Surgeons Experience Greater Physiologic Stress and Strain in the Direct Anterior Approach Than the Posterior Approach for Total Hip Arthroplasty.

INTRODUCTION: The direct anterior approach (DAA) and posterior approach (PA) for total hip arthroplasty (THA) have advantages and disadvantages, but their physiologic burden to the surgeon has not been quantified. This study was conducted to determine whether differences exist in surgeon physiological stress and strain during DAA in comparison to PA. METHODS: We evaluated a prospective cohort of 144 consecutive cases (67 DAA and 77 PA). There were five, high-volume, fellowship-trained arthroplasty surgeons who wore a smart-vest that recorded cardiorespiratory data while performing primary THA DAA or PA. Heart rate (beats/minute), stress index (correlates with sympathetic activations), respiratory rate (respirations/minute), minute ventilation (liters/min), and energy expenditure (calories) were recorded, along with patient body mass index and operative time. Continuous data was compared using T-tests or Mann Whitney U tests, and categorical data was compared with Chi-square or Fischer's exact tests. RESULTS: There were no differences in patient characteristics. Compared to PA, performing THA via DAA had a significantly higher surgeon stress index (17.4 versus 12.4; P < 0.001), heart rate (101 versus 98.3; P = 0.007), minute ventilation (21.7 versus 18.7; P < 0.001), and energy expenditure per hour (349 versus 295; P < 0.001). However, DAA had a significantly shorter operative time (71.4 versus 82.1; P = 0.001). CONCLUSION: Surgeons experience significantly higher physiological stress and strain when performing DAA compared to PA for primary THA. This study provides objective data on energy expenditure that can be factored into choice of approach, case order, and scheduling preferences, and provides insight into the work done by the surgeon.

Debridement, Antibiotics, and Implant Retention in Unicompartmental Knee Arthroplasty Infection.

BACKGROUND: This multicenter study sought to further investigate the method and outcome of debridement, antibiotics, and implant retention (DAIR) for the management of unicompartmental knee periprosthetic joint infection (PJI). METHODS: This retrospective study was performed on 52 patients who underwent DAIR for PJI of a unicompartmental knee arthroplasty (UKA) across 4 academic medical centers, all performed by fellowship-trained arthroplasty surgeons. Patient demographics, American Society of Anesthesiologists score, infecting organism, operative data, antibiotic data, and success in infection control at 1 year were collected. RESULTS: The average time from index surgery to diagnosis of PJI was 11.1 weeks (range, 1.4 to 48). There was no correlation between time of diagnosis and success at 1 year (R = 0.09, P = .46). There was an association between surgical synovectomy and the eradication of infection (R = 0.28, P = .04). Overall, there was an 80.8% (42 of 52) infection-controlled success rate at 1 year from the DAIR procedure. All DAIR failures went on to require another procedure, either 1-stage (2 of 10) or 2-stage (8 of 10) revision to total knee arthroplasty (TKA). Of the DAIR successes, 6 (14.3%) went on to require conversion to TKA for progression of arthritis within 5 years. CONCLUSIONS: This study demonstrates that DAIR is a safe and moderately effective procedure in the setting of acute PJI of UKA across institutions, with a success rate consistent with DAIR for TKA. The data suggest that a wide exposure and thorough synovectomy be incorporated during the DAIR UKA to improve the likelihood of successful eradication of PJI at the 1-year mark. LEVEL OF EVIDENCE: Level III.

Interpreting the Current Literature on Outcomes of Robotic-Assisted Versus Conventional Total Knee Arthroplasty Using Fragility Analysis: A Systematic Review and Cross-Sectional Study of Randomized Controlled Trials.

BACKGROUND: Fragility analysis is a method of further characterizing outcomes in terms of the stability of statistical findings. This study assesses the statistical fragility of recent randomized controlled trials (RCTs) evaluating robotic-assisted versus conventional total knee arthroplasty (RA-TKA versus C-TKA). METHODS: We queried PubMed for RCTs comparing alignment, function, and outcomes between RA-TKA and C-TKA. Fragility index (FI) and reverse fragility index (RFI) (collectively, "FI") were calculated for dichotomous outcomes as the number of outcome reversals needed to change statistical significance. Fragility quotient (FQ) was calculated by dividing the FI by the sample size for that outcome event. Median FI and FQ were calculated for all outcomes collectively as well as for each individual outcome. Subanalyses were performed to assess FI and FQ based on outcome event type and statistical significance, as well as study loss to follow-up and year of publication. RESULTS: The overall median FI was 3.0 (interquartile range, [IQR] 1.0 to 6.3) and the median reverse fragility index was 3.0 (IQR 2.0 to 4.0). The overall median FQ was 0.027 (IQR 0.012 to 0.050). Loss to follow-up was greater than FI for 23 of the 38 outcomes assessed. CONCLUSIONS: A small number of alternative outcomes is often enough to reverse the statistical significance of findings in RCTs evaluating dichotomous outcomes in RA-TKA versus C-TKA. We recommend reporting FI and FQ alongside P values to improve the interpretability of RCT results.

Return to Sport After Unicompartmental Knee Arthroplasty and Patello-Femoral Arthroplasty.

BACKGROUND: Data on sports/physical activity participation following unicompartmental knee arthroplasty (UKA) and patello-femoral arthroplasty (PFA) is variable and limited. The purpose of this study was to assess participations, outcomes, and limitations in sports following UKA and PFA. METHODS: Patients who underwent UKA and PFA at a single institution from 2015 to 2020 were surveyed on sports participation before and after surgery. Data was correlated with perioperative patient characteristics and outcome scores. Among 776 patients surveyed, 356 (50%) patients responded. Of respondents, 296 (83.1%) underwent UKA, 44 (12.6%) underwent PFA, and 16 (4.5%) underwent both UKA/PFA. RESULTS: Activity participation rates were 86.5, 77.3, and 87.5% five years prior, and 70.9, 61.4, and 75% at one year prior to UKA, PFA, and UKA/PFA, respectively. Return to sports rates were 81.6, 64.7, and 62.3% at mean 4.6 years postoperatively, respectively. The most common activities were recreational walking, swimming, cycling, and golf. Patients returned to a similar participation level for low-impact activities, whereas participation decreased for intermediate- and high-impact activities. Patients participating in activities had higher postoperative Knee Injury and Osteoarthritis Outcome Score Joint Replacement (P < .001), 12-Item Short Form Physical Component Score (P = .045) and Mental Component Score (P = .012). Activity restrictions were reported among 25, 36.4, and 25% of UKA, PFA, and UKA/PFA patients, respectively, and were more commonly self-imposed than surgeon-directed. CONCLUSIONS: Though UKA patients' postoperative sports participation may improve compared to one year preoperatively, participation for patients surgically treated for isolated osteoarthritis is decreased compared to 5 years preoperatively and varies among patient subsets.

The Efficacy of Preoperative Video-Based Opioid Counseling on Postoperative Opioid Consumption After Total Knee Arthroplasty: A Prospective Randomized Controlled Trial.

BACKGROUND: There are myriad strategies to reduce opioid consumption after total knee arthroplasty (TKA). Recent studies have suggested that preoperative counseling may reduce opioid use after a variety of orthopedic procedures. The purpose of this study was to investigate whether preoperative video-based patient education regarding opioid use and abuse reduces opioid consumption after TKA. METHODS: In this prospective randomized controlled trial, patients were randomized before TKA to either receive preoperative video-based counseling or not. Counseling involved a pretaped 5-minute video that educated patients on statistics regarding the "opioid epidemic" and discussed safe use and alternatives to opioids after TKA. There were no significant differences in baseline patient demographics between groups. All patients received a similar multimodal perioperative pain management protocol and completed a daily diary for 2 weeks postoperatively. Diary records measured pain levels using a visual analog score, opioid consumption, side effects experienced, and patient opinion and satisfaction regarding their pain control. RESULTS: Patients in the counseling group consumed significantly less morphine milligram equivalents on postoperative days 0 to 3 (78.8 versus 106.1, P = .020) and in week one postoperatively (129.9 versus 180.7, P = .028), with a trend of less consumption over 2 weeks postoperatively (186.9 versus 239.1, P = .194). There were no significant differences in the number of patients requiring refills, side effects, or daily pain levels between the 2 groups. CONCLUSIONS: This study found significantly decreased opioid consumption within the first week after TKA in patients who received preoperative video counseling.

Completion of Patient-Reported Outcome Measures Improved With Use of a Mobile Application in Arthroplasty Patients: Results From a Randomized Controlled Trial.

BACKGROUND: The collection of patient-reported outcome measures (PROMs) has historically been reported as costly and time-consuming, with low compliance rates that may impact reimbursement. Little research has reported the effects of mobile applications to support PROMs collection following arthroplasty. METHODS: Secondary analysis of data from a multicenter randomized controlled trial was performed. Patients undergoing knee and hip arthroplasty were randomized to utilize a smartphone-based care management platform (app) for self-directed rehabilitation and completed joint-specific PROMs (Hip Dysfunction and Osteoarthritis Outcome Score, Joint Replacement or Knee Injury and Osteoarthritis Score, Joint Replacement) via the application at prescribed intervals or on paper during clinic visits. Control patients received practice standard of care, and completed PROMs via emailed hyperlink or during clinic visits following lower limb arthroplasty. Overall, 455 patients underwent knee arthroplasty procedures (245 control, 210 app group) and 380 underwent total hip arthroplasty (206 control, 174 app group). Compliance with expected PROMs completion was calculated through one year postoperatively. RESULTS: Compliance was higher in the app group preoperatively in both knee (98.1 versus 86.9%, P < .0001) and hip cohorts (96.0 versus 88.4%, P = .008), and postoperatively, including at one year (knees, 72.2 versus 53.7%, P < .0001; hips, 71.1 versus 49.2%, P < .0001). On log-binomial regressions, intervention arm was the strongest predictor of completion of all PROMs, where app users undergoing knee (Relative Risk 2.039, 95% confidence interval (CI) 1.595 to 2.607, P < .000) and hip arthroplasty (2.268 95% CI 1.742 to 2.953, P < .0001) were more likely to be compliant at all timepoints. The majority of patients in the app group, including those over 65 years of age, completed PROMs using the application as opposed to paper methods. CONCLUSIONS: A smartphone mobile application that engages patients during recovery after knee and hip joint arthroplasty improved compliance with completion of preoperative and postoperative PROMs compared to other electronic and paper methods.

Joint line position change in primary total knee arthroplasty: a radiographic analysis comparing conventional and robotic techniques.

PURPOSE: Joint line (JL) position change in total knee arthroplasty (TKA) may alter knee biomechanics and impact function. The purpose of this study was to compare the change in JL position between robotic-assisted TKA (RA-TKA) and conventional TKA (C-TKA). METHODS: A retrospective, radiographic analysis was conducted of patients who underwent RA-TKA and C-TKA to compare JL position change. JL position was measured in consecutive RA-TKAs and C-TKAs performed by four fellowship-trained arthroplasty surgeons. Statistical analysis was done utilizing t-tests and Mann Whitney U tests, with statistical significance being defined as a p value < 0.05. RESULTS: Six hundred total RA-TKAs and 400 total C-TKAs were included in the analysis. There were no significant differences in patient baseline characteristics such as body mass index, range of motion, and tibiofemoral coronal alignment. RA-TKAs were associated with an average of 0.04 (2.2) mm JL position change, and C-TKAs were associated with an average 0.5 (3.2) mm JL position change (p = 0.030). There were inter-surgeon differences when comparing the change in JL position for RA-TKAs and C-TKAs between the four participating surgeons. CONCLUSION: RA-TKA leads to better preservation of the JL position than C-TKA, and this seems to be dependent on the arthroplasty surgeon's preferences and techniques during TKA. Whether this statistically significant difference is clinically relevant needs to be further investigated.

Association Between Digitally Provided Education and 90-Day Return to Sexual Activity Following Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Contemporary total knee arthroplasty patients have increased expectations of returning to predisease function, including sexual activity (SA). The purpose of this study was to determine whether patients using a digital care management platform (DCMP) were more likely to have a higher rate and frequency of return to SA. METHODS: We conducted an exploratory analysis of a prospective, multicenter, randomized controlled trial that enrolled patients undergoing total knee arthroplasty. A total of 304 patients were randomized to a DCMP (n = 119) providing preoperative and postoperative education regarding return to SA or standard postoperative care (control group; n = 185). Return to SA, assessed via questionnaire, patient-reported outcome measures, Timed Up and Go test, single leg stance, active range of motion and need for manipulation under anesthesia were assessed at 90 days postoperatively. RESULTS: More patients in the DCMP group returned to SA compared to control at 90 days (58.4 versus 39.6%, P = .018); however, the control group resumed SA sooner (33.1 versus 42.0 days, P = .023). Patients who returned to SA were younger (61.6 versus 65.9 year), more often men (56 versus 35%) (P < .001), higher performing on the Timed Up and Go and single leg stance tests (P < .001), and had greater active range of motion (P = .007). There were no differences in patient-reported outcome measures or need for manipulation under anesthesia between patients that returned to SA and those who did not. CONCLUSIONS: More patients using a DCMP resumed SA at 90 days; however, patients in the control group returned to SA sooner. Those who returned to SA were younger, possessed greater physical function, and were more often men.

Robotic-Assisted Total Knee Arthroplasty Has Similar Rates of Prosthetic Noise Generation as Conventional Total Knee Arthroplasty.

Background: Noise has been reported to occur with relatively high frequency after conventional total knee arthroplasty (C-TKA), and this may impact the incidence of patient satisfaction and function. The purpose of this study was to compare the rate of patient-reported prosthetic noise generation after robotically-assisted TKA (RA-TKA) and C-TKA. Methods: A retrospective study was conducted of unilateral primary RA-TKAs and C-TKAs performed between 2018 and 2021. Patients completed a survey consisting of 4 Likert scale questions related to prosthetic noise generation and Knee Injury and Osteoarthritis Score Joint Replacement and Forgotten Joint Score were assessed prospectively preoperatively and at a minimum of 1-year of clinical follow-up. Statistical analysis was done utilizing T-tests and chi-square tests, with statistical significance defined as a P-value < .05. Results: One hundred sixty-two RA-TKAs and 320 C-TKAs with similar baseline characteristics and functions were included. There were no significant differences in hearing or feeling grinding, popping, clicking, or clunking (40.7% vs 38.1%; P = .647) between groups. Most RA-TKAs and C-TKAs were not dissatisfied regarding noise generation (70.4% vs 73.1%; P = .596). In both cohorts, patients who reported noise generation had lower average Forgotten Joint Scores (45.5 vs 66.1; P < .001) and lower postoperative Knee Injury and Osteoarthritis Score Joint Replacement scores (72.0 vs 81.4; P < .001) than those who did not experience noise generation. Conclusions: While RA-TKA may facilitate soft tissue balancing, there were no differences in prosthetic noise generation between RA-TKA and C-TKA. However, those who experience implant-generated noise have lower functional outcome scores.

Robotic-Assisted Total Knee Arthroplasty: What are Patients' Perspectives, Understanding and Expectations?

BACKGROUND: The rate of using robotic-assisted total knee arthroplasty (RA-TKA) has increased markedly. Understanding how patients view the role of robotics during total knee arthroplasty (TKA) informs shared decision making and facilitate efforts to appropriately educate patients regarding the risks and benefits of robotic assistance. METHODS: A self-administered questionnaire was completed by 440 potential TKA patients at the time of their surgery scheduling. Participants answered 25 questions regarding RA-TKA, socioeconomic factors, and their willingness to pay (WTP) for RA-TKA. Logistic regressions were used to determine if population characteristics and surgeon preferences influenced the patients' perceptions of RA-TKA. RESULTS: There were 39.7% of respondents who said that they had no knowledge regarding RA-TKA. Only 40.7% of participants had expressed a desire for RA-TKA to be used. There were 8.7% who were WTP extra for the use of RA-TKA. Participants believed that the main 3 benefits of RA-TKA compared to conventional methods were: more accurate implant placement (56.2%); better results (49.0%); and faster recovery (32.1%). The main 3 patient concerns were harm from malfunction (55.2%), reduced surgeon role in the procedure (48.1%), and lack of supportive research (28.3%). Surgeon preference of RA-TKA was associated with patient's willingness to have RA-TKA (odds ratio 4.60, confidence interval 2.98-7.81, P < .001), and with WTP extra for RA-TKA (odds ratio 2.05, confidence interval: 1.01-4.26, P = .049). CONCLUSION: Patient knowledge regarding RA-TKA is limited. Nonpeer-reviewed online information may make prospective TKA candidates vulnerable to misinformation and aggressive advertising. The challenge for orthopaedic surgeons is to re-establish control and reliably educate patients about the proven advantages and disadvantages of this emerging technology.

Unicompartmental Knee Arthroplasty Is Cost-Effective in an Outpatient Setting.

INTRODUCTION: Increasingly, unicompartmental knee arthroplasty (UKA) is being performed on an outpatient basis, with the growing utilization of ambulatory surgery centers (ASCs). The purpose of this study was to compare the costs of UKAs performed in an ASC to UKAs done in a hospital, either on an outpatient or inpatient basis. METHODS: This study involved three matched groups, each with 50 consecutive patients, undergoing UKA either on an outpatient basis in an ASC or a community hospital, or who were admitted overnight to the same community hospital. Identical perioperative analgesic regimens and care protocols were used in each group. The primary outcomes evaluated included direct facility costs. Secondary outcomes were postoperative complications and readmissions. RESULTS: Average age, gender ratio, and comorbidities were similar in all three cohorts. Only two patients in the study experienced complications and these were without secondary adverse consequences. Mean costs were substantially reduced when UKAs were performed in an ASC ($9,025) compared to a community hospital on either an outpatient ($12,032) or inpatient basis ($14,542). CONCLUSION: UKA can be safely performed in the outpatient setting, in appropriately selected patients, at substantial cost savings, particularly when performed in an ASC.

Image-Free Robotic-Assisted Total Knee Arthroplasty Results in Quicker Recovery but Equivalent One-Year Outcomes Compared to Conventional Total Knee Arthroplasty.

BACKGROUND: Few studies have addressed whether robotic-assisted total knee arthroplasty (RA-TKA) significantly impacts functional outcomes. This study was conducted to determine whether image-free RA-TKA improves function compared to conventional total knee arthroplasty (C-TKA), performed without the utilization of robotics or navigation, using the Minimal Clinically Important Difference (MCID) and Patient Acceptable Symptom State (PASS) as measures of meaningful clinical improvement. METHODS: A multicenter propensity score-matched retrospective study was conducted of RA-TKA using an image-free robotic system and C-TKA cases at an average follow-up of 14 months (range, 12 months to 20 months). Consecutive patients who underwent primary unilateral TKA and had a preoperative and postoperative Knee Injury and Osteoarthritis Outcome Score-Joint Replacement (KOOS-JR) were included. The primary outcomes were the MCID and PASS for KOOS-JR. 254 RA-TKA and 762 C-TKA patients were included, with no significant differences in sex, age, body mass index, or comorbidities. RESULTS: Preoperative KOOS-JR scores were similar in the RA-TKA and C-TKA cohorts. Significantly greater improvement in KOOS-JR scores were achieved at 4 to 6 weeks postoperatively with RA-TKA compared to C-TKA. While the mean 1-year postoperative KOOS-JR was significantly higher in the RA-TKA cohort, no significant differences were found in the Delta KOOS-JR scores between the cohorts, when comparing preoperative and 1-year postoperative. No significant differences existed in the rates of MCID or PASS being achieved. CONCLUSION: Image-free RA-TKA reduces pain and improves early functional recovery compared to C-TKA at 4 to 6 weeks, but functional outcomes at 1 year are equivalent based on the MCID and PASS for KOOS-JR.

An orthopaedic intelligence application successfully integrates data from a smartphone-based care management platform and a robotic knee system using a commercial database.

PURPOSE: To evaluate the feasibility of using a smartphone-based care management platform (sbCMP) and robotic-assisted total knee arthroplasty (raTKA) to collect data throughout the episode-of-care and assess if intra-operative measures of soft tissue laxity in raTKA were associated with post-operative outcomes. METHODS: A secondary data analysis of 131 patients in a commercial database who underwent raTKA was performed. Pre-operative through six week post-operative step counts and KOOS JR scores were collected and cross-referenced with intra-operative laxity measures. A Kruskal-Wallis test or a Wilcoxon sign-rank was used to assess outcomes. RESULTS: There were higher step counts at six weeks post-operatively in knees with increased laxity in both the lateral compartment in extension and medial compartment in flexion (p < 0.05). Knees balanced in flexion within < 0.5 mm had higher KOOS JR scores at six weeks post-operative (p = 0.034) compared to knees balanced within 0.5-1.5 mm. CONCLUSION: A smartphone-based care management platform can be integrated with raTKA to passively collect data throughout the episode-of-care. Associations between intra-operative decisions regarding laxity and post-operative outcomes were identified. However, more robust analysis is needed to evaluate these associations and ensure clinical relevance to guide machine learning algorithms.

Surgeons Experience More Physiologic Stress and Strain During Revision Than Primary Total Joint Arthroplasty.

BACKGROUND: Revision total knee arthroplasty (rTKA) and total hip arthroplasty (rTHA) procedures are more complex than primary TKA and THA, but their physiologic burden to the surgeon has not been quantified. While rTKA and rTHA have longer operative times, it is unknown whether differences exist in stress and strain compared to primary TKA and primary THA. The study was conducted to elicit whether differences exist in surgeon physiological response while performing rTKA and rTKA compared to primary TKA and primary THA. METHODS: We evaluated a prospective cohort study of 70 consecutive cases (23 primary TKAs, 12 primary THAs, 16 rTKAs, and 19 rTHAs). Two high-volume fellowship-trained arthroplasty surgeons wore a smart vest that recorded cardiorespiratory data while performing primary THA, primary TKA, rTHA, and rTKA. Heart rate (beats/minute), stress index (correlates with sympathetic activation), respiratory rate (respirations/minute), minute ventilation (L/min), and energy expenditure (Calories) were collected for every case, along with patient body mass index (kilograms/meter2) and working operative time (minutes). T-tests were used to assess for differences between the two groups. RESULTS: Compared to primary TKA, performing rTKAs had a significantly higher surgeon stress index (17 versus 15; P = .035), heart rate (104 versus 99; P = .007), energy expenditure per case (409 versus 297; P = .002), and a significantly lower heart rate variability (11 versus 12; P = .006). Compared to primary THA, performing rTHA had a significantly higher energy expenditure per case (431 versus 307; P = .007) and trended towards having a higher surgeon stress index (16 versus 14; P = .272) and a lower heart rate variability (11 versus 12; P = .185), although it did not reach statistical significance. CONCLUSION: Surgeons experience higher physiological stress and strain when performing rTKA and rTHA compared to primary TKA and primary THA. This study provides objective data on what many surgeons feel and should promote further research on the specific stress and strain felt by surgeons who perform revision arthroplasty procedures.

Manipulation Under Anesthesia is Safe After Cementless Total Knee Arthroplasty: A Multicenter Study.

BACKGROUND: Cementless total knee arthroplasty (TKA) is thought to facilitate durable, biological fixation between the bone and implant. However, the 4-12 weeks required for osseointegration coincides with the optimal timeframe to perform a manipulation under anesthesia (MUA) if a patient develops postoperative stiffness. This study aims to determine the impact of early MUA on cementless fixation by comparing functional outcomes and survivorship of cementless and cemented TKAs. METHODS: A consecutive series of patients who underwent MUA for postoperative stiffness within 90 days of primary, unilateral TKA at 2 academic institutions between 2014 and 2018 were identified. Cases involving extensive hardware removal were excluded. Cementless TKAs undergoing MUA (n = 100) were propensity matched 1:1 to cemented TKAs undergoing MUA (n = 100) using age, gender, body mass index, and year of surgery. Both groups had comparable baseline Knee Injury and Osteoarthritis Outcome Scores (KOOS), Short Form (SF)-12 Physical, and SF-12 Mental scores. MUA-related complications as well as postoperative KOOS and SF-12 scores were compared. RESULTS: MUA-related complications were equivalently low in both groups (P = .324), with only 1 patella component dissociation in the cementless group. No tibial or femoral components acutely loosened in the perioperative period. Postoperative KOOS (P = .101) and SF-12 Mental scores (P = .380) were similar between groups. Six-year survivorship free from any revision after MUA was 98.0% in both groups (P = 1.000). CONCLUSION: Early postoperative MUA after cementless TKA was not associated with increased MUA-related complications or worse patient-reported outcomes compared to cemented TKA. Short-term survivorship was also comparable, suggesting high durability of the bone-implant interface.

UKA with a handheld robotic device results in greater surgeon physiological stress than conventional instrumentation.

PURPOSE: Poor ergonomics and acute stress can impair surgical performance and cause work-related injuries. Robotic assistance may optimize these psychophysiological factors during UKA. This study compared surgeon physiologic stress and ergonomics during robotic-assisted UKA (rUKA) and conventional UKA (cUKA). METHODS: Cardiorespiratory and postural data from a single surgeon were recorded during 30 UKAs, (15 rUKAs, 15 cUKAs). Heart rate (HR), HR variability, respiratory rate (RR), minute ventilation and calorie expenditure were used to measure surgical strain. Intraoperative ergonomics were assessed by measuring flexion/extension/rotation of the neck and lumbar spine, and shoulder abduction/adduction. RESULTS: Mean operative time was 32.0 ± 7 min for cUKA and 45.9 ± 9 min for rUKA (p < 0.001). Mean neck flexion was - 23.4° ± 13° for rUKA and - 49.1° ± 18 for cUKA (p < 0.001), while mean lumbar flexion was - 20.3° ± 30° for rUKA and - 0.4° ± 68° for cUKA (p = 0.313). Mean lumbar flexion was similar; however, a significantly greater percentage of time was spent in lumbar flexion > 20° during cUKA. Bilateral shoulder abduction was significantly higher for rUKA. Mean calorie expenditure was 154 cal for rUKA and 89.1 cal for cUKA (p < 0.001). Mean HR was also higher for rUKA (88.7 vs. 84.7, p = 0.019). HR variability was slightly lower for rUKA (12.4) than for cUKA (13.4), although this did not reach statistical significance (p = 0.056). No difference in RR or minute ventilation was observed. CONCLUSION: rUKA resulted in less neck flexion but increased shoulder abduction, heart rate, and energy expenditure. The theoretical ergonomic and physiologic advantages of robotic assistance using a handheld sculpting device were not realized in this study. LEVEL OF EVIDENCE: II.

Moving beyond radiographic alignment: applying the Wald Principles in the adoption of robotic total knee arthroplasty.

The use of robotics in total knee arthroplasty (TKA) is growing at an exponential rate. Despite the improved accuracy and reproducibility of robotic-assisted TKA, consistent clinical benefits have yet to be determined, with most studies showing comparable functional outcomes and survivorship between robotic and conventional techniques. Given the success and durability of conventional TKA, measurable improvements in these outcomes with robotic assistance may be difficult to prove. Efforts to optimize component alignment within two degrees of neutral may be an attainable but misguided goal. Applying the "Wald Principles" of rationalization, it is possible that robotic technology may still prove beneficial, even when equivalent clinical outcomes as conventional methods, if we look beyond the obvious surrogate measures of success. Robotic systems may help to reduce inventory, streamline surgical trays, enhance workflows and surgical efficiency, optimize soft tissue balancing, improve surgeon ergonomics, and integrate artificial intelligence and machine learning algorithms into a broader digital ecosystem. This article explores these less obvious alternative benefits of robotic surgery in the field of TKA.

Pin-Related Complications in Computer Navigated and Robotic-Assisted Knee Arthroplasty: A Systematic Review.

BACKGROUND: Computer-assisted navigation (CAN) and robotic-assisted (RA) knee arthroplasty procedures carry unique risks of tracking pin-related complications. This systematic review aimed to quantitatively assess the incidence, timing, treatment, and clinical outcomes of all tracking pin-related complications following CAN and RA knee arthroplasty. METHODS: A systematic review was performed using PubMed, Cochrane Central and Scopus databases. All clinical studies that documented pin-related complications associated with the use of CAN or RA for total or partial knee arthroplasty were included. Descriptive statistics were analyzed when data were available. RESULTS: Thirty-six studies were included: 18 case reports (25 cases) and 18 randomized controlled trials, cohort studies and case series i.e., non-case reports (7,336 cases). The most common pin-related complication among case reports was fracture (n = 22; 81%). The overall rate of pin-related complications among non-case reports was 1.4%. The intraoperative and postoperative complication with the highest incidence were pin dislodgement (0.6%) and superficial pin site infections (0.6%), respectively. Most postoperative complications were related to the tibial site (69%). All complications were effectively treated and resolved at follow-up. CONCLUSION: Pin-related complications following CAN and RA knee arthroplasty are relatively uncommon. While pin loosening, superficial infections and fractures have been most commonly documented, other complications such as vascular injury, myositis ossificans, and osteomyelitis can also occur. The potential for pin-related complications should be considered by arthroplasty surgeons, especially during early stages of adoption. Further studies investigating patient risk factors for pin-related complications are warranted.

Navigated and Robot-Assisted Technology in Total Knee Arthroplasty: Do Outcome Differences Achieve Minimal Clinically Important Difference?

BACKGROUND: In total knee arthroplasty (TKA), computer-assisted navigation (N-TKA) and robotic-assisted methods (RA-TKA) are intended to increase precision of mechanical and component alignment. However, the clinical significance of published patient-reported outcome measure (PROM) differences in comparison to conventional TKA (C-TKA) is unknown. METHODS: A systematic review was performed to identify all studies reporting perioperative PROMs for either primary N-TKA or RA-TKA with a C-TKA comparison cohort with a minimum 1-year follow-up. Relative improvements in PROMs for the two cohorts were compared to published minimal clinically important difference (MCID) values. RESULTS: After systematic review, 21 studies (N = 3,214) reporting on N-TKA and eight studies (N = 1,529) reporting on RA-TKA met inclusion criteria. Eighteen of 20 studies (90%) reported improved radiographic outcomes with N-TKA relative to C-TKA; five of five studies reported improved radiographic outcomes with RA-TKA relative to C-TKA. Five of 21 studies (24%) reported statistically significant greater improvements in clinical PROMs for N-TKA relative to C-TKA, whereas only two (10%) achieved clinical significance relative to MCID on a secondary analysis. One of 8 studies (13%) reported statistically significant greater improvements in PROMs for RA-TKA relative to C-TKA, whereas none achieved clinical significance relative to MCID on a secondary analysis. No studies reported a significant difference in revision rates. CONCLUSION: While most studies comparing RA-TKA and N-TKA with C-TKA demonstrate improved radiographic alignment outcomes, a minority of studies reported PROM differences that achieve clinical significance. Future studies should report data and be interpreted in the context of clinical significance to establish patient and surgeon expectations for emerging technologies.