and KOOS JR (p = 0.62). Conclusions: Bicruciate stabilized TKA has similar effects on PROMs across BMI groups. These results suggest that bicruciate stabilized TKA is a viable treatment option both for low-weight and high-weight patients.