Aims This study evaluates risk factors influencing fracture characteristics for postoperative periprosthetic femoral fractures (PFFs) around cemented stems in total hip arthroplasty. Methods Data were collected for PFF patients admitted to eight UK centres between 25 May 2006 and 1 March 2020. Radiographs were assessed for Unified Classification System (UCS) grade and AO/OTA type. Statistical comparisons investigated relationships by age, gender, and stem fixation philosophy (polished taper-slip (PTS) vs composite beam (CB)). The effect of multiple variables was estimated using multinomial logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs). Surgical treatment (revision vs fixation) was compared by UCS grade and AO/OTA type. Results A total of 584 cases were included. Median age was 79.1 years (interquartile range 72.0 to 86.0), 312 (53.6%) patients were female, and 495 (85.1%) stems were PTS. The commonest UCS grade was type B1 (278, 47.6%). The most common AO/OTA type was spiral (352, 60.3%). Metaphyseal split fractures occurred only with PTS stems with an incidence of 10.1%. Male sex was associated with a five-fold reduction in odds of a type C fracture (OR 0.22 (95% CI 0.12 to 0.41); p < 0.001) compared to a type B fracture. CB stems were associated with significantly increased odds of transverse fracture (OR 9.51 (95% CI 3.72 to 24.34); p < 0.001) and wedge fracture (OR 3.72 (95% CI 1.16 to 11.95); p = 0.027) compared to PTS stems. Both UCS grade and AO/OTA type differed significantly (p < 0.001 and p = 0.001, respectively) between the revision and fixation groups but a similar proportion of B1 fractures underwent revision compared to fixation (45.3% vs 50.6%). Conclusion The commonest fracture types are B1 and spiral fractures. PTS stems are exclusively associated with metaphyseal split fractures, but their incidence is low. Males have lower odds of UCS grade C fractures compared to females. CB stems have higher odds of bending type fractures (transverse and wedge) compared to PTS stems. There is considerable variation in practice when treating B1 fractures around cemented stems. Cite this article: Bone Jt Open 2021;2(7):466–475.

Aims This aim of this study was to assess the reliability and validity of the Unified Classification System (UCS) for postoperative periprosthetic femoral fractures (PFFs) around cemented polished taper-slip (PTS) stems. Methods Radiographs of 71 patients with a PFF admitted consecutively at two centres between 25 February 2012 and 19 May 2020 were collated by an independent investigator. Six observers (three hip consultants and three trainees) were familiarized with the UCS. Each PFF was classified on two separate occasions, with a mean time between assessments of 22.7 days (16 to 29). Interobserver reliability for more than two observers was assessed using percentage agreement and Fleiss’ kappa statistic. Intraobserver reliability between two observers was calculated with Cohen kappa statistic. Validity was tested on surgically managed UCS type B PFFs where stem stability was documented in operation notes (n = 50). Validity was assessed using percentage agreement and Cohen kappa statistic between radiological assessment and intraoperative findings. Kappa statistics were interpreted using Landis and Koch criteria. All six observers were blinded to operation notes and postoperative radiographs. Results Interobserver reliability percentage agreement was 58.5% and the overall kappa value was 0.442 (moderate agreement). Lowest kappa values were seen for type B fractures (0.095 to 0.360). The mean intraobserver reliability kappa value was 0.672 (0.447 to 0.867), indicating substantial agreement. Validity percentage agreement was 65.7% and the mean kappa value was 0.300 (0.160 to 0.4400) indicating only fair agreement. Conclusion This study demonstrates that the UCS is unsatisfactory for the classification of PFFs around PTS stems, and that it has considerably lower reliability and validity than previously described for other stem types. Radiological PTS stem loosening in the presence of PFF is poorly defined and formal intraoperative testing of stem stability is recommended. Cite this article: Bone Joint J 2021;103-B(8):1339–1344.

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Combinations of spectroscopic analysis and microscopic techniques are used across many disciplines of scientific research, including material science, chemistry and biology. X-ray spectromicroscopy, in particular, is a powerful tool used for studying chemical state distributions at the micro and nano scales. With the beam fixed, a specimen is typically rastered through the probe with continuous motion and a range of multimodal data is collected at fixed time intervals. The application of this technique is limited in some areas due to: long scanning times to collect the data, either because of the area/volume under study or the compositional properties of the specimen; and material degradation due to the dose absorbed during the measurement. In this work, we propose a novel approach for reducing the dose and scanning times by undersampling the raster data. This is achieved by skipping rows within scans and reconstructing the x-ray spectromicroscopic measurements using low-rank matrix completion. The new method is robust and allows for 5 to 6-fold reduction in sampling. Experimental results obtained on real data are illustrated.

Introduction: Intertrochanteric fractures are predominantly treated by dynamic hip screw (DHS) fixation. However, recent evidence has found acceptable clinical results following hemiarthroplasty for these fractures. Thus, a systematic review was conducted to compare hemiarthroplasty with DHS fixation for intertrochanteric fractures. Methods: A computerised search was performed, using the databases Medline, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials, with supplementation from Google Scholar and appropriate reference lists. Studies with comparative data comparing clinical outcomes of hemiarthroplasty versus DHS fixation were included. Data were extracted and quality assessment of the papers performed by 2 reviewers. Results: 320 articles were independently reviewed by the investigators. A total of 10 studies met the inclusion criteria, comprising 2 randomised controlled trials and 8 cohort designs. 7 of the studies assessed unstable fracture patterns. There was no difference in operating time (SMD −1.169 min; 95% CI, −0.657 to 0.689) or blood transfusion volume (SMD−0.110 units; 95% CI, −0.520 to 0.891) between modalities. There was also no difference in length of stay (SMD −0.778 days; 95% CI, −0.606 to 0.336), mortality (RR 0.942; 95% CI, 0.749–1.183) or major complications. Hemiarthroplasty conferred significantly better Harris Hip Scores at 12 months (SMD 12.3; 95% CI, 0.0135–2.789) and allowed earlier weight-bearing than DHS fixation. Discussion: Qualitative and quantitative compilation of the included studies demonstrates hemiarthroplasty to result in better functional scores and a quicker time to weight-bearing than DHS fixation for intertrochanteric fractures. Results are comparable for other major parameters, including operative time, length of stay and mortality. Thus, hemiarthroplasty is a suitable alternative to DHS fixation for unstable intertrochanteric fractures in elderly patients.