This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up. From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed.Aims
Methods
Unicompartmental knee arthroplasty (UKA) is the preferred treatment for anterior medial knee osteoarthritis (OA) owing to the rapid postoperative recovery. However, the risk factors for UKA failure remain controversial. The clinical data of Oxford mobile-bearing UKAs performed between 2011 and 2017 with a minimum follow-up of five years were retrospectively analyzed. Demographic, surgical, and follow-up data were collected. The Cox proportional hazards model was used to identify the risk factors that contribute to UKA failure. Kaplan-Meier survival was used to compare the effect of the prosthesis position on UKA survival.Aims
Methods
Obtaining solid implant fixation is crucial in revision total knee arthroplasty (rTKA) to avoid aseptic loosening, a major reason for re-revision. This study aims to validate a novel grading system that quantifies implant fixation across three anatomical zones (epiphysis, metaphysis, diaphysis). Based on pre-, intra-, and postoperative assessments, the novel grading system allocates a quantitative score (0, 0.5, or 1 point) for the quality of fixation achieved in each anatomical zone. The criteria used by the algorithm to assign the score include the bone quality, the size of the bone defect, and the type of fixation used. A consecutive cohort of 245 patients undergoing rTKA from 2012 to 2018 were evaluated using the current novel scoring system and followed prospectively. In addition, 100 first-time revision cases were assessed radiologically from the original cohort and graded by three observers to evaluate the intra- and inter-rater reliability of the novel radiological grading system.Aims
Methods
Robotic arm-assisted surgery offers accurate and reproducible guidance in component positioning and assessment of soft-tissue tensioning during knee arthroplasty, but the feasibility and early outcomes when using this technology for revision surgery remain unknown. The objective of this study was to compare the outcomes of robotic arm-assisted revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) versus primary robotic arm-assisted TKA at short-term follow-up. This prospective study included 16 patients undergoing robotic arm-assisted revision of UKA to TKA versus 35 matched patients receiving robotic arm-assisted primary TKA. In all study patients, the following data were recorded: operating time, polyethylene liner size, change in haemoglobin concentration (g/dl), length of inpatient stay, postoperative complications, and hip-knee-ankle (HKA) alignment. All procedures were performed using the principles of functional alignment. At most recent follow-up, range of motion (ROM), Forgotten Joint Score (FJS), and Oxford Knee Score (OKS) were collected. Mean follow-up time was 21 months (6 to 36).Aims
Methods
The aim of this study was to evaluate whether achieving medial joint opening, as measured by the change in the joint line convergence angle (∆JLCA), is a better predictor of clinical outcomes after high tibial osteotomy (HTO) compared with the mechanical axis deviation, and to find individualized targets for the redistribution of load that reflect bony alignment, joint laxity, and surgical technique. This retrospective study analyzed 121 knees in 101 patients. Patient-reported outcome measures (PROMs) were collected preoperatively and one year postoperatively, and were analyzed according to the surgical technique (opening or closing wedge), postoperative mechanical axis deviation (deviations above and below 10% from the target), and achievement of medial joint opening (∆JLCA > 1°). Radiological parameters, including JLCA, mechanical axis deviation, and the difference in JLCA between preoperative standing and supine radiographs (JLCAPD), an indicator of medial soft-tissue laxity, were measured. Cut-off points for parameters related to achieving medial joint opening were calculated from receiver operating characteristic (ROC) curves.Aims
Methods
To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration. The OCD lesion was created on the trochlear groove of left articular cartilage of femur per rat (40 rats in total). The experimental groups were Sham, OCD, and ESWT (0.25 mJ/mm2, 800 impulses, 4 Hz). The animals were euthanized at 2, 4, 8, and 12 weeks post-treatment, and histopathological analysis, micro-CT scanning, and immunohistochemical staining were performed for the specimens.Aims
Methods
This study aimed to analyze kinematics and kinetics of the tibiofemoral joint in healthy subjects with valgus, neutral, and varus limb alignment throughout multiple gait activities using dynamic videofluoroscopy. Five subjects with valgus, 12 with neutral, and ten with varus limb alignment were assessed during multiple complete cycles of level walking, downhill walking, and stair descent using a combination of dynamic videofluoroscopy, ground reaction force plates, and optical motion capture. Following 2D/3D registration, tibiofemoral kinematics and kinetics were compared between the three limb alignment groups.Aims
Methods
The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery. A total of 76 patients (34 bi-UKA and 42 TKA patients) were analyzed in a prospective, single-centre, randomized controlled trial. Flat ground shod gait analysis was performed preoperatively and one year postoperatively. Knee flexion moment was calculated from motion capture markers and force plates. The same setup determined proprioception outcomes during a joint position sense test and one-leg standing. Surgery allocation, surgeon, and secondary outcomes were analyzed for prediction of the primary outcome from a binary regression model.Aims
Methods
In total knee arthroplasty (TKA), blood loss continues internally after surgery is complete. Typically, the total loss over 48 postoperative hours can be around 1,300 ml, with most occurring within the first 24 hours. We hypothesize that the full potential of tranexamic acid (TXA) to decrease TKA blood loss has not yet been harnessed because it is rarely used beyond the intraoperative period, and is usually withheld from ‘high-risk’ patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease, a patient group who would benefit greatly from a reduced blood loss. TRAC-24 was a prospective, phase IV, single-centre, open label, parallel group, randomized controlled trial on patients undergoing TKA, including those labelled as high-risk. The primary outcome was indirect calculated blood loss (IBL) at 48 hours. Group 1 received 1 g intravenous (IV) TXA at the time of surgery and an additional 24-hour postoperative oral regime of four 1 g doses, while Group 2 only received the intraoperative dose and Group 3 did not receive any TXA.Aims
Methods
Anterior cruciate ligament (ACL) rupture commonly leads to post-traumatic osteoarthritis, regardless of surgical reconstruction. This study uses standing MRI to investigate changes in contact area, contact centroid location, and tibiofemoral alignment between ACL-injured knees and healthy controls, to examine the effect of ACL reconstruction on these parameters. An upright, open MRI was used to directly measure tibiofemoral contact area, centroid location, and alignment in 18 individuals with unilateral ACL rupture within the last five years. Eight participants had been treated nonoperatively and ten had ACL reconstruction performed within one year of injury. All participants were high-functioning and had returned to sport or recreational activities. Healthy contralateral knees served as controls. Participants were imaged in a standing posture with knees fully extended.Aims
Methods
This study aimed to investigate the relationship between changes in patellar height and clinical outcomes at a mean follow-up of 7.7 years (5 to 10) after fixed-bearing posterior-stabilized total knee arthroplasty (PS-TKA). We retrospectively evaluated knee radiographs of 165 knees, which underwent fixed-bearing PS-TKA with patella resurfacing. The incidence of patella baja and changes in patellar height over a minimum of five years of follow-up were determined using Insall-Salvati ratio (ISR) measurement. We examined whether patella baja (ISR < 0.8) at final follow-up affected clinical outcomes, knee joint range of motion (ROM), and Knee Society Score (KSS). We also assessed inter- and intrarater reliability of ISR measurements and focused on the relationship between patellar height reduction beyond measurement error and clinical outcomes.Aims
Methods
Medial pivot (MP) total knee arthroplasties (TKAs) were designed to mimic native knee kinematics with their deep medial congruent fitting of the tibia to the femur almost like a ball-on-socket, and a flat lateral part. GMK Sphere is a novel MP implant. Our primary aim was to study the migration pattern of the tibial tray of this TKA. A total of 31 patients were recruited to this single-group radiostereometric analysis (RSA) study and received a medial pivot GMK Sphere TKA. The distributions of male patients versus female patients and right versus left knees were 21:10 and 17:14, respectively. Mean BMI was 29 kg/m2 (95% confidence interval (CI) 27 to 30) and mean age at surgery was 63 years (95% CI 61 to 66). Maximum total point motions (MTPMs), medial, proximal, and anterior translations and transversal, internal, and varus rotations were calculated at three, 12, and 24 months. Patient-reported outcome measure data were also retrieved.Aims
Methods
The objective of this study was to compare the two-year migration pattern and clinical outcomes of a total knee arthroplasty (TKA) with an asymmetrical tibial design (Persona PS) and a well-proven TKA with a symmetrical tibial design (NexGen LPS). A randomized controlled radiostereometric analysis (RSA) trial was conducted including 75 cemented posterior-stabilized TKAs. Implant migration was measured with RSA. Maximum total point motion (MTPM), translations, rotations, clinical outcomes, and patient-reported outcome measures (PROMs) were assessed at one week postoperatively and at three, six, 12, and 24 months postoperatively.Aims
Methods
Current guidelines consider analyses of joint aspirates, including leucocyte cell count (LC) and polymorphonuclear percentage (PMN%) as a diagnostic mainstay of periprosthetic joint infection (PJI). It is unclear if these parameters are subject to a certain degree of variability over time. Therefore, the aim of this study was to evaluate the variation of LC and PMN% in patients with aseptic revision total knee arthroplasty (TKA). We conducted a prospective, double-centre study of 40 patients with 40 knee joints. Patients underwent joint aspiration at two different time points with a maximum period of 120 days in between these interventions and without any events such as other joint aspirations or surgeries. The main indications for TKA revision surgery were aseptic implant loosening (n = 24) and joint instability (n = 11).Aims
Methods
The aims of this study were to evaluate wear on the surface of cobalt-chromium (CoCr) femoral components used in total knee arthroplasty (TKA) and compare the wear of these components with that of ceramic femoral components. Optical profilometry was used to evaluate surface roughness and to examine the features created by the wear process in a knee wear simulator. We developed a method of measuring surface changes on five CoCr femoral components and quantifying the loss of material from the articular surface during the wear process. We also examined the articular surface of three ceramic femoral components from a previous test for evidence of surface damage, and compared it with that of CoCr components.Aims
Methods
To describe the risk of periprosthetic joint infection (PJI) and reoperation in patients who have an acute, traumatic wound dehiscence following total knee arthroplasty (TKA). From January 2002 to December 2018, 16,134 primary TKAs were performed at a single institution. A total of 26 patients (0.1%) had a traumatic wound dehiscence within the first 30 days. Mean age was 68 years (44 to 87), 38% (n = 10) were female, and mean BMI was 34 kg/m2 (23 to 48). Median time to dehiscence was 13 days (interquartile range (IQR) 4 to 15). The dehiscence resulted from a fall in 22 patients and sudden flexion after staple removal in four. The arthrotomy was also disrupted in 58% (n = 15), including a complete extensor mechanism disruption in four knees. An irrigation and debridement with component retention (IDCR) was performed within 48 hours in 19 of 26 knees and two-thirds were discharged on antibiotic therapy. The mean follow-up was six years (2 to 15). The association of wound dehiscence and the risk of developing a PJI was analyzed.Aims
Methods
The primary aim of this study was to assess whether non-fatal postoperative venous thromboembolism (VTE) within six months of surgery influences the knee-specific functional outcome (Oxford Knee Score (OKS)) one year after total knee arthroplasty (TKA). Secondary aims were to assess whether non-fatal postoperative VTE influences generic health and patient satisfaction at this time. A study of 2,393 TKAs was performed in 2,393 patients. Patient demographics, comorbidities, OKS, EuroQol five-dimension score (EQ-5D), and Forgotten Joint Score (FJS) were collected preoperatively and one year postoperatively. Overall patient satisfaction with their TKA was assessed at one year. Patients with VTE within six months of surgery were identified retrospectively and compared with those without.Aims
Methods
In the last decade, interest in partial knee arthroplasties and bicruciate retaining total knee arthroplasties has increased. In addition, patient-related outcomes and functional results such as range of movement and ambulation may be more promising with less invasive procedures such as bicompartmental arthroplasty (BCA). The purpose of this study is to evaluate clinical and radiological outcomes after a third-generation patellofemoral arthroplasty (PFA) combined with a medial or lateral unicompartmental knee arthroplasty (UKA) at mid- to long-term follow-up. A total of 57 procedures were performed. In 45 cases, a PFA was associated with a medial UKA and, in 12, with a lateral UKA. Patients were followed with validated patient-reported outcome measures (Oxford Knee Score (OKS), EuroQol five-dimension questionnaire (EQ-5D), EuroQoL Visual Analogue Scale (EQ-VAS)), the Knee Society Score (KSS), the Forgotten Joint Score (FJS), and radiological analysis.Aims
Methods
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. A multicentre prospective randomized controlled trial was conducted evaluating the use of a smartphone-based care management system for primary total knee arthroplasty (TKA) and partial knee arthroplasty (PKA). Patients in the control group (n = 244) received the respective institution’s standard of care with formal physiotherapy. The treatment group (n = 208) were provided a smartwatch and smartphone application. Early outcomes assessed included 90-day knee range of movement, EuroQoL five-dimension five-level score, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) score, 30-day single leg stance (SLS) time, Time up and Go (TUG) time, and need for manipulation under anaesthesia (MUA).Aims
Methods
Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA). Two-stage revision has traditionally been considered the gold standard of treatment for established infection, but increasing evidence is emerging in support of one-stage exchange for selected patients. The objective of this study was to determine the outcomes of single-stage revision TKA for PJI, with mid-term follow-up. A total of 84 patients, with a mean age of 68 years (36 to 92), underwent single-stage revision TKA for confirmed PJI at a single institution between 2006 and 2016. In all, 37 patients (44%) were treated for an infected primary TKA, while the majority presented with infected revisions: 31 had undergone one previous revision (36.9%) and 16 had multiple prior revisions (19.1%). Contraindications to single-stage exchange included systemic sepsis, extensive bone or soft-tissue loss, extensor mechanism failure, or if primary wound closure was unlikely to be achievable. Patients were not excluded for culture-negative PJI or the presence of a sinus.Aims
Methods
The mobile bearing Oxford unicompartmental knee arthroplasty (OUKA) is recommended to be performed with the leg in the hanging leg (HL) position, and the thigh placed in a stirrup. This comparative cadaveric study assesses implant positioning and intraoperative kinematics of OUKA implanted either in the HL position or in the supine leg (SL) position. A total of 16 fresh-frozen knees in eight human cadavers, without macroscopic anatomical defects, were selected. The knees from each cadaver were randomized to have the OUKA implanted in the HL or SL position.Aims
Methods
The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups. This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned postioning of the components in both groups.Aims
Methods
Stiffness is a common complication after total knee arthroplasty (TKA). Pathogenesis is not understood, treatment options are limited, and diagnosis is challenging. The aim of this study was to investigate if MRI can be used to visualize intra-articular scarring in patients with stiff, painful knee arthroplasties. Well-functioning primary TKAs (n = 11), failed non-fibrotic TKAs (n = 5), and patients with a clinical diagnosis of fibrosisAims
Methods
Total knee arthroplasty is an established treatment for knee osteoarthritis with excellent long-term results, but there remains controversy about the role of uncemented prostheses. We present the long-term results of a randomized trial comparing an uncemented tantalum metal tibial component with a conventional cemented component of the same implant design. Patients under the age of 70 years with symptomatic osteoarthritis of the knee were randomized to receive either an uncemented tantalum metal tibial monoblock component or a standard cemented modular component. The mean age at time of recruitment to the study was 63 years (50 to 70), 46 (51.1%) knees were in male patients, and the mean body mass index was 30.4 kg/m2 (21 to 36). The same cruciate retaining total knee system was used in both groups. All patients received an uncemented femoral component and no patients had their patella resurfaced. Patient outcomes were assessed preoperatively and postoperatively using the modified Oxford Knee Score, Knee Society Score, and 12-Item Short-Form Health Survey questionnaire (SF-12) score. Radiographs were analyzed using the American Knee Society Radiograph Evaluation score. Operative complications, reoperations, or revision surgery were recorded. A total of 90 knees were randomized and at last review 77 knees were assessed. In all, 11 patients had died and two were lost to follow-up.Aims
Methods
This study aims to evaluate a new home medical stretching device called the Self Treatment Assisted Knee (STAK) tool to treat knee arthrofibrosis. 35 patients post-major knee surgery with arthrofibrosis and mean range of movement (ROM) of 68° were recruited. Both the STAK intervention and control group received standard physiotherapy for eight weeks, with the intervention group additionally using the STAK at home. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford Knee Scores (OKS) were collected at all timepoints. An acceptability and home exercise questionnaire capturing adherence was recorded after each of the interventions.Aims
Methods
Proliferation, migration, and differentiation of anterior cruciate ligament (ACL) remnant and surrounding cells are fundamental processes for ACL reconstruction; however, the interaction between ACL remnant and surrounding cells is unclear. We hypothesized that ACL remnant cells preserve the capability to regulate the surrounding cells’ activity, collagen gene expression, and tenogenic differentiation. Moreover, extracorporeal shock wave (ESW) would not only promote activity of ACL remnant cells, but also enhance their paracrine regulation of surrounding cells. Cell viability, proliferation, migration, and expression levels of Collagen-I (COL-I) A1, transforming growth factor beta (TGF-β), and vascular endothelial growth factor (VEGF) were compared between ACL remnant cells untreated and treated with ESW (0.15 mJ/mm2, 1,000 impulses, 4 Hz). To evaluate the subsequent effects on the surrounding cells, bone marrow stromal cells (BMSCs)’ viability, proliferation, migration, and levels of Type I Collagen, Type III Collagen, and tenogenic gene (Aims
Methods
Our objective is to describe our early and mid-term results with the use of a new simple primary knee prosthesis as an articulating spacer in planned two-stage management for infected knee arthroplasty. As a second objective, we compared outcomes between the group with a retained first stage and those with a complete two-stage revision. We included 47 patients (48 knees) with positive criteria for infection, with a minimum two-year follow-up, in which a two-stage approach with an articulating spacer with new implants was used. Patients with infection control, and a stable and functional knee were allowed to retain the initial first-stage components. Outcomes recorded included: infection control rate, reoperations, final range of motion (ROM), and quality of life assessment (QoL) including Western Ontario and McMaster Universities osteoarthritis index, Knee Injury and Osteoarthritis Outcome Score, Oxford Knee Score, 12-Item Short-Form Health Survey questionnaire, and University of California Los Angeles (UCLA) activity score and satisfaction score. These outcomes were evaluated and compared to additional cohorts of patients with retained first-stage interventions and those with a complete two-stage revision. Mean follow-up was 3.7 years (2.0 to 6.5).Aims
Methods
A significant percentage of patients remain dissatisfied after total knee arthroplasty (TKA). The aim of this study was to determine whether the sequential addition of accelerometer-based navigation for femoral component preparation and sensor-guided ligament balancing improved complication rates, radiological alignment, or patient-reported outcomes (PROMs) compared with a historical control group using conventional instrumentation. This retrospective cohort study included 371 TKAs performed by a single surgeon sequentially. A historical control group, with the use of intramedullary guides for distal femoral resection and surgeon-guided ligament balancing, was compared with a group using accelerometer-based navigation for distal femoral resection and surgeon-guided balancing (group 1), and one using navigated femoral resection and sensor-guided balancing (group 2). Primary outcome measures were Patient-Reported Outcomes Measurement Information System (PROMIS) and Knee injury and Osteoarthritis Outcome (KOOS) scores measured preoperatively and at six weeks and 12 months postoperatively. The position of the components and the mechanical axis of the limb were measured postoperatively. The postoperative range of motion (ROM), haematocrit change, and complications were also recorded.Aims
Methods
The aims of this study were to determine the effect of osteophyte excision on deformity correction and soft tissue gap balance in varus knees undergoing computer-assisted total knee arthroplasty (TKA). A total of 492 consecutive, cemented, cruciate-substituting TKAs performed for varus osteoarthritis were studied. After exposure and excision of both cruciates and menisci, it was noted from operative records the corrective interventions performed in each case. Knees in which no releases after the initial exposure, those which had only osteophyte excision, and those in which further interventions were performed were identified. From recorded navigation data, coronal and sagittal limb alignment, knee flexion range, and medial and lateral gap distances in maximum knee extension and 90° knee flexion with maximal varus and valgus stresses, were established, initially after exposure and excision of both cruciate ligaments, and then also at trialling. Knees were defined as ‘aligned’ if the hip-knee-ankle axis was between 177° and 180°, (0° to 3° varus) and ‘balanced’ if medial and lateral gaps in extension and at 90° flexion were within 2 mm of each other.Aims
Methods
Robotic-assisted total knee arthroplasty (RA-TKA) has been introduced to provide accurate bone cuts and help achieve the target knee alignment, along with symmetric gap balancing. The purpose of this study was to determine if any early clinical benefits could be realized following TKA using robotic-assisted technology. In all, 140 consecutive patients undergoing RA-TKA and 127 consecutive patients undergoing conventional TKA with minimum six-week follow-up were reviewed. Differences in visual analogue scores (VAS) for pain at rest and with activity, postoperative opiate usage, and length of stay (LOS) between the RA-TKA and conventional TKA groups were compared.Aims
Methods
The objectives of this study were to assess the effect of anterior cruciate ligament (ACL) resection on flexion-extension gaps, mediolateral soft tissue laxity, maximum knee extension, and limb alignment during primary total knee arthroplasty (TKA). This prospective study included 140 patients with symptomatic knee osteoarthritis undergoing primary robotic-arm assisted TKA. All operative procedures were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess study outcomes pre- and post-ACL resection with knee extension and 90° knee flexion. This study included 76 males (54.3%) and 64 females (45.7%) with a mean age of 64.1 years (SD 6.8) at time of surgery. Mean preoperative hip-knee-ankle deformity was 6.1° varus (SD 4.6° varus).Aims
Methods
To compare patients undergoing total knee arthroplasty (TKA) with ≤ 80° range of movement (ROM) operated with a 2 mm increase in the flexion gap with matched non-stiff patients with at least 100° of preoperative ROM and balanced flexion and extension gaps. In a retrospective cohort study, 98 TKAs (91 patients) with a preoperative ROM of ≤ 80° were examined. Mean follow-up time was 53 months (24 to 112). All TKAs in stiff knees were performed with a 2 mm increased flexion gap. Data were compared to a matched control group of 98 TKAs (86 patients) with a mean follow-up of 43 months (24 to 89). Knees in the control group had a preoperative ROM of at least 100° and balanced flexion and extension gaps. In all stiff and non-stiff knees posterior stabilized (PS) TKAs with patellar resurfacing in combination with adequate soft tissue balancing were used.Aims
Methods
The aim is to assess the cost-effectiveness of patellofemoral arthroplasty (PFA) in comparison with total knee arthroplasty (TKA) for the treatment of isolated patellofemoral osteoarthritis (OA) based on prospectively collected data on health outcomes and resource use from a blinded, randomized, clinical trial. A total of 100 patients with isolated patellofemoral osteoarthritis were randomized to receive either PFA or TKA by experienced knee surgeons trained in using both implants. Patients completed patient-reported outcomes including EuroQol five-dimension questionnaire (EQ-5D) and 6-Item Short-Form Health Survey questionnaire (SF-6D) before the procedure. The scores were completed again after six weeks, three, six, and nine months, and again after one- and two-year post-surgery and yearly henceforth. Time-weighted outcome measures were constructed. Cost data were obtained from clinical registrations and patient-reported questionnaires. Incremental gain in health outcomes (quality-adjusted life-years (QALYs)) and incremental costs were compared for the two groups of patients. Net monetary benefit was calculated assuming a threshold value of €10,000, €35,000, and €50,000 per QALY and used to test the statistical uncertainty and central assumptions about outcomes and costs.Aims
Methods
The primary stability of the cementless Oxford Unicompartmental Knee Replacement (OUKR) relies on interference fit (or press fit). Insufficient interference may cause implant loosening, whilst excessive interference could cause bone damage and fracture. The aim of this study was to identify the optimal interference fit by measuring the force required to seat the tibial component of the cementless OUKR (push-in force) and the force required to remove the component (pull-out force). Six cementless OUKR tibial components were implanted in 12 new slots prepared on blocks of solid polyurethane foam (20 pounds per cubic foot (PCF), Sawbones, Malmo, Sweden) with a range of interference of 0.1 mm to 1.9 mm using a Dartec materials testing machine HC10 (Zwick Ltd, Herefordshire, United Kingdom) . The experiment was repeated with cellular polyurethane foam (15 PCF), which is a more porous analogue for trabecular bone.Objectives
Materials and Methods
To compare the gait of unicompartmental knee arthroplasty (UKA)
and total knee arthroplasty (TKA) patients with healthy controls,
using a machine-learning approach. 145 participants (121 healthy controls, 12 patients with cruciate-retaining
TKA, and 12 with mobile-bearing medial UKA) were recruited. The
TKA and UKA patients were a minimum of 12 months post-operative,
and matched for pattern and severity of arthrosis, age, and body
mass index. Participants walked on an instrumented treadmill until their
maximum walking speed was reached. Temporospatial gait parameters,
and vertical ground reaction force data, were captured at each speed.
Oxford knee scores (OKS) were also collected. An ensemble of trees
algorithm was used to analyse the data: 27 gait variables were used
to train classification trees for each speed, with a binary output
prediction of whether these variables were derived from a UKA or
TKA patient. Healthy control gait data was then tested by the decision
trees at each speed and a final classification (UKA or TKA) reached
for each subject in a majority voting manner over all gait cycles
and speeds. Top walking speed was also recorded.Aims
Patients and Methods
The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis was evaluated using the joint space width and Kellgren-Lawrence (KL) radiographic classification. The Objectives
Methods
Risk of revision following total knee arthroplasty (TKA) is higher
in patients under 55 years, but little data are reported regarding
non-revision outcomes. This study aims to identify predictors of
dissatisfaction in these patients. We prospectively assessed 177 TKAs (157 consecutive patients,
99 women, mean age 50 years; 17 to 54) from 2008 to 2013. Age, gender,
implant, indication, body mass index (BMI), social deprivation,
range of movement, Kellgren-Lawrence (KL) grade of osteoarthritis
(OA) and prior knee surgery were recorded. Pre- and post-operative
Oxford Knee Score (OKS) as well as Short Form-12 physical (PCS)
and mental component scores were obtained. Post-operative range
of movement, complications and satisfaction were measured at one
year.Aims
Patients and Methods
The purpose of this study was to develop an accurate, reliable and easily applicable method for determining the anatomical location of the joint line during revision knee arthroplasty. The transepicondylar width (TEW), the perpendicular distance between the medial and lateral epicondyles and the distal articular surfaces (DMAD, DLAD) and the distance between the medial and lateral epicondyles and the posterior articular surfaces (PMAD, DLAD) were measured in 40 knees from 20 formalin-fixed adult cadavers (11 male and nine female; mean age at death 56.9 years, Objectives
Methods
The objective of this study was to validate the
efficacy of Takeuchi classification for lateral hinge fractures
(LHFs) in open wedge high tibial osteotomy (OWHTO). In all 74 osteoarthritic
knees (58 females, 16 males; mean age 62.9 years, standard deviation
7.5, 42 to 77) were treated with OWHTO using a TomoFix plate. The
knees were divided into non-fracture (59 knees) and LHF (15 knees)
groups, and the LHF group was further divided into Takeuchi types
I, II, and III (seven, two, and six knees, respectively). The outcomes
were assessed pre-operatively and one year after OWHTO. Pre-operative
characteristics (age, gender and body mass index) showed no significant
difference between the two groups. The mean Japanese Orthopaedic
Association score was significantly improved one year after operation
regardless of the presence or absence of LHF (p = 0.0015, p <
0.001, respectively). However, six of seven type I cases had no
LHF-related complications; both type II cases had delayed union;
and of six type III cases, two had delayed union with correction
loss and one had overcorrection. These results suggest that Takeuchi
type II and III LHFs are structurally unstable compared with type
I. Cite this article:
The treatment of osteochondral lesions is of
great interest to orthopaedic surgeons because most lesions do not heal
spontaneously. We present the short-term clinical outcome and MRI
findings of a cell-free scaffold used for the treatment of these
lesions in the knee. A total of 38 patients were prospectively evaluated
clinically for two years following treatment with an osteochondral
nanostructured biomimetic scaffold. There were 23 men and 15 women; the
mean age of the patients was 30.5 years (15 to 64). Clinical outcome
was assessed using the Knee Injury and Osteoarthritis Outcome Score
(KOOS), the Tegner activity scale and a Visual Analgue scale for
pain. MRI data were analysed based on the Magnetic Resonance Observation
of Cartilage Repair Tissue (MOCART) scoring system at three, 12
and 24 months post-operatively. There was a continuous significant
clinical improvement after surgery. In two patients, the scaffold
treatment failed (5.3%) There was a statistically significant improvement
in the MOCART precentage scores. The repair tissue filled most of
the defect sufficiently. We found subchondral laminar changes in all
patients. Intralesional osteophytes were found in two patients (5.3%).
We conclude that this one-step scaffold-based technique can be used
for osteochondral repair. The surgical technique is straightforward,
and the clinical results are promising. The MRI aspects of the repair
tissue continue to evolve during the first two years after surgery.
However, the subchondral laminar and bone changes are a concern. Cite this article:
We report the outcome of 32 patients (37 knees) who underwent hemicallostasis with a dynamic external fixator for osteoarthritis of the medial compartment of the knee. There were 16 men (19 knees) and 16 women (18 knees) with a mean age at operation of 54.6 years (27 to 72). The aim was to achieve a valgus overcorrection of 2° to 8° or mechanical axis at 62.5% (± 12.5%). At a mean follow-up of 62.8 months (51 to 81) there was no change in the mean range of movement, and no statistically significant difference in the Insall-Salvati index or tibial slope (p = 0.11 and p = 0.15, respectively). The mean hip-knee-ankle angle changed from 190.6 (183° to 197°) to 176.0° (171° to 181°), with a mean final position of the mechanical axis of 58.5% (35.1% to 71.2%). The desired alignment was attained in 31 of 37 (84%) knees. There were 21 excellent, 13 good, two fair and one poor result according to the Oxford knee score with no correlation between age and final score. This score was at its best at one year with a statistically significant deterioration at two years (p = 0.001) followed by a small but not statistically significant deterioration until the final follow-up (p = 0.17). All the knees with Ahlback grade 1 osteoarthritis had excellent or good results. Complications included pin tract infections involving 16.4% of all pins used, delayed union in two, knee stiffness in four, fracture of the lateral cortex in one and ring sequestrum in one. In conclusion, hemicallostasis provides precision in attaining the desired alignment without interfering with tibial slope or patellar height, and is relatively free of serious complications.
We conducted a randomised prospective study to evaluate the clinical and radiological results of a mobile- and fixed-bearing total knee replacement of similar design in 174 patients who had bilateral simultaneous knee replacement. The mean follow-up was for 5.6 years (5.2 to 6.1). The total knee score, pain score, functional score and range of movement were not statistically different (p >
0.05) between the two groups. Osteolysis was not seen in any knee in either group. Two knees (1%) in the mobile-bearing group required revision because of infection; none in the fixed-bearing group needed revision. Excellent results can be achieved with both mobile- and fixed-bearing prostheses of similar design at mid-term follow-up. We could demonstrate no significant clinical advantage for a mobile bearing.
Progressive degenerative changes in the medial
compartment of the knee following lateral unicompartmental arthroplasty
(UKA) remains a leading indication for revision surgery. The purpose
of this study is to evaluate changes in the congruence and joint
space width (JSW) of the medial compartment following lateral UKA.
The congruence of the medial compartment of 53 knees (24 men, 23
women, mean age 13.1 years; Our data suggest that a well conducted lateral UKA may improve
the congruence and normalise the JSW of the medial compartment,
potentially preventing progression of degenerative change. Cite this article:
Peri-prosthetic infection is amongst the most
common causes of failure following total knee replacement (TKR).
In the presence of established infection, thorough joint debridement
and removal of all components is necessary following which new components
may be implanted. This can be performed in one or two stages; two-stage revision
with placement of an interim antibiotic-loaded spacer is regarded
by many to be the standard procedure for eradication of peri-prosthetic
joint infection. We present our experience of a consecutive series of 50 single-stage
revision TKRs for established deep infection performed between 1979
and 2010. There were 33 women and 17 men with a mean age at revision
of 66.8 years (42 to 84) and a mean follow-up of 10.5 years (2 to
24). The mean time between the primary TKR and the revision procedure
was 2.05 years (1 to 8). Only one patient required a further revision for recurrent infection,
representing a success rate of 98%. Nine patients required further
revision for aseptic loosening, according to microbiological testing
of biopsies taken at the subsequent surgery. Three other patients
developed a further septic episode but none required another revision. These results suggest that a single-stage revision can produce
comparable results to a two-stage revision. Single-stage revision
offers a reduction in costs as well as less morbidity and inconvenience
for patients. Cite this article:
We report the long-term outcome of 33 patients
(37 knees) who underwent proximal tibial open-wedge osteotomy with
hemicallotasis (HCO) for medial osteoarthritis of the knee between
1995 and 2000. Among these, 29 patients with unilateral HCO were
enrolled and 19 were available for review at a mean of 14.2 years
(10 to 15.7) post-operatively. For these 19 patients, the mean Hospital
for Special Surgery knee score was 60 (57 to 62) pre-operatively
and 85 (82 to 87) at final follow-up (p <
0.001; paired Cite this article:
Oxidised zirconium was introduced as a material for femoral components
in total knee arthroplasty (TKA) as an attempt to reduce polyethylene
wear. However, the long-term survival of this component is not known. We performed a retrospective review of a prospectively collected
database to assess the ten year survival and clinical and radiological
outcomes of an oxidised zirconium total knee arthroplasty with the
Genesis II prosthesis. The Western Ontario and McMaster Universities Osteoarthritis
Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS)
and a patient satisfaction scale were used to assess outcome.Aims
Methods
We explored the outcome of staged bilateral total
knee replacement (TKR) for symmetrical degenerative joint disease
and deformity in terms of patient expectations, functional outcome
and satisfaction. From 2009 to 2011, 70 consecutive patients (41
female) with a mean age of 71.7 years (43 to 89) underwent 140 staged
bilateral TKRs at our institution, with a mean time between operations
of 7.8 months (2 to 25). Patients were assessed pre-operatively
and at six and 12 months post-operatively using the Short Form-12,
Oxford knee score (OKS), expectation questionnaire and satisfaction
score. The pre-operative OKS was significantly worse before the
first TKR (TKR1), but displayed significantly greater improvement
than that observed after the second TKR (TKR2). Expectation level
increased from TKR1 to TKR2 in 17% and decreased in 20%. Expectations
of pain relief and stair-climbing were less before TKR2; in contrast,
expectations of sporting and social activities were greater. Decreased expectations
of TKR2 were significantly associated with younger age and high
expectations before TKR1. Patient satisfaction was high for both
TKR1 (93%) and TKR2 (87%) but did not correlate significantly within
individuals. We concluded that satisfaction with one TKR does not
necessarily translate to satisfaction following the second. Cite this article:
Bone mineral density (BMD) around the femoral component has been reported to decrease after total knee replacement (TKR) because of stress shielding. Our aim was to determine whether a cemented mobile-bearing component reduced the post-operative loss of BMD. In our study 28 knees receiving a cemented fixed-bearing TKR were matched with 28 receiving a cemented mobile-bearing TKR. They underwent dual-energy x-ray absorptiometry, pre-operatively and at three weeks and at three, six, 12, 18 and 24 months post-operatively. The patients were not taking medication to improve the BMD. The pre-operative differences in the BMD of the femoral neck, wrist, lumbar spine and knee in the two groups were not significant. The BMD of the femur decreased postoperatively in the fixed-bearing group, but not the mobile-bearing group. The difference in the post-operative change in the BMD in the two groups was statistically significant (p <
0.05) at 18 and 24 months. Our findings show that a cemented mobile-bearing TKR has a favourable effect on the BMD of the distal femur after TKR in the short term. Further study is required to determine the long-term effects.
This study validates the short-form WOMAC function scale for assessment of conservative treatment of osteoarthritis of the knee. Data were collected before treatment and six and nine months later, from 100 patients with osteoarthritis of the knee to determine the validity, internal consistency, test-retest reliability, floor and ceiling effects, and responsiveness of the short-form WOMAC function scale. The scale showed high correlation with the traditional WOMAC and other measures. The internal consistency was good (Cronbach α: 0.88 to 0.95) and an excellent test-retest reliability was found (Lin’s concordance correlation coefficient (ρc): 0.85 to 0.94). The responsiveness was adequate and comparable to that of the traditional WOMAC (standardised response mean 0.56 to 0.44 and effect size 0.64 to 0.57) and appeared not to be significantly affected by floor or ceiling effects (0% and 7%, respectively). The short-form WOMAC function scale is a valid, reliable and responsive alternative to the traditional WOMAC in the evaluation of patients with osteoarthritis of the knee managed conservatively. It is simple to use in daily practice and is therefore less of a burden for patients in clinical trials.
We undertook a study in which 138 female patients with a mean age of 71.2 years (51 to 82) received a standard NexGen CR-flex prosthesis in one knee and a gender-specific NexGen CR-flex prosthesis in the other. The mean follow-up period was 3.25 years (3.1 to 3.5). The aspect ratios of the standard and gender-specific prostheses were compared with that of the distal femur. The mean post-operative Knee Society knee scores were 94 (70 to 100) and 93 (70 to 100) points and the function scores were 83 (60 to 100) and 84 (60 to 100) points for the standard implants and the gender-specific designs, respectively. The mean post-operative Western Ontario and McMaster Universities score was 26.4 points (0 to 76). Patient satisfaction, the radiological results and the complication rates were similar in the two groups. In those with a standard prosthesis, the femoral component was closely matched in 80 knees (58.0%), overhung in 14 (10.1%) and undercovered the bone in 44 (31.9%). In those with a gender-specific prosthesis, it was closely matched in 15 knees (10.9%) and undercovered the bone in 123 (89.1%). Since we found no significant differences between the two groups with regard to the clinical and radiological results, patient satisfaction or complication rate, the goal of the design of the gender-specific CR-flex prosthesis to improve the outcome was not achieved in our patients.
