Quality monitoring is increasingly important to support and assure sustainability of the Orthopaedic practice. Many surgeons in a non-academic setting lack the resources to accurately monitor quality of care. Widespread use of electronic medical records (EMR) provides easier access to medical information and facilitates its analysis. However, manual review of EMRs is inefficient and costly. Artificial Intelligence (AI) software has allowed for development of automated search algorithms for extracting relevant complications from EMRs. We questioned whether an AI supported algorithm could be used to provide accurate feedback on the quality of care following Total Hip Arthroplasty (THA) in a high-volume, non-academic setting. 532 Consecutive patients underwent 613 THA between January 1st and December 31st, 2017. Patients were prospectively followed pre-op, 6 weeks, 3 months and 1 year. They were seen by the surgeon who created clinical notes and reported every adverse event. A random derivation cohort (100 patients, 115 hips) was used to determine accuracy. The algorithm was compared to manual extraction to validate performance in raw data extraction. The full cohort (532 patients, 613 hips) was used to determine its recall, precision and F-value.INTRODUCTION
METHODS
Patient related outcome measures (PROMS) are now routinely undertaken in patients undergoing hip arthroplasty. These are in the form of the Oxford Hip Score (OHS) and EQ5D questionnaires pre-operation and at 6 months' post operation. MYMOPS is a patient specific outcome measure that allows patients to list their individualised symptoms and activities that are limited and is used is other medical specialities but not currently within orthopaedic surgery. The aim of this study was to validate the MYMOPS questionnaire for use in hip arthroplasty by comparing it to the OHS. At a single centre, 50 patients were recruited to our prospective trial after ethical approval. A MYMOPS questionnaire and an OHS was filled in pre-operation and then at 6 months post-operatively. 6 patients filled in either form incorrectly and were excluded. The remaining 44 included 30 females and 14 males with an average age of 68.5 (range 35–90).Introduction
Patients/Materials & Methods
Radiological inclination (RI) is determined in part by operative inclination (OI), which is defined as the angle between the cup axis or handle and the sagittal plane. In lateral decubitus the theatre floor becomes a surrogate for the pelvic sagittal plane. Critically at the time of cup insertion if the pelvic sagittal plane is not parallel to the floor either because the upper hemi pelvis is internally rotated or adducted, RI can be much greater than expected. We have developed a simple Pelvic Orientation Device (POD) to help achieve a horizontal pelvic sagittal plane. The POD is a 3-sided square with flat footplates that are placed against the patient's posterior superior iliac spines following initial positioning (figure 1). A digital inclinometer is then placed parallel and perpendicular to the patient to give readings of internal rotation and adduction, which can then be corrected. A model representing the posterior aspect of the pelvis was created. This permitted known movement in two planes to simulate internal rotation and adduction of the upper hemi pelvis, with 15 known pre-set positions. 20 participants tested the POD in 5 random, blinded position combinations, providing 200 readings. The accuracy was measured by subtracting each reading from the known value.Introduction
Methods
Recent studies have demonstrated that implant-specific blood metal ion thresholds exist in unilateral and bilateral metal-on-metal (MoM) hip arthroplasty patients, with these thresholds being most effective for identifying patients at low-risk of adverse reactions to metal debris (ARMD). We investigated whether these new blood metal ion thresholds could effectively identify patients at risk of ARMD in an external cohort of MoM hip arthroplasty patients. We performed a validation study involving 803 MoM hip arthroplasties implanted in 710 patients at three European centres (323=unilateral Birmingham Hip Resurfacing (BHR); 93=bilateral BHR; 294=unilateral Corail-Pinnacle). All patients underwent whole blood metal ion sampling. Patients were divided into those with ARMD (revised for ARMD or ARMD on imaging; n=75), and those without ARMD (n=635). Previously devised implant-specific blood metal ion thresholds (cobalt=2.15μg/l for unilateral BHR; maximum cobalt or chromium=5.5μg/l for bilateral BHR; cobalt=3.57μg/l for unilateral Corail-Pinnacle) were applied to the validation cohort, with receiver operating characteristic curve analysis used to establish the discriminatory characteristics for each respective threshold. The area under the curve, sensitivity, specificity, positive predictive value and negative predictive value for distinguishing between patients with and without ARMD for each implant-specific threshold were respectively: unilateral BHR=89.4% (95% CI=82.8%-96.0%), 78.9%, 86.7%, 44.1%, 96.9%; bilateral BHR=89.2% (95% CI=81.3%-97.1%), 70.6%, 86.8%, 54.5%, 93.0%; unilateral Corail-Pinnacle=76.9% (95% CI=63.9%-90.0%), 65.0%, 85.4%, 24.5%, 97.1%. The 7μg/l UK MHRA threshold missed significantly more patients with ARMD compared with the implant-specific thresholds (4.9% vs. 2.8%; p=0.0003). This external multi-centre validation study has confirmed that MoM hip arthroplasty patients with blood metal ion levels below newly devised implant-specific thresholds have a low-risk of ARMD. Compared to implant-specific thresholds, the currently proposed fixed MHRA threshold missed more patients with ARMD. We recommend using implant-specific thresholds over fixed thresholds when managing MoM hip arthroplasty patients.
