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.

Technology in Total Knee Arthroplasty in 2023.

Over the past few decades, instrumentation and techniques for total knee arthroplasty have evolved from conventional manual tools to a wide range of technologies, including calibrated guides for accurate bone cuts and alignment, smart tools, dynamic intraoperative sensors for soft tissue balancing, patient-specific guides, computer navigation, and robotics. This review is intended to provide an overview of the latest advancements in total knee arthroplasty technology, address potential challenges and solutions related to the application of these technologies, and explore their limitations.

Robotic-Assisted Total Knee Arthroplasty Results in Shorter Navigation Working Time With Similar Clinical Outcomes Compared to Computer-Navigated Total Knee Arthroplasty.

BACKGROUND: Early clinical data is important in the appraisal of newly introduced robotic-assisted surgery (RAS) systems in total knee arthroplasty (TKA). However, there are few studies to date comparing one-year clinical outcomes between RAS and computer-assisted navigation (CAS), the forerunner in reducing alignment outliers. The aim of this study was to determine if there was a difference between these two groups in early clinical outcomes, including functional outcome and patient-reported outcome measures (PROMs). METHODS: A total of 158 propensity score-matched patients who underwent primary TKA with either CAS or RAS were retrospectively analyzed. Perioperative outcomes (navigation time, length of stay, complications, readmissions, transfusions, and technical failure), as well as functional outcome measures (range of motion, sit to stand test, timed up and go test, single leg stance test, calf raises, and step count), and patient-reported outcome measures (Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score, 12-item Short Form Survey, Forgotten Joint Score-12, and satisfaction) were compared between those who underwent CAS and those who underwent RAS. RESULTS: Navigation time was shorter in the RAS group compared to the CAS group (mean difference, 15.4 minutes; P < 0.001). There were two complications reported in the CAS group (1 patellar clunk, 1 periprosthetic joint infection), but none in the RAS group. There were no other readmissions, transfusions, or technical failures in either group. Postoperatively, there were no clinical differences in function between groups. Clinically meaningful improvement in PROMs was observed in both groups, with no differences. CONCLUSION: The use of RAS resulted in shorter navigation time compared to CAS in TKA. No other differences were observed in early clinical outcomes between patients who underwent RAS and CAS.

Accelerometer-based portable navigation, a faster guide compared to computer-assisted navigation in bilateral total knee arthroplasty-a randomized controlled study.

PURPOSE: There are limited studies in the literature comparing the alignment accuracy of  the large console, imageless, computer-assisted navigation (CAN) and portable, hand-held, accelerometer-based navigation (ABN) in total knee arthroplasty (TKA).  This study was aimed to compare the operative time, blood loss, radiological, clinical and functional outcomes between CAN- and ABN-guided bilateral TKA. METHODS: From Jan 2016 to Dec 2017, 50 patients who underwent bilateral TKA were randomized to undergo either CAN-guided or ABN-guided TKA. Tourniquet time and blood loss were recorded, and intra-op complications were noted. Post-op radiological outcomes at 2 weeks were compared between the groups. The clinical and functional outcomes using the American Knee Society Scores (KSS) and Oxford Knee Score (OKS) were recorded pre-operatively and post-operatively at 3, 6, 12 months and at the end of the study with a minimum follow-up of 48 months. RESULTS: Both groups were well-matched in terms of patient demographic parameters. The mean surgical time per knee was significantly lower in the ABN group (54.5 ± 5.6 min) compared to the CAN group (61.7 ± 13.7 min; p < 0.01). Mean blood loss per knee in the ABN group was 592.1 ± 245.3 mL compared to 682.8 ± 322.0 in the CAN group (p = 0.11). In the ABN group, the mean post-op mechanical axis was 1.2 ± 3.2° (vs 1.5 ± 2.2° in the CAN group, p 0.6), the frontal femoral angle was 88.8 ± 2.3° (vs 88.8 ± 1.8° in the CAN group, p 1.0) and frontal tibial angle was 90.1 ± 1.6° (vs 89.7 ± 1.1° in the CAN group, p 0.14). At 48 month follow-up, the mean functional KSS in the ABN group was 89.0 ± 5.7 (vs 88.1 ± 4.5 in the CAN group, p 0.37) and the mean OKS was 40.5 ± 2.8 (vs 39.6 ± 3.2 in the CAN group, p 0.12). CONCLUSION: Portable, hand-held ABN offers alignment accuracy and functional outcomes in TKA similar to that with CAN, with a reduced duration of surgery. There was no advantage of either of the techniques in terms of clinical or functional outcomes at 48 month follow-up. LEVEL OF EVIDENCE 1.

Total Hip Arthroplasty Imageless Navigation Does Not Reduce 90-Day Adverse Events or Five-Year Revisions in a Large National Cohort.

BACKGROUND: Computer navigation is an increasingly utilized technology that is considered with total hip arthroplasty (THA). However, the evidence to support this practice is mixed. The current study leveraged a large national administrative database to compare 90-day adverse events as well as 5-year all-cause revision and dislocation rates following THA performed with and without imageless navigation. METHODS: From 2010 to 2020, a large national database was queried for THA cases performed for osteoarthritis. Cases with or without imageless navigation were matched at 1:4 based on age, sex, and Elixhauser Comorbidity Index (ECI) score. Ninety-day adverse events were assessed and compared with multivariate analyses. Five-year incidence of revision and dislocation were also assessed between cohorts. RESULTS: Use of THA imageless navigation increased from 2010 (2.5% of cases) to 2020 (5.5% of cases; P < .001). After matching, 11,990 THA patients with navigation and 47,948 without navigation were identified. Overall, 90-day adverse events were observed in 7.0% of the population. Multivariate analysis controlling for age, sex, and ECI demonstrated a difference in only one 90-day adverse event; wound dehiscence, which had higher odds in the navigation group (odds ratio, 1.60, P < .001). At 5 years, revisions for the navigated group were higher (4.4 versus 3.6%: P = .006), while dislocations were not significantly different. CONCLUSION: THA imageless navigation was not found to be associated with improved 90-day postoperative adverse events or differences in the 5-year rates of revision or dislocation. The current data were unable to identify clear advantages of this evolving technology for primary THA.

Anterior cortical line of femur and tibia is more accurate than mid-shaft line to determine knee extension angle relative to sagittal mechanical axis during total knee arthroplasty.

BACKGROUND: Accurate assessment of knee extension angle relative to sagittal mechanical axis (SMA) during TKA is usually obtained by computer navigation. Whether the lines along anterior cortex of distal femur and proximal tibia in short-knee imaging are accurate in determining knee extension angle has not been investigated. METHODS: A prospective study was conducted on 106 patients (116 knees) who underwent primary TKA. After complete anesthetization, the leg was elevated 30° and short-knee lateral fluoroscopy was performed. The angles between the anterior cortical line (ACL), and between the mid-shaft line (MSL) of the femur and tibia, were measured. After surgical exposure and bony registration into OrthoPilot navigation system, the leg was elevated again and degree of knee extension was recorded. The angles determined using three methods were compared. RESULTS: The mean extension angle observed by OrthoPilot (5.0° ± 6.8°, range -8°-25°) was not different from ACL method (5.3° ± 7.0°, range -8.1°-24.3°) (p = 0.811), but higher than MSL method (1.7° ± 7.1°, range -13.2°-18.1°) (p < 0.001). The mean absolute difference of ACL method from OrthoPilot was 0.2° ± 1.8° (range 0.0°-5.0°; 95%CI 0.0°-2.0°), and MSL method from OrthoPilot was 3.2° ± 2.6° (range 0.1°-8.2°; 95%CI 2.7°-3.7°). Measurement differences within 2° were found in 83.6% (97/116) and 37.9% (44/116) in the ACL and MSL method respectively (p < 0.001). CONCLUSION: ACL of femur and tibia in a short-knee imaging is more accurate than MSL for determining knee extension angle relative to SMA. ACL can be assessed intraoperatively as the anterior cutting surface of distal femur after bone cut during TKA and the palpable anterior tibial crest. This ACL measurement in a pre- or postoperative radiograph provides the minimal detectable change of 3.5° and helpful in clinical research that requires high precision measurement.

[High tibial osteotomy with computer navigation for medial gonarthritis]. / Sravnitel'nye rezul'taty lecheniya medial'nogo gonartrita metodom vysokoi tibial'noi osteotomii s ispol'zovaniem komp'yuternoi navigatsii.

OBJECTIVE: To study significance of computer navigation for improving clinical and radiological results of medial gonarthritis treatment compared to non-invasive methods of lower limb axis correction control. MATERIAL AND METHODS: The study included 73 patients who were divided into 2 groups. The main group included 40 patients, the control group - 33 patients. In the main group, high tibial osteotomy was performed using computer navigation, in the control group - using non-invasive techniques. Clinical assessment was carried out according to the KSS, KOOS and VAS scales. We assessed the main reference angles of the lower limb considering X-ray data. RESULTS: Both groups were characterized by postoperative improvement of clinical results according to various scales. Computer navigation provided higher accuracy in most cases. We focused on target correction of 3° valgus. CONCLUSION: High tibial osteotomy with computer navigation or non-invasive techniques is an effective treatment method for medial gonarthritis. There are no significant differences in clinical results according to the KSS and KOOS scales, as well as X-ray data after correction. We found significant differences in VAS scores.

Fracture through tracking pin sites following a robotic-assisted total knee arthroplasty.

The use of computer-navigated, robotic-assisted total knee arthroplasty (TKA) is expanding as the result of widespread efforts to improve the precision of implant placement and to restore mechanical, anatomic, and kinematic alignment. The procedure requires placement of femoral and tibial pins to mount the robotic tracking system. Fractures through tracking pin sites following robotic-assisted TKA are rare; only 30 cases have been reported to our knowledge. It is probable that this complication will become more frequent as the use of robotic-assisted TKAs continues to grow. We report the case of a 67-year-old female who suffered a fracture of the femur through two pin sites 3 months after a robotic-assisted TKA. We believe that this report is the first case in the radiologic literature. Our case demonstrates some of the difficulties of recognizing this complication and raises questions about appropriate post-operative imaging.

Navigation and robotics improved alignment compared with PSI and conventional instrument, while clinical outcomes were similar in TKA: a network meta-analysis.

PURPOSE: To achieve the desired alignment more accurately and improve postoperative outcomes, new techniques such as computer navigation (Navigation), patient-specific instruments (PSI) and surgical robots (Robot) are applied in Total Knee Arthroplasty (TKA). This network meta-analysis aims to compare the radiological and clinical outcomes among the above-mentioned techniques and conventional instruments (CON). METHODS: A PRISMA network meta-analysis was conducted and study protocol was published online at INPLASY (INPLASY202060018). Three databases (PubMed, EMBASE and Cochrane) were searched up to June 1, 2020. Randomised controlled trials (RCTs) comparing any two of the four techniques were included. A Bayesian network meta-analysis was performed focusing on radiological and clinical outcomes. The odds ratio (OR) or mean difference (MD) in various outcomes were calculated, and the interventions were ranked by the surface under the cumulative ranking area (SUCRA) value. RESULTS: Seventy-three RCTs were included, with a total of 4209 TKAs. Navigation and Robot could significantly reduce the occurrence of malalignment and malposition compared with PSI and CON, and Navigation could obtain higher medium-and-long-term KSS knee scores than CON. Robot had the greatest advantage in achieving the desired alignment accurately, followed by Navigation; Navigation had the greatest advantage in the KSS score. CONCLUSION: Navigation and Robot did improve the accuracy of alignment compared with PSI and conventional instrument in TKA, but the above four techniques showed no clinical significance in postoperative outcomes. LEVEL OF EVIDENCE: I.

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.

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.

Occupational Hazards to the Joint Replacement Surgeon: How Can Technology Help Prevent Injury?

Occupational hazards pose varying threats to the joint replacement surgeon. Musculoskeletal pain due to the repetitive nature of performing joint arthroplasty is felt daily by most surgeons. The purpose of this paper is to offer a basic introduction and demonstrate the many ways technology utilized during total joint arthroplasty can help mitigate common occupational hazards for the arthroplasty surgeon. This paper guides readers through the evolution and drivers behind technology in joint arthroplasty, describes several technologies currently available, and discusses how certain aspects of this technology may work to improve surgeon and patient outcomes. We review how advanced technologies in arthroplasty may reduce physical and mental demand, improve reproducibility, and decrease complications. The decision to utilize advanced technology in joint arthroplasty is ultimately made on an individual level after careful consideration of available literature.

Avoiding Femoral Canal Instrumentation in Computer-Assisted Total Knee Arthroplasty With Contemporary Blood Management Had Minimal Differences in Blood Loss and Transfusion Rates Compared to Conventional Techniques.

BACKGROUND: Computer-assisted surgery that does not utilize femoral canal instrumentation is theorized to have less blood loss. However, there is a paucity of data on this, particularly in the era of tranexamic acid use. We sought to analyze the association of computer navigation with total calculated blood loss and transfusion rate in patients undergoing primary total knee arthroplasty (TKA). METHODS: We identified 14,890 patients who underwent unilateral primary TKA at a single institution from 2016 to 2020. Computer-assisted surgery in the form of an accelerometer or robotics was utilized in 4,165 TKAs (28%). Drains were utilized in 4,860 TKAs (32%). We used multivariate logistic regression analysis to determine if computer navigation reduced the rate of blood transfusion and linear regression analysis to determine the impact of computer navigation on blood loss. RESULTS: In total, 542 patients (3.6%) underwent a transfusion. The average change in hemoglobin (Hgb) was 2.1 g/dL (standard deviation [SD] 0.91) and average total calculated blood loss was 310 mL (SD = 154). In a multivariate regression model, computer navigation was not protective of transfusion (odds ratio [OR] 1.04, P = .73). Preoperative Hgb <10 (OR 10.5, P < .0001) and drain use (OR 2.25, P < .0001) were the most significant risk factors for transfusion. In a linear regression model, computer navigation reduced blood loss by 19 mL (SD 2.94, P < .0001) per case. CONCLUSION: In this large retrospective cohort analysis of contemporary TKA patients, computer-assisted surgery that eliminates intramedullary femoral canal instrumentation during primary TKA was not associated with reduced transfusion rates and had minimal differences in overall blood loss.

No Difference in Quality-Of-Life Outcomes in the First 7 Years Following Primary Total Knee Arthroplasty Performed Using Computer Navigation Versus Conventional Referencing: A Propensity Score-Matched Analysis.

BACKGROUND: Computer navigation techniques can potentially improve both the accuracy and precision of prosthesis implantation in total knee arthroplasty (TKA) but its impact on quality-of-life outcomes following surgery remains unestablished. METHODS: An institutional arthroplasty registry was queried to identify patients with TKA performed between January 1, 2007 and December 31, 2019. Propensity score matching based on demographical, medical, and surgical variables was used to match computer-navigated to conventionally referenced cases. The primary outcomes were Veterans RAND 12 Item Health Survey scores (VR-12 PCS and MCS), Short Form 6 Dimension utility values (SF-6D), and quality-adjusted life years (QALYs) in the first 7 years following surgery. RESULTS: A total of 629 computer-navigated TKAs were successfully matched to 1,351 conventional TKAs. The VR-12 PCS improved by a mean of 12.75 and 11.94 points in computer-navigated and conventional cases at 12-month follow-up (P = .25) and the VR-12 MCS by 6.91 and 5.93 points (P = .25), respectively. The mean VR-12 PCS improvement at 7-year follow-up (34.4% of the original matched cohort) for navigated and conventional cases was 13.00 and 12.92 points (P = .96) and for the VR-12 MCS was 4.83 and 6.30 points (P = .47), respectively. The mean improvement in the SF-6D utility score was 0.164 and 0.149 points at 12 months (P = .11) and at 7 years was 0.115 and 0.123 points (P = .69), respectively. Computer-navigated cases accumulated 0.809 QALYs in the first 7 years, compared to 0.875 QALYs in conventionally referenced cases (P = .65). There were no differences in these outcomes among a subgroup analysis of obese patients (body mass index ≥ 30 kg/m2). CONCLUSION: The use of computer navigation did not provide an incremental benefit to quality-of-life outcomes at a mean of 2.9 years following primary TKA performed for osteoarthritis when compared to conventional referencing techniques.

Imageless Computer Navigation Reduces 5-Year All-Cause Revision Rates After Primary Total Knee Arthroplasty.

BACKGROUND: The use of surgical navigation has been shown to reduce revision rates after total knee arthroplasty (TKA) in patients <65 years of age. It is unknown if this benefit extends to older patients. We hypothesized that the use of surgical navigation would reduce rates of all-cause revision in patients of all ages. METHODS: In this cohort study, we queried the Truven MarketScan all-payer database to identify patients who underwent TKA from 2007 to 2015. Current Procedural Terminology codes were used to create 2 groups based on whether intraoperative navigation was used. Demographics, comorbidities, complications, and revision rates were determined. International Classification of Diseases codes were used to determine reasons for revision. RESULTS: The conventional TKA cohort included 312,173 patients. The navigation cohort included 20,881 patients. There were not any clinically significant differences in demographics between the cohorts. All-cause revision rates were lower in the navigation cohort at 1 year (0.4% vs 0.5%, P = .04), 2 years (0.7% vs 0.9%, P = .003), and 5 years (0.9% vs 1.3%, P < .001) of follow-up. Revisions for mechanical loosening were more common in the conventional cohort (30.8% vs 21.9%, P = .009). Rates of revision for other causes, including infection, did not differ between groups, with the numbers available. CONCLUSION: The use of surgical navigation yielded a 30.7% reduction in the all-cause revision rate at 5-year follow-up compared to conventional TKA. This benefit increased as follow-up duration increased. Increased usage of this inexpensive technology, from the current 6.3% in this US cohort, may reduce healthcare costs. LEVEL OF EVIDENCE: III.

Accuracy of the trough position in expansive open-door cervical laminoplasty using computer navigation techniques: a single-centre retrospective study.

PURPOSE: This study aims to assess whether computer navigation can improve the accuracy of the trough position and clinical outcomes of expansive open-door cervical laminoplasty (EOLP). METHODS: We reviewed a single centre of 28 conventional EOLP and 24 computer navigation EOLP cases. The conventional group had 102 laminae while the navigation group had 88. The distance from the medial cortex to the pedicle on the open-door side (OD) and hinge side (HD) was measured. Furthermore, the area of the spinal canal corresponding to each lamina before and after the surgical procedure was also measured. We then compared the differences in radiographic parameters and clinical outcomes between the two groups. RESULTS: OD and HD were smaller in the navigation group compared to the conventional group, and the enlarged area of the spinal canal was larger in the navigation group than in the conventional group. The Japanese Orthopaedic Association (JOA) scores one year after the surgical procedure improved in both groups compared to the pre-operative period, and the JOA recovery rate was higher in the navigation group. The incidence of hinge fracture was lower in the navigation group, and the incidence of C5 palsy and axial pain was not statistically different between the two groups. CONCLUSION: The use of computer navigation techniques has the potential to significantly improve the accuracy of EOLP compared to conventional procedures. It has been shown to more fully expand the spinal canal and contribute to clinical efficacy.

Medial Open Wedge High tibial Osteotomy (MOWHTO) does not relevantly alter patellar kinematics: a cadaveric study.

PURPOSE: The purpose of this study was to quantify the influence of medial open wedge high tibial osteotomy on patellar kinematics using optical computer navigation, as anterior knee pain infrequently occurs postoperatively and the reason is still being unknown. METHODS: Ten medial open wedge high tibial osteotomies at supratuberosity level in 5 full body specimens were performed. The effect of the surgical procedure on patellar kinematics, measured at 5 and 10 degrees of leg alignment correction angle, was analyzed and compared to native patellar kinematics during passive motion-regarding patella shift, tilt, epicondylar distance and rotation. Linear mixed models were used for statistical analysis, a two-sided p value of ≤ 0.05 was considered statistically significant. RESULTS: Tilt behavior, medial shift and epicondylar distance did not show a significant difference regarding natural patellar kinematics at both osteotomy levels. Both osteotomy correction angles showed a significant less external rotation of the patella (p < 0.001, respectively) compared to natural kinematics. CONCLUSIONS: Except less external rotation of the patella, medial open wedge high tibial osteotomy does not seem to relevantly alter patellar alignment during passive motion. Future clinical studies have to prove the effect of MOWHTO on patellar kinematics measured in this experimental setup, especially regarding its influence on anterior knee pain.

USE OF COMPUTER NAVIGATION IN TOTAL HIP ARTHROPLASTY (LITERATURE REVIEW).

OBJECTIVE: The aim: Analyze the accuracy and ease of use of various computer navigations in total hip arthroplasty. PATIENTS AND METHODS: Materials and methods: Data from about 50 literature sources for the last two decades have been analysed. CONCLUSION: Conclusions: Analyzing the accuracy and ease of use of various computer navigations in total hip arthroplasty, we offer two the most promising for further study and improvement systems: a semi-active navigation system and augmented reality system in total hip arthroplasty.

ICD-10 Coding Mismatch in Computer and Robotic Assisted Primary Total Hip Arthroplasty.

BACKGROUND: The International Statistical Classification of Disease, 10th Revision Procedural Coding System (ICD-10-PCS) is a granular procedural classification system with the ability to precisely classify types of technology utilized in total hip arthroplasty (THA). However, coding nuances and the rapidly evolving nature of technology may lead to coding inaccuracies. The purpose of this study is to determine the accuracy of ICD-10-PCS coding in computer-navigated and robotic THA and discuss its implications on clinical data. METHODS: The arthroplasty database at a single institution was retrospectively reviewed for all primary computer and robotic assisted THAs performed between October 2015 to November 2020. The type of technology utilized was determined from the surgical record and compared with the ICD-10-PCS codes applied to each procedure. RESULTS: A total of 3721 technology-assisted THAs were identified and reviewed. 87.5% of technology-assisted THAs were coded with the correct type of technology. The most common error in computer navigated THA was the omission of the technology code, while the most common error in robotic assisted THA was the designation of codes for both computer navigation and robotic assistance. CONCLUSION: The granular nature of ICD-10-PCS allows for precise distinction between types of technology-assisted THA. However, rates of coding inaccuracy bring concern for the integrity of this data. The inaccuracy of ICD-10-PCS data is not insignificant and should bring concern for the validity of collective data sets that use it exclusively for its procedural granularity.

Handheld computer-navigated constrained total knee arthroplasty for complex extra-articular deformities.

INTRODUCTION: The present study aimed to assess the postoperative alignment and clinical outcomes of patients with complex extra-articular deformities (EADs) undergoing computer-assisted surgery (CAS) for constrained total knee arthroplasty (TKA) with modular stem extensions. MATERIALS AND METHODS: From May 2015 to July 2018, ten patients with EADs scheduled for constrained TKA were enrolled retrospectively. The preoperative average deviation from neutral (= 180°) mechanical axis was 15.3° (range of coronal alignment: 150.9° varus-202.9° valgus). Alignment was assessed using an accelerometer-based handheld CAS system. On long-leg films, the positions of the components and possible stems were analysed and templated preoperatively. The average follow-up was 3.3 years (range: 2.0-4.6 years). RESULTS: The postoperative mechanical axis was within ± 3.0° from neutral in nine patients. In all patients, the Knee Society score (KSS) and range of motion improved significantly. A constrained condylar and a rotating hinge prosthesis were used in five patients each. In eight patients, the 100-mm cementless stem that was preferred by the authors was found to be unusable for the femur or the tibia in the planning stage. For the femur, a cementless 100-mm stem was used in three, and a cemented 30-mm stem in five patients; a femoral stem was not usable in two patients. For the tibia, a cementless 100-mm stem was used in six, and a cemented 30-mm stem in two patients; a monoblock rotating hinge tibia was used in two patients. CONCLUSIONS: Complex EADs were excellently managed during constrained TKA implantation using the handheld CAS system. Templating allowed the possible stem lengths to be identified and prevented anatomical conflict with the CAS-configured mechanical alignment. Limb alignment and function improved significantly after surgery. No intra- or postoperative complications occurred. LEVEL OF EVIDENCE: Level IV, retrospective study.