Introduction

Approximately 20-25% of patients having joint replacement in the UK have moderate-severe frailty. Frailty is associated with poorer outcomes after joint replacement. Targeting frailty pre-operatively with exercise and protein supplementation could improve post-operative outcomes. Prior to conducting a randomised controlled trial (RCT), a feasibility study was necessary to inform trial design and delivery.

Introduction

Hip prosthetic joint infection (PJI) is a debilitating complication following joint replacement surgery, with significant impact on patients and healthcare systems. The INFection ORthopaedic Management: Evidence into Practice (INFORM: EP) study, builds upon the 6-year INFORM programme by developing evidence-based guidelines for the identification and management of hip PJI.

Hip bearing surfaces materials are typically broadly reported in national registry (metal-on-polyethylene, ceramic-on-ceramic etc). We investigated the revision rates of primary total hip replacement (THR) reported in the National Joint Registry (NJR) by detailed types of bearing surfaces used.

We analysed THR procedures across all orthopaedic units in England and Wales. Our analyses estimated all-cause and cause-specific revision rates. We identified primary THRs with heads and monobloc cups or modular acetabular component THRs with detailed head and shell/liner bearing material combinations. We used flexible parametric survival models to estimate adjusted hazard ratios (HR).

A total of 1,026,481 primary THRs performed between 2003–2019 were included in the primary analysis (Monobloc cups: n=378,979 and Modular cups: n=647,502) with 20,869 (2%) of these primary THRs subsequently undergoing a revision episode (Monobloc: n=7,381 and Modular: n=13,488).

Compared to implants with a cobalt chrome head and highly crosslinked polyethylene (HCLPE) cup, the overall risk of revision for monobloc acetabular implant was higher for patients with cobalt chrome or stainless steel head and non-HCLPE cup. The risk of revision was lower for patients with a delta ceramic head and HCLPE cup implant, at any post-operative period.

Compared to patients with a cobalt chrome head and HCLPE liner primary THR, the overall risk of revision for modular acetabular implant varied non-constantly. THRs with a delta ceramic or oxidised zirconium head and HCLPE liner had a lower risk of revision throughout the entire post-operative period.

The overall and indication-specific risk of prosthesis revision, at different time points following the initial implantation, is reduced for implants with a delta ceramic or oxidised zirconium head and a HCLPE liner/cup in reference to THRs with a cobalt chrome head and HCLPE liner/cup.

Hip prosthetic joint infection (PJI) is a debilitating complication following joint replacement surgery, with significant impact on patients and healthcare systems. The INFection ORthopaedic Management: Evidence into Practice (INFORM:EP) study, builds upon the 6-year INFORM programme by developing evidence-based guidelines for the identification and management of hip PJI.

A panel of 21 expert stakeholders collaborated to develop best practice guidelines based on evidence from INFORM \[1\]. An expert consensus process was used to refine guidelines using RAND/UCLA criteria. The guidelines were then implemented over a 12-month period through a Learning Collaborative of 24 healthcare professionals from 12 orthopaedic centres in England. Qualitative interviews were conducted with 17 members of the collaborative and findings used to inform the development of an implementation support toolkit. Patient and public involvement contextualised the implementation of the guidelines. The study is registered with the ISCRTN (34710385).

The INFORM guidelines, structured around the stages of PJI management, were largely supported by surgeons, although barriers included limited awareness among non-surgical team members, lack of job planning for multidisciplinary teams, and challenges in ensuring timely referrals from primary care. Psychological support for patients was identified as a critical gap. Advanced Nurse Practitioners and multidisciplinary team (MDT) coordinators were seen as potential bridges to address these knowledge gaps. The guidelines were also viewed as a useful tool for service development.

This study presents the first evidence-based guidelines for hip PJI management, offering a comprehensive approach to prevention, treatment, and postoperative care. Effective implementation is crucial, involving wider dissemination amongst primary and community care, as well as non-specialist treatment centres. Further resources are needed to ensure job planning for MDTs and psychological support for patients. Overall, this study lays the foundation for improved PJI management, benefiting patients and healthcare systems.

Total hip replacement (THR) is one of the most common and cost-effective elective surgical procedures. In the National Health Service (NHS) of England and Wales a myriad of implants for THR are offered at a variety of locally negotiated prices. This study aims to estimate the total burden of elective THR to the NHS, expenditure on implants, and different scenarios of cost changes if implant selection changed for different patient groups.

Using National Joint Registry (NJR) data and NHS reference costs, we estimated the number and expenditure of NHS funded primary and revision THR in the 10-year period 2008–2017 and forecasted the number and expenditure on THR over the next decade. Using NJR average NHS Trust prices for the different implant combinations we estimated the average cost of implants used in THRs and estimated the budget impact on NHS providers from switching to alternative implants.

The NHS spent over £4.76 billion performing 702,381 THRs between 2008–2017. The average cost of implants was £1,260 per surgery, almost a fifth of the cost of primary THR. Providing cemented implant combinations in primary elective THRs may potentially save up to £281 million over the next 10 years, whilst keeping 10-year revision risks low.

The NHS is likely to spend over £5.6 billion providing primary elective THR over the next decade. There are efficiency savings to realise in the NHS by switching to more cost-effective implant combinations available for patients undergoing primary elective THR surgery, but these will need to be balanced against the risks inherent to a change in selection of implants and surgical practice. The HIPPY programme will be conducting practice surveys, discrete choice experiments and a large randomised controlled trial of cemented, uncemented and hybrid fixation in THR for patients under 70 to answer uncertainties.

Implants in total hip replacement (THR) are associated with different clinical and cost-effectiveness profiles,. We estimate the costs and outcomes for NHS patients in the year after THR associated with implant bearing materials using linked routinely collected data.

We linked NJR primary elective THR patients for osteoarthritis to HES and National PROMs. We estimated health care costs, health-related quality of life indices, and revision risks, in the year after primary and revision THRs overall. We used generalised linear models adjusting for patient and hospital characteristics and estimated 10-year cumulative probability of revision. We imputed utilities using chained equations for half the sample with missing PROMS.

We linked 577,973 elective primary THRs and 11,812 subsequent revisions. One year after primary THR, patients with the cemented THRs using cobalt chrome or stainless steel head with HCLPE liner/cup cost the NHS, on average, £13,101 (95%CI £13,080,£13,122), had an average quality-of-life score of 0.788 (95%CI 0.787,0.788), and a 10-year revision probability of 1.9% (95%CI 1.6,2.3). Compared to the reference, patients receiving a cemented THR with delta ceramic head and HCLPE liner/cup, hybrid THR with delta ceramic head and HCLPE liner/cup, and hybrid THR with alumina head and HCLPE liner/cup had lower 1-year costs (-£572 \[95% CI -£775,-£385\], -£346 \[-£501,-£192\], -£371 \[-£574,-£168\] respectively), better quality of life (0.007 \[95% CI 0.003,0.011\], 0.013 \[0.010,0.016\], 0.009 \[0.005,0.013\] respectively), and lower 10-year revision probabilities (1.4% \[1.03,2.0\], 1.5 \[1.3,1.7\], 1.6%\[1.2,2.1\] respectively).

Implant bearing materials are associated with varying mean costs and health outcomes after primary THR. Ours is the first study to derive costs and health outcomes from large, linked databases using multiple imputation methods to deal with bias. Our findings are useful for commissioning and procurement decisions and to inform a subsequent cost-effectiveness model with more granular detail on THR implant types.

Abstract

Abstract

In the unstable patellofemoral joint (PFJ), the patella will articulate in an abnormal manner, producing an uneven distribution of forces. It is hypothesised that incongruency of the PFJ, even without clinical instability, may lead to degenerative changes. The aim of this study was to record the change in joint contact area of the PFJ after stabilisation surgery using an established and validated MRI mapping technique.

A prospective MRI imaging study of patients with a history of PFJ instability was performed. The patellofemoral joints were imaged with the use of an MRI scan during active movement from 0° through to 40° of flexion. The congruency through measurement of the contact surface area was mapped in 5-mm intervals on axial slices. Post-stabilisation surgery contact area was compared to the pre-surgery contact area.

In all, 26 patients were studied. The cohort included 12 male and 14 female patients with a mean age of 26 (15–43). The greatest mean differences in congruency between pre- and post-stabilised PFJs were observed at 0–10 degrees of flexion (0.54 cm² versus 1.18 cm², p = 0.04) and between 11° and 20° flexion (1.80 cm² versus 3.45 cm²; p = 0.01).

PFJ stabilisation procedures increase joint congruency. If a single axial series is to be obtained on MRI scan to compare the pre- and post-surgery joint congruity, the authors recommend 11° to 20° of tibiofemoral flexion as this was shown to have the greatest difference in contact surface area between pre- and post-operative congruency.

Dual-mobility constructs (DMCs) are increasingly used for total hip replacement (THR) following hip fracture.

The aims of this study were to identify whether there was a difference in all-cause construct survival following THR with a DMC (DMC-THR) or with a conventional construct following hip fracture, and to identify the expected net all-cause construct survival for DMC-THR performed for hip fracture.

We performed a systematic review and meta-analysis of published studies (including joint registries) including DMC-THR for hip fracture which provided Kaplan-Meier (KM) survival estimates. The primary outcome was all-cause construct survival over time.

318 papers and 17 registry reports were identified. Three studies (two registry reports and one cohort study utilising joint registry data) met the inclusion criteria, including 8,834 DMC-THRs and 63,865 conventional THRs. Upon meta-analysis, DMC-THRs had lower all-cause construct survival. Five-year KM estimates (95% confidence intervals) were 95.3% (94.6–95.9%) for DMC-THR and 96.1% (95.9–96.3%) for conventional THR.

These results suggest there is a small absolute but not clinically significant all-cause implant survival difference between THR with DMC and conventional implants following hip fracture. Given the higher comparative cost of DMC, this analysis does not support its routine use.

Whilst total hip replacement (THR) is generally safe and effective, pre-existing medical conditions, particularly those requiring inpatient admission, may increase the risk of post-operative mortality. Delaying elective surgery may reduce the risk, but it is unclear how long a delay is sufficient.

We analysed 958,145 primary THRs performed for solely osteoarthritis April 2003-December 2018, in the NJR linked to Hospital Episodes Statistics to identify inpatient admissions prior to elective THR for 17 conditions making up the Charlson index including myocardial infarction, congestive heart failure, cerebrovascular disease and diabetes. Crude analyses used Kaplan-Meier and adjusted analyses used Cox modelling. Patients were categorised for each co-morbidity into one of four groups: not recorded in previous five-years, recorded between five-years and six-months before THR, recorded six-months to three-months before THR, and recorded between three-months and day before surgery.

90-day mortality was 0.34% (95%CI: 0.33–0.35). In the 432 patients who had an acute MI in the three months before THR, this figure increased to 18.1% (95%CI 14.8, 22.0). Cox models observed 63 times increased hazard of death within 90-days if patients had an acute MI in the 3-months before their THR, compared to patients who had not had an MI in the five years before their THR (HR 63.6 (95%CI 50.8, 79.7)) This association reduced as the time between acute MI and THR increased. For congestive cardiac failure, the hazard in the same scenario was 18-times higher with a similar protective effect of delaying surgery.

Linked NJR and HES data demonstrate an association between inpatient admission for acute medical co-morbidities and death within 90-days of THR. This association is greatest in MI, congestive cardiac failure and cerebrovascular disease with smaller associations observed in several other conditions including diabetes. The hazard reduces when longer delays are seen between the admission for acute medical conditions and THR in all diagnoses. This information will help patients with previous medical admissions and surgeons to determine optimal timing for surgery.

The Exeter V40 femoral stem is the most implanted stem in the NJR for primary THA. In 2004, the 44/00/125 stem was released for use in “cement-in-cement” revision cases. It has however been used ‘off-label’ as a primary stem when, for example, patient anatomy requires a smaller stem with a 44mm offset. We aimed to investigate survival of this stem in comparison to others in the range when used in primary THAs recorded in the NJR.

Analyses were performed using a dataset based on that used for the 2020 NJR annual report. Our exposure was the stem; the outcome was all-cause construct revision. Crude analyses were performed using Kaplan-Meier and adjusted using Cox models. The 44/00/125 stem was directly compared to other stems in the Exeter range.

We analysed 330,732 primary THAs using the Exeter V40 stem comprising 34.5% of the 958,869 THAs with complete information from the start of the NJR to 31 December 2018. The 44/00/125 stem was implanted in 2,158 primary THAs with 67.5% in female patients and a mean age of 67.8. The 10-year revision estimate for the 44/00/125 stem was 4.9% (95%CI 3.6, 6.8) and in constructs using an Exeter V40 stem was 2.8% (95%CI 2.7, 2.8). Controlling for age, sex and ASA demonstrated an increased overall hazard of revision for constructs using the 44/00/125 stem compared to constructs using other Exeter V40 femoral stems (HR 1.8 (95%CI 1.4, 2.3)).

Although the revision estimate is within the NICE 10-year benchmark, survivorship of constructs using the 44/00/125 stem appears to be lower than the rest of the Exeter V40 range. Attempts to control for age, sex and ASA will not take into account confounding by indication i.e. patients with more complex anatomy who may have a higher risk of revision. Surgeons and patients should be reassured by this but should be aware of the observed increased revision estimate and use the stem according to its indications.

Abstract

Abstract

Introduction and Objective

The most common paediatric orthopaedic injury requiring hospital admission is a femoral fracture. There is debate regarding the optimal surgical technique for fixing femoral diaphyseal fractures in children aged 4 to 12 years. The National Institute for Health and Care Excellence (NICE) and the American Academy of Orthopaedic Surgeons (AAOS) have issued relevant guidelines, however, there is limited evidence to support these. The aim of this study was to conduct a systematic review and meta-analysis to compare the complication rate following flexible intramedullary nailing (FIN), plate fixation and external fixation (EF) for traumatic femoral diaphyseal fractures in children aged 4 to 12.

Introduction and Objective

An important subset of patients is dissatisfied after total joint arthroplasty (TJA) due to residual functional impairment. This study investigated the assessment of objectively measured step-up performance following TJA, to identify patients with poor functional improvement after surgery, and to predict residual functional impairment during early postoperative rehabilitation. Secondary, longitudinal changes of block step-up (BS) transfers were compared with functional changes of subjective patient reported outcome measures (PROMs) following TJA.

A recent French report suggested that cobalt metal ions released from total hip replacements (THRs) were associated with an increased risk of dilated cardiomyopathy and heart failure. If the association is causal the consequences would be significant given the millions of Orthopaedic procedures in which cobalt-chrome is used annually. We examined whether cobalt-chrome containing THRs were associated with an increased risk of all-cause mortality, heart failure, cancer, and neurodegenerative disorders.

Data from the National Joint Registry was linked to NHS English hospital inpatient episodes for 375,067 primary THRs with up to 14·5 years follow-up. Implants were grouped as either containing cobalt-chrome or not containing cobalt-chrome. The association between implant construct and the risk of all-cause mortality and incident heart failure, cancer, and neurodegenerative disorders was examined.

There were 132,119 individuals (35·2%) with an implant containing cobalt-chrome. There were 48,106 deaths, 27,406 heart outcomes, 35,823 cancers, and 22,097 neurodegenerative disorders. There was no evidence of an association that patients with cobalt-chrome implants had higher rates of any of the outcomes. For all-cause mortality there was a very small survival advantage for patients having a cobalt-chrome implant (restricted mean survival time 13·8=days, 95% CI=6·8-20·9).

Cobalt-chrome containing THRs did not have an increased risk of all-cause mortality, heart failure, cancer, and neurodegenerative disorders into the second decade post-implantation. Our findings will reassure clinicians and patients that primary THR is not associated with systemic implant effects.

Total hip replacements (THRs) are performed by surgeons at various stages in their training, with varying levels of senior supervision. There is a balance between protecting training opportunities for the next generation of surgeons, while limiting the exposure of patients to unnecessary risk during the training process. The aim of this study was to examine the association between surgeon grade, the senior supervision of trainees, and the risk of revision following THR.

We included 603 474 primary THRs recorded in the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man (NJR) between 2003 and 2016 for an indication of osteoarthritis. Exposures were the grade of the surgeon (consultant or trainee), and whether trainees were supervised by a scrubbed consultant or not. Outcomes were all-cause revision, the indication for revision, and the temporal variation in risk of revision (all up to 10 years). Net failure was calculated using Kaplan-Meier analysis and adjusted analyses used Cox regression and flexible parametric survival analysis (adjusted for patient, operative, and unit level factors).

There was no association between surgeon grade and all-cause revision up to 10 years (crude hazard ratio (HR) 0·999, 95% confidence interval (CI) 0.936–1.065; p=0.966); a finding which persisted with adjusted analysis. Adjusted analysis demonstrated an association between trainees operating without supervision by a scrubbed consultant and an increase in all-cause revision (HR 1.100, 95% CI 1.002–1.207; p=0.045). There was an association between the trainee-performed THRs and revision due to instability (crude HR 1.143, 95% CI, 1.007–1.298; p=0.039). However, this was not observed in fully adjusted models, or when trainees were supervised by a scrubbed consultant.

Within the current training system in the United Kingdom, trainees achieve comparable outcomes to consultant surgeons when supervised by a scrubbed consultant. Revision rates are higher when trainees are not supervised by a scrubbed consultant but remain within internationally recognised acceptable limits.

Considerable debate exists regarding which agent(s) should be preferred for venous thromboembolism (VTE) chemical prophylaxis following joint replacement. We assessed the practice of surgeons regarding VTE chemical prophylaxis for primary THR and TKR, pre and post issuing of updated NICE guidance in 2018.

A survey, circulated through the British Hip Society and regional trainee networks/collaboratives, was completed by 306 UK surgeons at 187 units. VTE chemical prophylaxis prescribing patterns for surgeons carrying out primary THR (n=258) and TKR (n=253) in low-risk patients were assessed post publication of 2018 NICE recommendations. Prescribing patterns before and after the NICE publication were subsequently explored. Questions were also asked about surgeon equipoise for participation in future RCTs.

Following the new guidance, 34% (n=87) used low-molecular weight heparin (LMWH) alone, 33% (n=85) aspirin (commonly preceded by LMWH), and 31% (n=81) direct oral anticoagulants (DOACs: with/without preceding LMWH) for THR. For TKR, 42% (n=105) used aspirin (usually monotherapy), 31% (n=78) LMWH alone, and 27% (n=68) DOAC (with/without preceding LMWH). NICE guidance changed the practice of 34% of hip and 41% of knee surgeons, with significantly increased use of aspirin preceded by LMWH for THR (before=25% vs. after=73%;p<0.001), and aspirin for TKR (before=18% vs. after=84%;p<0.001). Significantly more regimens were NICE guidance compliant after the 2018 update for THR (before=85.7% vs. after=92.6%;p=0.011) and TKR (before=87.0% vs. after=98.8%;p<0.001). Support from surgeons for future RCTs was dependent on the clinical question, ranging from 48% participation in trials (effectiveness of aspirin vs. a DOAC) to 79% (effectiveness of 14 days LMWH vs. 28 days LMWH).

Over one-third of surveyed surgeons changed their VTE chemical prophylaxis in response to 2018 NICE recommendations, with more THR and TKR surgeons now compliant with latest NICE guidance. The major change in practice was an increased use of aspirin for VTE chemical prophylaxis. Furthermore, there is an appetite amongst UK surgeons for participating in future RCTs, with a trial comparing standard versus extended duration LMWH likely feasible in current practice.

The aim of this study was to compare the relative performance of total hip replacement constructs and discern if there is substantial variability in performance in currently commonly used prostheses.

All patients who underwent a primary total hip replacement (THR) registered in the NZJR between 1^st January 1999 to June 2020 were identified. Using a noninferiority analysis, the performance of hip prostheses were compared with the best performing contemporary construct. Construct failure was estimated using the 1-Kaplan Meier survival function method to estimate net failure. The difference in failure between the contemporary benchmark and other constructs was examined.

In total 135 432 THR were recorded comprising 1 035 different THR constructs. Notably 328 constructs were used just once. 48 constructs (62 251 THR) had >500 procedures at risk at 3 years post-primary of which 28 were inferior by at least 20% relative risk of which, 10 were inferior by at least 100% relative risk. 16 constructs were identified with >500 procedures at risk at 10 years with 9 inferior by at least 20%, of which one was inferior by >100% relative risk. There were fewer constructs noninferior to the best practice benchmark when we performed analysis by gender. In females at 10 years, from 5 constructs with >500 constructs at risk, 2 were inferior at the 20% margin. In males at 10 years, there were only 2 eligible constructs of which one was inferior at the 20% margin.

We discerned that there is substantial variability in construct performance and at most time points, just over half of constructs are inferior to the best performing construct by at least 20%. These results can facilitate informed decision-making when considering THR surgery.