Introduction. Mechanical or corrosive failure of total knee arthroplasties (TKAs) is difficult to diagnose with current laboratory and radiographic analyses. As such, the goal of this study was to determine the mean blood concentration of cobalt, chromium, and titanium in a series of revision TKAs with mechanical
Abstract. Introduction. The aims of our systematic review were to assess the Nickel sensitising potential of total knee arthroplasty (TKA), explore the relationship between Nickel hypersensitivity and clinical outcomes, and evaluate the utility of skin patch testing pre- and/or post-operatively. Methodology. A literature search was performed through EMBASE, Medline and PubMed databases. Articles were screened independently by two investigators. Levels of Evidence were assessed using Oxford CEBM criteria and quality was assessed using MINORS and Cochrane risk-of-bias tools. Results. Twenty studies met the eligibility criteria, reporting on 1354 TKAs. Prevalence of Nickel hypersensitivity ranged from 0% to 87.5%. Only one study which compared prevalence of hypersensitivity in the same patient group before and after surgery noted newly positive patch test reactions in 4.1%. Three studies reported lower prevalence of hypersensitivity in post-operative patients compared to pre-operative patients. Seven studies suggested hypersensitivity might cause complications; six studies did not support any relationship. Seven studies recommended pre-operative patch testing in patients with history of metal allergy; nine studies concluded testing may be valuable post-operatively. Conclusions. Patients undergoing TKA do not seem to be at increased risk of developing Nickel hypersensitivity, and there is conflicting evidence that patients with established hypersensitivity are more likely to experience adverse clinical outcomes. The evidence suggests performing patch testing pre-operatively in patients with history of metal allergy to aid selection of the most appropriate prosthesis, and post-operatively once common causes of
Abstract. Introduction. The number of total knee replacements (TKRs) performed continues to increase and is marked in patients under the age of 60. Increased number of younger patients raises concerns about potentially increased rates of
Abstract. Introduction. OtisMed Shape Match ® patient specific implant cutting jigs were designed to place TKA in kinematic alignment (KA) rather than traditional mechanical alignment (MA). This product was withdrawn from the market in 2013. It has been hypothesised that KA might lead to early
Aims. Endoprosthetic reconstruction with a distal femoral arthroplasty (DFA) can be used to treat distal femoral bone loss from oncological and non-oncological causes. This study reports the short-term implant survivorship, complications, and risk factors for patients who underwent DFA for non-neoplastic indications. Methods. We performed a retrospective review of 75 patients from a single institution who underwent DFA for non-neoplastic indications, including aseptic loosening or mechanical failure of a previous prosthesis (n = 25), periprosthetic joint infection (PJI) (n = 23), and native or periprosthetic distal femur fracture or nonunion (n = 27). Patients with less than 24 months’ follow-up were excluded. We collected patient demographic data, complications, and reoperations. Reoperation for
Aims. Patellofemoral arthroplasty (PFA) has experienced significant
improvements in implant survivorship with second generation designs.
This has renewed interest in PFA as an alternative to total knee
arthroplasty (TKA) for younger active patients with isolated patellofemoral
osteoarthritis (PF OA). We analysed the cost-effectiveness of PFA versus TKA
for the management of isolated PF OA in the United States-based
population. Patients and Methods. We used a Markov transition state model to compare cost-effectiveness
between PFA and TKA. Simulated patients were aged 60 (base case)
and 50 years. Lifetime costs (2015 United States dollars), quality-adjusted
life year (QALY) gains and incremental cost-effectiveness ratio
(ICER) were calculated from a healthcare payer perspective. Annual rates
of revision were derived from the National Joint Registry for England,
Wales, Northern Ireland and the Isle of Man. Deterministic and probabilistic
sensitivity analysis was performed for all parameters against a
$50 000/QALY willingness to pay. . Results. PFA was more expensive ($49 811 versus $46 632)
but more effective (14.3 QALYs versus 13.3 QALYs)
over a lifetime horizon. The ICER associated with the additional
effectiveness of PFA was $3097. The model was mainly sensitive to utility
values, with PFA remaining cost-effective when its utility exceeded
that of TKA by at least 1.0%. PFA provided incremental benefits
at no increased cost when annual rates of revision decreased by
24.5%. . Conclusions. Recent improvements in rates of implant of survival have made
PFA an economically beneficial joint-preserving procedure in younger
patients, delaying TKA until
Aims. Antibiotic-loaded bone cements (ALBCs) may offer early protection against the formation of bacterial biofilm after joint arthroplasty. Use in hip arthroplasty is widely accepted, but there is a lack of evidence in total knee arthroplasty (TKA). The objective of this study was to evaluate the use of ALBC in a large population of TKA patients. Materials and Methods. Data from the National Joint Registry (NJR) of England and Wales were obtained for all primary cemented TKAs between March 2003 and July 2016. Patient, implant, and surgical variables were analyzed. Cox proportional hazards models were used to assess the influence of ALBC on risk of revision. Body mass index (BMI) data were available in a subset of patients. Results. Of 731 214 TKAs, 15 295 (2.1%) were implanted with plain cement and 715 919 (97.9%) with ALBC. There were 13 391 revisions; 2391 were performed for infection. After adjusting for other variables, ALBC had a significantly lower risk of revision for any cause (hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77 to 0.93; p < 0.001). ALBC was associated with a lower risk of revision for all aseptic causes (HR 0.85, 95% CI 0.77 to 0.95; p < 0.001) and revisions for infection (HR 0.84, 95% CI 0.67 to 1.01; p = 0.06). The results were similar when BMI was added into the model, and in a subanalysis where surgeons using only ALBC over the entire study period were excluded. Prosthesis survival at ten years for TKAs implanted with ALBC was 96.3% (95% CI 96.3 to 96.4) compared with 95.5% (95% CI 95.0 to 95.9) in those implanted with plain cement. On a population level, where 100 000 TKAs are performed annually, this difference represents 870 fewer revisions at ten years in the ALBC group. Conclusion. After adjusting for a range of variables, ALBC was associated with a significantly lower risk of revision in this registry-based study of an entire nation of primary cemented knee arthroplasties. Using ALBC does not appear to increase midterm
Aims. Primary (or spontaneous) and secondary osteonecrosis of the knee
can lead to severe joint degeneration, for which either total or
unicompartmental arthroplasty may be considered. However, there
are limited studies analyzing outcomes of unicompartmental knee arthroplasties
(UKAs) for osteonecrosis involving an isolated compartment of the
knee. The aims of this study were to analyze outcomes of UKAs for
osteonecrosis with specific focus on 1) survivorship free of any
revision or reoperation, 2) risk factors for failure, 3) clinical outcomes,
and 4) complications. Patients and Methods. A total of 45 patients underwent 46 UKAs for knee osteonecrosis
between 2002 and 2014 at our institution (The Mayo Clinic, Rochester,
Minnesota). Twenty patients (44%) were female; the mean age of the
patients was 66 years, and mean body mass index (BMI) was 31 kg/m. 2. Of
the 46 UKAs, 44 (96%) were medial UKAs, and 35 (76%) were fixed-bearing
design. Mean mechanical axis postoperatively was 1.5° varus (0°
to 5° varus); 41 UKAs (89%) were performed for primary osteonecrosis.
Mean follow-up was five years (2 to 12). Results. Survivorship free of any revision in the cohort was 89% (95%
CI 77 to 99) and 76% (95% CI 53 to 99) at five and ten years, respectively.
In patients undergoing UKA for primary osteonecrosis survivorship
free of any revision was 93% (95% CI 83 to 100)at both five and ten
years. Secondary osteonecrosis was a significant risk factor for
poorer survivorship free of any revision or reoperation (hazard
ratio 7.7, p = 0.03). Three medial UKAs (6.5%) were converted to
total knee arthroplasties (TKAs): two for lateral compartment degeneration and
one for development of lateral osteonecrosis. No implants were revised
for loosening, fracture, or wear. Knee Society scores improved from
a mean of 60 (44 to 72) preoperatively to a mean of 94 postoperatively
(82 to 100) (p < 0.001). There were no surgical complications. Conclusion. When done for primary osteonecrosis of the knee, UKA resulted
in reliable clinical improvement, minimal complications, and durable
estimated implant survivorship free of revision at ten years. UKA
done for secondary osteonecrosis was substantially less durable
at mid-term follow-up. Progression of knee degeneration, rather
than
The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery. A total of 454 consecutive patients who underwent cementless TKA between August 2004 and December 2021 were reviewed. The mean follow-up was ten years. Plain radiographs were analyzed for radiolucent lines. Patients who underwent revision TKA were recorded, and the cause for revision was determined. Data from the National Joint Registry for England, Wales, Northern Island, the Isle of Man and the States of Guernsey (NJR) were compared with our series.Aims
Methods
Revision total knee arthroplasty (rTKA) is a technically challenging and costly procedure. It is well-documented that primary TKA (pTKA) have better survivorship than rTKA; however, we were unable to identify any studies explicitly investigating previous rTKA as a risk factor for failure following rTKA. The purpose of this study is to compare the outcomes following rTKA between patients undergoing index rTKA and those who had been previously revised. This retrospective, observational study reviewed patients who underwent unilateral, aseptic rTKA at an academic orthopaedic speciality hospital between June 2011 and April 2020 with > one-year of follow-up. Patients were dichotomized based on whether this was their first revision procedure or not. Patient demographics, surgical factors, postoperative outcomes, and re-revision rates were compared between the groups.Aims
Methods
Unicompartmental knee arthroplasty (UKA) has higher revision rates than total knee arthroplasty (TKA). As revision of UKA may be less technically demanding than revision TKA, UKA patients with poor functional outcomes may be more likely to be offered revision than TKA patients with similar outcomes. The aim of this study was to compare clinical thresholds for revisions between TKA and UKA using revision incidence and patient-reported outcomes, in a large, matched cohort at early, mid-, and late-term follow-up. Analyses were performed on propensity score-matched patient cohorts of TKAs and UKAs (2:1) registered in the New Zealand Joint Registry between 1 January 1999 and 31 December 2019 with an Oxford Knee Score (OKS) response at six months (n, TKA: 16,774; UKA: 8,387), five years (TKA: 6,718; UKA: 3,359), or ten years (TKA: 3,486; UKA: 1,743). Associations between OKS and revision within two years following the score were examined. Thresholds were compared using receiver operating characteristic analysis. Reasons for aseptic revision were compared using cumulative incidence with competing risk.Aims
Methods
We explored the literature surrounding whether
allergy and hypersensitivity has a clinical basis for implant selection
in total knee arthroplasty (TKA). In error, the terms hypersensitivity
and allergy are often used synonymously. Although a relationship
is present, we could not find any evidence of
The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design. This was a retrospective review of 707 primary TKAs in 590 patients from a single institution, using a cementless, metal-backed patellar component with a mean follow-up of 6.9 years (2 to 12). A total of 409 TKAs were performed in 338 females and 298 TKAs in 252 males. The mean age of the patients was 63 years (34 to 87) and their mean BMI was 34.3 kg/m2 (18.8 to 64.5). The patients were chosen to undergo a cementless procedure based on age and preoperative radiological and intraoperative bone quality. Outcome was assessed using the Knee Society knee and function scores and range of motion (ROM), complications, and revisions.Aims
Methods
Obtaining solid implant fixation is crucial in revision total knee arthroplasty (rTKA) to avoid aseptic loosening, a major reason for re-revision. This study aims to validate a novel grading system that quantifies implant fixation across three anatomical zones (epiphysis, metaphysis, diaphysis). Based on pre-, intra-, and postoperative assessments, the novel grading system allocates a quantitative score (0, 0.5, or 1 point) for the quality of fixation achieved in each anatomical zone. The criteria used by the algorithm to assign the score include the bone quality, the size of the bone defect, and the type of fixation used. A consecutive cohort of 245 patients undergoing rTKA from 2012 to 2018 were evaluated using the current novel scoring system and followed prospectively. In addition, 100 first-time revision cases were assessed radiologically from the original cohort and graded by three observers to evaluate the intra- and inter-rater reliability of the novel radiological grading system.Aims
Methods
The aim of this study was to determine whether obesity had a detrimental effect on the long-term performance and survival of medial unicompartmental knee arthroplasties (UKAs). This study reviewed prospectively collected functional outcome scores and revision rates of all medial UKA patients with recorded BMI performed in Christchurch, New Zealand, from January 2011 to September 2021. Patient-reported outcome measures (PROMs) were the primary outcome of this study, with all-cause revision rate analyzed as a secondary outcome. PROMs were taken preoperatively, at six months, one year, five years, and ten years postoperatively. There were 873 patients who had functional scores recorded at five years and 164 patients had scores recorded at ten years. Further sub-group analysis was performed based on the patient’s BMI. Revision data were available through the New Zealand Joint Registry for 2,323 UKAs performed during this time period.Aims
Methods
This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up. From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed.Aims
Methods
This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision. A total of 780 patients (39% male; median age 70.7 years (IQR 62.0 to 77.2)) underwent cemented TKA using the Attune Knee System) at five centres, and with the latest radiograph available for the evaluation of RLL at between six and 36 months from surgery. Univariate and multivariate logistic regression models were performed to assess associations between patient and implant-associated factors on the presence of tibial and femoral RLLs. Differences in revision risk depending on RLLs and tibial baseplate design were investigated with the log-rank test.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
The aim of this study was to assess factors associated with the estimated lifetime risk of revision surgery after primary knee arthroplasty (KA). All patients from the Scottish Arthroplasty Project dataset undergoing primary KA during the period 1 January 1998 to 31 December 2019 were included. The cumulative incidence function for revision and death was calculated up to 20 years. Adjusted analyses used cause-specific Cox regression modelling to determine the influence of patient factors. The lifetime risk was calculated as a percentage for patients aged between 45 and 99 years using multiple-decrement life table methodology.Aims
Methods
Periprosthetic joint infection (PJI) occurs in approximately 1% to 2% of total knee arthroplasties (TKA) presenting multiple challenges, such as difficulty in diagnosis, technical complexity, and financial costs. Two-stage exchange is the gold standard for treating PJI but emerging evidence suggests 'two-in-one' single-stage revision as an alternative, delivering comparable outcomes, reduced morbidity, and cost-effectiveness. This study investigates five-year results of modified single-stage revision for treatment of PJI following TKA with bone loss. Patients were identified from prospective data on all TKA patients with PJI following the primary procedure. Inclusion criteria were: revision for PJI with bone loss requiring reconstruction, and a minimum five years’ follow-up. Patients were followed up for recurrent infection and assessment of function. Tools used to assess function were Oxford Knee Score (OKS) and American Knee Society Score (AKSS).Aims
Methods