Robot-assisted total hip arthroplasty

The LANCET robotic system can improve surgical efficiency in total hip arthroplasty: A prospective randomized, multicenter, parallel-controlled clinical trial

Objective

To evaluate the accuracy and safety of the LANCET robotic system, a robot arm assisted operation system for total hip arthroplasty via a multicenter clinical randomized controlled trial.

Methods

A total of 116 patients were randomized into two groups: LANCET robotic arm assisted THA group (N = 58) and the conventional THA group (N = 58). General information about the patients was collected preoperatively. Operational time and bleeding were recorded during the surgery. The position of the acetabular prosthesis was evaluated by radiographs one week after surgery and compared with preoperative planning. Harris score, hip mobility, prosthesis position and angle and complications were compared between the two groups at three months postoperatively.

Results

None of the 111 patients who ultimately completed the 3-month follow-up experienced adverse events such as hip dislocation and infection during follow-up. In the RAA group, 52 (92.9 %) patients were located in the Lewinnek safe zone and 49 (87.5 %) patients were located in the Callanan safe zone. In the control group were 47 (85.5 %) and 44 (80.0 %) patients, respectively. In the RAA group, 53 (94.6 %) patients had a postoperative acetabular inclination angle and 51 (91.1 %) patients had an acetabular version angle within a deviation of 5° from the preoperative plan. These numbers were significantly higher than those of the control group, which consisted of 42 (76.4 %) and 34 (61.8 %) patients respectively. There were no significant differences between the two groups of subjects in terms of general condition, intraoperative bleeding, hip mobility, and adverse complications.

Conclusion

The results of this prospective randomized, multicenter, parallel-controlled clinical study demonstrated that the LANCET robotic system leads conventional THA surgery in accuracy of acetabular cup placement and does not differ from conventional THA surgery in terms of postoperative hip functional recovery and complications.

The translational potential of this article

In the past, the success rate of total hip arthroplasty (THA) relied heavily on the surgeon's experience. As a result, junior doctors needed extensive training to become proficient in this technique. However, the introduction of surgical robots has significantly improved this situation. By utilizing robotic assistance, both junior and senior doctors can perform THA quickly and efficiently. This advancement is crucial for the widespread adoption of THA, as patients can now receive surgical treatment in local facilities instead of overwhelming larger hospitals and straining medical resources. Moreover, the development of surgical robots with fully independent intellectual property rights holds immense value in overcoming the limitations of high-end medical equipment. This aligns with the objectives outlined in the 14th Five Year Plan for National Science and Technology Strategy.

Fostering Excellence in Knee Arthroplasty: Developing Optimal Patient Care Pathways and Inspiring Knowledge Transfer of Advanced Surgical Techniques

Osteoarthritis of the knee is common. Early sports trauma or cartilage defects are risk factors for osteoarthritis. If conservative treatment fails, partial or total joint replacement is often performed. A joint replacement aims to restore physiological biomechanics and the quality of life of affected patients. Total knee arthroplasty is one of the most performed surgeries in musculoskeletal medicine. Several developments have taken place over the last decades that have truly altered the way we look at knee arthroplasty today. Some of the fascinating aspects will be presented and discussed in the present narrative review.

Fluoroscopy-guided direct anterior approach total hip arthroplasty provides more accurate component positions in the supine position than in the lateral position

PURPOSE

The position of the acetabular and femoral components is critical for stability and wear resistance. The aim of this study is to investigate whether the fluoroscopy-guided direct anterior approach in the supine position (S-DAA) is more helpful in improving the position of acetabular and femoral components than the fluoroscopy-guided direct anterior approach in the lateral decubitus position (L-DAA).

METHODS

A retrospective analysis of 76 cases of fluoroscopy-guided direct anterior approach total hip arthroplasty (38 cases in the S-DAA and 38 cases in the L-DAA group) was performed in one hospital from 2019 to 2021. The differences in inclination, anteversion, femoral offset (FO), global offset (GO), and leg length discrepancy (LLD) measurements during and after surgery were analyzed. The postoperative femoral offset (FO), global offset (GO), leg length discrepancy (LLD), and preoperative and postoperative Harris hip score were compared between the two groups.

RESULTS

In the S-DAA group, there were no significant differences in the mean intraoperative inclination angle anteversion angle, FO, GO, and LLD compared to the postoperative values, whereas in the L-DAA group, there were significant differences between the intraoperative and postoperative measurements (P < 0.001, P = 0.009, P＜0.001, P＜0.001 and P = 0.008, respectively). Additionally, there were significant differences in the accuracy of LLD, FO, and GO between the two groups (P < 0.001). Compared with the L-DAA group, the average differences of inclination, anteversion, LLD, FO, and GO during and after operation in the S-DAA group were smaller, and the consistency was higher. There was a significant difference in Harris hip score between the two groups at 1 week after surgery (P = 0.033). There was no significant difference in Harris hip score between 1 month and 3 months after surgery (P = 0.482 and P = 0.797, respectively).

CONCLUSIONS

In the supine group, the direct anterior approach (DAA) provides more accurate positioning of the acetabular and femoral components. However, there was no significant difference in hip joint function and activity between the two groups at follow-up.

Fluoroscopy-based robotics in total hip arthroplasty mitigates laterality-based differences in acetabular cup placement when compared to the manual, fluoroscopic- assisted technique

BACKGROUND

Robotic assistance in total hip arthroplasty (RA-THA) has been shown to minimize laterality-based differences in acetabular cup positioning.

OBJECTIVE

To determine if the use of a novel, fluoroscopy-based RA-THA system mitigates differences in acetabular cup placement between left (L) and right (R) side hip procedures, when compared to manual, fluoroscopic-assisted technique.

METHODS

We conducted a retrospective review of 106 consecutive mTHA (40 L/66 R) and 102 RA-THA (48 L/54 R) primary direct anterior approach procedures. All cases were performed by a single right-hand-dominant surgeon, for a pre-operative diagnosis of osteoarthritis, avascular necrosis, or rheumatoid arthritis. Outcomes included acetabular cup inclination and anteversion, and the proportion of cups within the Lewinnek safe-zone.

RESULTS

The average inclination of mTHA L cases was smaller than that of mTHA R cases (41.10∘± 7.38 vs. 43.97∘± 6.27; p= 0.04). For RA-THA, L and R cup angles were similar. There were fewer overall mTHA hips within the Lewinnek safe-zone compared to RA-THA (0.59 vs. 0.78; p= 0.003), as well as fewer mTHA R cases than RA-THA R cases (0.59 vs. 0.80; p= 0.03) within safe zone.

CONCLUSION

Use of a novel, fluoroscopy-based robotic system mitigates laterality-based differences in acetabular cup placement that were observed in a manual, fluoroscopic-assisted cohort.

Accuracy and safety of a new robotic arm for both femoral and acetabular side in total hip arthroplasty: a cadaveric study

BACKGROUND

To investigate the accuracy and safety of a newly constructed robotic arm which can cover the whole process of THA, we performed a series of robot-assisted total hip replacement on the cadaver.

METHODS

Fifteen frozen cadaveric specimens (30 hips) were used for this study. In this investigation, united hip system and Longwell robotic-assisted system were used. The entire lower limb was CT scanned prior to surgery. The 3D model was produced based on CT data; the site of the prosthesis, including acetabular anteversion, inclination angle, and the position of femoral prosthesis, was planned. With the assistance of a robotic arm, the surgeon changed the parameters based on the preoperative plan and the actual condition during surgery, and completed the whole procedure. Following surgery, we measured the acetabular anteversion angle, acetabular inclination angle, femur anteversion angle, combined anteversion angle, stem angulation, and canal fill ratio.

RESULTS

The parameters proved that the acetabular anteversion angle was 16.85 ± 3.00°, the acetabular inclination angle was 40.38 ± 5.37°, femur anteversion angle was 15.90 ± 9.01°, combined anteversion angle was 32.75 ± 9.03°, stem angulation was 1.84 ± 0.99°, and leg length discrepancy was 2.47 ± 1.43 mm. The canal fill ratio (CFR) of femoral prosthesis of osteotomy line in sagittal section is 99.72 ± 1.54% and in coronal section is 62.94 ± 8.91%; below osteotomy line 2.5 cm in sagittal section is 100.00% and in coronal section is 81.48 ± 12.94%; below osteotomy line 7.5 cm in sagittal section is 59.51 ± 12.94% and in coronal section is 89.79 ± 11.13%; femoral shaft isthmus in sagittal section is 56.41 ± 13.80% and in coronal section is 84.95 ± 15.17%.

CONCLUSION

The accuracy and safety of this novel robotic arm are suitable for preparing both the acetabular and femoral sides, providing evidence for clinical trial.

A novel algorithm to efficiently calculate the impingement-free range of motion of irregularly-shaped total hip arthroplasty components

There is great difficulty in quickly calculating the impingement-free range of motion (IFROM) of hip components with complex shapes after total hip arthroplasty. We have established a new algorithm to investigate the effect of different shapes of hip components on the IFROM and impingement-free safe zone (IFSZ). Then find the best combination of hip prosthesis and the optimal mounting position of the elevated-rim liner under different radiographic anteversion (RA) and radiographic inclination (RI) of the cup. We found the larger the opening angle of the beveled-rim liner and the smaller the cross-sectional area of the stem neck with an inverted teardrop cross-sectional shape, the greater the IFROM of the hip component. The beveled-rim liner in combination with the stem neck with an inverted teardrop-shaped cross-section could provide the greatest IFSZ (excluding the flat-rim liner). The optimal orientation of the elevated-rim liner was the posterior-inferior side (RI ≤ 37°), posterior-superior side (RI ≥ 45°), and posterior side (37° ≤ RI ≤ 45°). Our novel algorithm provides a solution to analyze the IFROM of any hip prosthesis with any complex shape. The shape and size of the cross-section of the stem neck, the orientation of the elevated rim, and the shape and opening angle of the liner are all critical factors for the quantitative calculation of the IFROM and mounting safe zone of the prosthesis. Stem necks with inverted teardrop cross-section and beveled-rim liner improved the IFSZ. The optimal direction of the elevated rim is not constant but varies with RI and RA.

The landscape of surgical robotics in orthopedics surgery

Orthopedic surgery is one of the first surgical specialties to apply surgical robotics in clinical practice, which has become an interesting field over the years with promising results. Surgical robotics can facilitate total joint arthroplasty by providing robotic support to accurately prepare the bone, improving the ability to reproduce alignment, and restoring normal kinematics. Various robotic systems are available on the market, each tailored to specific types of surgeries and characterized by a series of features with different requirements and/or modus operandi. Here, a narrative review of the current state of surgical robotic systems for total joint knee arthroplasty is presented, covering the different categories of robots, which are classified based on the operation, requirements, and level of interaction with the surgeon. The different robotic systems include closed/open platform, image-based/imageless, and passive/active/semi-active systems. The main goal of a robotic system is to increase the accuracy and precision of the operation regardless of the type of system. Despite the short history of surgical robots, they have shown clinical effectiveness compared to conventional techniques in orthopedic surgery. When considering which robotic system to use, surgeons should carefully evaluate the different benefits and drawbacks to select the surgical robot that fits their needs the best.

Is robotic assistance more eye-catching than computer navigation in joint arthroplasty? A Google trends analysis from the point of public interest

Computer-assisted navigation system (CAS) and robotic assisted surgery (RAS) have been widely used in joint arthroplasty, but few studies focused on public interest. We aimed to evaluate current trend and seasonality of public interest in CAS and RAS arthroplasty over the past 10 years, and forecast the future development. All data related to CAS or RAS arthroplasty from January 2012 to December 2021 were collected through Google Trends. Public interest was described by relative search volume (RSV). Pre-existing trend was evaluated by linear and exponential models. Time series analysis and ARIMA model were utilized to analyze the seasonality and future trend. R software 3.5.0 was for statistics analysis. Public interest in RAS arthroplasty has been continuously increasing (P < 0.001) and exponential model (R2 = 0.83, MAE = 7.35, MAPE = 34%, RSME = 9.58) fitted better than linear one (R2 = 0.78, MAE = 8.44, MAPE = 42%, RSME = 10.67). CAS arthroplasty showed a downtrend (P < 0.01) with equivalent R2 (0.04) and accuracy measures (MAE = 3.92, MAPE = 31%, RSME = 4.95). The greatest popularity of RAS was observed in July and October, while the lowest was in March and December. For CAS, a rise of public interest was in May and October, but lower values were observed in January and November. Based on ARIMA models, the popularity of RAS might continuously increase and nearly double in 2030, along with a stability with slight downtrend for CAS. Public interest in RAS arthroplasty has been continuously increasing and seems to maintain this uptrend in the next 10 years, whereas popularity of CAS arthroplasty will likely remain stable.

Preliminary study of short-term outcomes and learning curves of robotic-assisted THA: comparison between closed platform robotic system and open platform robotic system

BACKGROUND

Both closed platform and open platform robotic-assisted total hip arthroplasty (THA) have recently been recommended as a viable treatment option for achieving accurate positioning of components. Yet, limited studies paid attention to the differences between the closed platform robotic system and the open platform robotic system. Hence, this study aimed to investigate clinical outcomes, radiographic outcomes, complication rates and learning curve of two systems.

MATERIALS AND METHODS

We retrospectively included 62 patients (31 closed robotic system and 31 open robotic system) who underwent THA between February 2021 and January 2023. The demographics, operating time, cup positioning, complications and hip Harris score were evaluated. Learning curves of operation time was conducted using cumulative sum (CUSUM) analysis.

RESULTS

There were no differences in surgical time (76.7 ± 12.1 min vs. 72.3 ± 14.8 min), estimated blood loss (223.2 ± 13.2 ml vs. 216.9 ± 17 ml) and Harris Hip score (HHS) between closed platform robotic system and the open platform robotic system. The closed robotic system and the open robotic system were associated with a learning curve of 9 cases and 7 cases for surgical time respectively, based on the satisfying rate of Lewinnek's safe zone outliers (1/31, 96.8%) and no occurrence of complication. Both robotic systems had significant reduction in overall surgical time, the duration of acetabulum registration, and estimated blood loss between learning phase and proficiency phase.

CONCLUSION

The authors suggest that the surgical outcomes and safe zone outlier rate of the open robotic-assisted THA were similar to those of the closed robotic-assisted THA. These two robotic-assisted are associated with comparable learning curves and both have the precise positioning of acetabular component. From learning phase to proficiency phase, the rate of positions within the safe zone differed only marginally (88.9-100% vs. 85.7-100%) based on a rather low number of patients. This is not a statistically significant difference. Therefore, we suggest that THA undergoing with the robotic-assisted system is the relatively useful way to achieve planned acetabular cup position so far.

Does robot-assisted surgery reduce leg length discrepancy in total hip replacement? Robot-assisted posterior approach versus direct anterior approach and manual posterior approach: a propensity score-matching study

BACKGROUND

Advocates of robot-assisted technique argue that robots could improve leg length restoration in total hip replacement. However, there were few studies to compare the robot-assisted posterior approach (RPA) with conventional posterior approach (PA) THA and direct anterior approach (DAA) THA in LLD. This study aimed to determine whether robot-assisted techniques could significantly reduce LLD compared to manual DAA and manual PA.

METHODS

We retrospectively reviewed the cohort of consecutive ONFH patients who underwent THA robot-assisted posterior, manual posterior, and manual DAA from January 2018 to December 2020 in one institution. One experienced surgeon performed all procedures. We calculated the propensity score to match similar patients in different groups by multivariate logistic regression analysis for each patient. We included confounders consisting of age at the time of surgery, sex, body mass index (BMI), and preoperative LLD. Postoperative LLD and Harris hip scores (HHS) at two years after surgery of different cohorts were compared.

RESULT

We analyzed 267 ONFH patients treated with RPA, DAA, or PA (73 RPA patients, 99 DAA patients, and 95 PA patients). After propensity score matching, we generated cohorts of 40 patients in DAA and RPA groups. And we found no significant difference in postoperative LLD between RPA and DAA cohorts (4.10 ± 3.50 mm vs 4.60 ± 4.14 mm, p = 0.577) in this study. The HHS at 2 years postoperatively were 87.04 ± 7.06 vs 85.33 ± 8.34 p = 0.202. After propensity score matching, we generated cohorts of 58 patients in manual PA and RPA groups. And there were significant differences in postoperative LLD between the RPA and PA cohorts. (3.98 ± 3.27 mm vs 5.38 ± 3.68 mm, p = 0.031). The HHS at 2 years postoperatively were 89.38 ± 6.81 vs 85.33 ± 8.81 p = 0.019. After propensity score matching, we generated cohorts of 75 patients in manual DAA and PA groups. And there were significant differences in postoperative LLD between the DAA and PA cohorts. (4.03 ± 3.93 mm vs 5.39 ± 3.83 mm, p = 0.031) The HHS at 2 years postoperatively were 89.71 ± 6.18 vs 86.91 ± 7.20 p = 0.012.

CONCLUSION

This study found no significant difference in postoperative LLD between RPA and DAA, but we found a significant difference between RPA and manual PA, DAA and manual PA in ONFH patients. We found a significant advantage in leg length restoration in primary total hip arthroplasty with robot-assisted surgery.

Precise acetabular positioning, discrepancy in leg length, and hip offset using a new seven-axis robot-assisted total hip arthroplasty system requires no learning curve: a retrospective study

Objective

The purpose of the present study was to determine the learning curve for a novel seven-axis robot-assisted total hip arthroplasty (RA-THA) system, and to explore whether it was able to provide greater accuracy in acetabular cup positioning, superior leg length discrepancy (LLD), and hip offset than conventional methods.

Methods

A total of 160 patients in which unilateral THA was performed in the second affiliated Hospital of Xi'an Jiaotong University from July 2021 to September 2022 were studied. The first 80 patients underwent robot-assisted THA, while conventional THA was performed on the subsequent 80 by the same team of experienced surgeons. The learning curve for the RA-THA system was evaluated using cumulative sum (CUSUM) analysis. The demographic data, preoperative clinical data, duration of surgery, postoperative Harris hip score (HHS) and postoperative radiographic data from patients that had conventional THA were compared.

Results

The 80 patients who underwent primary unilateral RA-THA comprised 42 males and 38 females and were followed up for 12 weeks. Using analysis by CUSUM, the learning curve of the RA-THA system could be divided into learning and proficiency phases, the former of which consisted of the first 17 cases. There was no significant difference between the learning and proficiency phases in terms of LLD, hip offset, or accuracy of acetabular prosthesis position in the RA-THA groups. The proportion of acetabular prostheses located in the Lewinnek safe zone was 90.5% in the proficiency group and 77.5% in the conventional group, respectively, a difference that was statistically significant (P < 0.05). The absolute error between target angle and postoperative measured angle of anteversion was statistically significant in the proficiency group and the conventional group((P < 0.05). Postoperative acetabular anteversion and LLD were 19.96 ± 5.68° and 6.00 (5.00) mm in the proficiency group, respectively, and 17.84 ± 6.81° and 8.09 (4.33) mm using conventional surgery, respectively (anteversion: P = 0.049; LLD: P < 0.001).

Conclusions

The surgical team required a learning curve of 17 cases using the RA-THA system to become proficient. There was no learning curve for other parameters, namely LLD, hip offset, or accuracy of acetabular prosthesis positioning. During the proficiency phase, the RA system was superior to conventional THA for control of leg length and accuracy of acetabular cup placement.

Consideration of pelvic tilt at the time of preoperative planning improves standing acetabular position after robotic-arm assisted total hip arthroplasty

INTRODUCTION

Approximately half of dislocating total hip arthroplasties (THAs) demonstrate acetabular component position within traditional safe zones. It is unclear if postoperative functional acetabular position can be reliably improved by considering preoperative pelvic tilt. We investigated whether standing cup position targets could be more accurately achieved by considering preoperative standing pelvic tilt in addition to bone landmarks when planning for robot-assisted THA.

METHODS

We reviewed 146 THAs performed by a single surgeon using computed tomography-based 3-dimensional planning and robotic technology to guide acetabular reaming and component insertion. Planning for 73 consecutive cases started at 40° of inclination and 22° of anteversion relative to the supine functional plane and was adjusted to better match native hip anatomy. Planning for the next 73 cases was modified to consider standing pelvic position based on standing preoperative radiographs. We compared groups to determine the rate when cups were placed outside our standing targets of 15-30° anteversion and 35-50° inclination.

RESULTS

Cup position proved to be reliable in both groups, with 83% of cups in the anatomic planning cohort and 90% of cups in the functional planning cohort achieving standing targets for both anteversion and inclination (p = 0.227). Variances were lower in the functional planning group: 9.4° versus 15.8° of inclination (p = 0.079) and 18.3° versus 26.1° of anteversion (p = 0.352). The range of functional positions was narrower in the functional planning group: 35.7-47.5° versus 31.8-54.9° of inclination and 16.7-35.0° versus 10.1-35.9° of anteversion.

DISCUSSION

Our results suggest enhanced planning that considers pelvic tilt, when coupled to a precision tool to achieve the plan, can reliably achieve target standing component positions. Considering preoperative functional pelvic position may improve postoperative functional acetabular component placement in THA, but the clinical benefit of this has yet to be confirmed.

The Accuracy of Computed Tomography-Based, Three-Dimensional Implant Planning in Robotic-Assisted Total Knee Arthroplasty

Advanced imaging used in robotic-assisted total knee arthroplasty (TKA), such as computed tomography (CT)-based three-dimensional (3D) planning, may provide an accurate means of implant sizing preoperatively. The purpose of this study was to examine preoperative CT-based implant planning accuracy for robotic-assisted TKA in patients who have (1) varus deformities, (2) valgus deformities, (3) neutral alignment, and (4) retained hardware. A total of 393 patients underwent a robotic-assisted TKA by a single surgeon received preoperative CT scans. The surgeon reviewed the CT-based model preoperatively and recorded the expected size of the components. The final implants used in each case were recorded and compared with the surgeon's preoperative plan. In all groups of patients, the surgeon's CT-based implant plan was within one size of the implant utilized 100% of the time for both the tibiae and femora. Overall, the surgeon was exactly matched in 319 (81%) and 315 (80%) cases for the femoral and tibial components, respectively. For the femoral component, the mean age for patients in whom the original plan was exactly matched was younger than those whose implants were upsized and older than patients those implants were downsized (p = 0.024). Other patient demographics and preoperative knee alignment were not associated with predictive accuracy for femoral or tibial components. Our results demonstrate how preoperative CT-based, 3D planning for robotic-assisted TKA is accurate to within one size of the components in every case (100%), and exactly matched in 80%. The results of this study are important because they demonstrate how CT-based preoperative implant planning for TKA is reliable and accurate across all native knee alignments and other patient-specific factors. In addition, they build on a previous study by the same single surgeon, demonstrating that predictive ability can improve over time. This may be important as we move toward more outpatient surgery with less ability for prostheses inventory at ambulatory sites.

Characteristics and trends of the most cited papers in robotic assisted arthroplasty

Purpose

To compile and analyze the top 50 most frequently cited articles published on robotic-assisted arthroplasty, allowing clinicians to effectively identify the most influential literature pertaining to this topic.

Methods

Guidelines set by the Preferred Reporting Items for Systematic Reviews were used as the foundation for data collection and analysis. All papers pertaining to robotic-assisted arthroplasty were retrieved using the Scopus database. Data including: manuscript title, authors, total citation count, level of evidence, journal, publication year, and country of publication was extracted from a final list of articles.

Results

The top 50 publications regarding robotic assisted arthroplasty were cited a total of 4530 times (including self-citations), with an average total of 91. The years with the most publications in the top 50 were: 2017, 2018, and 2019, producing 7, 6, and 5 papers, respectively. Only 4 papers in the top 50 were published prior to the year 2003. The most common level of evidence was level V, and the most common category was Clinical Outcomes (74%). The United States contributed half of the 50 articles, and Princess Grace Hospital and University of London were the most contributory institutions, each with 6 of the top 50 articles.

Conclusion

This analysis provides a comprehensive review of the most cited and influential papers in robotic-assisted arthroplasty. Understanding these trends in the literature will ultimately pave the way for physicians and researchers to continue to innovate and research in a targeted manner as they gain an understanding of what has been studied and what remains inadequately explored.

Level of evidence

3.

Comparison of Postoperative Instability and Acetabular Cup Positioning in Robotic-Assisted Versus Traditional Total Hip Arthroplasty

BACKGROUND

Robotic-assisted total hip arthroplasty (R-THA) affords precision yet uncertain clinical benefits. This study compares dislocation rates and related revisions between R-THA and manual total hip arthroplasty (M-THA). Secondarily we evaluated cup position, patient-reported outcome measures (PROMs), and postoperative complications.

METHODS

A three-surgeon cohort study was conducted on 2247 consecutive patients (1724 M-THA and 523 R-THA) who received a primary THA between January 2014 and June 2020 at a single hospital. Demographics, PROMs, emergency department visits, readmissions, and 90-day complications were collected via the Michigan Arthroplasty Registry Collaborative Quality Initiative. Chart review yielded instability occurrence with an average follow-up of 4 years. Multivariate regression analysis was performed, and a sample of 368 radiographs, including all dislocations, were assessed.

RESULTS

There were significantly lower rates of dislocation in R-THA (0.6%) vs M-THA (2.5%; Multivariate odds ratio 3.74, P < .046). All cases of unstable R-THA were successfully treated conservatively, whereas 46% of unstable M-THA were revised for recurrent instability. Cup anteversion (25.6° ± 5.4° R-THA vs 20.6° ± 7.6° M-THA) was greater, and cup inclination (42.5° ± 5.3° R-THA vs 47.0° ± 6.7° M-THA) was lower in the R-THA group (P < .05). No significant differences were noted for demographics, PROMs, or other complications (P > .05).

CONCLUSION

R-THA resulted in less than one-fourth the dislocation rate compared to M-THA and no revision for instability. It was associated with no difference in PROMs or other early complications. The influence of R-THA on stability goes beyond simply cup positioning and deserves further study.

A Newly Designed "SkyWalker" Robot Applied in Total Knee Arthroplasty: A Retrospective Cohort Study for Femoral Rotational Alignment Restoration

Objective

This study explored whether robotic arm‐assisted total knee arthroplasty (RATKA) has the advantage of restoring femoral rotational alignment compared to conventional total knee arthroplasty (COTKA).

Methods

Sixty patients (45 women and 15 men) attending our department from May 2019 to December 2020 were selected and divided into two groups, with 30 patients in each group, according to whether they underwent COTKA or RATKA. Femoral rotational alignment results, such as, posterior condylar angle (PCA), patella transverse axis‐femoral transepicondylar axis angle (PFA), radiological findings, such as, hip‐knee‐ankle angle (HKA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA), and operative data (operation time, intraoperative blood loss, tourniquet time, and length of stay (LOS), and clinical outcomes, such as maximum knee flexion angle (MKFA), Knee Society Score (KSS), and Western Ontario Mac Master University Index Score (WOMAC) were compared within and between the two groups.

Results

PCA and PFA in the RATKA group were (0.6 ± 0.3)° and (0.9 ± 0.3)°, respectively, which were smaller than (1.5 ± 2.0)° and (3.1 ± 1.1)° in the COTKA group (P < 0.05), and were closer to 0°; the differences in HKA, LDFA, and MPTA were not statistically significant. With the exception of the LDFA, the HKA, MPTA, PCA, and PFA improved in both groups after surgery (P < 0.05). The blood loss and the LOS of RATKA group were 192.3 ± 23.1 mL and 8.2 ± 1.4 days, which were less than 203.7 ± 29.8 mL and 9.3 ± 1.1 days of the COTKA group, but the operation time showed no statistically significant difference, and the tourniquet time was longer (P < 0.05). The MKFA in the RATKA group was (123.0 ± 3.7)°, which was greater than (116.3 ± 4.6)° in the COTKA group (P < 0.05). In terms of scores, the postoperative results were better than the preoperative results in both groups (P < 0.05). However, there was no statistically significant difference between the groups.

Conclusion

The accuracy of femoral rotational alignment reconstructed achieved by RATKA is significantly better than that of COTKA and is more conducive to the recovery of knee flexion function after surgery; although RATKA reduces intraoperative blood loss and postoperative LOS, the short‐term clinical efficacy comparison has not yet demonstrated the advantages of robotic technology, and a more optimized design is needed to improve the efficiency of RATKA surgery.

Robotic arm-assisted arthroplasty: The latest developments

Joint arthroplasty is an effective method for treating end-stage joint lesions and damages. Robotic arm-assisted arthroplasty, a rapidly developing technology that combines navigation technology, minimally invasive technology, and precise control technology of the robotic arm, can achieve accurate preoperative planning, optimal selection of implants, minimally invasive surgery, precise osteotomy, and accurate placement of the artificial joint. It has the characteristics of high accuracy and stability, and thus is more and more widely used in the field of joint surgery. In this paper, we systematically reviewed the application and clinical efficacy of robotic arm-assisted technology in hip and knee arthroplasty to provide reference for its future promotion.

[Short-term effectiveness of MAKO robot assisted complex total hip arthroplasty]

OBJECTIVE

To investigate the short-term effectiveness of MAKO robot assisted complex total hip arthroplasty (THA).

METHODS

The clinical data of 15 patients (17 hips) underwent MAKO robot assisted complex THA between May 2020 and June 2021 were analyzed retrospectively. There were 5 males and 10 females with the age ranged from 19 to 70 years (median, 49 years), included 9 cases (9 hips) of developmental dysplasia of the hip (Crowe type Ⅱ in 5 hips, type Ⅲ in 1 hip, and type Ⅳ in 3 hips), 1 case (2 hips) of rheumatoid arthritis, 2 cases (3 hips) of ankylosing spondylitis, 3 cases (3 hips) of secondary arthritis with a history of acetabular fracture and internal fixation. The acetabular cup abduction angle and anteversion angle were measured at 3 months after operation, and compared with those measured by MAKO robot system before and immediately after operation. The femoral offset and leg length discrepancy (LLD) were measured at 3 months after operation, which were compared with those before operation. Harris hip score (HHS) and visual analogue scale (VAS) score were used to evaluate hip function before operation and at 3 months after operation.

RESULTS

All 15 patients (17 hips) completed the operation successfully. The operation time was 75-175 minutes, with an average of 116.3 minutes; the intraoperative blood loss was 100-800 mL, with an average of 381.3 mL. Two patients were not included in the statistics because of intraoperative and postoperative complications, the remaining 13 patients (15 hips) had no serious complication such as vascular and nerve injuries, and 3 patients had intermuscular vein thrombosis. The 13 patients (15 hips) were followed up 3-15 months, with an average of 8 months. At last follow-up, the position of prosthesis did not change and there was no signs of loosening. There was no significant difference in acetabular abduction angle at immediate and 3 months after operation when compared with preoperative one ( P>0.05), and the acetabular anteversion angle was significantly lower than that before operation ( P<0.05). There was no significant difference in acetabular abduction angle and anteversion angle between at immediate and 3 months after operation ( P>0.05). The LLD, offset, HHS score, and VAS score were significantly improved at 3 months after operation when compared with preoperative ones ( P<0.05).

CONCLUSION

MAKO robot assisted complex THA can achieve good short-term effectiveness, improve the hip range of motion, reduce the length difference between bilateral lower limbs, and improve the quality of patients' life.

Robotics in orthopaedic surgery: why, what and how?

INTRODUCTION

Robotics applied to orthopedics has become an interesting topic both from the surgical point of view and the engineering one. The main goal of those systems is the enhancement of joint arthroplasty surgery, providing the robotic support to precisely and accurately prepare the bone, restore the limb alignment and the physiological kinematics of the joint. Various robotic systems are currently available on the market, each addressing specific kind of surgeries and characterized by a series of specific features that may involve different requirements and/or modus operandi.

MATERIAL AND METHODS

An overview of these devices was performed, addressing the different categories in which robots are subdivided in terms of: operations performed, requirements and level of interaction of the surgeon. The main models currently available on the market were addressed and relative studies in the literature were reported and compared, to highlight the benefits and drawbacks of the different technologies.

RESULTS

The different robotic systems were subdivided in: open/closed platform, image-based/imageless and active/passive/semi-active. Regardless of the typology of robotic system, the main aim is to improve precision and accuracy of the operation. It is to be noted that, regardless of the typology of robotic system, the surgeon is still in charge of the planning and approval of the operation: only the precise and consistent execution of his directives is entrusted to the robot. The positive factors have however to be weighed against the fact that robotic systems involve an important initial investment and most of the times require the surgeons and the staff to learn how to operate them (with a learning curve differing from system to system).

CONCLUSIONS

Each surgeon, when considering if and which robotic system to adopt, has to properly evaluate the different benefits and drawbacks involved to find the surgical robot that fits his needs the best.

[Short-term effectiveness of Mako robot-assisted total hip arthroplasty via posterolateral approach]

Objective

To explore the short-term effectiveness of Mako robot-assisted total hip arthroplasty (THA) via posterolateral approach.

Methods

The clinical data of 64 patients (74 hips) treated with Mako robot-assisted THA via posterolateral approach (robot group) between May 2020 and March 2021 were retrospectively analyzed and compared with the clinical data of 52 patients (55 hips) treated with traditional THA via posterolateral approach (control group) in the same period. There was no significant difference in general data such as gender, age, side, body mass index, disease type, and preoperative Harris score between the two groups ( P>0.05). The operation time, intraoperative blood loss, and complications were recorded and compared between the two groups. Acetabular inclination angle, acetabular anteversion angle, and lower limbs discrepancy were measured after operation. At last follow-up, the improvement of hip pain and function was evaluated by visual analogue scale (VAS) score, Harris score, and forgetting joint score (FJS-12).

Results

In the robot group, 3 patients (including 1 patient with acetabular fracture during operation) were converted to routine THA because the pelvic data array placed at the anterior superior iliac spine was loose, resulting in data error and unable to register the acetabulum; the other patients in the two groups completed the operation successfully. The operation time and intraoperative blood loss in the robot group were significantly higher than those in the control group ( P<0.05). All patients were followed up 1-10 months, with an average of 4.6 months. In the robot group, 1 patient with ankylosing spondylitis had acetabular prosthesis loosening at 2 days after operation, underwent surgical revision, and 10 patients had lower limb intermuscular vein thrombosis; in the control group, 1 patient had left hip dislocation and 5 patients had lower extremity intermuscular vein thrombosis; there was no complication such as sciatic nerve injury, incision exudation, and periprosthetic infection in both groups. There was no significant difference in the incidence of complications between the robot group and the control group (17.2% vs.11.5%) ( χ ²=0.732, P=0.392). At last follow-up, the acetabular anteversion angle and FJS-12 score in the robot group were was significantly greater than those in the control group, and the lower limbs discrepancy was significantly less than that in the control group ( P<0.05); there was no significant difference in acetabular inclination angle and VAS score between the two groups ( P>0.05). The Harris scores of the two groups were significantly improved when compared with those before operation ( P<0.05), but there was no significant difference in the difference of pre- and post-operative score between the two groups ( t=1.632, P=0.119).

Conclusion

Compared with traditional surgery, Mako robot-assisted THA can optimize the accuracy and safety of acetabular cup implantation, reduce the length difference of the lower limbs, and has a certain learning curve. Its long-term effectiveness needs further research to confirm.

What is the Level of Evidence Substantiating Commercial Payers' Coverage Policies for Total Joint Arthroplasty?

BACKGROUND

The prevalence of total joint arthroplasty (TJA) in the United States has drawn the attention of health care stakeholders. The payers have also used a variety of strategies to regulate the medical necessity of these procedures. The purpose of this study was to examine the level of evidence of the coverage policies being used by commercial payers in the United States.

METHODS

The references of the coverage policies of four commercial insurance companies were reviewed for type of document, level of evidence, applicability to a TJA population, and success of nonoperative treatment in patients with severe degenerative joint disease.

RESULTS

282 documents were reviewed. 45.8% were primary journal articles, 14.2% were level I or II, 41.2% were applicable to patients who were candidates for TJA, and 9.9% discussed the success of nonoperative treatment in patients who would be candidates for TJA.

CONCLUSION

Most of the references cited by commercial payers are of a lower level of scientific evidence and not applicable to patients considered to be candidates for TJA. This is relatively uniform across the reviewed payers. The dearth of high-quality literature cited by commercial payers reflects the lack of evidence and difficulty in conducting high level studies on the outcomes of nonoperative versus operative treatment for patients with severe, symptomatic osteoarthritis. Patients, surgeons, and payers would all benefit from such studies and we encourage professional societies to strive toward that end through multicenter collaboration.

Primary Robotic-Arm Assisted Total Hip Arthroplasty: An Analysis of 501 Hips With 44-Month Follow-up

The aim of this study was to report patient-reported outcome measurements in a large group of patients who underwent robotic-arm assisted primary total hip arthroplasty (THA). Prospectively collected data were retrospectively reviewed between April 2012 and May 2017. Primary THAs using the Mako robotic-arm assisted (Mako Surgical Corp [Stryker]) with minimum 2-year follow-up for Harris Hip Score (HHS) and Forgotten Joint Score-12 (FJS-12) were included. Exclusion criteria were body mass index (BMI) of 40 kg/m² or greater, age younger than 21 years, workers' compensation, or unwillingness to participate. Visual analog scale (VAS) score for pain and patient satisfaction score were obtained. Intraoperative measurements for leg length, global offset, acetabular inclination, and version were documented. A total of 501 hips were included, with 57.29% of the patients being female. Mean follow-up was 43.99±15.59 months. Mean age was 58.70±9.41 years. Mean BMI was 28.41±4.55 kg/m². Mean HHS was 90.87±13.45, mean FJS-12 was 79.97±25.87, mean VAS score was 1.20±2.06, and mean patient satisfaction score was 8.85±2.08. Intraoperative values for acetabular inclination and version were 40.0°±2.2° and 20.5°±2.4°, respectively. The rate of revision due to instability was 0.2%. Patients who received primary robotic-arm assisted THA reported excellent results at 44-month follow-up for multiple patient-reported outcome measurements. Consistency in acetabular cup placement accuracy was achieved regarding the Lewinnek and Callanan safe zones. [Orthopedics. 2021;44(2):70-76.].

Adoption of Robotic Arm-Assisted Total Hip Arthroplasty Results in Reliable Clinical and Radiographic Outcomes at Minimum Two-Year Follow Up

INTRODUCTION

Longevity and success of total hip arthroplasty (THA) is largely dependent on component positioning. While use of robotic platforms can improve this positioning, published evidence on its clinical benefits is limited. Therefore, the aim of this study was to assess the clinical outcomes of THA with robotic surgical assistance.

MATERIALS AND METHODS

We conducted an analysis of robotic arm-assisted primary THAs performed by a single surgeon utilizing a posterior approach. A total of 99 patients (107 cases) who had a minimum two-year follow up were identified. Their mean age was 61 years (range, 33 to 84 years), and their mean body mass index was 30.5 kg/m2 (range, 18.5 to 49.1 kg/m2). There were 56% female patients and primary osteoarthritis was the principal hip diagnosis in 88.8%. Operative times, lengths of hospital stay, and discharge dispositions were recorded, along with any complications. Modified Harris Hip Scores (HHS) were calculated to quantify clinical outcomes.

RESULTS

Mean postoperative increases in HHS at 2- to 5.7-year follow up was 33 points (range, 6 to 77 points). There were no complications attributable to the use of robotic assistance. Surgical-site complications were rare; one case underwent a revision for prosthetic joint infection (0.93%) but there were no dislocations, periprosthetic fractures, or cases of mechanical implant loosening. There was no evidence of progressive radiolucencies or radiographic failure.

DISCUSSION

Robotic arm-assisted THA resulted in low complication rates at minimum two-year follow up, with clinical outcomes comparable to those reported with manual surgery.1-4 The haptically-guided acetabular bone preparation enabled reliable cementless acetabular fixation and there were no adverse events related to the use of the robot. Dislocations were avoided in this case series. Randomized controlled clinical trials are needed to compare manual to robotic surgery and to investigate whether the precision found with this functional planning will reliably reduce the incidence of dislocations.

Robotic-assisted unicompartmental knee arthroplasty: a review

Purpose

Presented here is an up-to-date review concerning robotic-assisted unicompartmental knee arthroplasty (rUKA), including its rationale, operative system, pros and cons.

Methods

We did a systematic research in electronic databases, including PubMed, Cochrane Library, Web of Science, and Embase up to March 30, 2020 to retrieve literature pertaining to rUKA. The search strategies “(robotic* AND knee arthroplasty OR knee replacement)” and “(knee arthroplasty OR knee replacement NOT total)” were used. Studies describing rUKA and clinical trials, dry bone or cadaveric researches regarding technologies, positioning, alignment, function, or survivorship of implants were included in this review. All retrieved studies were first browsed for eligibility on the basis of title and abstract, and the selected studies were further evaluated by reading full text for final inclusion.

Results

Robotic-assisted technology has been found to increase the accuracy of bone preparation and implant placement, reduce technical variability and outliers, and enhance reproduction of limb alignment. Additionally, early clinical outcomes were excellent, but mid-term follow-up showed no superiority in component survivorship. The potential drawbacks of the robotic-assisted technology include relatively-low time- and cost-effectiveness, development of some rUKA-related complications, and lack of support by high-quality literature.

Conclusion

This review shows that rUKA can decrease the number of outliers concerning the optimal implant positioning and limb alignment. However, due to absence of extensive studies on clinical outcomes and long-term results, it remains unclear whether the improved component positioning translates to better clinical outcomes or long-term survivorship of the implant. Nevertheless, since an accurate implant position is presumably beneficial, robotic-assisted technology is worth recommendation in UKA.

Conversion of Hip Arthrodesis Using Robotic Arm Technology

Recent advancements in computer-assisted surgery have led to a renewed interest in robotic-assisted hip arthroplasty. This technology assists with component position which is especially useful in prior trauma or dysplasia cases. We present a case of a surgical hip fusion conversion to total hip arthroplasty with the use of robotic-assisted technology. Enhanced preoperative planning with the ability to manipulate implant position before execution can be invaluable during complex procedures. Further research is warranted before revision cases using computerized navigation systems becomes more prevalent.

The current state of robotics in total knee arthroplasty

Robotic total knee arthroplasty (TKA) has demonstrated improved component positioning and a reduction of alignment outliers with regard to pre-operative planning.

Early robotic TKA technologies were mainly active systems associated with significant technical and surgical complications.

Current robotic TKA systems are predominantly semi-active with additional haptic feedback which minimizes iatrogenic soft tissue injury compared to conventional arthroplasty and older systems.

Semi-active systems demonstrate advantages in terms of early functional recovery and hospital discharge compared to conventional arthroplasty.

Limitations with current robotic technology include high upfront costs, learning curves and lack of long-term outcomes.

The short-term gains and greater technical reliability associated with current systems may justify the ongoing investment in robotic technology.

Further long-term data are required to fully ascertain the cost-effectiveness of newer robotic systems.

Cite this article: EFORT Open Rev 2021;6:270-279. DOI: 10.1302/2058-5241.6.200052

Value of 3D preoperative planning for primary total hip arthroplasty based on artificial intelligence technology

Background

Accurate preoperative planning is an important step for accurate reconstruction in total hip arthroplasty (THA). Presently, preoperative planning is completed using either a two-dimensional (2D) template or three-dimensional (3D) mimics software. With the development of artificial intelligence (AI) technology, AI HIP, a planning software based on AI technology, can quickly and automatically identify acetabular and femur morphology, and automatically match the optimal prosthesis size. However, the accuracy and feasibility of its clinical application still needs to be further verified. The purposes of this study were to investigate the accuracy and time efficiency of AI HIP in preoperative planning for primary THA, compared with 3D mimics software and 2D digital template, and further analyze the factors that influence the accuracy of AI HIP.

Methods

A prospective study was conducted on 53 consecutive patients (59 hips) undergoing primary THA with cementless prostheses in our department. All preoperative planning was completed using AI HIP as well as 3D mimics and 2D digital template. The predicted component size and the actual implantation results were compared to determine the accuracy. The templating time was compared to determine the efficiency. Furthermore, the potential factors influencing the accuracy of AI HIP were analyzed including sex, body mass index (BMI), and hip dysplasia.

Results

The accuracy of predicting the size of acetabular cup and femoral stem was 74.58% and 71.19%, respectively, for AI HIP; 71.19% (P = 0.743) and 76.27% (P = 0.468), respectively, for 3D mimics; and 40.68% (P < 0.001) and 49.15% (P = 0.021), respectively, for 2D digital templating. The templating time using AI HIP was 3.91 ± 0.64 min, which was equivalent to 2D digital templates (2.96 ± 0.48 min, P < 0.001), but shorter than 3D mimics (32.07 ± 2.41 min, P < 0.001). Acetabular dysplasia (P = 0.021), rather than sex and BMI, was an influential factor in the accuracy of AI HIP templating. Compared to patients with developmental dysplasia of the hip (DDH), the accuracy of acetabular cup in the non-DDH group was better (P = 0.021), but the difference in the accuracy of the femoral stem between the two groups was statistically insignificant (P = 0.062).

Conclusion

AI HIP showed excellent reliability for component size in THA. Acetabular dysplasia may affect the accuracy of AI HIP templating.

New Technologies in Knee Arthroplasty: Current Concepts

Total knee arthroplasty (TKA) is an effective treatment for severe osteoarthritis. Despite good survival rates, up to 20% of TKA patients remain dissatisfied. Recently, promising new technologies have been developed in knee arthroplasty, and could improve the functional outcomes. The aim of this paper was to present some new technologies in TKA, their current concepts, their advantages, and limitations. The patient-specific instrumentations can allow an improvement of implant positioning and limb alignment, but no difference is found for functional outcomes. The customized implants are conceived to reproduce the native knee anatomy and to reproduce its biomechanics. The sensors have to aim to give objective data on ligaments balancing during TKA. Few studies are published on the results at mid-term of these two devices currently. The accelerometers are smart tools developed to improve the TKA alignment. Their benefits remain yet controversial. The robotic-assisted systems allow an accurate and reproducible bone preparation due to a robotic interface, with a 3D surgical planning, based on preoperative 3D imaging or not. This promising system, nevertheless, has some limits. The new technologies in TKA are very attractive and have constantly evolved. Nevertheless, some limitations persist and could be improved by artificial intelligence and predictive modeling.

Robotics in total hip arthroplasty: a review of the evolution, application and evidence base

Robotic systems used in orthopaedics have evolved from active systems to semi-active systems.

Early active systems were associated with significant technical and surgical complications, which limited their clinical use.

The new semi-active system Mako has demonstrated promise in overcoming these limitations, with positive early outcomes.

There remains a paucity of data regarding long-term outcomes associated with newer systems such as Mako and TSolution One, which will be important in assessing the applicability of these systems.

Given the already high satisfaction rate of manual THA, further high-quality comparative studies are required utilizing outcome scores that are not limited by high ceiling effects to assess whether robotic systems justify their additional expense.

Cite this article: EFORT Open Rev 2020;5:866-873. DOI: 10.1302/2058-5241.5.200037

The Use of Robotic-Assisted Total Hip Arthroplasty in Developmental Dysplasia of the Hip

BACKGROUND

Total hip arthroplasty (THA) is an effective operation for patients with hip osteoarthritis; however, patients with hip dysplasia present a particular challenge. Our novel study examined the effect of robot-assisted THA in patients with hip dysplasia.

METHODS

We retrospectively reviewed patients with developmental dysplasia of the hip undergoing primary THA using robotic arm assistance at 2 institutions from January 2010 to January 2017. Patients undergoing revision arthroplasty were excluded. Preoperatively, all patients underwent a computed tomography scan so that 3-dimensional templating could be performed. Hip range of motion (ROM) and clinical leg length discrepancy were recorded preoperatively. Two independent observers calculated Crowe and Hartofilakidis grades for each operative hip. At the final follow-up, hip ROM, postoperative complications, and modified Harris Hip scores were obtained.

RESULTS

Seventy-nine patients underwent THA because of degenerative joint disease in the setting of developmental dysplasia of the hip. There were 56 females and 23 males with a mean age of 45 years (range: 26-64 years). We found that components were placed according to the preoperative plan, that there was an improvement in the modified Harris hip score from 29 to 86 (P < .001), an improvement in the hip ROM (flexion improvement from 66° to 91°, P < .0001), and a correction of leg length discrepancy (17.1 vs 4 mm, P < .0002). There were no complications during the short-term interim follow-up (mean: 3.1 years).

CONCLUSIONS

Robot-assisted THA can be a useful method to ensure adequate component positioning and excellent outcomes in patients with hip dysplasia.

LEVEL OF EVIDENCE

Level III, Retrospective.

Current concepts in robotic total hip arthroplasty

INTRODUCTION

Total hip replacement provides mostly fair functional and clinical results. Many factors play an essential role in hip stability and long-term outcomes. Surgical positioning remains fundamental for obtaining accurate implant fit and prevent hip dislocation or impingement. Different categories of robotic assistance have been established throughout the previous years and all of the technologies target accuracy and reliability to reduce complications, and enhance clinical outcomes.

MATERIALS AND METHODS

An overview is proposed over the principles of robotic assistance in hip arthroplasty surgery. Accuracy, reliability, management of the bone stock, clinical outcomes, constraints and limits of this technology are reported, based on recent literature.

RESULTS

Potential advantages regarding pre-operative planning accuracy, cup positioning, maintenance of the center of rotation, preservation of an adequate bone stock nay clinical short- and mid-term outcomes are balanced with some reported disadvantages and limits like hip anatomical specificity, cost-effectiveness, engineering dependence.

DISCUSSION

The use of robotic-assisted THA presents clear and evident benefits related to accurate implant positioning and maintenance of a minimal bone while allowing. For some authors, an early improvement in functional results and patient's recovery. This technology demonstrated a shorter surgical time and a short learning curve required to optimize its use and this technology presents promising outcomes and results and potential use in routine clinical application but its limitation of use is still present especially the cost of the robot, the need for the presence of an engineer during the surgery, its availability of use in all hospitals as well as the difficulty presented in dysplastic or dysmorphic hip joints.

Accuracy of tibial component positioning in the robotic arm assisted versus conventional unicompartmental knee arthroplasty

BACKGROUND

Our study aims to determine the planned accuracy of the tibial component placement in robotic arm assisted unicompartmental knee arthroplasty (UKA) versus the conventional jig based UKA of the initial cases done in India for the first time with this particular robotic system.Materials & Methods: Study group 1 consisted of patients who underwent robotic arm (MAKO, Stryker, USA) assisted UKA. Group 2 consists of patients who underwent a standard conventional jig based (Oxford knee, Biomet, UK). Post-operative radiographs were taken to determine the Tibial Implant position and orientation which were compared to their preoperative plan respectively by two independent observers. The mean error value was obtained for both study groups respectively and compared to determine the accuracy of the post-operative tibial implant placement.

RESULTS

In the Robotic arm assisted UKA, the deviation of post-operative varus angle from preoperative planned angle was about 0.43° and post-operative Tibial slope alignment differed from preoperative plan was 0.41°. In the Conventional UKA group post-operative varus angle differed from preoperative planned angle by about 2.12° and post-operative Tibial slope alignment deviation from preoperative plan was 2.47°.

CONCLUSIONS

Robotic arm assisted system was more accurate compared to the conventional jig-based technique in achieving the planned orientation and alignment of the tibial implant in the initial learning phase of this particular Robotic System used for the first time in India.

MESH TERMS

partial knee replacement, robotic assisted surgery.

Minimum 5-Year Outcomes of Robotic-assisted Primary Total Hip Arthroplasty With a Nested Comparison Against Manual Primary Total Hip Arthroplasty: A Propensity Score-Matched Study

BACKGROUND

Robotic-assisted technology has been a reliable tool in enhancing precision and accuracy of cup placement in total hip arthroplasty (THA). Still, questions remain on the clinical benefit of this technology.

METHODS

The purposes of the ongoing study were (1) to report on minimum 5-year outcomes in patients who underwent robotic-assisted primary THA (rTHA), (2) to compare those outcomes to a propensity score-matched manual primary THA (mTHA) control group, and (3) to compare radiographic measures between the groups regarding acetabular cup placement. Prospectively collected patient data were retrospectively reviewed for primary THA recipients during June 2008 to July 2013. Patients with minimum 5-year follow-up for Harris Hip Score, Forgotten Joint Score-12, Veterans RAND-12 Mental, Veterans RAND-12 Physical, 12-Item Short Form Survey Mental, 12-Item Short Form Survey Physical, visual analog scale, and satisfaction were included. Patient-reported outcomes, cup placement, and revision rate of the rTHA group were compared with those of a propensity score-matched mTHA control group.

RESULTS

Sixty-six rTHAs were matched to 66 mTHAs. The rTHA group reported significantly higher Harris Hip Score, Forgotten Joint Score-12, Veterans RAND-12 Physical, and 12-Item Short Form Survey Physical (P < 0.001, P = 0.002, P = 0.002, P = 0.001). The acetabular implant placement by rTHA had a 9 and 4.7-fold reduced risk of placement outside the Lewinnek and Callanan safe zones, respectively (relative risk, 0.11 [95% confidence interval, 0.03 to 0.46]; P = 0.002; relative risk, 0.21 [95% confidence interval, 0.01 to 0.47]; P = 0.001). In addition, rTHA recipients had lesser absolute values of leg length discrepancy and global offset (P = 0.091, P = 0.001).

CONCLUSIONS

Patients who received rTHA reported favorable outcomes at minimum 5-year follow-up. Furthermore, in comparison to a propensity score pair-matched mTHA group, rTHAs reported higher patient-reported outcome scores and had 89% reduced risk of acetabular implant placement beyond the Lewinnek safe zone and 79% reduced risk of placement beyond the Callanan safe zone.

LEVEL OF EVIDENCE

Level III.

Personalized Cup Positioning Guides Improved Cup Positioning and Hip Ranges of Motion in Robotic Assisted Total Hip Arthroplasty

Objective

Precise hip cup positioning is essential for the prevention of component impingement and dislocation in robotic assisted total hip arthroplasty (THA). Currently, the robotic system uses a mechanical alignment guide (MAG) for cup placement, which is one-size-fits-all, and the optimal cup positioning is controversial. Robotic assisted THA has not used any personalized cup positioning guides. The goal of this study was to identify an optimal guide for cup placement in robotic assisted THA to improve prognosis and life quality after THA.

Materials and Methods

Pelvis and femoral CT data of 47 participants were retrospectively collected for preoperative planning of robotic THA. The universal MAG guide and three personalized guides, including acetabular rim labrum guide (ARLG), transverse acetabular ligament guide (TALG), and ischiatic-pubis line guide (IPLG), were used to pose cups in the acetabulum of each participant. The position of cups was evaluated by inclination and anteversion; the function of hip joints was evaluated by hip ranges of motion, including abduction, adduction, extension, flexion, internal rotation, and external rotation.

Results

In terms of cup positioning, ARLG provided a bigger cup inclination (p < 0.0001), while IPLG and TALG provided smaller cup inclination (p < 0.001) than MAG; the three personalized guides provided larger cup anteversion (p < 0.0001) than MAG. In terms of HROMs, compared with the use of MAG, the use of three personalized guides significantly decreased abduction (p < 0.0001), extension (p < 0.0001), and external rotation (p < 0.0001), but increased significantly flexion (p < 0.0001) and internal rotation (p < 0.0001); the use of ARLG significantly reduced adduction (p < 0.0001), but the use of IPLG and TALG increased adduction (p < 0.0001).

Conclusion

Compared with MAG, personalized guides provided greater flexion and internal rotation, which may reduce the risk of posterior dislocation. Among the three personalized guides, IPLG is the most reliable one for the preoperative planning of robotic assisted THA.

Trends and patient factors associated with technology-assisted total hip arthroplasty in the United States from 2005 to 2014

Background

Technology-assisted total hip arthroplasty (TA-THA) using either computer-assisted navigation or robotic assistance has become increasingly more popular. The purpose of this study was to examine the trends and patient factors associated with TA-THA.

Methods

This is a retrospective review utilizing the National Inpatient Sample, a large national database incorporating inpatient hospitalization information. International Classification of Diseases, 9th Revision codes were used to identify patients with hip osteoarthritis who underwent primary total hip arthroplasty (THA). Patients were then separated into those who underwent TA-THA or conventional THA. Outcomes of interest included annual TA-THA utilization; patient and hospital characteristics associated with TA-THA; and trends for length of stay (LOS), cost, and discharge to home.

Results

From 2005 to 2014, a total of 2,588,304 patients with hip osteoarthritis who underwent THA were identified in the National Inpatient Sample database. Of those, 39,700 (1.5%) underwent TA-THA. The number of TA-THA procedures increased from 178 (0.1% of all THA) in 2005 to 10,045 (3.0% of all THA) in 2014, which represented a 30-fold increase in incidence (P-trend <.0001). TA-THA was associated with Hispanic race, higher patient income, and the Western region of the United States. During the study period, there was a trend toward decreased LOS and increased discharge to home for both TA-THA and conventional THA. TA-THA was associated with higher inpatient cost.

Conclusion

TA-THA is being increasingly used in the United States and is associated with specific patient factors. However, the value of TA-THA compared to conventional THA remains unclear and should be assessed with future research.

Level of Evidence

III (retrospective cohort study).

Robotic-assisted compared with conventional total hip arthroplasty: systematic review and meta-analysis

BACKGROUND

Robotic-assisted total hip arthroplasty (THA) allows for accurate preoperative planning and component positioning, potentially enhancing implant survival and long-term outcomes. The relative efficacy and safety of robotic-assisted and conventional THA, however, are unclear. This systematic review and meta-analysis compared the safety and efficacy of robotic-assisted and conventional THA.

METHODS

Medline, Embase and the Cochrane Library were comprehensively searched in September 2017 to identify studies comparing the safety and efficacy of robotic-assisted and conventional THA. Seven studies were included. Data of interest were extracted and analysed using Review Manager 5.3.

RESULTS

The seven included studies involved 1516 patients, with 522 undergoing robotic-assisted and 994 undergoing conventional THA. Compared with conventional THA, robotic-assisted THA was associated with longer surgical time (not significant); lower intraoperative complication rates (OR: 0.12, 95% CI: 0.05 to 0.34, p<0.0001 I²); better cup placement, stem placement and global offset and a higher rate of heterotopic ossifications. Functional scores, limb length discrepancy and rates of revision and stress shielding were similar in the two groups. The relative amount of blood loss was unclear.

CONCLUSION

The results of this meta-analysis suggest that robotic-assisted THA has certain advantages over conventional THA, including the results of component positioning and rates of intraoperative complications. Additional comparative studies are required to determine the long-term clinical outcomes of robotic-assisted THA.

Robotics in Arthroplasty: A Comprehensive Review

Robotic-assisted orthopedic surgery has been available clinically in some form for over 2 decades, claiming to improve total joint arthroplasty by enhancing the surgeon's ability to reproduce alignment and therefore better restore normal kinematics. Various current systems include a robotic arm, robotic-guided cutting jigs, and robotic milling systems with a diversity of different navigation strategies using active, semiactive, or passive control systems. Semiactive systems have become dominant, providing a haptic window through which the surgeon is able to consistently prepare an arthroplasty based on preoperative planning. A review of previous designs and clinical studies demonstrate that these robotic systems decrease variability and increase precision, primarily focusing on component positioning and alignment. Some early clinical results indicate decreased revision rates and improved patient satisfaction with robotic-assisted arthroplasty. The future design objectives include precise planning and even further improved consistent intraoperative execution. Despite this cautious optimism, many still wonder whether robotics will ultimately increase cost and operative time without objectively improving outcomes. Over the long term, every industry that has seen robotic technology be introduced, ultimately has shown an increase in production capacity, improved accuracy and precision, and lower cost. A new generation of robotic systems is now being introduced into the arthroplasty arena, and early results with unicompartmental knee arthroplasty and total hip arthroplasty have demonstrated improved accuracy of placement, improved satisfaction, and reduced complications. Further studies are needed to confirm the cost effectiveness of these technologies.