scholarly journals Combining sensor and robotic technologies to achieve a well balanced total knee arthroplasty while avoiding any soft tissue releases

10.29007/vwhp ◽  
2020 ◽  
Author(s):  
Julien Bardou-Jacquet

Achieving a balanced total knee throughout the entire range of motion leads to improved patient reported outcomes and satisfaction. Sensor-assisted technology allows the surgeon to quantitatively assess and address imbalance through either soft tissue releases or bone recuts. However, balancing through soft tissue releases leads to unpredictable gap increments and frequent early over-releases.METHODS: During a consecutive and prospective series of 29 robotic total knee surgeries, intra-operative load sensors were used following the initial bone resections to quantitatively assess the knee’s state of balance through the range of motion with trial components in place. Load measurements were taken at 10 and 90 degrees of knee flexion. Based on previous literature, a balanced knee is defined as having a mediolateral load difference below 15 pounds (lbf) through the range of motion, with an absolute load magnitude per compartment above 5lbf and not exceeding 45lbf. The initial load numbers were recorded as well as the number and type of subsequent corrections needed to achieve quantitative balance.RESULTS Of the 29 robotics cases, only 12 (41%) were well-balanced after the initial bone cuts (mechanical alignment by measured resection). Another two cases were too loose and required an increase in the polyethylene thickness size of two millimeters to achieve a well-balanced knee without further bone resection. In 14 cases, a bone recut was required to balance the knee. More specifically, four cases required a recut of the femur, ten cases required a recut of the tibia. Eventually, one case was left unbalanced in flexion with a mediolateral load differential of 20 lbf. It should be noted explicitly that no soft tissue releases were done for any of the 29 cases. At the end, all 29 knees were considered well balanced in extension and all but six (79%) at 90° of flexion. For these six cases with balance issue at 90° of flexion, absolute load magnitude in both compartments was below 45 lbf and above 5lbf, though the mediolateral load differential was between 15lbf and 30lbf.DISCUSSION Based on a preliminary series, this work demonstrates the opportunity of combining multiple technologies to achieve a quantitatively balanced knee through the range of motion without any soft tissue release.

10.29007/grf3 ◽  
2020 ◽  
Author(s):  
Christopher Plaskos ◽  
Edgar Wakelin ◽  
Sami Shalhoub ◽  
Jeffrey Lawrence ◽  
John Keggi ◽  
...  

Soft tissue releases are often required to correct deformity and achieve balance in total knee arthroplasty (TKA). However, releasing soft tissues can be subjective, highly variable and is perceived as an ‘art’ in TKA. The objective of this study was to compare the rate of soft tissue release required to achieve a balanced knee in tibial-first gap- balancing versus conventional, measured resection TKA, and its effect on outcomes.Soft tissue releases were documented and reviewed in 1256 robotic-assisted gap- balancing and 85 robotic-assisted measured-resection TKAs. Knees were stratified by coronal deformity (varus: >2° varus; valgus: >2° valgus). Rates of releases were compared between the two groups and literature. A subset of these patients were also enrolled in a prospective study. KOOS outcomes were captured pre-operatively and at 6M post TKA.The frequency of soft tissue release was significantly lower in the robotic gap- balancing group, with 21% of knees requiring release versus 40% (p=0.001) in the robotic measured resection group and 67% (p<0.001) for conventional measured resection. Pre-operative KOOS scores were similar between groups, however 6M scores showed a significant improvement in QOL, Sports and Symptoms scores in knees not released.Robotic assisted TKA with predictive gap balancing was found to reduce the number of releases across all coronal angles compared to conventional instruments. Furthermore, performing a soft tissue release rather than bone resection to achieve balance, correlated with worse outcomes. Further research is required to understand when imbalance should be corrected with bone resection adjustment versus soft tissue release.


BMJ Open ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. e027812 ◽  
Author(s):  
Samuel J MacDessi ◽  
Aziz Bhimani ◽  
Alexander W R Burns ◽  
Darren B Chen ◽  
Anthony K L Leong ◽  
...  

IntroductionSoft tissue imbalance is considered to be a major surgical cause of dissatisfaction following total knee arthroplasty (TKA). Surgeon-determined manual assessment of ligament tension has been shown to be a poor determinant of the true knee balance state. The recent introduction of intraoperative sensors, however, allows surgeons to precisely quantify knee compartment pressures and tibiofemoral kinematics, thereby optimising coronal and sagittal plane soft tissue balance. The primary hypothesis of this study is that achieving knee balance with use of sensors in TKA will improve patient-reported outcomes when compared with manual balancing.Methods and analysisA multicentred, randomised controlled trial will compare patient-reported outcomes in 222 patients undergoing TKA using sensor-guided balancing versus manual balancing. The sensor will be used in both arms for purposes of data collection; however, surgeons will be blinded to the pressure data in patients randomised to manual balancing. The primary outcome will be the change from baseline to 1 year postoperatively in the mean of the four subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS4) that are most specific to TKA recovery: pain, symptoms, function and knee-related quality of life. Secondary outcomes will include the surgeon’s capacity to determine knee balance, radiographic and functional measures and additional patient-reported outcomes. Normality of data will be assessed, and a Student’s t-test and equivalent non-parametric tests will be used to compare differences in means among the two groups.Ethics and disseminationEthics approval was obtained from South Eastern Sydney Local Health District, Approval (HREC/18/POWH/320). Results of the trial will be presented at orthopaedic surgical meetings and submitted for publication in a peer-reviewed journal.Trial registration numberACTRN#12618000817246


10.29007/h8kn ◽  
2019 ◽  
Author(s):  
Jan Koenig ◽  
Sami Shalhoub ◽  
Eric Chen ◽  
Christopher Plaskos

Achieving proper soft tissue balance during total knee arthroplasty (TKA) can reduce post- operative instability and stiffness as well as improve patient reported outcomes. The objective of this study was to compare final intra-operative coronal balance throughout the knee range of motion in navigated robotic-assisted TKA when performed with quantifiable feedback from a robotic ligament tensioning tool versus with standard trials and navigation measurements alone.The study included a prospective cohort of 52 patients undergoing robotic-assisted TKA using a measured resection technique. The cohort was divided into two sequential groups: a non-sensor-assisted group (n=25) and a subsequent sensor-assisted group (n=27). Once bony cuts and soft tissue balancing was performed in the non-sensor cohort, the final tibiofemoral gaps were measured throughout the knee range of motion using a robotic-assisted tensioner with the surgeon blinded to the measurements. For the sensor cohort, the surgeon preformed soft-tissue releases or re-cuts in order to balance the knee using the gap measurement data from the robotic tensioner. The robotic-assisted tensioner was then used to measure the final medial and lateral gap measurements.The average mediolateral gap difference throughout the range of flexion was 1.9 ± 0.7 mm with maximum difference of 7.8 mm for the non-sensor cohort. The sensor cohort had an average mediolateral difference of 1.5 ± 0.6 mm and a maximum difference of 3.8 mm. The difference between the two groups was statistically significant from 60 to 90 degrees of flexion. 38-41% of knees were balanced to within 1 mm mediolaterally in the non-sensor group compared to 48-70% for the sensor group when measured at various flexion angles. 65-76% of knees were balanced to within 2 mm for the non-sensor group compared to 78-86% for the sensor-assisted group. The number of knees requiring subsequent soft tissue releases was similar in each group. Soft tissue balancing with the aid of a robotic tensioning tool resulted in significantly more accurate soft tissue balance than when using navigation measurements and standard trials alone in this single surgeon study.


Author(s):  
Eitan Ingall ◽  
Christian Klemt ◽  
Christopher M. Melnic ◽  
Wayne B. Cohen-Levy ◽  
Venkatsaiakhil Tirumala ◽  
...  

AbstractThis is a retrospective study. Prior studies have characterized the deleterious effects of narcotic use in patients undergoing primary total knee arthroplasty (TKA). While there is an increasing revision arthroplasty burden, data on the effect of narcotic use in the revision surgery setting remain limited. Our aim was to characterize the effect of active narcotic use at the time of revision TKA on patient-reported outcome measures (PROMs). A total of 330 consecutive patients who underwent revision TKA and completed both pre- and postoperative PROMs was identified. Due to differences in baseline characteristics, 99 opioid users were matched to 198 nonusers using the nearest-neighbor propensity score matching. Pre- and postoperative knee disability and osteoarthritis outcome score physical function (KOOS-PS), patient reported outcomes measurement information system short form (PROMIS SF) physical, PROMIS SF mental, and physical SF 10A scores were evaluated. Opioid use was identified by the medication reconciliation on the day of surgery. Propensity score–matched opioid users had significantly lower preoperative PROMs than the nonuser for KOOS-PS (45.2 vs. 53.8, p < 0.01), PROMIS SF physical (37.2 vs. 42.5, p < 0.01), PROMIS SF mental (44.2 vs. 51.3, p < 0.01), and physical SF 10A (34.1 vs. 36.8, p < 0.01). Postoperatively, opioid-users demonstrated significantly lower scores across all PROMs: KOOS-PS (59.2 vs. 67.2, p < 0.001), PROMIS SF physical (43.2 vs. 52.4, p < 0.001), PROMIS SF mental (47.5 vs. 58.9, p < 0.001), and physical SF 10A (40.5 vs. 49.4, p < 0.001). Propensity score–matched opioid-users demonstrated a significantly smaller absolute increase in scores for PROMIS SF Physical (p = 0.03) and Physical SF 10A (p < 0.01), as well as an increased hospital length of stay (p = 0.04). Patients who are actively taking opioids at the time of revision TKA report significantly lower preoperative and postoperative outcome scores. These patients are more likely to have longer hospital stays. The apparent negative effect on patient reported outcomes after revision TKA provides clinically useful data for surgeons in engaging patients in a preoperative counseling regarding narcotic use prior to revision TKA to optimize outcomes.


Author(s):  
Junren Zhang ◽  
Wofhatwa Solomon Ndou ◽  
Nathan Ng ◽  
Paul Gaston ◽  
Philip M. Simpson ◽  
...  

A correction to this paper has been published: https://doi.org/10.1007/s00167-021-06522-x


Author(s):  
Junren Zhang ◽  
Wofhatwa Solomon Ndou ◽  
Nathan Ng ◽  
Paul Gaston ◽  
Philip M. Simpson ◽  
...  

AbstractThis systematic review and meta-analysis were conducted to compare the accuracy of component positioning, alignment and balancing techniques employed, patient-reported outcomes, and complications of robotic-arm assisted total knee arthroplasty (RATKA) with manual TKA (mTKA) and the associated learning curve. Searches of PubMed, Medline and Google Scholar were performed in October 2020 using PRISMA guidelines. Search terms included “robotic”, “knee” and “arthroplasty”. The criteria for inclusion were published clinical research articles reporting the learning curve for RATKA and those comparing the component position accuracy, alignment and balancing techniques, functional outcomes, or complications with mTKA. There were 198 articles identified, following full text screening, 16 studies satisfied the inclusion criteria and reported the learning curve of rTKA (n=5), component positioning accuracy (n=6), alignment and balancing techniques (n=7), functional outcomes (n=7), or complications (n=5). Two studies reported the learning curve using CUSUM analysis to establish an inflexion point for proficiency which ranged from 7 to 11 cases and there was no learning curve for component positioning accuracy. The meta-analysis showed a significantly lower difference between planned component position and implanted component position, and the spread was narrower for RATKA compared with the mTKA group (Femur coronal: mean 1.31, 95% confidence interval (CI) 1.08–1.55, p<0.00001; Tibia coronal: mean 1.56, 95% CI 1.32–1.81, p<0.00001). Three studies reported using different alignment and balancing techniques between mTKA and RATKA, two studies used the same for both group and two studies did not state the methods used in their RATKA groups. RATKA resulted in better Knee Society Score compared to mTKA in the short-to-mid-term follow up (95%CI [− 1.23,  − 0.51], p=0.004). There was no difference in arthrofibrosis, superficial and deep infection, wound dehiscence, or overall complication rates. RATKA demonstrated improved accuracy of component positioning and patient-reported outcomes. The learning curve of RATKA for operating time was between 7 and 11 cases. Future well-powered studies on RATKAs should report on the knee alignment and balancing techniques utilised to enable better comparisons on which techniques maximise patient outcomes.Level of evidence III.


2016 ◽  
Vol 24 (8) ◽  
pp. 2525-2531 ◽  
Author(s):  
Friedrich Boettner ◽  
Lisa Renner ◽  
Danik Arana Narbarte ◽  
Claus Egidy ◽  
Martin Faschingbauer

Author(s):  
Mohammadreza Minator Sajjadi ◽  
Mohammad Ali Okhovatpour ◽  
Yaser Safaei ◽  
Behrooz Faramarzi ◽  
Reza Zandi

AbstractThe aim of this study was to assess the predictive value of the femoral intermechanical-anatomical angle (IMA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibia angle (MPTA), femorotibial or varus angle (VA), and joint line convergence angle (CA) in predicting the stage of the medial collateral ligament (MCL) during total knee arthroplasty (TKA) of varus knee. We evaluated 229 patients with osteoarthritic varus knee who underwent primary TKA, prospectively. They were categorized in three groups based on the extent of medial soft tissue release that performed during TKA Group 1, osteophytes removal and release of the deep MCL and posteromedial capsule (stage 1); Group 2, the release of the semimembranosus (stage 2); and Group 3, release of the superficial MCL (stage 3) and/or the pes anserinus (stage 4). We evaluated the preoperative standing coronal hip-knee-ankle alignment view to assessing the possible correlations between the knee angles and extent of soft tissue release. A significant difference was observed between the three groups in terms of preoperative VA, CA, and MPTA by using the Kruskal–Wallis test. The extent of medial release increased with increasing VA and CA as well as decreasing MPTA in preoperative long-leg standing radiographs. Finally, a patient with a preoperative VA larger than 19, CA larger than 6, or MPTA smaller than 81 would need a stage 3 or 4 of MCL release. The overall results showed that the VA and MPTA could be useful in predicting the extent of medial soft tissue release during TKA of varus knee.


2021 ◽  
Author(s):  
Richard Steer ◽  
Beth Tippett ◽  
R Nazim Khan ◽  
Dermot Collopy ◽  
Gavin Clark

Abstract Background: A drive to improve functional outcomes for patients undergoing total knee arthroplasty (TKA) has led to alternative alignment being used. Functional alignment (FA) uses intraoperative soft tissue tension to determine the optimal position of the prosthesis within the patients soft tissue envelope. Angular limits for bone resections are followed to prevent long term prosthesis failure. This study will use the aid of robotic assistance to plan and implement the final prosthesis position. This method has yet to be compared to the traditional mechanically aligned (MA) knee in a randomised trial. Methods: A blinded randomised control trial with 100 patients will be undertaken via Perth Hip and Knee clinic. Fifty patients will undergo a MA TKA and fifty will undergo a FA TKA. Both alignment techniques will be balanced via computer assisted navigation to assess prosthetic gaps, being achieved via the initial bony resection and further soft tissue releases as required to achieve satisfactory balance. The primary outcome will be the forgotten joint score (FJS) two years after surgery, with secondary outcomes being other patient reported outcome measures, clinical functional assessment, radiographic position and complications. Other data that will be collected will be patient demography (Sex, Age, level of activity) and medical information (grade of knee injury, any other relevant medical information). The linear statistical model will be fitted to the response (FJS), including all the other variables as covariates. Discussion: Many surgeons are utilising alternative alignment techniques with a goal of achieving better functional outcomes for their patients. Currently MA TKA remains the gold standard with good outcomes and excellent longevity. There is no published RCTs comparing FA to MA yet and only two registered studies are planned or currently in progress. This study utilizes a FA technique which differs from the two studies. This study will help determine if FA TKA has superior functional results for patients.Trial registration: This trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) http://www.anzctr.org.au: U1111-1257-2291, registered 25th Jan 2021. It is also listed on www.clinicaltrials.gov: NCT04748510


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