Metal particles detached from metal-on-metal hip prostheses (MoM-THA) have been shown to cause inflammation and destruction of tissues. To further explore this, we investigated the histopathology (aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL) score) and metal concentrations of the periprosthetic tissues obtained from patients who underwent revision knee arthroplasty. We also aimed to investigate whether accumulated metal debris was associated with ALVAL-type reactions in the synovium. Periprosthetic metal concentrations in the synovia and histopathological samples were analyzed from 230 patients from our institution from October 2016 to December 2019. An ordinal regression model was calculated to investigate the effect of the accumulated metals on the histopathological reaction of the synovia.Aims
Methods
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). 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.Aims
Methods
Objectives. There remains a lack of data on the reliability of methods to
estimate tibial coverage achieved during total knee replacement.
In order to address this gap, the intra- and interobserver reliability
of a three-dimensional (3D) digital templating method was assessed
with one symmetric and one asymmetric
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. 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).Aims
Methods
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. 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.Aims
Methods
Modern total knee arthroplasty (TKA) prostheses are designed to restore near normal kinematics including high flexion. Kneeling is a high flexion, kinematically demanding activity after TKA. The debate about design choice has not yet been informed by six-degrees-of-freedom in vivo kinematics. This prospective randomized clinical trial compared kneeling kinematics in three TKA designs. In total, 68 patients were randomized to either a posterior stabilized (PS-FB), cruciate-retaining (CR-FB), or rotating platform (CR-RP) design. Of these patients, 64 completed a minimum one year follow-up. Patients completed full-flexion kneeling while being imaged using single-plane fluoroscopy. Kinematics were calculated by registering the 3D implant models onto 2D-dynamic fluoroscopic images and exported for analysis.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
Enhanced perioperative protocols have significantly improved patient recovery following primary total knee arthroplasty (TKA). Little has been investigated the effectiveness of these protocols for revision TKA (RTKA). We report on a matched group of aseptic revision and primary TKA patients treated with an identical pain and rehabilitation programmes. Overall, 40 aseptic full-component RTKA patients were matched (surgical date, age, sex, and body mass index (BMI)) to a group of primary cemented TKA patients. All RTKAs had new uncemented stemmed femoral and tibial components with metaphyseal sleeves. Both groups were treated with an identical postoperative pain protocol. Patients were followed for at least two years. Knee Society Scores (KSS) at six weeks and at final follow-up were recorded for both groups.Aims
Methods
Aims
Patients and Methods
The medially spherical GMK Sphere (Medacta International AG, Castel San Pietro, Switzerland) total knee arthroplasty (TKA) was previously shown to accommodate lateral rollback while pivoting around a stable medial compartment, aiming to replicate native knee kinematics in which some coronal laxity, especially laterally, is also present. We assess coronal plane kinematics of the GMK Sphere and explore the occurrence and pattern of articular separation during static and dynamic activities. Using pulsed fluoroscopy and image matching, the coronal kinematics and articular surface separation of 16 well-functioning TKAs were studied during weight-bearing and non-weight-bearing, static, and dynamic activities. The closest distances between the modelled articular surfaces were examined with respect to knee position, and proportions of joint poses exhibiting separation were computed.Objectives
Methods
As the population ages, there is projected to be an increase in the level of demand for total knee arthroplasty (TKA) in octogenarians. We aimed to explore whether those aged ≥ 80 years achieved similar improvements in physical function to younger patients while also comparing the rates of length of stay (LOS), discharge to rehabilitation, postoperative complications, and mortality following TKA in older and younger patients. Patients from one institution who underwent primary elective TKA between 1 January 2006 and 31 December 2014 were dichotomized into those ≥ 80 years old (n = 359) and those < 80 years old (n = 2479) for comparison. Multivariable regression was used to compare the physical status component of the 12-Item Short-Form Health Survey (SF-12), LOS, discharge to rehabilitation, complications, and mortality between the two groups.Aims
Patients and Methods
Posterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect of PCO and PTS on cruciate retaining TKA. We generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions.Objectives
Methods
The aim of this to study was to compare the previously unreported
long-term survival outcome of the Oxford medial unicompartmental
knee arthroplasty (UKA) performed by trainee surgeons and consultants. We therefore identified a previously unreported cohort of 1084
knees in 947 patients who had a UKA inserted for anteromedial knee
arthritis by consultants and surgeons in training, at a tertiary
arthroplasty centre and performed survival analysis on the group
with revision as the endpoint.Aims
Patients and Methods
The purpose of this study was to investigate
whether a gender-specific high-flexion posterior-stabilised (PS)
total knee replacement (TKR) would offer advantages over a high-flex
PS TKR regarding range of movement (ROM), ‘feel’ of the knee, pain
and satisfaction, as well as during activity. A total of 24 female
patients with bilateral osteoarthritis entered this prospective,
blind randomised trial in which they received a high-flex PS TKR
in one knee and a gender-specific high-flexion PS TKR in the other
knee. At follow-up, patients were assessed clinically measuring
ROM, and questioned about pain, satisfaction and daily ‘feel’ of
each knee. Patients underwent gait analysis pre-operatively and
at one year, which yielded kinematic, kinetic and temporospatial
parameters indicative of knee function during gait. At final follow-up
we found no statistically significant differences in ROM (p = 0.82).
The median pain score was 0 (0 to 8) in both groups (p = 0.95).
The median satisfaction score was 9 (4 to 10) in the high-flex group
and 8 (0 to 10) in the gender-specific group (p = 0.98). The median
‘feel’ score was 9 (3 to 10) in the high-flex group and 8 (0 to
10) in the gender-specific group (p = 0.66). Gait analysis showed
no statistically significant differences between the two prosthetic
designs in any kinematic, kinetic or temporospatial parameters. Both designs produced good clinical results with
Numerous complications following total knee replacement (TKR)
relate to the patellofemoral (PF) joint, including pain and patellar
maltracking, yet the options for A total of three knees with end-stage osteoarthritis and three
knees that had undergone TKR at more than one year’s follow-up were
investigated. In each knee, sequential biplane radiological images
were acquired from the sagittal direction (i.e. horizontal X-ray
source and 10° below horizontal) for a sequence of eight flexion
angles. Three-dimensional implant or bone models were matched to
the biplane images to compute the six degrees of freedom of PF tracking
and TF kinematics, and other clinical measures.Objectives
Methods
We compared the results of 146 patients who received an anatomic modular knee fixed-bearing total knee replacement (TKR) in one knee and a low contact stress rotating platform mobile-bearing TKR in the other. There were 138 women and eight men with a mean age of 69.8 years (42 to 80). The mean follow-up was 13.2 years (11.0 to 14.5). The patients were assessed clinically and radiologically using the rating systems of the Hospital for Special Surgery and the Knee Society at three months, six months, one year, and annually thereafter. The assessment scores of both rating systems pre-operatively and at the final review did not show any statistically significant differences between the two designs of implant. In the anatomic modular knee group, one knee was revised because of aseptic loosening of the tibial component and one because of infection. In addition, three knees were revised because of wear of the polyethylene tibial bearing. In the low contact stress group, two knees were revised because of instability requiring exchange of the polyethylene insert and one because of infection. The radiological analysis found no statistical difference in the incidence of radiolucent lines at the final review (Student’s We found no evidence of the superiority of one design over the other at long-term follow-up.
