Conventional Total Knee Arthroplasty Research Articles

WE7.11 Robotic-assisted versus conventional total knee arthroplasty: A Systematic Review and Meta-analysis

Abstract Aim To compare robotic-assisted total knee arthroplasty (TKA) and conventional TKA on both long-term and short-term follow-up. Methods For conducting this study, we searched four electronic databases. The outcomes were pooled as mean difference (MD) or risk ratio (RR), and 95% confidence interval. We used RevMan for performing the analysis. Results We included nine studies. The data showed a significant favoring of robotic-assisted TKA than the conventional one in mechanical alignment, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and femoral coronal outliers (MD= -1.10, 95% CI [-1.51, -0.69], p<0.00001), (MD= -1.19, 95% CI [-2.35, -0.03], p=0.04), and (RR= 0.49, 95% CI [0.30, 0.80], p=0.004) respectively. On the other hand, the conventional TKA was better in range of motion-flexion (long-term) than the robotic-assisted one (MD= -3.02, 95% CI [-3.68, -2.37], p<0.00001). However, there were no significant differences between them in knee society score-knee score, knee society score-function score, change in hospital for special surgery, and change in range of motion-extension (MD= -0.36, 95% CI [-2.43, 1.70], p=0.73), (MD= -0.34, 95% CI [-2.36, 1.68], p=0.74), (MD=0.78, 95% CI [-0.84, 2.40], p=0.34), and (MD=0.16, 95% [-1.32, 1.64], p=0.83) respectively. Conclusion Robotic-assisted TKA had better outcomes than conventional TKA regarding mechanical alignment and WOMAC. However, the conventional approach showed a better range of motion-flexion in the long term. More data is needed for the long-term outcomes.

Evaluation of Blood Loss in Conventional vs MAKOplasty Total Knee Arthroplasty

BackgroundPrimary total knee arthroplasty (TKA) has been historically associated with considerable blood loss. Allogenic transfusions, the standard of care for blood loss following TKA, carry inherent risks. With the expanding use of robotic technology in TKA, one theoretical advantage is decreased blood loss and postoperative blood transfusions requirements. The purpose of this study was to compare postoperative hemoglobin levels and the percentage of patients requiring a transfusion of allogenic packed red blood cells after conventional TKA (CTKA) vs robot-assisted TKA (RATKA). MethodsThis is a retrospective review of 486 consecutive patients undergoing either CTKA or RATKA between October 30, 2018, and June 25, 2020, by a single fellowship-trained arthroplasty surgeon. Mako SmartRobotics (Stryker, Kalamazoo, MI) was used for RATKA cases. Primary outcomes included preoperative vs postoperative hemoglobin values and postoperative blood transfusion rates between the 2 groups. ResultsThe mean hemoglobin on postoperative day 1 was 10.7 gm/dl (±1.3) in the CTKA group and 10.9 gm/dl (±1.3) in the RATKA group, P = .24. The largest decline in hemoglobin from preoperative to within 2 days postoperatively was 3.1 gm/dl (±1.1) in the CTKA group and 3.1 gm/dl (±1.1) in the RATKA group, P = .92. The percentage of patients requiring a blood transfusion was 1.1% in the CTKA group and 1.3% in the RATKA group, P = .79. ConclusionsRATKA and CTKA groups did not have significant differences in postoperative hemoglobin changes or the need for postoperative blood transfusions.

Early Clinical and Radiographic Outcomes of Robot-Assisted Versus Conventional Manual Total Knee Arthroplasty: A Randomized Controlled Study.

ObjectiveRobot‐assisted surgery has been promoted worldwide in recent years. The development of a domestic orthopaedic robot and its clinical application are therefore of great significance. This study aimed to compare the early clinical and radiographic outcomes of domestic robot‐assisted total knee arthroplasty (RA‐TKA) with conventional manual total knee arthroplasty (CM‐TKA).MethodsA total of 77 patients who underwent primary single‐sided TKA from June to December 2020 were prospectively enrolled; resulting in the inclusion of 72 patients. The patients were randomly divided into the RA‐TKA group (37 cases, with TKA being assisted by the Yuanhua Orthopaedic Robotic System) and the CM‐TKA group (35 cases, with TKA being performed using conventional tools). Knee function was evaluated by the knee range of motion (ROM), the American Knee Society Score (KSS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Postoperative radiographic results were evaluated by full‐length weight‐bearing X‐rays of the lower limb and anteroposterior and lateral X‐rays of the knee were obtained preoperatively and at 90 days postoperative. The operative duration, blood loss, postoperative knee function, radiographic outcomes, and incidence of complications were compared by Student's t‐test, Mann–Whitney U test, or chi‐square test. Serum levels of inflammatory markers before the operation and 1, 3, and 30 days after the operation were recorded and compared between the two groups.ResultsThe operation was significantly longer in the RA‐TKA group than in the CM‐TKA group (154.3 vs 115.2 min, p < 0.001). There was no significant difference in blood loss (933 vs 863 ml, p = 0.519) between the two groups. The knee ROM, KSS, and WOMAC were significantly improved in both groups 90 days after the operation compared with before the operation (p < 0.05), but there were no significant differences between the two groups (p > 0.05). The incidence of postoperative deep vein thrombosis was not statistically different between the two groups. In the radiographic findings at 90 days postoperatively we found the frequency of lateral tibial component (LTC) angle outliers was significantly lower in the RA‐TKA group (3.0% vs 29.4%, p = 0.003). The neutrophil‐to‐lymphocyte ratio (NLR) was significantly lower in the RA‐TKA group than in the CM‐TKA group on day 1 after surgery (9.9 vs 12.7, p = 0.024).ConclusionsRA‐TKA requires more time than CM‐TKA, which may be related to the learning curve and intraoperative registration. The short‐term postoperative knee functional outcomes had no differences between the two groups, and RA‐TKA improved the accuracy of tibial component alignment. Further follow‐up studies are required to investigate the long‐term outcomes.

Two-year outcome comparison of custom versus conventional total knee (TKA) implants: a retrospective cohort study

Background: Custom implants have drawn increasing interest from surgeons seeking the promise of improved coronal alignment, decreased operative time, and improved outcomes. Currently, there is no clear evidence to support those claims. This study sought to investigate whether utilization of custom implants and instrumentation would lead to a greater improvement in two-year patient-reported outcomes compared with conventional total knee arthroplasty (TKA). Methods: This is a retrospective cohort study of 287 knees that underwent either custom TKA (n=150) or conventional TKA (n=137). Primary outcome measures included changes in Oxford Knee Score (OKS) and Short-Form 12 (SF-12) mental and physical component scores at preoperative versus 2-year follow-up. A mixed effects model was utilized to make comparisons between improvements in score. The complication and revision rates were compared. Results: There was a significant improvement in all three patient-reported outcome measures from preoperative to 2-year follow-up in both the custom and conventional instrumentation group. There were no significant differences in the magnitude of improvement between the custom and conventional groups for OKS, SF-12 mental, or SF-12 physical (P=0.07, 0.19, and 0.13, respectively) at 2-year follow-up. There were no significant differences in the complication rate (P=0.69) or revision rate (P=0.60) at 2-year follow-up. Conclusions: At a minimum follow-up of 2 years, the authors found no significant differences in patient-reported outcome measures including the OKS, SF-12 mental and physical scores between custom and conventional TKAs. Additionally, there were no significant differences in complication or revision rates. Level of Evidence: Level III

Semiactive robotic-arm system versus patient-specific instrumentation in primary total knee arthroplasty: Efficacy and accuracy

To compare the difference in efficacy and accuracy during total knee arthroplasty (TKA) among robotic-arm system, patient-specific instrumentation (PSI) and conventional TKA (COTKA). Retrospective analysis of 90 advanced knee osteoarthritis (OA) patients in our hospital between June 2019 and December 2020 was conducted. Patients were divided into robotic arm-assisted (RA)TKA (group A), PSITKA (group B) and COTKA (group C), 30 cases in each group. The operation time, intraoperative bleeding, and length of hospital stay were counted. Imaging data of hip-knee-ankle angle (HKA), posterior condylar angle (PCA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and sagittal tibial component angle (sTCA) were statistically analyzed. The postoperative recovery of the patients was evaluated by Knee Society Score (KSS) and the Western Ontario Mac Master University Index Score (WOMAC). Group A had the least intraoperative bleeding. For operation time, group A was the longest compared with group B and group C (P<0.05), while group B was longer than group C (P<0.05). There was no significant difference in HKA, LDFA, and MPTA among the three groups, and the lower limb alignments were all restored to the neutral position. PCA of group A and B were both smaller than that of group C and closer to 0° (P<0.05), but the difference between group A and B was not statistically significant. The sTCA in group A was significantly better than group B, and group B was significantly better than group C (P<0.05). There were no significant differences in function scores among the three groups. Compared to the PSI and CO, RA is more minimally invasive and more accurate in radiographic results.

Total knee arthroplasty in Ranawat II valgus deformity with enlarged femoral valgus cut angle: A new technique to achieve balanced gap.

BACKGROUNDNearly 10% of patients undergoing primary total knee arthroplasty (TKA) have valgus deformity (VD) of the knee. For severe VD of the knee, a more lateral structural release is needed to achieve balance between medial and lateral space and neutral femorotibial mechanical axis (FTMA), which is challenging and technical.AIMTo introduce a new surgical technique of resection, soft tissue release, and FTMA for Ranawat type-II VD with a 5-year follow-up.METHODSA retrospective study was conducted on patients who underwent TKA from December 2011 to December 2014. Hip-knee-ankle (HKA), range of motion (ROM), Oxford knee score (OKS), and knee society score (KSS) were used to assess the joint activity of patients in the new theory TKA group (NT-TKA) and were compared with those of the conventional TKA group (C-TKA). RESULTSA total of 103 people (103 knees) were included in this study, including 42 patients with an average follow-up period of 83 mo in the C-TKA group and 61 patients with an average follow-up period of 76 mo in the NT-TKA group. Six patients had constrained prosthesis, one had common peroneal nerve injury, and two had joint instability in the C-TKA group, but none of these occurred in the NT-TKA group. There were significant statistical differences in constrained prosthesis usage and complications between the groups (P = 0.002 and P = 0.034, respectively). The KSS at 1 mo post-operation for the C-TKA and NT-TKA groups were 11.2 ± 3.8 and 13.3 ± 2.9, respectively, with a significant difference (P = 0.007). However, the data of HKA, ROM, OKS KSS, and prosthesis survival rate were insignificant (P > 0.05) in both the preoperative and follow-up periods.CONCLUSIONAdopting 5°-7° valgus cut angle for VD and sacrificing 2° neutral FTMA for severe VD which cannot be completely corrected during TKA can reduce the need for soft tissue release, maintain early joint stability, reduce the use of constrained prostheses, and minimize postoperative complications.

An Early-stage Comparison of Functional Outcomes Following Robotic-assisted Versus Conventional Total Knee Arthroplasty: A Systematic Review and Meta-analysis

Introduction: Conventional total knee arthroplasty (cTKA) is used to relieve pain and restore knee function and stability. Robotic-assisted TKA (rTKA) was introduced to improve the placement of surgical implants, decrease postoperative complications, and improve implant longevity. To date, studies examining functional outcomes and patient-reported pain between rTKA and cTKA in the short-term postoperative period are limited, and a meta-analysis of such early-stage outcomes has yet to be accomplished. Our study aims to evaluate the differences in function, alignment, and pain between rTKA and cTKA within 6 months postoperatively through meta-analysis. Materials and Methods: A literature search of the PubMed and Cochrane electronic databases was performed in December 2021 with Medical Subject Headings and search terms limited to “knee replacement,” “knee arthroplasty,” and “robotic knee surgery.” Subsequent analysis was conducted on all retrieved studies written in English. Results: Thirteen clinical studies were considered for systematic review, of which nine were included in meta-analysis. 1,336 cases of TKA were analyzed: RTKA (n = 618) and cTKA (n = 718). There were no significant differences between rTKA and cTKA in range of motion (mean difference,-0.08°; P = 0.55), functional score of the Knee Society Score (mean difference, 0.04; P = 0.78), oxford knee score (mean difference, −0.04; P = 0.81), and Functional score of the western ontario and mcmaster universities osteoarthritis index (WOMAC-F) (mean difference, −0.42; P = 0.41). There were no significant pain differences in Short Form Health Survey Bodily Pain (mean difference, −0.08; P = 0.64) and pain score of the WOMAC (WOMAC-P) (mean difference, −0.25; P = 0.47). However, rTKA subjects achieved more accurate mechanical axis alignment than cTKA subjects (mean difference, −0.50°; P &lt; 0.01). Conclusion: Although limb alignment correction is more accurate in rTKA than cTKA, functional and pain metrics are comparable between the two procedures within 6 months’ follow-up, suggesting no added clinical benefits for rTKA versus cTKA.

A Newly Designed “SkyWalker” Robot Applied in Total Knee Arthroplasty: A Retrospective Cohort Study for Femoral Rotational Alignment Restoration

ObjectiveThis study explored whether robotic arm‐assisted total knee arthroplasty (RATKA) has the advantage of restoring femoral rotational alignment compared to conventional total knee arthroplasty (COTKA).MethodsSixty patients (45 women and 15 men) attending our department from May 2019 to December 2020 were selected and divided into two groups, with 30 patients in each group, according to whether they underwent COTKA or RATKA. Femoral rotational alignment results, such as, posterior condylar angle (PCA), patella transverse axis‐femoral transepicondylar axis angle (PFA), radiological findings, such as, hip‐knee‐ankle angle (HKA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA), and operative data (operation time, intraoperative blood loss, tourniquet time, and length of stay (LOS), and clinical outcomes, such as maximum knee flexion angle (MKFA), Knee Society Score (KSS), and Western Ontario Mac Master University Index Score (WOMAC) were compared within and between the two groups.ResultsPCA and PFA in the RATKA group were (0.6 ± 0.3)° and (0.9 ± 0.3)°, respectively, which were smaller than (1.5 ± 2.0)° and (3.1 ± 1.1)° in the COTKA group (P < 0.05), and were closer to 0°; the differences in HKA, LDFA, and MPTA were not statistically significant. With the exception of the LDFA, the HKA, MPTA, PCA, and PFA improved in both groups after surgery (P < 0.05). The blood loss and the LOS of RATKA group were 192.3 ± 23.1 mL and 8.2 ± 1.4 days, which were less than 203.7 ± 29.8 mL and 9.3 ± 1.1 days of the COTKA group, but the operation time showed no statistically significant difference, and the tourniquet time was longer (P < 0.05). The MKFA in the RATKA group was (123.0 ± 3.7)°, which was greater than (116.3 ± 4.6)° in the COTKA group (P < 0.05). In terms of scores, the postoperative results were better than the preoperative results in both groups (P < 0.05). However, there was no statistically significant difference between the groups.ConclusionThe accuracy of femoral rotational alignment reconstructed achieved by RATKA is significantly better than that of COTKA and is more conducive to the recovery of knee flexion function after surgery; although RATKA reduces intraoperative blood loss and postoperative LOS, the short‐term clinical efficacy comparison has not yet demonstrated the advantages of robotic technology, and a more optimized design is needed to improve the efficiency of RATKA surgery.

Learning curve for robotic assisted total knee arthroplasty: our experience with imageless hand-held Navio system.

The main purpose of this study was to determine the learning curve of Robotic assisted Total Knee Arthroplasty surgery through assessment of operative time and comparison with that of conventional jig based Total Knee Arthroplasty. The study included our first 75 Robotic assisted Total Knee Arthroplasty and 25 randomly selected conventional jig-based Total knee arthroplasty from June 2017 to December 2017. The 75 cases were divided into 3 groups of 25 consecutive cases. The mean of operative time for each phase and total time was compared between the 3 groups and with the mean of total time for conventional jig based group. In our experience, Robotic assisted Total Knee arthroplasty was associated with a learning curve of approximately 25 cases. The mean for Registration phase of Group A (1st set of 25 cases) was 6.12min (SD 1.8min), group B (2nd set of 25 cases) was 4.46min (SD 0.79min) and group C (3rd set of 25 cases) was 4.17min (SD 0.59min). The mean for Planning phase of group A was 5.08min (SD 1.01min), group B was 4.04min (SD 0.37min) and group C was 4.01min (SD 0.35min). The mean for Cutting Phase of group A was 28.22min (SD 6.24min), group B was 22.49min (SD 0.79min) and group C was 22.36min (SD 0.88min). The mean for total time of group A was 39.42min (SD 8.02), group B was 31min (SD 1.22min), group C was 30.53min (SD 1.14min) and conventional group was 30.54min (SD 1.14min). On comparing the Registration phase (Group A vs B, p < 0.001; Group B vs C, p 0.14; Group A vs C, p < 0.001), Planning phase (Group A vs B, p < 0.001; Group B vs C, p 0.75; Group A vs C, p < 0.001), Cutting phase (Group A vs B, p < 0.001; Group B vs C, p 0.58; Group A vs C, p < 0.001) and Total time (Group A vs B, p < 0.001; Group B vs C, p 0.74; Group A vs C, p < 0.001; Group A vs Conventional, p < 0.001; Group B vs Conventional, p 0.17, Group C vs Conventional, p 0.99), the results showed that the inflection point for learning curve in our hands was 25 cases. The learning curve and increased operation theatre time are likely to be major barrier in widespread acceptance of robotic technology amongst arthroplasty surgeons. We, in our experience can say that the learning curve was approximately 25 cases. The results of this study will help the arthroplasty surgeons in accepting this technology and achieve better outcomes.

Revisiting Short-term Outcomes of Conventional and Computer-Assisted Total Knee Arthroplasty: A Population-based Study.

Background:Population-based studies showing the advantage of computer-assisted total knee arthroplasty (CATKA) over conventional total knee arthroplasty (TKA) are outdated. More recent institution-based studies with relatively small sample sizes may hinder wider adoption. This cohort-based study aimed to compare postoperative CATKA and TKA in-hospital complications and 90-day all-cause readmissions using 2017-2018 data.Methods:Patients who underwent a primary unilateral CATKA or TKA were identified in the New York Statewide Planning and Research Cooperative System database. In-hospital complications were defined based on the 2020 Centers for Medicare & Medicaid Services total hip arthroplasty and TKA complications measure. Ninety-day readmissions were identified using unique patient identifiers. Logistic regression with a generalized estimating equation was used to assess associations of computer assistance with in-hospital complications and 90-day all-cause readmissions.Results:A total of 80,468 TKAs were identified during the study period, of which 7,395 (9.2%) were CATKAs. Significantly fewer complications occurred among patients who had CATKAs compared with conventional TKAs (0.4% of total CATKAs vs 2.6% of total conventional TKAs, P < 0.001); patients who had CATKAs had fewer 90-day all-cause readmissions compared with those who underwent TKAs (363 vs 4,169 revisits, P < 0.01). Computer assistance was associated with significantly lower odds of in-hospital complications (odds ratio, 0.15, 95% confidence interval, 0.09 to 0.24; P < 0.05) but not 90-day all-cause readmissions.Conclusion:Patients undergoing CATKAs had markedly lower odds of in-hospital complications, compared with patients having TKAs, which has implications for both patient outcomes and hospital reimbursement. These more recent cohort-based findings encourage wider CATKA adoption.

Imageless Computer Navigation Reduces 5-Year All-Cause Revision Rates After Primary Total Knee Arthroplasty.

The use of surgical navigation has been shown to reduce revision rates after total knee arthroplasty (TKA) in patients <65 years of age. It is unknown if this benefit extends to older patients. We hypothesized that the use of surgical navigation would reduce rates of all-cause revision in patients of all ages. In this cohort study, we queried the Truven MarketScan all-payer database to identify patients who underwent TKA from 2007 to 2015. Current Procedural Terminology codes were used to create 2 groups based on whether intraoperative navigation was used. Demographics, comorbidities, complications, and revision rates were determined. International Classification of Diseases codes were used to determine reasons for revision. The conventional TKA cohort included 312,173 patients. The navigation cohort included 20,881 patients. There were not any clinically significant differences in demographics between the cohorts. All-cause revision rates were lower in the navigation cohort at 1 year (0.4% vs 0.5%, P= .04), 2 years (0.7% vs 0.9%, P= .003), and 5 years (0.9% vs 1.3%, P < .001) of follow-up. Revisions for mechanical loosening were more common in the conventional cohort (30.8% vs 21.9%, P= .009). Rates of revision for other causes, including infection, did not differ between groups, with the numbers available. The use of surgical navigation yielded a 30.7% reduction in the all-cause revision rate at 5-year follow-up compared to conventional TKA. This benefit increased as follow-up duration increased. Increased usage of this inexpensive technology, from the current 6.3% in this US cohort, may reduce healthcare costs. III.

Stress and Strain During Total Joint Arthroplasty Are Not Impacted by Hand Dominance or Operative Laterality in Orthopedic Surgeons.

Orthopedic surgeons experience significant musculoskeletal pain and work-related injuries while performing total joint arthroplasty (TJA). We sought to investigate the impact of operative extremity and surgeon limb dominance on surgeon physiologic stress and energy expenditure during TJA. This was a prospective cohort study conducted at a tertiary academic practice. Cardiorespiratory data was recorded continuously in 3 high-volume arthroplasty surgeons using a smart garment that measured heart rate (HR), HR variability, respiratory rate, minute ventilation, and energy expenditure (calories) during conventional total knee (TKA) and total hip arthroplasty (THA). Surgeon 1 and 2 (right-handed) performed 21 right TKAs, 10 left TKAs, 13 right THAs, and 10 left THAs. Surgeon 3 (left-handed) performed 6 right TKAs, 9 left TKAs, 16 right THAs, and 10 left THAs. While performing TKA or THA, limb laterality had no significant impact on operative time and no significant differences existed in HR, HR variability, respiratory rate, minute ventilation, or energy expenditure for any right-handed or left-handed surgeons, regardless of the operative limb laterality. While performing TKA, consistently standing on the side of hand dominance was associated with decreased strain and stress, compared to always standing on the operative side. This study suggests that surgeon hand dominance and operative limb laterality do not impact energy expenditure or physiologic strain during TJA. However, consistently standing on the side of hand dominance in TKA may lead to decreased physiologic strain and stress during surgery. Further study utilizing wearable technology during TJA may provide orthopedic surgeons with information about modifiable factors that contribute to differences in physiological parameters during surgery.

Comparison of Survival Rate and Outcomes Between Conventional and Navigation-Assisted Primary Total Knee Arthroplasty in Severe Varus Knees: A Minimum 10-Year Follow-Up

BackgroundThis study aimed to compare the long-term clinical and radiographic outcomes and survival rates between navigation-assisted (NAV) total knee arthroplasty (TKA) and conventional (CON) TKA in patients with preoperative severe varus deformity. MethodsFrom January 2005 to December 2011, 152 TKAs and 62 TKAs with preoperative hip-knee-ankle (HKA) angles more than 15° were enrolled in the CON-TKA and NAV-TKA group with 135.7 months follow-up. Clinical outcomes (Western Ontario and McMaster University Osteoarthritis Index and Knee Society Scores), radiographic outcomes (HKA, α, β, γ, and δ angles), and survivorship were compared between the groups. ResultsThe mean value of radiographic outcomes was not statistically different; however, outliers of the HKA angle were significantly higher in the CON-TKA group (18.4% versus 8.1%, P = .04). However, long-term clinical outcomes were similar between both groups. The cumulative survival rate was 96.1% in the CON-TKA group and 96.8% in the NAV-TKA group, with no difference between the groups (P = .962). ConclusionNAV-TKA showed fewer outliers in the HKA angle for severe preoperative varus deformity compared with CON-TKA. The long-term clinical outcomes and survival rates were similar between the 2 techniques. A survival rate of more than 96% was observed in both groups. Study DesignLevel III, retrospective comparative study.

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

BackgroundThe 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).MethodsWe 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.ResultsThe 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).ConclusionsIn 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.

Extramedullary Tibial Guide Alignment Is Not Affected by Excess Lower Limb Fat Distribution in Total Knee Arthroplasty.

BackgroundThe goal of this study is to investigate whether excess lower limb fat distribution affects tibial guide alignment in conventional total knee arthroplasty (TKA) with extramedullary guides. A thicker soft tissue envelope may affect the accuracy of extramedullary cutting guide placement and subsequent instrumentation. Previous studies have used body mass index (BMI) to stratify patients, a poor proxy of lower limb fat distribution, which may explain conflicting results reported on this topic to date. This study overcomes this issue by using a novel, radiographic anthropometric index to assess lower limb fat distribution.MethodologyThis is a single-surgeon, single-implant, single-centre retrospective series of 102 consecutive primary TKAs. The suprapatellar fat index (SPFI) and BMI were recorded for all patients, and postoperative tibial component alignment measurements were calculated. Secondary outcome measures included femoral component alignment, femorotibial alignment, length of hospital stay, tourniquet time, blood loss, and complications/reoperations.ResultsIn this study, 102 patients (average age of 69) had an average BMI of 30.8 kg/m2 (19.2-45.5 kg/m2) and an average SPFI of 0.26 (0.09-0.57). Multiple regression analysis demonstrated that increasing leg fat distribution did not affect tibial component alignment in the coronal or sagittal plane.ConclusionsExcess lower limb fat distribution, simply measured using the SPFI, does nothave a significant effect on tibial component positioning when extramedullary guides are used in conventional TKA.

No Difference in Quality-Of-Life Outcomes in the First 7 Years Following Primary Total Knee Arthroplasty Performed Using Computer Navigation Versus Conventional Referencing: A Propensity Score-Matched Analysis

BackgroundComputer navigation techniques can potentially improve both the accuracy and precision of prosthesis implantation in total knee arthroplasty (TKA) but its impact on quality-of-life outcomes following surgery remains unestablished. MethodsAn institutional arthroplasty registry was queried to identify patients with TKA performed between January 1, 2007 and December 31, 2019. Propensity score matching based on demographical, medical, and surgical variables was used to match computer-navigated to conventionally referenced cases. The primary outcomes were Veterans RAND 12 Item Health Survey scores (VR-12 PCS and MCS), Short Form 6 Dimension utility values (SF-6D), and quality-adjusted life years (QALYs) in the first 7 years following surgery. ResultsA total of 629 computer-navigated TKAs were successfully matched to 1,351 conventional TKAs. The VR-12 PCS improved by a mean of 12.75 and 11.94 points in computer-navigated and conventional cases at 12-month follow-up (P = .25) and the VR-12 MCS by 6.91 and 5.93 points (P = .25), respectively. The mean VR-12 PCS improvement at 7-year follow-up (34.4% of the original matched cohort) for navigated and conventional cases was 13.00 and 12.92 points (P = .96) and for the VR-12 MCS was 4.83 and 6.30 points (P = .47), respectively. The mean improvement in the SF-6D utility score was 0.164 and 0.149 points at 12 months (P = .11) and at 7 years was 0.115 and 0.123 points (P = .69), respectively. Computer-navigated cases accumulated 0.809 QALYs in the first 7 years, compared to 0.875 QALYs in conventionally referenced cases (P = .65). There were no differences in these outcomes among a subgroup analysis of obese patients (body mass index ≥ 30 kg/m2). ConclusionThe use of computer navigation did not provide an incremental benefit to quality-of-life outcomes at a mean of 2.9 years following primary TKA performed for osteoarthritis when compared to conventional referencing techniques.

Decreased patient comorbidities and post-operative complications in technology-assisted compared to conventional total knee arthroplasty.

The use of computer-assisted and robotic surgery was developed to improve component position and outcomes of total knee arthroplasty (TKA). The goal of this study is to identify differences in patient demographics, comorbidities, and complications between technology-assisted and conventional TKA. A Nationwide Inpatient Sample database was used to identify patients who underwent technology-assisted and conventional TKA from 2016 to 2018. Analysed variables include demographics, length of stay (LOS), payer-status, geographic region, comorbidities, complications, and mortality. Univariate and multivariate analyses were performed to identify differences between both groups. The analysis includes 2,208,434 TKA patients, of which 2,054,879 (93.05%) were conventional and 153,555 (6.95%) were technology assisted. Patients undergoing technology-assisted TKA were more likely to be older than 65years, had higher median income quartile, and had surgery in urban teaching hospitals. Patients were less likely to undergo technology-assisted TKA if they were female gender, had Medicare payer status, were black race, were obese, were living in rural location, or had higher Charlson comorbidity score and baseline comorbidities. Technology-assisted TKA patients had shorter LOS, and fewer pulmonary and infection complications. Patients undergoing technology-assisted TKA are being carefully selected with less baseline comorbidities, improved health, and living in urban areas. Subsequently, those carefully selected patients are discharged home, have a shorted hospital LOS, and have fewer complications compared to conventional TKA. Rural patients, black race and female gender are less likely to undergo technology-assisted TKA, further emphasizing the healthcare disparity for that segment of the population. Therapeutic level III.

Robotics versus personalized 3D preoperative planning in total knee arthroplasty: a propensity score-matched analysis

PurposeLower limb alignment is crucial in total knee arthroplasty (TKA). Previous studies have shown that robotics and personalized three-dimensional (3D) preoperative planning could improve postoperative alignment accuracy compared with conventional TKA, but comparison between the above two techniques has never been reported. The authors hypothesized that robotics may be superior to personalized 3D preoperative planning in terms of postoperative alignment in primary TKA, with similar patient-reported outcome measures (PROMs) but higher cost and longer operative time.MethodsA consecutive series of patients who received TKA in our center from September 2020 to January 2021 were enrolled retrospectively. After 1:2 matching, 52 and 104 patients were included and divided into study group for robotics and control group for personalized 3D preoperative planning, respectively. Multiple postoperative alignment angles were measured, and clinical features such as operation and tourniquet time, length of hospital stay and hemoglobin (Hb) were recorded. Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used to evaluate clinical results.ResultsCompared with control group, robotics group had significantly lower frontal femoral component angle (FFC) and frontal tibial component angle (FTC) absolute deviation (P < 0.05). It also had less outliers in hip–knee–ankle angle (HKA), FTC, lateral femoral component angle (LFC) and lateral tibial component angle (LTC) (P < 0.05). Hb loss of robotics group was significantly lower than control group (P < 0.001), while the operation and tourniquet time were longer (P < 0.001). There was no significant difference in KSS and WOMAC scores between two groups.ConclusionCompared with control group, patients in robotics group had significantly less malalignment, malposition, Hb loss, but similar PROMs. The operations in robotics group spent longer operation time and cost more compared with control group.Trial registration: The Chinese Clinical Trial Registry, ChiCTR2000036235. Registered 22 August 2020, http://www.chictr.org.cn/showproj.aspx?proj=59300.Level of evidenceIII.

Are there functional biomechanical differences in robotic arm-assisted bi-unicompartmental knee arthroplasty compared with conventional total knee arthroplasty? A prospective, randomized controlled trial.

The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery. A total of 76 patients (34 bi-UKA and 42 TKA patients) were analyzed in a prospective, single-centre, randomized controlled trial. Flat ground shod gait analysis was performed preoperatively and one year postoperatively. Knee flexion moment was calculated from motion capture markers and force plates. The same setup determined proprioception outcomes during a joint position sense test and one-leg standing. Surgery allocation, surgeon, and secondary outcomes were analyzed for prediction of the primary outcome from a binary regression model. Both interventions were shown to be effective treatment options, with no significant differences shown between interventions for the primary outcome of this study (18/35 (51.4%) biphasic TKA patients vs 20/31 (64.5%) biphasic bi-UKA patients; p = 0.558). All outcomes were compared to an age-matched, healthy cohort that outperformed both groups, indicating residual deficits exists following surgery. Logistic regression analysis of primary outcome with secondary outcomes indicated that the most significant predictor of postoperative biphasic knee moments was preoperative knee moment profile and trochlear degradation (Outerbridge) (R2 = 0.381; p = 0.002, p = 0.046). A separate regression of alignment against primary outcome indicated significant bi-UKA femoral and tibial axial alignment (R2 = 0.352; p = 0.029), and TKA femoral sagittal alignment (R2 = 0.252; p = 0.016). The bi-UKA group showed a significant increased ability in the proprioceptive joint position test, but no difference was found in more dynamic testing of proprioception. Robotic arm-assisted bi-UKA demonstrated equivalence to TKA in achieving a biphasic gait pattern after surgery for osteoarthritis of the knee. Both treatments are successful at improving gait, but both leave the patients with a functional limitation that is not present in healthy age-matched controls. Cite this article: Bone Joint J2022;103-B(4):433-443.

Surgeons Experience Greater Cardiorespiratory Strain and Stress During Total Hip Arthroplasty Than Total Knee Arthroplasty.

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are physically demanding, with a high prevalence of work-related injuries among arthroplasty surgeons. It is unknown whether there are differences in cardiorespiratory output for surgeons while performing THA and TKA. The objective of this study is to characterize whether differences in surgeon physiological response exist while performing primary THA vs TKA. This is a prospective cohort study including 3 high-volume, fellowship-trained arthroplasty surgeons who wore a smart garment that recorded cardiorespiratory data on operative days during which they were performing primary conventional TKA and THA. Variables collected included patient body mass index (BMI), operative time (minutes), heart rate, heart rate variability, respiratory rate, minute ventilation, and energy expenditure (calories). Seventy-six consecutive cases (49 THAs and 27 TKAs) were studied. Patient BMI was similar between the 2 cohorts (P > .05), while operative time was significantly longer in TKAs (60.4±12.0 vs 53.6±11.8; P= .029). During THA, surgeons had a significantly higher heart rate (95.7±9.1 vs 90.2±8.9; P= .012), energy expenditure per minute (4.6±1.23 vs 3.8±1.2; P= .007), and minute ventilation (19.0±3.0 vs 15.5±3.3; P < .001) compared to TKA. Surgeons experience significantly higher physiological strain and stress while performing THA. While scheduling THAs and TKAs, surgeons should consider the higher physical demand associated with THAs and ensure adequate personal preparation and sequence of cases.