Aims

Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) have both been shown to be effective treatments for osteoarthritis (OA) of the knee. Many studies have compared the outcomes of the two treatments, but less so with the use of robotics, or individualized TKA alignment techniques. Functional alignment (FA) is a novel technique for performing a TKA and shares many principles with UKA. Our aim was to compare outcomes from a case-matched series of robotic-assisted UKAs and robotic-assisted TKAs performed using FA.

Aims. Robotic-assisted unicompartmental knee arthroplasty (R-UKA) has been proposed as an approach to improve the results of the conventional manual UKA (C-UKA). The aim of this meta-analysis was to analyze the studies comparing R-UKA and C-UKA in terms of clinical outcomes, radiological results, operating time, complications, and revisions. Methods. The literature search was conducted on three databases (PubMed, Cochrane, and Web of Science) on 20 February 2024 according to the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Inclusion criteria were comparative studies, written in the English language, with no time limitations, on the comparison of R-UKA and C-UKA. The quality of each article was assessed using the Downs and Black Checklist for Measuring Quality. Results. Among the 3,669 articles retrieved, 21 studies on 19 series of patients were included. A total of 3,074 patients (59.5% female and 40.5% male; mean age 65.2 years (SD 3.9); mean BMI 27.4 kg/m. 2. (SD 2.2)) were analyzed. R-UKA obtained a superior Knee Society Score improvement compared to C-UKA (mean difference (MD) 4.9; p < 0.001) and better Forgotten Joint Score postoperative values (MD 5.5; p = 0.032). The analysis of radiological outcomes did not find a statistically significant difference between the two approaches. R-UKA showed longer operating time (MD 15.6; p < 0.001), but reduced complication and revision rates compared to C-UKA (5.2% vs 10.1% and 4.1% vs 7.2%, respectively). Conclusion. This meta-analysis showed that the robotic approach for UKA provided a significant improvement in functional outcomes compared to the conventional manual technique. R-UKA showed similar radiological results and longer operating time, but reduced complication and revision rates compared to C-UKA. Overall, R-UKA seems to provide relevant benefits over C-UKA in the management of patients undergoing UKA. Cite this article: Bone Jt Open 2024;5(5):374–384

Robotic assistance in knee arthroplasty has become increasingly popular due to improved accuracy of prosthetic implantation. However, literature on the mid-term outcomes is limited especially that of hand-held robotic-assisted devices. We present one of the longest follow-up series to date using this novel technology and discuss the learning curve for introducing robotic technology into our practice. The purpose of this single-surgeon study is to evaluate the survival, patient-reported outcomes and learning curve for handheld boundary-controlled robotic-assisted unicompartmental knee arthroplasties (HBRUKAs) at our hospital. This retrospective study evaluates 100 cases (94 Medial, 6 Lateral) performed by a single surgeon between October 2012 and July 2018. 52% were males, mean age was 64.5y (range 47.3y-85.2y) and mean BMI was 31.3 (range 21.8–43). Both inlay (40%) and onlay (60%) designs were implanted. Patients were followed up routinely at 1 and 5 years with Oxford Knee Scores (OKS) recorded. The learning curve was determined by tourniquet times. At a mean follow-up of 4.3 years (range 1.6y–7.3y), survivorship was 97%. There were three revisions: One case of aseptic loosening (1.5y), one case of deep-infection (3.8y) and one case of contralateral compartment osteoarthritis progression (5y). Mean 5-year OKS was 39.8. A 14.3% reduction in mean tourniquet times between the first 25 cases (105.5minutes) and subsequent cases (90.4minutes) was seen. This single-surgeon study showed good survivorship and patient-reported outcomes for HBRUKAs at our hospital. A learning curve of approximately 25 cases was shown, with significant decreases in tourniquet times with respect to increased surgeon experience

Aims

The purpose of this study was to compare the radiological outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA).

Introduction

The purpose of this study was to compare the radiographic outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA).

Aims

The primary aim of the study was to compare the knee-specific functional outcome of robotic unicompartmental knee arthroplasty (rUKA) with manual total knee arthroplasty (mTKA) for the management of isolated medial compartment osteoarthritis. Secondary aims were to compare length of hospital stay, general health improvement, and satisfaction between rUKA and mTKA.

Aims. Robotic-assisted unicompartmental knee arthroplasty (UKA) promises accurate implant placement with the potential of improved survival and functional outcomes. The aim of this study was to present the current evidence for robotic-assisted UKA and describe the outcome in terms of implant positioning, range of movement (ROM), function and survival, and the types of robot and implants that are currently used. Materials and Methods. A search of PubMed and Medline was performed in October 2018 in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Search terms included “robotic”, “knee”, and “surgery”. The criteria for inclusion was any study describing the use of robotic UKA and reporting implant positioning, ROM, function, and survival for clinical, cadaveric, or dry bone studies. Results. A total of 528 articles were initially identified from the databases and reference lists. Following full text screening, 38 studies that satisfied the inclusion criteria were included. In all, 20 studies reported on implant positioning, 18 on functional outcomes, 16 on survivorship, and six on ROM. The Mako (Stryker, Mahwah, New Jersey) robot was used in 32 studies (84%), the BlueBelt Navio (Blue Belt Technologies, Plymouth, Minnesota) in three (8%), the Sculptor RGA (Stanmore Implants, Borehamwood United Kingdom) in two (5%), and the Acrobot (The Acrobot Co. Ltd., London, United Kingdom) in one study (3%). The most commonly used implant was the Restoris MCK (Stryker). Nine studies (24%) did not report the implant that was used. The pooled survivorship at six years follow-up was 96%. However, when assessing survival according to implant design, survivorship of an inlay (all-polyethylene) tibial implant was 89%, whereas that of an onlay (metal-backed) implant was 97% at six years (odds ratio 3.66, 95% confidence interval 20.7 to 6.46, p < 0.001). Conclusion. There is little description of the choice of implant when reporting robotic-assisted UKA, which is essential when assessing survivorship, in the literature. Implant positioning with robotic-assisted UKA is more accurate and more reproducible than that performed manually and may offer better functional outcomes, but whether this translates into improved implant survival in the mid- to longer-term remains to be seen. Cite this article: Bone Joint J 2019;101-B:838–847

Introduction. Existing studies report more accurate implant placement with robotic-assisted unicompartmental knee arthroplasty (UKA); however, surgeon experience has not always been accounted for. The purpose of this study was to compare the accuracy of an experienced, high-volume surgeon to published data on robotic-assisted UKA tibial component alignment. Methods. One hundred thirty-one consecutive manual UKAs performed by a single surgeon using a cemented, fixed bearing implant were radiographically reviewed by an independent reviewer to avoid surgeon bias. Native and tibial implant slope and coronal alignment were measured on pre- and postoperative lateral and anteroposterior radiographs, respectively. Manual targets were set within 2° of native tibial slope and 0 to 2° varus tibial component alignment. Deviations from target were calculated as root mean square (RMS) errors and were compared to robotic-assisted UKA data. Results. One hundred twenty-eight UKAs were analyzed. The proportion of manual UKAs within the target for tibial component alignment (66%) exceeded published values comparing robotic (58%) to manual (41%) UKA. RMS error for tibial component alignment (1.5°) was less than published RMS error rates in robotic UKAs (range 1.8 to 5°). Fifty-eight percent of study UKAs were within the surgeon's preoperative goal for tibial slope, closer to published findings of 80% for robotic UKAs vs. 22% of manual UKAs. RMS error for tibial slope in study UKAs (1.5°) was smaller than RMS error rates for tibial slope in robotic UKAs (range 1.6 to 1.9°). Conclusion. These data demonstrate that an experienced, high-volume surgeon's accuracy in manual UKA can meet or exceed robotic-assisted UKA. Therefore, a surgeon's experience and aptitude should be taken into account when determining the value of robotics in knee arthroplasty. Further, the relationship between implant position and patient outcomes, and consensus on ideal surgical targets for optimal survivorship need further elucidation

INTRODUCTION

Medial and lateral unicompartmental knee arthroplasty (UKA) are both reliable treatment options for isolated osteoarthritis. Postoperative lower leg alignment is known to play an important role on short-term functional outcomes, which is an important argument for the use of robotic-assisted surgery. Since several anatomical and kinematic differences exist between both compartments, it seems inaccurate to aim for similar postoperative lower leg alignment in medial and lateral UKA. Purpose of this study was (I) to compare outcomes between both procedures and (II) to assess the role of preoperative and postoperative alignment on short-term outcomes in both procedures.

Unicompartmental knee arthroplasty is realizing a resurgence due to factors such as improved alignment and sizing of components during surgery. This study compares the early results of two implantation techniques – robotic-assisted and standard manual alignment guides – to evaluate how a new technology developed to improve accuracy affects early patient outcomes. For this study, we chose a prospective consecutive series of 20 patients in each group to receive a medial unicompartmental knee arthroplasty. The patients were evaluated clinically using standard outcomes measures (Knee Society, WOMAC and Oxford scores) as well as for modes of failure. Average follow-up for the manual onlay technique was 12 months and for the robotic-assisted inlay technique was and 10 months. Patients were not statistically different in terms of BMI, age, or diagnosis (p> 0.05). Knee society score (p=0.65), total WOMAC score (p=0.75) and Oxford knee score (p=0.88) were not statistically different between the three groups. Five patients in the robotic-assisted inlay group complained of persistent tibial pain that resolved in four patients. There were no revisions for the manual onlay implant group and there was one revision for persistent tibial pain in the robotic-assisted inlay group, consisting of a conversion to a standard manual onlay UKA tibial component. Patient outcomes were similar with inlay robotic-assisted unicompartmental knee arthroplasty compared with conventional manual onlay implant techniques. Roboticassisted inlay components resulted in slightly increased complaints of tibial pain and had one revision for tibial pain, however the revision was to a standard onlay UKA tibial component