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.

Safety and outcomes of hip and knee replacement surgery in liver transplant recipients

BACKGROUND Liver transplant(LT)is becoming increasingly common with improved life expectancy.Joint replacement is usually a safe procedure;however,its safety in LT recipients remains understudied.AIM To evaluate the mortality,outcome,and 90-d readmission rate in LT patients undergoing hip and knee replacement surgery.METHODS Patients with history of LT who underwent hip and knee replacement surgery between 2016 and 2019 were identified using the National Readmission Database.RESULTS A total of 5046119 hip and knee replacement surgeries were identified.3219 patients had prior LT.Mean age of patients with no history of LT was 67.51[95%confidence interval(CI):67.44-67.58],while it was 64.05(95%CI:63.55-64.54)in patients with LT.Patients with history of LT were more likely to have prolonged length of hospital stay(17.1%vs 8.4%,P<0.001).The mortality rate for patients with no history of LT was 0.22%,while it was 0.24%for patients with LT(P=0.792).Patients with history of LT were more likely to have re-admissions within 90 d of initial hospitalization:11.4%as compared to 6.2%in patients without history of LT(P<0.001).The mortality rate between both groups during readmission was not statistically different(1.9%vs 2%,P=0.871)respectively.CONCLUSION Hip and knee replacements in patients with history of LT are not associated with increased mortality;increased readmissions were more frequent in this cohort of patients.Chronic kidney disease and congestive heart failure appear to predict higher risk of readmission.

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.

Cementless Semi-Constrained Rotating Platform Total Knee Replacement: A Concise Follow-Up of a Previous Report at a Minimum of Twenty Years

Background: A previous report evaluated the initial 310 cementless, Buechel-Pappas (B-P), Semi-Constrained Rotating Platform total knee replacements in 257 patients followed for an average of 7.6 years, range 2 - 18 years. Diagnoses were osteoarthritis in 233 patients, post traumatic arthritis in 4 patients and rheumatoid arthritis in 22 patients. Knee Scores, using a strict knee scoring scale were 86.4% excellent, 12.3% good, 0.3% fair and 1.0% poor results. Survivorship, using an end point of revision for any mechanical reason (including component loosening, bearing wear and bearing dislocation) was 99.4%. Survivorship for a poor knee score (including persistent pain, loosening, instability and infection was 97.6%. The purpose of the present study is to report the updated results of this same patient cohort at a minimum follow-up of twenty years. Methods: The average age of patients at the time of surgery was 67 years, range 34 to 91 years. A total of 20 patients (22 knees) were still living, with a follow-up of 20 - 30 years (mean 23.47 years). The same strict knee scoring scale and survivorship analysis were used to evaluate patient outcomes at the 20 to 30 years interval. Results: Survivorship, in the current study, using the same end points as in the previous study, was 96.5% at the 20 and 30-year intervals. Late mechanical failure and osteolysis were not identified. Conclusion: This cementless, semi-constrained rotating platform total knee replacement has stood the test of time for more than 20 years and can be considered acceptable for long-term use, in properly selected patients.

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.

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.

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.

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.

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.

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.

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.

Graph Theory and Matrix Approach(GTMA)Model for the Selec­tion of the Femoral-Component of Total Knee Joint Replacement

Total Knee Replacement(TKR)is the increasing trend now a day,in revision surgery which is associated with aseptic loosening,which is a challenging research for the TKR component.The selection of optimal material loosening can be controlled at some limits.This paper is going to consider the best material selected among a number of alternative materials for the femoral component(FC)by using Graph Theory.Here GTMA process used for optimization of material and a systematic technique introduced through sensitivity analysis to find out the more reliable result.Obtained ranking suggests the use of optimized material over the other existing material.By following GTMA Co_Cr-alloys(wrought-Co-Ni-Cr-Mo)and Co_Cr-alloys(cast-able-Co-Cr-Mo)are on the 1st and 2nd position respectively.

Effect of enhanced recovery after surgery with multidisciplinary collaboration on nursing outcomes after total knee arthroplasty

BACKGROUND There is a lack of studies on the effects of enhanced recovery after surgery(ERAS)with multidisciplinary collaboration on the nursing outcomes of total knee arthroplasty(TKA).AIM To explore the effect of ERAS with multidisciplinary collaboration on nursing outcomes after TKA.METHODS We retrospectively analyzed the clinical data of 80 patients who underwent TKA at a tertiary hospital between January 2021 and December 2022.The patients were divided into two groups according to the nursing mode:the ERAS group(n=40)received ERAS with multidisciplinary collaboration,and the conventional group(n=40)received routine nursing.The following indicators were compared between the two groups:length of hospital stay,hospitalization cost,intraoperative blood loss,hemoglobin level 24 h after surgery,visual analog scale(VAS)score for pain,range of motion(ROM)of the knee joint,Hospital for Special Surgery(HSS)knee score,and postoperative complications.RESULTS The ERAS group had a significantly shorter length of hospital stay,lower hospitalization cost,less intraoperative blood loss,higher hemoglobin level 24 h after surgery,lower VAS score for pain,higher knee joint ROM,and higher HSS knee score than the conventional group(all P<0.05).There was no significant difference in the incidence of postoperative complications between the two groups(P>0.05).CONCLUSION Multidisciplinary collaboration with ERAS can reduce blood loss,shorten hospital stay,and improve knee function in patients undergoing TKA.

Developing an enhanced recovery after surgery program for oncology patients who undergo hip or knee reconstruction surgery

Enhanced recovery after surgery(ERAS)protocols are applied in orthopedic surgery and are intended to reduce perioperative stress by implementing combined evidence-based practices with the cooperation of various health professionals as an interdisciplinary team.ERAS pathways include pre-operative patient counselling,regional anesthesia and analgesia techniques,post-operative pain management,early mobilization and early feeding.Studies have shown improvement in the recovery of patients who followed an ERAS program after hip or knee arthroplasty,compared with those who followed a traditional care approach.ERAS protocols reduce post-operative stress,contribute to rapid recovery,shorten length of stay(LOS)without increasing the complications or readmissions,improve patient satisfaction and decrease the hospital costs.We suggest that the ERAS pathway could reduce the LOS in hospital for patients undergoing total hip replacement or total knee replacement.These programs require good organization and handling by the multidisciplinary team.ERAS programs increase patient's satisfaction due to their active participation which they experience as personalized treatment.The aim of the study was to develop an ERAS protocol for oncology patients who undergo bone reconstruction surgeries using massive endoprosthesis,with a view to improving the surgical outcomes.

Association of vitamin D and knee osteoarthritis in younger individuals

BACKGROUND The incidence of primary osteoarthritis knee is gradually increasing among young individuals.The increasing prevalence of obesity,sedentary lifestyle,sporting activity,and vitamin D deficiency(VDD)has been hypothesized for this shifting disease trend.This study was designed to look for the association of serum vitamin D among these young arthritic patients.AIM To look for the association of serum vitamin D in younger knee osteoarthritis(KOA)patients.METHODS In a 2-year observational study,146 non-obese KOA patients of 35-60 years were evaluated clinically(Knee injury and Osteoarthritis Outcome Score,KOOS)and radiologically(Kellegren-Lawrence stage,KL).The serum 25(OH)D level of these patients and 146 normal healthy individuals of same age group were estimated.RESULTS Both the groups were comparable in terms of age and sex.The average serum 25(OH)D level in healthy individuals and KOA patients was 45.83 ng/mL and 34.58 ng/mL,respectively(P<0.001).Inadequate serum 25(OH)D level(<30 ng/mL)was found in 46.57%of KOA patients and 24%of normal healthy participants indicating a significant positive association(odds ratio 2.77,95%CI:1.67-4.54,P<0.001).The 25(OH)D level in KL grade I,II,III and IV was 43.40,30.59,31.56 and 33.93 ng/mL respectively(no difference,P=0.47).Similarly,the KOOS score in sufficient,insufficient and deficient groups were 65.31,60.36 and 65.31,respectively(no difference,P=0.051).CONCLUSION The serum 25(OH)D level is significantly low in younger KOA patients.However,the clinical and radiological severities have no association with serum vitamin D level.

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.