Aims. Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture. Methods. We retrospectively included 340 patients who underwent conversion THA after internal fixation for femoral neck fracture from January 2008 to September 2020. Those patients constituted two groups: noninfected patients and patients diagnosed with FRI according to the 2013 International Consensus Meeting Criteria. Receiver operating characteristic (ROC) curves were used to determine maximum sensitivity and specificity of these two preoperative ratios. The diagnostic performance of the two ratios combined with preoperative CRP or ESR was also evaluated. Results. The numbers of patients with and without FRI were 19 (5.6%) and 321 (94.4%), respectively. Areas under the ROC curve for diagnosing FRI were 0.763 for MLR, 0.686 for NLR, 0.905 for CRP, and 0.769 for ESR. Based on the Youden index, the optimal predictive cutoffs were 0.25 for MLR and 2.38 for NLR. Sensitivity and specificity were 78.9% and 71.0% for MLR, and 78.9% and 56.4% for NLR, respectively. The combination of CRP with MLR showed a sensitivity of 84.2% and specificity of 94.6%, while the corresponding values for the combination of CRP with NLR were 89.5% and 91.5%, respectively. Conclusion. The presence of preoperative FRI among patients undergoing conversion THA after internal fixation for femoral neck fracture should be determined. The combination of preoperative CRP with NLR is sensitive tool for screening FRI in those patients. Cite this article: Bone Joint J 2021;103-B(9):1534–1540

Aims

The purpose of this study was to develop a convolutional neural network (CNN) for fracture detection, classification, and identification of greater tuberosity displacement ≥ 1 cm, neck-shaft angle (NSA) ≤ 100°, shaft translation, and articular fracture involvement, on plain radiographs.

A prospective study was performed to develop a clinical prediction rule that incorporated demographic and clinical factors predictive of a fracture of the scaphoid. Of 260 consecutive patients with a clinically suspected or radiologically confirmed scaphoid fracture, 223 returned for evaluation two weeks after injury and formed the basis of our analysis. Patients were evaluated within 72 hours of injury and at approximately two and six weeks after injury using clinical assessment and standard radiographs. Demographic data and the results of seven specific tests in the clinical examination were recorded.

There were 116 (52%) men and their mean age was 33 years (13 to 95; sd 17.9). In 62 patients (28%) a scaphoid fracture was confirmed. A logistic regression model identified male gender (p = 0.002), sports injury (p = 0.004), anatomical snuff box pain on ulnar deviation of the wrist within 72 hours of injury (p < 0.001), and scaphoid tubercle tenderness at two weeks (p < 0.001) as independent predictors of fracture. All patients with no pain at the anatomical snuff box on ulnar deviation of the wrist within 72 hours of injury did not have a fracture (n = 72, 32%). With four independently significant factors positive, the risk of fracture was 91%.

Our study has demonstrated that clinical prediction rules have a considerable influence on the probability of a suspected scaphoid fracture. This will help improve the use of supplementary investigations where the diagnosis remains in doubt.