The aim of our study was to describe the characteristics,
treatment, and outcomes of patients with periprosthetic joint infection
(PJI) and normal inflammatory markers after total knee arthroplasty
(TKA) and total hip arthroplasty (THA). In total 538 TKAs and 414 THAs underwent surgical treatment for
PJI and met the inclusion criteria. Pre-operative erythrocyte sedimentation
rate (ESR) and C-reactive protein level (CRP) were reviewed to identify
the seronegative cohort. An age- and gender-matched cohort was identified
from the remaining patients for comparison. Overall, 4% of confirmed
infections were seronegative (21 TKA and 17 THA). Of those who underwent
pre-operative aspiration, cultures were positive in 76% of TKAs
(n = 13) and 64% of THAs (n = 7). Cell count and differential were
suggestive of infection in 85% of TKA (n = 11) and all THA aspirates
(n = 5). The most common organism was coagulase-negative Cite this article:
The Control of Infection Committee at a specialist orthopaedic hospital prospectively collected data on all episodes of bacteriologically-proven deep infection arising after primary hip and knee replacements over a 15-year period from 1987 to 2001. There were 10 735 patients who underwent primary hip or knee replacement. In 34 of 5947 hip replacements (0.57%) and 41 of 4788 knee replacements (0.86%) a deep infection developed. The most common infecting micro-organism was coagulase-negative staphylococcus, followed by Of the infections, 29% (22) arose in the first three months following surgery, 35% between three months and one year (26), and 36% (27) after one year. Most cases were detected early and treated aggressively, with eradication of the infection in 96% (72). There was no significant change in the infection rate or type of infecting micro-organism over the course of this study. These results set a benchmark, and importantly emphasise that only 64% of peri-prosthetic infections arise within one year of surgery. These results also illustrate the advantages of conducting joint replacement surgery in the isolation of a specialist hospital.
We conducted a case-control study to examine
the merit of silver-coated tumour prostheses. We reviewed 85 patients
with Agluna-treated (silver-coated) tumour implants treated between
2006 and 2011 and matched them with 85 control patients treated
between 2001 and 2011 with identical, but uncoated, tumour prostheses. In all, 106 men and 64 women with a mean age of 42.2 years (18.4
to 90.4) were included in the study. There were 50 primary reconstructions
(29.4%); 79 one-stage revisions (46.5%) and 41 two-stage revisions
for infection (24.1%). The overall post-operative infection rate of the silver-coated
group was 11.8% compared with 22.4% for the control group (p = 0.033,
chi-square test). A total of seven of the ten infected prostheses
in the silver-coated group were treated successfully with debridement,
antibiotics, and implant retention compared with only six of the
19 patients (31.6%) in the control group (p = 0.048, chi-square
test). Three patients in the silver-coated group (3.5%) and 13 controls
(15.3%) had chronic periprosthetic infection (p = 0.009, chi-square
test). The overall success rates in controlling infection by two-stage
revision in the silver-coated group was 85% (17/20) compared with
57.1% (12/21) in the control group (p = 0.05, chi-square test).
The Agluna-treated endoprostheses were associated with a lower rate
of early periprosthetic infection. These silver-treated implants
were particularly useful in two-stage revisions for infection and
in those patients with incidental positive cultures at the time
of implantation of the prosthesis. Debridement with antibiotic treatment and retention of the implant
appeared to be more successful with silver-coated implants. Cite this article:
Between September 2004 and December 2005 we carried out a prospective study of all cases of sepsis of the hip in childhood at a South African regional hospital with a large local population, and which also took referrals from nine rural hospitals. The clinical, radiological, ultrasound and bacteriological features were assessed. All the hips were drained by arthrotomy and the diagnosis was confirmed microbiologically and histologically. Hips with tuberculosis were excluded. The children were reviewed in a dedicated clinic at a mean follow-up of 8.1 months (3 to 18). There were 40 hips with sepsis in 38 patients. Two patients were lost to follow-up. Nine (24%) had multi-focal sepsis. Overall, 13 hips (34%) had a full and uncomplicated clinical and radiological recovery and 25 (66%) had complications. All patients treated by arthrotomy and appropriate antibiotics within five days of the onset of symptoms had an uncomplicated recovery. Initial misdiagnosis was associated with a delay to arthrotomy. However, ‘deprivation’, consultation with a traditional healer, maternal educational attainment and distance to a primary health-care facility were not associated with delay to arthrotomy. The early correct diagnosis of this condition, common in the developing world, remains a significant factor in improving the clinical outcome.
Implant-associated infection is a major source
of morbidity in orthopaedic surgery. There has been extensive research
into the development of materials that prevent biofilm formation,
and hence, reduce the risk of infection. Silver nanoparticle technology
is receiving much interest in the field of orthopaedics for its
antimicrobial properties, and the results of studies to date are
encouraging. Antimicrobial effects have been seen when silver nanoparticles are
used in trauma implants, tumour prostheses, bone cement, and also
when combined with hydroxyapatite coatings. Although there are promising
results with Cite this article:
Conventional cemented acetabular components are
reported to have a high rate of failure when implanted into previously
irradiated bone. We recommend the use of a cemented reconstruction
with the addition of an acetabular reinforcement cross to improve
fixation. We reviewed a cohort of 45 patients (49 hips) who had undergone
irradiation of the pelvis and a cemented total hip arthroplasty
(THA) with an acetabular reinforcement cross. All hips had received
a minimum dose of 30 Gray (Gy) to treat a primary nearby tumour
or metastasis. The median dose of radiation was 50 Gy (Q1 to Q3:
45 to 60; mean: 49.57, 32 to 72). The mean follow-up after THA was 51 months (17 to 137). The cumulative
probability of revision of the acetabular component for a mechanical
reason was 0% (0 to 0%) at 24 months, 2.9% (0.2 to 13.3%) at 60
months and 2.9% (0.2% to 13.3%) at 120 months, respectively. One
hip was revised for mechanical failure and three for infection. Cemented acetabular components with a reinforcement cross provide
good medium-term fixation after pelvic irradiation. These patients
are at a higher risk of developing infection of their THA. Cite this article:
The treatment of infected nonunions is difficult.
Antibiotic cement-coated (ACC) rods provide stability as well as delivering
antibiotics. We conducted a review of 110 infected nonunions treated
with ACC rods. Patients were divided into two groups: group A (67
patients) with an infected arthrodesis, and group B (43 patients)
with an infected nonunion in a long bone. In group A, infected arthrodesis,
the success rate after the first procedure was 38/67 (57%), 29/67
(43%) required further surgery for either control of infection or
non-union. At last follow-up, five patients required amputation,
representing a limb salvage rate of 62/67 (93%) overall. In all,
29/67 (43%) presented with a bone defect with a mean size of 6.78
cm (2 to 25). Of those with a bone defect, 13/29 (45%) required
further surgery and had a mean size of defect of 7.2 cm (3.5 to
25). The cultures were negative in 17/67 (26%) and the most common
organism cultured was methicillin-resistant Cite this article:
A total of 31 patients, (20 women, 11 men; mean
age 62.5 years old; 23 to 81), who underwent conversion of a Girdlestone
resection-arthroplasty (RA) to a total hip replacement (THR) were
compared with 93 patients, (60 women, 33 men; mean age 63.4 years
old; 20 to 89), who had revision THR surgery for aseptic loosening
in a retrospective matched case-control study. Age, gender and the
extent of the pre-operative bone defect were similar in all patients.
Mean follow-up was 9.3 years (5 to 18). Pre-operative function and range of movement were better in the
control group (p = 0.01 and 0.003, respectively) and pre-operative
leg length discrepancy (LLD) was greater in the RA group (p <
0.001). The post-operative clinical outcome was similar in both
groups except for mean post-operative LLD, which was greater in
the study group (p = 0.003). There was a significant interaction
effect for LLD in the study group (p <
0.001). A two-way analysis
of variance showed that clinical outcome depended on patient age
(patients older than 70 years old had worse pre-operative pain,
p = 0.017) or bone defect (patients with a large acetabular bone
defect had higher LLD, p = 0.006, worse post-operative function
p = 0.009 and range of movement, p = 0.005), irrespective of the
group. Despite major acetabular and femoral bone defects requiring complex
surgical reconstruction techniques, THR after RA shows a clinical
outcome similar to those obtained in aseptic revision surgery for
hips with similar sized bone defects. Cite this article:
The December 2013 Research Roundup360 looks at: Inflammation implicated in FAI; Ponseti and effective teaching; Unicompartmental knee design and tibial strain; Bisphosphonates and fracture healing; Antibiosis in cement; Zoledronic acid improves primary stability in revision?; Osteoporotic fractures revisited; and electroarthrography for monitoring of cartilage degeneration
The rate of peri-prosthetic infection following
total joint replacement continues to rise, and attempts to curb
this trend have included the use of antibiotic-loaded bone cement
at the time of primary surgery. We have investigated the clinical-
and cost-effectiveness of the use of antibiotic-loaded cement for
primary total knee replacement (TKR) by comparing the rate of infection
in 3048 TKRs performed without loaded cement over a three-year period The absolute rate of infection increased when antibiotic-loaded
cement was used in TKR. However, this rate of increase was less
than the rate of increase in infection following uncemented THR
during the same period. If the rise in the rate of infection observed
in THR were extrapolated to the TKR cohort, 18 additional cases
of infection would have been expected to occur in the cohort receiving
antibiotic-loaded cement, compared with the number observed. Depending
on the type of antibiotic-loaded cement that is used, its cost in
all primary TKRs ranges between USD $2112.72 and USD $112 606.67
per case of infection that is prevented. Cite this article:
A soft-tissue defect over an infected total knee
replacement (TKR) presents a difficult technical problem that can
be treated with a gastrocnemius flap, which is rotated over the
defect during the first-stage of a revision procedure. This facilitates
wound healing and the safe introduction of a prosthesis at the second
stage. We describe the outcome at a mean follow-up of 4.5 years
(1 to 10) in 24 patients with an infected TKR who underwent this procedure.
A total of 22 (92%) eventually obtained a satisfactory result. The
mean Knee Society score improved from 53 pre-operatively to 103
at the latest follow-up (p <
0.001). The mean Western Ontario
and McMaster Universities osteoarthritis index and Short-Form 12
score also improved significantly (p <
0.001). This form of treatment can be used reliably and safely to treat
many of these complex cases where control of infection, retention
of the components and acceptable functional recovery are the primary
goals. Cite this article:
Cut-off values with highest sensitivity and specificity
for the synovial fluid white cell and differential count will facilitate
the accurate diagnosis of infection in total knee (TKR) and total
hip replacement (THR). All patients undergoing revision TKR or THR
for suspected prosthetic joint infection between 2009 and 2011 at
two hospitals were identified. A total of 75 patients were included
with a mean age of 70.3 years (38 to 89). Synovial fluid was aspirated
pre-operatively and peri-prosthetic tissue samples were taken intra-operatively
for histological and microbiological examination. Receiver operating characteristic (ROC) plots were constructed
for white cell and differential counts in aspirated fluid. The optimal
cut-off for TKR and THR was 1590 white cells/µl and 65% neutrophilia.
The white cell count cut-off value identified for THR was notably
lower than previously quoted in the literature. A cut-off value
for white cell count in synovial aspirate in suspected prosthetic
joint infection of between 1100 and 1700 white cells/µl is likely
to be applicable to both THR and TKR. Cite this article:
There have been few reports regarding the efficacy
of posterior instrumentation alone as surgical treatment for patients
with pyogenic spondylitis, thus avoiding the morbidity of anterior
surgery. We report the clinical outcomes of six patients with pyogenic
spondylitis treated effectively with a single-stage posterior fusion
without anterior debridement at a mean follow-up of 2.8 years (2
to 5). Haematological data, including white cell count and level
of C-reactive protein, returned to normal in all patients at a mean
of 8.2 weeks (7 to 9) after the posterior fusion. Rigid bony fusion
between the infected vertebrae was observed in five patients at
a mean of 6.3 months (4.5 to 8) post-operatively, with the remaining
patient having partial union. Severe back pain was immediately reduced
following surgery and the activities of daily living showed a marked
improvement. Methicillin-resistant Single-stage posterior fusion may be effective in patients with
pyogenic spondylitis who have relatively minor bony destruction.
Patients with infected arthroplasties are normally
treated with a two-stage exchange procedure using polymethylmethacrylate
bone cement spacers impregnated with antibiotics. However, spacers
may act as a foreign body to which micro-organisms may adhere and
grow. In this study it was hypothesised that subclinical infection may
be diagnosed with sonication of the surface biofilm of the spacer.
The aims were to assess the presence of subclinical infection through
sonication of the spacer at the time of a second-stage procedure,
and to determine the relationship between subclinical infection
and the clinical outcome. Of 55 patients studied, 11 (20%) were
diagnosed with subclinical infection. At a mean follow-up of 12
months (interquartile range 6 to 18), clinical failure was found in
18 (32.7%) patients. Of the patients previously diagnosed with subclinical
infection, 63% (7 of 11) had failed compared with 25% (11 of 44)
of those without subclinical infection (odds ratio 5.25, 95% confidence
interval 1.29 to 21.4, p = 0.021). Sonication of the biofilm of
the surface of the spacer is useful in order to exclude subclinical infection
and therefore contributes to improving the outcome after two-stage
procedures.
The removal of all prosthetic material and a
two-stage revision procedure is the established standard management of
an infected total hip replacement (THR). However, the removal of
well-fixed femoral cement is time-consuming and can result in significant
loss of bone stock and femoral shaft perforation or fracture. We
report our results of two-stage revision THR for treating infection,
with retention of the original well-fixed femoral cement mantle
in 15 patients, who were treated between 1989 and 2002. Following
partial excision arthroplasty, patients received local and systemic
antibiotics and underwent reconstruction and re-implantation at
a second-stage procedure, when the infection had resolved. The mean follow-up of these 15 patients was 82 months (60 to
192). Two patients had positive microbiology at the second stage
and were treated with six weeks of appropriate antibiotics; one
of these developed recurrent infection requiring further revision.
Successful eradication of infection was achieved in the remaining
14 patients. We conclude that when two-stage revision is used for the treatment
of peri-prosthetic infection involving a THR, a well-fixed femoral
cement mantle can be safely left
We present a retrospective review of 167 patients aged 18 years and under who were treated for chronic haematogenous osteomyelitis at our elective orthopaedic hospital in Malawi over a period of four years. The median age at presentation was eight years (1 to 18). There were 239 hospital admissions for treatment during the period of the study. In 117 patients one admission was necessary, in 35 two, and in 15 more than two. A surgical strategy of infection control followed by reconstruction and stabilisation was employed, based on the Beit CURE radiological classification of chronic haematogenous osteomyelitis as a guide to treatment. At a minimum follow-up of one year after the end of the study none of the patients had returned to our hospital with recurrent infection. A total of 350 operations were performed on the 167 patients. This represented 6.7% of all children’s operations performed in our hospital during this period. One operation only was required in 110 patients and none required more than three. Below-knee amputation was performed in two patients with chronic calcaneal osteomyelitis as the best surgical option for function. The most common organism cultured from operative specimens was
A silver-containing hydroxyapatite (Ag-HA) coating has been developed using thermal spraying technology. We evaluated the osteoconductivity of this coating on titanium (Ti) implants in rat tibiae in relation to bacterial infection in joint replacement. At 12 weeks, the mean affinity indices of bone formation of a Ti, an HA, a 3%Ag-HA and a 50%Ag-HA coating were 97.3%, 84.9%, 81.0% and 40.5%, respectively. The mean affinity indices of bone contact of these four coatings were 18.8%, 83.7%, 77.2% and 40.5%, respectively. The indices of bone formation and bone contact around the implant of the 3%Ag-HA coating were similar to those of the HA coating, and no significant differences were found between them (bone formation, p = 0.99; bone contact, p = 0.957). However, inhibition of bone formation was observed with the 50%Ag-HA coating. These results indicate that the 3%Ag-HA coating has low toxicity and good osteoconductivity, and that the effect of silver toxicity on osteoconductivity depends on the dose.
Periprosthetic infection following total hip replacement can be a catastrophic complication for the patient. The treatments available include single-stage exchange, and two-stage exchange. We present a series of 50 consecutive patients with a diagnosis of infected total hip replacement who were assessed according to a standardised protocol. Of these, 11 underwent single-stage revision arthroplasty with no recurrence of infection at a mean of 6.8 years follow-up (5.5 to 8.8). The remaining 39 underwent two-stage revision, with two recurrences of infection successfully treated by a second two-stage procedure. At five years, significant differences were found in the mean Harris Hip Scores (single-stage 87.8; two-stage 75.5; p = 0.0003) and in a visual analogue score for satisfaction (8.6; 6.9; p = 0.001) between the single- and two-stage groups. Single-stage exchange is successful in eradicating periprosthetic infection and results in excellent functional and satisfaction scores. Identification of patients suitable for the single-stage procedure allows individualisation of care and provides as many as possible with the correct strategy in successfully tackling their periprosthetic infection
Osteoarthritis (OA) is an important cause of
pain, disability and economic loss in humans, and is similarly important in
the horse. Recent knowledge on post-traumatic OA has suggested opportunities
for early intervention, but it is difficult to identify the appropriate
time of these interventions. The horse provides two useful mechanisms
to answer these questions: 1) extensive experience with clinical
OA in horses; and 2) use of a consistently predictable model of
OA that can help study early pathobiological events, define targets
for therapeutic intervention and then test these putative therapies.
This paper summarises the syndromes of clinical OA in horses including
pathogenesis, diagnosis and treatment, and details controlled studies
of various treatment options using an equine model of clinical OA.