Robot-assisted total hip arthroplasty: Clinical outcomes and complication rate

Driving Forces for Outpatient Total Hip and Knee Arthroplasty with Enhanced Recovery After Surgery Protocols: A Narrative Review

PURPOSE OF REVIEW

To explore the recent developments and trends in the anesthetic and surgical practices for total hip and total knee arthroplasty and discuss the implications for further outpatient total joint arthroplasty procedures.

RECENT FINDINGS

Between 2012 and 2017 there was an 18.9% increase in the annual primary total joint arthroplasty volume. Payments to physicians falling by 7.5% (14.9% when adjusted for inflations), whereas hospital reimbursements and charges increased by 0.3% and 18.6%, respectively. Total knee arthroplasty and total hip arthroplasty surgeries were removed from the Medicare Inpatient Only in January 2018 and January 2020, respectively leading to same-day TKA surgeries increases from 1.2% in January 2016 to 62.4% by December 2020 Same-day volumes for THA surgery increased from 2% in January 2016 to 54.5% by December 2020. Enhanced Recovery After Surgery (ERAS) protocols have revolutionized modern anesthesia and surgery practices. Centers for Medicare Services officially removed total joint arthroplasty from the inpatient only services list, opening a new door for improved cost savings to patients and the healthcare system alike. In the post-COVID healthcare system numerous factors have pushed increasing numbers of total joint arthroplasties into the outpatient, ambulatory surgery center setting. Improved anesthesia and surgical practices in the preoperative, intraoperative, and postoperative settings have revolutionized pain control, blood loss, and ambulatory status, rendering costly hospital stays obsolete in many cases. As the population ages and more total joint procedures are performed, the door is opening for more orthopedic procedures to exit the inpatient only setting in favor of the ambulatory setting.

Fewer Dislocations After Total Hip Arthroplasty With Robotic Assistance or Fluoroscopic Guidance

BACKGROUND

Computer navigation and robotic assistance may reduce total hip arthroplasty (THA) dislocations by improving the accuracy and precision of component positioning. We investigated dislocation rates for THAs using conventional techniques, robotic assistance, and computer navigation, while controlling for surgical approach, dual mobility (DM) use, and fluoroscopic guidance.

METHODS

We reviewed 11,740 primary THAs performed between June 2016 and December 2022, including 5,873 conventional, 1,293 with robotic-arm assistance, and 4,574 with navigation. The approach was posterior in 6,580 (56.0%), anterior in 4,342 (37.0%), and lateral in 818 (7.0%). A DM was used in 10.4%. Fluoroscopy was used in 3,653 cases and only with the anterior approach. Multivariate analyses yielded odds ratios (OR) for dislocation and revision. Additional regression analyses for dislocation were performed for approach and DM.

RESULTS

Raw dislocation rates were as follows: conventional 1.2%, robotic 0.4%, navigation 0.9%, anterior with fluoroscopy 0.4%, anterior without fluoroscopy 2.3%, posterior 1.3%, and lateral 0.5%. Upon multivariate analysis, use of robotics was found to be associated with significantly reduced dislocation risk compared to conventional (OR: 0.3), as did anterior (OR: 0.6) compared to posterior approach; navigation and lateral approach were not found to be associated with a significant reduction in risk. For the anterior approach, multivariate analysis demonstrated that fluoroscopy significantly reduced dislocation risk (OR: 0.1), while DM, robotics, and navigation were not significant. For the posterior approach, the dislocation risk was lower with robotics than with conventional (OR: 0.2); the use of navigation or DM did not demonstrate a significant reduction in risk.

CONCLUSIONS

The use of robotics was associated with a reduction in dislocations for this cohort overall. Further, fluoroscopy in the anterior approach and robotic assistance in the posterior approach were both associated with decreased dislocation risk. The role of imageless computer navigation and DM implants requires further study.

Reduction in rate of implant waste associated with robotic-assisted total hip arthroplasty

Aims

Implant waste during total hip arthroplasty (THA) represents a significant cost to the USA healthcare system. While studies have explored methods to improve THA cost-effectiveness, the literature comparing the proportions of implant waste by intraoperative technology used during THA is limited. The aims of this study were to: 1) examine whether the use of enabling technologies during THA results in a smaller proportion of wasted implants compared to navigation-guided and conventional manual THA; 2) determine the proportion of wasted implants by implant type; and 3) examine the effects of surgeon experience on rates of implant waste by technology used.

Methods

We identified 104,420 implants either implanted or wasted during 18,329 primary THAs performed on 16,724 patients between January 2018 and June 2022 at our institution. THAs were separated by technology used: robotic-assisted (n = 4,171), imageless navigation (n = 6,887), and manual (n = 7,721). The primary outcome of interest was the rate of implant waste during primary THA.

Results

Robotic-assisted THA resulted in a lower proportion (1.5%) of implant waste compared to navigation-guided THA (2.0%) and manual THA (1.9%) (all p < 0.001). Both navigated and manual THA were more likely to waste acetabular shells (odds ratio (OR) 4.5 vs 3.1) and polyethylene liners (OR 2.2 vs 2.0) compared to robotic-assisted THA after adjusting for demographic and perioperative factors, such as surgeon experience (p < 0.001). While implant waste decreased with increasing experience for procedures performed manually (p < 0.001) or with navigation (p < 0.001), waste rates for robotic-assisted THA did not differ based on surgical experience.

Conclusion

Robotic-assisted THAs wasted a smaller proportion of acetabular shells and polyethylene liners than navigation-guided and manual THAs. Individual implant waste rates vary depending on the type of technology used intraoperatively. Future studies on implant waste during THA should examine reasons for non-implantation in order to better understand and develop methods for cost-saving.

A new seven-axis robotic-assisted total hip arthroplasty system improves component positioning: a prospective, randomized, multicenter study

This study compared the radiologic and clinical outcomes of a new seven-axis robotic-assisted total hip arthroplasty (THA) and conventional THA. Hundred and four patients were randomly assigned to two groups-the robotic-assisted THA group (RAS group) and the conventional THA group (CON group). The preoperative and postoperative Harris Hip score (HHS), acetabular inclination, anteversion, femoral offset, and leg length discrepancy (LLD) were compared. During the follow-up, no patients had any complications that could be associated with the use of the robot. The proportion of acetabular cups in the safety zone was significantly higher in the RAS group than that in the CON group. The two groups had significantly different mean absolute difference of inclination and anteversion. There was no significant difference in the postoperative HHSs, changes in HHSs, femoral offset, and lower limb length between the two groups. The seven-axis robotic-assisted THA system is safe and effective, and leads to better acetabulum cup positioning compared to conventional THA. The improvements observed in the HHS, LLD, and femoral offset in the RAS group were similar to those in the CON group.Clinical trial registration time: 19/05/2022.Clinical trial registration number: ChiCTR2200060115.

Robot-Assisted Total Hip Arthroplasty Demonstrates Improved 90-Day Clinical and Patient-Reported Outcomes

Background

The utilization of technology, including robotics and computer navigation, in total hip arthroplasty (THA) has been steadily increasing; however, conflicting data exists regarding its effect on short-term clinical and patient-reported outcomes. Therefore, this study sought to explore the association between different surgical technologies and postoperative outcomes following THA.

Methods

We retrospectively reviewed 9892 primary THA cases performed by 62 surgeons from a single institution from September 2017 to November 2022. Three cohorts were created based on the utilization of technology: conventional (no technology), navigation, or robotics. Patient demographics, clinical outcomes, and patient-reported outcome measures were collected over the first 90 days following surgery. This data was compared using analysis of variance and multivariate logistic regressions. In total, 4275 conventional, 4510 navigation, and 1107 robotic cases were included in our analyses.

Results

The robotic cohort achieved a perfect Activity Measure for Post-Acute Care (AM-PAC) score earliest (0.1 days, P < .001). After adjusting for potential confounding variables, use of robotic assistance was associated with greater odds of achieving a perfect AM-PAC score on postoperative day 0 (odds ratio 1.6, P < .001) and greater odds of having length of stay shorter than 24 hours (odds ratio 2.3, P < .001) compared to no technology use in THA. Hip dysfunction and Osteoarthritis Outcome Score, Joint Replacement and Patient-Reported Outcomes Measurement Information System Pain Interference scores showed the greatest improvement in the robotic cohort at both 6 weeks and 3 months following surgery.

Conclusions

The present study demonstrates favorable clinical and patient-reported outcomes in the first 90 days following surgery for patients undergoing robot-assisted THA compared to conventional and navigation-assisted THA.

A new designed full process coverage robot-assisted total hip arthroplasty: a multicentre randomized clinical trial

OBJECTIVE

To compare the effect of a new complete robot-assisted total hip arthroplasty (RA-THA) with that of the manual total hip arthroplasty (MTHA) and to verify the accuracy and safety of the former.

METHODS

Overall, 148 patients were enroled from 3 March 2021 to 28 December 2021 in this study and classified into RA-THA ( n =74 patients) and MTHA ( n =74 patients) groups. The sex, age, operative side, BMI, diagnosis, other basic information, operative time, acetabular prosthesis anteversion and inclination, femoral prosthesis anteversion and angulation, femoral prosthesis filling rate, leg length discrepancy (LLD), Harris hip score, and visual analogue scale (VAS) score of the two groups were compared.

RESULTS

No significant differences were observed in the two groups regarding sex, age, operative side, BMI, diagnosis, Harris hip score, VAS score, acetabular inclination, acetabular prosthesis anteversion, femoral prosthesis anteversion, combined anteversion, and femoral prosthesis filling rate ( P >0.05). The operative time was significantly longer in the RA-THA group than in the MTHA group (106.71±25.22 min vs. 79.42±16.16 min; t=7.30, P <0.05). The femoral angulation (1.78°±0.64°) and LLD (2.87±1.55 mm) in the RA-THA group were significantly lesser than those in the MTHA group (2.22°±1.11° and 5.81±6.27 mm, respectively; t=-2.95 and t=-3.88, P <0.05).

CONCLUSION

The complete RA-THA has some advantages over the traditional procedure in restoring the lower limb length and controlling the femoral prosthesis angulation. Thus, this study verifies the accuracy and safety of the robot-assisted system.

[Translated article] Clinical results of total hip arthroplasty assisted by robotic arm in Spain: Preliminary study

OBJECTIVES

Clinical, radiological and functional results of the first Spanish series of patients undergoing total hip arthroplasty assisted by Mako® (Stryker) robotic arm at the Hospital Clínico San Carlos (HCSC) in Madrid.

MATERIAL AND METHODS

Prospective and descriptive study analyzing the first 25 patients who underwent robotic-assisted THA at the HCSC, with a minimum follow-up of 4 months. Demographics, imaging studies (Mako® processing, Rx and CT), clinical parameters, functionality (modified Harris) and associated complications were evaluated.

RESULTS

Average age was 67.2 years (min 47, max 88), being 56% male population sample. 88% involves primary coxarthrosis, 4% post-traumatic coxarthrosis, 4% secondary avascular necrosis and 4% secondary femoroacetabular impingement. Average surgery time was 116.9min (min 92, max 150). The average time of the first five surgeries was 122.6min, and, regarding the last five interventions, it was 108.2min. Found medical intraoperative complications were four intraoperative markers loss. Average admission time was 4.4days (min 3, max 7), with an average postoperative haemoglobin decrease of 3.08±1.08g/dl, requiring a transfusion in 12% of the cases. Three medical complications have been registered in the meantime of the admission, with a relevant case of a confusional syndrome and a fall, which resulted in a non-displaced AG1 periprosthetic fracture. The analysis of the positioning of registered implants with Mako® system shows 40.55±1.53 acetabular inclination degrees and 12.2±3.6 acetabular anteversion degrees. The postoperative image study carried out on patients, are consistent with Mako® results, as it shows an acetabular inclination of 41.2±1.7 in Rx, as well as acetabular anteversion of 16±4.6 in CT. Hip length variance ranges depending on preoperative values of 3.91mm (SD: 3.9; min -12, max 3) to 1.29mm (SD: 1.96) after surgery registered with Mako®, with an increase of an average hip length of 5.64mm (SD: 3.35). Rx simple study results show a postoperative difference between both hips of 0.5±3.08mm, which is consistent with Mako® results. Native femoral offset was stable after surgery with a showing difference both pre and post operative of the intervened hip of 0.1mm (SD: 3.7), registered with Mako®. Preoperatory modified Harris punctuation was 41.6±13.3, improving to postoperative values of 74.6±9.7 after four months since the surgery. No complications were registered in immediate postoperative (4 months).

CONCLUSIONS

Total hip arthroplasty robot-assisted achieves an adequate precision and repeatability of the implant positioning and the postoperative hip dysmetry without showing an increase of associated complications to the technique applied. Surgery time, complications and functional results in a short-time period are similar to conventional techniques applied to great series previously published.

Clinical results of total hip arthroplasty assisted by robotic arm in Spain: Preliminary study

OBJECTIVES

Clinical, radiological and functional results of the first Spanish series of patients undergoing total hip arthroplasty assisted by Mako® (Stryker) robotic arm at the Hospital Clínico San Carlos (HCSC) in Madrid.

MATERIAL AND METHODS

Prospective and descriptive study analyzing the first 25 patients who underwent robotic-assisted THA at the HCSC, with a minimum follow-up of 4months. Demographics, imaging studies (Mako® processing, Rx and CT), clinical parameters, functionality (modified Harris) and associated complications were evaluated.

RESULTS

Average age was 67.2years (min 47, max 88), being 56% male population sample. 88% involves primary coxarthrosis, 4% post-traumatic coxarthrosis, 4% secondary avascular necrosis and 4% secondary femoroacetabular impingement. Average surgery time was 116.9min (min 92, max 150). The average time of the first five surgeries was 122.6min, and, regarding the last five interventions, it was 108.2min. Found medical intraoperative complications were four intraoperative markers loss. Average admission time was 4.4days (min 3, max 7), with an average postoperative hemoglobin decrease of 3.08±1.08g/dL, requiring a transfusion in 12% of the cases. Three medical complications have been registered in the meantime of the admission, with a relevant case of a confusional syndrome and a fall, which resulted in a non-displaced AG1 periprosthetic fracture. The analysis of the positioning of registered implants with Mako® system shows 40.55±1.53 acetabular inclination degrees and 12.2±3.6 acetabular anteversion degrees. The postoperative image study carried out on patients, are consistent with Mako® s results, as it shows an acetabular inclination of 41.2±1.7 in Rx, as well as acetabular anteversion of 16±4.6 in CT. Hip length variance ranges depending on preoperative values of 3.91mm (SD: 3.9; min -12, max 3) to 1.29mm (SD: 1.96) after surgery registered with Mako®, with an increase of an average hip length of 5.64mm (SD: 3.35). Rx simple study results show a postoperative difference between both hips of 0.5±3.08mm, which is consistent with Mako® results. Native femoral offset was stable after surgery with a showing difference both pre and post operative of the intervened hip of 0.1mm (SD: 3.7), registered with Mako®. Preoperatory modified Harris punctuation was 41.6±13.3, improving to postoperative values of 74.6±9.7 after four months since the surgery. No complications were registered in immediate postoperative (4month).

CONCLUSIONS

Total hip arthroplasty robot-assisted achieves an adequate precision and repeatability of the implant positioning and the postoperative hip dysmetry without showing an increase of associated complications to the technique applied. Surgery time, complications and functional results in a short-time period are similar to conventional techniques applied to great series previously published.

Patient satisfaction following robotic unicompartmental knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Unicompartmental knee arthroplasty (UKA) is a viable alternative to total knee arthroplasty (TKA) for osteoarthritis patients with single-compartment involvement, with advantages including accelerated recovery, reduced pain, and improved function. Robotic-assisted UKA (rUKA) is a promising development that ensures precise implant positioning and limb alignment. However, concerns about complications remain.

OBJECTIVE

This study looks at patient satisfaction as a key metric for determining the efficacy of rUKA versus manual UKA (mUKA).

METHODS

The search strategy for this study followed PRISMA. Using precise keywords, PubMed, Scopus, Web of Science, and the Cochrane library were searched. English articles were searched until August 2, 2023. Selection criteria included mUKA and rUKA patient satisfaction studies. The NOS scale evaluated study quality. Meta-analysis was done with R and heterogeneity analysis.

RESULTS

This systematic review examined 5 studies with 1060 UKAs (532 robotic-assisted and 528 manual). Variable satisfaction assessment methods were used. Three studies found no difference in patient satisfaction after robotic-assisted UKA, but two found a higher satisfaction. Meta-analysis showed robotic-assisted UKA improved patient satisfaction (OR = 1.72 [1.25-2.37]). Overall, most studies showed low risk of bias, except one with higher bias.

CONCLUSION

This review suggests that robotic assistance may enhance patient satisfaction in UKA procedures.

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 review of robotic-assisted total hip arthroplasty

Total hip arthroplasty (THA) is a successful surgical method for hip replacement but still poses challenges and risks. Robotic-assisted THA (rTHA) using new generation robotic systems has emerged to improve surgical precision and outcomes. The purpose of this paper is to review the literature on rTHA, with a focus on its advantages, such as individualized preoperative planning, intraoperative assistance, and improved accuracy in implantation, especially in complex cases. Additionally, it aims to explore the disadvantages associated with the use of rTHA, including high costs, the learning curve, and prolonged operation time compared to manual THA (mTHA), which are critical drawbacks that require careful consideration and efforts for minimization. Some financial analyses suggest that rTHA may offer cost-effectiveness and reduced postoperative costs compared to mTHA. While technological advancements are expected to reduce technical complications, there are still debates surrounding long-term outcomes. Practical limitations, such as limited availability and accessibility, also warrant attention. Although the development of rTHA shows promise, it is still in its early stages, necessitating critical evaluation and further research to ensure optimal patient benefits.

Cost-effectiveness of a novel, fluoroscopy-based robotic-assisted total hip arthroplasty system: A Markov analysis

BACKGROUND

The purpose of this study was to assess the cost-effectiveness of a novel, fluoroscopy-based robotic-assisted total hip arthroplasty (RA-THA) system compared to a manual unassisted technique (mTHA) up to 5 years post-operatively.

METHODS

A Markov model was constructed to compare the cost-effectiveness of RA-THA and mTHA. Cost-effectiveness was defined as an Incremental Cost-Effectiveness Ratio (ICER) <$50 000 or $100 000 per Quality Adjusted Life Year (QALY).

RESULTS

RA-THA patients experienced lower costs compared to mTHA patients at 1 year ($20 865.12 ± 9897.52 vs. $21 660.86 ± 9909.15; p < 0.001) and 5 years ($23 124.57 ± 10 045.48 vs. $25 756.42 ± 10 091.84; p < 0.001) post-operatively. RA-THA patients also accrued more QALYs (1-year: 0.901 ± 0.117 vs. 0.888 ± 0.114; p < 0.001; 5-years: 4.455 ± 0.563 vs. 4.384 ± 0.537 p < 0.001). Overall, RA-THA was cost-effective (1-year ICER: $-61 210.77; 5-year ICER: $-37 068.31).

CONCLUSIONS

The novel, fluoroscopy-based RA-THA system demonstrated cost-effectiveness when compared to manual unassisted THA.

Perioperative safety and efficacy of robot-assisted total hip arthroplasty in ERAS-managed patients: a pilot study

AIMS

Robot-assisted total hip arthroplasty (rTHA) boasts superior accuracy in implant placement, but there is a lack of effective assessment in perioperative management in the context of enhanced recovery after surgery (ERAS). This study aimed to compare the effectiveness and safety of rTHA versus conventional total hip arthroplasty (cTHA) in ERAS-managed patients.

METHODS

In this prospective trial, a total of 60 eligible patients aged between 18 and 80 years were randomly divided into two groups to undergo either rTHA or cTHA. The primary outcomes included blood loss parameters. Secondary outcomes were the duration of the operation, surgical time, WOMAC pain score, WOMAC stiffness score, WOMAC physical function score, Harris score, and postoperative complications.

RESULTS

The study cohort analyzed 59 eligible participants, 30 of whom underwent rTHA and 29 of whom underwent cTHA. Analysis could not be conducted for one patient due to severe anemia. Notably, the cTHA group had a significantly shorter surgical time than the rTHA group (69.49 ± 18.97 vs. 104.20 ± 19.63 min, P < 0.001). No significant differences were observed between the rTHA and cTHA groups for blood loss parameters, including total blood loss (1280.30 ± 404.01 vs. 1094.86 ± 494.39 ml, P = 0.137) and drainage volume (154.35 ± 121.50 vs. 159.13 ± 135.04 ml, P = 0.900), as well as intraoperative blood loss (126.67 ± 38.80 vs. 118.52 ± 60.68 ml, P = 0.544) and hidden blood loss (982.43 ± 438.83 vs. 784.00 ± 580.96 ml, P = 0.206). Only one patient in the cTHA group required allogeneic blood transfusion. At 3 months postoperatively, both groups showed improvements in WOMAC pain score, WOMAC stiffness score, WOMAC physical function score, and Harris score, with no significant differences found between the two groups. Few complications were reported in both groups without significant differences.

CONCLUSIONS

Despite the longer surgical time, rTHA did not negatively affect blood loss, pain, or functional recovery or lead to an increased risk of complications in ERAS-managed patients, suggesting that rTHA can be safely and effectively incorporated into an ERAS program for primary THA.

Clinical outcomes of robotic-assisted and manual total hip arthroplasty in the same patient: A case report

BACKGROUND

Total hip arthroplasty (THA) is an effective treatment for advanced osteonecrosis of the femoral head, which can significantly relieve pain and improve patients' quality of life. Robotic-assisted THA enhances the accuracy and stability of THA surgery and achieves better clinical outcomes than manual THA.

CASE SUMMARY

We report the clinical outcomes of robotic-assisted THA and manual THA in the same patient with osteonecrosis of the femoral head. A 49-year-old male patient attended our hospital due to more than 3 years of pain in both hip joints. The left hip was treated with robotic-assisted THA. The patient underwent manual THA of the right hip 3 mo after robotic-assisted THA. We obtained postoperative radiograph parameters, Harris hip score and forgotten joint score of the patient 1 year after surgery.

CONCLUSION

Compared with manual THA, the patient's left hip felt better 1 year after robotic-assisted THA. Robotic-assisted THA resulted in a better Harris hip score and forgotten joint score than manual THA in the same patient with osteonecrosis of the femoral head.

"Incidence of Instability Following Primary Total Hip Arthroplasty Continues to Decline in the Medicare Population"

BACKGROUND

Instability has been the primary cause of failure following primary total hip arthroplasty (THA) leading to revision hip surgery. The purpose of this study was to determine if instability rates have further declined following advances in primary THA including dual mobility articulations, direct anterior approaches, advanced technologies, and improved knowledge of the hip-spine relationships.

METHODS

Using the 5% Medicare Part B claims data from 1999 to 2019, we identified 81,573 patients who underwent primary THA for osteoarthritis. Patients who experienced instability at 3 months, 6 months, 1 year, and 2 years were identified. Multivariate cox regression analyses evaluated the effect of patient and procedure characteristics on the risk for instability.

RESULTS

Instability at 1 year following primary THA declined from approximately 4% in 2000 to 2.3% in 2010 and 1.6% in 2018. The leading cause of revision surgery was infection (18.6%), followed by peri-prosthetic fracture (14%), mechanical loosening (11.5%), and instability (9.4%). High risk groups for instability continue to include increased age, higher Charlson index, obesity, lumbar spine pathology, and neurocognitive disorders.

CONCLUSION

Instability is no longer the leading etiology of failure following primary THA with a decline of approximately 40% over the past decade. Infection, periprosthetic fracture, mechanical loosening, and then instability are now the leading causes of failure. Multiple factors may play a role in the decline of instability including increased use of dual mobility articulations, direct anterior approaches, improved knowledge of the hip-spine relationships, and use of advanced technologies.

Global research status and trends in orthopaedic surgical robotics: a bibliometric and visualisation analysis study

This study aimed to investigate and summarise the current state of research and trends in orthopaedic surgical robots. Data on publicly available publications related to orthopaedic surgical robots were extracted by abstract searches of the Web of Science Core Collection database. A bibliometric analysis and detailed reading of the publications were then carried out and the information was visualised using co-authorship analysis, coupling analysis, co-citation analysis and co-occurrence analysis in VOSviewer. With 436 publications included in the study from 1993 to 2022, the overall contribution of publications to the world showed an increasing trend year by year, with a particularly pronounced after 2017, and a geographical trend of predominantly East Asia, North America, and Western Europe. Of these, China was the largest contributor (n = 128). Overall, the UK affiliates and their scholars were leaders in the field, with a high number of publications, total citations, average citations per article and H-index. The most published institutions and authors were Imperial College London (n = 21) and Professor Fares Sahi Haddad of University College London (n = 12), respectively. Journals with a high overall impact on robotic orthopaedic surgery were the Journal of Arthroplasty, Bone Joint Journal, International Journal of Medical Robotics and Computer Assisted Surgery. Keyword co-occurrence network analysis revealed four main clusters: robot-assisted knee, hip arthroplasty, spine surgery, and robotic technology research and development. The top three most common sites for robot-assisted surgery use were the knee, hip and spine. The most used robot types were the knee and spine, with Mako and Arobot being the most used robots for the knee and TiRobot for the spine. This study comprehensively reveals the current status and trends of global research on orthopaedic surgical robots, covering countries, institutions, authors, journals, research hotspots, robot types and surgical sites, providing directional guidance and research ideas for further research on the technological development and clinical evaluation of orthopaedic surgical robots.

Revision Total Hip Arthroplasty with Severe Acetabular Defect: A Preliminary Exploration and Attempt of Robotic-Assisted Technology

Background

Robotic‐assisted technology may be useful in hip revision cases with acetabular defects. However, data on the use of robotic‐assisted technology for such complex diseases is lacking.

Case Presentation

This case study described the adoption of MAKO robotic‐assisted treatment of revision total hip arthroplasty (THA) combined with severe acetabular defect (Paprosky type IIIB). Robotic‐assisted technology accurately achieved preoperative planning; the acetabular component and augment were placed in the original position and angle as planned. Robotic‐assisted acetabular reaming was successful in a single pass, preserving the remaining acetabular bone mass very well with no procedure‐related complications. The Harris Hip Score (HHS) at 6 months postoperatively was 84 and the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index was 24.

Conclusion

Robotic‐assisted technology can help in the accurate reconstruction of acetabular defect in complex hip revision surgery.

Current Trends in Revision Hip Arthroplasty: Indications and Types of Components Revised

BACKGROUND

The materials and techniques for both primary and revision total hip arthroplasty (THA) have changed over time. This study evaluated if the indications for revision THA, rates of components utilized (femoral or acetabulum, both, or head/liner exchange), length of stay (LOS), and payments to surgeons and facilities have also changed.

METHODS

A retrospective study, utilizing the PearlDiver database, of 38,377 revision THA patients from January 2010 through December 2018 was performed. Data included the indication for revision, components revised (femoral or acetabulum, both, or head/liner exchange), LOS, and payments. Indications and components were analyzed by logistic regression (Dunnett's post hoc test). Revision totals were analyzed with a linear regression model. Analysis of variance assessed changes in LOS and payments.

RESULTS

Patients' median age was 67 years (Q1-Q3: 59-74), and 58.7% were female. Revisions for dislocation decreased between 2010 and 2018 (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.68-0.98). Revisions for component loosening increased (OR 1.54, 95% CI 1.25-1.91). Dislocation remained the most common indication (19.3%), followed by PJI (17.3%) and loosening (17.1%). Both-component (OR:1.45; 95% CI:1.25-1.67) and femoral component only revisions increased; acetabular component only and head/liner exchanges decreased. Acetabular (OR 0.57, 95% CI 0.47-0.70) and head/liner exchange (OR 0.29, 95% CI 0.20-0.43) revisions decreased, while both component exchange (OR 1.45, 95% CI 1.25-1.67) and femoral revisions (OR 1.17, 95% CI 0.99-1.37) increased. Average LOS (-0.68 days; P < .001) and surgeon payments decreased (-$261.8; P < .001) while facility payments increased ($4,211; P < .001).

CONCLUSION

Indications for revision THA in this database study changed over time, with revision for dislocation decreasing and revision for loosening increasing over time. Both component and femoral revisions increased, and acetabular component and head/liner exchanges decreased. It is possible that these associations could be attributed to a number of details, the method of femoral fixation, surgical approach, and cementing, all of which require additional 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.

[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.

Does robotic-assisted computer navigation improve acetabular cup positioning in total hip arthroplasty for Crowe III/IV hip dysplasia? A propensity score case-match analysis

AIMS

Total hip arthroplasty (THA) in patients with hip-dislocation dysplasia remains challenging. This study aims to evaluate whether these patients may benefit from robotic-assisted techniques.

METHODS

We reviewed 135 THAs (108 conventional THAs and 27 robotic-assisted THAs) for Crowe type III or IV from January 2017 to August 2019 in our institution. Robotic-assisted THAs were matched with conventional THAs at a 1:1 ratio (27 hips each group) using propensity score matching. The accuracy of cup positioning and clinical outcomes were compared between groups.

RESULTS

The inclination of the cup for conventional THAs and robotic THAs was 42.1 ± 5.7 and 41.3 ± 4.6 (p = 0.574), respectively. The anteversion of the cup for conventional THAs was significantly greater than that of robotic THAs (29.5 ± 8.1 and 18.0 ± 4.6; p < 0.001), respectively. The ratio of the acetabular cup in the Lewinnek safe zone was 37% (10/27) in conventional THAs and 96.3% (26/27) in robotic THAs (p < 0.001). Robotic THAs did not achieve better leg length discrepancy than that of conventional THAs (- 0.4 ± 10.9 mm vs. 0.4 ± 8.8 mm, p = 0.774). There was no difference in Harris Hip Score and WOMAC Osteoarthritis index between groups at the 2-year follow-up. No dislocation occurred in all cases at the final follow-up.

CONCLUSION

Robotic-assisted THA for patients with high dislocation improves the accuracy of the implantation of the acetabular component with respect to safe zone.

Clinical application of robotic orthopedic surgery: a bibliometric study

Objectives

The present study aimed to evaluate the status and trends of robotic orthopedic surgery in a clinical setting using bibliometrics.

Methods

All relevant publications on the clinical use of robotic surgery in orthopedics were searched from the Web of Science database. Subsequently, data were analyzed using bibliometrics. Visualizing data of bibliographic coupling, co-citation, and co-occurrence analysis were performed using VOSviewer.

Results

In total, 224 clinical studies met the included standards between 2000 to 2019. Global publications presented an increasing annual trend, with the United States found to have the largest number of publications and robotic companies active in the field (n = 99), followed by China (n = 38), and the United Kingdom (n = 27). The institution with the most contributions was the Beijing Jishuitan Hospital in China (n = 15). The most productive scholars were Tian Wei and Mont Michael A, with 14 publications each. The top 30 most cited papers list showed 29 publications to be cited on more than 40 occassions. The journal with the most related and influential publications on robotic orthopedic surgery was the Journal of Arthroplasty. Fourteen types of robots were used, with the majority applied in knee and spinal surgery. MAKO was the most widely used robot in hip and knee surgery and Mazor in spinal surgery. Most studies were small sample populations of low-quality in this field. The top 20 most frequently used keywords were identified from 950 author keywords. Research on orthopedic robots were classified into two clusters by co-occurrence networks: spinal-related robotic surgery and joint-related robotic surgery.

Conclusions

The present bibliometric study summarizes the clinical research of orthopedic robots on study type, sample size, type of surgery, robot information, surgical site, most popular keywords, most cited papers, journals, authors, institutions, and countries. These findings may assist the scholars better understand the current status and research trends to guide future practice and directions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04714-7.

Modern Suture Anchor Techniques for Gluteus Medius Tear Repair With Concomitant Total Hip Arthroplasty Using the Direct Anterior and Posterior Approaches

Gluteus medius (GM) tears are currently a well-established source of pain and disability. However, their role in primary total hip arthroplasty (THA) in the setting of osteoarthritis (OA) has been underexamined in the literature. The purpose of this study was to report on short-term patient-reported outcome measurements (PROMs) for patients who underwent concomitant primary THA and GM repair. Data were prospectively collected from September 2011 and June 2017. Inclusion criteria were primary THA along with concomitant GM repair and complete follow-up for the Harris Hip Score, Forgotten Joint Score 12, Veterans RAND 12-item Health Survey both Physical and Mental, 12-item Short Form Survey both Physical and Mental (SF-12 P and SF-12 M), visual analog scale for pain, and patient satisfaction. Patients were excluded if they did not have follow-up. Thirty patients (30 hips) were included. Mean follow-up was 24.2±19.3 months. Twenty-nine (96.7%) patients were female. Mean age was 65.2±7.4 years. Mean body mass index was 31.1±5.9 kg/m². The posterior approach was used for 16 (53.3%) cases and the anterior approach for the remaining 14 (46.7%). Two (6.7%) patients had a less than 25% tear, 7 (23.3%) had a 25% to 50% tear, 14 (46.7%) had a greater than 50% tear, and 7 (23.3%) had a full-thickness tear. All PROMs except SF-12 M demonstrated significant improvement at latest follow-up. Patients who underwent THA with either the anterior or the posterior approach with concomitant GM repair using modern suture anchor techniques reported favorable PROMs at short-term follow-up. [Orthopedics. 2021;44(5):e653-e660.].

Robotic-assisted total hip arthroplasty: an economic analysis

Aim: To evaluate 90-day episode-of-care (EOC) resource consumption in robotic-assisted total hip arthroplasty (RATHA) versus manual total hip arthroplasty (mTHA). Methods: THA procedures were identified in Medicare 100% data. After propensity score matching 1:5, 938 RATHA and 4,670 mTHA cases were included. 90-day EOC cost, index costs, length of stay and post-index rehabilitation utilization were assessed. Results: RATHA patients were significantly less likely to have post-index inpatient rehabilitation or skilled nursing facility admissions and used fewer home health agency visits, compared with mTHA patients. Total 90-day EOC costs for RATHA patients were found to be US$785 less than those of mTHA patients (p = 0.0095). Conclusion: RATHA was associated with an overall lower 90-day EOC cost when compared with mTHA. The savings associated with RATHA were driven by reduced utilization and cost of post-index rehabilitation services.

Efficacy of da Vinci robot-assisted lymph node surgery than conventional axillary lymph node dissection in breast cancer - A comparative study

BACKGROUND

da Vinci robot-assisted axillary lymph node dissection (dVALND) can be a minimally invasive technique to minimize post-operative complications.

OBJECTIVE

To explore the clinical efficacy of dVALND in breast cancer (BC) patients for mitigating the postoperative complications than conventional ALND.

METHODS

Total 60 female patients with BC were admitted to our hospitals since September 2018, and these patients segregated into two groups of 30 patients each. Modified radical mastectomy for BC was performed to the patients in both groups. In Group 1 (control group), ALND was performed using conventional mode of axillary lymph node surgery. In Group 2 (Test group), the dVALND was performed using da Vinci robot-assisted surgery. Wound healing, aesthetic effect and patient's satisfaction were evaluated after conventional method and dVALND.

RESULTS

Postoperative complications viz., wound infection (1/30 (3.33%), p < 0.05), fat necrosis (3/30 (10%), p < 0.05) and lymphedema of upper limbs (2/30 (6.67%), p < 0.05) were observed in dVALND than conventional surgery. Local recurrence or metastasis was minimized and overall aesthetic effect not observed during follow-up.

CONCLUSION

dVALND improved the overall patient's quality of life by mitigating postoperative complications than ALND.

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.].

Short-term Clinical Outcomes of Robotic-Arm Assisted Total Hip Arthroplasty: A Pair-Matched Controlled Study

Advances have made robotic assistance a viable option in total hip arthroplasty (THA). However, the clinical outcomes of this procedure relative to manual THA are limited in the literature. This study compared robotic-arm assisted (RAA) THA and manual THA at minimum 2-year follow-up. Data were collected prospectively on all THAs performed from July 2011 to January 2015. Patients were included if they underwent RAA primary THA for idiopathic osteo-arthritis and had minimum follow-up of 2 years. The following patient-reported outcomes were compared: Harris Hip Score (HHS), Forgotten Joint Score (FJS-12), visual analog scale (VAS) pain score, and satisfaction. Postoperative radio-graphs were analyzed for cup inclination, cup version, leg-length discrepancy, and global offset. Robotic-arm assisted THA patients were matched 1:1 with manual THA patients for age, sex, body mass index, and surgical approach. Each study group included 85 patients. There were no significant differences in the demographic factors between the groups. Both HHS and FJS-12 were significantly higher in the RAA group at minimum 2-year follow-up. The VAS score was lower in the RAA group, but this difference was not statistically significant. A significantly higher proportion of patients were in the Lewinnek and Callanan safe zones for cup orientation. There was no difference between the groups in patient satisfaction. Robotic-arm assisted THA yielded improved short-term patient outcomes compared with manual THA and higher likelihood of cup placement in the safe zones. No differences were found regarding VAS scores, patient satisfaction, complication rates, or subsequent revisions between groups. [Orthopedics. 2021;44(2):e236-e242.].

Robotic arm-assisted versus manual total hip arthroplasty : a systematic review and meta-analysis

AIMS

The aims of this systematic review were to assess the learning curve of semi-active robotic arm-assisted total hip arthroplasty (rTHA), and to compare the accuracy, patient-reported functional outcomes, complications, and survivorship between rTHA and manual total hip arthroplasty (mTHA).

METHODS

Searches of PubMed, Medline, and Google Scholar were performed in April 2020 in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Search terms included "robotic", "hip", and "arthroplasty". The criteria for inclusion were published clinical research articles reporting the learning curve for rTHA (robotic arm-assisted only) and those comparing the implantation accuracy, functional outcomes, survivorship, or complications with mTHA.

RESULTS

There were 501 articles initially identified from databases and references. Following full text screening, 17 articles that satisfied the inclusion criteria were included. Four studies reported the learning curve of rTHA, 13 studies reported on implant positioning, five on functional outcomes, ten on complications, and four on survivorship. The meta-analysis showed a significantly greater number of cases of acetabular component placement in the safe zone compared with the mTHA group (95% confidence interval (CI) 4.10 to 7.94; p < 0.001) and that rTHA resulted in a significantly better Harris Hip Score compared to mTHA in the short- to mid-term follow-up (95% CI 0.46 to 5.64; p = 0.020). However, there was no difference in infection rates, dislocation rates, overall complication rates, and survival rates at short-term follow-up.

CONCLUSION

The learning curve of rTHA was between 12 and 35 cases, which was dependent on the assessment goal, such as operating time, accuracy, and team working. Robotic arm-assisted total hip arthroplasty was associated with improved accuracy of component positioning and functional outcome, however no difference in complication rates or survival were observed at short- to mid-term follow-up. Overall, there remains an absence of high-quality level I evidence and cost analysis comparing rTHA and mTHA. Cite this article: Bone Joint J 2021;103-B(6):1009-1020.

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.

The Impact of Author Financial Conflicts on Robotic-Assisted Joint Arthroplasty Research

BACKGROUND

Recent studies have suggested clinical superiority with robotic-assisted arthroplasty compared to traditional techniques. However, concerns exist regarding the author's financial conflicts of interest (COI), which may influence research outcomes. This study aimed to determine whether COI relating to robotic-assisted arthroplasty influences the results of published outcomes following total hip (THA), total knee (TKA), and unicompartmental knee arthroplasty (UKA).

METHODS

We performed a systematic review to identify all studies evaluating the use of robotics in THA, TKA, and UKA. An author's financial COI was identified if they reported a relevant disclosure through the American Academy of Orthopedic Surgeons or within the study article. We then queried the Open Payments website to record all payments made from a robotic company in the year prior to publication. Each study was categorized as either favoring robotics (n = 42), neutral (n = 10), or favoring traditional techniques (n = 2). We then compared the number of conflicted authors, journal impact factor, level of evidence, and mean annual industry payment to each author.

RESULTS

Of the 54 studies meeting inclusion criteria, 49 (91%) had an author financial COI. Conflicted studies were more likely to report favorable results of robotics than nonconflicted studies. When compared to studies favoring conventional techniques, those demonstrating favorable robotics outcomes had a higher number of conflicted authors and a higher mean industry payment per author. There was no difference in the level of evidence or journal impact factor.

DISCUSSION

Nearly all studies comparing robotic THA, TKA, and UKA to conventional techniques involve financially conflicted authors. Further studies without COI may provide unbiased results.

Early postoperative clinical recovery of robotic arm-assisted vs. image-based navigated Total hip Arthroplasty

BACKGROUND

This study compared the early clinical recovery of total hip arthroplasty (THA) using computer navigation systems (nTHA) and robotic arm-assisted THA (rTHA).

METHODS

Thirty prospective subjects who underwent rTHA were clinically compared to 30 subjects who underwent nTHA. Clinical data (surgical time, intraoperative blood loss, pain severity, number of days to independent walking, and Harris Hip Score (HHS) at discharge), and radiographic parameters (inclination and anteversion angles) were statistically compared between the two groups.

RESULTS

Follow-up times were 24.3 ± 6.0 and 27.0 ± 7.0 days in the rTHA and nTHA groups, respectively. The surgical time (135.1 ± 13.9 min vs. 146.2 ± 12.8 min, p = 0.002), number of days to independent walking (7.2 ± 2.0 vs. 11.5 ± 3.0 days, p < 0.001), and postoperative pain using a numeric rating scale on postoperative days 7, 10,, and 14 (1.4 ± 0.9 vs. 2.2 ± 1.2, p = 0.005; 1.0 ± 0.8 vs. 1.8 ± 1.1, p = 0.002; 0.3 ± 0.5 vs. 1.1 ± 0.9, p < 0.001; respectively) were significantly reduced in the rTHA group compared to the nTHA group. The rTHA group showed a significantly higher postoperative HHS compared to the nTHA group (85.3 ± .3.2 vs. 81.0 ± 8.5, p = 0.014). No statistically significant difference was observed in radiographic parameters between the groups; however, the incidence of intraoperative target angle changes was significantly lower in the rTHA group than in the nTHA group (0/30 subjects [0%] vs. 11/30 subjects [36.7%], p < 0.001).

CONCLUSION

The surgical time, postoperative pain, and number of days to independent walking were significantly shorter, and the HHS at discharge was significantly higher in the rTHA group than in the nTHA group. Thus, compared to the nTHA group, the rTHA group showed improved early clinical recovery.

Robotic arm-assisted versus manual total hip arthroplasty

AIMS

The primary aim of this study was to compare the hip-specific functional outcome of robotic assisted total hip arthroplasty (rTHA) with manual total hip arthroplasty (mTHA) in patients with osteoarthritis (OA). Secondary aims were to compare general health improvement, patient satisfaction, and radiological component position and restoration of leg length between rTHA and mTHA.

METHODS

A total of 40 patients undergoing rTHA were propensity score matched to 80 patients undergoing mTHA for OA. Patients were matched for age, sex, and preoperative function. The Oxford Hip Score (OHS), Forgotten Joint Score (FJS), and EuroQol five-dimension questionnaire (EQ-5D) were collected pre- and postoperatively (mean 10 months (SD 2.2) in rTHA group and 12 months (SD 0.3) in mTHA group). In addition, patient satisfaction was collected postoperatively. Component accuracy was assessed using Lewinnek and Callanan safe zones, and restoration of leg length were assessed radiologically.

RESULTS

There were no significant differences in the preoperative demographics (p ≥ 0.781) or function (p ≥ 0.383) between the groups. The postoperative OHS (difference 2.5, 95% confidence interval (CI) 0.1 to 4.8; p = 0.038) and FJS (difference 21.1, 95% CI 10.7 to 31.5; p < 0.001) were significantly greater in the rTHA group when compared with the mTHA group. However, only the FJS was clinically significantly greater. There was no difference in the postoperative EQ-5D (difference 0.017, 95% CI -0.042 to 0.077; p = 0.562) between the two groups. No patients were dissatisfied in the rTHA group whereas six were dissatisfied in the mTHA group, but this was not significant (p = 0.176). rTHA was associated with an overall greater rate of component positioning in a safe zone (p ≤ 0.003) and restoration of leg length (p < 0.001).

CONCLUSION

Patients undergoing rTHA had a greater hip-specific functional outcome when compared to mTHA, which may be related to improved component positioning and restoration of leg length. However, there was no difference in their postoperative generic health or rate of satisfaction. Cite this article: Bone Joint Res 2021;10(1):22-30.

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

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.

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

Background

As robot-assisted equipment is continuously being used in orthopaedic surgery, the past few decades have seen an increase in the usage of robotics for total knee arthroplasty (TKA). Thus, the purpose of the present study is to investigate the differences between robotic TKA and nonrobotic TKA on perioperative and postoperative complications and opioid consumption.

Methods

An administrative database was queried from 2010 to Q2 of 2017 for primary TKAs performed via robot-assisted surgery vs non-robot-assisted surgery. Systemic and joint complications and average morphine milligram equivalents were collected and compared with statistical analysis.

Results

Patients in the nonrobotic TKA cohort had higher levels of prosthetic revision at 1-year after discharge (P < .05) and higher levels of manipulation under anesthesia at 90 days and 1-year after discharge (P < .05). Furthermore, those in the nonrobotic TKA cohort had increased occurrences of deep vein thrombosis, altered mental status, pulmonary embolism, anemia, acute renal failure, cerebrovascular event, pneumonia, respiratory failure, and urinary tract infection during the inpatient hospital stay (all P < .05) and at 90 days after discharge (all P < .05). All of these categories remained statistically increased at the 90-days postdischarge date, except pneumonia and stroke. Patients in the nonrobotic TKA cohort had higher levels of average morphine milligram equivalents consumption at all time periods measured (P < .001).

Conclusions

In the present study, the use of robotics for TKA found lower revision rates, lower incidences of manipulation under anesthesia, decreased occurrence of systemic complications, and lower opiate consumption for postoperative pain management. Future studies should look to further examine the long-term outcomes for patients undergoing robot-assisted TKA.

Level of Evidence

Level III.

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.

Use of Robotic-Arm Assisted Technique in Complex Primary Total Hip Arthroplasty

Background

There is a lack of data concerning the use of robotic devices in more complex total hip arthroplasty (THA) cases, such as hip dysplasia, ankylosing spondylolysis, and post‐traumatic arthritis.

Case Presentation

This case study presented three cases in which the Mako robotic device was used to help accurately implement the surgical plan. The operations went smoothly. The position and angle of the acetabular shells were placed as planned without any complications related to the operation. Postoperative Harris Hip Scores were good in two patients and poor in the patient with ankylosing spondylitis. Robotic‐arm assisted surgery may be considered for complex THA cases in order to optimize the accuracy of the reconstruction, especially in the absence of conventional boney landmarks.

Current topics in robotic-assisted total hip arthroplasty: a review

Total hip arthroplasty (THA) is among the most successful procedures of modern medicine, yet failures and complications continue to occur, leaving room for improvement. Robotics is a cutting-edge technology that tries to improve joint arthroplasty surgery. There is some evidence that shows that robotic-assisted THA improves implant positioning, but less is known about its effect on clinical outcomes or the rate of complications. This article reviews the literature on robotic-assisted THA to elucidate the history, advantages, disadvantages, and current clinical understanding of this procedure.

Expanding Robotic Arm-Assisted Knee Surgery: The First Attempt to Use the System for Knee Revision Arthroplasty

Robotic arm-assisted arthroplasty was introduced in 2006 and has expanded its applications into unicompartmental knee, total knee, and total hip replacement. The first case of a revision surgery from conventional unicompartmental to total knee arthroplasty with the utilization of the robotic arm-assisted MAKO system is presented. An 87-year-old female presented with deteriorating left knee pain due to failure of medial unicompartmental knee arthroplasty at the outpatient clinic. The patient was advised to undergo revision surgery. Through medial parapatellar arthrotomy, the joint was exposed. With the use of the MAKO system, the estimated depth of the medial plateau according to CT planning was found to be 10 mm more distal than the lateral. The resection line of the remaining plateau was placed deliberately 2 mm more distal in order to achieve satisfactory replacement of the bony gap of the medial tibial condyle by a 10 mm augment. The patient had an uneventful recovery. A plethora of additional applications in the future, such as total shoulder or reverse total shoulder arthroplasty, megaprosthesis placement in oncological patients, and total hip or knee revision surgeries, may improve patient-related outcomes.

The current role of robotics in total hip arthroplasty

Robotic total hip arthroplasty (THA) improves accuracy in achieving the planned acetabular cup positioning compared to conventional manual THA.

Robotic THA improves precision and reduces outliers in restoring the planned centre of hip rotation compared to conventional manual THA.

Improved accuracy in restoring hip biomechanics and acetabular cup positioning in robotic THA have not translated to any differences in early functional outcomes, correction of leg-length discrepancy, or postoperative complications compared to conventional manual THA.

Limitations of robotic THA include substantive installation costs, additional radiation exposure, steep learning curves for gaining surgical proficiency, and compatibility of the robotic technology with a limited number of implant designs.

Further higher quality studies are required to compare differences in conventional versus robotic THA in relation to long-term functional outcomes, implant survivorship, time to revision surgery, and cost-effectiveness.

Cite this article: EFORT Open Rev 2019;4:618-625. DOI: 10.1302/2058-5241.4.180088

Causes of and treatment options for dislocation following total hip arthroplasty

The second most common complication following total hip arthroplasty (THA) is dislocation. The majority of dislocations occur early in the post-operative period and are due to either patient-associated or surgical factors. The patient-associated factors that have been implicated as causes of post-operative dislocation include previous surgery, lumbar spine fusion surgery and/or neurological impairment. The surgical factors include surgical approach, component orientation and prosthetic and/or bony impingement. In order to delineate the cause of the hip instability a thorough history and physical and a radiographic assessment (possibly including advanced imaging) needs to be performed. Approximately two thirds of cases are successfully treated; one third of cases will require surgical treatment (e.g., revision arthroplasty (including constrained liners, the use of elevated rim liners and dual mobility implants or trochanteric advancement). In this review, we discuss the causes leading to dislocation following THA and evaluate the different treatment options available.

Robotics-assisted versus conventional manual approaches for total hip arthroplasty: A systematic review and meta-analysis of comparative studies

Background

Several studies have compared robotics‐assisted (RA) and conventional manual (CM) approaches for total hip arthroplasty (THA), but their results are controversial.

Methods

A literature search was conducted for controlled clinical trials (CCTs) comparing the clinical efficacy of the RA and CM approaches for THA and published between August 1998 and August 2018. The obtained data were analyzed using the statistical software Review Manager 5.3.

Results

Fourteen articles were included in the meta‐analysis, which revealed that the RA group had less intraoperative complications, better cup angle, and more cases of cup placement in the safe zone than the CM group. However, the operation time required for the CM group was less than that required for the RA group. Moreover, postoperative complications (eg, dislocation and revision surgery) were less frequent in the CM group than in the RA group. However, the two groups had similar functional scores, total number of complications, and rate of occurrence of limb length discrepancy.

Conclusion

Compared with the CM approach, the RA approach yields better radiological outcomes and fewer intraoperative complications in THA, but similar functional scores.

Relationship Between PROMIS Computer Adaptive Tests and Legacy Hip Measures Among Patients Presenting to a Tertiary Care Hip Preservation Center

BACKGROUND

Legacy hip outcome measures may be burdensome to patients and sometimes yield floor or ceiling effects. Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive tests (CATs) allow for low-burden data capture and limited ceiling and floor effects.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine whether the PROMIS CAT domains demonstrate correlation against commonly used legacy patient-reported outcome measures in a population of patients presenting to a tertiary care hip preservation center. The authors hypothesized the following: (1) PROMIS CAT scores based on physical function (PF), pain interference (PIF), pain behavior, and pain intensity would show strong correlation with the following legacy scores: modified Harris Hip Score (mHHS), International Hip Outcome Tool-12 (iHOT-12), Hip Outcome Score (HOS) Sports and Activities of Daily Living subscales, and Veterans RAND-6D (VR-6D) utility measure. (2) The mental and physical health portions of the VR-6D legacy measure would show weak correlation with mental- and psychosocial-specific PROMIS elements-depression, anxiety, fatigue, sleep, and ability to participate in social roles and activities. (3) All PROMIS measures would exhibit fewer floor and ceiling effects than legacy scores.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Prospective data were collected on 125 patients in the hip preservation clinics. Enrollees completed legacy scores (visual analog scale for pain, mHHS, iHOT-12, HOS, and VR-6D) and PROMIS CAT questionnaires (PF, PIF, pain behavior, anxiety, depression, sleep, social roles and activities, pain intensity, fatigue). Spearman rank correlations were calculated, with r_s values of 0 to 0.3 indicating negligible correlation; 0.3 to 0.5, weak correlation; 0.5 to 0.7, moderately strong correlation; and >0.7, strong correlation. Floor and ceiling effects were evaluated.

RESULTS

As anticipated, the PF-CAT yielded strong correlations with the iHOT-12, mHHS, HOS-Sports, HOS-Activities of Daily Living, and VR-6D, with r_s values of 0.76, 0.71, 0.81, 0.87, and 0.71, respectively. The PIF-CAT was the only pain score to show moderately strong to strong correlation with all 14 patient-reported outcome measures. A strong correlation was observed between the VR-6D and the social roles and activities CAT ( r_s = 0.73). The depression CAT had a significant floor effect at 19%. No additional floor or ceiling effect was present for any other legacy or PROMIS measure.

CONCLUSION

The PF-CAT shows strong correlation with legacy patient-reported outcome scores among patients presenting to a tertiary care hip preservation center. The PIF-CAT also correlates strongly with legacy and PROMIS measures evaluating physical and mental well-being. PROMIS measures are less burdensome and demonstrate no floor or ceiling effects, making them a potential alternative to legacy patient-reported outcome measures for the hip.