Leveraging Artificial Intelligence and Digital Health to Address Health-Related Social Needs and Optimize Risk-Based Value in Orthopaedic Surgery.

As the health care landscape evolves toward value-based care and emphasizes health-related social needs, the importance of developing health policies and digital health solutions that foster health equity and risk-based reimbursement strategies has grown. Orthopaedic surgery, catering to a diverse patient population but challenged by a lack of workforce diversity, encounters distinct opportunities and obstacles in adopting digital health technologies for delivering equitable, high-value care. The integration of health-related social needs into the emerging value-based care model and risk-based reimbursement policies is important. Furthermore, the potential of incorporating robust artificial intelligence governance and big data analytics to enhance patient outcomes and support orthopaedic surgeons in treating their patient populations should be studied. There are crucial considerations for creating comprehensive digital health platforms tailored for orthopaedic surgery, and the significance of specialty-specific advocacy and collaboration among clinicians, policymakers, and MedTech companies cannot be understated.

Outcomes of Total Knee Arthroplasty in Patients Who Have Ehlers-Danlos Syndrome: A Matched Cohort Study.

BACKGROUND: Total knee arthroplasty (TKA) is an excellent surgical option for patients who have end-stage knee osteoarthritis. While rates of major postoperative complications have steadily decreased with modern implants and operative techniques, contemporary outcome data for patients who have Ehlers-Danlos syndrome (EDS) are scarce. The goal of this study was to compare complication rates after primary TKA in patients who have EDS versus matched controls. METHODS: A large administrative database was used to identify patients who underwent primary TKA from 2009 to 2020. Patients who had a diagnosis of EDS were identified by International Classification of Diseases Coding. Propensity scores were utilized to match these patients with controls at a 1:4 ratio based on age, sex, and various comorbidities. Multivariable logistic regression analysis was used to compare the rates of medical and surgical complications at 90 days and 2 years. A total of 188 patients who had EDS and 752 controls were included in this study. RESULTS: After univariate analysis, Ehlers-Danlos patients exhibited significantly higher rates of wound complications (4.8 versus 0.9%, P = .001) at 90 days. When adjusted for comorbidities, Ehlers-Danlos patients still exhibited significantly increased odds of developing wound complications (odds ratio: 7.06; P < .001). CONCLUSIONS: Patients who have EDS undergoing TKA exhibited significantly higher rates of wound complications within 90 days postoperatively compared to matched controls. Rates of instability, manipulation under anesthesia, periprosthetic joint infection, aseptic loosening, and aseptic revision arthroplasty did not significantly differ between the cohorts. This study found generally favorable short-term outcomes of TKA in this population; however, the inability to control for implant type and other confounding variables may have influenced the lack of difference in complication rates at 2 years. Surgeons should monitor for the potentially increased risk of wound complications and consider the possible need for increased constraint in this population during preoperative planning.

Outcomes of Total Hip Arthroplasty in Patients Who Have Ehlers-Danlos Syndrome: A Matched Cohort Study.

INTRODUCTION: Total hip arthroplasty (THA) is an effective surgical treatment for severe osteoarthritis of the hip. While THA is considered a reliable and safe procedure, outcome data on patients who have Ehlers-Danlos syndrome (EDS) is limited. The purpose of this study was to compare rates of postoperative complications after primary THA in patients who have EDS against matched controls. METHODS: A large national database was searched to identify patients who underwent THA between 2009 and 2020. Patients younger than 18 years, who had a history of prior THA, and who were undergoing THA for a hip fracture were excluded from analysis. Propensity score matching was utilized to match patients who had EDS with patients who did not have EDS at a 1:4 ratio. Rates of medical and surgical complications at 90 days and 2 years were queried and compared between the cohorts using multivariable logistic regression. We identified 118 patients who had EDS and underwent primary THA, who were then matched with 418 controls. RESULTS: At 90 days, the EDS cohort had greater rates of dislocation (8.5 versus 3.8%, P = 0.038). At 2 years, the EDS cohort had greater odds of dislocation (OR [odds ratio] 2.47, P = 0.018), aseptic loosening (OR 6.91, P = 0.002), and aseptic revision (OR 2.66, P = 0.02). CONCLUSION: Patients who have EDS possess significantly higher odds of complications after THA compared to matched controls, including dislocation, aseptic loosening, and aseptic revision. Careful surgical planning in these patients should be made to prevent dislocation and potentially minimize the risk of other prosthesis-related complications leading to revision.

Early Versus Late Periprosthetic Joint Infection After Total Knee Arthroplasty: Do Patient Differences Exist?

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA). Little evidence exists comparing those with early versus late PJI. The purpose of the study was to determine comorbidity profile differences between patients developing early and late PJI. METHODS: There were 72,659 patients undergoing primary TKA from 2009 to 2021, who were identified from a commercial claims and encounters database. Subjects diagnosed with PJI were categorized as either 'early' (within 90 days of index procedure) or 'late' (> 2 years after index arthroplasty). Non-infected patients within these periods served as control groups following 4:1 propensity score matching on other extraneous variables. Logistic regression analyses were performed comparing comorbidities between groups. RESULTS: Patients were significantly younger in the late compared to the early infection group (58.1 versus 62.4 years, P < .001). When compared to those with early PJI, patients who had chronic kidney disease (13.3 versus 4.1%; OR [odds ratio] 5.17, P = .002), malignancy (20.4 versus 10.5%; OR 2.53, P = .009), uncomplicated diabetes (40.8 versus 30.6%; OR 2.00, P = .01), rheumatoid arthritis (9.2 versus 3.3%; OR 2.66, P = .046), and hypertension (88.8 versus 81.6%; OR 2.17, P = .04), were all significant predictors of developing a late PJI. CONCLUSIONS: When compared to patients diagnosed with early PJI following primary TKA, the presence of chronic kidney disease, malignancy, uncomplicated diabetes, rheumatoid arthritis, and hypertension, were independent risk factors for the development of late PJI. Younger patients who have these comorbidities may be targets for preoperative optimization interventions that minimize the risk of PJI.

Outcomes of Unicompartmental Knee Arthroplasty in Patients Receiving Long-Term Anticoagulation Therapy: A Propensity-Matched Cohort Study.

BACKGROUND: Although total knee arthroplasty has been considered the gold-standard treatment for severe osteoarthritis of the knee, unicompartmental knee arthroplasty (UKA) has become an increasingly favorable alternative for single-compartment osteoarthritis of the knee. Few studies have examined potential high-risk populations undergoing this procedure. The purpose of this study was to investigate the outcomes of UKA in patients receiving long-term anticoagulation therapy. METHODS: In this study, a large administrative database was queried to identify patients undergoing UKA between 2009 and 2019, who were then divided into a cohort receiving long-term anticoagulation and a control cohort. Propensity scores were utilized to match these patients. Multivariable logistic regression was utilized to compare 90-day and 2-year complication rates between cohorts. RESULTS: Patients who were on long-term anticoagulation had significantly increased odds of extended length of stay, surgical site infection, wound complication, transfusion, deep vein thrombosis, pulmonary embolism, and readmission at 90-day follow-up. The long-term anticoagulation cohort also experienced significantly higher odds of periprosthetic joint infection and mechanical complications at 2-year follow-up; however, odds of conversion to total knee arthroplasty were not increased. CONCLUSIONS: This study demonstrated that long-term anticoagulation use was associated with poorer medical and surgical outcomes at both 90 days and 2 years postoperatively in patients undergoing UKA, even after rigorous adjustment for confounders.

Age-Adjusted Modified Frailty Index Predicts 30-Day Complications and Mortality in Aseptic Revision Total Hip and Knee Arthroplasty.

BACKGROUND: The age-adjusted modified frailty index (aamFI) has been demonstrated to effectively predict postoperative complications and healthcare resource utilization in patients undergoing primary total joint arthroplasty. The purpose of this study was to evaluate the applicability of aamFI in patients undergoing aseptic revision total hip (rTHA) and knee arthroplasty (rTKA). METHODS: A national database was queried for patients undergoing aseptic rTHA and rTKA from 2015 to 2020. A total of 13,307 rTHA and 18,762 rTKA cases were identified. The aamFI was calculated by adding 1 additional point for age ≥73 years to the previously described 5-item modified frailty index (mFI-5). The area under the curve was calculated and compared to compare predictive accuracy between mFI-5 and aamFI. Logistic regression was used to investigate the relationship between aamFI and 30-day complications. RESULTS: The incidence of incurring any (≥1) complication increased from 15% for aamFI 0 to 45% for aamFI ≥5 after rTHA and from 5 to 55% after rTKA. Patients who had an aamFI ≥3 (reference aamFI = 0) had increased odds (rTHA: odds ratio (OR) 3.5, 95% confidence interval (CI) 2.9 to 4.1, P < .001; rTKA: OR 4.2, 95% CI 4.4 to 5.1, P < .001) of incurring at least 1 complication. The aamFI, compared to mFI-5, was a more accurate predictor of any complication (rTHA P < .001; rTKA P < .001) and 30-day mortality (rTHA P < .001; rTKA P < .003). CONCLUSION: The aamFI is an excellent predictor of complications in patients undergoing rTHA and rTKA. The addition of chronological age to the previously described mFI-5 improves the predictive value of this simple metric.

Chronic Anticoagulation is Associated With Increased Risk for Postoperative Complications Following Aseptic Revision Total Hip Arthroplasty.

BACKGROUND: With an aging global population, the incidence of revision total hip arthroplasty (rTHA) is expected to increase markedly. While patients undergoing primary total hip arthroplasty who require chronic anticoagulation (AC) have been associated with increased postoperative complications, less is known about the impact of chronic AC status on postoperative complications in the rTHA setting. This study sought to compare complication rates following aseptic rTHA between patients who were on chronic AC and those who were not. METHODS: A large national database was utilized to retrospectively identify 9,421 patients who underwent aseptic rTHA between 2014 and 2019. Patients were divided into 2 cohorts: 1,790 patients (19.0%) were in the chronic AC cohort (ie, having an AC prescription filled within 6 months prior to and following rTHA), and 7,631 patients (81.0%) were not on chronic AC. Postoperative complications at 90-days and 2-years were compared between cohorts utilizing univariate and multivariate analyses, controlling for sex, age, and comorbidities. RESULTS: At 90-days, chronic AC patients had increased odds of prosthetic joint infections (PJIs) (odds ratio [OR] 3.2, P < .001), surgical site infections (OR 3.6, P < .001), and mechanical prosthetic complications (OR 3.5, P < .001), which included any aseptic loosening, implant dislocation, or broken prosthetic. At 2-years, chronic AC patients had increased odds of PJI (OR 3.3, P < .001) as well as mechanical prosthetic complications (OR 3.2, P < .001). Chronic AC patients were also at increased risk for reoperation within 2 years after initial aseptic rTHA (OR 1.9, P < .001). CONCLUSIONS: Patients on chronic AC have significantly higher odds of 90-day and 2-year complications after aseptic rTHA. This includes increased odds of PJI, surgical site infection, and mechanical prosthetic complications. Patients receiving chronic AC who undergo rTHA should be counseled on the risk-benefit ratio of their chronic AC status in a multidisciplinary setting to optimize their postoperative outcomes.

Should All Patients Receive Extended Oral Antibiotic Prophylaxis? Defining Its Role in Patients Undergoing Primary and Aseptic Revision Total Joint Arthroplasty.

BACKGROUND: Prior studies have demonstrated reduced periprosthetic joint infection (PJI) rates following extended oral antibiotics (EOAs) for high-risk patients undergoing primary total joint arthroplasty (TJA). This study compared 3-month PJI rates in all patients undergoing primary or aseptic revision TJA with or without EOA prophylaxis. METHODS: In total, 2,982 consecutive primary (n = 2,677) and aseptic revision (n = 305) TJAs were performed by a single, fellowship-trained arthroplasty surgeon from 2016 to 2022 were retrospectively reviewed. Beginning January 2020, all patients received 7 days of 300 mg oral cefdinir twice daily immediately postoperatively. Rates of PJI at 3 months were compared between patients who received or did not receive EOA. RESULTS: Rates of PJI at 3 months in patients undergoing primary and aseptic revision TJA were significantly lower in those receiving EOA prophylaxis compared to those who did not (0.41 versus 1.13%, respectively; P = .02). After primary TJA, lower PJI rates were observed with EOA prophylaxis utilization (0.23 versus 0.74%, P = .04; odds ratio [OR] 3.85). Following aseptic revision TJA, PJI rates trended toward a significant decrease with the EOA compared to without (1.88 versus 4.83%, respectively; P = .16; OR 2.71). CONCLUSIONS: All patients undergoing primary or aseptic revision TJA who received EOA prophylaxis were 3.85 and 2.71 times less likely, respectively, to develop PJI at 3 months compared to those without EOA. Future studies are needed to determine if these results are maintained at postoperative time periods beyond 3 months following primary TJA. LEVEL OF EVIDENCE: III, Retrospective review.

Complications and opioid-prescribing patterns following genicular nerve radiofrequency ablation versus intra-articular injection: a matched cohort study.

BACKGROUND AND OBJECTIVES: Genicular nerve radiofrequency ablation (GNRFA) is an emerging procedure used to relieve pain from severe knee osteoarthritis. While there have been rare reports of significant complications, their incidence has not been well established. The objective of this study was to examine complication rates at 30 and 90 days post treatment as well as characterize opioid-prescribing patterns before and after treatment. METHODS: A large national database was queried to identify patients undergoing GNRFA from 2015 to 2022 and matched to control cohorts composed of patients receiving either intra-articular corticosteroid (CSI) or hyaluronic acid injection (HAI) of the knee. Complication rates at 30 and 90 days were analyzed. Opioid utilization was assessed in the 6 months before and after treatment. RESULTS: Rates of infection (0.1%, CI 0.02% to 0.5% vs 0.2%, CI 0.05% to 0.6%), septic arthritis (<0.1%, CI 0.003% to 0.4% vs 0.1%, CI 0.02% to 0.5%), deep vein thrombosis (2.0%, CI 1.3% to 2.7% vs 1.6%, CI 1.0% to 2.2%), pulmonary embolism (1.2%, CI 0.6% to 1.7% vs 1.3%, CI 1.1% to 2.5%), bleeding (<0.1%, CI 0.003% to 0.4% vs 0%, CI 0% to 0.3%), seroma (<0.1%, CI 0.003% to 0.4% vs 0.2%, CI 0.05% to 0.6%), nerve injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%) and thermal injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%) were not different between CSI and GNRFA cohorts at 30 days. Rate of swelling was significantly greater in the GNRFA cohort (9.4%, CI 7.6% to 10.4% vs 6.4%, CI 4.8% to 7.2%, p=0.003) at 30 days. At 90 days, rates of septic arthritis (0.1%, CI 0.02% to 0.5% vs 0.3%, CI 0.08% to 0.7%), deep vein thrombosis (3.1%, CI 2.1% to 3.8% vs 3.1%, CI 2.2% to 3.9%), pulmonary embolism (1.5%, CI 0.9% to 2.1% vs 1.8%, CI 1.2% to 2.5%), and nerve injury (0%, CI 0% to 0.3% vs <0.1%, CI 0.003% to 0.4%) were not significantly different.Between HAI versus GNRFA cohorts, no significant differences were seen in rates of infection (0.3%, CI 0.08% to 0.07% vs 0.7%, CI 0.3% to 1.2%), septic arthritis (0.2%, CI 0.05% to 0.6% vs 0.4%, CI 0.2% to 0.9%), deep vein thrombosis (2.0%, CI 1.3% to 2.7% vs 1.9%, CI 1.2% to 2.7%), pulmonary embolism (1.5%, CI 0.9% to 2.2% vs 1.7%, CI 1.1% to 2.5%), bleeding (0.1%, CI 0.02% to 0.5% vs 0.2%, CI 0.05% to 0.6%), seroma (<0.1%, CI 0.03% to 0.4% vs 0%, CI 0% to 0.3%), nerve injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%), swelling (14.0%, CI 11.6% to 15.1% vs 12.0%, CI 10.3% to 13.6%), and thermal injury (<0.1%, CI 0.03% to 0.4% vs <0.01%, CI 0.3% to 0.4%) at 30 days. Rates of infection (0.7%, CI 0.3% to 1.2% vs 1.4%, CI 0.9% to 2.1%), septic arthritis (0.3%, CI 0.1% to 0.8% vs 0.5%, CI 0.2% to 1.1%), deep vein thrombosis (3.6%, CI 2.6% to 4.4% vs 3.1%, CI 2.2% to 4.0%), pulmonary embolism (2.3%, CI 1.5% to 3.0% vs 2.1%, CI 1.4% to 3.0%) and nerve injury (0%, CI 0% to 0.3% vs 0.1%, CI 0.02% to 0.5%) were not significantly different at 90 days.There were no significant differences in level of pretreatment opioid utilization although overall consumption in mean daily morphine equivalents was greater in the GNRFA cohort. Opioid utilization significantly increased in the first 30 days after ablation in patients with no prior opioid use compared to controls. In patients with some and chronic prior opioid use, opioid requirements were generally decreased in all treatment groups at 6 months with no clearly superior treatment in reducing opioid consumption. CONCLUSION: Our study demonstrated that GNRFA possesses a safety profile similar to that of intra-articular injections although significant adverse events such as venous thromboembolism and septic arthritis may occur rarely. Although opioid utilization generally increased in the 30 days after ablation compared with intra-articular injection, similar reduction in opioid consumption at 6 months was seen in patients with prior opioid use in the ablation and control cohorts.

Orthopaedic and trauma research in Tanzania: A scoping review.

Tanzania is disproportionately burdened by musculoskeletal injuries as it faces unique challenges when dealing with trauma care. This scoping review aims to summarize and assess the current state of orthopaedic and trauma research in Tanzania. By identifying key themes, trends, and gaps in the literature, this review seeks to guide future research initiatives catered specifically to the needs of Tanzania's healthcare system. Utilizing the PRISMA-ScR protocol, OVID Medline, PubMed, and CINAHL databases were searched from inception to June 17, 2023, using keywords such as "Orthopaedics" "Trauma" and "Tanzania". One hundred and ninety-two eligible studies were included and the Arksey and O'Malley framework for scoping studies was followed. There was a notable growth of relevant publications from 2015 onward, with peaks in growth in the years 2019, 2021, and 2020. The studies employed diverse research methodologies, with cross-sectional (n = 41, 21%) and prospective studies (n = 39, 20%) being the most prevalent, and randomized-controlled trials being the least prevalent methodology, making up eight studies (4.2%). The most common study themes were trauma (n = 101, 52.6%), lower extremity (n = 31, 16%), and spine-related issues (n = 27, 14%). Only three studies looked at work-related injuries (1.6%). Road traffic injuries (RTIs) were the most common mechanism of trauma in 77.0% of the trauma focused studies. Fifty-three percent of the studies were conducted by a majority of Tanzanian authors. This scoping review highlights various trends in orthopaedic and trauma research in Tanzania, with a particular emphasis on road traffic-related injuries. Various gaps are explored, including a lack of research on work-related injuries and a paucity of experimental research. Our findings underline areas where future research is warranted. The future of orthopaedic and trauma care in Tanzania depends on the efforts and collaboration of both local and international stakeholders.

Total Hip Arthroplasty With Subtrochanteric Osteotomy for Crowe IV Dysplasia Using an Extensile Direct Anterior Approach: A Surgical Technique.

The direct anterior approach (DAA) has been increasing in popularity for primary total hip arthroplasty (THA). Despite previously documented anatomic limitations to its direct distal extension, alternative exposure methods have been described to safely access the femoral diaphysis and facilitate increasingly complex primary and revision THA scenarios. The DAA has several purported advantages compared to alternative approaches (eg, posterior and lateral-based), including its muscle-sparing nature, use of an internervous plane, and preservation of posterior stabilizing structures. Proponents of the DAA cite decreased postoperative pain, quicker recovery times, potentially lower dislocation rates, ease of intraoperative fluoroscopy, and improved implant placement/restoration of leg lengths. The current literature, however, is sparse when considering the use of this approach in the setting of severely dysplastic hips necessitating a concurrent subtrochanteric shortening osteotomy. When utilizing a posterior approach in this population, previous work from Ollivier and colleagues demonstrated high rates of cementless implant osseointegration and significantly improved clinical outcomes at long-term follow-up. Although relatively few reports of addressing this pathology via the DAA currently exist, initial results are promising. This study seeks to provide a detailed description of a surgical technique for performing primary THA and ipsilateral subtrochanteric shortening osteotomy in this patient population utilizing an extensile DAA.

Defining the Learning Period of a Novel Imageless Navigation System for Posterior Approach Total Hip Arthroplasty: Analysis of Surgical Time and Accuracy.

Introduction: The use of imageless navigation in total hip arthroplasty (THA) is frequently associated with prolonged surgical times, predominantly during the learning period. The purpose of the present study was to characterize the learning period of a novel imageless navigation system, specifically as it related to surgical time and acetabular navigation accuracy. Materials and Methods: This was a retrospective observational study of a consecutive group of 158 patients who underwent primary unilateral THA for osteoarthritis by a team headed by a single surgeon. All procedures used an imageless navigation system to measure acetabular cup inclination and anteversion angles, referencing a generic sagittal and frontal plane. Navigation accuracy was determined by assessing differences between intraoperative inclination and anteversion values and those obtained from standardized 6-week follow-up radiographs. Operative time and navigation accuracy were assessed by plotting moving averages of 7 consecutive cases. The learning period was defined using Mann-Kendall trend analyses, student t-tests and nonlinear regression modeling based on surgical time and navigation accuracy. Alpha error was 0.05. Results: The average surgical time was 67.3 min (SD:9.2) (range 45-95). The average navigation accuracy for inclination was 0.01° (SD:4.2) (range - 10 to 10), and that for anteversion was - 4.9° (SD:3.8) (range - 14 to 5). Average surgical time and navigation accuracy were similar between the first and final cases in the series with no learning period detected. Conclusions: There was no discernible learning period effect on surgical time or system measurement accuracy during the early phases of adoption for this imageless navigation system.

AI-Generated Graduate Medical Education Content for Total Joint Arthroplasty: Comparing ChatGPT Against Orthopaedic Fellows.

Background: Artificial intelligence (AI) in medicine has primarily focused on diagnosing and treating diseases and assisting in the development of academic scholarly work. This study aimed to evaluate a new use of AI in orthopaedics: content generation for professional medical education. Quality, accuracy, and time were compared between content created by ChatGPT and orthopaedic surgery clinical fellows. Methods: ChatGPT and 3 orthopaedic adult reconstruction fellows were tasked with creating educational summaries of 5 total joint arthroplasty-related topics. Responses were evaluated across 5 domains by 4 blinded reviewers from different institutions who are all current or former total joint arthroplasty fellowship directors or national arthroplasty board review course directors. Results: ChatGPT created better orthopaedic content than fellows when mean aggregate scores for all 5 topics and domains were compared (P ≤ .001). The only domain in which fellows outperformed ChatGPT was the integration of key points and references (P = .006). ChatGPT outperformed the fellows in response time, averaging 16.6 seconds vs the fellows' 94 minutes per prompt (P = .002). Conclusions: With its efficient and accurate content generation, the current findings underscore ChatGPT's potential as an adjunctive tool to enhance orthopaedic arthroplasty graduate medical education. Future studies are warranted to explore AI's role further and optimize its utility in augmenting the educational development of arthroplasty trainees.

Robotic-Arm-Assisted Lateral Unicompartmental Knee Arthroplasty with a Fixed-Bearing Implant.

Background: Approximately 5% to 10% of patients with knee arthritis have isolated lateral compartment arthritis; however, lateral unicompartmental knee arthroplasty (UKA) comprises just 1% of all knee arthroplasties1. This low proportion is partly because of the perceived complexity of lateral UKA and concerns over implant longevity and survivorship compared with total knee arthroplasty (TKA)2,3. With an improved understanding of knee kinematics alongside advances in implant design and tools to aid in appropriate restoration of limb alignment, lateral UKA can be an appealing surgical alternative to TKA for certain patients with lateral knee arthritis4,5. In appropriately selected patients, lateral UKA has been associated with reduced osseous and soft-tissue resection, more natural knee kinematics, less pain, shorter hospitalization, decreased blood loss and infection rates, and excellent survivorship and patient-reported outcomes6-9. Description: This surgical approach and technique described for lateral UKA utilizes robotic-arm assistance and modern fixed-bearing implants10. The specific steps involve appropriate patient evaluation and selection, extensive radiographic and computed-tomography-based preoperative templating, a lateral parapatellar approach, intraoperative confirmation of component position and alignment, and robotic-arm assistance to perform osseous resections to achieve limb alignment and kinematic targets10. Final implants are cemented in place, and patients typically are discharged home on the day of surgery10. Alternatives: Nonoperative treatment for end-stage knee arthritis includes weight loss, activity modification, assistive devices, bracing, nonsteroidal anti-inflammatory medications, and various injections11. Alternative surgical treatments include TKA4 and, in certain patients, an offloading periarticular osteotomy12. Rationale: Lateral UKA is an appealing surgical option for nonobese patients who have disabling knee pain isolated to the lateral compartment, good preoperative range of motion, and a passively correctable valgus limb deformity10,13. Expected Outcomes: Patients are typically discharged home on the day of surgery, or occasionally on postoperative day 1 if medical comorbidities dictate hospital monitoring overnight10. Patients return to light activities, including walking, immediately postoperatively. By 3 months postoperatively, patients will generally have returned to all desired activities9. The mid-term outcomes of this procedure, as performed by the corresponding author, have been published recently14,15. The 5-year survivorship of 171 lateral UKAs was 97.7%, with 72.8% of patients reporting that they were very satisfied with their procedure and 19.8%, that they were satisfied14. Only 3.8% of patients reported dissatisfaction with their lateral UKA14. The mean Knee Injury and Osteoarthritis Outcome Score (KOOS) and standard deviation were 85.6 ± 14.314. These outcomes did not differ from those observed in 802 medial UKAs, which showed a survivorship of 97.8% and KOOS of 84.3 ± 15.914. These findings are generally in line with previously published studies, which have demonstrated excellent survivorship and patient-reported outcomes with fixed-bearing lateral UKA16-19. Important Tips: Component position and alignment are critical to achieve target knee kinematics.Target postoperative alignment is 1° to 4° of valgus.A meticulous cementation technique is required for optimal fixation and avoidance of excess residual cement in the posterior knee. Acronyms and Abbreviations: ACL = anterior cruciate ligamentAP = anteroposteriorBMI = body mass indexCT = computed tomographyCAT = computed axial tomographyIT = iliotibialKOOS JR = Knee Injury and Osteoarthritis Outcome Score for Joint ReplacementMCL = medial collateral ligamentMRI = magnetic resonance imagingOR = operating roomPFJ = patellofemoral jointpoly = polyethyleneROM = range of motionTKA = total knee arthroplastyUKA = unicompartmental knee arthroplasty.