Aims. We have previously reported the mid-term outcomes of revision total knee arthroplasty (TKA) for
Modifications in the design of knee replacements have been proposed in order to maximise
Aims. Surgeons commonly resect additional distal femur during primary total knee arthroplasty (TKA) to correct a
Aims. To compare patients undergoing total knee arthroplasty (TKA) with ≤ 80° range of movement (ROM) operated with a 2 mm increase in the
Aims. Patients with
Aims. This study aimed to evaluate the association between the sagittal alignment of the femoral component in total knee arthroplasty (TKA) and new Knee Society Score (2011KSS), under the hypothesis that outliers such as the excessive extended or
Fixed
Aims. 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). Methods. 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. Results. The ISR gradually decreased over five years after TKA, and finally 33 patients (20.0%) had patella baja. Patella baja at the final follow-up was not related to passive knee ROM or KSS. Interestingly, when we divided into two groups - patella baja and patella normal-alta (ISR ≥ 0.8) - the patella baja group already had a lower patellar height before surgery, compared with the patella normal-alta group. The ISR measurement error in this study was 0.17. Both passive knee
Aims. Mid-level constraint designs for total knee arthroplasty (TKA) are intended to reduce coronal plane laxity. Our aims were to compare kinematics and ligament forces of the Zimmer Biomet Persona posterior-stabilized (PS) and mid-level designs in the coronal, sagittal, and axial planes under loads simulating clinical exams of the knee in a cadaver model. Methods. We performed TKA on eight cadaveric knees and loaded them using a robotic manipulator. We tested both PS and mid-level designs under loads simulating clinical exams via applied varus and valgus moments, internal-external (IE) rotation moments, and anteroposterior forces at 0°, 30°, and 90° of
Aims. The aim of this study was to compare a bicruciate-retaining (BCR) total knee arthroplasty (TKA) with a posterior cruciate-retaining (CR) TKA design in terms of kinematics, measured using fluoroscopy and stability as micromotion using radiostereometric analysis (RSA). Methods. A total of 40 patients with end-stage osteoarthritis were included in this randomized controlled trial. All patients performed a step-up and lunge task in front of a monoplane fluoroscope one year postoperatively. Femorotibial contact point (CP) locations were determined at every
Aims. We aimed to assess the reliability and validity of OpenPose, a posture estimation algorithm, for measurement of knee range of motion after total knee arthroplasty (TKA), in comparison to radiography and goniometry. Methods. In this prospective observational study, we analyzed 35 primary TKAs (24 patients) for knee osteoarthritis. We measured the knee angles in
Aims. It is unknown whether gap laxities measured in robotic arm-assisted total knee arthroplasty (TKA) correlate to load sensor measurements. The aim of this study was to determine whether symmetry of the maximum medial and lateral gaps in extension and
Aims. Tibial tubercle osteotomy (TTO) facilitates surgical exposure and protects the extensor mechanism during revision total knee arthroplasty (rTKA). The purpose of this study was to determine the rates of bony union, complications, and reoperations following TTO during rTKA, to assess the functional outcomes of rTKA with TTO at two years’ minimum follow-up, and to identify the risk factors of failure. Methods. Between January 2010 and September 2020, 695 rTKAs were performed and data were entered into a prospective database. Inclusion criteria were rTKAs with concomitant TTO, without extensor mechanism allograft, and a minimum of two years’ follow-up. A total of 135 rTKAs were included, with a mean age of 65 years (SD 9.0) and a mean BMI of 29.8 kg/m. 2. (SD 5.7). The most frequent indications for revision were infection (50%; 68/135), aseptic loosening (25%; 34/135), and stiffness (13%; 18/135). Patients had standardized follow-up at six weeks, three months, six months, and annually thereafter. Complications and revisions were evaluated at the last follow-up. Functional outcomes were assessed using the Knee Society Score (KSS) and range of motion. Results. The mean follow-up was 51 months (SD 26; 24 to 121). Bony union was confirmed in 95% of patients (128/135) at a mean of 3.4 months (SD 2.7). The complication rate was 15% (20/135), consisting of nine tibial tubercle fracture displacements (6.7%), seven nonunions (5%), two delayed unions, one tibial fracture, and one wound dehiscence. Seven patients (5%) required eight revision procedures (6%): three bone grafts, three osteosyntheses, one extensor mechanism allograft, and one wound revision. The functional scores and
This study aimed to determine the correlation between the amount of maximum
Aims. The aims of this study were to investigate the ability to kneel after total knee arthroplasty (TKA) without patellar resurfacing, and its effect on patient-reported outcome measures (PROMs). Secondary aims included identifying which kneeling positions were most important to patients, and the influence of radiological parameters on the ability to kneel before and after TKA. Methods. This prospective longitudinal study involved 209 patients who underwent single radius cruciate-retaining TKA without patellar resurfacing. Preoperative EuroQol five-dimension questionnaire (EQ-5D), Oxford Knee Score (OKS), and the ability to achieve four kneeling positions were assessed including a single leg kneel, a double leg kneel, a high-flexion kneel, and a praying position. The severity of radiological osteoarthritis (OA) was graded and the pattern of OA was recorded intraoperatively. The
Aims. This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS). Methods. Patients scheduled for primary TKA were included in a single-centre, prospective, three-armed, blinded randomized trial (n = 216; 72 per group). After intraoperative confirmation of posterior cruciate ligament (PCL) integrity, patients were randomly allocated to receive a CR, AS, or PS design from the same TKA system. Insertion of an AS or PS design required PCL resection. The primary outcome was the mean score of all five subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS) at two-year follow-up. Secondary outcomes included all KOOS subscales, Oxford Knee Score, EuroQol five-dimension health questionnaire, EuroQol visual analogue scale, range of motion (ROM), and willingness to undergo the operation again. Patient satisfaction was also assessed. Results. Patients reported similar levels of pain, function, satisfaction, and general health regardless of the prosthetic design they received. Mean maximal
Aims. The aims of this study were: 1) to describe extended restricted kinematic alignment (E-rKA), a novel alignment strategy during robotic-assisted total knee arthroplasty (RA-TKA); 2) to compare residual medial compartment tightness following virtual surgical planning during RA-TKA using mechanical alignment (MA) and E-rKA, in the same set of osteoarthritic varus knees; 3) to assess the requirement of soft-tissue releases during RA-TKA using E-rKA; and 4) to compare the accuracy of surgical plan execution between knees managed with adjustments in component positioning alone, and those which require additional soft-tissue releases. Methods. Patients who underwent RA-TKA between January and December 2022 for primary varus osteoarthritis were included. Safe boundaries for E-rKA were defined. Residual medial compartment tightness was compared following virtual surgical planning using E-rKA and MA, in the same set of knees. Soft-tissue releases were documented. Errors in postoperative alignment in relation to planned alignment were compared between patients who did (group A) and did not (group B) require soft-tissue releases. Results. The use of E-rKA helped restore all knees within the predefined boundaries, with appropriate soft-tissue balancing. E-rKA compared with MA resulted in reduced residual medial tightness following surgical planning, in full extension (2.71 mm (SD 1.66) vs 5.16 mm (SD 3.10), respectively; p < 0.001), and 90° of
Varus and valgus joint laxity of the normal living knee in
Between June 1993 and December 1994, we performed total knee arthroplasty (TKA) on 27 knees in 24 patients with spontaneous bony ankylosis in severe
This prospective randomised controlled double-blind
trial compared two types of PFC Sigma total knee replacement (TKR),
differing in three design features aimed at improving
Aims. One of the main causes of tibial revision surgery for total knee arthroplasty is aseptic loosening. Therefore, stable fixation between the tibial component and the cement, and between the tibial component and the bone, is essential. A factor that could influence the implant stability is the implant design, with its different variations. In an existing implant system, the tibial component was modified by adding cement pockets. The aim of this experimental in vitro study was to investigate whether additional cement pockets on the underside of the tibial component could improve implant stability. The relative motion between implant and bone, the maximum pull-out force, the tibial cement mantle, and a possible path from the bone marrow to the metal-cement interface were determined. Methods. A tibial component with (group S: Attune S+) and without (group A: Attune) additional cement pockets was implanted in 15 fresh-frozen human leg pairs. The relative motion was determined under dynamic loading (extension-flexion 20° to 50°, load-level 1,200 to 2,100 N) with subsequent determination of the maximum pull-out force. In addition, the cement mantle was analyzed radiologically for possible defects, the tibia base cement adhesion, and preoperative bone mineral density (BMD). Results. The BMD showed no statistically significant difference between both groups. Group A showed for all load levels significantly higher maximum relative motion compared to group S for 20° and 50°
The shape of the
We investigated fixed
The optimal management of the tibial slope in
achieving a high
Our purpose was to determine the mechanism which allows the maximum knee
Total knee replacement and high tibial osteotomy are common orthopaedic operations with low complication rates. Such surgery is in close proximity to the popliteal artery (PA), the behaviour of which during
We have studied the concept of posterior condylar offset and the importance of its restoration on the maximum range of knee
Patient dissatisfaction is not uncommon following primary total knee arthroplasty. One proposed method to alleviate this is by improving knee kinematics. Therefore, we aimed to answer the following research question: are there significant differences in knee kinematics based on the design of the tibial insert (cruciate-retaining (CR), ultra-congruent (UC), or medial congruent (MC))? Overall, 15 cadaveric knee joints were examined with a CR implant with three different tibial inserts (CR, UC, and MC) using an established knee joint simulator. The effects on coronal alignment, medial and lateral femoral roll back, femorotibial rotation, bony rotations (femur, tibia, and patella), and patellofemoral length ratios were determined.Aims
Methods
The term mid-flexion instability has entered
the orthopaedic literature as a concept, but has not been confirmed
as a distinct clinical entity. The term is used freely, sometimes
as a synonym for
Aims. The aim of this study was to compare any differences in the primary outcome (biphasic
Aims. Modern total knee arthroplasty (TKA) prostheses are designed to restore near normal kinematics including high
Limb alignment in total knee arthroplasty (TKA) influences periarticular soft-tissue tension, biomechanics through knee
Aims. Total knee arthroplasty (TKA) using functional alignment aims to implant the components with minimal compromise of the soft-tissue envelope by restoring the plane and obliquity of the non-arthritic joint. The objective of this study was to determine the effect of TKA with functional alignment on mediolateral soft-tissue balance as assessed using intraoperative sensor-guided technology. Methods. This prospective study included 30 consecutive patients undergoing robotic-assisted TKA using the Stryker PS Triathlon implant with functional alignment. Intraoperative soft-tissue balance was assessed using sensor-guided technology after definitive component implantation; soft-tissue balance was defined as intercompartmental pressure difference (ICPD) of < 15 psi. Medial and lateral compartment pressures were recorded at 10°, 45°, and 90° of knee
Aims. The impact of a diaphyseal femoral deformity on knee alignment varies according to its severity and localization. The aims of this study were to determine a method of assessing the impact of diaphyseal femoral deformities on knee alignment for the varus knee, and to evaluate the reliability and the reproducibility of this method in a large cohort of osteoarthritic patients. Methods. All patients who underwent a knee arthroplasty from 2019 to 2021 were included. Exclusion criteria were genu valgus,
Aims. Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs. Methods. A retrospective review of our total joint registry identified 94 patients with post-polio syndrome undergoing 116 primary TKAs between January 2000 and December 2019. The mean age was 70 years (33 to 86) with 56% males (n = 65) and a mean BMI of 31 kg/m. 2. (18 to 49). Rotating hinge TKAs were used in 14 of 63 affected limbs (22%), but not in any of the 53 unaffected limbs. Kaplan-Meier survivorship analyses were completed. The mean follow-up was eight years (2 to 19). Results. The ten-year survivorship free from revision was 91% (95% confidence interval (CI) 81 to 100) in affected and 84% (95% CI 68 to 100) in unaffected limbs. There were six revisions in affected limbs: three for periprosthetic femoral fractures and one each for periprosthetic joint infection (PJI), patellar clunk syndrome, and instability. Unaffected limbs were revised in four cases: two for instability and one each for PJI and tibial component loosening. The ten-year survivorship free from any reoperation was 86% (95% CI 75 to 97) and 80% (95% CI 64 to 99) in affected and unaffected limbs, respectively. There were three additional reoperations among affected and two in unaffected limbs. There were 12 nonoperative complications, including four periprosthetic fractures. Arthrofibrosis occurred in five affected (8%) and two unaffected limbs (4%). Postoperative range of motion decreased with 31% achieving less than 90° knee
Aims. Single-shot adductor canal block (ACB) after total knee arthroplasty (TKA) for postoperative analgesia is a common modality. Patients can experience breakthrough pain when the effect of ACB wears off. Local anaesthetic infusion through an intra-articular catheter (IAC) can help manage breakthrough pain after TKA. We hypothesized that combined ACB with ropivacaine infusion through IAC is associated with better pain relief compared to ACB used alone. Methods. This study was a prospective double-blinded placebo-controlled randomized controlled trial to compare the efficacy of combined ACB+ IAC-ropivacaine infusion (study group, n = 68) versus single-shot ACB+ intra-articular normal saline placebo (control group, n = 66) after primary TKA. The primary outcome was assessment of pain, using the visual analogue scale (VAS) recorded at 6, 12, 24, and 48 hours after surgery. Secondary outcomes included active knee ROM 48 hours after surgery and additional requirement of analgesia for breakthrough pain. Results. The study group (mean visual analogue scale (VAS) pain score of 5.5 (SD 0.889)) experienced significant reduction in pain 12 hours after surgery compared to the control group (mean VAS 6.62 (SD 1.356); mean difference = 1.12, 95% confidence interval (CI) -1.46 to 0.67; p < 0.001), and pain scores on postoperative day (POD) 1 and POD-2 were lower in the study group compared to the control group (mean difference in VAS pain = 1.04 (-1.39 to -0.68, 95% CI, p < 0.001). Fewer patients in the study group (0 vs 3 in the control group) required additional analgesia for breakthrough pain, but this was not statistically significant. The study group had significantly increased active knee
Aims. Unicompartmental knee arthroplasty (UKA) has become a popular method of treating knee localized osteoarthritis (OA). Additionally, the posterior cruciate ligament (PCL) is essential to maintaining the physiological kinematics and functions of the knee joint. Considering these factors, the purpose of this study was to investigate the biomechanical effects on PCL-deficient knees in medial UKA. Methods. Computational simulations of five subject-specific models were performed for intact and PCL-deficient UKA with tibial slopes. Anteroposterior (AP) kinematics and contact stresses of the patellofemoral (PF) joint and the articular cartilage were evaluated under the deep-knee-bend condition. Results. As compared to intact UKA, there was no significant difference in AP translation in PCL-deficient UKA with a low
Aims. 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). Methods. 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
Aims. Neither a surgeon’s intraoperative impression nor the parameters of computer navigation have been shown to be predictive of the outcomes following total knee arthroplasty (TKA). The aim of this study was to determine whether a surgeon, with robotic assistance, can predict the outcome as assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain (KPS), one year postoperatively, and establish what factors correlate with poor KOOS scores in a well-aligned and balanced TKA. Methods. A total of 134 consecutive patients who underwent TKA using a dynamic ligament tensioning robotic system with a tibia first resection technique and a cruciate sacrificing ultracongruent TKA system were enrolled into a prospective study. Each TKA was graded based on the final mediolateral ligament balance at 10° and 90° of
Aims. The aim of this study was to assess the effect of posterior cruciate ligament (PCL) resection on flexion-extension gaps, mediolateral soft-tissue laxity, fixed
Aims. 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). Methods. 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
Aims. The results of kinematic total knee arthroplasty (KTKA) have been reported in terms of limb and component alignment parameters but not in terms of gap laxities and differentials. In kinematic alignment (KA), balance should reflect the asymmetrical balance of the normal knee, not the classic rectangular
Aims. Manipulation under anaesthesia (MUA) remains an effective intervention to address restricted range of motion (ROM) after total knee arthroplasty (TKA) and occurs in 2% to 3% of primary TKAs at our institution. Since there are few data on the outcomes of MUA with different anaesthetic methods, we sought to compare the outcomes of patients undergoing MUA with intravenous (IV) sedation and neuraxial anaesthesia. Methods. We identified 548 MUAs after primary TKA (136 IV sedation, 412 neuraxial anaesthesia plus IV sedation) from March 2016 to July 2019. The mean age of this cohort was 62 years (35 to 88) with a mean body mass index of 31 kg/m. 2. (18 to 49). The mean time from primary TKA to MUA was 10.2 weeks (6.2 to 24.3). Pre-MUA ROM was similar between groups; overall mean pre-MUA extension was 4.2° (p = 0.452) and mean pre-MUA
Aims. The removal of the cruciate ligaments in total knee arthroplasty (TKA) has been suggested as a potential contributing factor to patient dissatisfaction, due to alteration of the in vivo biomechanics of the knee. Bicruciate retaining (BCR) TKA allows the preservation of the cruciate ligaments, thus offering the potential to reproduce healthy kinematics. The aim of this study was to compare in vivo kinematics between the operated and contralateral knee in patients who have undergone TKA with a contemporary BCR design. Methods. A total of 29 patients who underwent unilateral BCR TKA were evaluated during single-leg deep lunges and sit-to-stand tests using a validated computer tomography and fluoroscopic imaging system. In vivo six-degrees of freedom (6DOF) kinematics were compared between the BCR TKA and the contralateral knee. Results. During single-leg deep lunge, BCR TKAs showed significantly less mean posterior femoral translation (13 mm; standard deviation (SD) 4) during terminal
Aims. Patellofemoral problems are a common complication of total knee arthroplasty. A high compressive force across the patellofemoral joint may affect patient-reported outcome. However, the relationship between patient-reported outcome and the intraoperative patellofemoral contact force has not been investigated. The purpose of this study was to determine whether or not a high intraoperative patellofemoral compressive force affects patient-reported outcome. Patients and Methods. This prospective study included 42 patients (42 knees) with varus-type osteoarthritis who underwent a bi-cruciate stabilized total knee arthroplasty and in whom the planned alignment was confirmed on 3D CT. Of the 42 patients, 36 were women and six were men. Their mean age was 72.3 years (61 to 87) and their mean body mass index (BMI) was 24.4 kg/m2 (18.2 to 34.3). After implantation of the femoral and tibial components, the compressive force across the patellofemoral joint was measured at 10°, 30°, 60°, 90°, 120°, and 140° of
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. Methods. 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). Results. Overall, 90-day mean
Aims. 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). Methods. 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/m. 2. (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
Aims. A comprehensive classification for coronal lower limb alignment with predictive capabilities for knee balance would be beneficial in total knee arthroplasty (TKA). This paper describes the Coronal Plane Alignment of the Knee (CPAK) classification and examines its utility in preoperative soft tissue balance prediction, comparing kinematic alignment (KA) to mechanical alignment (MA). Methods. A radiological analysis of 500 healthy and 500 osteoarthritic (OA) knees was used to assess the applicability of the CPAK classification. CPAK comprises nine phenotypes based on the arithmetic HKA (aHKA) that estimates constitutional limb alignment and joint line obliquity (JLO). Intraoperative balance was compared within each phenotype in a cohort of 138 computer-assisted TKAs randomized to KA or MA. Primary outcomes included descriptive analyses of healthy and OA groups per CPAK type, and comparison of balance at 10° of
Aims. The aim of this study was to determine and compare the congruency of the articular surface contact area of the patellofemoral joint (PFJ) during both active and passive movement of the knee with the use of an MRI mapping technique in both the stable and unstable PFJ. Patients and Methods. A prospective case-control MRI imaging study of patients with a history of PFJ instability and a control group of volunteers without knee symptoms was performed. The PFJs were imaged with the use of an MRI scan during both passive and active movement from 0° through to 40° of
Aims. It is unknown whether kinematic alignment (KA) objectively improves knee balance in total knee arthroplasty (TKA), despite this being the biomechanical rationale for its use. This study aimed to determine whether restoring the constitutional alignment using a restrictive KA protocol resulted in better quantitative knee balance than mechanical alignment (MA). Methods. We conducted a randomized superiority trial comparing patients undergoing TKA assigned to KA within a restrictive safe zone or MA. Optimal knee balance was defined as an intercompartmental pressure difference (ICPD) of 15 psi or less using a pressure sensor. The primary endpoint was the mean intraoperative ICPD at 10° of
This study aimed to evaluate if total knee arthroplasty (TKA) femoral components aligned in either mechanical alignment (MA) or kinematic alignment (KA) are more biomimetic concerning trochlear sulcus orientation and restoration of trochlear height. Bone surfaces from 1,012 CT scans of non-arthritic femora were segmented using a modelling and analytics system. TKA femoral components (Triathlon; Stryker) were virtually implanted in both MA and KA. Trochlear sulcus orientation was assessed by measuring the distal trochlear sulcus angle (DTSA) in native femora and in KA and MA prosthetic femoral components. Trochlear anatomy restoration was evaluated by measuring the differences in medial, lateral, and sulcus trochlear height between native femora and KA and MA prosthetic femoral components.Aims
Methods
Aims. 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. Methods. 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. Results. Tibial base plate rotation was significantly more variable in the SL group with 75% of tibiae mal-rotated. Multivariate analysis of navigation data found no difference based on all kinematic parameters across the range of motion (ROM). However, area under the curve analysis showed that knees placed in the HL position had much smaller differences between the pre- and post-surgery conditions for kinematics mean values across the entire ROM. Conclusion. The sagittal tibia cut, not dependent on standard instrumentation, determines the tibial component rotation. The HL position improves accuracy of this step compared to the SL position, probably due to better visuospatial orientation of the hip and knee to the surgeon. The HL position is better for replicating native kinematics of the knee as shown by the area under the curve analysis. In the supine knee position, care must be taken during the sagittal tibia cut, while checking
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
Total knee arthroplasty (TKA) with a highly congruent condylar-stabilized (CS) articulation may be advantageous due to increased stability versus cruciate-retaining (CR) designs, while mitigating the limitations of a posterior-stabilized construct. The aim was to assess ten-year implant survival and functional outcomes of a cemented single-radius TKA with a CS insert, performed without posterior cruciate ligament sacrifice. This retrospective cohort study included consecutive patients undergoing TKA at a specialist centre in the UK between November 2010 and December 2012. Data were collected using a bespoke electronic database and cross-referenced with national arthroplasty audit data, with variables including: preoperative characteristics, intraoperative factors, complications, and mortality status. Patient-reported outcome measures (PROMs) were collected by a specialist research team at ten years post-surgery. There were 536 TKAs, of which 308/536 (57.5%) were in female patients. The mean age was 69.0 years (95% CI 45.0 to 88.0), the mean BMI was 32.2 kg/m2 (95% CI 18.9 to 50.2), and 387/536 (72.2%) survived to ten years. There were four revisions (0.7%): two deep infections (requiring debridement and implant retention), one aseptic loosening, and one haemosiderosis.Aims
Methods
As has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA). Experimental knees were immobilized for either four weeks (72 mice) or eight weeks (72 mice), followed by a remobilization period of zero weeks (24 mice), two weeks (24 mice), or four weeks (24 mice) after suture removal. Half of the experimental knees also received an intra-articular injury. Biomechanical data were collected to measure passive extension angle (PEA). Histological data measuring area and thickness of posterior and anterior knee capsules were collected from knee sections.Aims
Methods
A fracture of the medial tibial plateau is a serious complication of Oxford mobile-bearing unicompartmental knee arthroplasty (OUKA). The risk of these fractures is reportedly lower when using components with a longer keel-cortex distance (KCDs). The aim of this study was to examine how slight varus placement of the tibial component might affect the KCDs, and the rate of tibial plateau fracture, in a clinical setting. This retrospective study included 255 patients who underwent 305 OUKAs with cementless tibial components. There were 52 males and 203 females. Their mean age was 73.1 years (47 to 91), and the mean follow-up was 1.9 years (1.0 to 2.0). In 217 knees in 187 patients in the conventional group, tibial cuts were made orthogonally to the tibial axis. The varus group included 88 knees in 68 patients, and tibial cuts were made slightly varus using a new osteotomy guide. Anterior and posterior KCDs and the origins of fracture lines were assessed using 3D CT scans one week postoperatively. The KCDs and rate of fracture were compared between the two groups.Aims
Methods
The goal was to evaluate tibiofemoral knee joint kinematics during stair descent, by simulating the full stair descent motion in vitro. The knee joint kinematics were evaluated for two types of knee implants: bi-cruciate retaining and bi-cruciate stabilized. It was hypothesized that the bi-cruciate retaining implant better approximates native kinematics. The in vitro study included 20 specimens which were tested during a full stair descent with physiological muscle forces in a dynamic knee rig. Laxity envelopes were measured by applying external loading conditions in varus/valgus and internal/external direction.Aims
Methods
The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous.Aims
Methods
The use of high tibial osteotomy (HTO) to delay total knee arthroplasty (TKA) in young patients with osteoarthritis (OA) and constitutional deformity remains debated. The aim of this study was to compare the long-term outcomes of TKA after HTO compared to TKA without HTO, using the time from the index OA surgery as reference (HTO for the study group, TKA for the control group). This was a case-control study of consecutive patients receiving a posterior-stabilized TKA for OA between 1996 and 2010 with previous HTO. A total of 73 TKAs after HTO with minimum ten years’ follow-up were included. Cases were matched with a TKA without previous HTO for age at the time of the HTO. All revisions were recorded. Kaplan-Meier survivorship analysis was performed using revision of metal component as the endpoint. The Knee Society Score, range of motion, and patient satisfaction were assessed.Aims
Methods
This systematic review and meta-analysis aimed to compare the influence of patellar resurfacing following cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) on the incidence of anterior knee pain, knee-specific patient-reported outcome measures, complication rates, and reoperation rates. A systematic review of MEDLINE, PubMed, and Google Scholar was performed to identify randomized controlled trials (RCTs) according to search criteria. Search terms used included: arthroplasty, replacement, knee (Mesh), TKA, prosthesis, patella, patellar resurfacing, and patellar retaining. RCTs that compared patellar resurfacing versus unresurfaced in primary TKA were included for further analysis. Studies were evaluated using the Scottish Intercollegiate Guidelines Network assessment tool for quality and minimization of bias. Data were synthesized and meta-analysis performed.Aims
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The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous.Aims
Methods
A functional anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) has been assumed to be required for patients undergoing unicompartmental knee arthroplasty (UKA). However, this assumption has not been thoroughly tested. Therefore, this study aimed to assess the biomechanical effects exerted by cruciate ligament-deficient knees with medial UKAs regarding different posterior tibial slopes. ACL- or PCL-deficient models with posterior tibial slopes of 1°, 3°, 5°, 7°, and 9° were developed and compared to intact models. The kinematics and contact stresses on the tibiofemoral joint were evaluated under gait cycle loading conditions.Aims
Methods
Micromotion of the polyethylene (PE) inlay may contribute to backside PE wear in addition to articulate wear of total knee arthroplasty (TKA). Using radiostereometric analysis (RSA) with tantalum beads in the PE inlay, we evaluated PE micromotion and its relationship to PE wear. A total of 23 patients with a mean age of 83 years (77 to 91), were available from a RSA study on cemented TKA with Maxim tibial components (Zimmer Biomet). PE inlay migration, PE wear, tibial component migration, and the anatomical knee axis were evaluated on weightbearing stereoradiographs. PE inlay wear was measured as the deepest penetration of the femoral component into the PE inlay.Aims
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The tibial component of total knee arthroplasty can either be an all-polyethylene (AP) implant or a metal-backed (MB) implant. This study aims to compare the five-year functional outcomes of AP tibial components to MB components in patients aged over 70 years. Secondary aims are to compare quality of life, implant survivorship, and cost-effectiveness. A group of 130 patients who had received an AP tibial component were matched for demographic factors of age, BMI, American Society of Anesthesiologists (ASA) grade, sex, and preoperative Knee Society Score (KSS) to create a comparison group of 130 patients who received a MB tibial component. Functional outcome was assessed prospectively by KSS, quality of life by 12-Item Short-Form Health Survey questionnaire (SF-12), and range of motion (ROM), and implant survivorships were compared. The SF six-dimension (6D) was used to calculate the incremental cost effectiveness ratio (ICER) for AP compared to MB tibial components using quality-adjusted life year methodology.Aims
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To map literature on prognostic factors related to outcomes of revision total knee arthroplasty (rTKA), to identify extensively studied factors and to guide future research into what domains need further exploration. We performed a systematic literature search in MEDLINE, Embase, and Web of Science. The search string included multiple synonyms of the following keywords: "revision TKA", "outcome" and "prognostic factor". We searched for studies assessing the association between at least one prognostic factor and at least one outcome measure after rTKA surgery. Data on sample size, study design, prognostic factors, outcomes, and the direction of the association was extracted and included in an evidence map.Aims
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To assess the incidence of radiological lateral osteoarthritis (OA) at 15 years after medial unicompartmental knee arthroplasty (UKA) and assess the relationship of lateral OA with symptoms and patient characteristics. Cemented Phase 3 medial Oxford UKA implanted by two surgeons since 1998 for the recommended indications were prospectively followed. A 15-year cumulative revision rate for lateral OA of 5% for this series was previously reported. A total of 163 unrevised knees with 15-year (SD 1) anterior-posterior knee radiographs were studied. Lateral joint space width (JSWL) was measured and severity of lateral OA was classified as: nil/mild, moderate, and severe. Preoperative and 15-year Oxford Knee Scores (OKS) and American Knee Society Scores were determined. The effect of age, sex, BMI, and intraoperative findings was analyzed. Statistical analysis included one-way analysis of variance and Kruskal-Wallis H test, with significance set at 5%.Aims
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Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively.Aims
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The primary aim was to assess whether robotic total knee arthroplasty (rTKA) had a greater early knee-specific outcome when compared to manual TKA (mTKA). Secondary aims were to assess whether rTKA was associated with improved expectation fulfilment, health-related quality of life (HRQoL), and patient satisfaction when compared to mTKA. A randomized controlled trial was undertaken, and patients were randomized to either mTKA or rTKA. The primary objective was functional improvement at six months. Overall, 100 patients were randomized, 50 to each group, of whom 46 rTKA and 41 mTKA patients were available for review at six months following surgery. There were no differences between the two groups.Aims
Methods
Aims. Aseptic loosening of the tibial component is a frequent cause of failure in primary total knee arthroplasty (TKA). Management options include an isolated tibial revision or full component revision. A full component revision is frequently selected by surgeons unfamiliar with the existing implant or who simply wish to “start again”. This option adds morbidity compared with an isolated tibial revision. While isolated tibial revision has a lower morbidity, it is technically more challenging due to difficulties with exposure and maintaining prosthetic stability. This study was designed to compare these two reconstructive options. Methods. Patients undergoing revision TKA for isolated aseptic tibial loosening between 2012 and 2017 were identified. Those with revision implants or revised for infection, instability, osteolysis, or femoral component loosening were excluded. A total of 164 patients were included; 88 had an isolated tibial revision and 76 had revision of both components despite only having a loose tibial component. The demographics and clinical and radiological outcomes were recorded. Results. The patient demographics were statistically similar in the two cohorts. The median follow-up was 3.5 years (interquartile range (IQR) 1 to 12.5). Supplementary femoral metaphyseal fixation was required in five patients in the full revision cohort. There was a higher incidence of radiological tibial loosening in the full component revision cohort at the final follow-up (8 (10.5%) vs 5 (5.7%); p = 0.269). Three patients in the full component revision cohort developed instability while only one in the isolated tibial cohort did. Three patients in the full revision cohort developed a
The aim of this study was to evaluate medium- to long-term outcomes and complications of the Stanmore Modular Individualised Lower Extremity System (SMILES) rotating hinge implant in revision total knee arthroplasty (rTKA) at a tertiary unit. It is hypothesized that this fully cemented construct leads to satisfactory clinical outcomes. A retrospective consecutive study of all patients who underwent a rTKA using the fully cemented SMILES rotating hinge prosthesis between 2005 to 2018. Outcome measures included aseptic loosening, reoperations, revision for any cause, complications, and survivorship. Patients and implant survivorship data were identified through both prospectively collected local hospital electronic databases and linked data from the National Joint Registry/NHS Personal Demographic Service. Kaplan-Meier survival analysis was used at ten years.Aims
Methods
The aim of this study was to compare the migration of the femoral component, five years postoperatively, between patients with a highly cross-linked polyethylene (HXLPE) insert and those with a conventional polyethylene (PE) insert in an uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary aims included clinical outcomes and patient-reported outcome measures (PROMs). We have previously reported the migration and outcome of the tibial components in these patients. A double-blinded randomized controlled trial was conducted including 96 TKAs. The migration of the femoral component was measured with radiostereometry (RSA) at three and six months and one, two, and five years postoperatively. PROMs were collected preoperatively and at all periods of follow-up.Aims
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Aseptic loosening is the most common cause of failure following cemented total knee arthroplasty (TKA), and has been linked to poor cementation technique. We aimed to develop a consensus on the optimal technique for component cementation in TKA. A UK-based, three-round, online modified Delphi Expert Consensus Study was completed focusing on cementation technique in TKA. Experts were identified as having a minimum of five years’ consultant experience in the NHS and fulfilling any one of the following criteria: a ‘high volume’ knee arthroplasty practice (> 150 TKAs per annum) as identified from the National joint Registry of England, Wales, Northern Ireland and the Isle of Man; a senior author of at least five peer reviewed articles related to TKA in the previous five years; a surgeon who is named trainer for a post-certificate of comletion of training fellowship in TKA.Aims
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The rate of day-case total knee arthroplasty (TKA) in the UK is currently approximately 0.5%. Reducing length of stay allows orthopaedic providers to improve efficiency, increase operative throughput, and tackle the rising demand for joint arthroplasty surgery and the COVID-19-related backlog. Here, we report safe delivery of day-case TKA in an NHS trust via inpatient wards with no additional resources. Day-case TKAs, defined as patients discharged on the same calendar day as surgery, were retrospectively reviewed with a minimum follow-up of six months. Analysis of hospital and primary care records was performed to determine readmission and reattendance rates. Telephone interviews were conducted to determine patient satisfaction.Aims
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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
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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
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The mid-term results of kinematic alignment (KA) for total knee arthroplasty (TKA) using image derived instrumentation (IDI) have not been reported in detail, and questions remain regarding ligamentous stability and revisions. This paper aims to address the following: 1) what is the distribution of alignment of KA TKAs using IDI; 2) is a TKA alignment category associated with increased risk of failure or poor patient outcomes; 3) does extending limb alignment lead to changes in soft-tissue laxity; and 4) what is the five-year survivorship and outcomes of KA TKA using IDI? A prospective, multicentre, trial enrolled 100 patients undergoing KA TKA using IDI, with follow-up to five years. Alignment measures were conducted pre- and postoperatively to assess constitutional alignment and final implant position. Patient-reported outcome measures (PROMs) of pain and function were also included. The Australian Orthopaedic Association National Joint Arthroplasty Registry was used to assess survivorship.Aims
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Conflicting clinical results are reported for the ATTUNE Total Knee Arthroplasty (TKA). This randomized controlled trial (RCT) evaluated five-year follow-up results comparing cemented ATTUNE and PFC-Sigma cruciate retaining TKAs, analyzing component migration as measured by radiostereometric analysis (RSA), clinical outcomes, patient-reported outcome measures (PROMs), and radiological outcomes. A total of 74 primary TKAs were included in this single-blind RCT. RSA examinations were performed, and PROMs and clinical outcomes were collected immediate postoperatively, and at three, six, 12, 24, and 60 months’ follow-up. Radiolucent lines (RLLs) were measured in standard anteroposterior radiographs at six weeks, and 12 and 60 months postoperatively.Aims
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Aims. There are comparatively few randomized studies evaluating knee arthroplasty prostheses, and fewer still that report longer-term functional outcomes. The aim of this study was to evaluate mid-term outcomes of an existing implant trial cohort to document changing patient function over time following total knee arthroplasty using longitudinal analytical techniques and to determine whether implant design chosen at time of surgery influenced these outcomes. Methods. A mid-term follow-up of the remaining 125 patients from a randomized cohort of total knee arthroplasty patients (initially comprising 212 recruited patients), comparing modern (Triathlon) and traditional (Kinemax) prostheses was undertaken. Functional outcomes were assessed with the Oxford Knee Score (OKS), knee range of movement, pain numerical rating scales, lower limb power output, timed functional assessment battery, and satisfaction survey. Data were linked to earlier assessment timepoints, and analyzed by repeated measures analysis of variance (ANOVA) mixed models, incorporating longitudinal change over all assessment timepoints. Results. The mean follow-up of the 125 patients was 8.12 years (7.3 to 9.4). There was a reduction in all assessment parameters relative to earlier assessments. Longitudinal models highlight changes over time in all parameters and demonstrate large effect sizes. Significant between-group differences were seen in measures of knee
Implantation of ultra-purified alginate (UPAL) gel is safe and effective in animal osteochondral defect models. This study aimed to examine the applicability of UPAL gel implantation to acellular therapy in humans with cartilage injury. A total of 12 patients (12 knees) with symptomatic, post-traumatic, full-thickness cartilage lesions (1.0 to 4.0 cm2) were included in this study. UPAL gel was implanted into chondral defects after performing bone marrow stimulation technique, and assessed for up to three years postoperatively. The primary outcomes were the feasibility and safety of the procedure. The secondary outcomes were self-assessed clinical scores, arthroscopic scores, tissue biopsies, and MRI-based estimations.Aims
Methods
To evaluate whether low-intensity pulsed ultrasound (LIPUS) accelerates bone healing at osteotomy sites and promotes functional recovery after open-wedge high tibial osteotomy (OWHTO). Overall, 90 patients who underwent OWHTO without bone grafting were enrolled in this nonrandomized retrospective study, and 45 patients treated with LIPUS were compared with 45 patients without LIPUS treatment in terms of bone healing and functional recovery postoperatively. Clinical evaluations, including the pain visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score, were performed preoperatively as well as six weeks and three, six, and 12 months postoperatively. The progression rate of gap filling was evaluated using anteroposterior radiographs at six weeks and three, six, and 12 months postoperatively.Aims
Methods
The aim of this study was to evaluate the cost-effectiveness of arthroscopic partial meniscectomy versus physical therapy plus optional delayed arthroscopic partial meniscectomy in young patients aged under 45 years with traumatic meniscal tears. We conducted a multicentre, open-labelled, randomized controlled trial in patients aged 18 to 45 years, with a recent onset, traumatic, MRI-verified, isolated meniscal tear without knee osteoarthritis. Patients were randomized to arthroscopic partial meniscectomy or standardized physical therapy with an optional delayed arthroscopic partial meniscectomy after three months of follow-up. We performed a cost-utility analysis on the randomization groups to compare both treatments over a 24-month follow-up period. Cost utility was calculated as incremental costs per quality-adjusted life year (QALY) gained of arthroscopic partial meniscectomy compared to physical therapy. Calculations were performed from a healthcare system perspective and a societal perspective.Aims
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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
With up to 40% of patients having patellofemoral joint osteoarthritis (PFJ OA), the two arthroplasty options are to replace solely the patellofemoral joint via patellofemoral arthroplasty (PFA), or the entire knee via total knee arthroplasty (TKA). The aim of this study was to assess postoperative success of second-generation PFAs compared to TKAs for patients treated for PFJ OA using patient-reported outcome measures (PROMs) and domains deemed important by patients following a patient and public involvement meeting. MEDLINE, EMBASE via OVID, CINAHL, and EBSCO were searched from inception to January 2022. Any study addressing surgical treatment of primary patellofemoral joint OA using second generation PFA and TKA in patients aged above 18 years with follow-up data of 30 days were included. Studies relating to OA secondary to trauma were excluded. ROB-2 and ROBINS-I bias tools were used.Aims
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The aim of this study was to evaluate the association between chondral injury and interval from anterior cruciate ligament (ACL) tear to surgical reconstruction (ACLr). Between January 2012 and January 2022, 1,840 consecutive ACLrs were performed and included in a single-centre retrospective cohort. Exclusion criteria were partial tears, multiligament knee injuries, prior ipsilateral knee surgery, concomitant unicompartmental knee arthroplasty or high tibial osteotomy, ACL agenesis, and unknown date of tear. A total of 1,317 patients were included in the final analysis, with a median age of 29 years (interquartile range (IQR) 23 to 38). The median preoperative Tegner Activity Score (TAS) was 6 (IQR 6 to 7). Patients were categorized into four groups according to the delay to ACLr: < three months (427; 32%), three to six months (388; 29%), > six to 12 months (248; 19%), and > 12 months (254; 19%). Chondral injury was assessed during arthroscopy using the International Cartilage Regeneration and Joint Preservation Society classification, and its association with delay to ACLr was analyzed using multivariable analysis.Aims
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The aim of this study was to report patient and clinical outcomes following robotic-assisted total knee arthroplasty (RA-TKA) at multiple institutions with a minimum two-year follow-up. This was a multicentre registry study from October 2016 to June 2021 that included 861 primary RA-TKA patients who completed at least one pre- and postoperative patient-reported outcome measure (PROM) questionnaire, including Forgotten Joint Score (FJS), Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement (KOOS JR), and pain out of 100 points. The mean age was 67 years (35 to 86), 452 were male (53%), mean BMI was 31.5 kg/m2 (19 to 58), and 553 (64%) cemented and 308 (36%) cementless implants.Aims
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Intraoperative pressure sensors allow surgeons to quantify soft-tissue balance during total knee arthroplasty (TKA). The aim of this study was to determine whether using sensors to achieve soft-tissue balance was more effective than manual balancing in improving outcomes in TKA. A multicentre randomized trial compared the outcomes of sensor balancing (SB) with manual balancing (MB) in 250 patients (285 TKAs). The primary outcome measure was the mean difference in the four Knee injury and Osteoarthritis Outcome Score subscales (ΔKOOS4) in the two groups, comparing the preoperative and two-year scores. Secondary outcomes included intraoperative balance data, additional patient-reported outcome measures (PROMs), and functional measures.Aims
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The antidiabetic agent metformin inhibits fibrosis in various organs. This study aims to elucidate the effects of hyperglycaemia and metformin on knee joint capsule fibrosis in mice. Eight-week-old wild-type (WT) and type 2 diabetic (db/db) mice were divided into four groups without or with metformin treatment (WT met(-/+), Db met(-/+)). Mice received daily intraperitoneal administration of metformin and were killed at 12 and 14 weeks of age. Fibrosis morphology and its related genes and proteins were evaluated. Fibroblasts were extracted from the capsules of 14-week-old mice, and the expression of fibrosis-related genes in response to glucose and metformin was evaluated in vitro.Aims
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While mechanical alignment (MA) is the traditional technique in total knee arthroplasty (TKA), its potential for altering constitutional alignment remains poorly understood. This study aimed to quantify unintentional changes to constitutional coronal alignment and joint line obliquity (JLO) resulting from MA. A retrospective cohort study was undertaken of 700 primary MA TKAs (643 patients) performed between 2014 and 2017. Lateral distal femoral and medial proximal tibial angles were measured pre- and postoperatively to calculate the arithmetic hip-knee-ankle angle (aHKA), JLO, and Coronal Plane Alignment of the Knee (CPAK) phenotypes. The primary outcome was the magnitude and direction of aHKA, JLO, and CPAK alterations.Aims
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The primary objective of this registry-based study was to compare patient-reported outcomes of cementless and cemented medial unicompartmental knee arthroplasty (UKA) during the first postoperative year. The secondary objective was to assess one- and three-year implant survival of both fixation techniques. We analyzed 10,862 cementless and 7,917 cemented UKA cases enrolled in the Dutch Arthroplasty Registry, operated between 2017 and 2021. Pre- to postoperative change in outcomes at six and 12 months’ follow-up were compared using mixed model analyses. Kaplan-Meier and Cox regression models were applied to quantify differences in implant survival. Adjustments were made for patient-specific variables and annual hospital volume.Aims
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The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs). All patients with PDFF primarily treated with DP, SP, or DFA between 2008 and 2022 at a university teaching hospital were included in this retrospective cohort study. The primary outcome was revision surgery for failure following DP, SP, or DFA. Secondary outcome measures included any reoperation, length of hospital stay, and mortality. All basic demographic and relevant implant and injury details were collected. Radiological analysis included fracture classification and evaluation of metaphyseal and medial comminution.Aims
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The aim was to assess whether robotic-assisted total knee arthroplasty (rTKA) had greater knee-specific outcomes, improved fulfilment of expectations, health-related quality of life (HRQoL), and patient satisfaction when compared with manual TKA (mTKA). A randomized controlled trial was undertaken (May 2019 to December 2021), and patients were allocated to either mTKA or rTKA. A total of 100 patients were randomized, 50 to each group, of whom 43 rTKA and 38 mTKA patients were available for review at 12 months following surgery. There were no statistically significant preoperative differences between the groups. The minimal clinically important difference in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score was defined as 7.5 points.Aims
Methods
Objectives. Throughout the 20th Century, it has been postulated that the knee moves on the basis of a four-bar link mechanism composed of the cruciate ligaments, the femur and the tibia. As a consequence, the femur has been thought to roll back with
The kinematic alignment (KA) approach to total knee arthroplasty (TKA) has recently increased in popularity. Accordingly, a number of derivatives have arisen and have caused confusion. Clarification is therefore needed for a better understanding of KA-TKA. Calipered (or true, pure) KA is performed by cutting the bone parallel to the articular surface, compensating for cartilage wear. In soft-tissue respecting KA
Aim. There has been a significant reduction in unicompartmental knee arthroplasty (UKA) procedures recorded in Australia. This follows several national joint registry studies documenting high UKA revision rates when compared to total knee arthroplasty (TKA). With the recent introduction of robotically assisted UKA procedures, it is hoped that outcomes improve. This study examines the cumulative revision rate of UKA procedures implanted with a newly introduced robotic system and compares the results to one of the best performing non-robotically assisted UKA prostheses, as well as all other non-robotically assisted UKA procedures. Methods. Data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR) for all UKA procedures performed for osteoarthritis (OA) between 2015 and 2018 were analyzed. Procedures using the Restoris MCK UKA prosthesis implanted using the Mako Robotic-Arm Assisted System were compared to non-robotically assisted Zimmer Unicompartmental High
The purpose of this study was to compare the clinical outcomes, mortalities, implant survival rates, and complications of total knee arthroplasty (TKA) in patients with or without hepatitis B virus (HBV) infection over at least ten years of follow-up. From January 2008 to December 2010, 266 TKAs were performed in 169 patients with HBV (HBV group). A total of 169 propensity score–matched patients without HBV were chosen for the control group in a one-to-one ratio. Then, the clinical outcomes, mortalities, implant survival rates, and complications of TKA in the two groups were compared. The mean follow-up periods were 11.7 years (10.5 to 13.4) in the HBV group and 11.8 years (11.5 to 12.4) in the control group.Aims
Methods
Instability in
Aims. In Asia and the Middle-East, people often
No predictive model has been published to forecast operating time for total knee arthroplasty (TKA). The aims of this study were to design and validate a predictive model to estimate operating time for robotic-assisted TKA based on demographic data, and evaluate the added predictive power of CT scan-based predictors and their impact on the accuracy of the predictive model. A retrospective study was conducted on 1,061 TKAs performed from January 2016 to December 2019 with an image-based robotic-assisted system. Demographic data included age, sex, height, and weight. The femoral and tibial mechanical axis and the osteophyte volume were calculated from CT scans. These inputs were used to develop a predictive model aimed to predict operating time based on demographic data only, and demographic and 3D patient anatomy data.Aims
Methods
The outcome of total knee replacement (TKR) using
components designed to increase the range of
The aim of this study was to evaluate medium-term outcomes and complications of the S-ROM NOILES Rotating Hinge Knee System (DePuy, USA) in revision total knee arthroplasty (rTKA) at a tertiary unit. A retrospective consecutive study of all patients who underwent a rTKA using this implant from January 2005 to December 2018. Outcome measures included reoperations, revision for any cause, complications, and survivorship. Patients and implant survivorship data were identified through both local hospital electronic databases and linked data from the National Joint Registry/NHS Personal Demographic Service. Kaplan-Meier survival analysis was used at ten years.Aims
Methods