Robotic Total Knee Arthroplasty vs Conventional Total Knee Arthroplasty: A Nationwide Database Study

Autonomous Robotic Systems in Otolaryngology-Head and Neck Surgery

Robotic surgery is a growing field with increasing applications to patient care. With the rising use of artificial intelligence (AI), a new frontier emerges, allowing semiautonomous robotics. This article reviews the origins of robotic surgery and subsequent trials of automaticity in all fields. It then describes specific nascent robotic and semiautonomous surgical prototypes within the field of otolaryngology. Finally, broader systemic considerations are posited regarding the implementation of AI-driven robotics in surgery.

Enhanced recovery after surgery day surgery for MAKO® robotic-arm assisted TKA; better outcome for patients, improved efficiency for hospitals

Introduction

Robotic-assisted Total Knee Arthroplasty (TKA) was designed to improve implant position accuracy by providing surgeons with real-time intra-operative data to tailor the operation to the patient. Proponents of robotic-assisted TKA believe that this translates into meaningful improvements in outcomes. However, there are concerns that the longer surgical duration associated with robotic-assisted TKA leads to longer length of stay (LOS). In this study, the authors investigated the outcome of MAKO® Robotic-arm Assisted TKA combined with ERAS protocol to assess its effect on LOS and short-term outcomes.

Methods

All patients who had undergone unilateral MAKO® ERAS Day Surgery TKA from August 2020 to July 2021 were prospectively followed up and matched to patients who underwent conventional ERAS Day Surgery TKA in the same time period. Factors such as surgical duration, LOS, immediate reduction in pain, 30-days complications, and 6-month PROMs and knee ROM were compared between the two groups.

Results

42 patients underwent MAKO® ERAS Day surgery TKA and were matched to 42 patients who underwent conventional ERAS Day surgery TKA. The study found that despite the longer surgical duration, LOS was comparable between both groups (1.1 ± 0.9days in the MAKO® group vs 1.0 ± 0.3days in the conventional group, p = 0.755) with successful 24-hour discharge in 88.1 % of patients in the MAKO® group. The MAKO® group achieved significantly better ROM compared to the conventional group 6-months post operatively. Post-operative PROMs were comparable between both groups.

Conclusion

ERAS Day Surgery protocol can significantly reduce the LOS of patient undergoing MAKO® Robotic-arm Assisted TKA, conferring cost savings and making it a valid option for patients.

Robotic arm-assisted versus conventional total knee arthroplasty: comparing complications, costs, and postoperative opioid use in propensity-matched cohorts

PURPOSE

Limited literature exists substantiating benefits of robotic arm-assisted total knee arthroplasty (raTKA) over conventional total knee arthroplasty (cTKA). This study compared postoperative pain, complications, and costs between patients undergoing raTKA and cTKA using large, propensity score-matched cohorts. We hypothesize that the raTKA cohort will be associated with lower pain, lower anemia, and similar cost and other complications.

METHODS

A commercially available patient database was used for this study. Patients with raTKA and cTKA were identified with current procedural terminology and international classification of diseases (ICD-9/ICD-10) codes. Exclusions and propensity score matching were applied to mitigate confounding bias. Complication rates, costs, and postoperative opioid uses were then compared between groups.

RESULTS

Compared with patients with cTKAs (n = 31,105), patients with raTKAs (n = 6,221) had less postoperative opioid use (p < 0.01), lower rates of postoperative acute renal failure (OR 0.71; p < 0.01), anemia (OR 0.75; p < 0.01), and periprosthetic joint infection (OR 0.59; p = 0.04), and lower index costs ($875 vs. $1,169, p < 0.01).

CONCLUSION

RaTKA was associated with less postoperative pain and complications compared with cTKA.

Correlation Between Planned and Executed Bone Cuts Using Robotics in Total Knee Arthroplasty: A Prospective Study of 500 Patients

Objective

This study evaluated the precision of robotic-arm-assisted total knee arthroplasty (RATKA) in performing bone resection, predicting component size, managing soft tissue tension, and determining postoperative range of motion (ROM).

Methods

A total of 500 participants were enrolled in this prospective cohort research. The procedures were conducted at a single facility, with a uniform method and implant design. The Cuvis system, a fully automated robot, was utilized for the study. The precise removal of bone at both the tibial and femur sites, the positioning of the implant, and the release of soft tissue were documented and then compared to the preoperative plan.

Results

The distal (medial and lateral) femoral cuts had a mean absolute deviation from the plan of 0.23 mm, while the posterior (medial and lateral) femoral cuts had a mean absolute difference of 1 mm and 1.4 mm, respectively. The absolute discrepancies in the medial and lateral tibial cuts are 0.93 mm and - 0.06 mm, respectively. Out of 1000 bone resections, 980 (98%) were within < 1 mm from the preoperative plan. The predictions for the sizes of the tibial and femoral components had accuracies of 100% and 98.9%, respectively.

Conclusion

These findings collectively underscore the effectiveness of the fully automated Cuvis robotic system in achieving consistent and accurate results in bone resections and implant sizing, highlighting its potential as a valuable tool in orthopedic surgery.

The environmental impact of hip and knee arthroplasty: An analysis of carbon emissions and disposal costs

BACKGROUND AND PURPOSE

The rise in hip and knee arthroplasty for osteoarthritis requires addressing healthcare system pollution to support Ireland's climate change goals. This research aimed to quantify waste generated and determine environmental and economic impacts to promote sustainable strategies in joint arthroplasty and shed light on the suboptimal waste management practices.

METHODS

The study was conducted at National Orthopaedic Hospital Cappagh (NOHC), measuring waste generated during hip and knee arthroplasty. Clinical, domestic, and recycled waste weights were recorded, including the segregation of Central Sterile Supply Department (CSSD) Blue Wrap waste in ten operations. Kilograms of carbon dioxide emissions (kgCO2e) and disposal costs were calculated.

RESULTS

In a sample of 100 joint arthroplasty operations, the study found that revision knees produced 23.58 ​kgCO2e per case, revision hips 23.50 ​kgCO2e, primary knees 15.82 ​kgCO2e, and primary hips 14.64 ​kgCO2e. CSSD Blue Wrap contributed on average 13.5% of OT waste. Extrapolating these findings to the estimated number of joint arthroplasties performed in 2022 ​at NOHC (1556 hip and knee joint arthroplasties), the emissions were estimated to be 24,576 kgCO2e, with the cost of disposal up to €29,228. Strategies to mitigate this waste have been identified and proposed.

CONCLUSION

The research aimed to address the environmental impact of orthopaedic joint arthroplasties, offering strategies to reduce waste generation, carbon emissions, and cost. Utilising our methodology to calculate greenhouse gas emissions will empower sustainability offices to conduct their own waste audits and implementing our strategies for waste management practices can help minimise environmental waste.

Opioid Use After Robotic-Assisted Versus Conventional Total Hip Arthroplasty:A National Database Analysis

BACKGROUND

In this study, we tested the null hypothesis that robotic-assisted total hip arthroplasty (THA) vs conventional THA was not associated with (1) the amount of postoperative opioid use and (2) the incidence of new, persistent opioid use.

MATERIALS AND METHODS

We used a large, national administrative database to identify patients 50 years and older undergoing primary robotic or conventional THA. Patients with hip fractures or a history of malignancy, hip infection, or opioid use disorder were excluded. Patients who filled an opioid prescription within 1 year to 30 days preoperatively or who underwent a subsequent procedure within 1 year after THA were excluded. Outcomes included the morphine milligram equivalents (MMEs) filled within the THA perioperative period and the incidence of new, persistent opioid use. Multivariable logistic regression models were used to evaluate associations between robotic-assisted THA and new, persistent opioid use, adjusting for age, sex, insurance plan, region, location of surgery, and comorbidities.

RESULTS

In the postoperative period, robotic-assisted THA, compared with conventional THA, was associated with a lower mean total MMEs filled per patient (452.2 vs 517.1; P<.001) and a lower mean MMEs per patient per day (71.53 vs 74.64; P<.001). Patients undergoing robotic-assisted THA had decreased odds of developing new, persistent opioid use compared with patients undergoing conventional THA (adjusted odds ratio, 0.82 [95% CI, 0.74-0.90]).

CONCLUSION

Robotic-assisted THA is associated with lower postoperative opioid use and a decreased odds of developing new, persistent opioid use compared with conventional THA. For the purposes of reducing opioid use, our results support the adoption of robotic-assisted THA. [Orthopedics. 202x;4x(x):xx-xx.].

Robotic-assisted total knee arthroplasty reduces postoperative complications and length of stay without increased cost compared to navigation-guided techniques: A national analysis

INTRODUCTION

This study compares postoperative outcomes of robotic-assisted total knee arthroplasty (RA-TKA) versus navigation-guided total knee arthroplasty (NG-TKA). Using Nationwide Inpatient Sample (NIS) data, it provides an analysis of postoperative complications, mortality, hospital costs and duration of stay.

METHODS

The study analysed 217,715 patients (81,830 RA-TKA; 135,885 NG-TKA) using NIS data from 2016 to 2019. Elective TKA patients were identified through the International Classification of Diseases, 10th Revision codes. Statistical analyses, including logistic regression modelling, were performed using Statistical Package for the Social Sciences and MATLAB.

RESULTS

RA-TKA patients were younger (66.1 vs. 67.1 years, p < 0.0001) and had similar mortality rates (0.024% vs. 0.018%, p = 0.342) but shorter length of stay (LOS) (1.89 vs. 2.1 days, p < 0.0001). Mean total charges were comparable between RA-TKA ($66,180) and NG-TKA ($66,251, p = 0.669). RA-TKA demonstrated lower incidences of blood-related complications (11.67% vs. 14.19%, p < 0.0001), pulmonary oedema (0.0306% vs. 0.066%, p < 0.0001), deep vein thrombosis (0.196% vs. 0.254%, p = 0.006) and acute kidney injury (AKI) (1.356% vs. 1.483%, p = 0.016).

CONCLUSION

RA-TKA reduces postoperative complications and LOS without increasing costs, highlighting the relevance of this technology in patient care.

LEVEL OF EVIDENCE

Level III.

A Perspective of Growth of Unicompartmental Knee Replacement in India - Registry Data and Global Trends

Introduction

The purpose of this study is to analyze the trend of unicompartmental knee replacement (UKR) in India, based on the data obtained from the Indian joint registry, in comparison with the global trends.

Materials and Methods

This study is a retrospective analysis of data from an Indian joint registry for cases performed between 2016 and 2021. A total of 1086 UKRs were identified and the following information was analyzed: demographic data, diagnosis leading to primary UKR, yearwise surgeon inclination toward UKR, implant preference, regions where UKR was preferred, and the effect of robotics in UKR. UKR registry data were compared with the registry data from the UK (NJR), Sweden (SKAR), Australia (AOJR), and the USA (AJRR).

Results

One thousand eighty-six UKRs were included in the study: The vast majority of them (97%) were implanted due to primary osteoarthritis followed by deformity (2%), as in accordance with other registries. Since 2016, though very minimal, there has been a gradual increase in the numbers and the percentage of cases contributed by UKR, of all knee replacements with the maximum of 2.85% reported in 2019. The same has been observed in the global trends as well. Oxford knees (60%) are the most preferred implants followed by journey uni knee (20%) in India. The cities where more unicompartmental knee are performed are in the order of Mumbai (32.78%), Faridabad (9.39%), Pune (7.92%), and Hyderabad (6.35%). Surgeon preference for robotic assisted UKR is increasing, accounting for 34% of UKR in 2020, which is in coherence with AOJR.

Conclusion

The percentage of knee replacements contributed by UKR is increasing globally and the same trend can be observed in India. Oxford phase III prosthesis are the most preferred UKR prosthesis. UKRs are mostly performed in selected pockets of India, with Mumbai almost contributing to one-third of all the cases. The use of robotics in UKR is increasing and is expected to give better results in the future.

Lower Perioperative Complication Rates and Shorter Lengths of Hospital Stay Associated With Technology-Assisted Total Knee Arthroplasty Versus Conventional Instrumentation in Primary Total Knee Arthroplasty

BACKGROUND

The use of technology allows increased precision in component positioning in total knee arthroplasty (TKA). The objectives of this study were to compare (1) perioperative complications and (2) resource utilization between robotic-assisted (RA) and computer-navigated (CN) versus conventional (CI) TKA.

METHODS

A retrospective cohort study was performed using a national database to identify patients undergoing unilateral, primary elective TKA from January 2016 to December 2019. A total of 2,174,685 patients were identified and included RA (69,445), CN (112,225), or CI (1,993,015) TKA. Demographics, complications, lengths of stay, dispositions, and costs were compared between the cohorts. Binary logistic regression analysis was performed.

RESULTS

The RA TKA cohort had lower rates of intraoperative fracture (0.05 versus 0.08%, P < .05), respiratory complications (0.6 versus 1.1%, P < .05), renal failure (1.3 versus 1.7%, P < .05), delirium (0.1 versus 0.2%, P < .05), gastrointestinal complications (0.04 versus 0.09%, P < .05), postoperative anemia (8.9 versus 13.9%, P < .05), blood transfusion (0.4 versus 0.9%, P < .05), pulmonary embolism, and deep vein thrombosis (0.1 versus 0.2%, P < .05), and mortality (0.01 versus 0.02%, P < .05) compared to conventional TKA, though the cohort did have higher rates of myocardial infarction (0.09 versus 0.07%, P < .05). The CN cohort had lower rates of myocardial infarction (0.02 versus 0.07%, P < .05), respiratory complications (0.8 versus 1.1%, P < .05), renal failure (1.5 versus 1.7%, P < .05), blood transfusion (0.8 versus 0.9%, P < .05), pulmonary embolism (0.08 versus 0.2%, P < .05), and deep vein thrombosis (0.2 versus 0.2%, P < .05) over CI TKA. Total cost was increased in RA (16,190 versus $15,133, P < .05) and CN (17,448 versus $15,133, P < .05). However, the length of hospital stay was decreased in both RA (1.8 versus 2.2 days, P < .05) and CN (2.1 versus 2.2 days, P < .05).

CONCLUSIONS

Technology-assisted TKA was associated with lower perioperative complication rates and faster recovery.

Robotic Total Knee Arthroplasty Surgeon Marketing: Do Claims Align With the Literature?

Background

Robotic total knee arthroplasty (R-TKA) utilization and marketing continue to rise. We examined the marketing on surgeon websites regarding R-TKA benefits and sought to determine if the claims were supported by existing literature.

Methods

A Google search identified 10 physician websites from each of the 5 largest U.S. markets by population with the term "robotic total knee arthroplasty city, state." Claims on websites about R-TKA were categorized. Literature from 2012-2022 was reviewed for data "for" or "against" each claim. Level of evidence for each publication was collected.

Results

Fifty websites were captured that included 59 surgeons. A specific R-TKA platform was mentioned on 68% of websites. Website claims about robotics were placed into 8 major categories. Literature review supported the claims of more precise/accurate, reduced injury to tissue, and less pain with more literature "for" than "against" the claims.

Conclusions

Claims made on physician websites regarding the benefits of R-TKA are variable and not definitively supported by existing literature. Most available data can be categorized into levels of evidence III, IV, and V. There is a paucity of level I evidence to support the various marketing statements. Physicians should be cognizant of both the claims made on their websites and the literature that could be used to support or refute those specific claims.

Robotic Total Knee Arthroplasty: An Update

Total knee arthroplasty (TKA) is a gold standard surgical procedure to improve pain and restore function in patients affected by moderate-to-severe severe gonarthrosis refractory to conservative treatments. Indeed, millions of these procedures are conducted yearly worldwide, with their number expected to increase in an ageing and more demanding population. Despite the progress that has been made in optimizing surgical techniques, prosthetic designs, and durability, up to 20% of patients are dissatisfied by the procedure or still report knee pain. From this perspective, the introduction of robotic TKA (R-TKA) in the late 1990s represented a valuable instrument in performing more accurate bone cuts and improving clinical outcomes. On the other hand, prolonged operative time, increased complications, and high costs of the devices slow down the diffusion of R-TKA. The advent of newer technological devices, including those using navigation systems, has made robotic surgery in the operatory room more common since the last decade. At present, many different robots are available, representing promising solutions to avoid persistent knee pain after TKA. We hereby describe their functionality, analyze potential benefits, and hint at future perspectives in this promising field.

Outcomes following robotic assisted total knee arthroplasty compared to conventional total knee arthroplasty

INTRODUCTION

This study elaborates on previous research to compare length of stay, complication rates, and total cost between patients undergoing robotic assisted total knee arthroplasty (rTKA) and conventional total knee arthroplasty (cTKA). We hypothesized that patients undergoing rTKA would have reduced length of stay, lower complication rates, improved perioperative outcomes, and higher total healthcare costs than those undergoing cTKA.

METHODS

Data were collected from the National Inpatient Sample Database Healthcare Cost and Utilization Project between the years 2016-2019. Patients undergoing rTKA and cTKA were identified under International Classification of Diseases, 10th revision codes (ICD-10-CM/PCS). Length of stay, specific complications, and total costs were examined at time point. SPSS (v 27.0 8, IBM Corp. Armonk, NY) was utilized to compare demographic and analytical statistics between rTKA and cTKA. rTKA and cTKA were compared both before and after propensity matching.

RESULTS

17,249 rTKA (3.09%) and 541,122 cTKA (96.91%) were included. Compared to cTKA patients, rTKA patients had reduced average length of stay of 1.91 days (p < 0.001), higher average total cost of $67133.34 (p < 0.001), reduced periprosthetic infection (OR = 0.027, p < 0.001), periprosthetic dislocation (OR = 0.117, p < 0.001), periprosthetic mechanical complication (OR = 0.315, p < 0.001), pulmonary embolism (OR = 0.358, p < 0.001), transfusion (OR = 0.366, p < 0.001), pneumonia (OR = 0.468, p = 0.002), deep vein thrombosis (OR = 0.479, p = 0.001), and blood loss anemia (OR = 0.728, p < 0.001). These differences remained statistically significant even after propensity matching.

CONCLUSIONS

This study supports our hypothesis that rTKA is associated with fewer complications, but higher average total cost than cTKA. Our study shows that rTKA can be safely performed in older and sicker patients. Future studies assessing the impacts of these findings on patient reported outcomes would provide further insight into the benefits of rTKA. Furthermore, identifying patient specific factors that place them at risk for increased complications with cTKA as opposed to rTKA could provide surgeons insight on the method of TKA that maximizes patient outcomes while minimizing healthcare cost.

Comparison of imageless robotic assisted total knee arthroplasty and conventional total knee arthroplasty: early clinical and radiological outcomes of 200 knees

The aim of this study was to compare the short term clinical and radiological outcomes of imageless robotic and conventional total knee arthroplasty (TKA) and to estimate the accuracy of the two techniques by analysing the outliers after TKA. We have evaluated 200 consecutive knees (158 patients), 100 knees undergoing robotic TKA, and 100 knees treated with conventional TKA. Demographic parameters like age, gender, body mass index, diagnosis and range of motion were obtained. Knee society score (KSS) and Knee society functional score (KSS-F) were used for clinical evaluation. Mechanical alignment (Hip-knee-ankle angle), proximal tibial angle (MPTA), distal femoral angle (LDFA) and tibial slope were analysed for radiological results and outliers were compared between both groups. Outliers were defined when the measured angle exceeded ± 3° from the neutral alignment in each radiological measurement on the final follow-up radiograph.The minimum follow-up was 6 months (range, 6 to 18 months). The preoperative mean HKA angle was 169.7 ± 11.3° in robotic group and 169.3 ± 7.3° in conventional group. There was significant improvement in HKA, LDFA, MPTA and tibial slope compared to the preoperative values in both the groups (p < 0.01). The number of HKA, LDFA and tibial slope outliers were 31, 29 and 37, respectively, in the conventional group compared to 13, 23 and 17 in the robotic group (p < 0.01). There was a significant improvement in the KSS and KSS-F functional scores postoperatively in both the groups (p < 0.01). However, there was no significant difference in the functional scores between the groups postoperatively (p = 0.08). This study showed excellent improvement with both imageless robotic and conventional TKA, with similar clinical outcomes between both groups. However, radiologically robotic TKA showed better accuracy and consistency with fewer outliers compared with conventional TKA.

Robotic-assisted Total Knee Arthroplasty Reduces Radiographic Outliers for Low-volume Total Knee Arthroplasty Surgeons

Background

Most studies evaluating robotic-assisted total knee arthroplasty (RA TKA) analyzed the advantages offered to high-volume surgeons. This study aims to determine if RA TKA improves radiographic or clinical outcomes for low-volume, non-arthroplasty-trained surgeons.

Methods

Radiographic and early clinical outcomes of 19 RA TKAs and 41 conventional TKAs, all performed by a single, non-arthroplasty-trained orthopaedic surgeon, were compared. Radiographic outliers were based on surgeon targets and defined as tibial posterior slope outside of 0°-5°, tibial tray varus outside of 0°-3°, and the presence of notching. Clinical outcomes included inpatient narcotic usage, length of stay, range of motion, and Patient-Reported Outcome Measurement Information System scores.

Results

There was a significant decrease in tibial slope outliers (RA TKA 0% vs non-RA TKA 22%, P = .024) and notching incidence (RA TKA 0% vs non-RA TKA 19.5%, P = .044) in the RA group. Tibial tray varus/valgus outliers trended lower in the RA TKA group (10.0% vs 26.8%, P = .189). Length of stay was significantly shorter in RA patients (48.0 hours [standard deviation: 25.5] vs 67.7 hours [34.3], P = .038). RA patients trended toward lower in postoperative inpatient total mean morphine equivalents usage (79.9 [89.2] vs 140.1 [169.3], P = .142) and inpatient mean morphine equivalents usage per day (30.36 [26.9] vs 45.6 [36.7], P = .105). There was no significant difference in Patient-Reported Outcome Measurement Information System scores or range of motion at first and second postoperative follow-up within 3 months.

Conclusions

RA TKA reduced the incidence of radiographic outliers when compared to conventional TKA for a low-volume arthroplasty surgeon.

Does Computer Navigation or Robotic Assistance Affect the Risk of Periprosthetic Joint Infection in Primary Total Knee Arthroplasty? A Propensity Score-Matched Cohort Analysis

BACKGROUND

The use of technology during total knee arthroplasty (TKA) has been associated with more accurate component position and less blood loss. Yet to date, the risk of developing prosthetic joint infection (PJI) associated with computer navigation (CN) or robotic assistance (RA) has not been thoroughly evaluated. This study used propensity score-matching (PSM) in a large cohort of primary TKA patients to compare the rate of PJI following conventional TKA (TKA) versus CN-TKA and RA-TKA.

METHODS

We retrospectively reviewed 13,015 knees in 11,727 patients who underwent primary TKA at a single institution from 2018 to 2021. The cohort was stratified into TKA, CN-TKA, and RA-TKA groups. 1:1 PSM was applied to 11,834 patients. Propensity score-matching was performed using logistic regression accounting for age, sex, body mass index, Charlson Comorbidity Index (CCI) score, CCI components, and smoking status. Univariate and multivariable analyses were performed to evaluate differences in surgical time and PJI rate.

RESULTS

Significantly longer median operating times were noted in the RA-TKA group (14 minutes) compared to TKA (P < .001). The PJI rates among matched cohorts were similar among RA-TKA (0.3%), CN-TKA (0.3%), and conventional TKA (0.5%). Multivariable logistic regressions demonstrated that the use of robotic assistance (odds ratio (OR) = 0.5, P = .423) or computer navigation (OR = 0.61, P = .128) was not associated with increased risk of PJI when compared to conventional TKA.

CONCLUSIONS

Use of computer navigation and robotic assistance during primary TKA are associated with longer surgical times, but no difference in PJI frequency within 90 days of surgery.

Systematic review and meta-analysis of economic and healthcare resource utilization outcomes for robotic versus manual total knee arthroplasty

The introduction of robotics in orthopedic surgery has led to improved precision and standardization in total knee arthroplasty (TKA). Clinical benefits of robotic versus manual TKA have been well established; however, evidence for economic and healthcare resource utilization outcomes (HRU) is lacking. The primary objective of this study was to compare economic and HRU outcomes for robotic and manual TKA. The secondary objective was to explore comparative robotic and manual TKA pain and opioid consumption outcomes. Multi-database literature searches were performed to identify studies comparing robotic and manual TKA from 2016 to 2022 and meta-analyses were conducted. This review included 50 studies with meta-analyses conducted on 35. Compared with manual TKA, robotic TKA was associated with a: 14% reduction in hospital length of stay (P = 0.022); 74% greater likelihood to be discharged to home (P < 0.001); and 17% lower likelihood to experience a 90-day readmission (P = 0.043). Robotic TKA was associated with longer mean operating times (incision to closure definition: 9.27 min longer, P = 0.030; general operating time definition: 18.05 min longer, P = 0.006). No differences were observed for total procedure cost and 90-day emergency room visits. Most studies reported similar outcomes for robotic and manual TKA regarding pain and opioid use. Coupled with the clinical benefits of robotic TKA, the economic impact of using robotics may contribute to hospitals' quality improvement and financial sustainability. Further research and more randomized controlled trials are needed to effectively quantify the benefits of robotic relative to manual TKA.

Improved perioperative narcotic usage patterns in patients undergoing robotic-assisted compared to manual total hip arthroplasty

BACKGROUND

Robot-assisted total hip arthroplasty (RA-THA) improves accuracy in achieving the planned acetabular cup positioning compared to conventional manual THA (mTHA), but optimal dosage for peri-RA-THA and mTHA pain relief remains unclear. This study aimed to compare pain control with opioids between patients undergoing direct anterior approach THA with the use of a novel, fluoroscopic-assisted RA-THA system compared to opioid consumption associated with fluoroscopic-assisted, manual technique.

METHODS

Retrospective cohort analysis was performed on a consecutive series of patients who received mTHA and fluoroscopy-based RA-THA. The average amount of postoperative narcotics in morphine milligram equivalents (MME) given to each cohort was compared, including during the in-hospital and post-discharge periods. Analyses were performed on the overall cohort, as well as stratified by opioid-naïve and opioid-tolerant patients.

RESULTS

The RA-THA cohort had significantly lower total postoperative narcotic use compared to the mTHA cohort (103.7 vs. 127.8 MME; P < 0.05). This difference was similarly seen amongst opioid-tolerant patients (123.6 vs. 181.3 MME; P < 0.05). The RA-THA cohort had lower total in-hospital narcotics use compared to the mTHA cohort (42.3 vs. 66.4 MME; P < 0.05), consistent across opioid-naïve and opioid-tolerant patients. No differences were seen in post-discharge opioid use between groups.

CONCLUSIONS

Fluoroscopy-based RA-THA is associated with lower postoperative opioid use, including during the immediate perioperative period, when compared to manual techniques. This may have importance in rapid recovery protocols and mitigating episode burden of care.

Severity of Chronic Venous Insufficiency on Primary Total Knee Arthroplasty Outcomes

BACKGROUND

More than 700,000 people in the United States undergo total knee arthroplasty (TKA) each year. Chronic venous insufficiency (CVI) affects 5% to 30% of adults, sometimes resulting in leg ulceration. These CVI cases in TKAs have been associated with worse outcomes; however, we found no study differentiating CVI severity.

METHODS

This retrospective study analyzed TKA outcomes at one institution from 2011 to 2021 using patient-specific codes. Analyses included short-term complications (< 90 days postoperative), long-term complications (< 2 years), and CVI status (yes/no; simple/complex/unclassified). Complex CVI consisted of pain, ulceration, inflammation, and/or other complications. Revisions within 2 years and readmissions within 90 days post-TKA were assessed. Composite complications included short-term and long-term complications, revisions, and readmissions. Multivariable logistic regressions predicted complication (any/long/short) as a function of CVI status (yes/no; simple/complex) and potential confounding variables. Of 7,665 patients, 741 (9.7%) had CVI. Among CVI patients, 247 (33.3%) had simple CVI, 233 (31.4%) had complex CVI, and 261 (35.2%) had unclassified CVI.

RESULTS

There was no difference in CVI versus control in composite complications (P = .722), short-term complications (P = .786), long-term complications (P = .15), revisions (P = .964), or readmissions (P = .438) postadjustment. Composite complication rates were 14.0% without CVI, 16.7% with complex CVI, and 9.3% with simple CVI. Complication rates differed between simple and complex CVI (P = .035).

CONCLUSION

Overall, CVI did not affect postoperative complications versus control. Patients who have complex CVI are at higher risk for post-TKA complications compared to those who have simple CVI.

Robotic-Assisted Total Knee Arthroplasty Can Increase Frequency of Achieving Target Limb Alignment in Primary Total Knee Arthroplasty for Preoperative Valgus Deformity

Background

Robotic-assisted total knee arthroplasty (rTKA) has been shown to reduce the number of alignment outliers and to improve component positioning compared to manual TKA (mTKA). The primary purpose of this investigation was to compare the frequency of achieving target postoperative limb alignment and component positioning for rTKA vs mTKA.

Methods

A retrospective comparative study was performed on 250 patients undergoing primary TKA by 2 fellowship-trained arthroplasty surgeons. Surgeon A performed predominantly rTKA (103 cases) with the ROSA system (Zimmer Biomet, Warsaw, IN) and less frequently mTKA (44 cases) with conventional instrumentation. Surgeon B performed only mTKA (103 cases). Target limb alignment for surgeon A was 0° for all cases and for surgeon B was 2° varus for varus knees and 0° for valgus knees. Radiographic measurements were determined by 2 reviewers. Target zone was set at ± 2 degrees from the predefined target.

Results

When comparing rTKA to mTKA performed by different surgeons, there were no differences in the percentage within the target zone (57.28% vs 53.40%, P = .575), but rTKA did result in a greater percentage for cases with preoperative valgus (71.42% vs 44.12%, P = .031). Patient-reported Outcomes Measurement Information System Global-10 physical scores were statistically higher at both 3 (P = .016) and 6 months (P = .001) postoperatively for rTKA compared to mTKA performed by different surgeons.

Conclusions

Although experienced surgeons can achieve target limb alignment correction with similar frequency when comparing rTKA to mTKA for all cases, rTKA may achieve target limb alignment with more accuracy for preoperative valgus deformity.

Level of Evidence

Retrospective Cohort Study, Level III.

Comparison of conventional and robotic knee arthroplasty results: A retrospective observational study

OBJECTIVE

This study aimed to determine whether a standard anesthetic protocol consisting of combined spinal epidural anesthesia (CSEA) in conjunction with controlled hypotensive anesthesia (CHA), which was used for conventional total knee arthroplasty (cTKA), could provide equally effective anesthetic conditions for robotic total knee arthroplasty (rTKA).

METHODS

Data were collected from the medical records of 113 patients (median age=67 years; age range=55-84) who underwent elective unilateral cTKA (n=52) or rTKA (n=61) without a tourniquet from 2021 to 2023. The primary outcome measure was the rate of patients whose anesthetic method did not provide adequate motor and sensory block during the surgery and had to be converted to general anesthesia. The secondary outcome measure was to compare perioperative variables, including pain scores, analgesic consumption, blood loss, transfusions, and complications.

RESULTS

In 6 patients (11.5%) in group rTKA, it was required to convert CSEA to general anesthesia at 160-180 minutes due to the pain at the operative knee and/or to the movement of the operative leg during surgery compared to none / zero in group cTKA (P=.008). Motor and sensory blocks terminated earlier than the total surgery time in those patients. Mean total surgery time was significantly higher in group rTKA than in group cTKA (151.25 ± 24.51 (120-240) minutes vs. 116.72 ± 4.99 (105-125) minutes, P < .001). Total surgery times tended to decrease gradually in group rTKA after the 11th case, indicating a learning curve for surgical performance. Conversion to general anesthesia was required only in 1 patient after the 11th case compared to the previous 5 patients. Mean pain scores and rescue analgesic consumption were higher in group rTKA at postoperative 0 hour and between 0 and 4 hours (P < .05) but similar at the following time points (P > .05). Blood loss, transfusion, and complication rates were similar (P > .05). Hospital discharge times were higher in group rTKA (P < .05).

CONCLUSION

Although our standard CSEA protocol failed due to the regression of motor and sensory block during surgery in 11.5% of patients in rTKA, the CSEA technique combined with controlled hypotensive anesthesia provided similar anesthetic conditions in the remaining patients in group rTKA as in group cTKA. The CSEA may be considered an effective and safe anesthetic method for rTKA if interventions are applied to extend the duration of the CSEA for this novel surgical technique.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Robotic-assisted technology does not influence functional outcomes among obese and morbidly obese total knee arthroplasty patients

PURPOSE

Despite benefits of total knee arthroplasty (TKA) on function and quality of life, obese patients have less improved functional outcomes following TKA compared to their normal weight counterparts. Furthermore, obesity is a risk factor for aseptic loosening and revision surgery following TKA. With known benefits of robotic-assisted TKA (RaTKA) in precision and patient satisfaction, we aimed to evaluate the differences in patient reported outcome and early complication rates for patients undergoing RaTKA versus conventional TKA among patients of varying BMI groups.

METHODS

This study was a retrospective cohort study of patients who underwent conventional versus RaTKA. Patients were grouped by BMI range (< 30 kg/m2, 30-40 kg/m2, and > 40 kg/m2). Patient-reported outcomes were measured by Oxford Knee Scores and 12-Item Short Form Survey scores preoperatively, 6-month, 1-year, and 2-year postoperatively. Mixed-effects linear models were built for each patient-reported outcome to assess the interaction between type of surgery and BMI while adjusting for known confounders such as demographic variables.

RESULTS

A total of 350 patients (n = 186 RaTKA, n = 164 conventional TKA) met inclusion criteria. SF-12 physical scores were significantly higher at 2-year follow-up among non-obese patients compared to obese and morbidly obese patients (p = 0.047). There was no statistically significant interaction between the type of surgery performed (RaTKA versus conventional TKA) and obesity regarding their effects on patient reported outcomes.

CONCLUSIONS

This study demonstrates no differences in functional outcomes among patients undergoing RaTKA compared to conventional TKA. Furthermore, obesity had no significant effect on this association.

LEVEL OF EVIDENCE

III.

Robotic-assisted total knee arthroplasty is not associated with increased risk of postoperative deep vein thrombosis

PURPOSE

Prolongation of operation time due to registration and pin insertion has been reported with robotic-assisted total knee arthroplasty (RATKA), and there has been concern about an increase in the postoperative incidence of deep vein thrombosis (DVT). In this study, we compared the incidence of DVT after RATKA with that after conventional manual TKA (mTKA).

METHODS

This consecutive retrospective series included 141 knees that underwent primary TKA using the Journey II system. The CORI robot was used. There were 60 RATKAs and 81 mTKAs. Doppler ultrasound was performed in all patients on postoperative day 7 to determine whether DVT was present.

RESULTS

The operation time was longer in the RATKA cohort (99.5 min vs 78.0 min, p < 0.001). The overall incidence of DTV was 43.9% (62/141 knees), all of which were asymptomatic. There was no significant difference in incidence of DVT between RATKA and mTKA (50.0% vs 39.5%, p = 0.23). Use of the robot did not affect the incidence of DVT following TKA (odds ratio 1.02, 95% confidence interval 0.40-2.60; p = 0.96).

CONCLUSION

The incidence of DVT was not significantly different between RA-TKA and mTKA. Multiple logistic regression indicated that RATKA is not associated with increased risk of postoperative DVT.

LEVEL OF EVIDENCE

IV.

Intraoperative Fractures Sustained During Total Knee Arthroplasty: A Critical Analysis Review

» While the occurrence of postoperative periprosthetic fractures around total knee arthroplasties (TKAs) are well reported, little is known about intraoperative fractures that occur during TKA. Intraoperative fractures during TKA can occur in femur, tibia, or patella. It is a rare complication with an incidence of 0.2% to 4.4%.» Risk factors of periprosthetic fractures include osteoporosis, anterior cortical notching, chronic corticosteroid use, advanced age, female sex, neurologic disorders, and surgical technique.» Fractures can potentially occur at any stage of the TKA including exposure, bone preparation, placement of trial components, cementation, insertion of the final components, and seating of the polyethylene insert. Forced flexion during trialing increases the risk for patella fracture, tibial plateau, or tubercle fractures especially when there is under resection of the bone.» Management guidelines for these fractures are lacking with current options being observation, internal fixation, the use of stems and augments, increasing constraint of the prosthesis, implant revision, and modifying the postoperative rehabilitation.» Finally, the outcomes of intraoperative fractures are not well reported in the literature.

Postoperative scores for robot-assisted and conventional total knee arthroplasty: A meta-analysis

Background

Knee osteoarthritis is the most common joint disease globally. As obesity and age rates continue to rise in the U.S., the demand for total knee arthroplasty (TKA) is expected to grow significantly by 2030. Advanced techniques such as robotic-assisted (RA-TKA) aim to address this growing concern and improve patient quality-of-life. Since utilization of RA-TKA increased from 2010 to 2018, it is important to compare RA-TKA to conventional TKA (C-TKA) performance. This study compares RA-TKA to C-TKA in patient-reported WOMAC scores and objective range of motion (ROM) scores in eligible short-term (one-year or less) and long-term (one-year to fifteen-years) postoperative follow-up studies.

Methods

A systematic review using the PubMed database was performed to identify articles including RA-TKA, CA-TKA, C-TKA, WOMAC scores, and ROM scores.

Results

Between RA-TKA and C-TKA, weighted analysis found significant effects in short-term (15.45, 95% CI: 4.96-25.94) and long-term (2.62, 95% CI: 0.62-4.61) WOMAC scores.

Conclusion

As approximately 7-20% of C-TKA surgeries result in poor subjective outcomes, and with revision rates and the demand for TKA set to rise, our analysis suggests that patient quality-of-life and cost effectiveness may be significantly improved by RA-TKA over C-TKA.

Surgical accuracy and clinical outcomes of image-free robotic-assisted total knee arthroplasty

BACKGROUND

The development of total knee arthroplasty (TKA) for knee osteoarthritis (OA) has a good reputation for its effectiveness in reducing joint pain and improving range of motion. We aimed to review our early results using the image-free robotic-assisted technology in knee arthroplasty.

METHODS

A total of 71 patients suffering from end-stage OA knee receiving TKA operated by robotic-assisted surgery between the years 2018 and mid-2021 were recruited. Clinical and radiological outcomes were compared with age and sex-matched control group (conventional TKA).

RESULTS

The radiological outcome showed significantly more postoperative lower limb alignment outliers in conventional side than robotic-assisted sides. Postoperative knee scores were similar among both groups. Robotic-assisted TKA required a longer implantation time but a shorter hospital stay.

CONCLUSION

Robotic-assisted TKA achieved a lower rate of mechanical axis Outlier in the coronal and sagittal plane with a shorter hospital stay. Yet both methods achieve a similar functional outcome.

Reduced Early Revision Surgery and Medical Complications in Computer-assisted Knee Arthroplasty Compared With Non-computer-assisted Arthroplasty

BACKGROUND

Computer assistance can help surgeons achieve mechanical accurate alignment, but the clinical effect of this technology in different arthroplasty types remains controversial because of conflicting functional outcomes, revision rates, and complication rates. The goal of this study was to compare 90-day medical complications and 1 and 2-year revision surgeries after computer-assisted patellofemoral arthroplasty, unicompartmental knee arthroplasty (CA-UKA), bicompartmental knee arthroplasty (CA-BKA), and total knee arthroplasty (CA-TKA) with non-computer-assisted procedures.

METHODS

A retrospective cohort analysis was conducted using the Mariner data set of the PearlDiver Patient Records Database from 2010 to 2018. Current Procedural Terminology codes were used to identify patients who underwent patellofemoral arthroplasty, unicompartmental knee arthroplasty, bicompartmental knee arthroplasty, and total knee arthroplasty with or without computer assistance for osteoarthritis. All included patients were followed up for 2 years. Univariate and multivariable analyses were conducted.

RESULTS

On multivariable analysis, revision within 1 year was decreased in patients who underwent computer-assisted patellofemoral arthroplasty (odds ratio [OR]: 0.541, P = 0.031), CA-UKA (OR: 0.798, P = 0.019), and computer-assisted bicompartmental knee arthroplasty (OR: 0.186, P = 0.025) compared with the same surgeries without technology assistance. CA-TKA had decreased odds of revision for aseptic loosening at 2 years (OR: 0.789, P < 0.001). CA-UKA and CA-TKA had decreased risk of overall 90-day medical complications (OR: 0.838, P < 0.001; OR: 0.903, P < 0.001, respectively) and major complications (OR: 0.750, P = 0.004; OR: 0.822, P < 0.001, respectively).

DISCUSSION

Complication rates and revision surgeries for all arthroplasty types were equivalent or more favorable when computer assistance was used during surgery. Our results quantify some early benefits to using computer assistance in total and partial knee arthroplasties.

Complications and downsides of the robotic total knee arthroplasty: a systematic review

PURPOSE

The purpose of this systematic review is to describe the complications and downsides of robotic systems in total knee arthroplasty (TKA).

METHODS

A comprehensive search according to the PRISMA guidelines was performed across PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Scopus, and Google Scholar from inception until December 2021. All articles of any study design directly reporting on complications and downsides of the robotic system in TKA were considered for inclusion. Risk of bias assessment was performed for all included studies using the Cochrane risk of bias and MINORS score.

RESULTS

A total of 21 studies were included, consisting of 4 randomized controlled trials, 7 prospective studies and 10 retrospective studies. Complications of the robotic system were pin-hole fracture, pin-related infection, iatrogenic soft tissue and bony injury, and excessive blood loss. While, downsides were longer operative duration, higher intraoperative cost, learning curve and aborting a robotic TKA due to different reasons. Iatrogenic injuries were more common in the active robotic system and abortion of the robotic TKA was reported only with active robotic TKA.

CONCLUSION

Robotic TKA is associated with certain advantages and disadvantages. Therefore, surgeons need to be familiar with the system to use it effectively. Widespread adoption of the robotic system should always be evidence-based.

LEVEL OF EVIDENCE

IV.

Postoperative respiratory depression in patients on sublingual buprenorphine: a retrospective cohort study for comparison between postoperative continuation and discontinuation of buprenorphine

Background

We tested the hypothesis that patients who continued buprenorphine postoperatively experience postoperative respiratory depression less frequently than those who discontinued buprenorphine.

Methods

This is a retrospective cohort study of patients who were on buprenorphine preoperatively. The primary outcome was postoperative respiratory depression as defined by respiratory rate < 10/minute, oxygen saturation (SpO₂) < 90%, or requirement of naloxone for 48 h postoperatively. The secondary outcome was the composite of postoperative respiratory complications. The associations between postoperative buprenorphine continuation and respiratory depression and respiratory complications were estimated using separate multivariable logistic regression models, including demographic, intraoperative characteristics, and preoperative buprenorphine dose as covariates.

Results

Postoperative buprenorphine continuation was not associated with postoperative respiratory depression (adjusted odds ratio (OR), 1.11, 95% confidence interval (CI), 0.61 to 1.99, P=0.72). In subanalysis stratified by the preoperative buprenorphine dose, buprenorphine continuation was not associated with postoperative respiratory depression either when preoperative buprenorphine dose was high (≥16 mg daily) or low (<16 mg daily). Postoperative buprenorphine continuation was associated with lower incidence of postoperative respiratory complications (adjusted OR, 0.43, 95% CI, 0.21 to 0.86, P=0.02).

Conclusions

Continuing buprenorphine was not associated with respiratory depression, but it was associated with a lower incidence of respiratory complications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40981-022-00535-2.

A comparison of utilization and short-term complications of technology-assisted versus conventional total knee arthroplasty

Background

While technology-assisted total knee arthroplasty (TA-TKA) improves implant positioning, whether it confers improved clinical outcomes remains inconclusive. We sought to examine national TA-TKA utilization trends and to compare outcomes between TA-TKA and unassisted TKA (U-TKA).

Methods

Patients who underwent primary, elective TKA from 2010 to 2018 were identified using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Demographic, perioperative, and 30-day outcomes were collected. Patients were stratified on the basis of whether they underwent TA-TKA, which included computer navigation and robotics, or U-TKA. The proportion of patients undergoing TKA using TA-TKA was calculated. One-to-one propensity-score matching paired patients undergoing TA-TKA or U-TKA. Independent samples t-tests and Mann–Whitney U tests were used to compare continuous variables, and chi-squared tests were used to compare categorical variables.

Results

Of the 402,284 TKA patients, 10,429 (2.6%) cases were performed using TA-TKA. Comparing the unmatched TA-TKA and U-TKA groups, race (p < 0.001), smoking status (p = 0.050), baseline functional status (p < 0.001), and body mass index (BMI) (p < 0.001) significantly differed. Propensity-score matching yielded 8633 TA-TKA and U-TKA pairs. The TA-TKA cohort had shorter hospital length of stay (LOS) (2.7 ± 2.5 versus 2.8 ± 1.9 days, p = 0.017) but similar operative times (92.4 ± 33.4 versus 92.6 ± 39.8 min, p = 0.670). Compared with the U-TKA group, the TA-TKA group had lower major complication (7.6% versus 9.4%, p < 0.001) and transfusion (3.9% versus 5.1%, p < 0.001) rates and higher rates of discharge to home (73.9% versus 70.4%, p < 0.001). Reoperation and readmission rates did not significantly differ between groups.

Conclusions

TA-TKA utilization remains low among orthopedic surgeons. Compared with U-TKA, TA-TKA yielded improved perioperative and 30-day outcomes. Nonetheless, surgeons must consider the benefits and drawbacks of TA-TKA when determining the proper surgical technique and technology for each patient.

Level III evidence

Retrospective cohort study.

Computer-Navigated and Robotic-Assisted Total Knee Arthroplasty: Increasing in Popularity Without Increasing Complications

BACKGROUND

Data on the clinical impact of computer navigation (CN) and robotic assistance (RA) in total knee arthroplasty (TKA) are mixed. This study aims to describe modern utilization trends in CN-TKA, RA-TKA, and traditionally-instrumented (TD) TKA and to assess for differences in postoperative complications and opioid consumption by procedure type.

METHODS

A national database was queried to identify primary, elective TKA patients from 2015 to 2020. Trends in procedural utilization rates were assessed. Differences in 90-day postoperative complications and inpatient opioid consumption were assessed. Multivariate regression analyses were performed to account for potential confounders.

RESULTS

Of the 847,496 patients included, 49,317 (5.82%) and 24,460 (2.89%) underwent CN-TKA and RA-TKA, respectively. CN-TKA utilization increased from 5.64% (2015) to 6.41% (2020) and RA-TKA utilization increased from 0.84% (2015) to 5.89% (2020). After adjusting for confounders, CN-TKA was associated with lower periprosthetic joint infection (P = .001), pulmonary embolism (P < .001), and acute respiratory failure (P = .015) risk compared to traditional (TD) TKA. RA-TKA was associated with lower deep vein thrombosis (P < .001), myocardial infarction (P = .013), and pulmonary embolism (P = .001) risk than TD-TKA. Lower postoperative day 1 opioid usage was seen with CN-TKA and RA-TKA than TD-TKA (P < .001). Lower postoperative day 0 opioid consumption was also seen in RA-TKA (P < .001).

CONCLUSION

From 2015 to 2020, there was a relative 13.7% and 601.2% increase in CN-TKAs and RA-TKAs, respectively. This trend was associated with reductions in hospitalization duration, postoperative complications, and opioid consumption. These data support the safety of RA-TKA and CN-TKA compared to TD-TKA. Further investigation into the specific indications for these technology-assisted TKAs is warranted.

The Impact of Surgeon Variability on Patient-Reported Outcome Measures, Length of Stay, Discharge Disposition, and 90-Day Readmission in TKA

BACKGROUND

Studies involving total knee arthroplasty (TKA) have focused on patient-related factors as drivers of outcomes. Although some studies have investigated surgeon and/or surgery-level factors (i.e., approach, volume), the measure of variance in postoperative outcomes across surgeons following TKA has not been determined. The aim of the current study was to evaluate the relationship between the surgeon and 1-year patient-reported outcome measures, the length of stay, the discharge disposition, and 90-day readmission after TKA, as well as the differences in these variables among surgeons.

METHODS

Data were prospectively collected for 5,429 patients who underwent TKA at a large health-care system with 36 surgeons between 2016 and 2018. Likelihood ratio tests were performed to investigate the relationship between surgeon and the 1-year Knee injury and Osteoarthritis Outcome Score (KOOS)-Pain subscale, KOOS-Physical Function Shortform (KOOS-PS), KOOS for Joint Replacement (KOOS-JR), patient acceptable symptom state (PASS), length of stay, discharge disposition, and 90-day readmission. The minimal clinically important difference (MCID) was used to assess meaningful outcomes. Variable importance was determined by the Akaike information criterion (AIC) increase, using ordinal and binary-response mixed-effect models.

RESULTS

There was a significant association between surgeon and KOOS-Pain (p < 0.001), KOOS-PS (p = 0.001), KOOS-JR (p < 0.001), PASS (p = 0.024), length of stay (p < 0.001), discharge disposition (p < 0.001), and 90-day readmission (p < 0.001). When modeling 1-year KOOS-Pain (AIC increase, 15.6), KOOS-PS (AIC increase, 6.8), KOOS-JR (AIC increase, 13.5), PASS (AIC increase, 1.9), length of stay, and discharge disposition, the surgeon variable contributed more to the 1-year outcome than some patient-level factors (e.g., body mass index, Charlson Comorbidity Index). The difference between the highest and lowest median probabilities of attaining the same value for the KOOS-Pain (11.2%), KOOS-PS (9.4%), KOOS-JR (11.8%), PASS (5.9%), length of stay (46.6%), discharge disposition (22.8%), and readmission (13.1%) indicated surgeon-level variability.

CONCLUSIONS

Surgeon-related factors may be stronger contributors to the 1-year patient-reported outcome measures and length of stay than patient characteristics emphasized in the literature. Current findings have suggested variability in patient-reported outcome measures, length of stay, discharge location, and 90-day readmission among surgeons. Surgeon variability should be considered when model-fitting in the setting of TKA.

LEVEL OF EVIDENCE

Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Analysis of New Orthopaedic Technologies in Large Database Research

Improvements in orthopaedic surgery go hand in hand with technological advances. The present article outlines the historical and current uses of large databases and registries for the evaluation of new orthopaedic technologies, providing insights for future utilization, with robotic-assisted surgery as the example technology.

Understanding rates, risk factors, and complications associated with manipulation under anesthesia after total knee arthroplasty (TKA): An analysis of 100,613 TKAs

BACKGROUND

Considering the growing adoption of technology-assisted total knee arthroplasties (TKA), previous database studies evaluating post-operative stiffness may be outdated. The present study aimed to: (1) evaluate the incidence of manipulation under anesthesia (MUA) after primary TKA; (2) determine independent risk factors for MUA; and (3) assess complications after MUA.

METHODS

Primary TKAs, with at least 6-month follow-up, were identified from the Florida State Inpatient Database (January 2016-June 2018) and linked to outpatient records from the Florida State Ambulatory Surgery and Services Database. Multivariable regression analyses were performed to compare patient factors and complications (e.g., mechanical, non-mechanical, infectious) associated with MUA, while adjusting for baseline demographics, comorbidities, use of robotic- and computer-technologies, time to MUA (0-3, 3-12, or >12 months), and need for repeat MUA (one-time vs >1).

RESULTS

The MUA rate was 2.8% (2821 of 100,613). Being younger, a woman, Black or Hispanic; having private or self-pay insurance; and conventional TKA were associated with significantly higher odds of undergoing MUA. Higher rates of mechanical complications and acute posthemorrhagic anemia were observed in the MUA cohort. Time to MUA, repeat MUA, and baseline demographics were not associated with complication rates among the MUA cohort.

CONCLUSION

Overall, 1 in 36 patients underwent MUA after primary TKA. Several non-modifiable patient characteristics, such as Black or Hispanic race, female sex, and younger age were associated with an increased risk of MUA. However, technology-assisted TKA might help to decrease the risk of MUA.

Use of intraoperative technology in total knee arthroplasty is not associated with reductions in postoperative pain

PURPOSE

Our systematic review and meta-analysis sought to assess how technology-assistance impacts (1) post-operative pain and (2) opioid use in patients undergoing primary total knee arthroplasty (TKA).

METHODS

Four online databases were queried for studies published up to October 2021 that reported on pain and opioid usage between technology-assisted and manual TKA (mTKA) patients. Mantel-Haenszel (M-H) models were utilized to calculate pooled mean difference (MDs) and 95% confidence interval (CIs). Subgroup analyses were conducted to isolate robotic-arm assisted (RAA) and computed-assisted navigation (CAN) cohorts. Risk of bias was assessed for all included non-randomized studies with the Methodological Index for Non-Randomized Studies (MINORS) tool. For the randomized control trials included in our study, the Detsky scale was applied.

RESULTS

Our analysis included 31 studies, reporting on a total of 761,300 TKAs (mTKA: n = 753,554; Computer-Assisted Navigation (CAN): n = 1,309; Robotic-Arm Assisted (RAA): n = 6437). No differences were demonstrated when evaluating WOMAC (MD: 0.00, 95% CI - 0.69 to 0.69; p = 1.00), KSS (MD: 0.01, 95% CI - 1.46 to 1.49; p = 0.99), KOOS (MD - 2.91, 95% CI - 6.17 to 0.34; p = 0.08), and VAS (MD - 0.54, 95% CI - 1.01 to - 0.007; p = 0.02) pain scores between cohorts. There was mixed evidence regarding how opioid consumption differed between TKA techniques.

CONCLUSION

The present analysis demonstrated no difference in terms of pain across a variety of utilized patient-reported pain measurements. However, there were mixed results regarding how opioid consumption varied between manual and technology-assisted cohorts, particularly in the immediate post-operative period.

LEVEL OF EVIDENCE

III.

Association of Opioid Use Disorder on Postoperative Outcomes Following Lumbar Laminectomy: A Nationwide Retrospective Analysis of the Medicare Population

BACKGROUND

Research focused on the association of opioid use disorder (OUD) on postoperative outcomes in patients undergoing primary lumbar laminectomy is lacking. This study aims to observe the impact of OUD on (1) hospital length of stay (LOS), (2) readmission rates, (3) medical complications, and (4) health care expenditures.

METHODS

A retrospective query was performed using a nationwide claims database from January 2005 to March 2014 for all patients who underwent lumbar laminectomy, yielding a total of 131,635 patients. The study cohort included 3515 patients with OUD, while 128,120 patients served as the comparison cohort. Multivariate binomial logistic regression analyses were used to determine the association of OUD on readmission rates and medical complications, whereas Welch's t tests were used to compare LOS and health care expenditures. A P value less than 0.001 was considered statistically significant.

RESULTS

Patients with OUD undergoing lumbar laminectomy had significantly longer hospital LOS (3.68 vs 1.13 days, P < 0.0001). Readmission rates were significantly higher (14.57% vs 7.39%, OR: 1.73, P < 0.0001) in patients who had an OUD. The study cohort was found to have higher incidence and odds (32.36% vs 9.76%, OR: 3.53, P < 0.0001) of 90-day medical complications and total global 90-day episode of care reimbursement rates ($13,635.81 vs $8131.20, P < 0.0001) compared with their counterparts.

CONCLUSIONS

This study demonstrates OUD to be associated with longer hospital LOS, increased rates of 90-day readmissions, medical complications, and health care expenditures following lumbar laminectomy.

LEVEL OF EVIDENCE: 3

CLINICAL RELEVANCE

Results indicate that OUD is associated with worse outcomes following lumbar laminectomy.

Patella Strength Characteristics in Cemented vs Press-fit Implants: A Biomechanical Analysis of Initial Stability

Background

Patellar resurfacing is routinely performed during total knee arthroplasty to reduce pain associated with patellofemoral osteoarthritis. With 3-dimensional ingrowth materials readily available, the present study aimed to evaluate if cemented polyethylene (CP) patellar buttons conferred higher ultimate load to failure than press-fit metal-backed (PF) buttons in axial compression.

Material and methods

Ten matched cadaveric and 20 composite patellae were resurfaced and implanted with either a PF or CP button. Biomechanical testing using an MTS machine was performed to measure the force required to generate a periprosthetic patella fracture. Mean load to failure and load to failure per 1-mm patellar thickness were compared with a paired and independent samples Students’ t-test for the cadaveric and composite patellae, respectively.

Results

The average load to failure for the matched cadaveric patellae with PF implants was significantly lower than that for patellae with CP buttons (4082.05 N vs 5898.37 N, P = .045). The average load to failure for composite patella with PF implants was significantly higher than that for composite patellae with CP implants (6004.09 N vs 4551.40 N, P = .001). The mean load to failure per 1-mm patellar thickness was also significantly higher for composite patellae with PF implants (263.80 N/mm vs 200.37 N/mm, P = .001).

Conclusion

Cadaveric patellae with cemented implants had a significantly higher ultimate load to failure in axial compression than press-fit patella. However, this result was reversed in the composite model. Exploration of biological and composite model properties could provide further insight into patellar implant selection during total knee arthroplasty.

Primary total knee arthroplasty assisted by computed tomography-free navigation for secondary knee osteoarthritis following massive calcium phosphate cement packing for distal femoral giant-cell bone tumor treatment: a case report

BACKGROUND

Giant cell tumor of bone (GCTB) is an intermediate tumor commonly arising from the epiphysis of the distal femur and proximal tibia. Standard GCTB treatment is joint-preserving surgery performed using thorough curettage and the filling of the cavity with allo-, auto-, polymethyl methacrylate (PMMA), or synthetic bone graft. Calcium phosphate cement (CPC) is an artificial bone substitute, which has the benefit of being able to adjust defects, consequently inducing immediate mechanical strength, and promoting biological healing. Secondary osteoarthritis may occur following GCTB treatment and may need additional surgery if severe. However, details regarding surgery for secondary osteoarthritis have not been fully elucidated. There are no reports on the use of total knee arthroplasty (TKA) for the treatment of secondary osteoarthritis following CPC packing. The insertion of an alignment rod is a standard procedure in TKA; however, it was difficult to perform in this case due to CPC. Therefore, we used a computed tomography (CT)-free navigation system to assist the distal femur cut. This study presents a knee joint secondary osteoarthritis case following CPC packing for GCTB curettage that was treated with standard TKA.

CASE PRESENTATION

A 67-year-old Japanese woman, who was previously diagnosed with left distal femur GCTB and was treated by curettage and CPC packing 7 years ago, complained of severe knee pain. Left knee joint plain radiography revealed Kellgren and Lawrence (K-L) grade 4 osteoarthritis without evidence of tumor recurrence. Therefore, she was scheduled for TKA. There are no reports on the cutting of a femoral condyle surface with massive CPC with accurate alignment. Because it is difficult to insert the alignment rod intramedullary and cut the femoral condyle with CPC, we planned CT-free navigation-guided surgery for accurate bone cutting using an oscillating tip saw system to prevent CPC cracks. We performed standard TKA without complications, as planned. Postoperative X-ray showed normal alignment. Knee Society Knee Score (KSKS) and Knee Society Function Score (KSFS) ameliorated from 27 and 29 to 64 and 68, respectively The patient can walk without a cane postoperatively.

CONCLUSION

There was no report about the surface TKA guided by CT-free navigation after primary GCT surgery with CPC. We believe that this case report will help in planning salvage surgery for secondary osteoarthritis after CPC packing.

Trends of Utilization and 90-Day Complication Rates for Computer-Assisted Navigation and Robotic Assistance for Total Knee Arthroplasty in the United States From 2010 to 2018

BACKGROUND

Computer-assisted navigation (CAN) and robotic assistance (RA) for total knee arthroplasty (TKA) are gaining in popularity. The purpose of this study is to update the literature on United States technology-assisted TKA trends of national utilization, regional utilization, and 90-day complication rates requiring readmission.

METHODS

Patients who underwent primary, elective TKA between 2010 and 2018 were retrospectively identified in the PearlDiver All Payer Claims Database (PearlDiver Technologies Inc.). TKAs were classified as conventional, CAN, or RA based on International Classification of Diseases nineth or tenth revision and Current Procedural Technology codes. Annual rates and regional trends of each type of TKA were reported. Ninety-day complications requiring readmission for each group were captured. Multivariable logistic regression was used to identify odds ratios (OR) for all-cause readmission based on TKA modality.

RESULTS

Of the 1,307,411 elective TKAs performed from 2010 to 2018, 92.8% were conventional, and 7.7% were technology-assisted (95.2% CAN and 4.9% RA). RA-TKA had the greatest increase in utilization (+2204%). The Western region had the highest utilization of technologies for TKA, while the Midwestern region had the lowest. Ninety-day postoperative complications requiring readmission were highest for conventional TKA and lowest for RA-TKA. RA-TKA (OR 0.68; 97.5% confidence interval 0.56-0.83, P < .001) and CAN-TKA (OR 0.93; 97.5% confidence interval 0.88-0.97, P < .05) had significantly lower odds of all-cause 90-day complications requiring readmission than conventional TKA.

CONCLUSION

Utilization of RA-TKA and CAN-TKA continues to rise across the United States. The use of these technologies is associated with a lower OR of readmission within 90 days postoperatively.

[Application and research progress of robotic-arm in total knee arthroplasty]

OBJECTIVE

To summarize the application and research progress of robotic-arm in total knee arthroplasty (TKA).

METHODS

Relevant literature at home and abroad was extensively reviewed to analyze the advantages and disadvantages of robotic-arm assisted TKA (RATKA).

RESULTS

Accurate reconstruction of lower extremity alignment and rotation alignment, accurate osteotomy and implant prosthesis in TKA are very important to improve the effectiveness and prolong the life of the prosthesis. Traditional TKA deviations occur in key links such as osteotomy due to operator's operation. RATKA solves the above problems to a certain extent and can assist accurate osteotomy and implant prosthesis, and protect the soft tissues around the knee joint. Patients' satisfaction after RATKA is high, and the operator's learning curve is shorter, which improves the efficiency of the operation. But it also has disadvantages such as prolonged operation time, increased complications and medical costs.

CONCLUSION

Preliminary clinical application studies have shown that RATKA has satisfactory effectiveness, but its definite advantages compared with traditional TKA need to be confirmed by a large number of randomized controlled trials and long-term follow-up.