Intra-articular administration of antibiotics during primary total knee arthroplasty (TKA) may represent a safe, cost-effective strategy to reduce the risk of acute periprosthetic joint infection (PJI). Vancomycin with an aminoglycoside provides antimicrobial cover for most organisms isolated from acute PJI after TKA. However, the intra-articular doses required to achieve sustained therapeutic intra-articular levels while remaining below toxic serum levels is unknown. The purpose of this study is to determine the intra-articular and serum levels of vancomycin and tobramycin over the first 24 hours postoperatively after intra-articular administration in primary cementless TKA. A prospective cohort study was performed. Patients were excluded if they had poor renal function, known allergic reaction to vancomycin or tobramycin, received intravenous vancomycin, or were scheduled for same-day discharge. All patients received 600 mg tobramycin and 1 g of vancomycin powder suspended in 25 cc of normal saline and injected into the joint after closure of the arthrotomy. Serum from peripheral venous blood and drain fluid samples were collected at one, four, and 24 hours postoperatively. All concentrations are reported in µg per ml.Aims
Methods
The goal of the current systematic review was to assess the impact of implant placement accuracy on outcomes following total knee arthroplasty (TKA). A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the Ovid Medline, Embase, Cochrane Central, and Web of Science databases in order to assess the impact of the patient-reported outcomes measures (PROMs) and implant placement accuracy on outcomes following TKA. Studies assessing the impact of implant alignment, rotation, size, overhang, or condylar offset were included. Study quality was assessed, evidence was graded (one-star: no evidence, two-star: limited evidence, three-star: moderate evidence, four-star: strong evidence), and recommendations were made based on the available evidence.Aims
Methods
Dual mobility (DM) implants have been shown to reduce the dislocation rate after total hip arthroplasty (THA), but there remain concerns about the use of cobalt chrome liners inserted into titanium shells. The aim of this study was to assess the clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) at mid-term follow-up in young, active patients receiving a modular DM THA. This was a prospective study involving patients aged < 65 years, with a BMI of < 35 kg/m2, and University of California, Los Angeles activity score of > 6 who underwent primary THA with a modular cobalt chrome acetabular liner, highly cross-linked polyethylene mobile bearing, and a cementless titanium femoral stem. Patient-reported outcome measures, whole blood metal ion levels (μg/l), and periprosthetic femoral BMD were measured at baseline and at one, two, and five years postoperatively. The results two years postoperatively for this cohort have been previously reported.Aims
Methods
The purpose of this study was to determine the access to and ability to use telemedicine technology in adult patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), and to determine associations with the socioeconomic characteristics of the patients, including age, sex, race, and education. We also sought to understand the patients’ perceived benefits, risks, and preferences when dealing with telemedicine. We performed a cross-sectional survey involving patients awaiting primary THA and TKA by one of six surgeons at a single academic institution. Patients were included and called for a telephone-administered survey if their surgery was scheduled to be between 23 March and 2 June 2020, and were aged > 18 years.Aims
Methods
The purpose of this study was to compare the radiological outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA). Postoperative radiological outcomes from 86 consecutive robotic-assisted UKAs (RAUKA group) from a single academic centre were retrospectively reviewed and compared to 253 manual UKAs (MUKA group) drawn from a prior study at our institution. Femoral coronal and sagittal angles (FCA, FSA), tibial coronal and sagittal angles (TCA, TSA), and implant overhang were radiologically measured to identify outliers.Aims
Methods
Modular dual mobility (MDM) prostheses are increasingly utilized for total hip arthroplasty (THA) to mitigate the risk of postoperative instability in high risk patients. Short-term reports on clinical outcomes are favorable but there are few studies on young active patients. This study quantified proximal femoral stress shielding and metal ion release in MDM combined with modern cementless stem design in young active patients. This was a prospective study of patients between 18 and 65 years of age, with a body mass index (BMI) < 35 kg/m2 and University of California at Los Angeles (UCLA) activity score > 6, who received a modular cobalt-chromium acetabular liner, highly crosslinked polyethylene mobile bearing, and cementless titanium femoral stem for their primary THA. DEXA scans were performed at 6 weeks postoperatively as a baseline, then again at 6 months, 1 year, 2 years and 5 years postoperatively as were metal ions.Introduction
Methods
Bone mineral density (BMD) is correlated with component migration and aseptic loosening after total knee arthroplasty (TKA). Older implant designs have demonstrated BMD loss up to 23% in the first 6 months after TKA, and continued to BMD decline at an average of 5% per year for as long as 2 years after TKA. The impact of component design and fixation method on BMD loss after TKA in modern implant designs has not been fully elucidated. The purpose of this study is to determine the effect of tibial tray thickness and fixation method (cemented versus cementless) on BMD loss patterns of the proximal tibia in two different modern TKA implant systems A prospective, nonrandomized, single center study of patients undergoing primary TKA by one of two surgeons was performed with four study cohorts: cemented DePuy Attune, cementless DePuy Attune, cemented Stryker Triathlon, cementless Stryker Triathlon. Target sample size was 80, with 20 per cohort based on adhoc power analysis. Exclusion criteria included: age over 75, BMI >40, inflammatory arthritis, previous knee surgery involving the femur, tibia or tibial bone, and diagnosis of osteopenia/osteoporosis. Implant fixation type was based on surgeon intraoperative assessment of patient bone quality. Demographic data was collected preoperatively. Dual Energy X-ray Absorptiometry (DEXA) Bone Density Monitoring was performed at 6 weeks and one year postoperatively. Bone mineral density was calculated from the DEXA scans for 4 zones for the tibia relative to the keel or central peg: anterior, posterior, medial and lateral. Results were reported as BMD at 1 year postoperatively as a percentage of BMD at 6 weeks postoperatively.Introduction
Methods
The purpose of the study was to determine access to and, ability to use telemedicine technology in an adult hip and knee reconstruction patient population and we seek to understand these patients' perceived benefits, risks and preferences of telemedicine. We performed a cross-sectional telephone administered survey on patients scheduled to undergo primary THA and TKA by one of six surgeons at a single academic institution between March 23 and June 2, 2020.Introduction
Methods
The purpose of this study was to compare the radiographic outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA). Postoperative radiographic outcomes from 86 consecutive robotic-assisted UKAs (RAUKA group) from a single academic center were retrospectively reviewed and compared to 253 manual UKAs (MUKA group) drawn from a prior study at our institution. Femoral coronal and sagittal angles (FCA, FSA), tibial coronal and sagittal angles (TCA, TSA), and implant overhang were radiographically measured to identify outliers. Clinical results at 4–6 weeks postoperative were compared to a control cohort of total knee arthroplasty (TKA) patients from our institution.Introduction
Materials & Methods
The aims of this study were to determine the change in the sagittal alignment of the pelvis and the associated impact on acetabular component position at one-year follow-up after total hip arthroplasty (THA). This study represents the one-year follow-up of a previous short-term study at our institution. Using the patient population from our prior study, the radiological pelvic ratio was assessed in 91 patients undergoing THA, of whom 50 were available for follow-up of at least one year (median 1.5; interquartile range (IQR) 1.1 to 2.0). Anteroposterior radiographs of the pelvis were obtained in the standing position preoperatively and at one year postoperatively. Pelvic ratio was defined as the ratio between the vertical distance from the inferior sacroiliac (SI) joints to the superior pubic symphysis and the horizontal distance between the inferior SI joints. Apparent acetabular component position changes were determined from the change in pelvic ratio. A change of at least 5° was considered clinically meaningful.Aims
Methods
The aim of this study was to determine if the local delivery of vancomycin and tobramycin in primary total knee arthroplasty (TKA) can achieve intra-articular concentrations exceeding the minimum inhibitory concentration thresholds for bacteria causing acute prosthetic joint infection (PJI). Using a retrospective single-institution database of all primary TKAs performed between January 1 2014 and May 7 2019, we identified patients with acute PJI that were managed surgically within 90 days of the initial procedure. The organisms from positive cultures obtained at the time of revision were tested for susceptibility to gentamicin, tobramycin, and vancomycin. A prospective study was then performed to determine the intra-articular antibiotic concentration on postoperative day one after primary TKA using one of five local antibiotic delivery strategies with tobramycin and/or vancomycin mixed into the polymethylmethacrylate (PMMA) or vancomycin powder.Aims
Methods
The purpose of this study was to assess the overall clinical and radiographic outcomes of unicompartmental knee arthroplasty (UKA) in the 2–10 year postoperative period. The secondary goal was to compare outcomes between fixed- (FB) and mobile-bearing (MB) implant designs. We performed a retrospective analysis of 237 consecutive primary medial UKAs from a single academic center. All cases were performed by high-volume fellowship-trained arthroplasty surgeons, though UKA comprised <10% of their overall knee arthroplasty practice (<20 medial UKAs per surgeon per year). Clinical outcomes included the Oxford Knee Scores (OKS) and revision rates. Femoral and tibial coronal and sagittal angles (FCA, FSA, TCA, TSA) were radiographically measured. FCA (>±10º deviation from the neutral axis), FSA (>15º flexion), TCA (>±5º deviation from the neutral axis), and TSA (>±5º deviation from 7º) outliers were defined. Far outliers were defined as measurements that fell an additional >±2º outside of these ranges. Outcomes were compared between the FB and MB groups.Background
Methods
Periprosthetic infection (PJI) after primary total knee arthroplasty (TKA) remains a challenging issue affecting 1–2% of cases. Locally delivered prophylactic antibiotics, including tobramycin or gentamicin mixed in polymethylmethacrylate (PMMA) bone cement and vancomycin powder, are increasingly used despite a lack of high quality evidence for either practice. In this study, we report the antibiotic susceptibility of organisms recovered in culture from patients with acute prosthetic joint infection after primary TKA to gentamicin, tobramycin and vancomycin. Using a retrospective database of all primary TKA performed at a single institution between January, 1 2014 and July 1, 2018, we identified 18 cases of acute PJI after primary TKA, as defined by the Musculoskeletal Infection Society 2011 guidelines as less than 3 months from symptoms or index surgery to presentation. The use of antibiotic bone cement during the index procedure and time to surgical management of the infection were recorded. Fluid cultures and tissue cultures were obtained intraoperatively at the time of revision. The organisms from positive cultures underwent MIC testing to gentamicin, tobramycin and vancomycin using a gradient diffusion method (ETEST). MIC breakpoints for susceptibility were based on Clinical and Laboratory Standards Institute definitions.Introduction
Methods
The utility and yield of the current practice of routine screening of asymptomatic patients after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) is unclear. The purpose of this prospective survey study was to determine the utility of the routine on year follow up visit primary THA and TKA. We prospectively enrolled all patients undergoing primary THA and TKA. At one-year follow-up, patients were asked to complete a survey that asked about satisfaction with the and if they thought the visit was worthwhile. Surgeons also completed a survey which asked if any intervention was done, if any problems were diagnosed/avoided, and if the visit was worthwhile. Data was analyzed and compared between patients and surgeons, and was also compared to the need for any additional interventionsIntroduction
Methods
The aim of this study was to determine the change in standing pelvic sagittal alignment and associated impact on functional acetabular component position at follow-up after total hip arthroplasty (THA). A retrospective review was performed on 91 consecutive patients who had undergone primary THA by a single surgeon via a posterior approach in the lateral decubitus position. Of these, 41 patients had high quality standing AP pelvis radiographs preoperatively, at six weeks postoperatively, and at one year postoperatively available for analysis. Pelvic ratio was defined as the ratio between the vertical distance from the inferior sacroiliac (SI) joints to the superior pubic symphysis and the horizontal distance between the inferior SI joints. Apparent changes in the functional acetabular component position were determined from the change in pelvic ratio between the preoperative and one year postoperative standing AP pelvic radiograph. A change of at least five degrees was considered clinically meaningful.Background
Patients and Methods
The aim of this study was to compare the actual cost of a cemented and cementless total knee arthroplasty (TKA) procedure. The cost of operative time, implants, cement, and cementing accessories were included in the overall cost of the TKA procedure. Operative time was determined from a previously published study comparing cemented and cementless implants of the same design. The cost of operative time, implants, cement, and cementing accessories was determined from market and institutional data.Aims
Materials and Methods
Whether patient-reported pain differs among surgical approaches in total hip arthroplasty (THA) remains unclear. This study’s purposes were to determine differences in pain based on surgical approach (direct anterior (DA) This was a retrospective investigation from two centres and seven surgeons (three DA, three PL, one both) of primary THAs. PL patients were categorized for incision length (6 cm to 8 cm, 8 cm to 12 cm, 12 cm to 15 cm). All patients had cementless femoral and acetabular fixation, at least one year’s follow-up, and well-fixed components. Patients completed a pain-drawing questionnaire identifying the location and intensity of pain on an anatomical diagram. Power analysis indicated 800 patients in each cohort for adequate power to detect a 4% difference in pain (alpha = 0.05, beta = 0.80).Aims
Patients and Methods
The aims of this study were to determine the change in pelvic sagittal alignment before, during, and after total hip arthroplasty (THA) undertaken with the patient in the lateral decubitus position, and to determine the impact of these changes on acetabular component position. We retrospectively compared the radiological pelvic ratio among 91 patients undergoing THA. In total, 41 patients (46%) were female. The mean age was 61.6 years (Aims
Patients and Methods
Modular dual mobility (DM) prostheses in which a cobalt-chromium liner is inserted into a titanium acetabular shell ( This was a prospective study of patients between 18 and 65 years of age, with a body mass index (BMI) < 35 kg/m2 and University of California at Los Angeles (UCLA) activity score > 6, who received a modular cobalt-chromium acetabular liner, highly crosslinked polyethylene mobile bearing, and cementless titanium femoral stem for their primary THA. Patients with a history of renal disease and metal hardware elsewhere in the body were excluded. A total of 43 patients (30 male, 13 female; mean age 52.6 years (Aims
Patients and Methods
Surface replacement arthroplasty (SRA), compared with traditional total hip arthroplasty (THA), is more expensive and carries unique concern related to metal ions production and hypersensitivity. Additionally, SRA is a more demanding procedure with a decreased margin for error compared with THA. To justify its use, SRA must demonstrate comparable component survival and some clinical advantages. We therefore performed a systematic literature review to investigate the differences in complication rates, patient-reported outcomes, stress shielding, and hip biomechanics between SRA and THA. A systematic review of the literature was completed using MEDLINE and EMBASE search engines. Inclusion criteria were level I to level III articles that reported clinical outcomes following primary SRA compared with THA. An initial search yielded 2503 potential articles for inclusion. Exclusion criteria included review articles, level IV or level V evidence, less than one year’s follow-up, and previously reported data. In total, 27 articles with 4182 patients were available to analyze.Aims
Materials and Methods
Cemented total knee arthroplasty (TKA) remains the gold standard with survivorship above 90% at greater than 10 years postoperatively. However, with younger, heavier, more active patients undergoing TKA at an increasing rate, cementless implants have the appeal of potential for improved implant fixation longevity and decreased rates of aseptic loosening. The cementless implants are more expensive than their cemented counterparts such that implant costs may create a barrier to utilization. However, such comparisons fail to consider the unavoidable additional costs of cementing, including the cost of operating room time, cement and cementing accessories. The purpose of this study is to compare the actual cost of cemented and cementless TKA. The TKA cost calculation included the cost of operative time, implants, cement and cementing accessories. The difference in operative time between cemented and cementless TKA was determined from a previously published study of 100 TKAs performed using a cemented (55) or press fit (45) implant of the same design performed at a single institution by four fellowship trained arthroplasty surgeons. The decision to use cemented or cementless design in these patients was made based on patient bone quality intraoperatively. Operative time was compared between groups using a Student's two-tailed T-test. The cost of operating room time was based on estimates in the recent literature. The cost of cement and cementing accessories was estimated based on publically available market data. The cost of implants was estimated from institutional data for multiple companies.Introduction
Methods
Implant malalignment is an important predictor of prosthetic failure following total knee arthroplasty (TKA). The purpose of this study was to determine the incidence of outliers for common alignment targets and the impact of surgeon volume and experience on the accuracy of implant alignment with current generation manual instrumentation. This study was a retrospective, multi-center, radiographic analysis of 1675 consecutive primary uncomplicated TKAs from seven surgeons at three academic and state-funded centers in the US and UK. Surgeons were categorized as “high-volume” (≥50 TKAs/year) and “high-experience” (≥5 years post-fellowship). Femorotibial, tibial varus/valgus, and posterior tibial slope angles were digitally measured using postoperative radiographs. Femorotibial (<2° or >8° valgus), tibial (> ±3° deviation from the neutral axis), and tibial slope (<0° or >7° of flexion for cruciate retaining, <0° or >5° of flexion for posterior stabilized) angle outliers were identified. The proportion of outliers among surgeons in each subgroup was compared.Introduction
Methods
Malposition of the acetabular component in total hip arthroplasty (THA) is linked to multiple adverse outcomes. Changes in the sagittal plane position of the pelvis, owing both to patient positioning in the operating room and to altered spinopelvic alignment following surgery, potentially contribute to variation in component position. The dynamics of sagittal plane pelvic position before, during, and after THA have not been defined. We measured the differences in pelvic ratio, a measure of sagittal plane pelvic position, between preoperative, intraoperative, and postoperative anteroposterior (AP) radiographs of patients undergoing THA in the lateral decubitus position. We retrospectively compared the radiographic pelvic ratio among 90 patients undergoing THA. AP radiographs were obtained in the standing position preoperatively and at 6 weeks after surgery; in the lateral decubitus position after trial reduction intraoperatively; and in the supine position in the post anesthesia care unit (PACU). Pelvic ratio was defined as the ratio between the vertical distance from the inferior sacroiliac (SI) joints to the superior pubic symphysis and the horizontal distance between the inferior SI joints. Radlink software was used to determine the pelvic ratio on each radiograph. Changes in apparent cup position based on changes in pelvic ratio were calculated using data from the literature, and a change of at least 10 degrees in acetabular component position was defined as clinically meaningful. Analyses were performed using paired t-tests, with p<0.05 defined as significant.Introduction
Methods
Despite well-fixed implants, persistent pain following total hip arthroplasty (THA) remains a concern. Various surgical approaches have been advocated, yet whether patient-reported pain differs amongst techniques has not been investigated. This study's purposes were to determine differences in patient-reported pain based on surgical approach (direct anterior –DA versus posterolateral-PL) or PL approach incision length. Our hypothesis was that no differences in patient-reported pain would be present. A retrospective, IRB-approved investigation from 2 centers was performed. 7 fellowship trained arthroplasty surgeons (3 DA, 3 PL, 1 both) enrolled patients undergoing primary THA for non-inflammatory arthritis. PL approach patients were categorized based on incision length (6–8cm, 8–12cm, 12–15cm). Exclusion criteria were a prior hip surgery, revision procedure, or limited postoperative mobility. All THAs were performed using a cementless titanium, proximally coated, tapered femoral stem and hemispherical acetabular component. All patients had a minimum of 1-year clinical follow-up with radiographically well-fixed components. A pain-drawing questionnaire was administered in which patients identify the location and intensity of pain on an anatomic diagram. Independent Student's t-tests and Chi-square analyses were performed (p<0.05 = significant). Power analysis indicated 800 patients in each cohort would provide adequate power to detect a 4% difference in patient-reported pain (alpha = 0.05, beta = 0.80).Introduction
Methods
The purpose of our study is to summarise the current scientific
findings regarding the impact of obesity on total hip arthroplasty
(THA); specifically the influence of obesity on the timing of THA,
incidence of complications, and effect on clinical and functional
outcomes. We performed a systematic review that was compliant with the
Preferred Reporting Items for Systematic Reviews and Meta-Analyses
guidelines to identify prospective studies from the PubMed/Medline,
Embase, and Cochrane Library databases that evaluated primary THA
in obese (body mass index (BMI) ≥ 30 kg/m2) patients.Aims
Materials and Methods
The purpose of this article was to review the current literature
pertaining to the use of mobile compression devices (MCDs) for venous
thromboembolism (VTE) following total joint arthroplasty (TJA),
and to discuss the results of data from our institution. Previous studies have illustrated higher rates of post-operative
wound complications, re-operation and re-admission with the use
of more aggressive anticoagulation regimens, such as warfarin and
factor Xa inhibitors. This highlights the importance of the safety,
as well as efficacy, of the chemoprophylactic regimen.Aims
Patients and Methods
The use of large-diameter metal-on-metal (MoM)
components in total hip arthroplasty (THA) is associated with an increased
risk of early failure due to adverse local tissue reaction to metal
debris (ARMD) in response to the release of metal ions from the
bearing couple and/or head-neck taper corrosion. The aim of this
paper was to present a review of the incidence and natural history
of ARMD and the forms of treatment, with a focus on the need for
and extent of resection or debulking of the pseudotumour. An illustrative
case report is presented of a patient with an intra-pelvic pseudotumour
associated with a large diameter MoM THA, which was treated successfully
with revision of the bearing surface to a dual mobility couple and
retention of the well-fixed acetabular and femoral components. The
pseudotumour was left Cite this article:
This study investigated whether the use of tranexamic acid (TXA)
decreased blood loss and transfusion related cost following surface
replacement arthroplasty (SRA). A retrospective review of patients treated with TXA during a
SRA, who did not receive autologous blood (TXA group) was performed.
Two comparison groups were established; the first group comprised
of patients who donated their own blood pre-operatively (auto group)
and the second of patients who did not donate blood pre-operatively
(control). Outcomes included transfusions, post-operative haemoglobin
(Hgb), complications, and length of post-operative stay. Aims
Methods
The aims of this retrospective study were to
compare the mid-term outcomes following revision total knee replacement
(TKR) in 76 patients (81 knees) <
55 years of age with those
of a matched group of primary TKRs based on age, BMI, gender and
comorbid conditions. We report the activity levels, functional scores,
rates of revision and complications. Compared with patients undergoing
primary TKR, those undergoing revision TKR had less improvement
in the mean Knee Society function scores (8.14 (–55 to +60) Young patients undergoing revision TKR should be counselled that
they can expect somewhat less improvement and a higher risk of complications
than occur after primary TKR. Cite this article:
A national, multi-centre study was designed in
which a questionnaire quantifying the degree of patient satisfaction
and residual symptoms in patients following total knee replacement
(TKR) was administered by an independent, blinded third party survey
centre. A total of 90% of patients reported satisfaction with the
overall functioning of their knee, but 66% felt their knee to be
‘normal’, with the reported incidence of residual symptoms and functional
problems ranging from 33% to 54%. Female patients and patients from
low-income households had increased odds of reporting dissatisfaction.
Neither the use of contemporary implant designs (gender-specific,
high-flex, rotating platform) or custom cutting guides (CCG) with
a neutral mechanical axis target improved patient-perceived outcomes.
However, use of a CCG to perform a so-called kinematically aligned
TKR showed a trend towards more patients reporting their knee to
feel ‘normal’ when compared with a so called mechanically aligned
TKR This data shows a degree of dissatisfaction and residual symptoms
following TKR, and that several recent modifications in implant
design and surgical technique have not improved the current situation. Cite this article:
Haematomas, drainage, and other non-infectious
wound complications following total knee replacement (TKR) have
been associated with long-term sequelae, in particular, deep infection.
However, the impact of these wound complications on clinical outcome
is unknown. This study compares results in 15 patients re-admitted
for wound complications within 90 days of TKR to 30 matched patients
who underwent uncomplicated total knee replacements. Patients with
wound complications had a mean age of 66 years (49 to 83) and mean
body mass index (BMI) of 37 (21 to 54), both similar to that of
patients without complications (mean age 65 years and mean BMI 35). Those
with complications had lower mean Knee Society function scores (46
(0 to 100 Cite this article:
Cementless femoral stems are currently preferred
for total hip replacement (THR) in the United States. Improvements
in stem design, instrumentation and surgical technique have made
this technology highly successful, reproducible, and applicable
to the vast majority of patients requiring a THR. However, there
are ongoing developments in some aspects of stem design that influence
clinical results, the incidence of complications and their inherent adaptability
in accommodating the needs of individual patients. Here we examine
some of these design features. Cite this article:
Patient specific cutting guides generated by
preoperative Magnetic Resonance Imaging (MRI) of the patient’s extremity
have been proposed as a method of improving the consistency of Total
Knee Arthroplasty (TKA) alignment and adding efficiency to the operative
procedure. The cost of this option was evaluated by quantifying the
savings from decreased operative time and instrument processing
costs compared to the additional cost of the MRI and the guide.
Coronal plane alignment was measured in an unselected consecutive
series of 200 TKAs, 100 with standard instrumentation and 100 with
custom cutting guides. While the cutting guides had significantly lower
total operative time and instrument processing time, the estimated
$322 savings was overwhelmed by the $1,500 additional cost of the
MRI and the cutting guide. All measures of coronal plane alignment
were equivalent between the two groups. The data does not currently
support the proposition that patient specific guides add value to
TKA.
Venous thromboembolism (VTE) remains an immediate
threat to patients following total hip and knee replacement. While
there is a strong consensus that steps should be taken to minimise
the risk to patients by utilising some forms of prophylaxis for
the vast majority of patients, the methods utilised have been extremely
variable. Clinical practice guidelines (CPGs) have been published
by various professional organisations for over 25 years to provide recommendations
to standardise VTE prophylaxis. Historically, these recommendations
have varied widely depending in underlying assumptions, goals, and
methodology of the various groups. This effort has previously been
exemplified by the American College of Chest Physicians (ACCP) and
the American Academy of Orthopaedic Surgeons (AAOS). The former
group of medical specialists targeted minimising venographically
proven deep vein thrombosis (DVT) (the vast majority of which are
asymptomatic) as their primary goal prior to 2012. The latter group of
surgeons targeted minimising symptomatic VTE. As a result prior
to 2012, the recommendations of the two groups were widely divergent.
In the past year, both groups have reassessed the current literature
with the principal goals of minimising symptomatic VTE events and
bleeding complications. As a result, for the first time the CPGs
of these two major subspecialty organisations are in close agreement.
Since 1996 more than one million metal-on-metal
articulations have been implanted worldwide. Adverse reactions to
metal debris are escalating. Here we present an algorithmic approach
to patient management. The general approach to all arthroplasty
patients returning for follow-up begins with a detailed history,
querying for pain, discomfort or compromise of function. Symptomatic
patients should be evaluated for intra-articular and extra-articular
causes of pain. In large head MoM arthroplasty, aseptic loosening
may be the source of pain and is frequently difficult to diagnose.
Sepsis should be ruled out as a source of pain. Plain radiographs
are evaluated to rule out loosening and osteolysis, and assess component
position. Laboratory evaluation commences with erythrocyte sedimentation
rate and C-reactive protein, which may be elevated. Serum metal
ions should be assessed by an approved facility. Aspiration, with
manual cell count and culture/sensitivity should be performed, with
cloudy to creamy fluid with predominance of monocytes often indicative
of failure. Imaging should include ultrasound or metal artifact
reduction sequence MRI, specifically evaluating for fluid collections
and/or masses about the hip. If adverse reaction to metal debris
is suspected then revision to metal or ceramic-on-polyethylene is indicated
and can be successful. Delay may be associated with extensive soft-tissue
damage and hence poor clinical outcome.
We reviewed 194 revision arthroplasties of the hip and knee performed over a ten-year period. The results of intraoperative Gram staining were available in 169 (87%). Thirty-two were found to be infected (11 hips and 21 knees) and 137 had no evidence of infection. Intraoperative Gram staining was negative in all 169 cases. The method therefore had a sensitivity of 0% for detecting infection. We conclude that the absence of organisms on intraoperative Gram staining during revision arthroplasty does not confirm the absence of infection.
