Manual Total Hip Arthroplasty Research Articles

CT Scan-Based Robotic-Arm Assisted Total Hip Arthroplasty: What Do Today's Highest-Quality Studies Tell Us?

Total hip arthroplasty (THA) aims to restore function and reduce pain for patients suffering from hip pathologies. However, some procedures require revision THA, with the most common reasons including: mechanical failure, aseptic loosening, infection, and component malposition leading to dislocations. Computed tomography (CT) scan-based, three-dimensional imaging operating techniques can help address some of these issues by helping to provide more optimal implant positioning, which can potentially confer improved outcomes. To date, only a few studies have evaluated the utilization of CT scan-based robotic-arm assisted THA in total hip arthroplasty, and those that do are not necessarily of the high-methodological quality. Therefore, the purpose of this review was to select the most recent and good- to high-quality studies focusing on robotic-assisted THA, to help provide a more comprehensive representation of postoperative outcomes. Specifically, we evaluated each study independently as well as performed a cumulative assessment of this most recent high-quality data. An extensive, cross-platform search of total hip arthroplasty on August 1, 2022 was performed. Studies were included only if they addressed robotic-assisted THA in comparison to manual techniques. Additional inclusion criteria consisted of studies scoring excellent (100 to 85 points) or good (84 to 70 points) based on their Coleman methodology score. Studies were evaluated as individual pieces of work, as well as a cumulative assessment. Specific outcomes evaluated were: component placement in safe zones, leg- length discrepancies, dislocation rates, clinical outcomes, patient clinical scores, patient-reported outcome measures (PROMS), lengths of stay, and costs. Overall, 24 studies were included for analyses. CT scan-based robotic-arm assisted THA had some potential key advantages as compared to manual techniques. Specifically, robotic-assisted THA was associated with more accurate component placement in safe zones, fewer chances of leg-length discrepancies, and lower risks of dislocation. Patient satisfaction and reported outcome measures were superior for CT scan-based robotic-arm assisted THA. Costs were also lower. Overall, 23 of 24 studies were positive for this technology, with one study of cases done between 2010 and 2014 more neutral. The robot led to positive findings for component placement in safe zones, leg-length discrepancies, dislocation rates, clinical outcomes, PROMS, lengths of stay, and costs. The current literature suggests potential advantages for CT scan-based robotic-arm assisted THA compared to manual THA. Surgeons should consider CT scan-based robotic-arm assisted THA for their patients given the multiple added benefits of improved clinical scores and PROMS, less dislocations (with a few exceptions reported), more component placements in safe zones, less leg-length discrepancies, decreased lengths of stay, and decreased episode-of-care costs.

Robotic-assisted versus manual total hip arthroplasty in obese patients: a retrospective case–control study

AimsThe objective of this study was to evaluate the accuracy of acetabular cup positioning in the obese patients when using robotic-assisted technology during total hip arthroplasty (THA).MethodsData were retrospectively collected from patients who underwent primary (THA) with a body mass index (BMI) ≥ 28 kg/m2 and ≥ 1 year of follow-up between January 2018 and December 2019. Their demographics, diagnosis, acetabular cup positioning, American Society of Anesthesiologists (ASA) score, Harris Hip Score (HHS), and Forgotten Joint Score (FJS) at the final follow-up were recorded for analysis.ResultsThere were no statistically significant differences between the two groups in height, weight, BMI, ASA score, or preoperative Harris Hip Score (HHS). Also, there was no difference in inclination angle between the two groups (R-THA: 41.29° ± 3.04°; manual THA (M-THA): 40.47° ± 5.46°; P = 0.312). However, the mean anteversion angle was greater in the R-THA group (20.71° ± 1.98° vs. 19.08° ± 4.04°; P < 0.001). Compared to M-THA, R-THA more frequently achieved an acetabular cup angle within 5° of the target (anteversion, 98.1% vs. 78.1% P = 0.001; inclination, 88.5% vs. 53.1%, P < 0.001). The R-THA group was more advantageous in restoring the hip center of rotation (COR) and leg length difference (LLD). There was no statistical difference in postoperative HHS (P = 0.404) or FJS (P = 0.497) between the two groups.ConclusionsCompared to manual technique, robotic-assisted technique provided more precise acetabular cup positioning and better leg length restoration for obese patients. The robotic-assisted technique was more advantageous in recovering the center of rotation position and achieved a higher proportion of the acetabular cup placed in the target safety zone. Further studies are needed to confirm the clinical outcomes of surgeries in obese patients using robotic-assisted technology.

Total Hip Arthroplasty with Robotic Arm Assistance for Precise Cup Positioning: A Case-Control Study.

ObjectiveTo determine whether more precise cup positioning can be achieved with robot‐assisted total hip arthroplasty (THA) as compared to conventional THA.MethodsIn this study, between July 2019 and May 2021, 93 patients aged 23–75 years with osteonecrosis of the femoral head (ONFH) and adult developmental dysplasia of hip who underwent first hip surgery were included in the study. They were randomly assigned to either the robotic‐assisted THA group (n = 45) or the conventional THA group (n = 48). After the operation, all patients were given routine rapid rehabilitation guidance. The duration of operation was recorded to estimate the learning curve through cumulative summation analysis. We compared the demographics, duration of operation, cup positioning, leg length discrepancy, hip offset, and Harris Hip Score between robot‐assisted THA and manual THA. Precision in the positioning of the acetabular prosthesis using the MAKO system was also compared between the two groups.ResultsThe mean duration of operation for the robot‐assisted THA group was 91.37 ± 17.34 min (range: 63 to 135 min), which was significantly higher than that for the conventional THA group. When the number of procedures was increased to 13, the duration of operation in the robot‐assisted group decreased significantly and gradually became stable. In terms of duration of operation, robot‐assisted THA was associated with a learning curve of 13 cases. The mean amount of bleeding in the robot‐assisted THA group was not significantly different from that in conventional THA group (328 ± 210 ml vs 315 ± 205 ml) (p = 0.741). There was no significant difference in the proportion of prostheses located within Lewinnek's safe zone between robot‐assisted THA group and conventional THA group (69.81% vs 64.41%). The leg length discrepancy (LLD) was significantly smaller in the robot‐assisted THA group than in the conventional THA group (p < 0.001), but both were within acceptable limits (10 mm). The inclination and anteversion angles of the acetabular prosthesis planned before operations were correlated with the actual measurement (r = 0.857 p < 0.001, r = 0.830, p < 0.001). After surgery, none of the patients experienced hip dislocation, aseptic loosening, or periprosthetic infection during the 3 months of follow‐up.ConclusionThe proportion of acetabular prostheses in the Lewinnek's safety zone was higher and the extent of LLD was significantly lower in the robot‐assisted THA group, as compared to the same metrics in the conventional THA group. The MAKO robot improved the accuracy of implant placement in THA.

Comparison of Surgical Time, Short-term Adverse Events, and Implant Placement Accuracy Between Manual, Robotic-assisted, and Computer-navigated Total Hip Arthroplasty: A Network Meta-analysis of Randomized Controlled Trials.

Recent years have observed the increasing utilization of robotic-assisted and computer navigation techniques in total hip arthroplasty (THA), given the proposed benefits of enhanced consistency and precision in implant placement. The purpose of this study was to conduct a systematic review of randomized controlled trials (RCTs) to determine whether differences in surgical times, adverse events, and implant positioning existed between manual, robotic-assisted, and computer navigation THA. PubMed, OVID/MEDLINE, and Cochrane databases were queried for RCTs comparing robotic-assisted versus manual THA and computer navigation versus manual THA at a minimum 1-year follow-up. Frequentist model network meta-analyses with P-scores were conducted to compare revisions, complications, and surgical times among the three treatment groups. A random-effects meta-analysis between computer navigation and manual THAs was conducted to analyze cup positioning because no robotic-assisted THA studies reported this outcome. Five RCTs compared robotic-assisted and manual THAs, while seven compared computer navigation and manual THAs. manual THA was associated with significantly reduced surgical time in comparison with computer navigation (mean difference: 23.3 minutes) and robotic-assisted THAs (mean difference: 8.6 minutes; P < 0.001). No difference was observed in the incidence of all-cause complications (computer navigation: 1.7%, manual: 6.6%, and robotic-assisted: 16.2%) or revisions (computer navigation: 1.0%, manual: 1.7%, and robotic-assisted 4.8%) among the three treatment groups based on the network meta-analysis. In three studies that reported acetabular implant positioning, computer navigation had a significantly higher percentage of acetabular cups placed in the Lewinnek "safe zone" compared with manual THA (79% versus 52%; P = 0.02). manual THA results in markedly shorter surgical times and a similar incidence of complications and revisions compared with robotic-assisted and computer navigation THAs, given the sample sizes available for study. However, computer navigation THA led to increased precision in the placement of acetabular implants.

A Cost-Utility Analysis of Robotic Arm-Assisted Total Hip Arthroplasty: Using Robotic Data from the Private Sector and Manual Data from the National Health Service.

Purpose The aim was to assess the cost-effectiveness of robotic arm-assisted total hip arthroplasty (rTHA) compared with manual total hip arthroplasty (mTHA) and to assess the influence of annual volume on the relative cost-effectiveness of rTHA. Methods A database of both rTHA (n = 48 performed in a private centre) and mTHA (n = 512 performed in the National Health Service) was used. Patient demographics, preoperative Oxford hip score, forgotten joint score, EuroQol 5-dimensional 3-level (EQ-5D), and postoperative EQ-5D were recorded. Two models for incremental cost-effectiveness ratios using cost per quality-adjusted life year (QALY) for rTHA were calculated based on a unit performing 100 rTHAs per year: 10-year follow-up and a lifetime time horizon (remaining life expectancy of a 69-year-old patient). Results When adjusting for confounding factors, rTHA was independently associated with a 0.091 (p=0.029) greater improvement in the EQ-5D compared to mTHA. This resulted in a 10-year time horizon cost per QALY for rTHA of £1,910 relative to mTHA, which increased to £2,349 per QALY when discounted (5%/year). When using the 10-year time horizon cost per QALY was approximately £3,000 for a centre undertaking 50 rTHAs per year and decreased to £1,000 for centre undertaking 200 rTHAs per year. Using a lifetime horizon, the incremental unadjusted cost per QALY gained was £980 and £1432 when discounted (5%/year) for rTHA compared with mTHA. Conclusions Despite the increased cost associated with rTHA, it was a cost-effective intervention relative to mTHA due to the associated greater health-related quality of health gain, according to the EQ-5D outcome measure.

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

BackgroundRobotic-assisted total hip arthroplasty (R-THA) affords precision yet uncertain clinical benefits. This study compares dislocation rates and related revisions between R-THA and manual total hip arthroplasty (M-THA). Secondarily we evaluated cup position, patient-reported outcome measures (PROMs), and postoperative complications. MethodsA three-surgeon cohort study was conducted on 2247 consecutive patients (1724 M-THA and 523 R-THA) who received a primary THA between January 2014 and June 2020 at a single hospital. Demographics, PROMs, emergency department visits, readmissions, and 90-day complications were collected via the Michigan Arthroplasty Registry Collaborative Quality Initiative. Chart review yielded instability occurrence with an average follow-up of 4 years. Multivariate regression analysis was performed, and a sample of 368 radiographs, including all dislocations, were assessed. ResultsThere were significantly lower rates of dislocation in R-THA (0.6%) vs M-THA (2.5%; Multivariate odds ratio 3.74, P < .046). All cases of unstable R-THA were successfully treated conservatively, whereas 46% of unstable M-THA were revised for recurrent instability. Cup anteversion (25.6° ± 5.4° R-THA vs 20.6° ± 7.6° M-THA) was greater, and cup inclination (42.5° ± 5.3° R-THA vs 47.0° ± 6.7° M-THA) was lower in the R-THA group (P < .05). No significant differences were noted for demographics, PROMs, or other complications (P > .05). ConclusionR-THA resulted in less than one-fourth the dislocation rate compared to M-THA and no revision for instability. It was associated with no difference in PROMs or other early complications. The influence of R-THA on stability goes beyond simply cup positioning and deserves further study.

Comparison of hip offset and rotation center reconstruction between robot-assisted and manual total hip arthroplasty

Objective: To compare the differences of hip offset and rotation center reconstruction between robot-assisted and manual total hip arthroplasty (THA). Methods: Patients underwent robot-assisted and manual THA from May to September of 2020 in the First Affiliated Hospital of Chongqing Medical University were enrolled in this study. The patients included 27 patients (28 hips) in robot-assisted THA (rTHA) group and 29 patients (31 hips) in manual THA (mTHA) group. In rTHA group, there were 16 males and 11 females, with a mean age of (59±13) years. In mTHA group, there were 18 males and 11 females, with a mean age of (63±14) years. Basic information, including gender, age, body mass index (BMI), diagnosis and functional scoring etc, were recorded. In rTHA group, Mako robot system was used for preoperative planning, intraoperative real-time location and navigation. In mTHA group, traditional preoperative template design and surgical procedure were carried out. Operation time and functional scoring were compared postoperatively. Femoral offset, acetabular offset, global offset, rotation center changes in vertical and horizontal directions were measured on pelvis X-ray and analyzed. The correlation between intraoperative feedback of global offset change in robot system and postoperative measured global offset were analyzed. Results: Operation time in rTHA group was (80±10) min, which was statistically longer than that in mTHA group ((58±18) min, P<0.001). With 6 months' follow-up, the Harris scoring in rTHA group was 94.9±2.8, which was statistically higher than that in mTHA group (93.1±2.8, P=0.017), however there was no statistic difference in WOMAC scoring between rTHA and mTHA group (7.0±3.8 vs 7.1±2.4, P=0.840). Absolute global offset change within 5 mm, 5-10 mm and lager than 10 mm were 71.4%(20/28), 28.6%(8/28) and 0 in rTHA group, which were 45.2%(14/31), 29.0%(9/31) and 25.8%(8/31) in mTHA group (all P<0.05). A positive relation was found between intraoperative feedback of global offset change in robot system and postoperative measured global offset in rTHA group (r=0.77, P<0.001). It was found that rotation center changes concentrated in outer upper quadrant in both groups, and rotation center change in rTHA group concentrated mainly in the area less than 10 mm, however, rotation center change in mTHA group was more dispersive compared with rTHA group. Conclusion: rTHA may accurately reconstruct hip offset and rotation center, intraoperation feedback of global offset change may be an effective reference.

Does robotic-assisted surgery improve outcomes of total hip arthroplasty compared to manual technique? A systematic review and meta-analysis.

Robot-assisted total hip arthroplasty (THA) is an emerging technology that claims to position implants with very high accuracy. However, there is currently limited data in literature on whether this improved accuracy leads to better long-term clinical outcomes. This systematic review compares the outcomes of THA done with the help of robotic assistance (RA) to those done with conventional manual techniques (MTs). Four electronic databases were searched for eligible articles that directly compared robot-assisted THA to manual THA and had data on the radiological or clinical outcomes of both. Data on various outcome parameters were collected. Meta-analysis was conducted using a random-effects model with 95% CIs. A total of 17 articles were found eligible for inclusion, and 3600 cases were analysed. Mean operating time in the RA group was significantly longer than in the MT group. RA resulted in significantly more acetabular cups being placed inside Lewinnek's and Callanan's safe zones (p<0.001) and had significantly reduced limb length discrepancy compared with MT. There were no statistically significant differences in the two groups in terms of incidence of perioperative complications, need for revision surgery and long-term functional outcome. RA leads to highly accurate implant placement and leads to significantly reduced limb length discrepancies. However, the authors do not recommend robot-assisted techniques for routine THAs due to lack of adequate long-term follow-up data, prolonged surgical times and no significant differences in the rate of complications and implant survivorship compared with conventional MTs.

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.

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 4,670mTHA caseswere included. 90-day EOC cost, index costs, length of stayand post-index rehabilitation utilization were assessed. Results: RATHA patients were significantly less likely to have post-index inpatient rehabilitation or skilled nursing facilityadmissions and used fewer home health agencyvisits, compared with mTHA patients. Total 90-day EOC costs for RATHA patients were found to be US$785 less than thoseof mTHA patients (p=0.0095). Conclusion: RATHA was associated with an overall lower 90-day EOC cost when compared with mTHA. The savings associated withRATHA were driven by reduced utilization and cost of post-index rehabilitation services.

Robotic-arm assisted versus manual total hip arthroplasty: Systematic review and meta-analysis of radiographic accuracy.

We systematically reviewed the radiological outcomes of studies comparing robotic-assisted (RA-THA) and manual total hip arthroplasty (mTHA). The PubMed, Embase, and Cochrane databases were queried from 1994-2021 for articles comparing radiographic outcomes between RA-THA and mTHA cohorts. A meta-analysis was conducted whenever sufficient data was present for common outcomes. Our analysis included 20 articles reporting on 4140 patients (RA-THA: n=1228; mTHA: n=2912). No differences were demonstrated for acetabular inclination or anteversion. However, RA-THA demonstrated higher rates of cup orientation within the Lewinnek and Callanan safe zones, improved femoral stem alignment, and lower global offset difference (GOD) and limb length discrepancy (all p-values <0.05). Superior femoral canal fill and combined offset were seen among RA-THA patients. Our review found that the use of RA-THA yields superior radiographic outcomes compared to mTHA counterparts. This information can inform healthcare systems considering investing in and implementing these technologies.

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.

Robotic-Assisted Total Hip Arthroplasty in Patients Who Have Developmental Hip Dysplasia

Introduction: Total hip arthroplasty (THA) in the setting of developmental dysplasia of the hip (DDH) presents more inherent complexities than routine primary THA for osteoarthritis. These include acetabular bone deficiency, limb length discrepancy (LLD), and abnormal femoral anteversion. Three-dimensional planning and robot-assisted (RA) bone preparation may simplify these complex procedures and make them more reproducible. The purpose of this study was to evaluate radiographic and clinical outcomes in a cohort of patients who had DDH and underwent an RA THA. Materials and Methods: We retrospectively analyzed 26 DDH patients who underwent RA THA by a single surgeon between 2013 and 2019. Their mean age was 54 years (range, 29 to 72 years) and mean follow up was approximately two years. Medical records were reviewed for demographics, clinical scores, Crowe classifications, and complications. There were thirteen Crowe I and seven Crowe II DDH hips, who were routinely managed with primary cementless implants. Two patients who had Crowe III and four patients who had Crowe IV DDH were also identified. All hips were reconstructed with cementless hemispherical acetabular components with or without the use of screws, but no acetabular augments or bulk allografts. Implants allowing control of femoral anteversion were selected in 23.1% of cases, including all six cases with Crowe III or IV dysplasia, and the need for these implants was uniformly identified using preoperative information about femoral version provided by the three-dimensional planning software. No patient was managed with a shortening femoral osteotomy. Postoperative radiographs were examined for LLD, center of rotation (COR), cup position (inclination and anteversion), and component osseous-integration. Results: Mean radiographic LLD was 1.7mm (range, -9 to +14) in patients who had Crowe I DDH, and there was no clinical LLDs greater than 5mm observed. Although patients who had Crowe II and greater DDH had a mean radiographic LLD of -11.6mm (range, -26 to +2.2), again no clinical LLD greater than 5mm was observed other than one patient who had bilateral Crowe II DDH in whom 10mm of clinical lengthening was accepted at the index arthroplasty with the plan to match lengths when her contralateral THA was performed. There were no cases of dislocation or acetabular fixation failure. One patient who had a femoral deformity and an intra-osseous blade plate from a prior femoral osteotomy suffered a failure of femoral osseous-integration, resulting in revision. A 32-point increase in mean modified Harris Hip Score (mHHS) was found (p=0.002), from 48 points preoperatively to 80 points postoperatively. Discussion: RA THA provides an excellent option for the arthroplasty surgeon to both preoperatively localize and characterize the acetabular deficiency, while providing a targeted, optimal, and secure placement of the components intraoperatively. Our results suggest favorable outcomes when compared to previous research on manual THA in DDH. Further studies, including comparative analyses, could discern possible advantages over traditional THA without robotic assistance in DDH. Conclusion: Total hip arthroplasty (THA) in the setting of developmental dysplasia presents more inherent complexities than routine primary THA. Robotic-assisted THA may simplify these complex procedures.

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

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). 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. 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. 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 J2021;103-B(6):1009-1020.

Comparison of Outcomes After Robotic-Assisted or Conventional Total Hip Arthroplasty at a Minimum 2-Year Follow-up: A Systematic Review.

This systematic review aimed to present an updated analysis of the evidence comparing outcomes between robotic-assisted total hip arthroplasty (robotic THA) and conventional manual total hip arthroplasty (manual THA). A PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) systematic review was performed using the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, MEDLINE, and Embase. Controlled studies comparing primary robotic THA and manual THA utilizing patient-reported outcome measures (PROMs) at a minimum follow-up of 2 years were included. We also compared radiographic outcomes, dislocation rates, and revision surgical procedures between groups. The ROBINS-I (Risk of Bias in Non-Randomized Studies - of Interventions) and Cochrane Risk of Bias 2.0 tools were used to assess study quality and risk of bias. Of 765 studies identified, 7 articles comparing robotic THA with manual THA met inclusion criteria. A total of 658 patients were assessed, 335 of whom underwent robotic THA. The majority of studies found no significant differences (p > 0.05) in PROMs between the 2 techniques. Two low-quality studies (Level III) found significantly better postoperative PROMs favoring robotic THA at 2 years. When assessing radiographic outcomes, 6 studies showed that robotic THA resulted in more consistent and accurate component placement. No differences in postoperative dislocations, complications, or revision rates were found between groups except in 1 study, which found significantly more dislocations and revisions in the robotic THA cohort. Reported operative times were a mean of 12 to 25 minutes longer when using robotic THA. The existing literature comparing robotic THA and manual THA is scarce and low-quality, with findings limited by methodological flaws in study design. Although evidence exists to support increased accuracy and reproducibility of THA component placement with robotic THA, this has not been shown to reduce postoperative dislocation and revision rates. Based on the available evidence, functional outcomes are comparable between techniques, and robotic THA appears to be associated with longer operative times. To fully evaluate the utility of robotic THA, additional well-designed, prospective controlled studies with continuous long-term monitoring are required. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Robotic arm-assisted versus manual total hip arthroplasty.

AimsThe 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.MethodsA 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.ResultsThere 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).ConclusionPatients 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.

Robotic-Arm Assisted Direct Anterior Total Hip Arthroplasty; Improving Implant Accuracy

Introduction: The aim of this study was to investigate the accuracy of implant position of robotic-arm assisted total hip arthroplasty (THA) via the direct anterior approach (DAA). Materials and Methods: All patients who underwent robotic-arm assisted DAA THA (MAKO Surgical Corp., Ft. Lauderdale, Florida) from November 2018 to January 2020 were prospectively followed up. Pelvis indices (limb length discrepancy, femoral and hip offset, implant inclination, and anteversion), surgical duration, length of stay, and complications were recorded. To further evaluate the accuracy of robotic-arm assisted THA, patients who underwent manual DAA THA by the same surgeon were match-paired with the study group. Results: Twenty-five patients underwent robotic-arm assisted DAA THR. Limb length discrepancy was restored to 0.1mm (±3.4mm) from 10.0mm (±6.4mm) postoperatively. Preoperatively, the difference in femoral offset was 5.1mm (±5.1mm), and this was corrected to 1.9mm (±6.5mm) postoperatively. Nine cases had target inclination of 40° and mean inclination achieved was 40.7° (±0.9°). Sixteen cases had target inclination of 45° and mean inclination achieved was 45.3° (±1.0°). Mean anteversion was 19.5° (±2.4°). Propensity matched analysis showed that the root mean square errors for manual cup implantation compared to the robotic-arm assisted group was 2.3 times higher for anteversion and 6.3 times higher for inclination. Fourteen (56%) of the cups were within Callanan safe-zone and 18 (72%) within Lewinnek safe-zone in the manual group compared to 18 (72%) and 25 (100%), respectively, in the robotic-arm assisted group. Conclusion: Combining the muscle-sparing technique of DAA with the improved implant placement with the robotic-arm assisted platform is a promising solution to improving THA outcomes.

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.].

Computerised tomography-based planning with conventional total hip arthroplasty versus robotic-arm assisted total hip arthroplasty: study protocol for a prospective randomised controlled trial

BackgroundRobotic-arm assisted surgery aims to reduce manual errors and improve the accuracy of implant positioning during total hip arthroplasty. The objective of this study is to compare the accuracy of implant positioning, restoration of hip biomechanics, patient satisfaction, functional outcomes, implant survivorship, cost-effectiveness, and complications in conventional manual total hip arthroplasty (CO THA) versus robotic-arm assisted total hip arthroplasty (RO THA). Preoperative pelvic computerised tomography (CT) scans will be used to create patient-specific, virtual, three-dimensional reconstructions for surgical planning in both treatment groups.Methods and analysisThis prospective randomised controlled trial will include 60 patients with symptomatic hip osteoarthritis undergoing primary THA. Following informed consent, patients will be randomised to CO THA (control group) or RO THA (investigation group) at a ratio of 1:1 using an online random number generator. Observers will review patients at regular intervals for 2 years after surgery to record predefined study outcomes relating to the accuracy of implant positioning, hip biomechanics, postoperative rehabilitation, clinical progress, functional outcomes, cost-effectiveness, and complications. Primary and secondary objectives will be used to quantify and draw inferences on differences in the efficacy of treatment between the two groups. Intention-to-treat and per-protocol population analysis will be undertaken. Intention to treat relates to the allocated treatment (CO THA or RO THA), and per-protocol refers to the actual treatment received by the patient. The following statistical methods will be employed to analyse the data: descriptive statistics, independent t test, paired t test, analysis of variance, Fisher exact test, chi-square test, and graphical displays. Ethical approval was obtained from the London-Bromley Research Ethics Committee, UK. The study is sponsored by University College London, UK.DiscussionThis study compares a comprehensive and robust range of clinical, functional, and radiological outcomes in CT-planned CO THA versus CT-planned RO THA. The findings of this study will enable an improved understanding of the differences in CO THA versus RO THA with respect to patient satisfaction, functional outcomes, implant survivorship, cost-effectiveness, and complications.Trial registrationClinicalTrials.gov NCT04095845. Registered on 19 September 2019

Robotic Arm-assisted Total Hip Arthroplasty is More Cost-Effective Than Manual Total Hip Arthroplasty: A Markov Model Analysis.

Total hip arthroplasty (THA) is the benchmark surgical treatment of advanced and symptomatic hip osteoarthritis. Preliminary evidence suggests that the robotic arm-assisted (RAA) technology yields more accurate and reproducible acetabular cup placement, which may improve survival rate and clinical results, but economic considerations are less well-defined. The purpose of this study was to compare the cost effectiveness of the RAA THA with manual THA (mTHA) modalities, considering direct medical costs and utilities from a payer's perspective. A Markov model was constructed to analyze two potential interventions for hip osteoarthritis and degenerative joint disorder: RAA THA and mTHA. Potential outcomes of THA were categorized into the transition states: infection, dislocation, no major complications, or revision. Cumulative costs and utilities were assessed using a cycle length of 1 year over a time horizon of 5 years. RAA THA cohort was cost effective relative to mTHA cohort for cumulative Medicare and cumulative private payer insurance costs over the 5-year period. RAA THA cost saving had an average differential of $945 for Medicare and $1,810 for private insurance relative to mTHA while generating slightly more utility (0.04 quality-adjusted life year). The preferred treatment was sensitive to the utilities generated by successful RAA THA and mTHA. Microsimulations indicated that RAA THA was cost effective in 99.4% of cases. In the Medicare and private payer scenarios, RAA THA is more cost effective than conventional mTHA when considering direct medical costs from a payer's perspective. Economic Level III. Computer simulation model (Markov model).