The World Health Organisation (WHO) Surgical Safety checklist is an evidence-based tool shown to reduce surgery-related morbidity and mortality. Despite audits showing 96% checklist compliance, our hospital had 3 surgical never events in 10 months, 2 of which were in orthopaedics. By March 2018, the authors aimed to achieve 100% compliance with all 5 sections of the WHO Five Steps to Safer Surgery bundle for all surgical patients. Additionally, the authors aimed to assess the impact of the quality of bundle delivery on preventable errors related to human factors. Quantitative assessment involved direct observations of compliance in theatres. Qualitative data in the form of rich, descriptive observations of events and discussions held during checklist delivery was analysed thematically. Interventions included trust-wide policy changes, awareness sessions, introduction of briefing and debrief proformas and documented prosthesis checks. For elective surgeries, checklist compliance increased to 100% in 4 of 5 sections of the bundle. The incidence of reported preventable critical incidents decreased from 6.7% to 2.4%. A chi-squared test of independence demonstrated a significant relationship between the implementation of changes and completion of the checklist, X2 (1, N = 1019) = 25.69, p < 0.0001. Thematic analysis identified leadership, accountability, engagement, empowerment, communication, and teamwork as factors promoting effective checklist use. Our findings highlight the benefits of a qualitative approach to auditing checklists. Exploring the role of human factors and promoting staff awareness and engagement improves checklist compliance and enhances its effectiveness in reducing surgery-related adverse outcomes.

Hip simulator studies have shown reduced hip offset can cause microseparation and increased wear in hard-on-hard hip bearings. However this has not been analysed yet in vivo. We studied the effect of reduced hip offset on serum metal ion levels in patients with metal-on-metal (MoM) hip arthroplasty.

From all patients who underwent unilateral MoM bearing hip arthroplasty between 2005 and 2009, 63 patients had complete clinical evaluation, measurement of serum chromium and cobalt ion levels as well as biomechanical measurements on pre- and post operative radiographs (cup inclination, head inclination, change in hip offset and change in hip length.)

Ten arthroplasties were revised due to adverse metal reaction and six patients awaiting revision. 55% of ASR hips showed higher metal ions (>7 ppb) whereas only 15% of non-ASR hips had higher ion levels. Patients with reduced postoperative hip offset by more than 5 mm had significantly higher mean metal ion levels compared to the the rest of the hips (31.8 ppb vs. 7.4 ppb, p=0.002). On subgroup analysis this effect was present in non-ASR hips (18.7 ppb vs. 4.7 ppb, p=0.025) but was not significant in ASR hips (29.6 ppb vs. 16.3 ppb, p=0.347).

Our study demonstrated significantly higher serum metal ion levels in patients who lost more than 5 mm hip offset after arthroplasty. Reduced soft tissue tension leading to microseparation of the articulation and edge loading is a theoretical explanation for this effect. This may be relevant in other hard bearings such as ceramic-on-ceramic as well.