The Impact of Frailty and Deprivation on the Likelihood of Receiving Primary Total Hip and Knee Arthroplasty among People with Hip and Knee Osteoarthritis

BACKGROUND

Among people with hip and knee osteoarthritis (OA), increasing deprivation is associated with reduced likelihood of receiving hip and knee arthroplasty (THA, TKA).

OBJECTIVES

To assess whether higher levels of frailty in the most deprived neighbourhoods explains the association between greater neighbourhood deprivation and reduced likelihood of receiving THA and TKA among people with hip and knee OA.

DESIGN

Longitudinal cohort study.

SETTING

Linked primary and secondary care electronic medical records and national mortality data.

PARTICIPANTS

104,913 individuals with incident hip OA and 216,420 with incident knee OA.

MEASUREMENTS

Frailty was assessed using a frailty index and categorised as fit, mild, moderate, and severe frailty. Neighbourhood deprivation was assessed using the index of multiple deprivation (IMD).

RESULTS

Compared to those in neighbourhoods in the least deprived quintile of IMD, those in neighbourhoods in the fourth and fifth quintile of IMD (most deprived), respectively, were less likely to receive THA, adjusted subhazard ratio (95% CI), 0.90 (0.87, 0.93) and 0.77 (0.74, 0.80), over a mean follow up of 4.4 years, with similar results for TKA. Higher levels of frailty at OA diagnosis were associated also with reduced likelihood of receiving THA and TKA. The association, however, between deprivation and likelihood of receiving THA and TKA could not be explained by increased levels of frailty among those living in the most deprived areas.

CONCLUSIONS

Further work is needed to understand why those in the most deprived areas are less likely to receive THA and TKA.

1025 THE IMPACT OF DEPRIVATION AND FRAILTY ON THE LIKELIHOOD OF RECEIVING HIP AND KNEE ARTHROPLASTY DUE TO OSTEOARTHRITIS

Introduction

We determined the impact of deprivation and frailty at the time of diagnosis of hip or knee osteoarthritis (OA) on the likelihood of receiving total hip/knee arthroplasty (THA/TKA).

Method

We used routinely collected primary care data (Clinical Practice Research Datalink), linked to Hospital Episode Statistics. Frailty was assessed at the time of OA diagnosis using the electronic frailty index and categorised as fit, mild, moderate, and severe frailty. The association between quintile of index of multiple deprivation (IMD), frailty category and likelihood of receiving THA and TKA was assessed in separate Cox regression models, adjusted for year of OA diagnosis, age, and sex.

Results

104,672 individuals with hip OA and 220,714 with knee OA contributed data. Compared to those in the first quintile of IMD (least deprived), those in the fourth and fifth quintile of IMD (most deprived), respectively, were less likely to receive THA, hazard ratio (HR) (95% CI), 0.92 (0.89, 0.95) and 0.80 (0.77, 0.83), with similar results for TKA. Increasing frailty at OA diagnosis was associated with reduced likelihood of receiving THA/TKA. Compared to fit individuals, the HR (95% CI) for receiving THA and TKA, respectively among those with severe frailty was 0.42 (0.39, 0.45) and 0.57 (0.53, 0.61). Increasing deprivation was associated with increasing frailty at the time of hip/knee OA diagnosis, independent of age, sex, and year of OA diagnosis. However, those in the two most deprived quintiles were still less likely to receive THA/TKA after additionally adjusting for frailty category.

Conclusion

Increased deprivation and increased frailty category were associated with a lower likelihood of receiving THA/TKA among people with hip/knee OA. Increased frailty did not, however, explain the reduced likelihood of receiving THA/TKA among those living in the most deprived areas.

1024 THE IMPACT OF FRAILTY ON 30-DAY MORTALITY FOLLOWING PRIMARY HIP AND KNEE ARTHROPLASTY DUE TO OSTEOARTHRITIS

Introduction

We determined the association between frailty and 30-day mortality following total hip and knee arthroplasty (THA/TKA) due to osteoarthritis and also the impact of THA/TKA on 30-day mortality compared to a control population.

Method

We used linked primary and secondary care data and Office for National Statistics mortality data. Frailty was assessed using the electronic frailty index and categorised as fit, mild, moderate, and severe frailty. The association between frailty and 30-day mortality following THA/TKA was assessed using Cox regression, adjusted for year of birth, sex, quintile of index of multiple deprivation and year of surgery. Mortality following THA/TKA was also compared to a control population who had osteoarthritis but no previous THA/TKA, matched on year of birth, sex, and quintile of index of multiple deprivation.

Results

103,563 cases who had a THA, 125,367 who had a TKA, and matched controls contributed data. Among those who had surgery, 30-day mortality increased with increasing frailty; adjusted hazard ratio (HR) (95% CI) among severely frail vs fit: following THA, 2.85 (1.84, 4.39); following TKA, 2.14 (1.29, 3.53). Compared to fit controls who did not have surgery, 30-day mortality was higher among fit people who had THA and TKA, respectively, adjusted HR 1.60 (1.15, 2.21) and 2.98 (1.81, 4.89). There was, however, no statistically significant difference in 30-day mortality among cases with mild, moderate and severe frailty compared to controls in the same frailty category.

Conclusion

Among people who had THA and TKA, 30-day mortality increased with increasing frailty. A healthy surgery (selection) effect may have impacted on the comparison of mortality among cases who had THA/TKA and controls who did not have surgery.

Does the publication of NICE guidelines for venous thromboembolism chemical prophylaxis influence the prescribing patterns of UK hip and knee surgeons?

INTRODUCTION

We assessed the practice of surgeons regarding venous thromboembolism (VTE) chemical prophylaxis for total hip replacement (THR) and total knee replacement (TKR), before and after issuing of updated National Institute for Health and Care Excellence (NICE) guidance in 2018.

METHODS

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 was assessed after publication of 2018 NICE recommendations. Prescribing patterns before and after the NICE publication were subsequently explored.

RESULTS

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 surgeons 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).

CONCLUSION

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.

Modified conventional gait model vs. Six degrees of freedom model: A comparison of lower limb kinematics and associated error

BACKGROUND

The conventional gait model (CGM) is commonly utilised within clinical motion analysis but has a number of inherent limitations. To overcome some of these limitations modifications have been made to the CGM and six-degrees of freedom models (6DoF) have been developed.

RESEARCH QUESTION

How comparable are lower limb kinematics calculated using modified CGM and 6DoF models and what is the error associated with the output of each model during walking?

METHODS

Ten healthy males attended two gait analysis sessions, in which they walked at a self-selected pace, while a 10-camera motion capture system recorded lower limb kinematics. Hip, knee and ankle joint kinematics in all three anatomical planes were calculated using a modified CGM, with medial anatomical markers and a three-dimensional foot added, and 6DoF. Mean absolute differences were calculated on a point-by-point basis over the walking gait cycle and interpreted relative to a 5° threshold to explore the comparability of model outputs. The standard error of the measurement (SEM) was also calculated on a point-by-point basis over the walking gait cycle for each model.

RESULTS

Mean absolute differences above 5° were reported between the two model outputs in 58-86% of the walking gait cycle at the knee in the frontal plane, and over the entire walking gait cycle at the hip and knee in the transverse plane. SEM was typically larger for the modified CGM compared to the 6DoF, with the highest SEM values reported at the knee in the frontal plane, and the hip and the knee in the transverse plane.

SIGNIFICANCE

Caution should be taken when looking to compare findings between studies utilising modified CGM and 6DoF outside of the sagittal plane, especially at the hip and knee. The reduced SEM associated with the 6DoF suggests this modelling approach may be preferable.

International metal-on-metal multidisciplinary teams: do we manage patients with metal-on-metal hip arthroplasty in the same way? An analysis from the International Specialist Centre Collaboration on MOM Hips (ISCCoMH)

AIMS

There are many guidelines that help direct the management of patients with metal-on-metal (MOM) hip arthroplasties. We have undertaken a study to compare the management of patients with MOM hip arthroplasties in different countries.

METHODS

Six international tertiary referral orthopaedic centres were invited to participate by organising a multi-disciplinary team (MDT) meeting, consisting of two or more revision hip arthroplasty surgeons and a musculoskeletal radiologist. A full clinical dataset including history, blood tests and imaging for ten patients was sent to each unit, for discussion and treatment planning. Differences in the interpretation of findings, management decisions and rationale for decisions were compared using quantitative and qualitative methods.

RESULTS

Overall agreement between the orthopaedic centres and the recommended treatment plans for the ten patients with MOM hip implants was moderate (kappa = 0.6). Full agreement was seen in a third of cases, however split decisions were also seen in a third of cases. Units differed in their interpretation of the significance of the investigation findings and put varying emphasis on serial changes, in the presence of symptoms.

DISCUSSION

In conclusion, the management of raised or rising blood metal ions, cystic pseudotumours and peri-acetabular osteolysis led to inconsistency in the agreement between centres. Coordinated international guidance and MDT panel discussions are recommended to improve consensus in decision making.

TAKE HOME MESSAGE

A lack of evidence and the subsequent variation in regulator guidance leads to differences in opinions, the clinical impact of which can be reduced through a multi-disciplinary team approach to managing patients with MOM hip implants. Cite this article: Bone Joint J 2016;98-B:179-86.

The use of a novel bone allograft wash process to generate a biocompatible, mechanically stable and osteoinductive biological scaffold for use in bone tissue engineering

Fresh-frozen biological allograft remains the most effective substitute for the 'gold standard' autograft, sharing many of its osteogenic properties but, conversely, lacking viable osteogenic cells. Tissue engineering offers the opportunity to improve the osseointegration of this material through the addition of mesenchymal stem cells (MSCs). However, the presence of dead, immunogenic and potentially harmful bone marrow could hinder cell adhesion and differentiation, graft augmentation and incorporation, and wash procedures are therefore being utilized to remove the marrow, thereby improving the material's safety. To this end, we assessed the efficiency of a novel wash technique to produce a biocompatible, biological scaffold void of cellular material that was mechanically stable and had osteoinductive potential. The outcomes of our investigations demonstrated the efficient removal of marrow components (~99.6%), resulting in a biocompatible material with conserved biomechanical stability. Additionally, the scaffold was able to induce osteogenic differentiation of MSCs, with increases in osteogenic gene expression observed following extended culture. This study demonstrates the efficiency of the novel wash process and the potential of the resultant biological material to serve as a scaffold in bone allograft tissue engineering.

Oculomotor nerve palsy following submucosal diathermy to the inferior turbinates

Submucosal diathermy to the inferior turbinates is a common surgical procedure performed to improve the nasal airway. We present the case of a previously well six-year-old boy who underwent submucosal diathermy and developed the unusual complication of a left oculomotor nerve palsy. The possible aetiology is discussed.

Alar haematoma

We present two cases of alar haematoma. This is a very rare complication of nasal trauma, and only two cases have been described previously. One case presented late and did not undergo surgical drainage and has a persistent cosmetic deformity. We recommend early surgical drainage when possible.

Does Kapandji wiring help in older patients? A retrospective comparative review of displaced intra-articular distal radial fractures in patients over 55 years

Forty-six patients aged 55-90 with intra-articular displaced fractures of the distal radius were reviewed retrospectively. All patients were treated with either manipulation and plaster of Paris or Kapandji wiring. Radiographic and functional review was performed by an independent observer a mean of 17 months after the fracture. The results showed superior anatomical and functional results in the group treated with Kapandji wiring. The mean dorsal angle was significantly better in the wired group, and the improvement in dorsal angle, radial angle and radial length from presentation to final result was also significantly better. Functional results were excellent or good in 19/23 of the wired group, compared with 12/23 of the plaster group. There was a strong correlation between functional outcome and both dorsal angle and radial length at union. These results support the use of this method of wire fixation in older patients, as the technique is simple and complications were few.

Reported benefits and problems experienced with bone-anchored hearing aids

Within this study we have examined the self-reported benefits and shortcomings experienced by patients fitted with bone-anchored hearing aids using an open-ended approach developed for hearing aid users. Reports were obtained from 39 patients who, between them, listed 165 benefits and 105 shortcomings. Benefits and shortcomings could be sub-divided into four main groups: practical, acoustical, psychological and medical, in that order of frequency. The most commonly reported benefits included hearing better and clearer, ease of use, inconspicuousness, and the fact that it made the individual more confident. The main shortcomings were difficulties with the telephone, wind noise and hearing speech in noise.