Sagittal plane imbalance (SPI), or asymmetry between extension and flexion gaps, is an important issue in total knee arthroplasty (TKA). The purpose of this study was to compare SPI between kinematic alignment (KA), mechanical alignment (MA), and functional alignment (FA) strategies. In 137 robotic-assisted TKAs, extension and flexion stressed gap laxities and bone resections were measured. The primary outcome was the proportion and magnitude of medial and lateral SPI (gap differential > 2.0 mm) for KA, MA, and FA. Secondary outcomes were the proportion of knees with severe (> 4.0 mm) SPI, and resection thicknesses for each technique, with KA as reference.Aims
Methods
The aims of this study were: 1) to describe extended restricted kinematic alignment (E-rKA), a novel alignment strategy during robotic-assisted total knee arthroplasty (RA-TKA); 2) to compare residual medial compartment tightness following virtual surgical planning during RA-TKA using mechanical alignment (MA) and E-rKA, in the same set of osteoarthritic varus knees; 3) to assess the requirement of soft-tissue releases during RA-TKA using E-rKA; and 4) to compare the accuracy of surgical plan execution between knees managed with adjustments in component positioning alone, and those which require additional soft-tissue releases. Patients who underwent RA-TKA between January and December 2022 for primary varus osteoarthritis were included. Safe boundaries for E-rKA were defined. Residual medial compartment tightness was compared following virtual surgical planning using E-rKA and MA, in the same set of knees. Soft-tissue releases were documented. Errors in postoperative alignment in relation to planned alignment were compared between patients who did (group A) and did not (group B) require soft-tissue releases.Aims
Methods
This systematic review and meta-analysis aimed to compare the influence of patellar resurfacing following cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) on the incidence of anterior knee pain, knee-specific patient-reported outcome measures, complication rates, and reoperation rates. A systematic review of MEDLINE, PubMed, and Google Scholar was performed to identify randomized controlled trials (RCTs) according to search criteria. Search terms used included: arthroplasty, replacement, knee (Mesh), TKA, prosthesis, patella, patellar resurfacing, and patellar retaining. RCTs that compared patellar resurfacing versus unresurfaced in primary TKA were included for further analysis. Studies were evaluated using the Scottish Intercollegiate Guidelines Network assessment tool for quality and minimization of bias. Data were synthesized and meta-analysis performed.Aims
Methods
We have previously reported the mid-term outcomes of revision total knee arthroplasty (TKA) for flexion instability. At a mean of four years, there were no re-revisions for instability. The aim of this study was to report the implant survivorship and clinical and radiological outcomes of the same cohort of of patients at a mean follow-up of ten years. The original publication included 60 revision TKAs in 60 patients which were undertaken between 2000 and 2010. The mean age of the patients at the time of revision TKA was 65 years, and 33 (55%) were female. Since that time, 21 patients died, leaving 39 patients (65%) available for analysis. The cumulative incidence of any re-revision with death as a competing risk was calculated. Knee Society Scores (KSSs) were also recorded, and updated radiographs were reviewed.Aims
Methods
Aims. The aims of this study were to investigate the ability to kneel after total knee arthroplasty (TKA) without patellar resurfacing, and its effect on patient-reported outcome measures (PROMs). Secondary aims included identifying which kneeling positions were most important to patients, and the influence of radiological parameters on the ability to kneel before and after TKA. Methods. This prospective longitudinal study involved 209 patients who underwent single radius cruciate-retaining TKA without patellar resurfacing. Preoperative EuroQol five-dimension questionnaire (EQ-5D), Oxford Knee Score (OKS), and the ability to achieve four kneeling positions were assessed including a single leg kneel, a double leg kneel, a high-flexion kneel, and a praying position. The severity of radiological osteoarthritis (OA) was graded and the pattern of OA was recorded intraoperatively. The flexion of the femoral component,
Porous metaphyseal cones can be used for fixation in revision total knee arthroplasty (rTKA) and complex TKAs. This metaphyseal fixation has led to some surgeons using shorter cemented stems instead of diaphyseal engaging cementless stems with a potential benefit of ease of obtaining proper alignment without being beholden to the diaphysis. The purpose of this study was to evaluate short term clinical and radiographic outcomes of a series of TKA cases performed using 3D-printed metaphyseal cones. A retrospective review of 86 rTKAs and nine complex primary TKAs, with an average age of 63.2 years (SD 8.2) and BMI of 34.0 kg/m2 (SD 8.7), in which metaphyseal cones were used for both femoral and tibial fixation were compared for their knee alignment based on the type of stem used. Overall, 22 knees had cementless stems on both sides, 52 had cemented stems on both sides, and 15 had mixed stems. Postoperative long-standing radiographs were evaluated for coronal and sagittal plane alignment. Adjusted logistic regression models were run to assess malalignment hip-knee-ankle (HKA) alignment beyond ± 3° and sagittal alignment of the tibial and femoral components ± 3° by stem type.Aims
Methods
The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups. This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned postioning of the components in both groups.Aims
Methods
This study aimed to evaluate the association between the sagittal alignment of the femoral component in total knee arthroplasty (TKA) and new Knee Society Score (2011KSS), under the hypothesis that outliers such as the excessive extended or flexed femoral component were related to worse clinical outcomes. A group of 156 knees (134 F:22 M) in 133 patients with a mean age 75.8 years (SD 6.4) who underwent TKA with the cruciate-substituting Bi-Surface Knee prosthesis were retrospectively enrolled. On lateral radiographs, γ angle (the angle between the distal femoral axis and the line perpendicular to the distal rear surface of the femoral component) was measured, and the patients were divided into four groups according to the γ angle. The 2011KSSs among groups were compared using the Kruskal-Wallis test. A secondary regression analysis was used to investigate the association between the 2011KSS and γ angle.Aims
Methods
The application of robotics in the operating theatre for knee arthroplasty remains controversial. As with all new technology, the introduction of new systems might be associated with a learning curve. However, guidelines on how to assess the introduction of robotics in the operating theatre are lacking. This systematic review aims to evaluate the current evidence on the learning curve of robot-assisted knee arthroplasty. An extensive literature search of PubMed, Medline, Embase, Web of Science, and Cochrane Library was conducted. Randomized controlled trials, comparative studies, and cohort studies were included. Outcomes assessed included: time required for surgery, stress levels of the surgical team, complications in regard to surgical experience level or time needed for surgery, size prediction of preoperative templating, and alignment according to the number of knee arthroplasties performed. A total of 11 studies met the inclusion criteria. Most were of medium to low quality. The operating time of robot-assisted total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) is associated with a learning curve of between six to 20 cases and six to 36 cases respectively. Surgical team stress levels show a learning curve of seven cases in TKA and six cases for UKA. Experience with the robotic systems did not influence implant positioning, preoperative planning, and postoperative complications. Robot-assisted TKA and UKA is associated with a learning curve regarding operating time and surgical team stress levels. Future evaluation of robotics in the operating theatre should include detailed measurement of the various aspects of the total operating time, including total robotic time and time needed for preoperative planning. The prior experience of the surgical team should also be evaluated and reported. Cite this article:
To compare patients undergoing total knee arthroplasty (TKA) with ≤ 80° range of movement (ROM) operated with a 2 mm increase in the flexion gap with matched non-stiff patients with at least 100° of preoperative ROM and balanced flexion and extension gaps. In a retrospective cohort study, 98 TKAs (91 patients) with a preoperative ROM of ≤ 80° were examined. Mean follow-up time was 53 months (24 to 112). All TKAs in stiff knees were performed with a 2 mm increased flexion gap. Data were compared to a matched control group of 98 TKAs (86 patients) with a mean follow-up of 43 months (24 to 89). Knees in the control group had a preoperative ROM of at least 100° and balanced flexion and extension gaps. In all stiff and non-stiff knees posterior stabilized (PS) TKAs with patellar resurfacing in combination with adequate soft tissue balancing were used.Aims
Methods
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. 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.Aims
Materials and Methods
The purpose of this multicentre observational study was to investigate the association between intraoperative component positioning and soft-tissue balancing on short-term clinical outcomes in patients undergoing robotic-arm assisted unicompartmental knee arthroplasty (UKA). Between 2013 and 2016, 363 patients (395 knees) underwent robotic-arm assisted UKAs at two centres. Pre- and postoperatively, patients were administered Knee Injury and Osteoarthritis Score (KOOS) and Forgotten Joint Score-12 (FJS-12). Results were stratified as “good” and “bad” if KOOS/FJS-12 were more than or equal to 80. Intraoperative, post-implantation robotic data relative to CT-based components placement were collected and classified. Postoperative complications were recorded.Aims
Patients and Methods
The primary aim of this study was to determine the surgical team’s
learning curve for introducing robotic-arm assisted unicompartmental
knee arthroplasty (UKA) into routine surgical practice. The secondary
objective was to compare accuracy of implant positioning in conventional
jig-based UKA versus robotic-arm assisted UKA. This prospective single-surgeon cohort study included 60 consecutive
conventional jig-based UKAs compared with 60 consecutive robotic-arm
assisted UKAs for medial compartment knee osteoarthritis. Patients
undergoing conventional UKA and robotic-arm assisted UKA were well-matched
for baseline characteristics including a mean age of 65.5 years
(Aims
Patients and Methods
Objectives.
Objectives. Preservation of
