Robotics in total knee replacement:Current use and future implications

Robotic total knee replacement(TKR)surgery has evolved over the years with the aim of improving the overall 80% satisfaction rate associated with TKR surgery.Proponents claim higher precision in executing the pre-operative plan which results in improved alignment and possibly better clinical outcomes.Opponents suggest longer operative times with potentially higher complications and no superiority in clinical outcomes alongside increased costs.This editorial will summarize where we currently stand and the future implications of using robotics in knee replacement surgery.

The Increase in Total Knee Replacement Surgery in China: A 10-Year Real-World Study

Total knee arthroplasty (TKR) is the most common and costly surgical procedure performed, and it is considered one of the most successful clinical interventions for patients suffering from severe knee osteoarthritis (OA). The incidence of TKR, including demographics, incidence rates, lengths of hospital stay, and costs, was estimated from 2010 to 2019 by analyzing data extracted from the Joint Surgery Department in our hospital, which included a total of 6770 patients. We calculated the TKR risk ratios to compare the rate of TKR between different covariables such as gender, age group, and primary diagnoses. The annual volume of TKR increased by fivefold (5.14%), with a higher incidence observed in the 60 to 69 age group constituting approximately 36% of cases. There has also been an increase in incidence among young people (<50), which now stands at 6.2%. The rate ratio (RR) per female vs. male was found to be 3.0 and the RR of OA vs. RA was 0.09. The mean average length of stay (ALOS) in the hospital decreased from 15 to just 5 days during this period. Additionally, the adjusted mean cost per patient increased significantly from ¥ 38261 ± 3630.63 to ¥ 53115.17 ± 2831.35. The majority of TKR recipients were over 60 years old with osteoarthritis being identified as the main causative agent. It is worth noting that women are more susceptible to knee arthritis and there is a concerning shift toward younger individuals being affected by this disease. Our results indicate a rise in in-hospital costs alongside a significant decline in hospital ALOS for TKR procedures. We predict an unprecedented rise in TKR incidence in the coming years due to population aging and improving economic conditions in China.

The influence of lubricant temperature on the wear of total knee replacements

Experimental in vitro simulation can be used to predict the wear performance of total knee replacements.The in vitro simulation should aim to replicate the in vivo loading,motion and environment experienced by the joint,predicting wear and potential failure whilst minimising test artefacts.Experimental wear simulation can be sensitive to envi-ronmental conditions;the environment temperature is one variable which should be controlled and was the focus of this investigation.In this study,the wear of an all‐polymer(PEEK‐OPTIMA™polymer‐on‐UHMWPE)total knee replacement and a conventional cobalt chrome‐on‐UHMWPE implant of similar initial surface topography and geometry were investigated under elevated temperature conditions.The wear was compared to a previous study of the same implants under simulator running temperature(i.e.without heating the test environment).Under elevated temperature conditions,the wear rate of the UHMWPE tibial inserts was low against both femoral component materials(mean<2 mm3/million cycles)and significantly lower(p<0.05)than for investigations at simulator running temperature.Protein precipitation from the lubricant onto the component articulating surfaces is a possible explanation for the lower wear.This study highlights the need to understand the influence of different variables including envi-ronmental temperature to minimise the test artefacts during wear simulation which may affect the wear rates.

Short-term outcome of total knee replacement in a patient with hemophilia:A case report and review of literature

BACKGROUND Hemophilia A is a rare inherited bleeding disorder caused by mutations in the factor Ⅷ gene. This clotting factor plays an intrinsic role in the blood coagulation pathway. Patients with hemophilia may develop orthopedic manifestations such as hemarthrosis, but multiple malunion of fractures over the knee is rare and difficult to treat.CASE SUMMARY We report a patient with hemophilia A who developed severe knee osteoarthritis along with fracture malunion and nonunion. Total knee replacement was performed using a custom-made modular hinged knee prosthesis(cemented) equipped with extended distal and proximal stems. At 3 years’ follow-up, the patient exhibited excellent clinical function and remained satisfied with the surgical outcome. Surgical intervention was accompanied by rigorous coagulation factor replacement.CONCLUSION This case highlights various unique scenarios specific to individuals with hemophilia and fracture deformity.

Is the Prophylactic Administration of Povidone Iodine Intranasally Preoperatively in Elective Total Knee Replacement as Effective as MRSA Prophylactic Screening and Mupirocin Treatment?—A Retrospective Analysis

Surgical Site Infections (SSIs) remain a prevalent issue in healthcare. An average of 2% to 4% of all Total Knee Arthroplasties (TKA/TKR) result in a Prosthetic Joint Infection (PJI) (Ashraf et al. , 2018). These surgical site infections cause significant distress to the patient and require extended courses of antibiotic treatment and revision surgery of the infected joint. SSIs also reduce financial reimbursement to the surgery facility and affect the performing surgeon’s performance scores. To prevent surgical infection, healthcare facilities have implemented various screening or decolonization methods to prevent surgical infection to may cause infection. Various treatment methods exist for managing MRSA preoperatively which include Povidone Iodine (PI) application as a universal decolonization method and/or screening every patient pre-operatively for MRSA and treating MRSA-positive patients with Mupirocin ointment. Both interventions are well-established in the literature. At the author’s facility, the elective TKR populations were analyzed while each intervention was implemented. In 2019 TKR patients underwent MRSA swabbing and testing and in 2021 PI decolonization was the decolonization method of choice. The study revealed that MRSA testing and swabbing were better at reducing SSI related to MRSA than Povidone Iodine decolonization.

Population-Based and Personalized Design of Total Knee Replacement Prosthesis for Additive Manufacturing Based on Chinese Anthropometric Data

At present,most total knee replacement(TKR)prostheses on the market are designed according to the sizes of Caucasians.However,extensive studies have indicated that human anatomies differ among different ethnicities.A number of reports have indicated that Chinese TKR patients do not match with available prostheses.In this study,computed tomography(CT)images of 52 knees of Chinese men and women were used for anthropometric measurements.Index and geometric measurements were definedand used for correlation analysis.Key parameters from the measurement results were identified.Detailed geometries of knees were measured as coordinates.A deformable three-dimensional(3D)knee modelbased on anatomical coordinates correlating with the identified key parameters was generated.A pros-thesis was then designed according to the analyzed results.Surface matching analysis,bone resectionanalysis,and cadaveric trials were conducted and compared with commercial products to validate theproposed design.The femoral component designed by this study resulted in the highest accuracy(rootmean square point-to-surface(RMS PS),(1.08±0.20)mm)and lowest amount of resected bone volume(27412mm^(3))in comparison with two commercial knee prostheses.This study suggests a new approachfor population-based patient-specific femoral prosthesis design With a single,easilty acquired dimen-sion-namely,epicondyle width(ECW)-as input,a patient-specific femoral prosthesis can be designed according to the analyzed measured data and manufactured by additive manufacturing(AM)methods.Meanwhile,the reconstructed femoral condylar surface was compared with the femoral condylar surfacein the original CT scanning data The average RMS PS distance of the reconstructed femoral condylar surface among all data was(1.10±0.18)mm,which is comparable to other statistical shape modeling methods using multiple radiographs as input data.There is a need to develop an anthropometric-based knee prosthesis for the Chinese population.Based on the anthropometry of the Chinese population,our new design fits Chinese patients better and reserves more bone volume compared with current commercial prostheses,which is an essential step toward AM for personalized knee prostheses.

Effect of osteoarthritic knee flexion deformity correction by total knee arthroplasty on sagittal spinopelvic alignment in Indian population

BACKGROUND Sagittal alignment of the spine,pelvis,and lower extremities is essential for maintaining a stable and efficient posture and ambulation.Imbalance in any element can result in compensatory changes in the other elements.Knee flexion is a compensatory mechanism for spinopelvic sagittal alignment and is markedly affected in severe knee osteoarthritis(OA).The correction of knee flexion deformity(KFD)by total knee arthroplasty(TKA)can lead to complementary changes in the sagittal spinopelvic parameters(SSPs).AIM To determine the SSP changes in patients with knee OA,with or without KFD undergoing TKA.METHODS The study was conducted in 32 patients who underwent TKA.A neutral standing whole-spine lateral radiograph was performed before surgery and 3 mo after surgery in these patients.Subjects were divided into two groups(Group 1 obtained>10°corrections in KFD;group B obtained<10°correction).The pelvic tilt(PT),pelvic incidence(PI),sacral slope(SS),lumbar lordosis(LL),and sagittal vertical axis(SVA)were measured.RESULTS The median of change in PT,PI,SS,LL,and SVA was 0.20 mm,1.00 mm,2.20 mm,−0.40 mm,and 6.8 mm,respectively.The difference in the change in SSPs between the two groups was statistically non-significant.CONCLUSION SSPs,such as PI,PT,SS,LL,and SVA,do not change significantly following TKA in end-stage knee OA despite a significant correction(>10°)in KFD.

Metallosis following a clip breakage in a total knee arthroplasty implant:A case report

Background Metallosis describes the build-up of metal debris in the soft tissues after a period of metal on metal articulation. This debris can be asymptomatic or lead to catastrophic implant failure, which can present acutely, as in this case, or over a period of time. This report highlights how a metal clip used to hold the polyethylene liner to the tibial base plate broke 5 years after implantation, dislodged from its original position and went on to cause post-operative knee metallosis.case summary We present a case of a 63 year old lady admitted to our unit with an acute onset of right knee pain on top of a previous right total knee replacement. There was no associated trauma and examination revealed an erythematous, swollen and tender right knee. Blood investigations went on to display significantly raised inflammatory markers, raising the suspicion of a septic joint. This patient was taken to theatre for a knee arthrotomy and lavage of what was thought to be a septic joint when she was found to have extensive knee metallosis. On further inspection the metal clip, normally used to secure the polyethylene insert to the tibial base plate, had broken, dislodged, and had triggered this response. After the initial washout, this lady went back to theatre, once the appropriate implants were in stock, for an exchange of liner and metal clip.conclusion This case highlights this very rare complication which has never been reported in the literature and the success of this patient's management.

Assessment of a Downloadable Application with Avatar Guidance for PT-Prescribed Home Exercise after Total Knee Arthroplasty: A 30-Day Usability and Feasibility Study

Objective: To explore the usability and feasibility of a downloadable application (APP) compared to paper handouts (CONTROL) in guiding 30 days of PT-prescribed home exercise after total knee arthroplasty (TKA), and to compare functional outcomes at 30 days postoperatively between APP and CONTROL. Design: Randomized controlled usability and feasibility study. Setting: Rehabilitation laboratories at two regional medical centers. Participants: Individuals with knee osteoarthritis undergoing unilateral TKA (APP group: N = 26;mean age, 67.0 ± 8.2 y;CONTROL group: N = 31;mean age, 64.7 ± 7.7 y). Interventions: This study assessed the user experience of a downloadable app to guide 30 days of home exercises and instruction after TKA and compared exploratory outcomes to a group using paper handouts. Main Outcome Measures: The System Usability Scale (SUS) score was used to assess patient usability experience. Raw SUS scores were dichotomized (≥72% or <72%) to determine app usability against a 75% a priori criterion for mean APP group score. Feasibility for app use was similarly evaluated in the APP group only through a priori criteria applied to computing device ownership and study use, to the absence of technology-based barriers to participation, and to completion of app-based testing. Exploratory measures compared change from baseline to 30 days for functional and patient-reported outcomes between APP and CONTROL. Results: The APP group’s mean SUS score of 79.2% at 30 days exceeded the 75% threshold for good usability. The app met the predetermined a priori feasibility criteria for absence of technology-based barriers to participation (75% of participants) and completion of app-based testing (91.3% of participants). Personal computing devices were used by 71.4% of APP participants, which was below the 75% a priori feasibility criterion. No differences between the APP and CONTROL groups were observed for functional or patient-reported outcomes. Conclusions: The app-based platform met the a priori criteria for usability for 79% of APP participants. Our findings suggest that app-based, avatar-guided home exercise after TKA has acceptable usability and feasibility. The app-guided patient assessment capability also demonstrates preliminary feasibility for guiding and administering functional and self-reported outcomes assessments.

Osteotendinous Suturing for Anchorage of Medial Arthrotomy in Total Knee Arthroplasty

Aim: To develop a method for closure of the arthrotomy wound and approximation of the medial periosteum at the level of tibial tuberosity after total knee arthroplasty in severe varus deformity. Method: We describe a technique of osteotendinous suturing through the tibial tuberosity for suturing of the medially elevated periosteum. Result: This is an easily reproducible technique which results in very early mobilisation and no additional complications and has several advantages over other methods of closure. Conclusion: The osteotendinous technique can be used for medial arthrotomy closure after correction of severe varus deformities and also after partial patellar tendon avulsions in total knee arthroplasty surgeries.

New Classification and Visual Analysis of the Patella Cartilage during Total Knee Replacement

Objective: The aim of this prospective study is to evaluate how much damage the patellar cartilage presents during a total knee replacement. Methods: The damage of the articular patellar surface was analysed by visual inspection and photographs in 354 primary total knee replacements. The authors graded the degree of cartilage lesion in five groups. The cartilage status was analyzed and correlated with age, gender, side, body mass index (BMI), Kellgren-Lawrence radiographic scale and axial deviation. Results: After statistical analysis, we concluded: there was no evidence of an association between patellar arthrosis and age gender, side, weight and deformity. Conclusions: Articular cartilage was damaged in all 354 knees. Important subchondral bone exposure occurred in 274 knees (77.4%). Obese patients had more severe patellar osteoarthritis.

Shock-wave impact on the knee joint affected with osteoarthritis and after arthroplasty

Degenerative diseases significantly reduce the quality of human life.Non-invasive treatments are used in the initial stages of osteoarthritis(OA).Total knee arthroplasty is used in the late stages of osteoarthritis of the knee joint.Non-invasive methods based on mechanical action are also used for the rehabilitation of a patient after arthroplasty.This paper presents numerical models of the knee joint with degenerative OA changes and arthroplasty.Using these models,a computational study was made of the influence of the intensity of shock-wave exposure on the conditioning for the regeneration of bone and cartilage tissues.Based on the modeling results,it was found that in the knee joint with degenerative OA changes,conditions for the regeneration of cartilage and meniscus tissues were fulfilled under medium and highintensity loading.Under high-intensity loading(up to 0.9 m J/mm^(2)),the stress level was significantly below the ultimate value required for fracture.At knee arthroplasty,the conditions for bone tissue regeneration around the tibia component are fulfilled only under high-intensity loading.

The impact of individualized care after artificial knee replacement surgery for patients with valgus deformity of the knee

Objective:To evaluate the perioperative nursing of total knee arthroplasty for patients with valgus deformity of the knee.Methods:Seventy-six patients who underwent surgical treatment were enrolled in the study from March 2014 to March 2018.The patients in the control group were treated with routine nursing.The experimental group was treated not only with routine nursing but also with health education,psychological care,family social support,and other nursing intervention.Hospital for special surgery and Pittsburgh sleep quality index were used to evaluate the effect of nursing intervention on patients after operation.Results:All the index scores of the experimental group were lower than those of the control group(P<0.05),indicating that the function of the diseased limb and the patient's sleep status improved significantly after the intervention.Conclusions:Individualized nursing can improve the recovery of limb function and improve the patients'quality of life.It is very effective for nurses to implement individualized nursing measures for patients after surgery.

Ultrasound-guided continuous adductor canal block for analgesia after total knee replacement

Background There are several methods for postoperative analgesia for knee surgery.The commonly utilized method is multimodal analgesia based on continuous femoral nerve block.The aim of this study was to investigate the application of continuous adductor canal block for analgesia after total knee replacement and compare this method with continuous femoral nerve block.Methods Sixty patients scheduled for total knee replacement from June 2013 to March 2014 were randomly divided into a femoral group and an adductor group.Catheters were placed under the guidance of nerve stimulation in the femoral group and under the guidance of ultrasound in the adductor group.Operations were performed under combined spinal and epidural anesthesia.After the operations,0.2％ ropivacaine was given at a speed of 5 ml/h through catheters in all patients.Visual analogue scale （VAS） pain scores at rest and while moving were noted at 4,24,and 48 hours after the operation,and quadriceps strength was also assessed at these time-points.Secondary parameters such as doses of complementary analgesics and side effects were also recorded.Results There were no significant differences between the groups in VAS pain scores at rest or while moving,at 4,24,or 48 hours after the operation （P ＞0.05）.At these time-points,mean quadriceps strengths in the adductor group were 3.0 （2.75-3.0）,3.0 （3.0-4.0）,and 4.0 （3.0-4.0）,respectively,all of which were significantly stronger than the corresponding means in the femoral group,which were 2.0 （2.0-3.0）,2.0 （2.0-3.0）,and 3.0 （2.0-4.0）,respectively （P ＜0.05）.There were no significant differences between the groups in doses of complementary analgesics or side effects （P ＞0.05）.X-ray images of some patients showed that local anesthetic administered into the adductor canal could diffuse upward and reach the femoral triangle.Conclusions Continuous adductor canal block with 0.2％ ropivacaine could be used effectively for analgesia after total knee replacement.Compared with continuous femoral nerve block,this analgesic method has similar analgesic effects and is associated with less weakness of quadriceps muscle.

Patient-Specific Instruments Based on Knee Joint Computed Tomography and Full-Length Lower Extremity Radiography in Total Knee Replacement

Background： Restoring good alignment after total knee replacement （TKR） is still a challenge globally, and the clinical efficiency of patient-specific instruments （PSIs） remains controversial. In this study, we aimed to explore the value and significance of three-dimensional printing PSls based on knee joint computed tomography （CT） and full-length lower extremity radiography in TKR. Methods： Between June 2013 and October 2014, 31 TKRs were performed using PSIs based on knee joint CT and full-length lower extremity radiography in 31 patients （5 males and 26 females; mean age： 67.6 ± 7.9 years, body mass index [BMI]： 27.4 ±3.5 kg/m2）. Thirty-one matched patients （4 males and 27 females; mean age： 67.4± 7.2 years; mean BM 1：28.1 ± 4.6 kg/m2） who underwent TKR using conventional instruments in the same period served as the control group. The mean follow-up period was 38 months （31-47 months）. Knee Society Score （KSS）, surgical time, and postoperative drainage volume were recorded. Coronal alignment was measured on full-length radiography. Results： Twenty-three （74.2%） and 20 （64.5%） patients showed good postoperative alignment in the PSI and control groups, respectively, without significant difference between the two groups （χ2 = 0.68, P = 0.409）. The mean surgical time was 81.48± 16.40 rain and 72.90 ± 18.10 min for the PSl and control groups, respectively, without significant difference between the two groups （t = 0.41, P = 0.055）. The postoperative drainage volume was 250.9 ± 148.8 ml in the PSI group, which was significantly less than that in the control group （602. 1± 230.6 ml, t = 6.83, P 〈 0.001）. No significant difference in the KSS at the final follow-up was found between the PSI and control groups （91.06 ± 3.26 vs. 90.19±3.84, t= 0.95, P=0.870）. Conclusions： The use of PSls based on knee joint CT and standing full-length lower extremity radiography in TKR resulted in acceptable alignment compared with the use of conventional instruments, although the marginal advantage was not statistically different. Surgical time and clinical results were also similar between the two groups, However, the PSI group had less postoperative drainage.

Rotational alignment in total knee arthroplasty： nonimage-based navigation system versus conventional technique

Background Proper rotational alignment during total knee arthroplasty （TKA） is important for adequate postoperative patellofemoral and tibiofemoral kinematics,as well as for achieving balanced flexion space at 90°.The effects of computer navigation-assisted total knee replacement and conventional total knee arthroplasty on rotational alignment,mechanical axis,component position and clinical outcomes were compared.Methods Two methods were used in 82 patients and the rotation of the femoral and tibial components in the transverse plane,the combined rotation of the two components,the mismatch between them,and the mechanical axis of the lower limb were analyzed.All of these parameters were measured from postoperative radiographs and computed tomography images.Functional outcomes were compared at 6 weeks and 6 months postoperatively.Results Significant differences were found between the two techniques （P 〈0.05） in the following parameters：average rotation of the femoral component （（1.51±3.55）° vs.（-0.63±3.04）°）; combined rotation of the femoral and tibial components （2.85±4.07）° vs.（0.28±3.43）°）; and mismatch between the femoral and tibial components （（1.44±4.55）° vs.（-0.43±2.86）°）.Differences in the rotation of the tibial component were not statistically significant.The prevalence of outliers （malalignment 〉±3° intemal/external rotation） of the femoral component （31.7% vs.12.5%） and the tibial component （36.6% vs.15%） were significantly reduced when the navigation system was used （P〈0.05）.In addition,while patients in the navigation group had significantly better mechanical axis and functional outcomes at 6 weeks after surgery （P 〈0.05）,there was no significant difference between the two groups （P 〉0.05） with respect to functional outcomes at 6 months.Conclusion The navigation system exhibited higher accuracy than the conventional technique in the transverse and coronal plane,and provided better early functional outcomes.

Towards Rehabilitation at Home After Total Knee Replacement

In this paper,we present the design and implementation of an avatar-based interactive system that facilitates rehabilitation for people who have received total knee replacement surgeries.The system empowers patients to carry out exercises prescribed by a clinician at the home settings more effectively.Our system helps improve accountability for both patients and clinicians.The primary sensing modality is the Microsoft Kinect sensor,which is a depth camera that comes with a Software Development Kit(SDK).The SDK provides access to 3-dimensional skeleton joint positions to software developers,which significantly reduces the challenges in developing accurate motion tracking systems,especially for use at home.However,the Kinect sensor is not wellequipped to track foot orientation and its subtle movements.To overcome this issue,we augment the system with a commercial off-the-shelf Inertial Measurement Unit(IMU).The two sensing modalities are integrated where the Kinect serves as the primary sensing modality and the IMU is used for exercises where Kinect fails to produce accurate measurement.In this pilot study,we experiment with four rehabilitation exercises,namely,quad set,side-lying hip abduction,straight raise leg,and ankle pump.The Kinect is used to assess the first three exercises,and the IMU is used to assess the ankle pump exercise.

A New Computer Assisted Orthopaedic Surgery System:WATO

Background:The traditional manual orthopaedic technology heavily relies on a surgeon's experience,so it certainly increases the instability of the surgery.Therefore,computer assisted orthopaedic surgery(CAOS) is becoming a hot research topic for its high accuracy and stability.We developed a new CAOS system WATO,which is mainly designed for total knee replacement(TKR).Methods:WATO system provides the interactive software for a surgeon's preoperative planning.Based on its two infrared cameras,infrared markers and infrared probe,WATO system gives a simple surgical positioning procedure of femur and tibia without additional surgery for the placement of fiducial markers.According to the reference alignment axis from positioning procedure,a surgeon can move the robot of WATO system to do accurate bone resection.Safety checking is also considered in WATO system.Results:Extensive experiments were conducted on phantoms and cadaver bones to verify the accuracy and stability of WATO system.Experimental results showed that TKR using WATO system had better performance compared with traditional and navigated TKR.Conclusion:WATO system shows its superiority in TKR,and has a broad application prospect in the future.We will develop its new functions for other orthopaedic surgery such as total hip replacement(THR).Current disadvantages such as bigger skin incision have to be resolved in the future.

Criteria of Human-computer Interface Design for Computer Assisted Surgery Systems

In recent years, computer assisted surgery （CAS） systems become more and more common in clinical practices, but few specific design criteria have been proposed for human-computer interface （HCI） in GAS systems. This paper tried to give universal criteria of HCI design for CAS systems through introduction of demonstration application, which is total knee replacement （TKR） with a nonimage-based navigation system. A typical computer assisted process can be divided into four phases： the preoperative planning phase, the intraoperative registration phase, the intraoperative navigation phase and finally the postoperative assessment phase. The interface design for four steps is described respectively in the demonstration application. These criteria this paper summarized can be useful to software developers to achieve reliable and effective interfaces for new CAS systems more easily.