Modern metal-on-metal hip resurfacing has been
widely performed in the United Kingdom for over a decade. However,
the literature reports conflicting views of the benefits: excellent
medium- to long-term results with some brands in specific subgroups,
but high failure rates and local soft-tissue reactions in others.
The National Joint Registry for England and Wales (NJR) has collected
data on all hip resurfacings performed since 2003. This retrospective
cohort study recorded survival time to revision from a resurfacing
procedure, exploring risk factors independently associated with
failure. All patients with a primary diagnosis of osteoarthritis
who underwent resurfacing between 2003 and 2010 were included in
the analyses. Cox’s proportional hazard models were used to analyse
the extent to which the risk of revision was related to patient,
surgeon and implant covariates. A total of 27 971 hip resurfacings were performed during the
study period, of which 1003 (3.59%) underwent revision surgery.
In the final adjusted model, we found that women were at greater
risk of revision than men (hazard ratio (HR) = 1.30, p = 0.007),
but the risk of revision was independent of age. Of the implant-specific
predictors, five brands had a significantly greater risk of revision
than the Birmingham Hip Resurfacing (BHR) (ASR: HR = 2.82, p <
0.001,
Conserve: HR = 2.03, p <
0.001, Cormet: HR = 1.43, p = 0.001,
Durom: HR = 1.67, p <
0.001, Recap: HR = 1.58, p = 0.007). Smaller
femoral head components were also significantly more likely to require
revision (≤ 44 mm: HR = 2.14, p <
0.001, 45 to 47 mm: HR = 1.48,
p = 0.001) than medium or large heads, as were operations performed
by low-volume surgeons (HR = 1.36, p <
0.001). Once these influences
had been removed, in 4873 male patients <
60 years old undergoing
resurfacing with a BHR, the five-year estimated risk of revision
was 1.59%. In summary, after adjustment for a range of covariates we found
that there were significant differences in the rate of failure between
brands and component sizes. Younger male patients had good five-year
implant survival when the BHR was used.
We compared thromboembolic events, major haemorrhage
and death after total hip replacement in patients receiving either
aspirin or low-molecular-weight heparin (LMWH). We analysed data from
the National Joint Registry for England and Wales linked to an administrative
database of hospital admissions in the English National Health Service.
A total of 108 584 patients operated on between April 2003 and September 2008
were included and followed up for 90 days. Multivariable risk modelling
and propensity score matching were used to estimate odds ratios
(OR) adjusted for baseline risk factors. An OR <
1 indicates
that rates are lower with LMWH than with aspirin. In all, 21.1%
of patients were prescribed aspirin and 78.9% LMWH. Without adjustment, we
found no statistically significant differences. The rate of pulmonary
embolism was 0.68% in both groups and 90-day mortality was 0.65%
with aspirin and 0.61% with LMWH (OR 0.93; 95% CI 0.77 to 1.11).
With risk adjustment, the difference in mortality increased (OR
0.84; 95% CI 0.69 to 1.01). With propensity score matching the mortality difference
increased even further to 0.65% with aspirin and 0.51% with LMWH
(OR 0.77; 95% CI 0.61 to 0.98). These results should be considered
when the conflicting recommendations of existing guidelines for
thromboprophylaxis after hip replacement are being addressed.
We investigated the capacity of patient warming
devices to disrupt the ultra-clean airflow system. We compared the effects
of two patient warming technologies, forced-air and conductive fabric,
on operating theatre ventilation during simulated hip replacement
and lumbar spinal procedures using a mannequin as a patient. Infection
data were reviewed to determine whether joint infection rates were
associated with the type of patient warming device that was used. Neutral-buoyancy detergent bubbles were released adjacent to
the mannequin’s head and at floor level to assess the movement of
non-sterile air into the clean airflow over the surgical site. During
simulated hip replacement, bubble counts over the surgical site
were greater for forced-air than for conductive fabric warming when
the anaesthesia/surgery drape was laid down (p = 0.010) and at half-height
(p <
0.001). For lumbar surgery, forced-air warming generated
convection currents that mobilised floor air into the surgical site
area. Conductive fabric warming had no such effect. A significant increase in deep joint infection, as demonstrated
by an elevated infection odds ratio (3.8, p = 0.024), was identified
during a period when forced-air warming was used compared to a period
when conductive fabric warming was used. Air-free warming is, therefore,
recommended over forced-air warming for orthopaedic procedures.
Arthroscopy of the knee is one of the most commonly
performed orthopaedic procedures worldwide. Large-volume outcome
data have not previously been available for English NHS patients.
Prospectively collected admissions data, routinely collected on
every English NHS patient, were analysed to determine the rates
of complications within 30 days (including re-operation and re-admission),
90-day symptomatic venous thromboembolism and all-cause mortality.
There were 301 701 operations performed between 2005 and 2010 –
an annual incidence of 9.9 per 10 000 English population. Of these,
16 552 (6%) underwent ligament reconstruction and 106 793 (35%)
underwent meniscal surgery. The 30-day re-admission rate was 0.64%
(1662) and 30-day wound complication rate was 0.26% (677). The overall
30-day re-operation rate was 0.40% (1033) and the 90-day pulmonary embolism
rate was 0.08% (230), of which six patients died. 90-day mortality
was 0.02% (47). Age <
40 years, male gender and ligament reconstruction
were significantly associated with an increased rate of 30-day re-admission
and unplanned re-operation. In addition, a significant increase
in 30-day admission rates were seen with Charlson comorbidity scores
of 1 (p = 0.037) and ≥ 2 (p <
0.001) compared with scores of
0, and medium volume units compared with high volume units (p <
0.001). Complications following arthroscopy of the knee are rare. It
is a safe procedure, which in the majority of cases is performed
as day case surgery. These data can be used for quality benchmarking,
in terms of consent, consultant re-validation and individual unit
performance.
Increased femoral head size may reduce dislocation rates following total hip replacement. The National Joint Registry for England and Wales has highlighted a statistically significant increase in the use of femoral heads ≥ 36 mm in diameter from 5% in 2005 to 26% in 2009, together with an increase in the use of the posterior approach. The aim of this study was to determine whether rates of dislocation have fallen over the same period. National data for England for 247 546 procedures were analysed in order to determine trends in the rate of dislocation at three, six, 12 and 18 months after operation during this time. The 18-month revision rates were also examined. Between 2005 and 2009 there were significant decreases in cumulative dislocations at three months (1.12% to 0.86%), six months (1.25% to 0.96%) and 12 months (1.42% to 1.11%) (all p <
0.001), and at 18 months (1.56% to 1.31%) for the period 2005 to 2008 (p <
0.001). The 18-month revision rates did not significantly change during the study period (1.26% to 1.39%, odds ratio 1.10 (95% confidence interval 0.98 to 1.24), p = 0.118). There was no evidence of changes in the coding of dislocations during this time. These data have revealed a significant reduction in dislocations associated with the use of large femoral head sizes, with no change in the 18-month revision rate.
Diagnostic and operative codes are routinely collected for every patient admitted to hospital in the English NHS. Data on post-operative complications following foot and ankle surgery have not previously been available in large numbers. Data on symptomatic venous thromboembolism events and mortality within 90 days were extracted for patients undergoing fixation of an ankle fracture, first metatarsal osteotomy, hindfoot fusions and total ankle replacement over a period of 42 months. For ankle fracture surgery (45 949 patients), the rates of deep-vein thrombosis (DVT), pulmonary embolism and mortality were 0.12%, 0.17% and 0.37%, respectively. For first metatarsal osteotomy (33 626 patients), DVT, pulmonary embolism and mortality rates were 0.01%, 0.02% and 0.04%, and for hindfoot fusions (7033 patients) the rates were 0.03%, 0.11% and 0.11%, respectively. The rate of pulmonary embolism in 1633 total ankle replacement patients was 0.06%, and there were no recorded DVTs and no deaths. Statistical analysis could only identify risk factors for venous thromboembolic events of increasing age and multiple comorbidities following fracture surgery. Venous thromboembolism following foot and ankle surgery is extremely rare, but this subset of fracture patients is at a higher risk. However, there is no evidence that thromboprophylaxis reduces this risk, and these national data suggest that prophylaxis is not required in most of these patients.
Rivaroxaban has been recommended for routine use as a thromboprophylactic agent in patients undergoing lower-limb arthroplasty. However, trials supporting its use have not fully evaluated the risks of wound complications. This study of 1048 total hip/knee replacements records the rates of return to theatre and infection before and after the change from a low molecular weight heparin (tinzaparin) to rivaroxaban as the agent of chemical thromboprophylaxis in patients undergoing lower-limb arthroplasty. During a period of 13 months, 489 consecutive patients undergoing lower-limb arthroplasty received tinzaparin and the next 559 consecutive patients received rivaroxaban as thromboprophylaxis. Nine patients in the control (tinzaparin) group (1.8%, 95% confidence interval 0.9 to 3.5) returned to theatre with wound complications within 30 days, compared with 22 patients in the rivaroxaban group (3.94%, 95% confidence interval 2.6 to 5.9). This increase was statistically significant (p = 0.046). The proportion of patients who returned to theatre and became infected remained similar (p = 0.10). Our study demonstrates the need for further randomised controlled clinical trials to be conducted to assess the safety and efficacy of rivaroxaban in clinical practice, focusing on the surgical complications as well as the potential prevention of venous thromboembolism.
The National Institute for Clinical Excellence (NICE) produces recommendations on appropriate treatment within the National Health Service (NHS) in England and Wales. The NICE guidelines on prophylaxis for venous thromboembolism in orthopaedic surgery recommend that all patients be offered a low molecular weight heparin (LMWH). The linked hospital episode statistics of 219 602 patients were examined to determine the rates of complications following lower limb arthroplasty for the 12-month periods prior to and following the publication of these guidelines. These were compared with data from the National Joint Registry (England and Wales) regarding the use of LMWH during the same periods. There was a significant increase in the reported use of LMWH (59.5% to 67.6%, p <
0.001) following the publication of the guidelines. However, the 90-day venous thromboembolism events actually increased slightly following total hip replacement (THR, 1.69% to 1.84%, p = 0.06) and remained unchanged following total knee replacement (TKR, 1.99% to 2.04%). Return to theatre in the first 30 days for infection did not show significant changes. There was an increase in the number of patients diagnosed with thrombocytopenia, which was significant following THR (0.11% to 0.16%, p = 0.04). The recommendations from NICE are based on predicted reductions in venous thromboembolism events, reducing morbidity, mortality and costs to the NHS. The early results in orthopaedic patients do not support these predictions, but do show an increase in complications.
This paper considers the new financial infrastructure of the National Health Service and provides a resource for orthopaedic surgeons. We describe the importance of accurate documentation and data collection for National Health Service hospital Trust finances and league tables, and support our discussion with examples drawn from our local audit work.
We undertook a prospective, randomised study of 135 total knee arthroplasties to determine the most accurate and reliable technique for alignment of the tibial prosthesis. Tibial resection was guided by either intramedullary or extramedullary alignment jigs. Of the 135 knees, standardised postoperative radiographs suitable for assessment were available in 100. Correct tibial alignment was found in 85% of the intramedullary group compared with 65% of the extramedullary group (p = 0.019). We conclude that intramedullary guides are superior to extramedullary instruments for alignment of the tibial prosthesis.