Improved accuracy of implant placement with an imageless handheld robotic system compared to conventional instrumentation in patients undergoing total knee arthroplasty: a prospective randomized controlled trial using CT-based assessment of radiological outcomes.

PURPOSE: Image-free handheld robotic-assisted total knee arthroplasty (RATKA) has shown to achieve desired limb alignment compared to conventional jig-based instrumented total knee arthroplasty (CTKA). The aim of this prospective randomized controlled trial (RCT) was to evaluate the accuracy of a semi-autonomous imageless handheld RATKA compared to CTKA in order to achieve the perioperative planned target alignment of the knee postoperatively. METHODS: Fifty-two patients with knee osteoarthritis were randomized in 1:1 ratio to undergo unilateral CTKA or an imageless handheld RATKA. A full-length lower limb CT-scan was obtained pre- and 6-week postoperative. The primary outcomes were radiologic measurements of achieved target hip-knee-ankle axis (HKA-axis) and implant component position including varus and external rotation and flexion of the femur component, and posterior tibial slope. The proportion of outliers in above radiographic outcomes, defined as > 3° deviation in postoperative CT measurements as compared to perioperative planned target, were also noted. Knee phenotypes were compared with use of the Coronal Plane Alignment of the Knee (CPAK) classification. RESULTS: Baseline conditions were comparable between both groups. The overall proportion and percentage of outliers (n = 38, 24.4% vs n = 9, 5.8%) was statistically significant (p < 0.001) in favor of RATKA. The achieved varus-valgus of the femoral component (varus 1.3° ± 1.7° vs valgus - 0.1° ± 1.9°, p < 0.05) with statistically significant less outliers (0% vs 88.5%, p < 0.01), the achieved HKA-axis (varus 0.4° ± 2.1° vs valgus - 1.2° ± 2.1°, p < 0.05) and the posterior tibial slope (1.4° ± 1.1° vs 3.2° ± 1.8°, p < 0.05) were more accurate with RATKA. The most common postoperative CPAK categories were type II (50% CTKA vs 61.5% RATKA), type I (3.8% CTKA vs 23.1% RATKA) and type V (26.9% CTKA vs 15.4% RATKA). CPAK classification III was only found in CTKA (19.2%). Type VI, VII, VIII, and IX were rare in both populations. CONCLUSIONS: The present trial demonstrates that an imageless handheld RATKA system can be used to accurately perioperatively plan the desired individual component implant positions with less alignment outliers whilst aiming for a constitutional alignment. LEVEL OF EVIDENCE: I.

Image-free handheld robotic-assisted technology improved the accuracy of implant positioning compared to conventional instrumentation in patients undergoing simultaneous bilateral total knee arthroplasty, without additional benefits in improvement of clinical outcomes.

PURPOSE: The purpose of this study was to compare the clinical and radiological outcomes in patients who underwent simultaneous bilateral total knee arthroplasty (SB-TKA) using either robotic-assisted TKA (RA-TKA) or conventional TKA (C-TKA). METHODS: Included were the patients who underwent SB-TKA between January 2018 and January 2020 and had a minimum follow-up of 2 years. Of 151 patients included, 117 patients were operated using an image-free handheld robotic sculpting system (RA-TKA group) and 34 patients operated using conventional instrumentation (C-TKA group). The key outcomes noted were multiple patient-reported outcomes (PROs), adverse events, and radiological outcomes. Two investigators independently measured the radiological outcomes on pre- and post-operative radiographs in coronal plane (medial proximal tibial angle [MPTA] and anatomic lateral distal femoral angle [aLDFA]) and sagittal plane (posterior tibial slope [PTS] and posterior condylar offset [PCO]). The chi-square test was used to examine categorical variables. Student's t test was used to analyze the continuous variables. RESULTS: Patients in both groups were similar in baseline characteristics (gender, body mass index, incidence of comorbidities, and length of hospital stay) except that RA-TKA group patients younger (66.7 ± 8.9 vs 70.4 ± 10.5, P = 0.037) than C-TKA group. The operative time was longer in RA-TKA group as compared to C-TKA (189.3 ± 37.1 vs 175.0 ± 28.2, P = 0.040). The final PROs at each were similar between the two groups (P > 0.05). The values of PROs at final follow-up in RA-TKA compared to C-TKA were VAS pain (0.4 ± 0.9 vs 0.4 ± 0.5), KOOS-JR (89.3 ± 5.8 vs 87.1 ± 5.3), and physical (55.9 ± 2.8 vs 55.4 ± 3.2), mental (61.1 ± 4.4 vs 60.2 ± 4.7) component of VR-12 scores, and KSS satisfaction (37.5 ± 1.1 vs 37.1 ± 2.2) (all P > 0.50 or non-significant [n.s.]). While one patient in RA-TKA required revision of femoral component for peri-prosthetic fracture, none of the patient in conventional group were revised (0.85% vs 0%, P = n.s.). The proportion of patients with outliers in RA-TKA group was lower for aLDFA (2.6% vs 22.1%, P < 0.01) and PTS (0% vs 35%, P < 0.01). CONCLUSION: This comparative study in patients undergoing SB-TKA found reduction of outliers in femoral and tibial implant positioning with RA-TKA as compared to C-TKA. There were no differences in both groups for pain, function, and satisfaction at a minimum of 2 years of follow-up. LEVEL OF EVIDENCE: III Therapeutic Study.

Estimating aspect ratio of the distal femur and proximal tibia in the Emirati population from MRI scans of the knee: a preliminary experience.

Size and shape of knee implants play an important role in the success of total knee arthroplasty. Several studies have identified anthropometric differences of the distal femur and proximal tibia between the genders and ethnicities. Ill-fitting prosthesis can cause overhang or under-fit resulting in persistence of pain, periprosthetic fracture and decreased range of motion. The purpose of this study was to estimate the aspect ratio of distal femur and proximal tibia in the Emirati population and determine whether gender differences exist within this group. Magnetic resonance imaging datasets of unilateral knees scans performed on adult Emirati patients at a tertiary care hospital were retrospectively examined. Knee parameters were obtained from 65 males and 46 females (n = 111). Females showed significantly smaller AP and ML dimensions of distal femur and lower aspect ratios compared to males (p < 0.001). Proximal tibial dimensions (AP and ML) of Emirati women are also significantly smaller compared to men. However, aspect ratio of proximal tibia did not show gender variation (p = 0.956) within the Emirati population. Emirati knees showed significant gender differences in bony dimensions and aspect ratio of the knee, and also have smaller aspect ratios when compared with most other population groups.

Achieving functional alignment in total knee arthroplasty: early experience using a second-generation imageless semi-autonomous handheld robotic sculpting system.

PURPOSE: In order to minimize errors during achieving the targeted alignment of the total knee arthroplasty (TKA) components, robotic-assisted surgery has been introduced with the aim to help surgeons to improve implant survival, clinical outcomes, and patient satisfaction. The primary goal of this paper is to highlight surgical tips and tricks on how to achieve functional alignment (FA) through intra-operative boney mapping, numeric gap, and alignment data, using the next generation of imageless robotic surgical systems. METHOD: This retrospective case-series contains planned and achieved data on the FA and joint gap data obtained from 526 patients captured and assessed with use of a semi-autonomous imageless handheld robotic sculpting systems. All patients were operated upon by two experienced TKA surgeons. RESULTS: The mean difference between planned and achieved alignment was 1.46° (≥ 7° varus group), 1.02° (< 7° varus group), 1.16° (< 7° valgus group), and 1.43° (≥ 7° valgus group). The mean observed planned and achieved extension and flexion gaps were below 1.47 mm for medial extension gaps, 1.12 mm for the lateral extension gaps, 1.4 mm for the medial flexion gaps, and 1.16 mm for the lateral flexion gaps. CONCLUSION: Analysis of these first cases highlights the capability of the next generation of imageless robotic-assisted total knee replacement using a semi-autonomous handheld robotic sculpting to maintain accuracy of the desired alignment. The system allows the surgeon to choose freely their own alignment philosophy while maintaining efficiency.

Improved joint line and posterior offset restoration in primary total knee replacement using a robotic-assisted surgical technique: An international multi-centre retrospective analysis of matched cohorts.

BACKGROUND: Accurate restoration of joint line height and posterior offset in primary Total Knee Arthroplasty (TKA) have been shown to be important factors in post-operative range of movement and function. The aim of this study was to assess the accuracy of joint line and posterior offset restoration in a group of patients that underwent robotic-assisted TKA (raTKA). A matched cohort of patients that underwent a TKA using a conventional jig-based technique was assessed for comparison. The null hypothesis was that there would be no difference between groups. METHODS: This study was a retrospective analysis of a cohort of 120 patients with end-stage knee osteoarthritis that received a TKA using the Navio Surgical System (n = 60), or Conventional manual TKA (n = 60). Procedures were performed between 1 January 2019 and 1 October 2019 at six different centres. Joint line height and posterior offset was measured pre-operatively and post-operatively on calibrated weight bearing plain radiographs of the knee. Two observers performed measurements using validated measuring tools. A BMI and age-matched cohort of patients that underwent TKA using a conventional technique in the same six centres were assessed for comparison. Mean values, standard deviations and confidence intervals are presented for change and absolute change in joint line height and posterior offset. Student's t-test was used to compare the changes between techniques. RESULTS: Patients that underwent robotic-assisted TKA had joint line height and posterior offset restored more accurately than patients undergoing TKA using a conventional technique. Average change from pre-operative measurement in joint line height using raTKA was -0.38mm [95% CI: -0.79 to 0.03] vs 0.91 [0.14 to 1.68] with the conventional technique. Average absolute change in joint line height using raTKA was 1.96mm [1.74 to 2.18] vs 4.00mm [3.68 to 4.32] with the conventional technique. Average change in posterior offset using raTKA was 0.08mm [-0.40 to 0.56] vs 1.64mm [2.47 to 0.81] with the conventional technique. Average absolute change in posterior offset with raTKA was 2.19mm [1.92 to 2.46] vs 4.24mm [3.79 to 4.69] with the conventional technique. There was a significant difference when comparing absolute change in joint line height and posterior offset between groups (p<0.01). CONCLUSION: Robotic-assisted primary TKA restores the joint line height and posterior offset more accurately than conventional jig-based techniques.

Burden, Treatment Patterns and Unmet Needs of Osteoarthritis in Dubai: a Retrospective Analysis of the Dubai Real-World Claims Database.

INTRODUCTION: Osteoarthritis (OA) is a degenerative joint disease that impacts 3.3-3.6% of population globally with significant health and societal impact. The current study assessed the disease burden, treatment patterns, and healthcare resource utilisation (HCRU) and costs in patients with OA and subgroups of hip and/or knee OA, in Dubai, United Arab Emirates (UAE). METHODOLOGY: This retrospective longitudinal case-control study collected OA-related data from January 1, 2014 to May 31, 2020 from the Dubai Real-World Claims Database (DRWD). Adults aged at least 18 years old with OA diagnosis and at least two claims and continuous enrolment during the study period were included in the study. The patients with OA were 1:1 matched with individuals without OA. The patients with OA were divided into four cohorts on the basis of an a priori algorithm: OA of the hip and/or knee (cohort 1) and (difficult-to-treat) subsets of patients with moderate-to-severe OA of the hip and/or knee (cohort 2), inadequate response or inability to tolerate at least three pain-related medications (cohort 3), and contraindications to nonsteroidal anti-inflammatory drugs (NSAIDs) (cohort 4). RESULTS: Disease burden of OA in Dubai and HCRU and treatment costs in patients with OA were evaluated from January 1, 2014 to May 31, 2021. Patients were compared with matched controls in 1:1 ratio. The overall cohort comprised 11,651 patients with a median age of 48 years and predominantly male population (61.6%). HCRU was calculated for each cohort and it was highest (United States dollar [USD] 11,354.39) in cohort 4 (patients with contraindication to NSAIDS); in cohort 3 (inability to respond to at least three pain-related medications), USD 495.30 and USD 765.14 were spent on medication and procedures, respectively. Highest cost burden was seen in cohort 4, USD 3120.49 on consumables and USD 228.18 on services. CONCLUSION: Osteoarthritis imposes a substantial healthcare and economic burden in the UAE. The study findings elucidate the unmet need among patients with difficult-to-treat OA and inform development of new therapeutics to alleviate their burden.

Comparison of Intraarticular Versus Combined Intravenous and Intraarticular Tranexamic Acid Administration in Patients Undergoing Primary Unilateral Total Knee Arthroplasty: A Randomized Controlled Trial in the Middle Eastern Patient Population.

Background: This study aimed to determine whether combined intravenous (IV) and intraarticular (IA) tranexamic acid (TXA) reduces blood loss and the requirement of blood transfusion compared to IA use alone in the middle eastern patients undergoing primary cemented unilateral total knee arthroplasty (TKA). Methods: The present study is a double-blind randomized controlled trial (RTC) comparing the efficacy of IA alone to combined IA and IV routes of TXA administration in patients undergoing primary cemented TKA using a tourniquet performed by two senior surgeons. There were 21 patients in the IA alone and 29 in the combined group. The primary outcome measure was blood transfusion requirement, hemoglobin drop, and the total estimated blood loss on day three of postoperative period. The secondary outcomes were complications including thromboembolic events, wound complications, periprosthetic infection, patient-reported outcomes (PROs) of pain visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and EuroQol 5-dimension (EQ-5D) as well as the range of motion (ROM) at one-year follow-up. Results: None of the patients in either of the comparison group required blood transfusion in the perioperative period. The drop in hemoglobin levels (2.1±1.0 vs. 2.2±1.1, P=0.84) and the total estimated blood loss (884±489 vs. 877±324, P=0.96) on the third postoperative day in the IA alone group showed no statistically significant difference compared to that in the combined group. Moreover, there were no complications noted in patients of either group. At one-year follow-up, there was no significant difference between the two comparison groups regarding the mean PROs of pain VAS, WOMAC, and EQ-5D, as well as ROM. Conclusion: According to the obtained results, this RCT in the middle eastern patient population found no additional benefit of TXA administration through combined IV and IA route over the IA alone in reducing the requirement of blood transfusion and the total blood loss. Further similar studies with larger sample sizes are needed to ascertain the ideal route of TXA administration in patients undergoing primary TKA.