Aims

Simultaneous bilateral total knee arthroplasty (TKA) has been used due to its financial advantages, overall resource usage, and convenience for the patient. The training model where a trainee performs the first TKA, followed by the trainer surgeon performing the second TKA, is a unique model to our institution. This study aims to analyze the functional and clinical outcomes of bilateral simultaneous TKA when performed by a trainee or a supervising surgeon, and also to assess these outcomes based on which side was done by the trainee or by the surgeon.

Aims

The purpose is to determine the non-inferiority of a smartphone-based exercise educational care management system after primary knee arthroplasty compared with a traditional in-person physiotherapy rehabilitation model.

Aims

To investigate whether chronic kidney disease (CKD) is associated with the risk of all-cause revision or revision due to a periprosthetic joint infection (PJI) after primary hip or knee arthroplasty.

Aims

This study compares the PFC total knee arthroplasty (TKA) system in a prospective randomized control trial (RCT) of the mobile-bearing rotating-platform (RP) TKA against the fixed-bearing (FB) TKA. This is the largest RCT with the longest follow-up where cruciate-retaining PFC total knee arthroplasties are compared in a non-bilateral TKA study.

For 3 decades surgeons have vigorously debated whether it is reasonable to offer simultaneous bilateral total knee replacement (TKA) to patients. Even after this substantial period of time there remain no randomised clinical trials that have addressed this issue and thus, it remains difficult to fully evaluate both the relative risks and the absolute risks of bilateral simultaneous versus staged bilateral knee replacement. What has emerged over the past couple of decades, however, is an understanding that there is a subset of patients with substantial comorbidities such as pre-existent cardiac disease and advanced age for whom bilateral simultaneous knee replacement seems unwise. For younger or otherwise healthy patients the debate continues in 2016 and seems to be focused less on the data itself than on how individual surgeons come to reconcile the differences between Relative Risk and Absolute Risk. When data is pooled from multiple retrospective studies of simultaneous versus staged bilateral TKA there are 2 clear trends that appear in the data. First, the relative risk of certain substantial complications (cardiac, thromboembolic, neurologic, gastrointestinal, and death) seems to be higher after simultaneous bilateral TKA than after staged bilateral TKA. Oakes and Hanssen highlighted these differences in Relative Risk noting that for each of those 5 outcomes there was a 2 to 5 times greater incidence of these complications after bilateral versus unilateral TKA. At the same time, however, it is clear that for most medically uncomplicated patients the Absolute Risk of a major complication is still fairly low — it is likely that >93% of such patients can undergo simultaneous bilateral TKA without encountering a major complication. Individual surgeons and individual patients often view those kinds of statistics in markedly disparate ways. One set of surgeons and patients will view the Relative Risk as most important and be decidedly concerned about the 2–5 times higher risk of certain complications. Another set of patients and surgeons will look at the Absolute Risk as most important and determine that it is decidedly most likely (>93%) that an individual healthy patient will make it through bilateral simultaneous TKA without major medical complications. Overall the conclusions of Oakes and Hanssen from a decade ago remain relevant in 2016: the overall risk of a peri-operative complication is higher with simultaneous bilateral TKA … and this is particularly true for the risk of peri-operative death. While some surgeons and some patients will decide that the increases in Relative Risk is offset by the fairly low Absolute Risk of complications and thus, feel comfortable with bilateral simultaneous TKA, other patients and other surgeons will not

Introduction. Bilateral total knee replacement can either be simultaneous, in which both knees are operated in the same sitting, in one day, or staged, in which both knees are operated but not on the same day. With appropriate patient selection, the potential benefits of conducting this procedure in a simultaneous fashion outweigh the possible risks of the procedure. Very few studies have evaluated the results of bilateral knee replacement in a single sitting in Indian population. Objectives. To determine the functional outcome after simultaneous knee replacement and assessment of the peri and post operative complications. Methods. Patients undergoing bilateral total knee arthroplasty in a single sitting by a single surgeon using standard technique and posterior stabilized cruciate substituting prosthesis. Evaluation was done using Hospital for Special Surgery Knee and Function scores. Results. The mean knee score improved to 85.81 from 67.83 and the mean function score improved to 83.15 from 69.14. Post operative complications included two cases of acute coronary syndrome, one case of psychosis and another of opiod withdrawal. Conclusions. Simultaneous bilateral total knee replacement remains an appropriate option in select patients

Introduction. The sit-to-stand (STS) movement is a physically demanding activity of daily living and is performed more than 50 times per day in healthy adults. Several studies have shown that the normal ‘screw-home’ mechanism is altered after total knee arthroplasty (TKA). However, these studies have been criticized due to their limitations of the movement being non-weight-bearing or atypical daily activity (lunge maneuver). We analyzed TKA subjects during a STS activity to determine if the internal-external rotation of their TKA knees differed from the knees of control subjects. Materials and Methods. Six TKA subjects (3 M, 3 F) participated following institutional review board approval and informed consent. One subject had bilateral knee replacement. Surgery was performed by the same surgeon using the same type of implant (6 posterior-stabilized, 1 cruciate-retaining). The control group included eight healthy subjects (6 M, 2 F). Retro-reflective markers were placed over bony landmarks of the torso, pelvis, and lower extremities, and arrays of four markers were attached to the thighs and shanks using elastic wrap. A digitizing pointer was used to create virtual markers at the anterior superior iliac spines. A nine camera video-based opto-electronic system (Qualisys) was used for 3D motion capture. Subjects were barefoot and seated on a 46 cm armless bench with one foot on each force plate (AMTI). Subjects rose from their seated position, paused, and returned to the seated position at a self-selected pace repeatedly for 30 seconds. Subjects did not use their arms to push off the bench. Only the STS portion of the task was analyzed. The start of the STS cycle was defined when the C7 marker began to move forward in the sagittal plane and ended at the point of maximum knee extension. Only the right leg of the control subjects was used for analysis. Results. Femurs rotated internally as control subjects rose from the bench. Two of the TKA knees displayed a similar pattern of internal rotation as the knees extended. However, four TKA knees displayed the opposite pattern, and one TKA knee showed no rotation. For ease of comparison I/E rotation was normalized to zero at full extension (Figure 1). Discussion. Our results of a reverse tibio-femoral rotational pattern in TKA knees compared to normal knees are similar to those reported in fluoroscopic studies in which a single leg lunge activity is performed. Finding a similar reversal in STS is significant due to the necessity and frequency of the STS activity during daily living and warrants further investigation

Introduction. In a previous study of subjects with no history of lower extremity injury or disease we found a linear relationship between body weight and peak hip, knee, and ankle joint forces during the stance phase of gait. To investigate the effect of total knee arthroplasty (TKA) on forces in the operated joints as well as the other joints of the lower extremities, we tested TKA subjects during gait and performed inverse dynamics analyses of the results. Materials and Methods. TKA subjects (3 M, 1 F; 58 ± 5 years; body mass index range (BMI): 26–36 kg/m. 2. ) participated in this investigation following institutional review board approval and informed consent. One subject had bilateral knee replacement. Each patient received the same implant design (4 PS, 1 CR). Data from previously tested control subjects (8 M, 4 F; 26 ± 4 years; BMI: 20–36 kg/m. 2. ) were used for comparison. Retro-reflective markers were placed over bony landmarks of each subject. A nine-camera video-based opto-electronic system was used for 3D motion capture as subjects walked barefoot at a self-selected speed on a 10 meter walkway instrumented with three force plates. Data were imported into a 12-body segment multibody dynamics model (AnyBody Technology) to calculate joint forces. Each leg contained 56 muscles whose mechanical effect was modeled by 159 simple muscle slips, each consisting of a contractile element. The models were scaled to match each subject's anthropometry and BMI. For the control subjects, only one limb was used in determining the relationship between body mass and peak joint force at the hip, knee, and ankle. For the TKA subjects, the peak joint forces were calculated for both the TKA limb and the contralateral limb. Results. Figure 1 shows the knee joint forces for the TKA subjects’ operated (red triangles) and contralateral knees (diamonds) along with the values for the control subjects (circles). Knee joint forces for the TKA subjects fell within or near the upper and lower 95% confidence intervals (dashed lines) of the mean regression lines (solid lines) for the control subjects. Three patients had other lower limb complications (osteoarthritis, ankle surgery). One subject favored the operated limb and another the non-operated limb, as ascertained from the corresponding hip (Figure 2) and ankle joint forces (Figure 3). Discussion. Modeling and simulation can be used to indirectly estimate joint forces in the implanted and non-operated joints. Our gait-lab derived inverse dynamics simulations suggest that joint forces following TKA fall within or near the normal range over a wide range of body weights and that the linear dependence between joint force and body weight applies to the implanted as well as non-implanted joints

Introduction:. The safety of simultaneous bilateral knee replacement (BTKA) remains controversial. Some studies have proposed a higher incidence of serious complications, even death, following BTKA whilst others refute the latter. The objective of this meta-analysis was to evaluate the safety of BTKA. Methods:. A computerised literature search was conducted to identify all citations, between 1966 to 2005, concerning BTKA. All the English-language abstracts were obtained. A multistage assessment was then used to identify articles fulfilling the inclusion criteria for the study. All randomised, prospective studies reporting the outcome of BTKA were included. Details of any reported data were extracted and extensive analysis of relevant variables carried out. Results:. 150 published articles pertaining to BTKA were identified of which 18 papers on 27,807 patients (44,684 knees) were included in the meta-analysis. 10,734 cases were unilateral TKA, 16,378 were simultaneous BTKA and 458 were staged bilateral TKA with at least 3 months’ time duration between the surgical procedures. The complications analyzed were DVT, PE, cardiac events and mortality. The incidence of PE (OR=1.8), cardiac complications (OR=2.4), and mortality (OR=2.24) were higher after simultaneous BTKA. The incidence of DVT was LOWER in the group with simultaneous BTKA. Discussion:. Based on the findings of this meta-analysis, simultaneous BTKA seems to carry a higher risk of serious cardiac complications, pulmonary complications, and mortality. This procedure should be reserved for the healthy and young patients

To consider bilateral simultaneous knee replacement, both knees must have significant structural damage. It is best if the patient can't decide which knee is more bothersome. In borderline cases, ask the patient to pretend that the worse knee is normal and if so, would they be seeing you for consideration of knee replacement on the less involved side. If the answer to this question is “yes,” consider the patient a potential candidate for bilateral knee replacement. If the answer is “no,” recommend operating only on the worse knee, and expect that the operation on the second knee can probably be delayed for a considerable period of time. Strong indications for bilateral simultaneous TKA are bilateral severe angular deformity, bilateral severe flexion contracture, and anesthesia difficulties, i.e., patients who are anatomically or medically difficult to anesthetise, such as some adult or juvenile rheumatoid arthritis patients or patients with severe ankylosing spondylitis. Relative indications for bilateral simultaneous TKA include the need for multiple additional surgical procedures to achieve satisfactory function and financial or social considerations for the patient. Contraindications to bilateral TKA include medical infirmity (especially cardiac), a reluctant patient, and a patient with a very low pain threshold. When performing bilateral simultaneous TKA, both limbs are prepped and draped at the same time. An initial dose of an intravenous antibiotic is given (usually 1g of a cephalosporin) before inflation of the tourniquet. Surgery begins on the more symptomatic side or on either side if neither knee is significantly worse than the other. The reason for starting on the more symptomatic side is in case surgery has to be discontinued after only one procedure owing to anesthetic considerations. After the components have been implanted on the first side, the tourniquet is deflated and a second dose of intravenous antibiotic is administered (usually 500mg of a cephalosporin). After the joint capsule is closed and flexion against gravity is measured, one team completes the subcutaneous and skin closure on the first side while the other team inflates the second tourniquet and begins the exposure of the second side. When the second tourniquet is deflated, a third dose of antibiotic is given (usually 500mg of a cephalosporin for a total dose of 2g for both knees). Because of concern about the potential for cross-contamination of the knee wounds when instruments used during the final stages of skin closure on the first knee are maintained on the field and used on the second knee, they should probably be handed off the field and outer surgical gloves changed. Most patients will report after their complete recovery that they are glad they did both knees at the same time. A patient who has any uncertainty about proceeding with bilateral surgery should have only one knee done at a time. In many cases, the second side receives a “reprieve,” becoming more tolerable after the first side has been operated on

Introduction. The safety of simultaneous bilateral knee replacement (BTKA) remains controversial. Some studies have proposed a higher incidence of serious complications, even death, following BTKA whilst others refute the latter. The objective of this meta-analysis was to evaluate the safety of BTKA. Methods. A computerised literature search was conducted to identify all citations, between 1966 to 2005, concerning BTKA. All the English-language abstracts were obtained. A multistage assessment was then used to identify articles fulfilling the inclusion criteria for the study. All randomised, prospective studies reporting the outcome of BTKA were included. Details of any reported data were extracted and extensive analysis of relevant variables carried out. Results. 150 published articles pertaining to BTKA were identified of which 18 papers on 27,807 patients (44,684 knees) were included in the meta-analysis. 10,734 cases were unilateral TKA, 16,378 were simultaneous BTKA and 458 were staged bilateral TKA with at least 3 months time duration between the surgical procedures. The complications analysed were DVT, PE, cardiac events and mortality. The incidence of PE (OR=1.8), cardiac complications (OR=2.4), and mortality (OR=2.24) were higher after simultaneous BTKA. The incidence of DVT was LOWER in the group with simultaneous BTKA. Discussion. Based on the findings of this meta-analysis, simultaneous BTKA seems to carry a higher risk of serious cardiac complications, pulmonary complications, and mortality. This procedure should be reserved for the healthy and young patients

To consider bilateral simultaneous knee replacement, both knees must have significant structural damage. It is best if the patient can't decide which knee is more bothersome. In borderline cases, ask the patient to pretend that the worse knee is normal and if so, would they be seeing you for consideration of knee replacement on the less involved side. If the answer to this question is “yes,” consider the patient a potential candidate for bilateral knee replacement. If the answer is “no,” recommend operating only on the worse knee, and expect that the operation on the second knee can probably be delayed for a considerable period of time. Strong indications for bilateral simultaneous TKA are bilateral severe angular deformity, bilateral severe flexion contracture, and anesthesia difficulties, i.e., patients who are anatomically or medically difficult to anesthetise, such as some adult or juvenile rheumatoid arthritis patients or patients with severe ankylosing spondylitis. Relative indications for bilateral simultaneous TKA include the need for multiple additional surgical procedures to achieve satisfactory function and financial or social considerations for the patient. Contraindications to bilateral TKA include medical infirmity (especially cardiac), a reluctant patient, and a patient with a very low pain threshold. When performing bilateral simultaneous TKA, both limbs are prepped and draped at the same time. An initial dose of an intravenous antibiotic is given (usually 1 gram of a cephalosporin) before inflation of the tourniquet. Surgery begins on the more symptomatic side or on either side if neither knee is significantly worse than the other. The reason for starting on the more symptomatic side is in case surgery has to be discontinued after only one procedure owing to anesthetic considerations. After the components have been implanted on the first side, the tourniquet is deflated and a second dose of intravenous antibiotic is administered (usually 500 mg of a cephalosporin). After the joint capsule is closed and flexion against gravity is measured, one team completes the subcutaneous and skin closure on the first side while the other team inflates the second tourniquet and begins the exposure of the second side. When the second tourniquet is deflated, a third dose of antibiotic is given (usually 500 mg of a cephalosporin for a total dose of 2 g for both knees). Because of concern about the potential for cross-contamination of the knee wounds when instruments used during the final stages of skin closure on the first knee are maintained on the field and used on the second knee, they should probably be handed off the field and outer surgical gloves changed. Most patients will report after their complete recovery that they are glad they did both knees at the same time. A patient who has any uncertainty about proceeding with bilateral surgery should have only one knee done at a time. In many cases, the second side receives a “reprieve,” becoming more tolerable after the first side has been operated on

Early and accurate prediction of hospital length-of-stay (LOS) in patients undergoing knee replacement is important for economic and operational reasons. Few studies have systematically developed a multivariable model to predict LOS. We performed a retrospective cohort study of 1609 patients aged ≥ 50 years who underwent elective, primary total or unicompartmental knee replacements. Pre-operative candidate predictors included patient demographics, knee function, self-reported measures, surgical factors and discharge plans. In order to develop the model, multivariable regression with bootstrap internal validation was used. The median LOS for the sample was four days (interquartile range 4 to 5). Statistically significant predictors of longer stay included older age, greater number of comorbidities, less knee flexion range of movement, frequent feelings of being down and depressed, greater walking aid support required, total (versus unicompartmental) knee replacement, bilateral surgery, low-volume surgeon, absence of carer at home, and expectation to receive step-down care. For ease of use, these ten variables were used to construct a nomogram-based prediction model which showed adequate predictive accuracy (optimism-corrected R² = 0.32) and calibration. If externally validated, a prediction model using easily and routinely obtained pre-operative measures may be used to predict absolute LOS in patients following knee replacement and help to better manage these patients.

Cite this article: Bone Joint J 2013;95-B:1490–6.

Blood loss during total knee replacement (TKR) remains a significant concern. In this study, 114 patients underwent TKR, and were divided into two groups based on whether they received a new generation fibrin sealant intra-operatively, or a local infiltration containing adrenaline. Groups were then compared for mean calculated total blood volume (TBV) loss, transfusion rates, and knee range of movement. Mean TBV loss was similar between groups: fibrin sealant mean was 705 ml (281 to 1744), local adrenaline mean was 712 ml (261 to 2308) (p = 0.929). Overall, significantly fewer units of blood were transfused in the fibrin sealant group (seven units) compared with the local adrenaline group (15 units) (p = 0.0479). Per patient transfused, significantly fewer units of blood were transfused in the fibrin sealant group (1.0 units) compared with the local adrenaline group (1.67 units) (p = 0.027), suggesting that the fibrin sealant may reduce the need for multiple unit transfusions. Knee range of movement was similar between groups. From our results, it appears that application of this newer fibrin sealant results in blood loss and transfusion rates that are low and similar to previously applied fibrin sealants.

Cite this article: Bone Joint J 2013;95-B, Supple A:135–9.

Staged bilateral total knee arthroplasty is performed increasingly frequently but no data has been published comparing the specific outcome for the first knee replacement to that of the second. Pre-operative and post-operative Oxford Knee Scores (/ 48) were reviewed for each knee in a series of 91 patients undergoing staged bilateral total knee arthroplasty over a 5-year period. Pre-operative scores for the first total knee arthroplasty were significantly worse with a mean of 14.9 in comparison to 17.0 for the second knee (P=0.0083). While there was no significant difference between the mean post-operative scores for the first knee (37.4) and the second knee (36.6) (P=0.195), the mean improvement was significantly less for the second knee (22.6 points versus 19.6 points) (P=0.0045). Our results demonstrate that in patients undergoing staged bilateral knee arthroplasty, the second knee replacement is commonly performed at a lower threshold and functional improvement is less than for the first knee. This data will be important to inform the expectations of patients considering proceeding to bilateral knee arthroplasty after previously having undergone a primary total knee replacement

Intra-operative, peri-articular injection of local anaesthesia is an increasingly popular way of controlling pain following total knee replacement. At the same time, the problems associated with allogenic blood transfusion have led to interest in alternative methods for managing blood loss after total knee replacement, including the use of auto-transfusion of fluid from the patient’s surgical drain. It is safe to combine peri-articular infiltration with auto-transfusion from the drain. We performed a randomised clinical trial to compare the concentration of local anaesthetic in the blood and in the fluid collected in the knee drain in patients having either a peri-articular injection or a femoral nerve block. Clinically relevant concentrations of local anaesthetic were found in the fluid from the drains of patients having peri-articular injections (4.92 μg/ml (sd 3.151)). However, none of the patients having femoral nerve blockade had detectable levels. None of the patients in either group had clinically relevant concentrations of local anaesthetic in their blood after re-transfusion.

The evidence from this study suggests that it is safe to use peri-articular injection in combination with auto-transfusion of blood from peri-articular drains during knee replacement surgery.

The aim of this study was to compare the outcome of cemented TKR using either oxidized zirconium (oxinium) or cobalt chrome (CoCr) femoral components in patients undergoing simultaneous bilateral TKR. Patients involved in the study received one of each prosthesis, thereby acting as their own control. The hypothesis was that there would be no difference in the clinical and radiographic outcome between the two prosthetic materials.

Forty consecutive patients who were undergoing bilateral Genesis ll TKR consented to participate in the study. Patients were assessed preoperatively, at five days, six weeks and one, two and five years, postoperatively. The outcome measures included the KOOS, Knee Society Score, BOA Patient Satisfaction Scale, and radiographs at six weeks and one, two and five years. In two patients polyethlylene exchange was performed at 56 months from surgery during patellofemoral resurfacing. The four retrieved polyethylene liners were studied for wear with the aid of a stereo zoom microscope and an environmental scanning electron microscope (ESEM). Both the patients and the all examiners were blinded as to the prosthesis type throughout the study.

Forty patients (80 knees) were included in the study. At five years, three patients were deceased and two had developed senile dementia. No patients were lost to follow up. At five years from surgery the CoCr knee was preferred by 41% of patients compared to 13% who preferred the Oxinium knee (p=0.009). There was no significant difference in range of motion between the two prosthesis at five days, six weeks or one, two and five years. There were also no significant differences between the two prostheses in any of the other variables assessed. The four retrieved polyethylene inserts showed similar patterns of wear in terms of both wear types and patterns under examination with both the stereo zoom and scanning electron microscope with no clear differences between CoCr and Oxinium bearing against the polyethlylene. There was no difference in the grade or incidence of radiographic lucencies between the two prosthesis at five years.

At five years after surgery the only significant difference between the Genesis II Oxinium prosthesis and the CoCr prosthesis was a subjective preference for the CoCr prosthesis by a higher proportion of patients. There were no unexpected complications associated with the use the Oxinium femoral implants. In the four retrieved polyethylene liners, no significant differences were identified between the two prosthesis materials in terms of detectable wear type and patterns. Continued follow up of this cohort is planned to establish whether Oxinium femoral implants have an improved survivorship compared to CoCr femoral component in total knee replacement to warrant the additional cost.

Introduction. The aim of this study was to compare the outcome between the first and second knee replacement in patients undergoing staged bilateral total knee arthroplasty. Methods. A prospective database of outcomes of knee replacements performed at Broadgreen Hospital was commenced in 2003. Data is collected pre operatively, 3 and 12 months post operatively and every two years thereafter. We identified 64 patients (26 male, 38 female) who had bilateral knee replacements and had at least one year post operative outcome studies. Data on pain scores, walking ability (score 1-6), use of walking aids (score 1-6), range of movement, instability, muscle strength, WOMAC scores, SF-12 scores, the Knee Society Radiological Score and length of hospital stay were identified. We compared data between the first and second knee operation. Results. Groups remained statistically comparable between the 1st and 2nd operation. Average score for post op walking ability was 4.83 (2. nd. knee) vs 4.51 (1. st. knee) (p=0.03). Average score for post op walking aid requirement was 5.73 (2. nd. knee) vs 5.46 (1. st. knee) (p=0.01). Patient's post op SF-12 scores were 54.26 (2. nd. knee) vs 52.45 (1. st. knee) (p=0.04). Average hospital stay was 4.73 (2. nd. Knee) vs 6.06 (1. st. knee) (p=0.05). All other data comparison was statistically insignificant. Conclusion. Patients have reduced hospital stay and continue to improve after the second procedure with regards to walking ability, use of walking aids and psychological well being. This may be because having the worst knee replaced first means improved walking ability and decreased need for walking aids after the second operation. Also patients have already experienced one knee replacement and therefore are less apprehensive and more familiar with the post operative physiotherapy and rehabilitation programme