The learning curve in robotic assisted knee arthroplasty is flattened by the presence of a surgeon experienced with robotic assisted surgery

Adverse events related to robotic-assisted knee arthroplasty: a cross-sectional study from the MAUDE database

BACKGROUND

Robotic-assisted surgical technique has been clinically available for decades, yet real-world adverse events (AEs) and complications associated with primary knee arthroplasty remain unclear.

METHODS

In March 2023, we searched the FDA website and extracted AEs related to robotic assisted knee arthroplasty (RAKA) from the MAUDE database over the past 10 years. The "Brand Name" function queried major robotic platforms, including active and semi-active systems. The overall incidence of AEs was estimated based on annual surgical volume from the current American Joint Replacement Registry (AJRR). Two authors independently collected data on event date, event type, device problem, and patient problem.

RESULTS

Of 839 eligible reports, device malfunction comprised mechanical failure (343/839, 40.88%) and software failure (261/839, 31.11%). For surgical complications, inappropriate bone resection (115/839, 13.71%) was most frequent, followed by bone/soft tissue damage (83/839, 9.89%). Notably, over-resection exceeding 2 mm (88/839, 10.49%), joint infection (25/839, 2.98%), and aseptic loosening (1/839, 0.12%) were major complications. Only two track pins related AEs were found. Moreover, the distribution of these AEs differed substantially between robot manufacturers. According to the AEs volume and AJRR data, the overall incidences of AEs related to RAKAs were calculated with 0.83% (839/100,892) between November 2010 and March 2023.

CONCLUSION

Our analysis shows that while reported AEs might be increasing for RAKAs, the overall rate remains relatively low. Reassuringly, device malfunction was the most commonly AEs observed, with a minor impact on postoperative outcomes. Furthermore, our data provide a benchmark for patients, surgeons, and manufacturers to evaluate RAKA performance, though continued improvement in reducing serious AEs incidence is warranted.

Analysis of the Initial Learning Curve for Robotic-Assisted Total Knee Arthroplasty Using the ROSA® Knee System

Background/Objectives: Total knee arthroplasty (TKA) is a frequent procedure in orthopedic surgery. Advances in TKA include the development of robotic-assisted systems. Training in raTKA entails a learning curve to achieve proficiency comparable to conventional manual TKA (maTKA). Methods: We conducted a prospective study of the learning curve in raTKA using the Robotic Surgical Assistant (ROSA) Knee System. The study included 180 patients (90 raTKAs; 90 maTKAs) and three surgeons (one with >15 years of experience in maTKA). The cumulative sum control chart method (CUSUM) was used to define the transition from the learning phase to the mastered phase in raTKA. Results: The learning curves were 43 cases (experienced surgeons) and 61 cases (all surgeons). Mean operative times for both phases in raTKA were longer than in maTKA (p < 0.001). In raTKA, operative times in the learning phase were longer compared to those in the mastered phase (p < 0.001). Operative times in the learning and mastered phases for all surgeons in raTKA were significantly longer compared to those in maTKA (p < 0.001); however, operative times of the experienced surgeon in the mastered phase of raTKA and in maTKA showed no differences. Conclusions: The learning curve in raTKA is dependent upon the surgeon's previous experience in maTKA.

Operating room efficiency for a high-volume surgeon in simultaneous bilateral robotic-assisted total knee arthroplasty: a prospective cohort study

Robotic-assisted total knee arthroplasty (RATKA) has been shown to achieve more accurate component positioning and target alignment than conventional jig-based instrumentation; however, concerns remain regarding its adoption since it is associated with steep learning curves, higher operational costs, and increased surgical time. This study aims to compare the operating times of three cohorts of patients undergoing simultaneous bilateral TKA, i.e., first 50 RATKA, last 50 RATKA (at the end of 1 year), and 50 conventional TKA. This prospective cohort study was conducted at a single high-volume tertiary care center by a single experienced surgeon on 150 patients (300 knees), who were allotted into three equal cohorts of 50, between February 2020 and December 2021. Simultaneous bilateral TKAs were done in all three groups and operative times recorded. We describe the technique for optimizing the surgical time of SB-RATKA for efficient operative room logistics. The operating times of the two robotic-assisted TKA cohorts were compared with the operating times of the conventional SB-TKA cohort. The mean age of the study population was 59(±6.2) years with the majority of females (82%). The mean coronal deformity was comparable between the cohorts. The mean operating time in the conventional CTKA, initial 50 RATKA, and final 50 RATKA cohorts were 115.56 (±10.7), 127.8 (±26), and 91.66 (±13.5) min, respectively, all of which showed a statistically significant difference (p < 0.001). The mean operating times of the final 50 RATKA at the end of 1 year improved by about 36 min with all the SB-RATKA cases being completed in under 120 min. The efficiency of SB-RATKA improved significantly with time and experience, resulting in shorter operational times within a year, revealing the potential of robotic-assisted surgery to surpass conventional approaches in TKA in terms of operating room efficiency.

An evaluation of factors influencing the adoption and usage of robotic surgery in lower limb arthroplasty amongst orthopaedic trainees: a clinical survey

BACKGROUND

The rise of robotics in orthopaedic training, driven by the demand for better training outcomes and patient care, presents specific challenges for junior trainees due to its novelty and steep learning curve. This paper explores how orthopaedic trainees perceive and adopt robotic-assisted lower limb arthroplasty.

METHODS

The study utilised the UTUAT model questionnaire as the primary data collection tool, employing targeted questions on a five-point Likert scale to efficiently gather responses from a large number of participants. Data analysis was conducted using partial least squares (PLS), a well-established method in previous technology acceptance research.

RESULT

The findings indicate a favourable attitude amongst trainees towards adopting robotic technology in orthopaedic training. They acknowledge the potential advantages of improved surgical precision and patient outcomes through roboticassisted procedures. Social factors, including the views of peers and mentors, notably influence trainees' decision-making. However, the availability of resources and expert mentors did not appear to have a significant impact on trainees' intention to use robotic technology.

CONCLUSION

The study contributes to the understanding of factors influencing trainees' interest in robotic surgery and emphasises the importance of creating a supportive environment for its adoption.

No Benefit of Robotic-Assisted over Computer-Assisted Surgery for Achieving Neutral Coronal Alignment in Total Knee Arthroplasty

The use of robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming increasingly popular due to better precision, potentially superior outcomes and the ability to achieve alternative alignment strategies. The most commonly used alignment strategy with RAS is a modification of mechanical alignment (MA), labeled adjusted MA (aMA). This strategy allows slight joint line obliquity of the tibial component to achieve superior balancing. In the present study, we compared coronal alignment after TKA using RAS with aMA and computer-assisted surgery (CAS) with MA that has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were compared for both techniques. In 140 patients, 68 CASs and 72 RASs, we observed no difference in postoperative measurements (median 90 degrees for all, LDFA p = 0.676, MPTA p = 0.947) and no difference in outliers <2 degrees (LDFA p = 0.540, MPTA p = 0.250). The present study demonstrates no benefit in eliminating outliers or achieving neutral alignment of both the femoral and the tibial components in robotic-assisted versus computer-assisted TKA if MA is the target. To utilize the precision of RAS, it is recommended to aim for more personalized alignment strategies. The level of evidence is level III retrospective study.

From past to digital time: Bibliometric perspective of worldwide research productivity on robotic and computer-assisted arthroplasty

Objective

The number of citations can be used as an impact marker of research work. This study aimed to determine and characterize the worldwide research productivity on robotic and computer-assisted arthroplasty.

Methods

All accessible publications from 1992 to 2023 on robotic and computer-assisted arthroplasty from Web of Science Core Collection (WOSCC) database were recorded in August 2024. The following aspects were retrieved: cited times, name of author, keywords, institution, country, year of publication, journal, title, topic, impact factor, and H-index. VOSviewer software and Microsoft Excel were conducted to make the bibliometric research visual. The nature of our study is a systematic study and was conducted in China.

Results

1061 articles were included in our study. The total cited times were 27,461 with the average number of 26. The most productive year was 2022, with a total of 158 publications. The United States contributed the highest number of articles (n = 389, 36.66%) and the Hospital for Special Surgery (n = 53, 5.00%) held the leading institution. "Orthopedics" became the dominant topic (n = 894, 84.26%) and the latest keywords "clinical outcomes", "acetabular cup placement", and "satisfaction" have mainly appeared since 2020.

Conclusions

Our analysis gives a comprehensive review of related articles on robotic and computer-assisted arthroplasty from past to future. The United States dominated studies of robotic and computer-assisted arthroplasty and a journal about arthroplasty was the most productive one. "Clinical outcomes", "Acetabular cup placement", and "Satisfaction" may become the future research hotspots.

Increased Femoral Component Flexion and No Difference in Slope in Robotic- versus Computer-Assisted Total Knee Arthroplasty When Targeting Mechanical Alignment

Robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming popular due to better precision, when compared with other instrumentation. Although RAS has been validated in comparison with computer-assisted surgery (CAS), data from clinical settings comparing these two techniques are lacking. This is especially the case for sagittal alignment. Whereas pure mechanical alignment (MA) aims for 0 to 3 degrees of flexion of the femoral component and 3° of posterior slope for the tibial component, adjusted MA (aMA) mostly used with RAS allows for flexing of the femoral component for downsizing and increase of slope for an increase of the flexion gap. In the present study, we compared sagittal alignment after TKA using RAS with aMA and CAS targeting MA, which has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Femoral component flexion and tibial slope were compared for both techniques. In 140 patients, 68 CAS and 72 RAS, we found no difference in tibial slope (p = 0.661), 1° median femoral component flexion (p = 0.023), and no difference in outliers (femur, p = 0.276, tibia, p = 0.289). RAS slightly increases femoral component flexion, but has no influence on tibial slope, when compared with CAS in TKA. If MA is the target, RAS provides no benefit over CAS for achieving the targeted sagittal alignment. LEVEL OF EVIDENCE:  Level III retrospective study.

Troubleshooting Robotics During Total Hip and Knee Arthroplasty

The introduction of new surgical technology highlights appreciable concerns; robotic arthroplasty is no exception. Acquiring comprehensive understanding of the robotic technology to avoid complications during surgery and devising troubleshooting strategies to overcome potential difficulties is of paramount importance. Troubleshooting algorithms depend on the stage of the procedure and problem encountered, such as loosening of the pins or array, registration or verification problems, or malfunctioning of the device, which is rare. This article aims to outline reproducible workflows and solutions for troubleshooting during robotic-arm assisted total hip arthroplasty and total knee arthroplasty.

Image-based robotic-arm assisted unicompartmental knee arthroplasty provides high survival and good-to-excellent clinical outcomes at minimum 10 years follow-up

PURPOSE

The purpose of the present study was to determine the incidence of revision and report on clinical outcomes at a minimum of 10 years follow-up in patients who had received a medial unicompartmental knee arthroplasty (UKA) with an three-dimensional image-based robotic system.

METHODS

A total of 239 patients (247 knees), who underwent medial robotic-arm assisted (RA)-UKA at a single center between April 2011 and June 2013, were assessed. The mean age at surgery was 67.0 years (SD 8.4). Post-operatively, patients were administered the Forgotten Joint Score-12 (FJS-12) and asked about their satisfaction (from 1 to 5). Post-operative complications were recorded. Failure mechanisms, revisions and reoperations were collected. Kaplan-Meier survival curves were calculated, considering revision as the event of interest.

RESULTS

A total of 188 patients (196 knees) were assessed at a mean follow-up of 11.1 years (SD 0.5, range 10.0-11.9), resulting in a 79.4% follow-up rate. Seven RA-UKA underwent revision, resulting in a survivorship rate of 96.4% (CI 94.6%-99.2%). Causes of revision included aseptic loosening (2 cases), infection (1 case), post-traumatic (1 case), and unexplained pain (3 cases). The mean FJS-12 and satisfaction were 82.2 (SD 23.9) and 4.4 (SD 0.9), respectively. Majority of cases (174/196, 88.8%) attained the Patient Acceptable Symptoms State (PASS, FJS-12 > 40.63). Male subjects had a higher probability of attaining a "forgotten joint" (p < 0.001) and high satisfaction (equal to 5, p < 0.05), when compared to females.

CONCLUSIONS

Three-dimensional image-based RA-UKA demonstrated high implant survivorship and good-to-excellent clinical outcomes at minimum 10 years follow-up. Pain of unknown origin represented the most common reason for RA-UKA revision.

LEVEL OF EVIDENCE

III.

Learning curve for imageless robotic-assisted total knee arthroplasty in non-fellowship trained joint replacement surgeons

Introduction

Robotic-assisted total knee arthroplasty (RA-TKA) has become increasingly popular, although an associated learning curve can be a deterrent for some surgeons. Prior studies have addressed this learning curve in fellowship-trained arthroplasty surgeons, however the learning curve among non-fellowship-trained surgeons remains unclear. The objective of this study was to investigate the learning curve for imageless RA-TKA related to operative time and rates of complications among two non-arthroplasty-trained orthopedic surgeons.

Methods

This retrospective case series included 200 RA-TKA consecutive cases performed by two non-arthroplasty-trained orthopedic surgeons (100 each). Cases were divided into 2 cohorts for each surgeon: the first 50 consecutive cases and the second 50 cases. These cohorts were then compared to assess for trends in each surgeon as well as in both surgeons combined. Mean operative times were compared, as were hospital length of stay, complications, readmission, and reoperations.

Results

For both surgeons, the mean operative time significantly decreased from the first 50 cases to the next 50 cases (116.5 vs 108.4 min for surgeon 1, P = 0.031; 125.7 vs 109.1 min for surgeon 2, P = 0.001). No significant differences were found among length of stay, complications, readmissions, or reoperations between cohorts.

Conclusion

General orthopedic surgeons can expect to optimize operative time within 50 cases, while not carrying associated risks of related complications during the early learning period.

Image-free handheld robotic-assisted technology improved the accuracy of implant positioning compared to conventional instrumentation in patients undergoing simultaneous bilateral total knee arthroplasty, without additional benefits in improvement of clinical outcomes

PURPOSE

The purpose of this study was to compare the clinical and radiological outcomes in patients who underwent simultaneous bilateral total knee arthroplasty (SB-TKA) using either robotic-assisted TKA (RA-TKA) or conventional TKA (C-TKA).

METHODS

Included were the patients who underwent SB-TKA between January 2018 and January 2020 and had a minimum follow-up of 2 years. Of 151 patients included, 117 patients were operated using an image-free handheld robotic sculpting system (RA-TKA group) and 34 patients operated using conventional instrumentation (C-TKA group). The key outcomes noted were multiple patient-reported outcomes (PROs), adverse events, and radiological outcomes. Two investigators independently measured the radiological outcomes on pre- and post-operative radiographs in coronal plane (medial proximal tibial angle [MPTA] and anatomic lateral distal femoral angle [aLDFA]) and sagittal plane (posterior tibial slope [PTS] and posterior condylar offset [PCO]). The chi-square test was used to examine categorical variables. Student's t test was used to analyze the continuous variables.

RESULTS

Patients in both groups were similar in baseline characteristics (gender, body mass index, incidence of comorbidities, and length of hospital stay) except that RA-TKA group patients younger (66.7 ± 8.9 vs 70.4 ± 10.5, P = 0.037) than C-TKA group. The operative time was longer in RA-TKA group as compared to C-TKA (189.3 ± 37.1 vs 175.0 ± 28.2, P = 0.040). The final PROs at each were similar between the two groups (P > 0.05). The values of PROs at final follow-up in RA-TKA compared to C-TKA were VAS pain (0.4 ± 0.9 vs 0.4 ± 0.5), KOOS-JR (89.3 ± 5.8 vs 87.1 ± 5.3), and physical (55.9 ± 2.8 vs 55.4 ± 3.2), mental (61.1 ± 4.4 vs 60.2 ± 4.7) component of VR-12 scores, and KSS satisfaction (37.5 ± 1.1 vs 37.1 ± 2.2) (all P > 0.50 or non-significant [n.s.]). While one patient in RA-TKA required revision of femoral component for peri-prosthetic fracture, none of the patient in conventional group were revised (0.85% vs 0%, P = n.s.). The proportion of patients with outliers in RA-TKA group was lower for aLDFA (2.6% vs 22.1%, P < 0.01) and PTS (0% vs 35%, P < 0.01).

CONCLUSION

This comparative study in patients undergoing SB-TKA found reduction of outliers in femoral and tibial implant positioning with RA-TKA as compared to C-TKA. There were no differences in both groups for pain, function, and satisfaction at a minimum of 2 years of follow-up.

LEVEL OF EVIDENCE

III Therapeutic Study.

NAVIO RATKA shows similar rates of hemoglobin-drop, adverse events, readmission and early revision vs conventional TKA: a single centre retrospective cohort study

PURPOSE

Despite widespread adoption of NAVIO robotic-assisted total knee arthroplasty (NAVIO RATKA) in clinical practice, clinical outcome in terms of adverse events and complications remains unclear. The purpose of this study was to compare adverse events, length of stay, surgical time, hemoglobin drop, early readmission rate and revision rate between conventional TKA (CTKA) and NAVIO RATKA.

METHODS

This single-centre retrospective cohort analysis compared 230 NAVIO RATKA patients to 489 CTKA patients with a minimal follow-up of 12 months. Baseline demographic and comorbidity parameters were collected, as well as length of stay, revision rate and reason for revision, early readmission rate (< 6w) and reason for readmission, post-operative hemoglobin levels, adverse events, surgical time and operating room time. Data were compared using Mann-Whitney U test for continuous data without normal distribution and ordinal data, categorical variables were compared using the Chi-square or Fisher exact test.

RESULTS

There were no clinically relevant baseline demographic or comorbidity differences between groups. CTKA had shorter length of stay than NAVIO RATKA (5.0 days vs 5.4 days, p = 0.010) but trended towards a higher reoperation rate (4.1% vs 1.7%, p = .144, n.s). No differences were found in hemoglobin drop, readmission rate or overall incidence of adverse events, but CTKA showed more hematoma formation (1.6% vs 0%, p = .044) and higher incidence of periprosthetic joint infection (PJI) (1% vs 0%, p = n.s.), whilst NAVIO RATKA showed more periprosthetic fractures and persistent wound drainage (0.4% vs 2.2%, p = .038 and 0.6% vs 4.3%, p = .001, respectively). Surgical time remained significantly longer in NAVIO RATKA during all 230 cases (87 min vs 67.6 min) and showed a continuous downward trend.

CONCLUSIONS

This study further validates the usage of NAVIO RATKA as a safe method to perform TKA, with comparable short term outcomes to CTKA in terms of early revisions and adverse events. Surgeons should be mindful of the differing adverse event profile in NAVIO RATKA and adjust their patient selection accordingly to ensure optimal outcomes. In addition, surgeons using NAVIO RATKA should expect a linear learning curve and a surgical time exceeding that of CTKA.

LEVEL OF EVIDENCE

Level III (therapeutic retrospective cohort study).

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

PURPOSE

The purpose of this study was to compare the precision of bony resections during total knee arthroplasty (TKA) performed using different computer-assisted technologies.

METHODS

Patients who underwent a primary TKA using an imageless accelerometer-based handheld navigation system (KneeAlign2®, OrthAlign Inc.) or computed tomography-based large-console surgical robot (Mako®, Stryker Corp.) from 2017 to 2020 were retrospectively reviewed. Templated alignment targets and demographic data were collected. Coronal plane alignment of the femoral and tibial components and tibial slope were measured on postoperative radiographs. Patients with excessive flexion or rotation preventing accurate measurement were excluded.

RESULTS

A total of 240 patients who underwent TKA using either a handheld (n = 120) or robotic (n = 120) system were included. There were no statistically significant differences in age, sex, and BMI between groups. A small but statistically significant difference in the precision of the distal femoral resection was observed between the handheld and robotic cohorts (1.5° vs. 1.1° difference between templated and measured alignments, p = 0.024), though this is likely clinically insignificant. There were no significant differences in the precision of the tibial resection between the handheld and robotic groups (coronal plane 0.9° vs. 1.0°, n.s.; sagittal plane 1.2° vs. 1.1°, n.s.). There were no significant differences in the rate of overall precision between cohorts (n.s.).

CONCLUSIONS

A high degree of component alignment precision was observed for both imageless handheld navigation and CT-based robotic cohorts. Surgeons considering options for computer-assisted TKA should take other important factors, including surgical principles, templating software, ligament balancing, intraoperative adjustability, equipment logistics, and cost, into account.

LEVEL OF EVIDENCE

III.

Learning curve for robot-assisted knee arthroplasty; optimizing the learning curve to improve efficiency

The introduction of robot-assisted (RA) systems in knee arthroplasty has challenged surgeons to adopt the new technology in their customized surgical techniques, learn system controls, and adjust to automated processes. Despite the potential advantages of RA knee arthroplasty, some surgeons remain hesitant to adopt this novel technology owing to concerns regarding the cumbersome adaptation process. This narrative review addresses the learning-curve issues in RA knee arthroplasty based on the existing literature. Learning curves exist in terms of the operative time and stress level of the surgical team but not in the final implant positions. The factors that reduce the learning curve are previous experience with computer-assisted surgery (including robot or navigation systems), specialization in knee surgery, high volume of knee arthroplasty, optimization of the RA workflow, sequential implementation of RA surgery, and consistency of the surgical team. Worse clinical outcomes may occur in the early postoperative period, but not in the later period, in RA knee arthroplasty performed during the learning phase. No significant differences were observed in implant survival or complication rates between the RA knee arthroplasties performed during the learning and proficiency phases.

Explanatory and pragmatic trials in orthopaedics - Have we done the right studies?

Recent decades have seen marked advances in the quality of clinical orthopaedic trauma research, and with this has come a rise in the number of randomised clinical trials (RCTs) being conducted in orthopaedic trauma. These trials have been largely valuable in driving evidence-based management of injuries which previously had clinical equipoise. However, though RCTs are traditionally seen as the 'gold standard' of high-quality research, this research method is comprised primarily of two entities, explanatory and pragmatic designs, each with its own strengths and limitations. Most orthopaedic trials lie within a continuum between these designs, with varying degrees of both pragmatic and explanatory features. In this narrative review we provide a summary of the nuances within orthopaedic trial design, the advantages and limitations of such designs, and suggest tools which may aid clinicians in the appropriate selection and evaluation of trial designs.

Postoperative full leg radiographs exhibit less residual coronal varus deformity compared to intraoperative measurements in robotic arm-assisted total knee arthroplasty with the MAKO™ system

PURPOSE

Robotic arm-assisted total knee arthroplasty (raTKA), currently a major trend in knee arthroplasty, aims to improve the accuracy of implant positioning and limb alignment. However, it is unclear whether and to what extent manual radiographic and navigation measurements with the MAKO™ system correlate. Nonetheless, a high agreement would be crucial to reliably achieve the desired limb alignment.

METHODS

Thirty-six consecutive patients with osteoarthritis and a slight-to-moderate varus deformity undergoing raTKA were prospectively included in this study. Prior to surgery and at follow-up, a full leg radiograph (FLR) under weight-bearing conditions was performed. In addition, a computed tomography (CT) scan was conducted for preoperative planning. The hip-knee-ankle angle (HKA), mechanical lateral distal femur angle (mLDFA), mechanical medial proximal tibial angle (mMPTA) and joint line convergence angle (JLCA) were measured in the preoperative and follow-up FLR as well as in the CT scout (without weight-bearing) by three independent raters. Furthermore, the HKA was intraoperatively assessed with the MAKO™ system before and after raTKA.

RESULTS

Significantly higher HKA values were identified for intraoperative deformity assessment using the MAKO system compared to the preoperative FLR and CT scouts (p = 0.006; p = 0.05). Intraoperative assessment of the HKA with final implants showed a mean residual varus deformity of 3.2° ± 1.9°, whereas a significantly lower residual varus deformity of 1.4° ± 1.9° was identified in the postoperative FLR (p < 0.001). The mMPTA was significantly higher in the preoperative FLR than in the CT scouts (p < 0.001). Intraoperatively, the mMPTA was adjusted to a mean of 87.5° ± 0.9° with final implants, while significantly higher values were measured in postoperative FLRs (p < 0.001). Concerning the mLDFA, no significant differences could be identified.

CONCLUSION

The clinical importance of this study lies in the finding that there is a difference between residual varus deformity measured intraoperatively with the MAKO™ system and those measured in postoperative FLRs. This has implications for preoperative planning as well as intraoperative fine-tuning of the implant position during raTKA to avoid overcorrection of knees with slight-to-moderate varus osteoarthritis.

LEVEL OF EVIDENCE

Level IV.

Trends in Computer-Assisted Surgery for Total Knee Arthroplasty in Germany: An Analysis Based on the Operative Procedure Classification System between 2010 to 2021

Alignment strategies for primary total knee arthroplasty (TKA) have changed significantly over time with a shift towards a more individualized alignment goal. At the same time, computer-assisted surgery (CAS) has gained interest for intraoperative control and accuracy in implant positioning and limb alignment. Despite the often discussed benefits and drawbacks of robotics and navigation for TKA, the routine use of these new devices on a day-to-day basis remains obscure. Therefore, nationwide hospital billing data based on the Operation Procedure Classification System (OPS) were retrieved from the Federal Statistical Office of Germany for the period from 2010 to 2021. OPS codes for primary total knee arthroplasty (OPS code: 5-822*) were further analyzed regarding the usage of computer navigation (additional OPS code: 5-988) or robotic devices (additional OPS code: 5-987). Gender and age at the time of surgery were also assessed. The results show a total of 2,226,559 primary TKAs were implanted between 2010 and 2021, of which 2,044,914 were performed conventionally (91.84% of all TKAs). A total of 170,276 TKAs were performed using navigation technique (7.65% of all TKAs) and another 11,369 TKAs were performed using robotics (0.51% of all TKAs). For the period from 2018 to 2021, a substantial increase in robot-assisted TKA (R-TKA) was observed, with an average increase rate of 84.74% per year, while the number of navigated TKAs declined (-3.67% per year). Computer-assisted surgery, and particularly robotics for TKA, are seeing growing popularity and stepwise translation into routine clinical use in Germany, with a steep increase rate of more than 80% per year since 2018. Nevertheless, the majority of TKAs are still performed using manual instrumentation, rendering conventional TKA the currently unchanged gold standard.