Local Validation of a National Orthopaedic Registry.

BACKGROUND/OBJECTIVE: Registries are limited by the quality of the data they collect. We aimed to measure the data entry error rate at a regional orthopaedic unit in a national arthroplasty registry and to assess a proposed intervention of restricting data entry to senior trainees. METHODS AND MATERIALS: A total of 200 primary and revision arthroplasty cases (119 hips, 81 knees) were randomly selected from a single year, 2020. The Irish National Orthopaedic Registry was examined for the grade of the trainee that populated the form and the accuracy of 24 parameters by comparison with data recorded elsewhere in the patient record. RESULTS: The mean number of errors per form was 2.17 (95% confidence interval (CI): 1.95-2.39), giving an overall error rate of 9% (95% CI: 8%-10.0%). Eighty-seven percent of forms examined contained inaccuracies, ranging from one to nine errors (4%-38%). Some parameters were more prone to errors, ranging from 1% to 28%. There was no evidence of total errors varying by trainee grade (analysis of variance (ANOVA) p-value: 0.34). CONCLUSIONS: Error rates were in line with the literature. Results did not support restricting data entry to senior trainees.

The utility of MRI scans for a painful knee in the elderly patient.

INTRODUCTION: We assess the requesting patterns and overall utility of MRI scans in our institution over a 6-month period for knee pain in an elderly population. METHODS: We performed a retrospective cohort study analysing patients undergoing a knee MRI between June 2018 and January 2019. Clinical notes were reviewed to determine the nature of any surgical intervention that was performed as a result of the MRI findings. A simple economic analysis was then performed using local pricing information. RESULTS: One hundred and nine MRI scans were performed. The majority of scans were ordered by primary care physicians with no preceding plain radiographs (55%, n = 60). Meniscal tears were reported in 68% of patients. Degenerative changes were noted in 82% of patients. One patient was noted to have a flipped meniscal fragment. This was the only patient to undergo surgical intervention of any kind. Univariate analysis demonstrated no correlation between the presence of a meniscal tear (p = 0.61) or degeneration (p = 0.56) and the need for intervention. The only significant predictor of intervention was the presence of locking (p < 0.001). For the 101 patients that underwent unnecessary MRI scans, our institution would have saved €17,170 in unnecessary costs over 6 months. CONCLUSION: We suggest that all elderly patients with knee pain undergo plain radiographs before MRI scan and only those with locking should be considered for an MRI scan at all. Primary care physicians are overusing MRI as an imaging modality in this cohort at a cost of over €30,000 per year to our institution.

Day of Surgery Admission in Total Joint Arthroplasty: Why Are Surgeries Cancelled? An Analysis of 3195 Planned Procedures and 114 Cancellations.

Background. Day of surgery admission (DOSA) is becoming standard practice as a means of reducing cost in total joint arthroplasty. Aims. The aim of our study was to audit the use of DOSA in a specialty hospital and identify reasons for cancellation. Methods. A retrospective study of patients presenting for hip or knee arthroplasty between 2008 and 2013 was performed. All patients were assessed at the preoperative assessment clinic (PAC). Results. Of 3195 patients deemed fit for surgery, 114 patients (3.5%) had their surgery cancelled. Ninety-two cancellations (80%) were due to the patient being deemed medically unsuitable for surgery by the anaesthetist. Cardiac disease was the most common reason for cancellation (n = 27), followed by pulmonary disease (n = 22). 77 patients (67.5%) had their operation rescheduled and successfully performed in our institution at a later date. Conclusion. DOSA is associated with a low rate of cancellations on the day of surgery. Patients with cardiorespiratory comorbidities are at greatest risk of cancellation.

Surgical hip dislocation does not result in atrophy or fatty infiltration of periarticular hip muscles.

Surgical hip dislocation is the gold standard for treatment of femoroacetabular impingement (FAI). It utilizes an intermuscular and internervous approach to the hip. Concerns have been expressed that this approach causes soft tissue trauma resulting in post-operative muscle weakness of patients undergoing this procedure. We therefore asked whether surgical hip dislocation leads to (i) atrophy (decreased muscle diameter or cross-sectional area [CSA]) and (ii) degeneration (fatty infiltration) of 18 evaluated periarticular hip muscles. We retrospectively evaluated 32 patients (34 hips) following surgical hip dislocation for the treatment of FAI using pre and post-operative magnetic resonance (MR) arthrography of the hip. We evaluated muscle diameter, CSA and degree of fatty infiltration according to Goutallier for 18 periarticular hip muscles on axial and sagittal views. The mean interval between pre and post-operative MR was 1.9 ± 1.5 years (range, 0.4-6.1 years). Pre and post-operative muscle diameter and CSA of all 18 evaluated hip muscles did not differ. There was no post-operative change in the Goutallier classification for any of the evaluated 18 muscles. No muscle had post-operative degeneration higher than Grade 1 according to Goutallier. No atrophy or degeneration of periarticular hip muscles could be found following surgical hip dislocation for treatment of FAI. Any raised concerns about the invasiveness and potential muscle trauma for this type of surgery are unfounded. Level III, retrospective comparative study. See guidelines for authors for a complete description of levels of evidence.

Anti-biofilm activity of sub-inhibitory povidone-iodine concentrations against Staphylococcus epidermidis and Staphylococcus aureus.

Biomaterial-related infections continue to hamper the success of reconstructive and arthroplasty procedures in orthopaedic surgery. Staphylococci are the most common etiologic agents, with biofilm formation representing a major virulence factor. Biofilms increase bacterial resistance to antimicrobial agents and host immune responses. In staphylococci, production of polysaccharide intercellular adhesin (PIA) by the enzyme products of the icaADBC operon is the best understood mechanism of biofilm development, making the ica genes a potential target for biofilm inhibitors. In this study we report that the antibacterial agent povidone-iodine (PI) also has anti-biofilm activity against Staphylococcus epidermidis and Staphylococcus aureus at sub-inhibitory concentrations (p < 0.001). Inhibition of biofilm by PI correlated with decreased transcription of the icaADBC operon, which in turn correlated with activation of the icaR transcriptional repressor in Staphylococcus epidermidis. These data reveal an additional therapeutic benefit of PI and suggest that studies to evaluate suitability of PI as biomaterial coating agent to reduce device-related infections are merited.

Hydrogen peroxide induced repression of icaADBC transcription and biofilm development in Staphylococcus epidermidis.

Expression of the icaADBC-encoded polysaccharide intercellular adhesion by Staphylococcus epidermidis promotes biofilm formation and represents an important virulence factor in biomaterial-related infections following orthopedic surgery. Biofilm development by the pathogen can be viewed as a protective reaction to environmental stressors including osmotic stress, thermal stress, and antimicrobial chemotherapy. Oxidative stress, arising from the release of toxic oxygen radicals by polymorphonuclear cells, is encountered by bacteria entering the body perioperatively. Evasion of this and other cell-mediated immune responses by pathogenic bacteria plays an important role in the development of chronic biomaterial-related infection. Here we investigated the impact of sublethal oxidative stress induced by H2O2 (<18 mM) on S. epidermidis biofilm formation. S. epidermidis grown in brain heart infusion (BHI) media supplemented with 5 mM H2O2 or 10 mM H2O2 formed significantly less biofilm (p < 0.01 and p < 0.001, respectively) than bacteria grown in BHI alone. Consistent with this, using reverse transcription-polymerase chain reaction expression of the ica locus was also shown to be reduced by subinhibitory concentrations of H2O2. Furthermore, diminished ica operon expression correlated with increased expression of icaR, which encodes a repressor of icaADBC. Thus, these data suggest that mild oxidative stress downregulates biofilm development by S. epidermidis and may have potential in a therapeutic context.