Abstract
Robot-assisted total hip arthroplasty (THA), in comparison to conventional THA, improves radiographic outcomes, but it remains unclear whether it alters complication rates, clinical and functional outcomes, and implant survival.
The purpose of this systematic overview was to summarize the findings of the most recent meta-analyses that compare clinical and surgical outcomes of robot-assisted versus conventional THA.
Two readers independently conducted an electronic literature search, screening and data extraction from five electronic databases. Inclusion criteria were: meta-analyses evaluating robot-assisted versus conventional THA in terms of radiographic outcomes, clinical and functional scores, and complications and revision rates. The literature search returned 67 records, of which 14 were duplicates and 49 were excluded, leaving three meta-analyses published within the past two years for data extraction and analysis.
The present overview of meta-analyses suggests that, compared to conventional THA (n = 3011), robot-assisted THA (n = 1813) improves component placement and reduces intraoperative complications. The overview also affirms that robot-assisted THA could extend surgery by 20 minutes, and increases risks of postoperative heterotopic ossification, dislocation, and revision. None of the meta-analyses found significant differences in clinical or functional scores between robot-assisted and conventional THA.
Future studies and reviews should make a clear distinction between active and semi-active robotic assistance, address technology matureness, and describe the experience of surgeons with robotic assistance.
Cite this article: EFORT Open Rev 2021;6:1157-1165. DOI: 10.1302/2058-5241.6.200121
Introduction
In an attempt to improve accuracy and consistency of implant placement during total hip arthroplasty (THA), multiple navigation technologies have been introduced over the past three decades,1 which can be broadly characterized as computer-assisted navigation systems, or robot-assisted systems.2 Robotic systems, which are utilized across many surgical subspecialties,3 can be classified as either active systems, which work autonomously to perform the planned bone resections, or semi-active systems, which provide full control to the surgeon with live intraoperative feedback to limit deviation from the preoperative surgical plan.4 Although robotic assistance in THA improves precision and accuracy,5 it remains unclear whether it alters complication rates, clinical and functional outcomes, and implant survival.6
Over the last three years, numerous meta-analyses pooled data from published studies that compared outcomes of robot-assisted versus conventional THA. To the authors’ knowledge, there is no published overview of these meta-analyses to summarize the latest evidence in terms of the effect of robot-assisted THA on rates of complications, clinical and functional outcomes, or implant survival. The purpose of this overview was therefore to summarize the findings of the most recent meta-analyses on the efficacy of robot-assisted versus conventional THA, and highlight any differences in surgical and clinical outcomes. This overview is expected to highlight gaps in the literature and help decision-makers justify clinical and economic benefits of robotic assistance.7
Material and methods
The protocol for this overview of systematic reviews and meta-analyses, including the search strategy and proposed methodology, was registered with PROSPERO (CRD42020181669).
Search strategy
The authors conducted an electronic literature search using Allied & Complementary Medicine™, Embase®, MEDLINE®, Web of Science, Cochrane Database of Systematic Reviews on 11 February 2020. Key words used to develop search strategy were (“hip” OR “knee”) AND (“arthroplasty” OR “replacement”) AND (“robot” OR “robot*”) AND “meta-analysis” (see full search strategy in PROSPERO registration). While the original search strategy included both hip and knee arthroplasty, it was subsequently resolved that only results regarding primary THA would be included.
Two reviewers (JHM and KJC) independently performed the literature search described. Grey literature regarding robot-assisted THA was searched and an expert in the field (NK) consulted for other relevant publications not identified in the electronic search. Review registries were checked for ongoing reviews on the subject. Disagreements between reviewers were discussed and resolved by consensus.
Study selection and data extraction
Titles and abstracts of the studies were screened independently by two reviewers (JHM and KJC) to determine relevance according to the inclusion and exclusion criteria presented below.
Inclusion criteria
Original meta-analyses that:
- reported on studies evaluating robot-assisted, both active or semi-active, compared to conventional primary THA for any indication.
- presented results in terms of:
- radiographic outcomes (such as limb and joint alignment, component placement).
- clinical scores (such as Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)).
- complication rates (intra- and postoperative complications).
- implant survival or revision rates (such as Kaplan-Meier, Cumulative Incidence Function).
Exclusion criteria
Meta-analyses that:
- reported outcomes for robot-assisted surgery for other joints without separating data regarding THA.
- were written in languages other than English, to avoid translation errors.
Full-text articles were retrieved if the article passed the first eligibility screening or if the title or abstract provided insufficient information to establish eligibility. Disagreements in screening decisions between the reviewers were discussed and resolved by review and consensus. The reference lists of all selected publications were checked for relevant studies that may have been missed in the electronic search.
Data extraction and quality assessment
Two reviewers (JHM and KJC) extracted characteristics of meta-analyses independently including: year of publication, journal, number and type of studies included, countries in which included studies were performed, intervention and comparator details, number of patients included per intervention and comparator, follow-up period, type of robot used, pooled outcomes recorded by at least three studies. Pooled outcome data reported by the meta-analyses included reported effect size and statistical significance. Results of data extraction were compared and where discrepancies were found, consensus was reached through review and discussion between the reviewers.
The same two reviewers (JHM and KJC) assessed the methodological quality of eligible studies according to the 16 domains outlined by A MeaSurement Tool to Assess systematic Reviews (AMSTAR-2).8 Where there was disagreement between reviewers in their appraisal of study quality, consensus was achieved through review and discussion.
Interpretation of results
Methodological differences across meta-analyses made pooling or direct statistical comparison of results impossible. As a result, findings extracted from each meta-analysis were presented as reported and synthesized narratively, rather than normalized to a single comparable metric. Differences in outcomes were reported as weighted mean difference (WMD) or weighted odds ratio (WOR) and considered statistically significant if p < 0.05.
Results
Literature search
The electronic literature search returned 67 records, of which 14 were duplicates. A further 49 articles were excluded after reading their titles or abstracts (46 did not include THA; two did not include robotic assistance, and one was not written in English), and an additional article9 was excluded after reading its full text, as it included < 3 studies per outcome of interest, leaving a total of three meta-analyses eligible for quality assessment and data extraction (Fig. 1).2,10,11
Flowchart of the study selection procedure.
Note. THA, total hip arthroplasty; RA, robotic-assisted.
Citation: EFORT Open Reviews 6, 12; 10.1302/2058-5241.6.200121
Characteristics of included studies
The three meta-analyses, all published within the past two years, assessed a total of 15 comparative studies reporting outcomes of 1813 hips that received robot-assisted THA and 3011 hips that received conventional THA. The majority of studies originated from the USA (n = 7),5,12–17 and the most frequently used system was the ROBODOC which provides active assistance (THINK Surgical, Inc., Fremont, CA, n = 8 studies).12,18–24 Of the 15 studies, five,19,21,23–25 were included by all three meta-analyses, two12,20 were included by both Han et al2 and Karunaratne et al,10 two16,17 were included by both Han et al2 and Chen et al,11 five5,14,15,18,22 were included only by Han et al,2 and one13 was included only by Karunaratne et al10 (Table 1). It is worth noting that all three meta-analyses pooled results of older and possibly obsolete robotic systems with results of newer generations and enhanced robotic systems, which may be a methodological flaw. While the meta-analyses did not distinguish between outcomes of old (such as ROBODOC (ORTHODOC) and Caspar) and new (such as Mako) systems, which makes it impossible to present their results separately, inspection of forest plots revealed no consistent differences in outcomes of old versus new systems.
Characteristics of included studies
| Han et al, 20192 | Karunaratne et al, 201910 | Chen et al, 201811 | |
|---|---|---|---|
| Journal | Int J Med Robot Comp | Int Orthop | Postgrad Med J |
| Population | THA | THA | THA |
| Intervention (robotic-assisted, hips) | 817 | 474 | 522 |
| Comparator (conventional, hips) | 1536 | 481 | 994 |
| Outcomes reported by ≥ 3 studies | |||
| Radiographic outcomes | yes | yes | |
| Clinical scores | yes | yes | yes |
| Complication and revision rates | yes | yes | |
| Operation time | yes | yes | |
| Follow-up (months, range) | (0–168) | (18–60) | (0–60) |
| Studies assessed | |||
| Total (unique inclusions) | 14 (5) | 8 (1) | 7 (0) |
| RCT | 5 | 4 | 2 |
| Cohort | 1 | 1 | 1 |
| Case-control | 8 | 3 | 4 |
| Robots | |||
| ROBODOC | 8 | 6 | 4 |
| CASPAR | 1 | 1 | 1 |
| MAKO | 5 | 1 | 2 |
| Countries | |||
| USA | 6 | 2 | 2 |
| Japan | 4 | 3 | 3 |
| Germany | 3 | 2 | 1 |
| Korea | 1 | 1 | 1 |
Note. THA, total hip arthroplasty; RCT, randomized controlled trial.
Quality assessment of included meta-analyses
According to AMSTAR-2, methodological quality was ‘low’ for Karunaratne et al10 due to weakness in a critical domain, and ‘critically low’ for the remaining two studies2,11 due to weaknesses in two or more critical domains (Table 2, Fig. 2). All three meta-analyses failed to apply appropriate methods for data synthesis; neither Han et al2 nor Chen et al11 prospectively published their review protocols in advance, listed or justified excluded studies, or considered risk of bias when interpreting their results.
Evaluation of the quality of meta-analyses on RA THA using AMSTAR-2
| First author, year | Han et al, 20192 | Karunarante et al, 201910 | Chen et al, 201811 |
|---|---|---|---|
| Intervention | THA | THA & TKA | THA |
| 1. Research questions and criteria included PICO | N | Y | Y |
| 2. Published review protocol prior (c) | N | Y | N |
| 3. Explained study design inclusion criteria | N | N | Y |
| 4. Comprehensive literature search strategy (c) | P | Y | P |
| 5. Performed study selection in duplicate | Y | Y | Y |
| 6. Performed data extraction in duplicate | Y | Y | Y |
| 7. Excluded studies listed and justified (c) | N | Y | N |
| 8. Included studies described in adequate detail | P | P | P |
| 9. Included studies assessed for RoB (c) | Y | Y | P |
| 10. Reported sources of funding for studies | N | N | N |
| 11. Appropriate methods for data synthesis (c) | N | N | N |
| 12. Assessed impact of RoB in each study | Y | Y | N |
| 13. Considered RoB when interpreting results (c) | N | Y | N |
| 14. Observed heterogeneity & impact explained | N | Y | N |
| 15. Investigated publication bias (c) | Y | Y | N |
| 16. Reported own conflict of interests & funding | Y | Y | Y |
| Number of critical weaknesses | 4 | 1 | 5 |
| Result (AMSTAR-2) | Critically low | Low | Critically low |
Note. THA, total hip arthroplasty; TKA, total knee arthroplasty; RA, robotic-assisted; AMSTAR-2, A MeaSurement Tool to Assess systematic Reviews; PICO, Population Intervention Comparator Outcome; RoB, risk of bias; c, critical.
Critical AMSTAR-2 domains for the assessment of the meta-analyses.
Note. AMSTAR-2, A MeaSurement Tool to Assess systematic Reviews; PICO, Population Intervention Comparator Outcome; RoB, risk of bias; c, critical.
Citation: EFORT Open Reviews 6, 12; 10.1302/2058-5241.6.200121
Radiographic outcomes
Chen et al11 reported on radiographic outcomes, which could not be considered because they had fewer than three clinical studies on each outcome. Han et al2 reported on radiographic outcomes, including acetabular cup inclination, cup anteversion, stem alignment, cup safe zones (Lewinnek and Callanan) and leg length discrepancy (> 3 or > 10 mm). They found that robot-assisted THA improved both cup inclination (WMD, 2.47°; p = 0.03) and stem alignment (WMD, 0.4°; p = 0.02), as well as positioning within the Lewinnek safe zone (WOR, 11.05; p < 0.001) and the Callanan safe zone (WOR, 7.63; p < 0.001) (Table 3).
All reported outcomes of THA using robotic assistance and conventional instrumentation
| Han et al, 20192 | Karunaratne et al, 201910 | Chen et al, 201811 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Unit | n* | Effect size | p-value | Favours | n* | Effect size | p-value | Favours | n* | Effect size | p-value | Favours | |
| Radiographic outcomes | |||||||||||||
| Cup inclination (degrees) | WMD | 4 | –2.47 | 0.003 | RA | ||||||||
| Cup anteversion (degrees) | WMD | 4 | –1.63 | 0.600 | |||||||||
| Stem alignment (degrees) | WMD | 6 | –0.40 | 0.020 | RA | ||||||||
| Cup safe zone Lewinnek | WOR | 4 | 11.05 | < 0.001 | CI | ||||||||
| Cup safe zone Callanan | WOR | 4 | 7.63 | < 0.001 | CI | ||||||||
| LLD (> 3 or > 10 mm) | WOR | 4 | 0.74 | 0.280 | |||||||||
| Clinical scores | |||||||||||||
| Pooled HHS, PMA & JOA score | WMD | 10 | 0.01 | 0.970 | 3 | 0.09 | 0.380 | ||||||
| Pooled mHHS and HHS | WMD | 4 | –2.90 | n.r. | |||||||||
| PMA score | WMD | 4 | 0.06 | 0.860 | 4 | –1.25 | n.r. | ||||||
| HHS | WMD | 4 | 0.04 | 0.980 | |||||||||
| Complications and revision | |||||||||||||
| Intraoperative complication | WOR | 9 | 0.32 | 0.006 | RA | 5 | 0.12 | < 0.0001 | RA | ||||
| Nerve palsy | WOR | 3 | 4.47 | 0.110 | |||||||||
| Thigh pain | WOR | 3 | 0.32 | 0.030 | RA | ||||||||
| Heterotopic ossification | WOR | 4 | 1.44 | 0.290 | 3 | 1.94 | 0.040 | CI | |||||
| Dislocation | WOR | 6 | 2.28 | 0.020 | CI | ||||||||
| Total complications | WOR | 7 | 0.83 | 0.480 | 5 | 0.43 | 0.030 | RA | |||||
| Revision rate | WOR | 3 | 2.88 | 0.030 | CI | ||||||||
| Operation time (minutes) | WMD | 8 | 20.72 | 0.002 | CI | 3 | 23.21 | 0.090 | |||||
Number of studies assessing an outcome.
Note. THA, total hip arthroplasty; RA, robotic-assisted; CI, conventional instrumentation; WMD, weighted mean difference; WOR, weighted odds ratio; HHS, Harris Hip Score; PMA, Postel-Merle d'Aubigné; JOA, Japanese Orthopaedic Association; mHHA, modified Harrris Hip Score; LLD, leg length discrepancy; n.r., not reported.
Functional outcomes
Han et al2 reported weighted HSS, Postel-Merle d’Aubigné (PMA) and pooled different scores (HSS, PMA and Japanese Orthopedic Association (JOA)). Karunaratne et al10 reported weighted PMA and pooled HHS and modified HHS together. Chen et al11 did not report any weighted scores, but pooled different scores (HSS, PMA and JOA). None of the meta-analyses found statistically significant differences in clinical scores between robot-assisted and conventional THA (Table 3).
Complications and survival
Both Han et al2 and Chen et al11 found that robot-assisted THA decreased intraoperative complications (respectively: WOR, 0.32; p = 0.006 and WOR, 0.12; p < 0.001). Chen et al11 found that robot-assisted THA decreased overall complications (WOR, 0.42; p = 0.03), whereas Han et al2 found no significant difference. Han et al2 reported that robot-assisted THA increased dislocation (WOR, 2.28; p = 0.02) and revisions (WOR, 2.88; p = 0.03), and Chen et al11 likewise reported that robot-assisted THA increased heterotopic ossification (WOR, 1.94; p = 0.04) (Table 3).
Operation time
Both Han et al2 and Chen et al11 found that robot-assisted THA extends operation time by about 20 minutes. Han et al2 found a statistically significant difference (WMD, 20.72 minutes; p = 0.002), while Chen et al11 did not (WMD, 23.21 minutes) (Table 3).
Conclusions of meta-analyses
All three meta-analyses concluded that postoperative clinical results were equivalent, with both Chen et al11 and Karunaratne et al10 calling for further studies to ascertain long-term outcomes. Both Chen et al11 and Han et al2 further concluded that while robot-assisted THA requires longer operation times, it incurs fewer intraoperative complications and better radiographic outcomes. Chen et al11 also concluded that robot-assisted THA increases likelihood of heterotopic ossification, while Han et al2 concluded that it is associated with a higher incidence of dislocations and revisions.
Discussion
The present overview of meta-analyses suggests that, compared to conventional THA, robot-assisted THA grants more accurate cup inclination and stem alignment, higher likelihood of component placement within safe zones, and fewer intraoperative complications. The overview also affirms that robot-assisted THA extends operation times by about 20 minutes, and increases risks of postoperative heterotopic ossification, dislocation, and revision. None of the meta-analyses found significant differences in clinical or functional scores between robot-assisted and conventional THA.
The two meta-analyses2,11 that reported on radiographic outcomes found that, compared to conventional THA, robot-assisted THA enabled more accurate and reproducible acetabular cup placement within the Lewinnek safe zone26 and the Callanan safe zone.27 The validity of both safe zones has been challenged,28–30 because subluxations and dislocations have also been observed for cups that were placed within the safe zones. As a result, several additional safe zones have been proposed that show an improved accuracy of component positioning,29–31 but these were not used in the studies assessed by the meta-analyses. Moreover, a recent systematic review on acetabular cup positioning and risk of dislocation suggested that it is difficult to draw any conclusions regarding definitive target zones for cup positioning due to high heterogeneity among studies with inconsistent measurement techniques and different surgical approaches.32 The authors therefore believe that ideal cup placement should be determined considering spino-pelvic parameters, such as pelvic tilt and functional anteversion, which could be facilitated by a robotic system.33–35
The meta-analyses revealed more accurate stem placement with robot-assisted THA, but there remains inconsistency in standards for classification of stem alignment.11 Leg length discrepancy (LLD) remains one of the most common causes of patient dissatisfaction after THA, though there is no consensus as to whether the cut-off should be 3 mm, 5 mm or 10 mm.2,11 The three meta-analyses found no statistically significant differences in LLD between robot-assisted and conventional THA, either in terms of absolute difference or proportion of outliers.2,11 Robotic systems provide an accurate way to assess LLD that may help surgeons make intraoperative adjustments and/or improve their preoperative planning or component positioning.
Based on the findings of the current overview, robotic assistance has no added benefit in terms of clinical and functional scores at 5 to 14 years.2,10,11 It should be noted, however, that the use of different scoring systems across studies complicates evaluation of any pooled results. Han et al2 noted that in a study by Bargar et al,18 robotic assistance yielded significantly better pain scores (Health Status Questionnaire and Harris Pain Scores) as well as WOMAC scores at a mean follow-up of 14 years (robot-assisted THA, 13.9±2.7 years; conventional THA, 14.2±4.7 years).
In the meta-analysis by Chen et al11 the rates of infection, nerve palsy and deep vein thrombosis were comparable between robot-assisted and conventional THA. Han et al2 revealed significantly higher dislocation and revision rates with robotic assistance. It is worth noting, however, that studies published after 2003 observed lower dislocation rates following robot-assisted THA.20 This decrease might be attributable to the inclusion of five studies19,21,23–25 that followed a posterolateral approach, which provides better retraction of the gluteus medius and minimus muscles, thereby granting improved access for robotic milling and avoiding injury to the abductor tendon and greater trochanter.23 It is noteworthy that studies evaluating active robot-assisted THA reported outcomes at 1.5 to 14 years,12,18–25 whereas studies evaluating semi-active robot-assisted THA reported outcomes at only 0 to 2 years.5,13–17 The long-term outcomes of semi-active robot-assisted THA are therefore yet to be determined.
Both of the meta-analyses that assessed operation time indicated that robot-assisted THA took longer than conventional THA, possibly because robotic systems require registration or placement of positioning pins, as well as the learning curve for new users. The latter has not been addressed in the meta-analyses which did not consider the level of experience of the surgeons. There are few reports on the learning curve of robot-assisted THA.2 One study observed a significant learning curve, with operation time decreasing from 79.8 minutes (1st to 35th case) to 69.4 minutes (71st to 105th cases),36 whereas another study found surgeons were able to grasp the technology after only 10 procedures.5 A third study compared one surgeon’s experience switching from conventional to robot-assisted THA, and found that over the course of 100 surgeries, it took 14 surgeries to become ‘proficient’, beyond which there were no significant differences in operation time or HHS.37
The findings of this overview of meta-analyses should be interpreted with the following considerations and limitations in mind. First, only three meta-analyses fulfilled the inclusion criteria, and their quality was either ‘low’ or ‘critically low’. Moreover, all three meta-analyses included nine case-control studies and one cohort study in addition to five randomized controlled trials. Second, only one meta-analysis10 differentiated between active and semi-active assistance, whereas results from both systems were pooled in the other two meta-analyses.2,11 Moreover, all three meta-analyses pooled results of older and possibly obsolete robotic systems with results of newer generations and enhanced robotic systems. This may be problematic as blending results across different robotic assistance techniques and generations may invalidate the data syntheses performed. Third, there was heterogeneity in terms of surgical approaches, and it is impossible to differentiate the effect of surgical approach from that of robotic assistance. Fourth, it is impossible to account for the effect of learning curves and experience in the included meta-analyses. Fifth, only the Lewinnek et al26 and Callanan et al27 safe zones for acetabular component positioning were assessed, while newer safe zones were not accounted for. Safe zones enable quantitative assessments of how well surgeons followed their preoperative plans, and hence how to improve their techniques and targets for future operations. Sixth, ‘human error’ remains a major weakness in THA,6 since it is impossible to implant perfectly positioned components in every patient with their varying biological environments, diverse anatomy, and pathology. It is unknown whether and in how many cases surgeons might have diverted from the preoperative plan, and how this affected the reported outcomes. Seventh, technology has evolved greatly over the last two decades and is still evolving very fast.7 Therefore the question arises whether data can be pooled for technologies of different generations and working methods.
Conclusion
The present overview of meta-analyses suggests that robot-assisted THA could improve the accuracy of component positioning and reduce intraoperative complications. The overview also affirms that robot-assisted THA extends surgery by 20 minutes, and increases risks of postoperative heterotopic ossification, dislocation, and revision. None of the meta-analyses found significant differences in clinical or functional scores between robot-assisted and conventional THA. Future studies and reviews should make a clear distinction between active and semi-active robotic assistance, address technology matureness, and consider surgeon experience.
Open access
This article is distributed under the terms of the Creative Commons Attribution-Non Commercial 4.0 International (CC BY-NC 4.0) licence (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed.
The authors are grateful for the contributions of Kyung-Jin Cho who assisted with the electronic literature collection and screening process. The authors are grateful to Mo Saffarini for his assistance with manuscript preparation.
NK reports being a consultant for BodyCad, Stryker, Zimmer-Biomet, Bioventus, outside the submitted work. PS reports no conflicts of interest. PP reports former employment at Zimmer Biomet. JHM reports no conflicts of interest.
The review and manuscript preparation were funded by Stichting IMA.
The author or one or more of the authors have received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this article.
This article is distributed under the terms of the Creative Commons Attribution-Non Commercial 4.0 International (CC BY-NC 4.0) licence (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed.
References
- 1.↑
Renner L Janz V Perka C Wassilew GI . What do we get from navigation in primary THA? EFORT Open Rev 2017;1:205–210.
- 2.↑
Han PF Chen CL Zhang ZL, et al. Robotics-assisted versus conventional manual approaches for total hip arthroplasty: a systematic review and meta-analysis of comparative studies. Int J Med Robot 2019;15:e1990.
- 3.↑
D’Souza M Gendreau J Feng A Kim LH Ho AL Veeravagu A . Robotic-assisted spine surgery: history, efficacy, cost, and future trends. Robot Surg 2019;6:9–23.
- 4.↑
Kayani B Konan S Ayuob A Onochie E Al-Jabri T Haddad FS . Robotic technology in total knee arthroplasty: a systematic review. EFORT Open Rev 2019;4:611–617.
- 5.↑
Kamara E Robinson J Bas MA Rodriguez JA Hepinstall MS . Adoption of robotic vs fluoroscopic guidance in total hip arthroplasty: is acetabular positioning improved in the learning curve? J Arthroplasty 2017;32:125–130.
- 6.↑
Subramanian P Wainwright TW Bahadori S Middleton RG . A review of the evolution of robotic-assisted total hip arthroplasty. Hip Int 2019;29:232–238.
- 7.↑
Zagra L . Advances in hip arthroplasty surgery: what is justified? EFORT Open Rev 2017;2:171–178.
- 8.↑
Shea BJ Reeves BC Wells G, et al. AMSTAR 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both. BMJ 2017;358:j4008.
- 9.↑
Tan A Ashrafian H Scott AJ, et al. Robotic surgery: disruptive innovation or unfulfilled promise? A systematic review and meta-analysis of the first 30 years. Surg Endosc 2016;30:4330–4352.
- 10.↑
Karunaratne S Duan M Pappas E, et al. The effectiveness of robotic hip and knee arthroplasty on patient-reported outcomes: a systematic review and meta-analysis. Int Orthop 2019;43:1283–1295.
- 11.↑
Chen X Xiong J Wang P, et al. Robotic-assisted compared with conventional total hip arthroplasty: systematic review and meta-analysis. Postgrad Med J 2018;94:335–341.
- 12.↑
Bargar WL Bauer A Börner M . Primary and revision total hip replacement using the Robodoc system. Clin Orthop Relat Res 1998;354:82–91.
- 13.↑
Bukowski BR Anderson P Khlopas A Chughtai M Mont MA Illgen RL II . Improved functional outcomes with robotic compared with manual total hip arthroplasty. Surg Technol Int 2016;29:303–308.
- 14.↑
Tsai TY Dimitriou D Li JS Kwon YM . Does haptic robot-assisted total hip arthroplasty better restore native acetabular and femoral anatomy? Int J Med Robot 2016;12:288–295.
- 15.↑
El Bitar YF Stone JC Jackson TJ Lindner D Stake CE Domb BG . Leg-length discrepancy after total hip arthroplasty: comparison of robot-assisted posterior, fluoroscopy-guided anterior, and conventional posterior approaches. Am J Orthop 2015;44:265–269.
- 16.↑
Domb BG El Bitar YF Sadik AY Stake CE Botser IB . Comparison of robotic-assisted and conventional acetabular cup placement in THA: a matched-pair controlled study. Clin Orthop Relat Res 2014;472:329–336.
- 17.↑
Domb BG Redmond JM Louis SS, et al. Accuracy of component positioning in 1980 total hip arthroplasties: a comparative analysis by surgical technique and mode of guidance. J Arthroplasty 2015;30:2208–2218.
- 18.↑
Bargar WL Parise CA Hankins A Marlen NA Campanelli V Netravali NA . Fourteen year follow-up of randomized clinical trials of active robotic-assisted total hip arthroplasty. J Arthroplasty 2018;33:810–814.
- 19.↑
Hananouchi T Sugano N Nishii T, et al. Effect of robotic milling on periprosthetic bone remodeling. J Orthop Res 2007;25:1062–1069.
- 20.↑
Honl M Dierk O Gauck C, et al. Comparison of robotic-assisted and manual implantation of a primary total hip replacement: a prospective study. J Bone Joint Surg [Am] 2003;85-A:1470–1478.
- 21.↑
Lim SJ Ko KR Park CW Moon YW Park YS . Robot-assisted primary cementless total hip arthroplasty with a short femoral stem: a prospective randomized short-term outcome study. Comput Aided Surg 2015;20:41–46.
- 22.↑
Nakamura N Sugano N Nishii T Miki H Kakimoto A Yamamura M . Robot-assisted primary cementless total hip arthroplasty using surface registration techniques: a short-term clinical report. Int J CARS 2009;4:157–162.
- 23.↑
Nakamura N Sugano N Nishii T Kakimoto A Miki H . A comparison between robotic-assisted and manual implantation of cementless total hip arthroplasty. Clin Orthop Relat Res 2010;468:1072–1081.
- 24.↑
Nishihara S Sugano N Nishii T Miki H Nakamura N Yoshikawa H . Comparison between hand rasping and robotic milling for stem implantation in cementless total hip arthroplasty. J Arthroplasty 2006;21:957–966.
- 25.↑
Siebel T Käfer W . [Clinical outcome following robotic assisted versus conventional total hip arthroplasty: a controlled and prospective study of seventy-one patients]. Z Orthop Ihre Grenzgeb 2005;143:391–398.
- 26.↑
Lewinnek GE Lewis JL Tarr R Compere CL Zimmerman JR . Dislocations after total hip-replacement arthroplasties. J Bone Joint Surg [Am] 1978;60-A:217–220.
- 27.↑
Callanan MC Jarrett B Bragdon CR, et al. The John Charnley Award: risk factors for cup malpositioning: quality improvement through a joint registry at a tertiary hospital. Clin Orthop Relat Res 2011;469:319–329.
- 28.↑
Abdel MP von Roth P Jennings MT Hanssen AD Pagnano MW . What safe zone? The vast majority of dislocated THAs are within the Lewinnek safe zone for acetabular component position. Clin Orthop Relat Res 2016;474:386–391.
- 29.↑
Reina N Putman S Desmarchelier R, et al; SFHG. Can a target zone safer than Lewinnek’s safe zone be defined to prevent instability of total hip arthroplasties? Case-control study of 56 dislocated THA and 93 matched controls. Orthop Traumatol Surg Res 2017;103:657–661.
- 30.↑
Tezuka T Heckmann ND Bodner RJ Dorr LD . Functional safe zone is superior to the Lewinnek safe zone for total hip arthroplasty: why the Lewinnek safe zone is not always predictive of stability. J Arthroplasty 2019;34:3–8.
- 31.↑
Barrack RL Krempec JA Clohisy JC, et al. Accuracy of acetabular component position in hip arthroplasty. J Bone Joint Surg Am 2013;95:1760–1768.
- 32.↑
Seagrave KG Troelsen A Malchau H Husted H Gromov K . Acetabular cup position and risk of dislocation in primary total hip arthroplasty. Acta Orthop 2017;88:10–17.
- 33.↑
Behery OA Poultsides L Vigdorchik JM . Modern imaging in planning a personalized hip replacement and evaluating the spino-pelvic relationship in prosthetic instability. In: Rivière C Vendittoli PA , eds. Personalized hip and knee joint replacement. Cham: Springer, 2020:143–156.
- 34.
Perticarini L Rossi SMP Benazzo F . Unstable total hip replacement: why? Clinical and radiological aspects. Hip Int 2020;30:37–41.
- 35.↑
Sultan AA Khlopas A Piuzzi NS Chughtai M Sodhi N Mont MA . The impact of spino-pelvic alignment on total hip arthroplasty outcomes: a critical analysis of current evidence. J Arthroplasty 2018;33:1606–1616.
- 36.↑
Redmond JM Gupta A Hammarstedt JE Petrakos AE Finch NA Domb BG . The learning curve associated with robotic-assisted total hip arthroplasty. J Arthroplasty 2015;30:50–54.
- 37.↑
Kong X Yang M Jerabek S Zhang G Chen J Chai W . A retrospective study comparing a single surgeon’s experience on manual versus robot-assisted total hip arthroplasty after the learning curve of the latter procedure: a cohort study. Int J Surg 2020;77:174–180.
