Introduction of a New Protocol to Limit the Number of Cancelled Elective Orthopaedic Operations Due to Asymptomatic Bacteriuria.

Background Asymptomatic bacteriuria (ASB) poses a significant diagnostic dilemma for medical professionals. Current hospital screening protocol determines the likelihood of a positive diagnosis of a urinary tract infection (UTI) based on the results of a bedside urinalysis. ASB, defined as a positive urine culture in the absence of symptoms, can contribute to unnecessary cancellations, poor utilisation of theatre time, and delayed patient care. We present a two-cycle audit proposing a new pathway to addressing ASB in patients awaiting elective orthopaedic surgery, aiming to optimise surgical yield. Our objectives are to identify areas for improvement in our departmental practices with respect to asymptomatic bacteria compared to the published literature. We propose a new protocol targeted to improve our current practices to minimise patient cancellations and optimise theatre utilisation. Methodology A total of 78 patients who had an elective orthopaedic procedure cancelled at a large district general hospital offering tertiary orthopaedic services, between two study periods spanning March 2018 to April 2019 and May 2019 to March 2020, were identified from electronic hospital records and theatre management systems. Demographics, procedure details, and reasons for cancellations, including the result of urinalysis and the presence of UTI symptoms were assessed. Our pathway was introduced after the first study period and, subsequently, re-audited to assess adherence to the new protocol and its effect on cancellations. Results We identified 78 patients, with a 50:50 male:female split and an average age of 63 (range = 9-90). Of the 33 patients in the first cohort, seven (21.2%) were cancelled due to UTI risk based on positive urinalysis. Of these seven cancellations, one (14.3%) patient reported symptoms of a UTI. The second cohort comprised 45 patients, two (4.4%) of whom were cancelled due to UTI risk based on symptom questionnaire results. These two symptomatic patients along with another two asymptomatic patients (8.8% in total) were found to have positive urinalyses; however, the two asymptomatic patients had their operations cancelled for unrelated reasons. Conclusions The study has shown that previously of all patients awaiting elective orthopaedic operations who had their procedures cancelled, 85.7% were cancelled due to ASB. After the introduction of a new protocol focussing on symptoms rather than urinalysis, we estimate that the number of cancelled elective orthopaedic operations has reduced by 71.4%, thereby greatly improving the utilisation of theatre time.

Late Dislocations After Total Hip Arthroplasty: Is the Bearing a Factor?

BACKGROUND: Dislocation is a leading cause of revision after primary total hip arthroplasty (THA). Although more common in the first few years after the procedure, dislocation can occur at any time. This study investigated the difference in late dislocation in ceramic-on-ceramic (CoC) bearings compared with metal-on-polyethylene and ceramic-on-polyethylene bearings in THA. METHODS: Data were used from the Australian Orthopaedic Association National Joint Replacement Registry, and the cumulative percent revision for dislocation was estimated using the Kaplan-Meier method for the different bearing surfaces. There were 192,275 THAs included in the study with 101,915 metal-on-cross-linked polyethylene (MoXLPE), 30,256 ceramic-on-cross-linked polyethylene (CoXLPE), and 60,104 CoC. RESULTS: The cumulative percent revision for dislocation at 13 years for MoXLPE, CoXLPE, and CoC groups was 1.2 (95% confidence interval [CI], 1.1-1.3), 1.0 (95% CI, 0.7-1.4), and 0.9 (95% CI, 0.8-1.1), respectively. There was an increased risk of revision for dislocation for MoXLPE compared with CoXLPE and CoC. When stratified for head size, there was no difference in the risk of revision for dislocation between MoXLPE, CoXLPE, and CoC in the 28- and 32-mm head sizes. With a head size of 36 mm, MoXLPE had a higher rate of dislocation compared with other materials. CONCLUSION: Bearing surface has little impact on revision for dislocation.

Two-year serum metal ion levels in minimally invasive total conservative hip resurfacing: preliminary results of a prospective study.

BACKGROUND: Metal-on-metal (MoM) hip resurfacings have been associated with the potential development of metallic debris and its associated pathology. Serum cobalt and chromium levels are a reliable surrogate marker of wear rates in MoM bearings. The aim of the study was to examine the trend in serum metal ion levels in the initial 2-year post-operative period following implantation of the minimally invasive total conservative hip MoM hip resurfacing and to determine whether head size, acetabular component orientation, clinical outcome scores or post-operative range of movement would affect these levels. METHODS: In this prospective cohort study, serum cobalt and chromium ion levels were measured pre- and post-operatively in 25 patients who underwent minimally invasive total conservative hip MoM hip resurfacing. The results were correlated with acetabular component orientation, head size, outcome scores and post-operative range of movement. RESULTS: The mean serum cobalt and chromium levels at 2 years were 1.2 ppb (0.4-4.4 ppb) and 2.1 ppb (0.7-5.7 ppb). The mean cup inclination was 43° (30°-60°) and anteversion was 18° (1°-47°). There was no clear relationship between serum ions and acetabular component orientation, outcome scores or range of movement. Patients with a head size ≤52 mm had significantly higher metal ion levels (cobalt P = 0.02, chromium P = 0.045). CONCLUSION: Our preliminary results show all patients had cobalt and chromium levels below those indicating a high-risk implant, suggesting successful early outcome from minimally invasive total conservative hip resurfacing surgery.

Squeaking in large diameter ceramic-on-ceramic bearings in total hip arthroplasty.

We analyzed the results of 206 consecutive total hip arthroplasties performed using large diameter ceramic-on-ceramic bearings. At an average follow-up of 28months, the mean Harris Hip Score improved from 54 to 92. Fifteen (7.3%) hips were noted to squeak. There was no significant difference between silent and squeaking hips with regards to age, weight, height, BMI, range of movement, femoral head diameter, leg length, and offset or center of rotation. No correlation was present between incidence of squeaking and increasing cup inclination and anteversion. 5.2% of cups orientated within Lewinnek's safe zone squeaked. No hips required revision for squeaking. While large diameter ceramic bearings may produce squeaking, our early results of surgery using large head ceramic bearings are encouraging. However, long-term follow-up is required.

The effect of obesity on the clinical, functional and radiological outcome of cementless total hip replacement: a case-matched study with a minimum 10-year follow-up.

1420 primary cementless THRs with a minimum follow-up of 10-years were stratified according to BMI: non-obese (BMI<30kg/m(2)) and obese (BMI≥30kg/m(2)). Median age at surgery was younger in obese patients (P<0.001). We case-matched 82 THRs in obese patients with 162 THRs in non-obese patients. No difference between groups was found in improvement in HHS (P=0.668), satisfaction with surgery (P=0.644), range of movement, prosthesis orientation, or radiological loosening. The obese cohort was further separated into those with a BMI below and above 35. No difference was found between groups in improvement in HHS, satisfaction with surgery, component orientation, or radiological loosening. There was no difference in the incidence of post-operative complications between obese and non-obese patients. After 10-years, the results of THR are not compromised by obesity.

Photoacoustic thermography of tissue.

Photoacoustic (PA) techniques can measure temperature in biological tissues because PA signal amplitude is sensitive to tissue temperature. So far, temperature-measuring PA techniques have focused on sensing of temperature changes at a single position. In this work, we photoacoustically measured spatial distribution of temperature in deep tissue. By monitoring the temperature at a single position using a thermocouple, the relationship between the PA signal amplitude and the actual temperature was determined. The relationship was then used to translate a PA image into a temperature map. This study showed that it is possible to calibrate the system for the temperature range of hyperthermia using single-point measurements over a smaller temperature range. Our experimental results showed a precision of -0.8±0.4°C (mean±standard error) in temperature measurement, and a spatial resolution as fine as 1.0 mm. PA techniques can be potentially applied to monitor temperature distribution deep in tissue during hyperthermia treatment of cancer.

Cementless hip arthroplasty in Paget's disease at long-term follow-up (average of 12.3 years).

We present a long-term follow-up report of 33 cementless total hip arthroplasties in 27 patients who have an established diagnosis of Paget's disease. The medium term results of this series were reported in 2007 (Lusty et al. Journal of Arthroplasty. 2007;22:692). Fourteen cases were available for follow-up at an average of 12.3 years (range 10-17). Harris Hip scores improved from 56/100 preoperatively (16-98/100) to 83/100 post operatively (72-90/100). All surviving components were radiographically ingrown. Based on these findings, cementless total hip arthroplasty has a good long-term outcome in Paget's disease.

Absolute photoacoustic thermometry in deep tissue.

Photoacoustic thermography is a promising tool for temperature measurement in deep tissue. Here we propose an absolute temperature measurement method based on the dual temperature dependences of the Grüneisen parameter and the speed of sound in tissue. By taking ratiometric measurements at two adjacent temperatures, we can eliminate the factors that are temperature irrelevant but difficult to correct for in deep tissue. To validate our method, absolute temperatures of blood-filled tubes embedded ~9 mm deep in chicken tissue were measured in a biologically relevant range from 28°C to 46°C. The temperature measurement accuracy was ~0.6°C. The results suggest that our method can be potentially used for absolute temperature monitoring in deep tissue during thermotherapy.

Angioedema: a review of 367 episodes presenting to three tertiary care hospitals.

OBJECTIVES: We evaluated the clinical characteristics of patients treated for angioedema, and determined the factors associated with the clinical course. METHODS: We performed a chart review of 367 episodes presenting from 1997 through 2008. RESULTS: The mean (+/-SD) age was 51.8 +/- 20.1 years; 65.7% of the episodes occurred in female patients; 62.4% of the episodes were in African American patients. The patients were on angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) for 49.1% of the episodes, and an inciting factor (diet change, minor trauma, or exposure to fumes) was present for 21.5%. We found that 75.7% of the episodes were type 1 angioedema, 5.7% were type 2, 1.4% were type 3, and 17.2% involved multiple sites; 58% of the episodes required admission. For 3.3% of the episodes, the patients were intubated, and in 0.3% of the episodes, the patients required a tracheostomy. Logistic regression identified non-African American race, allergies, alcohol use, use of ACE inhibitors or ARBs, multiple sites, and age as associated with the need for admission. Bivariate analysis identified age, multiple affected sites, stridor, hoarseness, dysphagia, and drooling as associated with intubation or tracheostomy. CONCLUSIONS: The novel findings of this study are lower rates of airway intervention than reported previously and the fact that multiple affected sites were associated with admission and intubation or tracheostomy, particularly when the edema involved the larynx or hypopharynx.

Clinical vignette-based surveys: a tool for assessing physician practice variation.

Clinical vignette-based surveys have been used for more than 30 years to measure variation in physicians' approaches to the diagnosis and treatment of patients with similar health problems. Vignettes offer advantages over medical record reviews, analysis of claims data, and standardized patients. A vignette-based survey can be completed more quickly than a record review or standardized patient program. Research has shown that vignette-based surveys produce better measures of quality of care than medical record reviews when used to measure differential diagnosis, selection of tests, and treatment decisions. Although standardized patients are preferred when measuring communication and physical examination skills, vignettes are more cost-effective than standardized patients when assessing clinical physicians' decision making. Vignettes offer better opportunities to isolate physicians' decision making and to control case-mix variation than do analyses of claims data sets. Clinical vignette-based surveys are simple and economical tools that can be used to characterize physicians' practice variation.