The mechanisms controlling and limiting movement and serving to transmit load between the femur and the tibia are discussed. Having accounted for the transmission of all components of force and couple across the joint and noted the load-bearing role of the menisci, some principles which might guide the design of knee prostheses are deduced. It is shown that current designs transgress some of these principles. An experimental prosthesis is then described, which incorporates analogues of the natural menisci. The possible practical application of this novel principle has been studied in cadaveric human joints and in living patients.
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
The aim of this study was to conduct the largest low contact stress (LCS) retrieval study to elucidate the failure mechanisms of the Porocoat and Duofix femoral component. The latter design was voluntarily recalled by the manufacturer. Uncemented LCS explants were divided into three groups: Duofix, Porocoat, and mixed. Demographics, polyethylene wear, tissue ingrowth, and metallurgical analyses were performed.Aims
Materials and Methods
The aim of this study was to compare the survivorship and radiographic
outcomes at ten-year follow-up of three prospective consecutive
series of patients each of which received a different design of
cementless femoral components for total hip arthroplasty (THA). In Cohort 1, 91 consecutive patients (100 hips) underwent THA
with a cementless porous-coated anatomic femoral stem (PCA) between
October 1983 and January 1986. In Cohort 2, 86 consecutive patients
(100 hips) underwent THA with an extensively porous-coated cementless
femoral stem (Prodigy) between June 1994 and October 1997. In Cohort
3, 88 consecutive patients (100 hips) underwent THA with a proximally
porous-coated triple-tapered cementless stem (Summit) between April
2002 and October 2003. All three groups underwent prospective clinical
and radiographic evaluation.Aims
Patients and Methods
Progressive retroversion of a cemented stem is
predictive of early loosening and failure. We assessed the relationship
between direct post-operative stem anteversion, measured with CT,
and the resulting rotational stability, measured with repeated radiostereometric
analysis over ten years. The study comprised 60 cemented total hip
replacements using one of two types of matt collared stem with a
rounded cross-section. The patients were divided into three groups
depending on their measured post-operative anteversion (<
10°,
10° to 25°, >
25°). There was a strong correlation between direct
post-operative anteversion and later posterior rotation. At one
year the <
10° group showed significantly more progressive retroversion
together with distal migration, and this persisted to the ten-year
follow-up. In the <
10° group four of ten stems (40%) had been
revised at ten years, and an additional two stems (20%) were radiologically
loose. In the ‘normal’ (10° to 25°) anteversion group there was
one revised (3%) and one loose stem (3%) of a total of 30 stems,
and in the >
25° group one stem (5%) was revised and another loose (5%)
out of 20 stems. This poor outcome is partly dependent on the design
of this prosthesis, but the results strongly suggest that the initial
rotational position of cemented stems during surgery affects the
subsequent progressive retroversion, subsidence and eventual loosening.
The degree of retroversion may be sensitive to prosthetic design
and stem size, but <
10° of anteversion appears deleterious to
the long-term outcome for cemented hip prosthetic stems. Cite this article:
Objectives. The ability to determine human bone stiffness is of clinical relevance in many fields, including bone quality assessment and orthopaedic
Aims. Instability continues to be a troublesome complication after total hip arthroplasty (THA). Patient-related risk factors associated with a higher dislocation risk include the preoperative diagnosis, an age of 75 years or older, high body mass index (BMI), a history of alcohol abuse, and neurodegenerative diseases. The goal of this study was to assess the dislocation rate, radiographic outcomes, and complications of patients stratified as high-risk for dislocation who received a dual mobility (DM) bearing in a primary THA at a minimum follow-up of two years. Materials and Methods. We performed a retrospective review of a consecutive series of DM THA performed between 2010 and 2014 at our institution (Hospital for Special Surgery, New York, New York) by a single, high-volume orthopaedic surgeon employing a single
Literature surrounding artificial intelligence (AI)-related applications for hip and knee arthroplasty has proliferated. However, meaningful advances that fundamentally transform the practice and delivery of joint arthroplasty are yet to be realized, despite the broad range of applications as we continue to search for meaningful and appropriate use of AI. AI literature in hip and knee arthroplasty between 2018 and 2021 regarding image-based analyses, value-based care, remote patient monitoring, and augmented reality was reviewed. Concerns surrounding meaningful use and appropriate methodological approaches of AI in joint arthroplasty research are summarized. Of the 233 AI-related orthopaedics articles published, 178 (76%) constituted original research, while the rest consisted of editorials or reviews. A total of 52% of original AI-related research concerns hip and knee arthroplasty (n = 92), and a narrative review is described. Three studies were externally validated. Pitfalls surrounding present-day research include conflating vernacular (“AI/machine learning”), repackaging limited registry data, prematurely releasing internally validated prediction models, appraising model architecture instead of inputted data, withholding code, and evaluating studies using antiquated regression-based guidelines. While AI has been applied to a variety of hip and knee arthroplasty applications with limited clinical impact, the future remains promising if the question is meaningful, the methodology is rigorous and transparent, the data are rich, and the model is externally validated. Simple checkpoints for meaningful AI adoption include ensuring applications focus on: administrative support over clinical evaluation and management; necessity of the advanced model; and the novelty of the question being answered. Cite this article:
The primary aim of this prospective, multicentre study is to describe the rates of returning to golf following hip, knee, ankle, and shoulder arthroplasty in an active golfing population. Secondary aims will include determining the timing of return to golf, changes in ability, handicap, and mobility, and assessing joint-specific and health-related outcomes following surgery. This is a multicentre, prospective, longitudinal study between the Hospital for Special Surgery, (New York City, New York, USA) and Edinburgh Orthopaedics, Royal Infirmary of Edinburgh, (Edinburgh, UK). Both centres are high-volume arthroplasty centres, specializing in upper and lower limb arthroplasty. Patients undergoing hip, knee, ankle, or shoulder arthroplasty at either centre, and who report being golfers prior to arthroplasty, will be included. Patient-reported outcome measures will be obtained at six weeks, three months, six months, and 12 months. A two-year period of recruitment will be undertaken of arthroplasty patients at both sites.Aims
Methods
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
The aim of this study was to investigate the safety and efficacy of 3D-printed modular prostheses in patients who underwent joint-sparing limb salvage surgery (JSLSS) for malignant femoral diaphyseal bone tumours. We retrospectively reviewed 17 patients (13 males and four females) with femoral diaphyseal tumours who underwent JSLSS in our hospital.Aims
Methods
The aim of this study was to estimate the clinical and economic burden of dislocation following primary total hip arthroplasty (THA) in England. This retrospective evaluation used data from the UK Clinical Practice Research Datalink database. Patients were eligible if they underwent a primary THA (index date) and had medical records available 90 days pre-index and 180 days post-index. Bilateral THAs were excluded. Healthcare costs and resource use were evaluated over two years. Changes (pre- vs post-THA) in generic quality of life (QoL) and joint-specific disability were evaluated. Propensity score matching controlled for baseline differences between patients with and without THA dislocation.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
The aim of this study was to investigate the outcome of periprosthetic fractures of the humerus and to assess the uniformity of the classifications used for these fractures (including those around elbow and/or shoulder arthroplasties) by performing a systematic review of the literature. A systematic search was conducted using the National Institute for Health and Care Excellence Healthcare Databases Advance Search. For inclusion, studies had to report clinical outcomes following the management of periprosthetic fractures of the humerus. The protocol was registered on the PROSPERO database.Aims
Methods
The aim of this study was to investigate the feasibility of application of a 3D-printed megaprosthesis with hemiarthroplasty design for defects of the distal humerus or proximal ulna following tumour resection. From June 2018 to January 2020, 13 patients with aggressive or malignant tumours involving the distal humerus (n = 8) or proximal ulna (n = 5) were treated by en bloc resection and reconstruction with a 3D-printed megaprosthesis with hemiarthroplasty, designed in our centre. In this paper, we summarize the baseline and operative data, oncological outcome, complication profiles, and functional status of these patients.Aims
Methods
Large-diameter metal-on-metal (MoM) total hip arthroplasty (THA) has demonstrated unexpected high failure rates and pseudotumour formation. The purpose of this prospective cohort study is to report ten-year results in order to establish revision rate, prevalence of pseudotumour formation, and relation with whole blood cobalt levels. All patients were recalled according to the guidelines of the Dutch Orthopaedic Association. They underwent clinical and radiographical assessments (radiograph and CT scan) of the hip prosthesis and whole blood cobalt ion measurements. Overall, 94 patients (95 hips) fulfilled our requirements for a minimum ten-year follow-up.Aims
Methods
This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads. In all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity. Half of each head size group were then cycled with simulated gait and the other half with gait compression only. Damage was measured by area and maximum linear wear depth.Aims
Methods