Keywords
hip fracture - length of stay - mortality - 30-day mortality - COVID-19 - SARS-CoV-2
The first confirmed case of the novel coronavirus in the United Kingdom was on January
30th, 2020, however, the effects were predominantly felt from March 2020 onward. London
was widely regarded as the epicenter of the initial outbreak (“first wave”) in the
United Kingdom, and was the region with the highest total number of confirmed cases
during this period, with the peak hospital admissions and deaths occurring in April
2020. Since then, further waves have affected a wider geographical distribution throughout
the United Kingdom.[1]
Hip fractures are a cornerstone of trauma workload in Trauma and Orthopaedic Surgery;
they are markers of frailty and usually affect patients with multiple medical problems.
Early during the pandemic, it was recognized that the prevalence of hip fractures
was unlikely to decrease, and it was possible that it could even increase on account
of their usual mechanism (fall from standing height at home) and decreased social
support. Individual units developed tools and pathways, in order to mitigate potential
shortfalls in theatre capacity and availability of resources. A shift from “sickest
first” to “fittest first” was considered, as along with the option of non-operative
treatment for the frailest patients, particularly if medically compromised as a result
of COVID-19.[2]
In response to the rapidly changing situation and unprecedented requirements on the
health care service, elective and planned surgical work was stopped, but the provision
of an emergency service for patients with traumatic injuries continued, with significant
procedural changes in relation to personal protective equipment and logistical considerations
in theatre.
There was a noticeable decrease in other traumatic injuries during this period, due
to lifestyle changes during the lockdown,[3] however, the delivery of surgical care for patients with hip fractures was one of
the very few areas of practice that remained relatively unaffected in terms of the
volume of cases and surgical management.[4]
[5] As a result, the outcomes in this group of patients can be a useful resource in
better understanding the risks involved in delivering surgical treatments during the
COVID-19 pandemic. Hip fracture patients tend to be frail and often poorly optimized
when compared with candidates for elective arthroplasty. In spite of this, these patients
undergo major orthopaedic surgical interventions, and they are currently the most
consistent cohort of patients to extrapolate outcomes from, and may provide useful
information as we plan to return to normal activities internationally.[6]
We aimed to evaluate the 30-day mortality of patients with hip fractures treated in
a busy District General Hospital in London, during the initial peak (“first wave”)
of the COVID-19 pandemic. Additionally, this study aimed to review outcomes in relation
to SARS-CoV-2 antigen swab tests and clinical suspicion of COVID-19, as well as length
of stay (LOS).
Methods
Study Design
This was a retrospective observational study at a district general hospital in London,
United Kingdom. This was a service evaluation exercise and did not require ethical
approval. We defined the study period as February 17th to May 17th, 2020 (study group). This 13-week period was chosen as it includes the significant
initial rise of coronavirus cases from late February onward, the peak seen in early
April and the gradual decrease in cases later on. The control group was defined as
the same 13-week period in the previous year: February 18th to May 19th, 2019.
Study Population
All adult patients managed by our service with a proximal femoral fracture were included.
This included intracapsular, trochanteric, and subtrochanteric fractures. Children,
femoral shaft fractures, distal femoral fractures, and periprosthetic fractures were
excluded.
Data Collection
Patients were identified for the study period using our prospectively maintained trauma
database, and electronic notes were reviewed to determine outcomes including LOS,
mortality, and SARS-CoV-2 antigen swab testing. The control group was identified from
our database of hip fracture patients from 2019, compiled for the National Hip Fracture
Database (NHFD). We evaluated outcomes for the whole year of 2019, as well as for
a period spanning from February 18th to May 19th, 2019 (control group).
Statistical Analysis
Continuous variables (age, comorbidities, and LOS) were presented as mean, standard
deviation, median and range, and checked for normality using a Shapiro-Wilk test.
Results were compared using an independent samples t-test (Student test for parametric data, Mann-Whitney U test for non-parametric data)
and effect size was calculated with rank-biserial correlation in the case of non-parametric
data. Categorical variables (30-day mortality, gender) were presented as frequencies
and percentages, and were compared using a Chi-square test and Phi coefficient to
estimate effect size. Incidence was compared using a Chi-square test. JASP, Version
0.13.1 (University of Amsterdam, Netherlands)[7] was used for statistical analysis.
Results
Incidence, Demographics, 30-Day Mortality, and LOS
Study Group (2020 Data)
Between February 17th and May 17th, 2020, our service admitted 69 patients with hip fractures. Forty-eight of these
(69.6%) were female, and the mean age was 83.1 (SD = 11.1, median = 84.5, range = 40–99).
The mean number of comorbidities was 3.0 (SD = 1.6, median = 3, range = 0–8).
The 30-day mortality rate was 5.8% (four deaths), with a mean time from admission
to death of 17.7 days (SD = 6.4 days, median = 19 days, range 9.2–23.4 days). The
remaining 65 patients had a mean LOS of 11.6 days (SD = 8 days, median = 10 days,
range = 1.9–61 days).
Control Group (2019 Data)
In the whole of 2019, our service treated 326 patients with a hip fracture, and the
30-day mortality rate was 6.13% (20 deaths). In the control group (February 18th to
May 19th, 2019) there were 70 cases, of which 47 were female (67.1%); the mean age was 83.6
(SD = 8.7, median = 84.8, range = 63–98), and the mean number of comorbidities was
2.9 (SD = 1.3, median = 3, range = 1–6). There were no statistically significant differences
between number of cases (69 vs. 70, p = 0.949), gender (69.6 vs. 67.1% female, p = 0.759), mean age (83.1 vs. 83.6, p = 0.838), or mean number of comorbidities (3.0 vs. 2.9, p = 0.978).
The 30-day mortality rate was 7.1% (five deaths), with a mean time from admission
to death of 11.2 days (SD = 10.6 days, median = 6.9 days, range = 3.6–29.3 days).
The remaining 65 patients had a mean LOS of 19.6 days (SD = 11.3 days, median = 17.4
days, range = 7.7–67.5 days). For both groups, the results for number of comorbidities,
age, and LOS did not follow a normal distribution (Shapiro-Wilk p <0.05), so the Mann-Whitney U test was used in all cases.
There was no statistically significant difference between the 30-day mortality rates
in the study and control groups (5.8 vs. 7.1%, p = 0.747, Phi coefficient 0.027). The mean LOS was significantly shorter in the study
group compared with the control group (11.6 vs. 19.6 days, p <0.001, effect size 0.572—medium to large effect). The mean LOS for the whole of
2019 was 18.2 days, which was also significantly longer than in the study group (11.6
vs. 18.2, p <0.001, effect size 0.389), and similar to the control group (19.6 vs. 18.2, p = 0.086, effect size 0.137). The results are summarized in [Table 1].
Table 1
Hip fracture incidence, age, gender, number of comorbidities, 30-day mortality and
mean length of stay during the COVID-19 period in 2020 compared with the equivalent
period in 2019
|
Study group (COVID-19)
February–May 2020
|
Control group
February–May 2019
|
|
|
Number of patients admitted with hip fracture
|
69
|
70
|
p = 0.949
|
|
Age (mean ± SD, [range])
|
83.1 ± 11.1, [40–99]
|
83.6 ± 8.7, [63–98]
|
p = 0.838
|
|
Female
|
69.6% (48)
|
67.1% (47)
|
p = 0.759
|
|
Number of comorbidities
(mean ± SD, [range])
|
3.0 ± 1.6, [0–8]
|
2.9 ± 1.3, [1–6]
|
p = 0.978
|
|
30-day mortality
|
5.8% (4)
|
7.1% (5)
|
p = 0.747
|
|
Mean length of stay (days)
(mean ± SD, [range])
|
11.6 ± 8, [1.9–61]
|
19.6 ± 11.3, [7.7–67.5]
|
p <0.001
|
SARS-CoV-2 Testing
During the study period, 46 patients (66.7%) were tested for SARS-CoV-2 using throat
and nose swab assay with RT-PCR for SARS-CoV-2, with the first test performed on March
22nd, 2020. Out of the remaining 23 patients that never had an antigen swab test, 18 (78.2%)
were admitted in the first 4 weeks of the study period (February 17th–March 15th, 2020). The testing capacity and relevant protocols evolved during this period of
the pandemic. From mid-March to mid-April, patients were tested only if symptomatic,
whereas from mid-April onward, there was universal testing on admission and periodic
retesting during the hospital stay. Patients admitted between March 26th, 2020 and the end of the study period, had a mean of 2.3 tests during their hospital
stay.
Ten patients (14.5%) tested positive for SARS-CoV-2. In terms of isolation and supportive
measures, they were treated in accordance with the trust policy at the time. None
of the patients, who presented before the antigen testing was available, had clinical
suspicion of COVID-19 retrospectively. Patients who tested negative, but had symptoms
suggestive of COVID-19, were isolated and repeatedly tested every few days during
the admission. If these repeated tests were negative, they were considered not to
have had COVID-19. Of the 10 “COVID-19 positive” patients, two (20%) died within 30
days of admission (days 16 and 23), both from respiratory failure. Three more “COVID-19
positive” patients died beyond the 30-day threshold, two from respiratory failure
on days 38 and 49, and the third following a cerebrovascular event on day 92. All
of these patients had significant comorbidities, advanced age, or a combination of
both. Further information is presented in [Table 2].
Table 2
Demographic information, COVID-19 status, and cause of death for mortalities during
the study period
|
No.
|
Age
|
Gender
|
Comorbidities
|
COVID-19 status
|
Days from admission to death
|
Cause of death
|
|
Mortalities within 30 d
|
|
1
|
93
|
F
|
AF, Severe mitral regurgitation, HTN, previous contralateral hip fracture (Hemiarthroplasty)
|
Negative (not tested)
Admitted 20th February
|
22
|
Gradual decline postoperatively from congestive cardiac failure and hospital-acquired
pneumonia. Switch to palliative approach, transferred to palliative unit on day 20
|
|
2
|
88
|
F
|
Dementia, HTN, colitis, macular degeneration
|
Negative (not tested)
Admitted 27th February
|
9
|
Postoperative chest infection, with continued deterioration despite antibiotics. Hypoactive
delirium and presumed aspiration.
|
|
3
|
88
|
M
|
AF, IHD (previous stents), HTN, COPD, T2DM, chronic kidney disease, prostate cancer,
colitis
|
Positive (1st swab)—26th March
|
23
|
Postoperative pneumonia, failure to respond to IV antibiotics, COVID-19 positive on
day 16 post-operatively. Gradual decline despite ward-based supportive treatment (not
a candidate for positive pressure treatment). Switch to palliative approach, died
from COVID-19
|
|
4
|
75
|
M
|
Dementia, COPD
|
Positive (1st swab)—22nd March
|
16
|
Initial good recovery. On day 9 postoperatively became pyrexial and tachypneic. SARS-CoV-2
swab taken (positive) and protocols followed. Gradual decline despite supportive treatment,
died from COVID-19
|
|
COVID-19 positive patients with mortality after 30 d
|
|
5
|
83
|
M
|
Dementia, IHD, HTN, hypercholesterolemia
|
Positive (1st and 2nd swabs)—12th April, 30th April
3rd swab negative—3rd May
|
38
|
Discharged to inpatient rehabilitation on day 6. Readmitted under the medical team
on day 26 with chest pain. Desaturation and COVID-19 positive. Gradual decline despite
supportive treatment and switch to palliative approach.
|
|
6
|
99
|
F
|
Dementia, lacunar infarct, HTN, gastroesophageal reflux disease, hypercholesterolemia
|
Positive (2nd, 3rd and 4th swabs)—8th April, 10th April, 21st April
During re-admission under medical team.
|
49
|
Discharged to Residential Home on day 10. Readmitted on day 23 under medical team
with worsened confusion—desaturation requiring oxygen, and hyponatremia. Gradual deterioration
despite supportive treatment. Died from COVID-19.
|
|
7
|
89
|
F
|
Two previous cerebrovascular events in previous 3 years. Fall caused by further cerebrovascular
event (bilateral MCA infarcts).
|
Positive (3rd swab)—20th April
1st, 2nd, 4th, and 5th swabs negative. Was considered to have recovered from COVID-19 prior to death.
|
92
|
Poor functional recovery post-operatively, hospital acquired pneumonia + COVID-19
positive. Transferred back to stroke ward. Recovered from chest infection, but gradual
decline and switch to palliative approach. Died from cerebrovascular event.
|
Abbreviations: AF, atrial fibrillation; COPD, chronic obstructive pulmonary disease;
HTN, hypertension; IHD, ischemic heart disease; T2DM, type 2 diabetes mellitus.
Discussion
We present a reassuring overview of the outcomes of hip fracture patients admitted
to our unit, during the first wave of the COVID-19 pandemic in the United Kingdom.
There was no statistically significant difference in the 30-day mortality rate of
patients admitted during this period compared to the equivalent period in the previous
year (5.8 vs. 7.1%, p = 0.747). During the two 13-week study periods in 2020 and 2019, there were near
identical numbers of admissions (69 and 70, respectively, p = 0.949), suggesting that the pandemic did not influence the incidence of hip fractures.
The NHFD was established in 2007 and gathers national data for patients with hip fractures
in the United Kingdom. The annual reports include outcomes of key performance indicators
and mortality rates. The national 30-day mortality for patients presenting with hip
fractures is 6.1% (2019 NHFD Report based on 2018 data).[8] There is a well-recognized seasonal variation of mortality following hip fractures,
with higher rates expected during the winter months.[8] We believe that it was important to mitigate this seasonal bias, hence, we elected
to compare the outcomes of the study group to the corresponding period in 2019. The
30-day mortality in the study group (5.8%) was in keeping with the expected seasonal
values, as well as being in line with the 30-day mortality in our unit for the whole
of the previous year.
Sobti et al reported similar findings for hip fracture patients in Surrey, United
Kingdom, during the period from March to May 2020, with 8.46% mortality, and no statistically
significant difference in mortality compared to a similar period in 2019, however,
this group only contained three “COVID-19 positive” patients, suggesting a much lower
prevalence of the virus in this region at the time.[9] Similarly, Malik-Tabassum et al reported no statistically significant differences
in mortality for hip fracture patients in East Sussex, United Kingdom, during this
period, but only had one “COVID-19 positive” patient in the cohort.[10]
When evaluating the “COVID-19 positive” patients in isolation, we found a 30-day mortality
of 20%, increasing to 50% when followed up over a longer period (up to 92 days). Cheung
and Forsh reported on a series of 10 COVID-19 positive patients with hip fractures,
of whom two had respiratory symptoms and eight were asymptomatic. All the patients
underwent surgery within 2 days. There was one death (10%), secondary to presumed
venous thromboembolism and respiratory failure, affecting one of the two symptomatic
patients. Although this is a very small cohort, the authors report that asymptomatic
COVID-19 positive patients, can undergo surgical treatment without a dramatically
increased risk of mortality.[11]
Chui et al reported outcomes following the implementation of a split-site protocol
in a large district general hospital in London. During the period from March 31st to April 30th, 2020, they treated 47 patients with hip fractures, 12 of whom were considered COVID-19
positive (six with positive tests and six with negative tests but with high clinical
suspicion). The remaining 35 “non-COVID” patients were transferred to a “COVID-free”
site in the independent sector. The early mortality rate for the “non-COVID” group
was 5.7%, compared to 25% for the COVID-19 positive group (three deaths). The latter
group was recognized as being inherently at a higher risk based on their medical background.
There was no statistically significant difference in the mortality between the two
groups (p = 0.0971) and the overall mortality reported was 10.6% at a mean follow-up of 24.7
days.[12]
Our findings do not disagree with the multiple reports showing an association between
COVID-19 infection and mortality in hip fracture patients,[13]
[14]
[15]
[16]
[17]
[18]
[19] as well as reports of an association between frailty and mortality in COVID-19 positive
patients.[20] In our series, the group of patients who succumbed to COVID-19 pneumonia was characterized
by a background of significant comorbidities, very advanced age, or a combination
of both. These are typically high-risk patients who, in any given year, have a high
risk of succumbing to a respiratory infection perioperatively. In previous years the
most prevalent pathogen was not well defined, but in 2020 the most prevalent pathogen
was SARS-CoV-2. Irrespective of the causative microorganism, the overall early mortality
rate remained consistent in our department.
LOS was significantly shorter for the COVID-19 group, both when compared to the control
group and the whole of the 2019 cohort. During the months leading to the pandemic,
we recorded significant improvements to the mean LOS in our unit. This was a result
of the implementation of new pathways whilst our service was going through a period
of transformation, aiming to become a hip fracture hub for East London. The trend
for an improved mean LOS possibly contributed to the short LOS recorded during the
pandemic, but it is unlikely to be the sole reason for it; a national drive to discharge
patients from acute beds very likely contributed too.
This study has limitations. Firstly, it is a retrospective look of short-term outcomes
of hip fracture patients receiving surgical treatment during the first wave of the
pandemic. Nevertheless, 30-day mortality is one of the most important indicators of
perioperative performance and was, hence, selected as a primary outcome in this study.
Secondly, hip fracture patients with their inherent high risk, are not representative
of all other patient groups. However, in the context of the coronavirus pandemic,
they were one of the very few groups of patients whose number and treatment were not
dramatically altered, and can be a valuable source of information. Thirdly, the numbers
in this study are fairly small on account of short study periods (two 13-week periods),
but this was a necessary compromise to make in order to succinctly study the period
of interest without a long period of normality either side.
At the time of writing, there are ongoing pressures in relation to COVID-19 internationally,
with considerable variability between countries, which undoubtedly continues to impact
on the care and outcomes for all patients including those with hip fractures. Further
work is needed to characterize the outcomes for patients in the later stages of the
pandemic, as well as any differences which may be present as a result of mutations
in the virus and different environmental factors such as colder weather over the winter
months.
Conclusion
We report reassuring short-term results demonstrating no significant difference in
the 30-day mortality rate of hip fracture patients admitted during the United Kingdom
first wave of the COVID-19 pandemic in 2020, and no increase in LOS. Our findings
agree with existing reports that elderly hip fracture patients with COVID-19 indeed
have a high risk of perioperative mortality, however, our data suggests that overall
mortality was similar in previous years, in which deaths were more commonly attributed
to respiratory infections associated with other pathogens.
