Cementless knee arthroplasty has seen a recent resurgence in popularity due to conceptual advantages, including improved osseointegration providing biological fixation, increased surgical efficiency, and reduced systemic complications associated with cement impaction and wear from cement debris. Increasingly younger and higher demand patients are requiring knee arthroplasty, and as such, there is optimism cementless fixation may improve implant survivorship and functional outcomes. Compared to cemented implants, the National Joint Registry (NJR) currently reports higher revision rates in cementless total knee arthroplasty (TKA), but lower in unicompartmental knee arthroplasty (UKA). However, recent studies are beginning to show excellent outcomes with cementless implants, particularly with UKA which has shown superior performance to cemented varieties. Cementless TKA has yet to show long-term benefit, and currently performs equivalently to cemented in short- to medium-term cohort studies. However, with novel concepts including 3D-printed coatings, robotic-assisted surgery, radiostereometric analysis, and kinematic or functional knee alignment principles, it is hoped they may help improve the outcomes of cementless TKA in the long-term. In addition, though cementless implant costs remain higher due to novel implant coatings, it is speculated cost-effectiveness can be achieved through greater surgical efficiency and potential reduction in revision costs. There is paucity of level one data on long-term outcomes between fixation methods and the cost-effectiveness of modern cementless knee arthroplasty. This review explores recent literature on cementless knee arthroplasty, with regards to clinical outcomes, implant survivorship, complications, and cost-effectiveness; providing a concise update to assist clinicians on implant choice. Cite this article:
Our intention was to investigate if the highly porous biological fixation surfaces of a new 3D-printed total knee arthroplasty (TKA) achieved adequate fixation of the tibial and patellar components to the underlying bone. A total of 29 patients undergoing primary TKA consented to participate in this prospective cohort study. All patients received a highly porous tibial baseplate and metal-backed patella. Patient-reported outcomes measures were recorded and implant migration was assessed using radiostereometric analysis.Aims
Patients and Methods
The primary objective of this study was to compare migration of the cemented ATTUNE fixed bearing cruciate retaining tibial component with the cemented Press-Fit Condylar (PFC)-sigma fixed bearing cruciate retaining tibial component. The secondary objectives included comparing clinical and radiological outcomes and Patient Reported Outcome Measures (PROMs). A single blinded randomized, non-inferiority study was conducted including 74 patients. Radiostereometry examinations were made after weight bearing, but before hospital discharge, and at three, six, 12, and 24 months postoperatively. PROMS were collected preoperatively and at three, six, 12, and 24 months postoperatively. Radiographs for measuring radiolucencies were collected at two weeks and two years postoperatively.Aims
Methods
The aim of this study was to identify the effect of the manufacturing characteristics of polyethylene acetabular liners on the survival of cementless and hybrid total hip arthroplasty (THA). Prospective cohort study using linked National Joint Registry (NJR) and manufacturer data. The primary endpoint was revision for aseptic loosening. Cox proportional hazard regression was the primary analytical approach. Manufacturing variables included resin type, crosslinking radiation dose, terminal sterilization method, terminal sterilization radiation dose, stabilization treatment, total radiation dose, packaging, and face asymmetry. Total radiation dose was further divided into G1 (no radiation), G2 (> 0 Mrad to < 5 Mrad), G3 (≥ 5 Mrad to < 10 Mrad), and G4 (≥ 10 Mrad).Aims
Methods
A retrospective study was conducted to measure short-term Nonweightbearing supine RSA exams were performed postoperatively and at six, 12, and 24 months. Weightbearing standing RSA exams were performed on select patients at 12 and 24 months. Wear was measured both linearly (joint space) and volumetrically (digital model overlap) at each available follow-up. Precision of both methods was assessed by comparing double RSA exams. Patient age, sex, body mass index, and Oxford Knee Scores were analyzed for any association with PE wear.Aims
Patients and Methods
The aim of this study was to determine the polyethylene wear rate of Phase 3 Oxford Unicompartmental Knee Replacement bearings and to investigate the effects of resin type and manufacturing process. A total of 63 patients with at least ten years’ follow-up with three bearing types (1900 resin machined, 1050 resin machined, and 1050 resin moulded) were recruited. Patients underwent full weight-bearing model-based radiostereometric analysis to determine the bearing thickness. The linear wear rate was estimated from the change in thickness divided by the duration of implantation.Objectives
Methods
Patient-specific instrumentation of total knee arthroplasty (TKA) is a technique permitting the targeting of individual kinematic alignment, but deviation from a neutral mechanical axis may have implications on implant fixation and therefore survivorship. The primary objective of this randomized controlled study was to compare the fixation of tibial components implanted with patient-specific instrumentation targeting kinematic alignment (KA+PSI) A total of 47 patients due to undergo TKA were randomized to KA+PSI (n = 24) or MA+CAS (n = 23). In the KA+PSI group, there were 16 female and eight male patients with a mean age of 64 years (Aims
Patients and Methods
The aim of this study was to determine whether there is a difference
in the rate of wear between acetabular components positioned within
and outside the ‘safe zones’ of anteversion and inclination angle. We reviewed 100 hips in 94 patients who had undergone primary
total hip arthroplasty (THA) at least ten years previously. Patients
all had the same type of acetabular component with a bearing couple
which consisted of a 28 mm cobalt-chromium head on a highly crosslinked
polyethylene (HXLPE) liner. A supine radiostereometric analysis
(RSA) examination was carried out which acquired anteroposterior
(AP) and lateral paired images. Acetabular component anteversion
and inclination angles were measured as well as total femoral head
penetration, which was divided by the length of implantation to
determine the rate of polyethylene wear.Aims
Patients and Methods
The aim of this study was to determine the stability of a new
short femoral stem compared with a conventional femoral stem in
patients undergoing cementless total hip arthroplasty (THA), in
a prospective randomized controlled trial using radiostereometric
analysis (RSA). A total of 53 patients were randomized to receive cementless
THA with either a short femoral stem (MiniHip, 26 patients, mean
age: 52 years, nine male) or a conventional length femoral stem
(MetaFix, 23 patients, mean age: 53 years, 11 male). All patients
received the same cementless acetabular component. Two-year follow-up
was available on 38 patients. Stability was assessed through migration
and dynamically inducible micromotion. Radiographs for RSA were
taken postoperatively and at three, six, 12, 18, and 24 months.Aims
Patients and Methods
Our aim in this study was to describe a continuing review of
11 total hip arthroplasties using 22.225 mm Alumina ceramic femoral
heads on a Charnley flanged femoral component, articulating against
a silane crosslinked polyethylene. Nine patients (11 THAs) were reviewed at a mean of 27.5 years
(26 to 28) post-operatively. Outcome was assessed using the d’Aubigne
and Postel, and Charnley scores and penetration was recorded on
radiographs. In addition, the oxidation of a 29-year-old shelf-aged
acetabular component was analysed.Aims
Patients and Methods
The determination of the volumetric polyethylene wear on explanted material requires complicated equipment, which is not available in many research institutions. Our aim in this study was to present and validate a method that only requires a set of polyetheretherketone balls and a laboratory balance to determine wear. The insert to be measured was placed on a balance, and a ball of the appropriate diameter was inserted. The cavity remaining between the ball and insert caused by wear was filled with contrast medium and the weight of the contrast medium was recorded. The volume was calculated from the known density of the liquid. The precision, inter- and intraobserver reliability, were determined by four investigators on four days using nine inserts with specified wear (0.094 ml to 1.626 ml), and the intra-class correlation coefficient was calculated. The feasibility of using this method in routine clinical practice and the time required for measurement were tested on 84 explanted inserts by one investigator.Objectives
Methods
Hydroxyapatite coatings for uncemented fixation in total knee
arthroplasty can theoretically provide a long-lasting biological
interface with the host bone. The objective of this study was to
test this hypothesis with propriety hydroxyapatite, peri-apatite,
coated tibial components using component migration measured with radiostereometric
analysis over two years as an indicator of long-term fixation. A total of 29 patients at two centres received uncemented PA-coated
tibial components and were followed for two years with radiostereometric
analysis exams to quantify the migration of the component.Aims
Patients and Methods
To compare the structural durability of hydroxyapatite-tricalcium
phosphate (HATCP) to autologous iliac crest bone graft in calcaneal
lengthening osteotomy (CLO) for pes planovalgus in childhood. We present the interim results of ten patients (HATCP, n = 6
and autograft, n = 5) with a mean age of 11.5 years (8.2 to 14.2)
from a randomised controlled non-inferiority trial with six months
follow-up. The primary outcome was the stability of the osteotomy
as measured by radiostereometric analysis. A non-inferiority margin
of ≤ 2 mm osteotomy compression was set.Aims
Patients and Methods
The aim of this study was to quantify the stability
of fracture-implant complex in fractures after fixation. A total
of 15 patients with an undisplaced fracture of the femoral neck,
treated with either a dynamic hip screw or three cannulated hip
screws, and 16 patients with an AO31-A2 trochanteric fracture treated
with a dynamic hip screw or a Gamma Nail, were included. Radiostereometric
analysis was used at six weeks, four months and 12 months post-operatively
to evaluate shortening and rotation. Migration could be assessed in ten patients with a fracture of
the femoral neck and seven with a trochanteric fracture. By four
months post-operatively, a mean shortening of 5.4 mm (-0.04 to 16.1)
had occurred in the fracture of the femoral neck group and 5.0 mm
(-0.13 to 12.9) in the trochanteric fracture group. A wide range
of rotation occurred in both types of fracture. Right-sided trochanteric
fractures seem more rotationally stable than left-sided fractures. This prospective study shows that migration at the fracture site
occurs continuously during the first four post-operative months,
after which stabilisation occurs. This information may allow the
early recognition of patients at risk of failure of fixation. Cite this article:
