Early outcomes after robotic arm-assisted bi-unicompartmental knee arthroplasty compared with total knee arthroplasty: a prospective, randomized controlled trial

Abstract

Aims The aim of this study was to compare the clinical outcomes of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) during the first six weeks and at one year postoperatively. Methods A per protocol analysis of 76 patients, 43 of whom underwent TKA and 34 of whom underwent bi-UKA, was performed from a prospective, single-centre, randomized controlled trial. Diaries kept by the patients recorded pain, function, and the use of analgesics daily throughout the first week and weekly between the second and sixth weeks. Patient-reported outcome measures (PROMs) were compared preoperatively, and at three months and one year postoperatively. Data were also compared longitudinally and a subgroup analysis was conducted, stratified by preoperative PROM status. Results Both operations were shown to offer comparable outcomes, with no significant differences between the groups across all timepoints and outcome measures. Both groups also had similarly low rates of complications. Subgroup analysis for preoperative psychological state, activity levels, and BMI showed no difference in outcomes between the two groups. Conclusion Robotic arm-assisted, cruciate-sparing bi-UKA offered similar early clinical outcomes and rates of complications to a mechanically aligned TKA, both in the immediate postoperative period and up to one year following surgery. Further work is required to identify which patients with osteoarthritis of the knee will derive benefit from a cruciate-sparing bi-UKA. Cite this article: Bone Joint J 2021;103-B(10):1561–1570.

The risk of tibial eminence avulsion fracture with bi-unicondylar knee arthroplasty

“… 36 As such, the results of this study may overestimate the risk of ACL avulsion compared to that which might be expected in robot-assisted Bi-UKA, for which there has been a growing interest. 14 , 44 …”

“…36 As such, the results of this study may overestimate the risk of ACL avulsion compared to that which might be expected in robot-assisted Bi-UKA, for which there has been a growing interest. 14,44 The models used for this research were originally developed and validated for UKA-M under compressive loading, for medial cortical strains distal to the implant and bone-implant micromotions. It was assumed that the utility of this model could be extended to also include UKA-L, with an additional tensile ACL load applied, and examining regions of interest closer to the implants.…”

Is the die cast? Anterior cruciate ligament injury and osteoarthritis

“…1 The importance of the ACL is such that many research workers are looking at preserving it in arthroplasty of the knee, either through the use of compartmental arthroplasty, [3][4][5][6][7][8] or through bicruciateretaining total knee arthroplasty (TKA). [9][10][11][12][13][14] Rupture of the ACL was initially described by Robert Adams in 1837, and the first ACL repair was reported by Mayo Robson of Leeds in 1895. 15 In 1967, Lemaire 16,17 described reconstruction using an anterolateral tenodesis with fascia lata.…”

The International Hip Society Meeting 2021

“…8 It is really good to see this addition to the increasing number of randomized studies in knee arthroplasty surgery. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Colleagues in trauma surgery are also making good use of registry data when looking at mortality, 26 and after rarer procedures, such as distal femoral arthroplasty for fracture. 27 This provides useful, albeit incomplete, information and will guide our practice and generate questions that can be addressed in future studies.…”