How should we evaluate robotics in the operating theatre?

Robotic trials in arthroplasty surgery

Total hip and knee arthroplasty (THA, TKA) are largely successful procedures; however, both have variable outcomes, resulting in some patients being dissatisfied with the outcome. Surgeons are turning to technologies such as robotic-assisted surgery in an attempt to improve outcomes. Robust studies are needed to find out if these innovations are really benefitting patients. The Robotic Arthroplasty Clinical and Cost Effectiveness Randomised Controlled Trials (RACER) trials are multicentre, patient-blinded randomized controlled trials. The patients have primary osteoarthritis of the hip or knee. The operation is Mako-assisted THA or TKA and the control groups have operations using conventional instruments. The primary clinical outcome is the Forgotten Joint Score at 12 months, and there is a built-in analysis of cost-effectiveness. Secondary outcomes include early pain, the alignment of the components, and medium- to long-term outcomes. This annotation outlines the need to assess these technologies and discusses the design and challenges when conducting such trials, including surgical workflows, isolating the effect of the operation, blinding, and assessing the learning curve. Finally, the future of robotic surgery is discussed, including the need to contemporaneously introduce and evaluate such technologies.

Robotic-assisted TKA is Not Associated With Decreased Odds of Early Revision: An Analysis of the American Joint Replacement Registry

BACKGROUND

Robotic-assisted TKA continues to see wider clinical use, despite limited knowledge of its impact on patient satisfaction and implant survival. Most studies to date have presented small cohorts and came from single-surgeon or single-center experiences. Therefore, a population-level comparison of revision rates between robotic-assisted and conventional TKA in the registry setting may help arthroplasty surgeons better define whether robotic assistance provides a meaningful advantage compared with the conventional technique.

QUESTIONS/PURPOSES

(1) After controlling for confounding variables, such as surgeon, location of surgery, and patient comorbidity profile, were robotic-assisted TKAs less likely than conventional TKAs to result in revision for any reason at 2 years? (2) After again controlling for confounding variables, were robotic-assisted TKAs less likely to result in any specific reasons for revision than the conventional technique at 2 years?

METHODS

The American Joint Replacement Registry was used to identify patients 65 years or older who underwent TKA between January 2017 and March 2020 with a minimum of 2 years of follow-up. Patients were limited to age 65 yeas or older to link TKAs to Medicare claims data. Two retrospective cohorts were created: robotic-assisted TKA and conventional TKA. Patient demographic variables included in the analysis were age, gender, BMI, and race. Additional characteristics included the Charlson comorbidity index, anesthesia type, year of the index procedure, and length of stay. A total of 10% (14,216 of 142,550) of TKAs performed during this study period used robotics. Patients with robotic-assisted TKA and those with conventional TKA were similar regarding age (73 ± 6 years versus 73 ± 6 years; p = 0.31) and gender (62% [8736 of 14,126] versus 62% [79,399 of 128,334] women; p = 0.34). A multivariable, mixed-effects logistic regression model was created to analyze the odds of all-cause revision as a factor of robot use, and a logistic regression model was created to investigate specific revision diagnoses.

RESULTS

After controlling for potentially confounding variables, such as surgeon, location of surgery, and Charlson comorbidity index, we found no difference between the robotic-assisted and conventional TKAs in terms of the odds of revision at 2 years (OR of robotic-assisted versus conventional TKA 1.0 [95% CI 0.8 to 1.3]; p = 0.92). The reasons for revision of robotic-assisted TKA did not differ from those of conventional TKA, except for an increased odds of instability (OR 1.6 [95% CI 1.0 to 2.4]; p = 0.04) and pain (OR 2.1 [95% CI 1.4 to 3.0]; p < 0.001) in the robotic-assisted cohort.

CONCLUSION

In light of these findings, surgeons should not assume that robotic assistance in TKA will lead to improved early implant survival. Our findings do not support an improvement over conventional TKA with robotic assistance with regards to common causes of early revisions such malalignment, malposition, stiffness, pain, and instability, and in some cases, suggest there is a benefit to conventional TKA. Differences in the mid-term and long-term revision risk with conventional versus robotic-assisted TKA remain unknown. Appropriate informed consent around the use of robotic assistance should not imply decreased early revision risk.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Robotic-arm assisted unicompartmental knee arthroplasty system has a learning curve of 11 cases and increased operating time

PURPOSE

UKA has higher revision risk, particularly for lower volume surgeons. While robotic-arm assisted systems allow for increased accuracy, introduction of new systems has been associated with learning curves. The aim of this study was to determine the learning curve of a UKA robotic-arm assisted system. The hypothesis was that this may affect operative times, patient outcomes, limb alignment, and component placement.

METHODS

Between 2017 and 2021, five surgeons performed 152 consecutive robotic-arm assisted primary medial UKA, and measurements of interest were recorded. Patient outcomes were measured with Oxford Knee Score, EuroQol-5D, and Forgotten Joint Score at 6 weeks, 1 year, and 2 years. Surgeons were grouped into 'low' and 'high' usage groups based on total UKA (manual and robotic) performed per year.

RESULTS

A learning curve of 11 cases was found with operative time (p < 0.01), femoral rotation (p = 0.02), and insert sizing (p = 0.03), which highlighted areas that require care during the learning phase. Despite decreased 6-week EQ-5D-5L VAS in the proficiency group (77 cf. 85, p < 0.01), no difference was found with implant survival (98.2%) between phases (p = 0.15), or between 'high' and 'low' usage surgeons (p = 0.23) at 36 months. This suggested that the learning curve did not lead to early adverse effects in this patient cohort.

CONCLUSION

Introduction of a UKA robotic-arm assisted system showed learning curves for operative times and insert sizing but not for implant survival at early follow-up. The short learning curve regardless of UKA usage indicated that robotic-arm assisted UKA may be particularly useful for low-usage surgeons.

LEVEL OF EVIDENCE

Level III, Retrospective cohort study.

How long does image based robotic total knee arthroplasty take during the learning phase? Analysis of the key steps from the first fifty cases

INTRODUCTION

Robotically assisted total knee arthroplasty (RA-TKA) is an emerging surgical tool. The purpose of this study was to analyze the length of time taken to perform the key steps of a RA-TKA for a surgeon and centre new to the MAKO robotic system.

METHOD

This was a prospective cohort study of the first 50 patients undergoing TKA using a robotic platform (Mako, Stryker, Kalamazoo, MI, USA) performed by a single surgeon. Each key surgical step was recorded. The first 50 patients were chronologically allocated into five groups of ten and compared.

RESULTS

Mean operation length was 59.4 ± 7.4 min with significant improvement after 30 cases. A significant effect on certain steps of the surgery also occurred over 50 cases: after 30 cases for pre-operative planning (3.8 min in group 1 versus 1.2 min in group 4, p < 0.005), ten cases for registration time (5.2 min in group 1 versus 3.8 in group 2, p = 0.039) and ten cases for tibial cutting time (1.6 min in group 1 versus 1.3 in group 2, p < 0.005). Nurse setup, femur cutting, and intraoperative planning did not demonstrate a significant improvement in time over 50 cases.

CONCLUSION

A significant decrease in total operating length occurred after the 30th case. Anatomical registration and tibial cutting time demonstrated the largest improvements. MAKO image-based robotically assisted TKA is not a time-intensive intervention for both the surgeon and scrub nursing staff, and significant improvements in total surgical time occurs early in the learning phase.

The learning curve of imageless robot-assisted total knee arthroplasty with standardised laxity testing requires the completion of nine cases, but does not reach time neutrality compared to conventional surgery

PURPOSE

The assistance of robot technology is introduced into the operating theatre to improve the precision of a total knee arthroplasty. However, as with all new technology, new technology requires a learning curve to reach adequate proficiency. The primary aim of this study was to identify the learning curve of an imageless robotic system with standardised laxity testing. The secondary aim of this study was to evaluate the accuracy of the intra-operative coronal alignment during the learning curve.

METHODS

A prospective study was performed on 30 patients undergoing robot-assisted total knee arthroplasty with an imageless robotic system (Corin, Massachusetts, USA) associated with a dedicated standardised laxity testing device. The learning curve of all surgical steps was assessed with intra-operative video monitoring. As comparison, the total surgical time of the last 30 patients receiving conventional total knee arthroplasty by the same surgeon and with the same implant was retrospectively assessed. Coronal lower limb alignment was evaluated pre- and post-operatively on standing full-leg radiographs.

RESULTS

CUSUM (cumulative summation) analysis has shown inflexion points in multiple steps associated with robot-assisted surgery between one and 16 cases, which indicates the progression from the learning phase to the proficiency phase. The inflexion point for total operative time occurred after nine cases. Robot-assisted total knee surgery required significantly longer operative times than the conventional counterpart, with an average increase of 22 min. Post-operative limb and implant alignment was not influenced by a learning curve.

CONCLUSION

The introduction of an imageless robotic system with standardised laxity assessment for total knee arthroplasty results in a learning curve of nine cases based on operative time. Compared to conventional surgery, the surgeon is not able to reach time neutrality with the robotic platform. There is no learning curve associated with coronal limb or implant alignment. This study enables orthopaedic surgeons to understand the implementation of this surgical system and its specific workflow into clinical practice.

The Ability of Robot-Assisted Total Knee Arthroplasty in Matching the Efficiency of Its Conventional Counterpart at an Orthopaedic Specialty Hospital

BACKGROUND

Robot-assisted total knee arthroplasty (RA-TKA) has become a popular technology. Studies have investigated the learning curve for surgeons incorporating RA-TKA into practice, but less is known regarding the change in operative efficiency when introducing RA-TKA into a facility. The purpose of this study was to investigate the effects of RA-TKA on operative and turnover time at an orthopaedic specialty hospital.

METHODS

A total of 148 cases (74 RA-TKA and 74 conventional TKA [C-TKA]) performed by 2 surgeons with previous robotic experience were identified following the introduction of RA-TKA at our facility. Patient demographics, comorbidities, and operative times (ie, wheels-in to incision, incision to closure, closure to wheels-out, and turnover time) were recorded. Cumulative summation analyses were used to investigate learning curves of factors extraneous to surgeon proficiency with RA-TKA.

RESULTS

While RA-TKA had a slightly longer set up (3 minutes; range, 12-45), surgical (5 minutes; range, 33-118), and breakdown time (3 minutes; range, 2-7), there was no difference in turnover time between the groups. The learning curve for surgeon A was 6 robotic cases, whereas surgeon B demonstrated no learning curve. There was no identifiable learning curve for turnover time.

CONCLUSION

There was a mean of 8 minutes of increased time required to perform a RA-TKA compared to C-TKA. However, these small increases for the RA-TKA group for set-up, surgical, and breakdown times are not likely to be clinically relevant compared to the C-TKA. It appears that the RA-TKA technology was able to be incorporated into this specialty hospital with minimal changes to surgical efficiency.

The learning curve in robotic assisted knee arthroplasty is flattened by the presence of a surgeon experienced with robotic assisted surgery

PURPOSE

The purpose of this study was to investigate the learning curve associated with robotic assisted knee arthroplasty (RAS KA). Therefore, the evaluation of the influence of an experienced surgeon on the overall team performance of three surgeons regarding the learning curve in RAS KA was investigated. It was hypothesized that the presence of an experienced surgeon flattens the learning curve and that there was no inflection point for the learning curve of the surgical team.

METHODS

Fifty-five cases consisting of 31 total knee arthroplasties (TKA) and 24 unicompartmental arthroplasties (UKA) performed by three surgeons during 2021 were prospectively investigated. Single surgeon and team performance for operation time learning curve and inflection points were investigated using cumulative sum analysis (CUSUM).

RESULTS

A downward trend line for individual surgeons and the team performance regarding the operation time learning curve was observed. No inflexion point was observed for the overall team performance regarding TKA and UKA. The surgeon that performed all cases with the assistance of the experienced surgeon had significantly shorter surgical times than the surgeon that only occasionally received assistance from the experienced surgeon (p = 0.004 TKA; p = 0.002 UKA).

CONCLUSION

The presence of an experienced surgeon in robotically assisted knee arthroplasty can flatten the learning curve of the surgical team formerly unexperienced in robotic assisted systems. Manufacturers should provide expanded support during initial cases in centres without previous experience to robotic assisted knee arthroplasty.

LEVEL OF EVIDENCE

III.

Comparative assessment of current robotic-assisted systems in primary total knee arthroplasty

Robotic-assisted total knee arthroplasty (TKA) has proven higher accuracy, fewer alignment outliers, and improved short-term clinical outcomes when compared to conventional TKA. However, evidence of cost-effectiveness and individual superiority of one system over another is the subject of further research. Despite its growing adoption rate, published results are still limited and comparative studies are scarce. This review compares characteristics and performance of five currently available systems, focusing on the information and feedback each system provides to the surgeon, what the systems allow the surgeon to modify during the operation, and how each system then aids execution of the surgical plan.Cite this article: Bone Jt Open 2023;4(1):13-18.

The Impact of COVID-19 on Total Joint Arthroplasty Fellowship Training

BACKGROUND

COVID-19 created unprecedented challenges in surgical training especially in specialties with high elective case volume. We hypothesized that case volume during total joint arthroplasty fellowship training would decrease by 25% given widespread economic shutdowns encountered during the fourth quarter of the 2019-2020 academic year.

METHODS

Case logs from the Accreditation Council for Graduate Medical Education were obtained for accredited total joint arthroplasty fellowships (2017-2018 to 2020-2021). Case volumes were extracted and summarized as means ± SD. Student's t tests were used for inter-year comparisons.

RESULTS

One hundred and eighty three arthroplasty fellows from 24 accredited fellowships were included. There was a 14% year-over-year decrease in total case volume during the 2019-2020 academic year (390 ± 108 vs 453 ± 128, P < .001). Case volume rebounded during the 2020-2021 academic year to 465 ± 93 (19% increase, P < .001). Case categories with the most significant percentage declines in 2019-2020 were primary total knee arthroplasty (TKA, -23%), revision total hip arthroplasty (THA, -19%), revision TKA (rTKA, -11%), and primary THA (-10%).

CONCLUSION

There was a 14% overall decrease in arthroplasty case volume during the 2019-2020 academic year, which correlated with the widespread economic shutdowns during the COVID-19 pandemic. Certain elective case categories like primary TKA experienced the greatest negative impact. Results from this study may inform prospective trainees and faculty during future national emergencies.

Tourniquet use in total knee arthroplasty and the risk of infection: a meta-analysis of randomised controlled trials

Purpose

The intra-operative use of tourniquets during Total Knee Arthroplasty (TKA) is common practice. The advantages of tourniquet use include decreased operating time and the creation of a bloodless visualisation field. However, tourniquet use has recently been linked with increased post-operative pain, reduced range of motion, and slower functional recovery. Importantly, there is limited evidence of the effect of tourniquet use on infection risk. The purpose of this systematic review and meta-analysis is to fill this gap in the literature by synthesising data pertaining to the association between tourniquet use and infection risk in TKA.

Methods

A systematic literature search was performed on Pubmed, Embase, Cochrane and clinicaltrials.gov up to May 2021. Randomized control trials were included, comparing TKA outcomes with and without tourniquet use. The primary outcome was overall infection rate. Secondary outcomes included superficial and deep infection, skin necrosis, skin blistering, DVT rate, and transfusion rate.

Results

14 RCTs with 1329 patients were included. The pooled incidence of infection in the tourniquet group (4.0%, 95% CI = 2.7–5.4) was significantly higher compared to the non-tourniquet group (2.0%, 95% CI = 1.1–3.1) with an OR of 1.9 (95% CI = 1.1–3.76, p = 0.03). The length of hospital stay, haemoglobin drop (0.33 95% CI =0.12–0.54), P = 0.002) and transfusion rates (OR of 2.7, 95%CI = 1.4–5.3, P = < 0.01) were higher in the tourniquet group than the non-tourniquet group. The difference in the length of inhospital stay was 0.24 days favouring the non-tourniquet group (95% CI = 0.10–0.38, P = < 0.01). The incidence of skin blistering (OR 2.6, 95% CI = 0.7–9.9, p = 0.17), skin necrosis (OR 3.0, 95% CI = 0.50–19.3, p = 0.25), and DVT rates (OR 1.5, 95% CI = 0.60–3.60, p = 0.36) did not differ between the two groups.

Conclusion

Quantitative synthesis of the data suggested tourniquet use was associated with an increased overall risk of infection, intraoperative blood loss, need for blood transfusion and longer hospital stay. Findings of this meta-analysis do not support the routine use of tourniquet in TKA and arthroplasty surgeons should consider any potential additional risks associated with its use.

Level of evidence

meta-analysis, Level II.

Comparison of serum inflammatory indicators and radiographic results in MAKO robotic-assisted versus conventional total knee arthroplasty for knee osteoarthritis: a retrospective study of Chinese patients

BACKGROUND

The purpose of this study was to compare the serum inflammatory indicators and radiographic results of conventional manual total knee arthroplasty (CM-TKA) with those of MAKO-robotic assisted total knee arthroplasty (MA-TKA).

METHODS

We retrospectively analysed 65 patients with knee osteoarthritis who underwent unilateral TKA from December 2020 to November 2021 in our department, which included 34 patients who underwent MA-TKA and 31 patients who underwent CM-TKA. The tourniquet time and estimated blood loss (EBL) were compared between the two groups. Knee function was evaluated using range of motion (ROM), functional score and pain score. Leukocytes, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), creatine kinase (CK), and neutrophil-to-lymphocyte ratio (NLR) were recorded at 3 time points (preoperative, and on the first and third postoperative days). The hip-knee-ankle angle (HKA) and the femoral and tibial component angles in the coronal and sagittal planes were used for postoperative radiographic evaluation.

RESULTS

The postoperative MA-TKA group had less EBL (496.9 ± 257.8 vs. 773.0 ± 301.3 ml, p < 0.001). There was no significant difference in knee function scores at 6 weeks postoperatively (p > 0.05). IL-6 levels were significantly lower in the MA-TKA group on the 1st postoperative day (11.4 (5.2, 21.0) vs. 24.6 (86.3, 170.8), p = 0.031). This difference in inflammatory indices became more pronounced at 72 hours after the operation because CRP, ESR, IL-6, and CK values were significantly lower in the MA-TKA group on the 3rd postoperative day (72 h) (p < 0.05). Postoperative radiographic examinations performed 2 days after the MA-TKA group suggested that only 2 cases of HKA had outlier values, which was remarkably better than the 12 cases found in the CM-TKA group (5.9% vs. 38.7%, p < 0.001). The frontal femoral component was significantly closer to the expected value of 90° in the MA-TKA group (90.9 (90.5, 92.3) vs. 92.4 (91.3, 93.7), p = 0.031). The remaining imaging evaluation parameters were not significantly different between the two groups (p > 0.05).

CONCLUSIONS

In Chinese patients with OA, there was a milder systemic inflammatory response in the early postoperative period after MA-TKA compared to that of CM-TKA, as well as better radiographic outcomes. However, the tourniquet time was prolonged, and no advantages were observed in terms of functional score or pain score in the short-term follow-up.

Robot-assisted total knee arthroplasty is associated with a learning curve for surgical time but not for component alignment, limb alignment and gap balancing

PURPOSE

The application of robotics in the operating theatre for total knee arthroplasty (TKA) remains controversial. As with all new technology, the introduction of new systems is associated with a learning curve and potentially associated with extra complications. Therefore, the aim of this study is to identify and predict the learning curve of robot-assisted (RA) TKA.

METHODS

A RA TKA system (MAKO) was introduced in April 2018 in our service. A retrospective analysis was performed of all patients receiving a TKA with this system by six surgeons. Operative times, implant and limb alignment, intraoperative joint balance and robot-related complications were evaluated. Cumulative summation (CUSUM) analyses were used to assess learning curves for operative time, implant alignment and joint balance in RA TKA. Linear regression was performed to predict the learning curve of each surgeon.

RESULTS

RA TKA was associated with a learning curve of 11-43 cases for operative time (p < 0.001). This learning curve was significantly affected by the surgical profile (high vs. medium vs. low volume). A complete normalisation of operative times was seen in four out of five surgeons. The precision of implant positioning and gap balancing showed no learning curve. An average deviation of 0.2° (SD 1.4), 0.7° (SD 1.1), 1.2 (SD 2.1), 0.2° (SD 2.9) and 0.3 (SD 2.4) for the mLDFA, MPTA, HKA, PDFA and PPTA from the preoperative plan was observed. Limb alignment showed a mean deviation of 1.2° (SD 2.1) towards valgus postoperatively compared to the intraoperative plan. One tibial stress fracture was seen as a complication due to suboptimal positioning of the registration pins.

CONCLUSION

RA TKA is associated with a learning curve for surgical time, which might be longer than reported in current literature and dependent on the profile of the surgeon. There is no learning curve for component alignment, limb alignment and gap balancing.

LEVEL OF EVIDENCE

IV.

Adapting non-medical applications for medical use: Ethical limits, coverage, and validation

The widespread adoption of smartphones and other mobile devices amongst healthcare providers opened new possibilities arising from the use of non-medical apps, social media, meeting platforms, and non-medical devices with intended medical purposes, thus expanding the communication and imaging chat systems between these professionals and their patients, as well as amongst healthcare professionals. However, adapting non-medical applications, social media, videoconference platforms and devices for medical use present potential limitations, barriers, and risks, which should be fully recognized to reduce crossing the fine line between ethical and unethical. In the herein study, we analyse the ethical limits, coverage, and validation of non-medical applications adapted for medical use. Level of evidence: IV (evidence from well-designed case-control or cohort studies).

Impact of intra-operative predictive ligament balance on post-operative balance and patient outcome in TKA: a prospective multicenter study

INTRODUCTION

New technologies exist which may assist surgeons to better predict final intra-operative joint balance. Our objectives were to compare the impact of (1) a predictive digital joint tensioning tool on intra-operative joint balance; and (2) joint balance and flexion joint laxity on patient-reported outcomes.

MATERIALS AND METHODS

Two-hundred Eighty patients received posterior cruciate ligament sacrificing TKA with ultra-congruent tibial inserts using a robotic-assisted navigation platform. Patients were divided into those in which a Predictive Plan with a digital joint-tensioning device was used (PP) and those in which it was not (NPP), in all cases final post-operative joint gaps were collected immediately before final implantation. Demographics and KOOS were collected pre-operatively. KOOS, complications and satisfaction were collected at 3, 6 and 12 months post-operatively. Optimal balance difference between PP and NPP was defined and compared using area-under-the-curve analysis (AUC). Outcomes were then compared according to the results from the AUC.

RESULTS

AUC analysis yielded a balance threshold of 1.5 mm, in which the PP group achieved a higher rate of balance throughout flexion compared to the NPP group: extension: 83 vs 52%; Midflexion: 82 vs 55%; Flexion 89 vs 68%; Flexion to Extension 80 vs 49%; p ≤ 0.003. Higher KOOS scores were observed in knees balanced within 1.5 mm across all sub-scores at various time points, however, differences did not exceed the minimum clinically important difference (MCID). Patients with > 1.5 mm flexion laxity medially or laterally had an increased likelihood of 2.2 (1.1-4.4) and 2.5 (1.3-4.8), respectively, for failing to achieve the Patient Acceptable Symptom State for KOOS Pain at 12 months. Patient satisfaction was high in both the PP and NPP groups (97.4 and 94.7%, respectively).

CONCLUSIONS

Use of a predictive joint tensioning tool improved the final balance in TKA. Improved outcomes were found in balanced knees; however, this improvement did not achieve the MCID, suggesting further studies may be required to define optimal balance targets. Limiting medial and lateral flexion laxity resulted in an increased likelihood of achieving the Patient Acceptable Symptom State for KOOS Pain.

Nursing considerations for patients undergoing robotic-arm assisted joint replacements

Robotic-arm assisted arthroplasty (RAA) has gained popularity over the past decade because of its ability to provide more accurate implant positioning with less surgical trauma than conventional manual arthroplasty. It has shown better early functional outcomes, less postoperative pain and shorter inpatient stays. A multidisciplinary approach is crucial in improving overall outcomes and ensuring this technology is implemented efficiently and safely, but there is limited published literature on the nursing considerations for managing patients undergoing RAA. This article aims to provide a pragmatic approach for nursing care in the pre-, intra-, and postoperative phases of RAA.

What is the evidence for clinical use of advanced technology in unicompartmental knee arthroplasty?

BACKGROUND

With an aim of improving prosthesis survivorship of unicompartmental knee arthroplasty (UKA), use of computer-assisted technologies (CATs) such as robotics, has been on the rise to reduce intraoperative errors in surgical technique. In light of recent influx of CATs in the UKA, a review of these innovations will help providers to understand their clinical utility.

METHOD

A systematic literature search was performed following Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines.

RESULTS

Among 19 studies comparing robot-assisted UKA with conventional UKA, only 32% were randomized control trials, 47% reported minimum mean follow-up of 2 years, and 21% evaluated prosthesis survival. Similar results were obtained for navigation-assisted UKA and UKA performed with patient-specific instrumentation.

CONCLUSION

While CATs seem to reduce the surgical errors in UKA, the evidence on the efficacy of any of the studied CATs to improve survivorship remains limited and there are issues related to cost-effectiveness, learning curve, and increase in operating time.

Advances and innovations in total hip arthroplasty

Total hip arthroplasty (THA) has been quoted as one of the most successful and cost-effective procedures in Orthopaedics. The last decade has seen an exponential rise in the number of THAs performed globally and a sharp increase in the percentage of young patients hoping to improve their quality of life and return to physically demanding activities. Hence, it is imperative to review the various applications of technology in total hip arthroplasty for improving outcomes. The development of state-of-the-art robotic technology has enabled more reproducible and accurate acetabular positioning, while long-term data are needed to assess its cost-effectiveness. This opinion piece aims to outline and present the advances and innovations in total hip arthroplasty, from virtual reality and three-dimensional printing to patient-specific instrumentation and dual mobility bearings. This illustrates and reflects the debate that will be at the centre of hip surgery for the next decade.

Alignment of the hindfoot in total knee arthroplasty: a systematic review of clinical and radiological outcomes

AIMS

Patients with a deformity of the hindfoot present a particular challenge when performing total knee arthroplasty (TKA). The literature contains little information about the relationship between TKA and hindfoot alignment. This systematic review aimed to determine from both clinical and radiological studies whether TKA would alter a preoperative hindfoot deformity and whether the outcome of TKA is affected by the presence of a postoperative hindfoot deformity.

METHODS

A systematic literature search was performed in the databases PubMed, EMBASE, Cochrane Library, and Web of Science. Search terms consisted of "total knee arthroplasty/replacement" combined with "hindfoot/ankle alignment". Inclusion criteria were all English language studies analyzing the association between TKA and the alignment of the hindfoot, including the clinical or radiological outcomes. Exclusion criteria consisted of TKA performed with a concomitant extra-articular osteotomy and case reports or expert opinions. An assessment of quality was conducted using the modified Methodological Index for Non-Randomized Studies (MINORS). The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered in the PROSPERO database (CRD42019106980).

RESULTS

A total of 17 studies were found to be eligible for review. They included six prospective and ten retrospective studies, and one case-control study. The effects of TKA showed a clinical improvement in the hindfoot deformity in three studies, but did not if there was osteoarthritis (OA) of the ankle (one study) or a persistent deformity of the knee (one study). The radiological alignment of the hindfoot corrected in 11 studies, but did not in the presence of a rigid hindfoot varus deformity (in two studies). The effects of a hindfoot deformity on TKA included a clinical association with instability of the knee in one study, and a shift in the radiological weightbearing axis in two studies. The mean MINORS score was 9.4 out of 16 (7 to 12).

CONCLUSION

TKA improves both the function and alignment of the hindfoot in patients with a preoperative deformity of the hindfoot. This may not apply if there is a persistent deformity of the knee, a rigid hindfoot varus deformity, or OA of the ankle. Moreover, a persistent deformity of the hindfoot may adversely affect the stability and longevity of a TKA. These findings should be interpreted with caution due to the moderate methodological quality of the studies which were included. Therefore, further prospective studies are needed in order to determine at which stage correction of a hindfoot deformity is required to optimize the outcome of a TKA. Cite this article: Bone Joint J 2021;103-B(1):87-97.