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

Opioid Use After Robotic-Assisted Versus Conventional Total Hip Arthroplasty:A National Database Analysis

BACKGROUND

In this study, we tested the null hypothesis that robotic-assisted total hip arthroplasty (THA) vs conventional THA was not associated with (1) the amount of postoperative opioid use and (2) the incidence of new, persistent opioid use.

MATERIALS AND METHODS

We used a large, national administrative database to identify patients 50 years and older undergoing primary robotic or conventional THA. Patients with hip fractures or a history of malignancy, hip infection, or opioid use disorder were excluded. Patients who filled an opioid prescription within 1 year to 30 days preoperatively or who underwent a subsequent procedure within 1 year after THA were excluded. Outcomes included the morphine milligram equivalents (MMEs) filled within the THA perioperative period and the incidence of new, persistent opioid use. Multivariable logistic regression models were used to evaluate associations between robotic-assisted THA and new, persistent opioid use, adjusting for age, sex, insurance plan, region, location of surgery, and comorbidities.

RESULTS

In the postoperative period, robotic-assisted THA, compared with conventional THA, was associated with a lower mean total MMEs filled per patient (452.2 vs 517.1; P<.001) and a lower mean MMEs per patient per day (71.53 vs 74.64; P<.001). Patients undergoing robotic-assisted THA had decreased odds of developing new, persistent opioid use compared with patients undergoing conventional THA (adjusted odds ratio, 0.82 [95% CI, 0.74-0.90]).

CONCLUSION

Robotic-assisted THA is associated with lower postoperative opioid use and a decreased odds of developing new, persistent opioid use compared with conventional THA. For the purposes of reducing opioid use, our results support the adoption of robotic-assisted THA. [Orthopedics. 202x;4x(x):xx-xx.].

Robotic-assisted Total Hip Arthroplasty and Spinopelvic Parameters: A Review

Total hip arthroplasty (THA) is an effective treatment for osteoarthritis, and the popularity of the direct anterior approach has increased due to more rapid recovery and increased stability. Instability, commonly caused by component malposition, remains a significant concern. The dynamic relationship between the pelvis and lumbar spine, deemed spinopelvic motion, is considered an important factor in stability. Various parameters are used in evaluating spinopelvic motion. Understanding spinopelvic motion is critical, and executing a precise plan for positioning the implant can be difficult with manual instrumentation. Robotic and/or navigation systems have been developed in the effort to enhance THA outcomes and for implementing spinopelvic parameters. These systems can be classified into three categories: X-ray/fluoroscopy-based, imageless, and computed tomography (CT)-based. Each system has advantages and limitations. When using CT-based systems, preoperative CT scans are used to assist with preoperative planning and intraoperative execution, providing feedback on implant position and restoration of hip biomechanics within a functional safe zone developed according to each patient's specific spinopelvic parameters. Several studies have demonstrated the accuracy and reproducibility of robotic systems with regard to implant positioning and leg length discrepancy. Some studies have reported better radiographic and clinical outcomes with use of robotic-assisted THA. However, clinical outcomes comparable to those for manual THA have also been reported. Robotic systems offer advantages in terms of accuracy, precision, and potentially reduced rates of dislocation. Additional research, including conduct of randomized controlled trials, will be required in order to evaluate the long-term outcomes and cost-effectiveness of robotic-assisted THA.

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.

Which way forward? Comparing radiological outcomes using three different surgical approaches in robotic assisted total hip arthroplasty

OBJECTIVES

To assess the accuracy and precision of acetabular component placement in robot-assisted surgery total hip arthroplasty (RAS-THA) using three different approaches.

METHODS

This study is a secondary analysis from a multicenter, randomized controlled trial comparing the Trex RS Hip 1.0 robot navigation system across different surgical approaches. It involved 145 patients treated at three Chinese medical centers from June 2021 to July 2022. Patients with end-stage joint disease were randomly assigned to either the RAS or control group. Acetabular component positioning was evaluated radiographically, and registration accuracy was measured using Root Mean Square Error (RMSE).

RESULTS

The overall RMSE was 0.72 mm (SD = 0.24 mm), indicating consistent accuracy regardless of surgical approach. Significant variations in anteversion were noted across groups (p = 0.001). Lateral RAS-THA showed enhanced precision. The RAS Direct Anterior Approach (DAA) group had the least deviation in the rotation center's horizontal distance (0.89 ± 1.14 mm, p = 0.0014) and minimal leg length discrepancy (2.41 ± 1.17 mm). The RAS DAA approach also produced more consistent results.

CONCLUSION

Robotic assistance in THA, especially via the DAA approach, enhances the accuracy and precision of acetabular component positioning. Consistent registration accuracy across various surgical approaches confirms the reliability of these methods for THA.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov identifier is ChiCTR2100044124.

Use of a fluoroscopy-based robotic-assisted total hip arthroplasty system produced greater improvements in patient-reported outcomes at one year compared to manual, fluoroscopic-assisted technique

INTRODUCTION

The adoption of new technology should be supported by improvements in patient-reported outcomes (PROMs). The purpose of this study was to assess the one-year PROMs of patients who underwent total hip arthroplasty (THA) using a novel, fluoroscopy-based, robotic-assisted (RA-THA) system when compared to a manual, fluoroscopic-assisted technique (mTHA).

MATERIALS AND METHODS

A review of 91 consecutive mTHA and 85 consecutive RA-THA via a direct anterior approach was conducted. All cases were performed by the same surgeon at the same institution, for a pre-operative diagnosis of osteoarthritis, avascular necrosis, or rheumatoid arthritis. Outcomes included one-year Veterans RAND-12 (VR-12) Physical/Mental, Hip Disability and Osteoarthritis Outcome (HOOS) Pain/Physical Function/Joint Replacement, and University of California Los Angeles (UCLA) Activity scores, as well as the difference between pre-operative and one-year post-operative PROMs.

RESULTS

Patients in the RA-THA cohort had lower pre-operative HOOS-JR scores compared to patients in the mTHA cohort (37.0 vs. 43.1; p = 0.031). Cohorts experienced similar one-year post-operative VR-12, HOOS, and UCLA Activity scores. Patients in the RA-THA cohort experienced greater improvements across all pre- and post-operative HOOS scores compared to patients in the mTHA cohort: Pain (+ 54.7 vs. +42.1; p = 0.009), Physical Function (-41.6 vs. -28.7; p = 0.007), and Joint Replacement (+ 46.6 vs. +33.0; p = 0.002). These differences exceeded minimum clinically important difference (MCID).

CONCLUSIONS

Both manual and robotic cohorts experienced benefit from THA at one-year post-operative. Importantly, the use of a novel, fluoroscopy-based robotic assistance system for primary THA resulted in greater improvements in PROMs at one-year relative to manual technique.

Improved short-term outcomes for a novel, fluoroscopy-based robotic-assisted total hip arthroplasty system compared to manual technique with fluoroscopic assistance

BACKGROUND

While robotic-assisted total hip arthroplasty (RA-THA) has been associated with improved accuracy of component placement, the perioperative and early postoperative outcomes of fluoroscopy-based RA-THA systems have yet to be elucidated.

METHODS

This retrospective cohort analysis included a consecutive series of patients who received manual, fluoroscopy-assisted THA (mTHA) and fluoroscopy-based RA-THA at a single institution. We compared rates of complications within 90 days of surgery, length of hospital stay (LOS), and visual analog scale (VAS) pain scores.

RESULTS

No differences existed between groups with respect to demographic data or perioperative recovery protocols. The RA-THA cohort had a significantly greater proportion of outpatient surgeries compared to the mTHA cohort (37.4% vs. 3.8%; p < 0.001) and significantly lower LOS (26.0 vs. 39.5 h; p < 0.001). The RA-THA cohort had a smaller 90-day postoperative complication rate compared to the mTHA cohort (0.9% vs. 6.7%; p = 0.029). The RA-THA cohort had significantly lower patient-reported VAS pain scores at 2-week follow-up visits (2.5 vs. 3.3; p = 0.048), but no difference was seen after 6-week follow visits (2.5 vs. 2.8; p = 0.468).

CONCLUSION

Fluoroscopy-based RA-THA demonstrates low rates of postoperative complications, improved postoperative pain profiles, and shortened LOS when compared to manual, fluoroscopy-assisted THA.

Patient-reported and radiographic outcomes of a porous-coated acetabular cup in robotic assisted total hip arthroplasty at 2-year follow up

Introduction

Several implant manufacturers have developed ultra-porous metal substrate acetabular components recently. Despite this, data on clinical and radiographic outcomes remain limited. Our study evaluated postoperative patient-reported outcome measures (PROMs) and radiographic analyses in patients fitted with a novel acetabular porous-coated component.

Methods

A total of 152 consecutive patients underwent a total hip arthroplasty by a single orthopaedic surgeon. All patients underwent surgery utilizing the same CT-scan based robotic-assisted device with the same porous cementless acetabular shell. They received standardized postoperative physical therapy, rehabilitation, and pain protocols. Preoperatively, first postoperative visit, 6-months, 1-year, and 2-years, patients were evaluated based on Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain, physical function, and total scores; 2) Patient-Reported Outcomes Measurement Information System (PROMIS)-10 physical and mental scores; 3) Hip Disability and Osteoarthritis Outcome Score (HOOS)-Jr scores; as well as 4) acetabular component positions and 5) evidence of acetabular component loosening.

Results

Significant improvements were observed by 6 months in WOMAC pain, physical function, and total scores (p < 0.05), maintained at 1 and 2 years. PROMIS-10 physical scores also improved significantly from preoperative to 6 months postoperative and remained so at 1 and 2 years postoperative (p < 0.05). No significant changes were found in PROMIS-10 mental scores. HOOS-Jr scores significantly improved from preoperative to 6 months postoperative and remained so through 2 years (p < 0.05). At 6 months, slight changes were noted in abduction angle and horizontal and vertical offset. Radiolucencies, initially found in 3 shells, reduced to 1 shell with 2 new radiolucencies by 6 months, and remained stable with no subsequent operative interventions. At 1 year and 2 years, no radiographic abnormalities were noted, including complete resolution of prior radiolucencies as well as stable components.

Conclusion

This porous cementless acetabular shell, implanted with CT-scan-based robotic-assisted techniques, demonstrated excellent postoperative PROMs at 2 years. Stable radiolucencies suggest good component stability. The early stable clinical and radiographic results suggest promising long-term outcomes with this device.

Level of evidence

III (retrospective cohort study).

Improved accuracy and fewer outliers with a novel CT-free robotic THA system in matched-pair analysis with manual THA

Accurate component orientation and restoration of hip biomechanics remains a continuing challenge in total hip arthroplasty (THA). The goal of this study was to analyze the accuracy/reproducibility of a novel CT-free and pin-less robotic-assisted THA (RA-THA) platform compared to manual THA (mTHA). This matched-pair cadaveric study compared this RA-THA system to mTHA (n = 33/arm), both using the assistance of fluoroscopic imaging, in a group of 14 high-volume arthroplasty surgeons. In both groups, surgeons were asked to aim for 40°/15° for cup inclination/version, and 0 mm of leg length discrepancy (LLD). A validated and accurate method using radio-opaque markers measured cup inclination/version and LLD. The accuracy and reproducibility (fewer outliers) of cup inclination was significantly improved in the robotic group (1.8° ± 1.3° vs 6.4° ± 4.9°, respectively, robotic vs manual; p < 0.001), with no significant difference between groups for version. The reproducibility of LLD was significantly improved in the robotic group (p = 0.003). For all parameters studied, the robotic group had an improved accuracy and lower variance (fewer outliers). The percentage of cases within the more restrictive Callanan safe zone was 100% for RA-THA vs 73% for mTHA (p = 0.002). The CT-free RA-THA platform, using only fluoroscopic imaging, demonstrated more accurate acetabular cup positioning, when compared to the mTHA procedures performed by high-volume hip surgeons (naive to this RA-THA platform), with respect to cup inclination and placement within the Lewinnek/Callanan safe zones. Future study must incorporate economic factors, lower volume surgeons, clinical and patient-centric outcomes, and other radiographic parameters in controlled studies in large sample sizes.

[Comparative study of intra- and post-operative inclination and anteversion angles of acetabular cup in robot-assisted total hip arthroplasty]

Objective

To compare the difference in the inclination and anteversion angles of the acetabular cup measured by intraoperative robot-assisted total hip arthroplasty (THA) and postoperative X-ray films and CT imaging.

Methods

The clinical data of 54 patients (54 hips) who underwent robot-assisted THA between May 2020 and December 2020 were retrospectively analyzed. Among them, there were 26 males (26 hips) and 28 females (28 hips), with an average age of 58.4 years (range, 39-71 years). The body mass index was 19.2-29.3 kg/m ², with an average of 25.2 kg/m ². All the patients had their first THA, including 31 cases of osteonecrosis of the femoral head, 12 cases of hip arthritis, 8 cases of femoral neck fracture, and 3 cases of developmental dysplasia of the hip. The anteversion and inclination angles of the acetabular cup were obtained through the surgical data in the robot host system. All patients underwent X-ray and CT scan examination within 2-7 days after operation to obtain the postoperative anteversion and inclination angles of the acetabular cup. According to the concept of "Lewinnek safe zone", the proportion of acetabular in the safe zone intra- and post-operation were compared.

Results

The operation time was 57.8-89.2 minutes, with an average of 68.3 minutes; the intraoperative blood loss was 125.0-450.0 mL, with an average of 204.8 mL. No adverse events such as dislocation of hip joint and infection occurred during hospitalization. The anteversion angle of acetabular cup was (40.8±0.6)° during operation and (41.2±2.8)° after operation, with no significant difference ( t=1.026, P=0.307). The anteversion angle of acetabular cup measured during operation was (17.6±1.4)°, which was significantly smaller than that measured after operation (23.4±3.8)°( t=10.520, P=0.000). According to "Lewinnek safe zone", 54 hips (100%) were in the safety zone during operation, and 16 hips were out of the safety zone, 38 hips were in the safty zone after operation, the ratio of the hips in the safty zone was 70.4%, showing a significant difference ( χ ²=18.783, P=0.000).

Conclusion

Robot-assisted THA can obtain accurate placement of the acetabular cup, but there is a large deviation between the anteversion angle of the acetabular cup in the lateral position during operation and the supine position after operation. Further study is needed to define the intraoperative placement position of the acetabular cup.

[Early effectiveness of robot-assisted total hip arthroplasty via direct superior approach]

Objective

To evaluate the early effectiveness of the robot-assisted total hip arthroplasty (THA) via direct superior approach (DSA).

Methods

Between March 2021 and April 2021, 11 patients (11 hips) were treated with a robot-assisted THA via DSA. There were 7 males and 4 females, with an average age of 55 years (range, 26-73 years). There were 5 patients of osteoarthritis secondary to hip dysplasia and 6 patients of osteonecrosis of femoral head. Preoperative hip Harris score was 55.8±6.3. The operation time, volume of blood loss, length of incision, postoperative blood transfusion and hospital stay, and the incidence of surgical complications were recorded. The visual analogue scale (VAS) score and Harris score were used to evaluate hip joint pain and function. The leg length discrepancy (LLD) was measured on the X-ray films. The inclination angle and anteversion angle of the acetabular component were also measured, and the difference between the planned and actual values were compared.

Results

One THA was performed via conventional posterolateral approach finally because of poor exposure. The rest of 10 THAs were performed with assistance of robotic arm via DSA. The average operation time was 89 minutes (range, 65-120 minutes); the average length of incision was 10.5 cm (range, 9-13 cm); and the average blood loss was 400 mL (range, 110-740 mL). One patient was given a blood transfusion for 2 unit. All incisions healed by first intention and no neurovascular injury, deep vein thrombosis, or fracture occurred. The length of hospital stay after operation was 2-6 days (mean, 4.4 days). The duration of follow-up was 1-3 months (mean, 2.1 months). The VAS score was 0 in 9 patients and 2 in 1 patient at the day of discharge. At last follow-up, the hip Harris score was 84.9±6.7, showing significant difference when compared with that before operation ( t=-8.717, P=0.000). The inclination and anteversion angles were (37.4±2.0)° and (17.1±4.5)°, respectively, and there was no significant difference when compared with the planned values [(38.2±1.6)°, (16.6±3.7)°] ( t=1.809, P=0.104; t=-1.103, P=0.299). The LLD ranged from -2 to 4 mm. No complication such as dislocation, aseptic loosening, or periprosthetic joint infection occurred.

Conclusion

The robot-assisted THA via DSA has encouraged early effectiveness.

[Application of Mako robot-assisted total hip arthroplasty in developmental dysplasia of the hip]

Objective

To evaluate the early effectiveness and summarize the initial application experiences of Mako robot-assisted total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH) in adults.

Methods

Between August 2018 and January 2020, 55 cases of DDH (75 hips) were treated with Mako robot-assisted THA. There were 10 males and 45 females with an average age of 51 years (range, 30-73 years). There were 35 cases of unilateral hip and 20 cases of bilateral hips. The DDH was classified as Crowe type Ⅰin 29 hips, type Ⅱ in 20 hips, type Ⅲ in 6 hips, and type Ⅳ in 20 hips. The modified Harris score was 54.8±16.0, the hip joint range of motion was 90° (80°, 100°), and the leg length discrepancy (LLD) was 22.0 (10.5, 47.0) mm. The preoperative surgical plan was made in the robot system based on the CT data. The reaming and installation of the acetabular cup were completed with the assistance of the robot system. The distance between the rotation center of the hip joint and the teardrop (horizontal distance, vertical distance), inclination angle, and anteversion angle were measured on the pelvic X-ray film to evaluate the position of the acetabular prosthesis. The above indicators were compared with preoperative planning to evaluate the accuracy of robotic-assisted surgery. The modified Harris score, the range of motion, and the LLD were used to evaluate the early effectiveness.

Results

The 75 hips of THAs were completed with the assistance of Mako robots. There was no significant difference in the acetabular inclination angle, the horizontal distance and the vertical distance of the rotation center between the preoperative planning and the postoperative measurement values ( P>0.05); the acetabular anteversion angle was significantly smaller than the postoperative measurement value ( t=-2.482, P=0.015). Four hips located beyond the Lewinnek safety zone, and 71 hips located within the Lewinnek safety zone. All patients followed up 6-24 months (mean, 13 months). All incisions healed by first intention. At last follow-up, the modified Harris score was 85.5±11.2, the hip joint range of motion was 120° (110°, 120°), and the LLD was 3.8 (2.0, 8.1) mm; all improved significantly compared with preoperative ones ( P<0.05). Except for one nerve injury case, there was no other complication.

Conclusion

Mako robot-assisted THA is a safe and effective method for adult DDH, which can optimize the acetabular cup positioning, hip function, and leg length, but the long-term effectiveness needs to be confirmed by further studies.

Comparing early and mid-term outcomes between robotic-arm assisted and manual total hip arthroplasty: a systematic review

The projected increase in utilization rates of total hip arthroplasty (THA) has created an emphasis on novel technologies that can aid providers in maintaining historically positive outcomes. Widespread utilization of robotic assisted THA (RA-THA) is contingent upon achieving favorable outcomes compared to its traditional manual counterpart (mTHA). Therefore, the purpose of our systematic review was to compare RA-THA and mTHA in terms of the following: (1) functional outcomes and (2) complication rates. The PubMed, Embase, and Cochrane library databases were searched for articles published October 1994 and May 2021 comparing functional outcomes and complication rates between RA-THA and mTHA cohorts. When three or more studies evaluated certain PROMs and complications, a pooled analysis utilizing Mantel-Haenszel (M-H) models was conducted utilizing data from final follow-up. Our final analysis included 18 studies which reported on a total of 2811 patients [RA-THA: n = 1194 (42.48%); mTHA: n = 1617 (57.52%)]. No significant differences were demonstrated for a majority of pooled analyses and when segregating by robotic system. Only WOMAC scores were significantly lower among RA-THA patients (p = 0.0006). For outcomes without sufficient data for a pooled analysis, there were no significant differences reported among included studies. The growing utilization of RA-THA motivates comparisons to its manual counterpart. Collectively, we found comparable functional outcomes and complication profiles between RA-THA and mTHA cohorts. More randomized controlled trials of higher quality and larger sample sizes are necessary to further strengthen these findings.