Plain films are not accurate in planning internal fixation in vancouver type B1 periprosthetic femoral fractures and in distinguishing between subtypes B1 And B2.

BACKGROUND: While few studies analysed the diagnostic validity of preoperative radiographs in distinguishing between Vancouver type B1 and B2 periprosthetic femoral fractures (PFFs), no investigation has been conducted to assess the degree of diagnostic validity of preoperative radiographs in identifying the fracture course and planning the most appropriate treatment. We analysed the diagnostic validity of radiographs in detecting the fracture course and stem stability in Vancouver type B PFFs. METHODS: Vancouver type B PFFs with different fracture courses were randomly performed in 36 dried cadaveric femurs in which a femoral broach had previously been implanted. Radiographic images, taken in the coronal and sagittal views, were analysed by 5 orthopaedic surgeons and 2 radiologists who were asked to reproduce the fracture course and to evaluate stem stability. A scoring system was used to determine the injured femoral cortex correctly identified by the examiners. RESULTS: The identification of the fracture course was scored as poor in 52.4% and 56.%, fair in 23% and 23.4% and good in 24.6% and 19.8%, The identification of the fracture course in the coronal and axial vies radiographs was scored in coronal and axial view radiographs respectively. There was no significant difference in the average score obtained by senior and young examiners. In the coronal plane, the fracture course was poorly identified by all examiners in 11 (30.5%) femurs and by 5 or more examiners in 17 (47%). The fracture course was correctly identified by 5 or more examiners in 8 femurs (22%). A vertical fracture involving an emidiaphysis was found in 8 of the 11 femurs in which the PFF was poorly diagnosed by all examiners. Stem instability was correctly diagnosed in 45% of cases. CONCLUSIONS: In type B PFFs preoperative radiographs show a reduced diagnostic validity in identifying the fracture course and, hence, in planning a correct treatment. Potentially unstable vertical fractures involving an emidiaphysis are likely to be poorly diagnosed since most of the fracture course is hidden by the femoral stem. In cementless stems the diagnostic validity of radiographs in diagnosing between Vancouver type B1 and B2 seems to be lower than that reported for cemented stems.

Is postoperative hyponatremia a real threat for total hip and knee arthroplasty surgery?

Postoperative hyponatremia (POH) is thought to be a fearsome complication of orthopedic surgery. Primary aim of this cohort study was to evaluate the incidence of POH and its clinical relevance in elective surgery, outlining differences between total knee arthroplasty (TKA) and total hip arthroplasty, looking for the presence of any risk factor commonly related to POH.Four hundred two patients that underwent total hip arthroplasty and total knee arthroplasty performed between 2016 and 2017 were retrospectively examined. Serum electrolytes, hemoglobin, hematocrit, glucose, and creatinine were evaluated preoperatively and at day 0-I-II from surgery. Age, sex, body mass index, comorbidities, drugs, surgery data, transfusions, postoperative symptoms, and length of stay (LOS) were determined. All surgeries were performed by the same equipe. Patients had the same perioperative management, excluded those that took thiazides, already at risk of POH.Patients were divided in 2 groups: group A, patients with normal postoperative natremia (294 patients) and group B, patients who developed POH (108, 26.9%); 66.7% of these developed POH within 24 hours postoperatively. In group B mean postoperative natremia was 133.38 (127.78-134.85) mmol/L. Two patients (1.8%) developed moderate hyponatremia, no severe hyponatremia was documented. Type of surgery, operation time, LOS, and presence of postoperative symptoms did not show statistically significant differences within groups. At multivariate logistic analysis chronic use of thiazides was the only variable associated to a decreased risk of developing POH (OR = 0.39; P = .03). Hemoglobin postoperative values (OR = 1.22; P = .03), the need of postoperative transfusion (OR = 2.50; P = .02) and diabetes (OR = 2.70; P = .01) were associated to an increased risk of POH.Although 26.9% of our patients exhibited POH, the onset of this disorder had no implication on postoperative symptoms and on LOS. Diabetes and transfusion are factors most often associated to POH.