Several radiological methods of measuring anteversion of the acetabular component after total hip replacement (THR) have been described. These studies used different definitions and reference planes to compare methods, allowing for misinterpretation of the results. We compared the reliability and accuracy of five current methods using plain radiographs (those of Lewinnek, Widmer, Liaw, Pradhan, and Woo and Morrey) with CT measurements, using the same definition and reference plane. We retrospectively studied the plain radiographs and CT scans in 84 hips of 84 patients who underwent primary THR. Intra- and inter-observer reliability were high for the measurement of inclination and anteversion with all methods on plain radiographs and CT scans. The measurements of inclination on plain radiographs were similar to the measurements using CT (p = 0.043). The mean difference between CT measurements was 0.6° (-5.9° to 6.8°). Measurements using Widmer’s method were the most similar to those using CT (p = 0.088), with a mean difference between CT measurements of -0.9° (-10.4° to 9.1°), whereas the other four methods differed significantly from those using CT (p < 0.001). This study has shown that Widmer’s method is the best for evaluating the anteversion of the acetabular component on plain radiographs. Cite this article: Bone Joint J 2014; 96-B:597–603

The radiological evaluation of the anterolateral femoral head is an essential tool for the assessment of the cam type of femoroacetabular impingement. CT, MRI and frog lateral plain radiographs have all been suggested as imaging options for this type of lesion. The alpha angle is accepted as a reliable indicator of the cam type of impingement and may also be used as an assessment for the successful operative correction of the cam lesion. We studied the alpha angles of 32 consecutive patients with femoroacetabular impingement. The angle measured on frog lateral radiographs using templating tools was compared with that measured on CT scans in order to assess the reliability of the frog lateral view in analysing the alpha angle in cam impingement. A high interobserver reliability was noted for the assessment of the alpha angle on the frog lateral view with an intraclass correlation coefficient of 0.83. The mean alpha angle measured on the frog lateral view was 58.71° (32° to 83.3°) and that by CT was 65.11° (30° to 102°). A poor intraclass correlation coefficient (0.08) was noted between the measurements using the two systems. The frog lateral plain radiograph is not reliable for measuring the alpha angle. Various factors may be responsible for this such as the projection of the radiograph, the positioning of the patient and the quality of the image. CT may be necessary for accurate measurement of the alpha angle

Plain radiographs of 67 acute spinal compression fractures in 49 patients were analysed by subjective and objective criteria, using CT scans as the diagnostic standard for the diagnosis of burst fracture. Discriminant analysis correctly predicted the type of fracture in 88% of cases. Burst fractures, however, were almost as frequently misdiagnosed as being wedge compression fractures using this technique, compared with the reading of 25 films from patients without previous information. A quarter of the injuries would have been misdiagnosed had reliance been placed solely on the plain radiographs. CT scans of all patients with acute spinal compression fractures should be considered to decrease this potentially serious diagnostic error

Introduction: The most widely accepted method for measuring bone mineral density (BMD) is Dual-energy X-ray Absorptionmetry (DXA). However, the need for relatively expensive equipment and trained personnel lower the accessibility of DXA as a routine screening tool. Plain pelvic X-ray radiography is a simple and inexpensive examination. In principal, the gray level of the bone in the X-ray radiograph is related to BMD. However, several factors render plain X-ray radiographs of the hip unsuitable for BMD measurements, mainly the variability in X-ray exposure levels and the soft tissue surrounding the bone. In this study, we aimed to develop new modifications of plain X-ray radiography of the proximal femur. Patients and methods: The study population consisted of 18 women with an average age of 77 years (range 57–96 years) who were hospitalized due to a low-energy fracture of the neck of the femur. Each patient’s contralateral hip was radiographed with an aluminium step-wedge positioned near the hip as a standard reference, using a computerized radiography system. A DXA examination of the same hip followed the plain radiograph. On each radiograph, regions of interest (ROI) were determined in concordance with the ROI of the DXA examination. The mean gray level was measured for each ROI. The neck-shaft angle and the femoral head diameter were also measured. Results: Comparing the gray levels of the plain radiograph with the BMD levels obtained by the DXA revealed a coefficient ratio of R=0.499. Correction of the gray levels using the step wedge as a standard reference revealed a ratio of R=0.576. If further correction was made with measurement of the soft tissue gray levels, a ratio of R=0.708 was obtained. Using the anatomical measurements (neck-shaft angle and femoral head diameter), a ratio of R=0.948 was obtained. Conclusion: This study shows that a plain digital radiograph of the pelvis can provide valuable information concerning the bone mineral content of the proximal femur, which is comparable to the results of the DXA examination. Ultimately, the research can lead to the development of a fast, available and relatively inexpensive technique to diagnose osteoporosis

Metal-on-metal total hip replacement has been targeted at younger patients with anticipated long-term survival, but the effect of the production of metal ions is a concern because of their possible toxicity to cells. We have reviewed the results of the use of the Ultima hybrid metal-on-metal total hip replacement, with a cemented polished tapered femoral component with a 28 mm diameter and a cobalt-chrome (CoCr) modular head, articulating with a 28 mm CoCr acetabular bearing surface secured in a titanium alloy uncemented shell. Between 1997 and 2004, 545 patients with 652 affected hips underwent replacement using this system. Up to 31 January 2008, 90 (13.8%) hips in 82 patients had been revised. Pain was the sole reason for revision in 44 hips (48.9%) of which 35 had normal plain radiographs. Peri-prosthetic fractures occurred in 17 hips (18.9%) with early dislocation in three (3.3%) and late dislocation in 16 (17.8%). Infection was found in nine hips (10.0%). At operation, a range of changes was noted including cavities containing cloudy fluid under pressure, necrotic soft tissues with avulsed tendons and denuded osteonecrotic upper femora. Corrosion was frequently observed on the retrieved cemented part of the femoral component. Typically, the peri-operative findings confirmed those found on pre-operative metal artefact reduction sequence MRI and histological examination showed severe necrosis. Metal artefact reduction sequence MRI proved to be useful when investigating these patients with pain in the absence of adverse plain radiological features

Radiographic evaluation of the anterolateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. Alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion. The aim of our study was to analyse the reliability of frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement. Thirty two patients who presented with femoroac-etabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans. A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems. Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate prediction of alpha angle

The purpose of our study was to assess the reproducibility and reliability of traditional radiographic methods of diagnosing trochlear dysplasia compared with the gold standard of MRI. Plain radiographs and MRI scans of 36 knees in 28 patients with proven trochlear dysplasia were compared with 18 controls in a single surgeon's practice. The sulcus angle on MRI and axial radiographs was measured. The lateral radiograph was assessed for adequacy, the crossing sign and the trochlear bump sign. The mean axial (radiograph) and MRI sulcus angles in the dysplastic group were 145° and 158° respectively (p=0.0001) compared to 135° and 138° in the control group (p=0.09). The crossing sign was present in 34 out of 36 lateral radiographs in the dysplastic group and 8 out of 18 in the control group equating to a sensitivity of 94% and specificity of 56%. The quality of the lateral radiograph did not significantly alter the sensitivity or specificity of the crossing sign (p=0.01). The bump sign was present in 22 out of 36 lateral radiographs in the dysplastic group and 1 out of 18 in the control group equating to a sensitivity of 61% and specificity of 94%. Our study shows that an increased radiographic sulcus angle is reliable in diagnosing trochlear dysplasia but underestimates it. The bump sign is a reliable predictor of trochlear dysplasia. The crossing sign is sensitive but not specific in diagnosing dysplasia

Background. Lisfranc fracture dislocations are uncommon injuries, which frequently require surgical intervention. Currently, there is varying evidence on the diagnostic utility of plain radiographs (XR) and CT in identifying Lisfranc injuries and concomitant fractures. Our aim was to identify the utility of XR as compared to CT, with the nul hypothesis that there was no difference in fracture identification. Methods. A retrospective assessment of patients who had sustained a Lisfranc injury between 2013 and 2022 across two trauma centres within the United Kingdom who underwent surgery. Pre-operative XR and CT images were reviewed independently by 2 reviewers to identify the presence of associated fractures. Results. A total of 175 patients were included. Our assessment identified that XR images significantly under-diagnosed all metatarsal and midfoot fractures. The largest discrepancies between XR and CT in their rates of detection were in fractures of the cuboid (5.7% vs 28%, p<0.001), medial cuneiform (20% vs 51%, p=0.008), lateral cuneiform (4% vs 36%, p=0.113), second metatarsal (57% vs 82%, p<0.001), third metatarsal (37% vs 61%, p<0.001) and fourth metatarsal (26% vs 43%, p<0.001). As compared to CT, the sensitivity of XR was low. The lowest sensitivity for identification however was lateral foot injuries, specifically fractures of the lateral cuneiform (sensitivity 7.94%, specificity 97.3%), cuboid (sensitivity 18.37%, specificity 99.21%), fourth (sensitivity 46.7%, specificity 89.80%) and fifth metatarsal (sensitivity 45.00%, specificity 96.10%). Conclusion. From our analysis, we can determine that XR significantly under-diagnoses associated injuries in patient sustaining an unstable Lisfranc injury, with lateral foot injuries being the worst identified. We advised the use of CT imaging in all cases for appropriate surgical planning

Introduction Controversy exists regarding the value of lumbar plain x-ray imaging for patients with low back pain with or without radicular pain (. 1. ,. 2. ,. 3. ). Methods Plain film x-ray and CT imaging from thirty (30; 19M:11F) consecutive patients (aged 20–68 years; mean 42 years) presenting to a public hospital’s spinal pain clinic with low back pain +/− radicular pain, without a history suggesting ‘red flag’ pathology, was examined and measured to determine the incidence of retrolisthesis of L5 on S1 and any associated disc bulge/protrusion. Results Sixteen of the thirty patients (53%) had retrolisthesis of L5 on S1 ranging from 2–9 mm; these patients had either intervertebral disc bulging or protrusion on CT examination ranging from 3–7 mm into the spinal canal. Fourteen patients (47%) without retrolisthesis (control group) did not show any retrolisthesis and the CT did not show any bulge/protrusion. On categorizing x-ray and CT pathology as being present or not, the well positioned ie. true lateral plain x-ray film revealed a sensitivity and specificity of 100% ([95% Conf. Int. = [89%–100%]) for bulge/protrusion in this preliminary study. On taking into account the numerical values of x-ray and CT, a significant correlation (p< 0.001) was found. Discussion In this preliminary study, carefully positioned lateral lumbosacral x-ray films showing L5 on S1 retrolisthesis are highly suggestive of intervertebral disc bulge/protrusion, providing valuable guidance for consideration of lumbosacral CT of MRI examination that is likely to be contributory regarding such pathology

Introduction: Several factors render plain X-ray radiographs of the hip unsuitable for bone mineral density measurements, mainly variability in X-ray exposure levels and soft tissue surrounding the bone. We present modification of proximal femur digital radiographs to compensate for these interfering factors. Methods: The study population consisted of 99 women, in three groups: 1 – elderly, sustaining a fracture of the neck of the femur. 2 – elderly, without a fracture. 3 – young. Each patient’s hip was radiographed with a brass step-wedge for standard reference. Dual-Energy X-ray Absorptiometry (DEXA) of the same hip was performed. On each radiograph, Regions Of Interest (ROIs) of the proximal femur were determined in concordance with ROI of the DEXA, together with three soft tissue regions surrounding the bone. Mean gray level was measured for each ROI. Results: The difference in gray level of the ROI within the proximal femur was not statistically significant between the groups. Correction of bone gray level to exposure level by dividing the gray level of the ROI to that of the step wedge, resulted in statistically significant difference between group 1 and either group 2 or group 3. Similar results were obtained by correction of bone gray level to soft tissue gray level. Using this method, multiple R. 2. of 0.62 was found predicting the DEXA value from the gray level of each ROI. Conclusions: After correction to the exposure level and to the soft tissue surrounding the bone, a plain digital radiograph of the pelvis can provide valuable information concerning the bone mineral content of the proximal femur. These preliminary results warrant further research aimed at exploring the potential value of this fast, accessible and relatively inexpensive technique to diagnose osteoporosis and the prediction of future fractures

Introduction: With increasing availability of CT scans their use in the investigation of the subtalar joint increases, whilst we continue to use plain x-ray. Using a standardised reporting protocol, we graded x-rays and CT scans to compare the diagnosis made using each modality. Materials and Methods: An atlas and reporting system of the subtalar joint was designed using a modification of Kellgren and Lawrence’s system. 50 consecutive CT scans of the subtalar joint were identified and saved along with paired plain x-rays of the foot and ankle. All investigations were anonymised. Scans were excluded if there were no plain films or there was evidence of previous trauma. Orthopaedic surgeons were asked to report on the 50 CT scans and 50 plain radiographs using the reporting protocol, commenting on two components for each investigation; the anterior and middle facets and the posterior facet of the subtalar joint. Results: In 33% of cases the facets of the subtalar joint could not be appreciated from the plain x-rays. The difference between the modalities in reported grade of degeneration of the anterior and middle facets of the subtalar joint was statistically significant (p= 0.014) but not for the posterior facet (0.726). When looking at the Spearman correlation coefficient, the anterior and middle facets had no correlation (r = − 0.067) although the posterior facet did (r = 0.029). Discussion: When looking at the posterior facet of the subtalar joint plain x-rays and CT scans give comparable results. When looking at the anterior and middle facets the information gained from the plain x-rays bears no resemblance to that gained from the CT scans. Conclusion: The plain x-ray is an inaccurate, unreliable method of investigating degenerate pathology of the subtalar joint and should be superseded, and perhaps replaced, by the CT scan

Objective: The purpose of the present study was to assess whether clinicians are actually able to evaluate the mechanical status of lengthening callus from plain radiographs. Materials and Methods: 36 rats were employed in this study. Their left femurs were lengthened by 6 mm as a bone lengthening model. Rats were euthanized at 4 8 12 and 16 weeks after lengthening. Both femora were X-rayed and then bone density parameters (bone mineral content, bone mineral density and bone area) of lengthening callus were measured using pQCT. Three-point bending test was performed to determine the mechanical strength of the both bones. We defined the ratio of the strength of lengthening side to control side as estimated strength recovery rate (%). Then 20 orthopaedic surgeons evaluated only the X-ray photographs and tried to estimate the relative mechanical strength (%) of the affected side compared to the control side. Results: Between the recovery percentage of mechanical strength and bone mineral content, a positive simple correlation (R2=0.11, p< 0.05) was seen. No significant correlation was seen between the recovery percentage of mechanical strength estimated by orthopaedists and the mechanical strength measured by three-point bending test (qualified doctors: R2=0.0793 p=0.291 unqualified doctors: R2=0.0523 p=0.394). Discussion and conclusion: It became obvious that to estimate the strength of lengthening callus from plain radiographs alone is quite difficult as compared with the studies of the simple fracture model that have been reported until now

Plain radiography has traditionally been used to investigate and monitor patients with adolescent idiopathic scoliosis. The X-ray allows a calculation of the Cobb angle which measures the degree of lateral curvature in the coronal plane. ISIS2 is a surface topography system which has evolved from ISIS, but with much higher precision and speed. It measures the three dimensional shape of the back using structured light and digital photography. This system has the benefit of not requiring any radiation. Lateral asymmetry is the ISIS clinical parameter estimating the curve of the spine in the coronal plane. The aim of this study was to compare this parameter to the Cobb angle measured on plain X-ray. Twelve patients with idiopathic adolescent scoliosis underwent both a standing AP spine X-ray and an ISIS2 scan on multiple occasions. Both scan and X-ray were done within one month of each other. No patient underwent surgery during the study period. The Cobb angle and the degree of lateral asymmetry were calculated. Twelve patients mean age 12.5 years (range 10-16) were investigated using both ISIS2 and X-ray. They had a mean 2.3 (1-5) combined investigations allowing for 30 comparisons. The correlation between the two measurements was r =0.63 (p=0.0002). The Cobb angle measured on ISIS2 was less than that measured by radiograph in 27 out of 30 comparisons. The mean difference between the measurements was mean 6.4° with a standard deviation of 8.2° and 95% confidence interval of 3.3° to 9.4°. In adolescent idiopathic scoliosis, curve severity and rib hump severity are related but measure different aspects of spinal deformity. As expected, these relate closely but not precisely. ISIS2 offers the promise of monitoring scoliosis precisely, without adverse effects from radiation. The small numbers in this series focus on the group of patients with mild to moderate curves at risk of progression. In this group, ISIS2 was able to identify curve stability or progression, without exposing the subjects to radiation

Aims

To explore the clinical relevance of joint space width (JSW) narrowing on standardized-flexion (SF) radiographs in the assessment of cartilage degeneration in specific subregions seen on MRI sequences in knee osteoarthritis (OA) with neutral, valgus, and varus alignments, and potential planning of partial knee arthroplasty.

To evaluate and describe the plain radiographic changes observed with time in fusions using SiS-CaP. We describe, for the first time, 4 stages of bone substitute fusion mass (BSFM) radiographic appearance in relation to time post-op. Retrospective, radiological evaluation. Over 200 plain radiographs were evaluated. 70 consecutive fusions for degenerative spinal stenosis were included, in all cases performed by the same surgeon using the same operative technique. Follow-up was from 3 months to 2 years post-op. Radiographs were evaluated for the presence or absence of SiS-CaP granules, bone formation and for evidence of pseudarthrosis. Trends were seen within the BSFM with respect to time. At 6-12 weeks post-op a ‘homogenous granular stage’ indicates the presence of the unchanged SiS-CaP. At 12 weeks, small pockets appear within the BSFM in the ‘vacuolation stage’, indicating bioresorption of the graft. Vacuoles become increasingly radio-opaque indicating bone proliferation during the ‘homogenous lamellar stage’. At variable time between 6 months and 2 years, the BSFM becomes encapsulated in the ‘cortication stage’ visible as a sclerotic rim around the BSFM. We have seen a clear trend in the behaviour of the fusion mass in this case series. The radiological stages we have described above can be closely correlated with previously reported in-vitro and in-vivo studies looking at the micro-function of SiS-CaP. We hope that this description will help to judge the progress of graft incorporation and fusion. Further study of inter and intra-observer correlation will be required

Introduction

There are conflicting views when assessing the best imaging modality by which to assess long leg alignment pre and post operatively for patients’ receiving primary total hip replacements. It has been a long standing standard that long-leg radiographs are used for measuring and interpreting alignment of the lower limb, but recently it has been suggested that CT imaging may be a better option for this assessment.

In total hip replacement, orientation of the cup is critical to the stability of the prosthesis. A new method to determine the angle of planar anteversion is described. A simple mathematical formula uses the measurements taken from anteroposterior radiographs to calculate the planar anteversion without reference to tables or charts.

An experimental study in vitro has shown the efficacy of the formula in giving results which are within a clinically acceptable range.

Aims. The aims of this study were: firstly, to investigate the influence of the thickness of cartilage at the sigmoid notch on the inclination of the distal radioulnar joint (DRUJ), and secondly, to compare the sensitivity and specificity of MRI with plain radiographs for the assessment of the inclination of the articular surface of the DRUJ in the coronal plane. . Patients and Methods. Contemporaneous MRI images and radiographs of 100 wrists from 98 asymptomatic patients (mean age 43 years, (16 to 67); 52 male, 53%) with no history of a fracture involving the wrist or surgery to the wrist, were reviewed. The thickness of the cartilage at the sigmoid notch, inclination of the DRUJ and Tolat Type of each DRUJ were determined. . Results. The assessment using MRI scans and cortical bone correlated well with radiographs, with a kappa value of 0.83. The mean difference between the inclination using the cortex and cartilage on MRI scans was 12°, leading to a change of Tolat type of inclination in 66% of wrists. No reverse oblique (Type 3) inclinations were found when using the cartilage to assess inclination. . Conclusion . These data revealed that when measuring the inclination of the DRUJ using cartilage, reverse oblique inclinations might not exist. The data suggest that performing an ulna shortening osteotomy might be reasonable even in distal radioulnar joints where the plain radiographic appearance suggests an unfavourable reverse oblique inclination in the coronal plane. We recommend using MRI to validate radiographs in those that appear to be reverse oblique (Tolat Type 3), as the true inclination might be different, thereby removing one possible contraindication to ulnar shortening. Cite this article: Bone Joint J 2017;99-B:369–75

The purpose of this study was to devise a simple but reliable radiological method of identifying a lumbosacral transitional vertebra (LSTV) with a solid bony bridge on sagittal MRI, which could then be applied to a lateral radiograph.

The vertical mid-vertebral angle (VMVA) and the vertical anterior vertebral angle (VAVA) of the three most caudal segments of the lumbar spine were measured on MRI and/or on a lateral radiograph in 92 patients with a LSTV and 94 controls, and the differences per segment (Diff-VMVA and Diff-VAVA) were calculated. The Diff-VMVA of the two most caudal vertebrae was significantly higher in the control group (25° (sd 8) than in patients with a LSTV (type 2a+b: 16° (sd 9), type 3a+b: -9° (sd 10), type 4: -5° (sd 7); p < 0.001). A Diff-VMVA of ≤ +10° identified a LSTV with a solid bony bridge (type 3+4) with a sensitivity of 100% and a specificity of 89% on MRI and a sensitivity of 94% and a specificity of 74% on a lateral radiograph. A sensitivity of 100% could be achieved with a cut-off value of 28° for the Diff-VAVA, but with a lower specificity (76%) on MRI than with Diff-VMVA.

Using this simple method (Diff-VMVA ≤ +10°), solid bony bridging of the posterior elements of a LSTV, and therefore the first adjacent mobile segment, can be easily identified without the need for additional imaging.

Cite this article: Bone Joint J 2013;95-B:1533–7.

Abstract. Aims. The aim of this study was to evaluate the indications for patients presenting with knee pain undergoing magnetic resonance imaging of the knee prior to referral to the orthopaedic department and to ascertain whether plain radiograph imagining would be more beneficial prior to an MRI scan. Method. A retrospective review of all referrals received by the hospital over a 6-month period was performed. Patients with knee pain that underwent an MRI scan were classified into two age groups, under 50 years and over 50 years old. Patients having undergone Magnetic resonance imaging (MRI) prior to referral were identified, and findings of the scan were recorded. These patients were reviewed further to see if a plain radiograph had been completed prior to or after the MRI. Results. A total of 414 patients were referred. In the over 50's 228 MRI scans were performed. Of these 103/228 patients the predominate finding was meniscal tears and 72/228 had a finding of osteoarthritis. A plain radiograph of the knee was completed 99/228 cases, 28/99 before the MRI. In the under 50's 186 scans were performed and of these 85/186 the predominate finding was meniscal tears. A plain radiograph of the knee was completed in only eighty-three (83/186) cases, (69/83) before the MRI. Conclusion. In over 50s, 57% of patients (129 of 228) did not have a knee X-ray before having an MRI. For a single hospitals referral over 6 months these unnecessary MRI of knee cost the National Health Services £7,500

Introduction. There are nearly 500,000 people with undiagnosed diabetes mellitus in the UK. The incidental finding vascular calcification on plain radiographs in patients with undiagnosed diabetes has the potential to alter patient management in those presenting with pathology. We hypothesised that the presence of vascular calcification on plain radiographs of the foot may predict the diagnosis of diabetes. The primary aim of this case control study was to determine the positive predictive value of vascular calcification to diagnose diabetes. Secondary aims were to determine the odds of having diabetes dependent on other known risk factors for calcification. Methods. A retrospective case control study of 130 diabetic patients were compared to 130 non-diabetic patients that were matched for age and gender. The presence of vascular calcification in anterior, posterior or plantar vessels, and length of calcification were measured on plain radiographs. McNemar's Chi-squared test and positive predictive values were calculated. Conditional logistic regression models were used to estimate the association between calcification and diabetes. Results. 28 patients had type I diabetes and 102 had type II diabetes. The mean age was 58.0 in both groups and 31.5% were females. 89.2% of those with diabetes had calcification present, and 23.1% in those without (p < 0.0001). Calcification in two vessels predicts diabetes with a positive predictive value of 91.2% (95% CI 82.1%–100%). The odds ratio for having diabetes is 78 (95% CI: 7.8 – 784) times higher in a person who has calcification in the blood vessels of their foot than in a person without calcification after adjusting for confounders. Conclusion. This study has demonstrated that vascular calcification in 2 vessels is over 90% predictive of a diagnosis of diabetes. This screening test could be used in future clinics when interpreting radiographs, aiding in the diagnosis of diabetes and altering patient management

Aims. The aim of this study was to present the first retrieval analysis findings of PRECICE STRYDE intermedullary nails removed from patients, providing useful information in the post-market surveillance of these recently introduced devices. Methods. We collected ten nails removed from six patients, together with patient clinical data and plain radiograph imaging. We performed macro- and microscopic analysis of all surfaces and graded the presence of corrosion using validated semiquantitative scoring methods. We determined the elemental composition of surface debris using energy dispersive x-ray spectroscopy (EDS) and used metrology analysis to characterize the surface adjacent to the extendable junctions. Results. All nails were removed at the end of treatment, having achieved their intended lengthening (20 mm to 65 mm) and after regenerate consolidation. All nails had evidence of corrosion localized to the screw holes and the extendable junctions; corrosion was graded as moderate at the junction of one nail and severe at the junctions of five nails. EDS analysis showed surface deposits to be chromium rich. Plain radiographs showed cortical thickening and osteolysis around the junction of six nails, corresponding to the same nails with moderate – severe junction corrosion. Conclusion. We found, in fully united bones, evidence of cortical thickening and osteolysis that appeared to be associated with corrosion at the extendable junction; when corrosion was present, cortical thickening was adjacent to this junction. Further work, with greater numbers of retrievals, is required to fully understand this association between corrosion and bony changes, and the influencing surgeon, implant, and patient factors involved. Cite this article: Bone Jt Open 2021;2(8):599–610

When treating periprosthetic femur fractures (PPFFs) around total hip arthroplasty (THA)], determining implant fixation status preoperatively is important, since this guides treatment regarding ORIF versus revision. The purpose of this study was to determine the accuracy of preoperative implant fixation status determination utilizing plain films and CT scans. Twenty-four patients who underwent surgery for Vancouver B type PPFF were included in the study. Two joint surgeons and two traumatologists reviewed plain films alone and made a judgment on fixation status. They then reviewed CT scans and fixation status was reassessed. Concordance and discordance were recorded. Interobserver reliability was assessed using Kendall's W and intraobserver reliability was assessed using Cohen's Kappa. Ultimately, the “correct” response was determined by intraoperative findings, as we routinely test the component intraoperatively. Fifteen implants were found to be well-fixed (63%) and 9 were loose. Plain radiographs alone predicted correct fixation status in 53% of cases. When adding the CT data, the correct prediction only improved to 55%. Interestingly, concordance between plain radiographs and CT was noted in 82%. In concordant cases, the fixation status was found to be correct in 55% of cases. Of the 18% of cases with discordance, plain films were correct in 43% of cases, and the CT was correct in 57%. Interobserver reliability demonstrated poor agreement on plain films and moderate agreement on CT. Intraobserver reliability demonstrated moderate agreement on both plain films and CT. The ability to determine fixation status for proximal PPFFs around uncemented femoral components remains challenging. The addition of routine CT scanning did not significantly improve accuracy. We recommend careful intraoperative testing of femoral component fixation with surgical dislocation if necessary, and the surgeon should be prepared to revise or fix the fracture based on those findings

It is unclear whether patients with early radiographic osteoarthritis (OA) but severe hip symptoms benefit from total hip replacement (THR). We aimed to assess which factors were associated with successful THR in this patient group. From a consecutive series of 1,935 patients undergoing THR we identified 70 (3.6%) patients with early OA (Kellgren and Lawrence (KL) grades 0-2). These were compared with 200 patients with advanced OA (KL grades 3–4). Outcomes were Oxford Hip Scores (OHS), EQ5D and EQ-VAS scores; compared pre-operatively with one year post-operatively. We investigated which clinical and radiographic (plain x-ray, CT, MRI) features predicted successful THR in the early OA group. Success was defined as reaching a postoperative OHS≥42. The early OA group were significantly younger (61 vs 66 years; P=0.0035). There were no significant differences in body mass index, ASA grade or gender. After adjusting for confounders, the advanced OA group had a significantly greater percentage of possible change (PoPC) in OHS (75.8% versus 50.4%; P<0.0001) and improvement in EQ5D (0.151 versus 0.002; P<0.0001). There were no significant differences in complication, revision or readmission rates. In the early OA group, we identified 16/70 (22.9%) patients who had a ‘successful’ THR. Of those with early OA, 38 patients had pre-operative CT or MRI scans. Patients who had a ‘successful’ THR were significantly more likely to have subchondral cysts on CT/MRI (91.7% versus 57.7%; P=0.0362). The presence of cysts on CT/MRI was associated with a significantly greater PoPC in OHS (61.6% versus 38.2%; P=0.0353). The combination of cysts and joint space width (JSW) <1mm was associated with a PoPC of 68%. Plain radiographs were found to significantly underestimate the narrowest JSW compared to CT/MRI (2.4mm versus 1.0mm; P<0.0001). We advise caution in performing THRs in patients with early OA (KL grades 0-2) on plain radiographs. We advocate pre-operative cross-sectional imaging (CT or MRI) in these patients. In the absence of cysts on cross-sectional imaging, a THR seems unlikely to provide a satisfactory outcome

Aims. The aim of this study was to report the patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia (TIO) to allow the early diagnosis of this rare condition. Methods. The study included 33 patients with TIO who were treated between January 2000 and June 2022. The causative tumour was detected in all patients. We investigated the symptoms and evaluated the radiological patterns of insufficiency fractures of the rib, spine, and limbs. Results. The mean age of the patients was 57 years (24 to 87), and the mean duration of pain from onset to time of presentation was 3.9 years (0.75 to 23). The primary symptoms were low back pain (ten patients), chest wall pain (eight patients), and hip pain (eight patients). There were symptoms at more sites at the time of presentation compared with that at the time of the onset of symptoms. Bone scans showed the uptake of tracer in the rib (100%), thoracic and lumbar vertebrae (83%), proximal femur (62%), distal femur (66%), and proximal tibia (72%). Plain radiographs or MRI scans identified femoral neck fractures in 14 patients, subchondral insufficiency fractures of the femoral head and knee in ten and six patients, respectively, distal femoral fractures in nine patients, and proximal tibial fractures in 12 patients. Thoracic or lumbar vertebral fractures were identified in 23 of 29 patients (79.3%) when using any imaging study, and a biconcave deformity was the most common type of fracture. Conclusion. Insufficiency fractures in patients with TIO caused spinal pain, chest wall pain, and periarticular pain in the lower limbs. Vertebral fractures tended to be biconcave deformities, and periarticular fractures of the hips and knees included subchondral insufficiency fractures and epiphyseal or metaphyseal fractures. In patients with a tumour, the presence of one or more of these symptoms and an insufficiency fracture should suggest the diagnosis of TIO. Cite this article: Bone Joint J 2023;105-B(5):568–574

The August 2023 Research Roundup. 360. looks at: Can artificial intelligence improve the readability of patient education materials?; What is the value of radiology input during a multidisciplinary orthopaedic oncology conference?; Periprosthetic joint infection in patients with multiple arthroplasties; Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies Project - Phase III outcomes; Knot tying in arthroplasty and arthroscopy causes lesions to surgical gloves: a potential risk of infection; Vascular calcification of the ankle in plain radiographs equals diabetes mellitus?

The June 2023 Foot & Ankle Roundup. 360. looks at: Nail versus plate fixation for ankle fractures; Outcomes of first ray amputation in diabetic patients; Vascular calcification on plain radiographs of the ankle to diagnose diabetes mellitus; Elderly patients with ankle fracture: the case for early weight-bearing; Active treatment for Frieberg’s disease: does it work?; Survival of ankle arthroplasty; Complications following ankle arthroscopy

Aims. The evidence demonstrating the superiority of early MRI has led to increased use of MRI in clinical pathways for acute wrist trauma. The aim of this study was to describe the radiological characteristics and the inter-observer reliability of a new MRI based classification system for scaphoid injuries in a consecutive series of patients. Methods. We identified 80 consecutive patients with acute scaphoid injuries at one centre who had presented within four weeks of injury. The radiographs and MRI scans were assessed by four observers, two radiologists, and two hand surgeons, using both pre-existing classifications and a new MRI based classification tool, the Oxford Scaphoid MRI Assessment Rating Tool (OxSMART). The OxSMART was used to categorize scaphoid injuries into three grades: contusion (grade 1); unicortical fracture (grade 2); and complete bicortical fracture (grade 3). Results. In total there were 13 grade 1 injuries, 11 grade 2 injuries, and 56 grade 3 injuries in the 80 consecutive patients. The inter-observer reliability of the OxSMART was substantial (Kappa = 0.711). The inter-observer reliability of detecting an obvious fracture was moderate for radiographs (Kappa = 0.436) and MRI (Kappa = 0.543). Only 52% (29 of 56) of the grade 3 injuries were detected on plain radiographs. There were two complications of delayed union, both of which occurred in patients with grade 3 injuries, who were promptly treated with cast immobilization. There were no complications in the patients with grade 1 and 2 injuries and the majority of these patients were treated with early mobilization as pain allowed. Conclusion. This MRI based classification tool, the OxSMART, is reliable and clinically useful in managing patients with acute scaphoid injuries. Cite this article: Bone Jt Open 2022;3(11):913–920

Aims. A borderline dysplastic hip can behave as either stable or unstable and this makes surgical decision making challenging. While an unstable hip may be best treated by acetabular reorientation, stable hips can be treated arthroscopically. Several imaging parameters can help to identify the appropriate treatment, including the Femoro-Epiphyseal Acetabular Roof (FEAR) index, measured on plain radiographs. The aim of this study was to assess the reliability and the sensitivity of FEAR index on MRI compared with its radiological measurement. Patients and Methods. The technique of measuring the FEAR index on MRI was defined and its reliability validated. A retrospective study assessed three groups of 20 patients: an unstable group of ‘borderline dysplastic hips’ with lateral centre edge angle (LCEA) less than 25° treated successfully by periacetabular osteotomy; a stable group of ‘borderline dysplastic hips’ with LCEA less than 25° treated successfully by impingement surgery; and an asymptomatic control group with LCEA between 25° and 35°. The following measurements were performed on both standardized radiographs and on MRI: LCEA, acetabular index, femoral anteversion, and FEAR index. Results. The FEAR index showed excellent intraobserver and interobserver reliability on both MRI and radiographs. The FEAR index was more reliable on radiographs than on MRI. The FEAR index on MRI was lower in the stable borderline group (mean -4.2° (. sd. 9.1°)) compared with the unstable borderline group (mean 7.9° (. sd. 6.8°)). With a FEAR index cut-off value of 2°, 90% of patients were correctly identified as stable or unstable using the radiological FEAR index, compared with 82.5% using the FEAR index on MRI. The FEAR index was a better predictor of instability on plain radiographs than on MRI. Conclusion. The FEAR index measured on MRI is less reliable and less sensitive than the FEAR index measured on radiographs. The cut-off value of 2° for radiological FEAR index predicted hip stability with 90% probability. Cite this article: Bone Joint J 2019;101-B:1578–1584

The Ottawa Rules were developed in 1992 by Stiell et al. to “assist clinicians in being more selective in their use of radiography” in suspected ankle fractures. They have a sensitivity of almost 100% and should reduce the number of unnecessary radiographs by 30–40%. We aimed to determine the application of the Ottawa Rules in ankle plain radiograph requests in Accident and Emergency (A&E) and determine the number of unnecessary plain radiographs requests. We carried out a retrospective analysis of 366 ankle plain radiographs, request forms and reports, in A&E over 3 months. We implemented a reminder on the electronic requesting system to prompt clinicians to apply the Ottawa rules and analysed a further 226 scans over the next month. Unnecessary scans were calculated by determining the false negatives. i.e. requests did not fulfil Ottawa Rules and scan showed no fracture. Of the 336 original requests, 45% fulfilled the Ottawa Rules and 43% of all scans were unnecessary. Following our intervention, only 42% of requested scans fulfilled the Ottawa rules and 52% were unnecessary. We concluded that Ottawa rules are knowingly not applied in A&E. Reasons may include low cost and ease of scan, patient and clinician reassurance and perceived low risk of scanning. There are a huge number of unnecessary ankle plain radiographs and soft interventions do not impact on this. We have implemented a simplified version of the text reminder and are re-auditing the data

Aims. Radiostereometric analysis (RSA) is the most accurate radiological method to measure in vivo wear of highly cross-linked polyethylene (XLPE) acetabular components. We have previously reported very low wear rates for a sequentially irradiated and annealed X3 XLPE liner (Stryker Orthopaedics, USA) when used in conjunction with a 32 mm femoral heads at ten-year follow-up. Only two studies have reported the long-term wear rate of X3 liners used in conjunction with larger heads using plain radiographs which have poor sensitivity. The aim of this study was to measure the ten-year wear of thin X3 XLPE liners against larger 36 or 40 mm articulations with RSA. Methods. We prospectively reviewed 19 patients who underwent primary cementless THA with the XLPE acetabular liner (X3) and a 36 or 40 mm femoral head with a resultant liner thickness of at least 5.8 mm. RSA radiographs at one week, six months, and one, two, five, and ten years postoperatively and femoral head penetration within the acetabular component were measured with UmRSA software. Of the initial 19 patients, 12 were available at the ten-year time point. Results. The median proximal, 2D, and 3D wear rates calculated between one and ten years were all less than 0.005 mm/year, with no patient recording a proximal wear rate of more than 0.021 mm/year. Importantly, there was no increase in the wear rate between five and ten years. Conclusion. The very low wear rate of X3 XLPE liners with larger articulations remains encouraging for the future clinical performance of this material. Cite this article: Bone Jt Open 2023;4(11):839–845

Aims. It has been well documented in the arthroplasty literature that lumbar degenerative disc disease (DDD) contributes to abnormal spinopelvic motion. However, the relationship between the severity or pattern of hip osteoarthritis (OA) as measured on an anteroposterior (AP) pelvic view and spinopelvic biomechanics has not been well investigated. Therefore, the aim of the study is to examine the association between the severity and pattern of hip OA and spinopelvic motion. Methods. A retrospective chart review was conducted to identify patients undergoing primary total hip arthroplasty (THA). Plain AP pelvic radiographs were reviewed to document the morphological characteristic of osteoarthritic hips. Lateral spine-pelvis-hip sitting and standing plain radiographs were used to measure sacral slope (SS) and pelvic femoral angle (PFA) in each position. Lumbar disc spaces were measured to determine the presence of DDD. The difference between sitting and standing SS and PFA were calculated to quantify spinopelvic motion (ΔSS) and hip motion (ΔPFA), respectively. Univariate analysis and Pearson correlation were used to identify morphological hip characteristics associated with changes in spinopelvic motion. Results. In total, 139 patients were included. Increased spinopelvic motion was observed in patients with loss of femoral head contour, cam deformity, and acetabular bone loss (all p < 0.05). Loss of hip motion was observed in patients with loss of femoral head contour, cam deformity, and acetabular bone loss (all p < 0.001). A decreased joint space was associated with a decreased ΔPFA (p = 0.040). The presence of disc space narrowing, disc space narrowing > two levels, and disc narrowing involving the L5–S1 segment were associated with decreased spinopelvic motion (all p < 0.05). Conclusion. Preoperative hip OA as assessed on an AP pelvic radiograph predicts spinopelvic motion. These data suggest that specific hip osteoarthritic morphological characteristics listed above alter spinopelvic motion to a greater extent than others. Cite this article: Bone Joint J 2023;105-B(5):496–503

During a periacetabular osteotomy (PAO), intra-operative assessment of correction of acetabular parameters is typically performed using fluoroscopy of the hip, a technique that has not been shown to produce predictable measurements. Furthermore, paralysing agents are used in order to facilitate dissection and fragment mobilization. The effect of paralysing agents on spino-pelvic posture is yet to be investigated. This study aims to: 1. Compare the reliability of intra-operative x-rays versus hip fluoroscopy in the assessment of acetabular fragment correction and 2. Evaluate the effect of changes in spino-pelvic alignment on the assessment of acetabular correction. An IRB approved, retrospective review of all patients who underwent a PAO at our institution between 2006–2018 was performed. Patient demographic data was collected and all available imaging studies were retrieved. Patients were excluded if there was no available to review intra-operative AP pelvis x-ray or intra-operative fluoroscopic PA image of the hip. Using a validated hip analysis software (Hip2Norm), the lateral center edge angle (LCEA) and acetabular index (AI) of plain radiographs were measured. The sacro-femoral-pubic angle (SFP), along with the LCEA and AI of the fluoroscopic image were measured using ImageJ. A oneway ANOVA was used to detect differences between measured parameters in the intra-operative x-ray, the post-operative x-ray and the fluoroscopic image. A total of 93 patients were identified. 26 patients were excluded due to missing data. The mean LCEA in the post-operative, intra-operative, and fluoroscopic groups were as follows: 33.67° (range 5.3° to 52.4°), 30.71°(range 9° to 55.6°), and 29.23°(range 12.4° to 51.4°) respectively. The mean AI in the post-operative, intra-operative, and fluoroscopic groups were as follows: −0.65° (range −18.10° to 27.30°), 0.35°(range −16.10° to 17.20°), and 5.54°(range −11.66° to 27.83°) respectively. When comparing intra-operative to post-operative plain radiographs, there was no statistically significant difference in AI (ΔAI −1±1.29° p=0.71) or LCEA (ΔLCEA 2.95±1.38° p=0.09). When comparing fluoroscopy to post-operative plain radiographs, there was a statistically significant difference in AI (ΔAI −6.21±1.29° p < 0 .0001) as well as LCEA (ΔLCEA 4.44±1.38° p < 0 .0001). Statistical analysis revealed no influence of demographics (age, BMI, gender), on acetabular correction parameters. The mean SPF angles measured from intra-operative and post-operative x-rays were 69.32±5.11° and 70.45±5.52°. There was a statistically significant difference between these 2 measurements with a ΔSFP of 1.03° (p < 0 .0001). The results of our study show that the use of intra-operative x-ray for the assessment of LCEA and AI is more reliable than fluoroscopic images. Further, we found a difference in SFP angle, which offers an indirect assessment of pelvic tilt, between the intra-operative and the post-operative plain x-rays. This suggests that there are changes in pelvic tilt during the surgery, which can be attributed to either patient positioning or changes in spino-pelvic posture secondary to the paralysing agents used by the anesthetists. The use of intra-operative x-rays as well as the effect of paralysing agents on spino-pelvic alignment should be considered by surgeons performing PAO's

We describe the routine imaging practices of Level 1 trauma centres for patients with severe pelvic ring fractures, and the interobserver reliability of the classification systems of these fractures using plain radiographs and three-dimensional (3D) CT reconstructions. Clinical and imaging data for 187 adult patients (139 men and 48 women, mean age 43 years (15 to 101)) with a severe pelvic ring fracture managed at two Level 1 trauma centres between July 2007 and June 2010 were extracted. Three experienced orthopaedic surgeons classified the plain radiographs and 3D CT reconstruction images of 100 patients using the Tile/AO and Young–Burgess systems. Reliability was compared using kappa statistics. A total of 115 patients (62%) had plain radiographs as well as two-dimensional (2D) CT and 3D CT reconstructions, 52 patients (28%) had plain films only, 12 (6.4%) had 2D and 3D CT reconstructions images only, and eight patients (4.3%) had no available images. The plain radiograph was limited to an anteroposterior pelvic view. Patients without imaging, or only plain films, were more severely injured. A total of 72 patients (39%) were imaged with a pelvic binder in situ. Interobserver reliability for the Tile/AO (Kappa 0.10 to 0.17) and Young–Burgess (Kappa 0.09 to 0.21) was low, and insufficient for clinical and research purposes. Severe pelvic ring fractures are difficult to classify due to their complexity, the increasing use of early treatment such as with pelvic binders, and the absence of imaging altogether in important patient sub-groups, such as those who die early of their injuries. Cite this article: Bone Joint J 2013;95-B:1396–1401

We evaluated the impact of stereo-visualisation of three-dimensional volume-rendering CT datasets on the inter- and intraobserver reliability assessed by kappa values on the AO/OTA and Neer classifications in the assessment of proximal humeral fractures. Four independent observers classified 40 fractures according to the AO/OTA and Neer classifications using plain radiographs, two-dimensional CT scans and with stereo-visualised three-dimensional volume-rendering reconstructions. Both classification systems showed moderate interobserver reliability with plain radiographs and two-dimensional CT scans. Three-dimensional volume-rendered CT scans improved the interobserver reliability of both systems to good. Intraobserver reliability was moderate for both classifications when assessed by plain radiographs. Stereo visualisation of three-dimensional volume rendering improved intraobserver reliability to good for the AO/OTA method and to excellent for the Neer classification. These data support our opinion that stereo visualisation of three-dimensional volume-rendering datasets is of value when analysing and classifying complex fractures of the proximal humerus

Purpose: To compare the accuracy of post-operative plain radiographs versus computed tomography (CT) scans for the assessment of acetabular fracture reduction. Method: A retrospective assessment of sixty-four fractures in sixty-two patients was performed independently by three orthopedic trauma surgeons. Pre-operative CT scans and three plain radiographs (one anteroposterior pelvis and two Judet views) were used to classify the fracture pattern and measure pre-operative articular step and gap. Post-operative reduction quality was assessed using three plain radiographs and an axial CT assessing for step, gap, intra-articular hardware or fragments and necessity to re-operate. Results: Fracture patterns were as follows; posterior wall (n=10), posterior column (n=1), anterior wall (n=4), anterior column (n=1), transverse (n=12), posterior column posterior wall (n=4), transverse posterior wall (n=8), T-type (n=6), anterior column posterior hemi-transverse (n=5) and associated both column (n=11). Pre-operatively, the average step and gap on plain radiographs was 8.7 mm (±SD) and 15.3 mm (±SD). Post-operatively, the average step and gap was 0.6 mm (SD) and 0.9 mm (SD) based on 46 patients. The assessment was not possible in 18 patients due to overlying hardware. Using plain radiographs, one patient was found to have an inadequate reduction (> 2mm step and/or > 3mm gap). Post-operative measurement of step and gap by CT scan were 1.2 mm (SD) and 2.3 mm (SD) respectively. Using CT scans, eight patients were found to have either an inadequate reduction, intra-articular hardware or retained fragments. Computed tomography demonstrated 2 times more step and gap compared to plain radiographs. Conclusion: Post-operative CT was found to be more sensitive than plain radiographs to assess the quality of acetabular fracture reduction. Plain radiographs detected only 1 out of 8 cases where further operative intervention may have been beneficial. Given the consequences of missing an unacceptable reduction, intra-articular hardware, or retained intra-articular fragments, it is recommended that all fractures should be assessed postoperatively with CT unless the patient is not a candidate for further surgery for reasons independent of reduction quality. The benefits of post-operative CT imaging in acetabular fractures likely outweigh the cost and radiation exposure associated with its use

Introduction. The stability of the elbow joint following an acute elbow dislocation is dependent on associated injuries. The ability to identify these concomitant injuries correctly directs management and improves the chances of a successful outcome. Interpretation of plain radiographs in the presence of either a dislocation or post-reduction films with plaster in-situ is difficult. This study aimed to assess the ability of orthopaedic registrars to accurately identify associated bony injuries on initial plain radiographs using CT as the gold standard for comparison. Methods. Patients over the age of 16 years undergoing an elbow CT scan within one week of a documented elbow dislocation between 1st June 2010 and 1st June 2014 were included in the study. Three orthopaedic registrars independently reviewed both the initial dislocation and immediate post reduction plain radiographs to identify any associated bony injuries. This radiograph review was repeated by each registrar after two weeks. The incidence of associated injuries as well as the inter- and intra-observer variability was calculated. Results. 28 patients were included in the study. 54% of the patients were female and the mean age was 45 years (range 16 to 90 years). The incidence of a radial head fracture was 54%, coronoid fracture 43% and epicondyle avulsion 18% on CT. The inter-observer reliability was only shown to be fair amongst registrars and the intra-observer variability moderate. Conclusions. Computerised tomography is a useful adjunct in the assessment of associated osseous injuries following an elbow dislocation due to the presence of a high number of injuries. Plain radiographs alone have been shown to have only a fair and moderate inter and intra-observer variability respectively, therefore a low threshold to obtain further 3D imaging should be practised. Level of Evidence. IV

Aims. Given the possible radiation damage and inaccuracy of radiological investigations, particularly in children, ultrasound and superb microvascular imaging (SMI) may offer alternative methods of evaluating new bone formation when limb lengthening is undertaken in paediatric patients. The aim of this study was to assess the use of ultrasound combined with SMI in monitoring new bone formation during limb lengthening in children. Methods. In this retrospective cohort study, ultrasound and radiograph examinations were performed every two weeks in 30 paediatric patients undergoing limb lengthening. Ultrasound was used to monitor new bone formation. The number of vertical vessels and the blood flow resistance index were compared with those from plain radiographs. Results. We categorized the new bone formation into three stages: stage I (early lengthening), in which there was no obvious callus formation on radiographs and ultrasound; stage II (lengthening), in which radiographs showed low-density callus formation with uneven distribution and three sub-stages could be identified on ultrasound: in Ia punctate callus was visible; in IIb there was linear callus formation which was not yet connected and in IIc there was continuous linear callus. In stage III (healing), the bone ends had united, the periosteum was intact, and the callus had disappeared, as confirmed on radiographs, indicating healed bone. A progressive increase in the number of vertical vessels was noted in the early stages, peaking during stages IIb and IIc, followed by a gradual decline (p < 0.001). Delayed healing involved patients with a prolonged stage IIa or those who regressed to stage IIa from stages IIb or IIc during lengthening. Conclusion. We found that the formation of new bone in paediatric patients undergoing limb lengthening could be reliably evaluated using ultrasound when combined with the radiological findings. This combination enabled an improved assessment of the prognosis, and adjustments to the lengthening protocol. While SMI offered additional insights into angiogenesis within the new bone, its role primarily contributed to the understanding of the microvascular environment rather than directly informing adjustments of treatment. Cite this article: Bone Joint J 2024;106-B(7):751–758

Introduction: The purpose of this study was to evaluate the impact of volume rendering 3D computed tomography reconstructions on the inter- and intraobserver reliability of the OTA/AO and Neer classifications in the assessment of proximal humerus fractures. Material and Methods: Four observers with different levels of clinical training classified forty proximal humerus fractures according to the OTA/AO and Neer classifications. Three rounds of evaluation were performed and compared. First, fractures were classified on the basis of plain radiographs alone. Then, four weeks later, the combination of plain radiographs and computed tomography scans with conventional 3D SSD reconstructions was evaluated. Finally, four weeks later, the combination of plain radiographs, computed tomography scans, and 3D volume rendering reconstructions was assessed. These readings were repeated in a newly randomized order after an interval of twelve weeks to evaluate intraobserver reliability. Results: Interobserver reliability for the AO/ASIF classification showed good interobserver reliability with plain radiographs (k=0,65) and two-dimensional CT scans with conventional three-dimensional (SSD) reconstructions (k=0,71). Interobserver reliability improved to excellent when the fractures were classified on the basis of 3D volume rendering reconstructions scans (k=0,84). Intraobserver reliability of the OTA/AO classification was good with plain radiographs (k=0,70) and improved to excellent after adding three-dimensional SSD reconstructions (k=0,80) and three-dimensional VR reconstructions (k=0,88). Interobserver reliability of the Neer classification was poor with plain radiographs (k=0,39) and moderate with two-dimensional CT scans and conventional three-dimensional (SSD) reconstructions (k=0,56) and improved to good with the addition of 3D VR scans (k=0,74). Intraobserver reliability for was poor with plain radiographs (k=0,34), good with three-dimensional SSD reconstructions (k=0,61), and excellent with three-dimensional VR reconstructions (k=0,80). Conclusion: In this study, three-dimensional volume rendering computed tomography improved the inter- and intraobserver reliability of the AO/OTA and the Neer classifications in the assessment of proximal humerus fractures. In the opinion of the authors, 3D volume rendering CT-scans are a helpful tool for preoperative planning and classification of fractures of the proximal humerus

Aims. Slipped upper femoral epiphysis (SUFE) has well documented biochemical and mechanical risk factors. Femoral and acetabular morphologies seem to be equally important. Acetabular retroversion has a low prevalence in asymptomatic adults. Hips with dysplasia, osteoarthritis, and Perthes’ disease, however, have higher rates, ranging from 18% to 48%. The aim of our study was to assess the prevalence of acetabular retroversion in patients presenting with SUFE using both validated radiological signs and tomographical measurements. Methods. A retrospective review of all SUFE surgical cases presenting to the Royal Children’s Hospital, Melbourne, Australia, from 2012 to 2019 were evaluated. Preoperative plain radiographs were assessed for slip angle, validated radiological signs of retroversion, and standardized postoperative CT scans were used to assess cranial and mid-acetabular version. Results. In all, 116 SUFEs presented in 107 patients who underwent surgical intervention; 47 (52%) were male, with a mean age of 12.7 years (7.5 to 16.6). Complete radiological data was available for 91 patients (99 hips) with adequate axial CT imaging of both hips. Overall, 82 patients (82%) underwent pinning in situ (PIS), with subcapital realignment surgery (SRS) performed in 17 patients (18%) (slip angles > 75°). Contralateral prophylactic PIS was performed in 72 patients (87%). On the slip side, 62 patients (68%) had one or more radiological sign of retroversion. Tomographical acetabular retroversion was more pronounced cranially than caudally of the acetabulum on both the affected side and the contralateral side (p < 0.001) as expected in the normal population. Increasing severity of the slip was found to be directly proportional to the degree of reduction in cranial and central acetabular version (p < 0.05) in the SUFE hips. Conclusion. Acetabular retroversion is more prevalent in patients with SUFE than previously reported, and have been shown be correlated to the severity of the slip presentation. The presence of radiological signs of acetabular retroversion could be used to justify prophylactic contralateral pinning. Cite this article: Bone Jt Open 2022;3(2):158–164

INTRODUCTION. Recently, as the number of total knee arthroplasty (TKA) is increasing, the number of revision TKA due to loosening or osteolysis is rapidly increasing. Large bone defect is one of the most critical issues during revision TKA. Therefore, early detection of bone loss around the TKA prosthesis before bone loss has been enlarged is very important. However, it is difficult to detect the loosening or ostolysis at the early stage around the femoral component even using fluoroscopically guided plain radiograph. A novel technique of tomography (Tomosynthesis; Shimazu Corporation, Kyoto, Japan) was introduced to detect the small bone loss. The purpose of this study was to examine, in a pig model of radiolucent line and osteolysis around TKA, the sensitivity and specificity of detection of radiolucent line and osteolysis using fluoroscopically guided plain radiographs and a novel technique of tomography. METHODS. Six cemented femoral components (PFC Sigma; DePuy, Warsaw, IN, USA) were implanted in pig knees. Two components were implanted with standard cement technique (Standard model). Two components were implanted with 2 mm-thick defect between the cement and bone (Radiolucent line model). Two components were implanted with cystic defects (mean size = 0.7 cm. 3. ) in femoral condyles (Osteolysis model). The simulated bone lesions were filled with agarose to simulate granuloma tissue and to reduce the air artifact around the bone lesions, which can interfere with imaging techniques (Figure 1). Fluoroscopically guided plain radiographs (63 kV, 360 mA, 50 msec) were taken in 4 postures (antero-posterior, lateral, and +/−45 degrees oblique views) for each specimen (Figure 2). For Tomosynthesis, 74 frames were acquired in the rate 30 frames/sec with fixed X-ray condition (65 kV 1.25 mAs) and were reconstructed (Figure 3). Seven blinded assessors experienced in clinical radiographic analysis examined. The sensitivities, specificities and accuracy of the two imaging techniques were compared. RESULTS. The mean sensitivity and specificity of Tomosynthesis were 85.4% and 87.2% (Table 1). Any bone defects (radiolucent lines or osteolysis) were not detected using fluoroscopically guided plain radiographs, because metal box for post-cam mechanism hinder the bone defect around the femoral condyles. DISCUSSION. This study demonstrates the uselessness of fluoroscopically guided plain radiographs for small bone defect around the femoral component. Tomosynthesis, a novel technique of tomography, showed much higher efficacy comparing to conventional fluoroscopically guided plain radiographs. Although the size of bone defect in this study (0.7 cm. 3. ) was much smaller than previous report (1.4 cm. 3. ) using CT (Solomon L, et al., J Arthroplasty in press), sensitivity of this study was higher than that of previous study using CT (75%). Tomosynthesis will be useful method for early detection of small periprosthetic bone defects around femoral component of TKA

Introduction. Osteomyelitis is a challenge in diagnosis and treatment. 18F-FDG PET-CT provides a non-invasive tool for diagnosing and localizing osteomyelitis with a sensitivity reaching 94% and specificity reaching 100%. We aimed to assess the agreement in identifying the geographic area of infected bone and planned resection on plain X-ray versus 18F-FDG PET-CT. Materials & Methods. Clinical photos and X-rays of ten osteomyelitis patients were shown to ten consultant surgeons; they were asked to draw the area of infection and extent of planned surgical debridement; data will be compared to 18F-FDG PET-CT results. Results. We tested the agreement between the surgeons in every parameter. Regarding height, there was poor agreement between surgeons. Regarding perimeter, the ten surgeons showed low-moderate agreement. The ten surgeons showed a low-moderate agreement for circularity. Results document the variability of assessment and judgement based on plain X-rays. In comparison to PET-CT, All parameters were significantly different in favour of 18F-FDG PET-CT over X-ray (P < 0.001). Conclusions. 18F FDG PET-CT provides a three-dimensional tool for localizing the exact location of the infected bone and differentiating it from the normal bone. Thus, it could be beneficial in precise pre-operative planning and surgical debridement of chronic osteomyelitis

The reverse total shoulder replacement (rTSR) has excellent clinical outcomes and prosthesis longevity, and thus, the indications have expanded to a younger age group. The use of a stemless humeral implant has been established in the anatomic TSR; and it is postulated to be safe to use in rTSR, whilst saving humeral bone stock for younger patients. The Lima stemless rTSR is a relatively new implant, with only one paper published on its outcomes. This is a single-surgeon retrospective matched case control study to assess short term outcomes of primary stemless Lima SMR rTSR with 3D planning and Image Derived Instrumentation (IDI), in comparison to a matched case group with a primary stemmed Lima SMR rTSR with 3D planning and IDI. Outcomes assessed: ROM, satisfaction score, PROMs, pain scores; and plain radiographs for loosening, loss of position, notching. Complications will be collated. Patients with at least 1 year of follow-up will be assessed. With comparing the early radiographic and clinical outcomes of the stemless rTSR to a similar patient the standard rTSR, we can assess emerging trends or complications of this new device. 41 pairs of stemless and standard rTSRs have been matched, with 1- and 2-year follow up data. Data is currently being collated. Our hypothesis is that there is no clinical or radiographical difference between the Lima stemless rTSR and the traditional Lima stemmed rTSR

Periprosthetic osteolysis is a serious medium to long-term complication of total hip arthroplasty. Interobserver reliability of detecting osteolysis around cementless ace-tabular components is reported to be poor using plain radiographs. Quantitative computed tomography (CT) provides sensitive and accurate measures of osteolytic lesion volume, however, there may remain a role for plain radiographs in monitoring progression of osteolysis. The aim of this study was to use quantitative CT to monitor the progression of osteolytic lesions around cementless acetabular components and to compare plain radiographs and CT in determining the progression of osteolysis. A high-resolution multi-slice quantitative CT scanner with metal artefact suppression was used to determine the volume of osteolysis around 18 cementless acetabular components. The mean time since arthroplasty was 14 years (range 10–15 years) at the initial CT. Repeat scans of the hip were undertaken over a five-year period to determine progression of osteolysis with time. A second blinded observer examined anteroposterior and lateral plain radiographs taken at the same time as the CT scans and measured the location and area of osteolytic lesions. CT measurements determined that in ten of 18 hips (56%), osteolytic lesions progressed by more than 1cm3/yr. Progression in size of osteolytic lesions was significantly associated with hips with larger osteolytic lesions at the initial CT (p=0.0005). The mean volume of osteolysis progression was 4.9cm3/year (range 2.8–7.5cm3/yr) for cases with osteolysis volumes greater than 10cm3 at the initial CT, and 0.7cm3/yr (range 0–2.3cm3/yr) for cases with osteolysis volumes smaller than or equal to 10cm3 at the initial CT (p=0.002). Importantly, the rate of osteolysis progression between CT scans varied greatly in some hips. In contrast, using plain radiograph assessment, progression in the area of osteolytic lesions was only detected in 10% of hips. In conclusion, quantitative CT provides new insights into the natural history of periacetabular osteolysis. Total osteolysis volume greater than 10cm3 is associated with a high risk of progression and progress, on average, at a greater rate than those less than 10cm3. Plain radiographs, including a lateral view, are an unreliable clinical diagnostic tool to predict substantial progression of periacetabular osteolytic lesions

Computed tomography (CT) provides a sensitive and accurate measure of periacetabular osteolytic lesion volume, however, there may remain a role for plain radiographs in monitoring osteolysis. This study aimed to compare CT and plain radiographs for determining the progression in size of osteolytic lesions around cementless acetabular components. A high-resolution multi-slice CT scanner with metal artefact suppression was used to determine the volume and progression of osteolysis around 19 cementless Harris Galante-1 and PCA acetabular components. The mean duration since arthroplasty was 14 years (range 10–15 years) at initial CT. Repeat scans of the hip were undertaken over a five year period to determine the progression in size of osteolytic lesions over time. A second blinded observer manually measured the area of osteolytic lesions off anteroposterior pelvis radiographs and oblique radiographs of the acetabulum that were taken at the same time as the CT scan. All 19 hips had CT detected osteolysis. Osteolysis was detected on one or both of the anteroposterior pelvis or oblique radiographs from at least one time point in eight of 19 hips (42%). Osteolysis was detected on 31 of 76 anteroposterior pelvis radiographs (41%) and on 22 of 75 oblique radiographs (29%) (p=0.140). Osteolysis was more likely to be detected on plain radiographs if the lesion volume was greater than 10cm3 in size compared to those 5–10cm3 and less than 5cm3 in size (p=0.009). In 10 of 19 hips (55%), CT determined that osteolytic lesions progressed in size by more than 1cm3/yr. The mean volume of osteolysis progression was 3.2cm3/yr (range 1.1–7.5cm3/yr). Progression in size of osteolytic lesions was significantly associated with hips with larger osteolytic lesions at the initial CT (p=0.0004). Radiographic measurements detected progression of osteolytic lesions in 5 of the 10 hips (50%) that progressed. No correlation was found between progression in size of osteolytic lesions as measured by CT and progression in size of osteolytic lesions as measured off the anteroposterior pelvis (r2 = 0.16, p=0.37), oblique (r2=0.37, p=0.15) and combined anteroposterior pelvis and oblique radiographs (r2=0.34, p=0.17). Periacetabular osteolytic lesions are more likely to be detected on plain radiographs if they are more than 10cm3 in size. Plain radiographs may therefore provide some monitoring value as lesions more than 10cm3 are more likely to be progressive. However, plain radiographs should not be relied upon to monitor the progression of these lesions

Abstract. Cemented total hip arthroplasty (THA) in the younger patient has historically been associated with higher wear and revision rates. We carried out a retrospective study of a prospectively collected database of patients at Wrightington hospital undergoing cemented THA under 55 years of age to determine acetabular wear and revision rates. Between August 2005 and December 2021 a cohort of 110 patients, 56 males and 54 females, underwent Cemented Total Hip Replacement through a posterior approach. Mean age at operation was 50yrs (35–55). The mean follow up was 6 years 9 months (0–16 years). 3 patients were lost to follow-up. Of the remaining 107 patients, Conventional and cross lined polyethylene were used in 54 and 53 patients respectively. Ceramic heads were used in 102 patients. 22.225mm and 28mm heads were used in 60 and 47 patients respectively. Clinical outcomes were assessed by Merle d'Aubigne and Postel scores which showed significant functional improvement. Linear wear was measured on plain radiographs using TRAUMA CAD and cup loosening was assessed by classification of Hodgkinson et al. No cases were revised during the observed follow up period. The mean wear rate in conventional and crosslinked polyethylene cups were 2.31mm (0.1–4.6) and 1.02mm (0.1–2.6) respectively. Cemented THA with both conventional and crosslinked polyethylene provides excellent survival rates in adults under the age of 55 years and crosslinked polyethylene may further improve these results due to improved wear rates

Introduction. The various problems that are managed with circular external fixation (e.g. deformity, complex fractures) also typically require serial plain x-ray imaging. One of the challenges here is that the relatively radio-opaque components of the circular external fixator (e.g. the rings) can obscure the view of the area of interest (e.g. osteotomy site, fracture site). In this presentation we describe how the geometry of the x-ray beam affects the produced image and how we can use knowledge of this to our advantage. Whilst this can be applied to any long bone, we have focused on the tibia, given that it's the most common long bone that is treated by circular external fixation. Materials & Methods. In the first part of the presentation we describe the known attributes (geometry) of the x-ray beam and postulate what effect it would have when we x-ray a long bone that is surrounded by a circular external fixator. In the second part we demonstrate this in practice using a tibia and a 3 ring circular external fixator. Differing x-ray beam orientations are used to demonstrate both how the geometry of the beam affects the produced image and how we can use this to our advantage to better visualise part of the bone. Results. The practical part of the study confirmed the theoretical part. Conclusions. Knowledge of the beam geometry can be used to minimise the obscuring nature of the circular fixator. This technique is simple and can be easily taught to the radiographer. It is a useful adjunct for the limb reconstruction surgeon

Aim. The localization of sequestrum in chronic osteomyelitis (COM) is crucial in preoperative planning. The identification of sequestrum on plain X-ray could be difficult. CT and MRI were reported to show the sequestrum. We aimed to analyze the sequestrum characteristics on 18F-FDG-PET-CT images. Methods. A prospective study included all patients diagnosed with long-bone chronic osteomyelitis. All patients had preoperative 18F-FDG-PET-CT. Images were analyzed using RadiAnt DICOM Viewer. Axial cuts were used to measure the Standard Uptake Ratio (SUV)max in the Region of Interest (ROI) in the sequestrum, the surrounding area, and the normal bone in the same cut. Surgical debridement was done as standard; samples were taken for microbiology and histopathology, and the intraoperative finding was documented. Results. Nineteen patients (17 males/2 females) were operated on in one center between October/2021 and Jan/2023 at a mean age of 32±18. There were 10 tibias, 7 femurs, one ulna, and one fibula. Ten had postoperative COM, six open fractures, and three hematogenous OM. They all showed sequestrum on PET-CT; the dead bone appeared void, surrounded by a halo of increased uptake. There was a trend of lower uptake in the sequestrum compared to the halo around. The mean SUVmax at the sequestrum was 4.18±3.16, compared to the surrounding halo, 7.08±5.81. The normal bone has a mean SUVmax of 1.61±1.42. Sequestrum was removed successfully in all cases. Conclusion. 18F-FDG-PET-CT can precisely localize the sequestrum preoperatively, it has a lower uptake than tissues around it. This would facilitate planning and improve the quality of debridement

Radiological investigations are essential in the work-up of patients presenting with non-arthritic hip pain, to allow close review of the complex anatomy around the hip and proximal femur. The aim of this study is to quantify the radiation exposure associated with common radiological investigations performed in assessing young adult patients presenting with non-arthritic hip pain. A retrospective review of our UK tertiary hip preservation centre institutional imaging database was performed. Data was obtained for antero-posterior, cross-table lateral and frog-lateral radiographs, along with data for the low dose CT hip protocol and the Mako CT Hip protocol. The radiation dose of each imaging technique was measured in terms of dose-area product (DAP) with units of mGycm2, and the effective doses (ED, mSv) calculated. The mean effective radiation dose for hip radiographs was in the range 0.03 to 0.83mSv (mean DLP 126.7–156.2 mGycm2). The mean effective dose associated with the low-dose CT hip protocol was 3.04mSv (416.8 mGycm2) and for the Stryker Mako CT Hip protocol was 8.4mSv (1061 mGycm2). The radiation dose associated with use of CT imaging was significantly greater than plain radiographs (p<0.005). Investigation of non-arthritic hip pain can lead to significant ionising radiation exposure for patients. In our institution, the routine protocol is to obtain an anteroposterior radiograph and then a specific hip sequence 3 Tesla MRI including anteversion views. This provides the necessary information in the majority of cases, with CT scanning reserved for more complex cases where we feel there is a specific indication. We would encourage the hip preservation community to carefully consider and review the use of ionising radiation investigations

Currently, the consensus regarding subscapularis tendon repair during a reverse total shoulder arthroplasty (rTSA) is to do so if it is possible. Repair is thought to decrease the risk of dislocation and improve internal rotation but may also increase stiffness and improvement in internal rotation may be of subclinical benefit. Aim is to retrospectively evaluate the outcomes of rTSA, with or without a subscapularis tendon repair. We completed a retrospective review of 51 participants (25 without and 26 with subscapularis repair) who received rTSR by a single-surgeon using a single-implant. Three patient reported outcome measures (PROM) were assessed pre-operatively and post-operative at twelve months, as well as range of movement (ROM) and plain radiographs. Statistical analysis utilized unpaired t tests for parametric variables and Mann-Whitney U test for nonparametric variables. External Rotation ROM pre-operatively was the only variable with a significance difference (p=0.02) with the subscapularis tendon repaired group having a greater range. Pre- and post-operative abduction (p=0.72 & 0.58), forward flexion (p=0.67 & 0.34), ASES (p=0.0.06 & 0.78), Oxford (p=0.0.27 & 0.73) and post-operative external rotation (p=0.17). Greater external rotation ROM pre-operatively may be indicative of the ability to repair the subscapularis tendon intra-operatively. However, repair does not seem to improve clinical outcome at 12 months. There was no difference of the PROMs and AROMs between the subscapularis repaired and not repaired groups for any of the variables at the pre-operative or 12 month post operative with the exception of the external rotation ROM pre-operatively. We can conclude that from PROM or AROM perspective there is no difference if the tendon is repaired or not in a rTSR and indeed the patients without the repair may have improved outcomes at 12 months

Introduction: The successful outcome from metal-on-metal hip resurfacing is partly dependent on the restoration of the natural biomechanics of the hip joint. Valid measurement of the geometry of the reconstructed hip is challenging using plain radiographs. CT is more accurate and precise yet rarely used to assess hip geometry. Our aims were 1) to quantify the agreement between radiographic and CT measurement of horizontal femoral offset (HFO); 2) to determine the relationship between HFO and patient gender and size; and 3) To compare HFO of the reconstructed hip to the contralateral hip. Method: We used plain radiograph and CT data from 42 patients (23 male and 19 female) from a consecutive series with unilateral metal-on-metal hip resurfacings. We measured HFO of both hips (component and contralateral) using plain radiographs (with PACS) and CT (with Robin 3D software). Pelvic width and radial head sizes were measured on CT. Measurements were made in triplicate by 2 observers. We graded the contralateral hip for severity of joint space narrowing on plain radiographs. Results: There was considerable disagreement between CT and plain radiographs for HFO. HFO was statistically different between genders (p=0.0004). HFO correlated with femoral head radius (0.57, p=0.0002), but not patient size (for height (0.29, p=0.13), or pelvic width (0.25, p=0.11). There was a wide range of HFO of the contralateral hips that was comparable to the reconstructed hip. Conclusion: To our knowledge this is the first study to show the importance of measuring HFO using CT. HFO was found to be correlated to gender and femoral head radius, but not with any other parameters of patient size. The wide range of offset was considerably greater than is available from current total hip replacement designs. Hip resurfacing may overcome this

Abstract. Introduction. High posterior tibial slope (PTS) has been recognised as a risk factor for anterior cruciate ligament rupture and graft failure. This prospective randomised study looked at intra-operative findings of concomitant intra-articular meniscal and chondral injuries during a planned ACL reconstruction. Material and Methods. Prospective data was collected as part of a randomised trial for ACL reconstruction techniques. Intra-operative data was collected and these findings were compared with the PTS measured on plain radiograph by a single person twice through a standardised technique and intra-observer analysis was performed. Results. 49 confirmed ACL rupture patients were in the trial. The average age was 34 (23–66) years and 12 patients were female. 17 patients (34%) had PTS of 12 degrees or more. The intra-observer analysis for PTS measurements in a 2-sided paired T test, showed a mean difference of 0.03 degrees with a P value = 0.83. 23 patients had medial meniscal pathology identified, 15 (65%) had a PTS <12 degrees. 16 patients had lateral meniscus pathology and 9 (56%) had a PTS <12 degrees. Chondral damage did not appear significantly different in the two groups (<12 degrees 15% vs >12 degrees 23%). Conclusion. In this sample, a PTS >12 degrees was not associated with a higher incidence of meniscal or chondral damage after a confirmed ACL rupture

While computed tomography (CT) provides an accurate measure of osteolysis volume, it would be advantageous in general clinical practice if plain radiographs could be used to monitor osteolysis. This study determined the ability of plain radiographs to detect the presence of and determine the progression in size of osteolytic lesions around cementless acetabular components. Nineteen acetabular components were diagnosed with osteolysis using a high-resolution multi-slice CT scanner with metal artefact suppression. Mean duration since arthroplasty was 14 years (range 10–15 years) at initial CT. Repeat CT scans were undertaken over a five year period to determine osteolysis progression. On anteroposterior pelvis (AP) radiographs and oblique radiographs of the acetabulum seen on the rolled lateral hip view, which were taken at the same time as the CT scans, area of osteolysis was measured manually correcting for magnification. Osteolysis was detected on the AP radiographs in 8 of 19 hips (42%), on the oblique radiographs in 6 of 19 hips (32%) and on the combined AP and oblique radiographs in 8 of 19 hips (42%). Throughout the study period, osteolysis was detected on 31 of 76 AP radiographs (41%) and 22 of 75 oblique radiographs (29%). Osteolysis was more likely to be detected on plain radiographs if the lesion volume was greater than 10cm3 in size (p=0.005). On CT, osteolysis progressed by more than 1cm3/yr in 10 of 19 hips (55%). In these ten hips, osteolysis progression was detected on AP radiographs in six hips and on oblique radiographs in three hips. No correlation was found between osteolysis progression measured by CT and that measured on AP (r2=0.16, p=0.37) or oblique (r2=0.37, p=0.15) or AP and oblique radiographs (r2=0.34, p=0.17). Plain radiographs are poor in monitoring progression in size of periacetabular osteolytic lesions. Plain radiographs may detect lesions more than 10cm3 in size, but are unreliable

There is no agreement as to the superiority or specific indications for cast treatment, percutaneous pinning or open fracture fixation for Bennett's fractures of the thumb metacarpal. We undertook this study to compare the outcomes of treatment for patients treated for Bennett's fracture in the medium term. We reviewed 33 patients treated in our unit for a bennett's fracture to the thumb metacarpal with closed reduction and casting. Each patient was matched with a patient treated surgically. Patients were matched for sex, age, Gedda grade of injury and hand dominance. Patients were reviewed at a minimum of 5-years and 66-patients were reviewed in total. Patients were examined clinically and also asked to complete a DASH questionnaire score and the brief Michigan hand questionnaire. Follow up plain radiographs were taken of the thumb and these were reviewed and graded for degenerative change using the Eaton-Littler score. Sixty-six patients were included in the study, with 33 in the surgical and non-surgical cohorts respectively. The average age was 39 years old. In each cohort, 12/33 were female, 19/33 were right-handed with 25% of individuals injuring their dominant hand. In each coort there were 16 Grade 1 fractures, 4 Grade 2 and 13 Grade 3 fractures. There was no difference between the surgically treated and cast-treatment cohorts of patients when radiographic arthritis, pinch grip, the brief Michigan Hand Questionnaire and pain were assessed at final review. The surgical cohort had significantly lower DASH scores at final follow-up. There was no significant difference in the normalised bMHQ scores. Our study was unable to demonstrate superiority of either operative or non-operative fracture stabilization. Patients in the surgical cohort reported superior satisfaction and DASH scores but did not demonstrate any superiority in any other objectively measured domain

Chauffeur fractures or isolated radial styloid fractures (IRSF) are known to be associated with scapholunate ligament (SL) injuries. Diagnosis without arthroscopic confirmation is difficult in acute fractures. Acute management of this injury with early repair may prevent the need for more complex reconstructive procedures for chronic injuries. We investigated if all IRSF should be assessed arthroscopically for concomitant SL injuries. We performed a prospective cohort study on patients above the age of 16, presenting to the Gold Coast University Hospital with an IRSF, over 2 years. Plain radiographs and computerized tomography (CT) scans were performed. All patients had a diagnostic wrist arthroscopy performed in addition to an internal fixation of the IRSF. Patients were followed up for at least 3 months post operatively. SL repair was performed for all Geissler Grade 3/4 injuries. 10 consecutive patients were included in the study. There was no radiographic evidence of SL injuries in all patients. SL injuries were identified arthroscopically in 60% of patients and one third of these required surgical stabilisation. There were no post operative complications associated with wrist arthroscopy. We found that SL injuries occurred in 60% of IRSF and 20% of patients require surgical stabilisation. This finding is in line with the literature where SL injuries are reported in up to 40-80% of patients. Radiographic investigations were not reliable in predicting possible SL injuries in IRSF. However, no SL injuries were identified in undisplaced IRSF. In addition to identifying SL injuries, arthroscopy also aids in assisting and confirming the reduction of these intra-articular fractures. In conclusion, we should have a high index of suspicion of SL injury in IRSF. Arthroscopic assisted fixation should be considered in all displaced IRSF. This is a safe additional procedure which may prevent missed SL injuries and their potential sequelae

Aim: 1. To assess the role of the CT scan in management of intra-articular fractures of the calcaneum. 2. Does the scan makes any difference to the management decision, obtained from assessing the plain radiograph?. Methodology: This study involved 24 patients with intra-articular fracture of the calcaneum who had both a plain radiograph and a CT scan as a part of their assessment. Three consultants who were blinded to the actual management and names of the subjects were independently asked to grade the radiographs and CT scans, as operative or non-operative, on different occasions. The data was matched to the actual management and was subjected to statistical analysis. Results: The data was non-parametric and related. The SIGN test was used to analyse the agreement between the three observers and if the decisions made in each of the groups were significantly different from the actual management. There was no statistically significant difference, between the management decision from the radiographs or CT and the actual management. The change in management that the CT scan brought about was also assessed for each of the observers using the McNemars test. The CT scan did not make any significant difference to the decision made based on the plain radiographs, on whether to operate or not. A Cochran Q test used to assess the variability of the decisions, showed that there was more inter-observer variability in decision making, using the CT based assessment (Q=9.50, p=0.009) as compared to plain radiographs (Q=3.84, p=0.14). Conclusion: We conclude that, the CT scan should only be requested when a decision is made to operate on the fracture, based on plain radiographs. This may help with pre-operative planning of fracture fixation. It does not have to be obtained as a routine to assess all intra-articular fractures of the calcaneum

A painful “dreaded black line” (DBL) has been associated with progression to complete fractures in atypical femur fractures (AFF). Adjacent sclerosis, an unrecognized radiological finding, has been observed in relation to the DBL. We document its incidence, associated features, demographics and clinical progression. We reviewed plain radiographs of 109 incomplete AFFs between November 2006 and June 2021 for the presence of sclerosis adjacent to a DBL. Radiographs were reviewed for location of lesions, and presence of focal endosteal or periosteal thickening. We collected demographical data, type and duration of bisphosphonate therapy, and progression to fracture or need for prophylactic stabilization, with a 100% follow up of 72 months (8 – 184 months). 109 femurs in 86 patients were reviewed. Seventeen sclerotic DBLs were observed in 14 patients (3 bilateral), involving 15.6% of all femora and 29.8% of femora with DBLs. Location was mainly subtrochanteric (41.2%), proximal diaphyseal (35.3%) and mid-diaphyseal (23.5%), and were associated with endosteal or periosteal thickening. All patients were female, mostly Chinese (92.9%), with a mean age of 69 years. 12 patients (85.7%) had a history of alendronate therapy, and the remaining 2 patients had zoledronate and denosumab therapy respectively. Mean duration of bisphosphonate therapy was 62 months. 4 femora (23.5%) progressed to complete fractures that were surgically managed, whilst 6 femora (35.3%) required prophylactic fixation. Peri-lesional sclerosis in DBL is a new radiological finding in AFFs, predominantly found in the proximal half of the femur, at times bilateral, and are always associated with endosteal or periosteal thickening. As a high proportion of patients required surgical intervention, these lesions could suggest non-union of AFFs, similar to the sclerotic margins commonly seen in fractures with non-union. The recognition of and further research into this new feature could shed more light on the pathophysiological progression of AFFs

There is some evidence to suggest that outcomes of THA in patients with minimal radiographic osteoarthritis may not be associated with predictable outcomes. The aim of this study was to:. Assess the outcome of patients with hip pain who underwent THA with no or minimal radiographic signs of osteoarthritis,. Identify patient comorbidities and multiplanar imaging findings which are predictive of outcome,. Compare the outcome in these patients to the expected outcome of THA in hip OA. A retrospective review of 107 hips (102 patients, 90F:12M, median age 40.6, IQR 35.1–45.8 years, range 18–73) were included for analysis. Plain radiographs were evaluated using the Tonnis grading scale of hip OA. Outcome measures were all-cause revision; iHOT12; EQ-5D; Oxford Hip Score; UCLA Activity Scale; and whether THA had resulted in the patient's hip pain and function being Better/Same/Worse. The median Oxford Hip Score was 33.3 (IQR 13.9, range 13–48), and 36/107 (33.6%) hips achieved an OHS≥42. There was no association between primary hip diagnosis and post-operative PROMs. A total of 91 of the 102 patients (89.2%, 93 hips) reported that their hip pain and function was Better than prior to THA and would have the surgery again, 7 patients (6.8%, 10 hips) felt the Same, and 4 patients (3.9%, 4 hips) felt Worse and would not have the surgery again. Younger patients undergoing total hip arthroplasty with no or minimal radiographic osteoarthritis had lower postoperative Oxford Hip Scores than the general population; though most felt symptomatically better and knowing what they know now, would have surgery again. Those with chronic pain syndrome or hypermobility were likely to benefit less. Those with subchondral cysts or joint space narrowing on CT imaging were more likely to achieve higher functional scores and satisfaction

Applications of weightbearing computed tomography (WBCT) imaging in the foot and ankle have emerged over the past decade. However, the potential diagnostic benefits are scattered across the literature, and a concise overview is currently lacking. Therefore, we aimed to systematically review all reported diagnostic applications per anatomical region in the foot and ankle. A systematic literature search was performed in the electronic databases PubMed, EMBASE, Cochrane Library, and Web of Science. Search terms consisted of “weightbearing/standing CT and ankle, hind-, mid- or forefoot”. English language studies analyzing the diagnostic applications of WBCT were included. Studies were excluded if they simulated weightbearing CT, described normal subjects, included cadaveric samples or samples were case reports. The modified Methodological Index for Non-Randomized Studies (MINORS) was applied for quality assessment. The added value was defined as the review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered in the Prospero database (CRD42019106980). A total of 48 studies (prospective N=8, retrospective N=36, cohort study N=1, diagnostic N=2, prognostic comparative study N=1) were found to be eligible for review. The following diagnostic applications were identified per anatomical area in the foot: ankle (osteoarthritis N=5, ligament injury N=6); hindfoot (deformity N=9); midfoot (Lisfranc injury N=2, flatfoot deformity N=13, osteoarthritis N=1); forefoot (hallux valgus N=12). The identified studies contained diagnostic applications that could not be used on plain radiographs. The mean MINORS equaled 10.1 on a total of 16 (range: 8 to 12). Diagnostic applications of weightbearing CT imaging are most frequently studied in hindfoot deformity, but other area's areas are on the rise. Post-processing of images was identified as the main added value compared to WBRX. However, the findings should be interpreted with caution as the average quality score was moderate. Therefore, future prospective studies are warranted to consolidate the role of WBCT in diagnostic and therapeutic algorithms

Aims. To benchmark the radiation dose to patients during the course of treatment for a spinal deformity. Methods. Our radiation dose database identified 25,745 exposures of 6,017 children (under 18 years of age) and adults treated for a spinal deformity between 1 January 2008 and 31 December 2016. Patients were divided into surgical (974 patients) and non-surgical (5,043 patients) cohorts. We documented the number and doses of ionizing radiation imaging events (radiographs, CT scans, or intraoperative fluoroscopy) for each patient. All the doses for plain radiographs, CT scans, and intraoperative fluoroscopy were combined into a single effective dose by a medical physicist (milliSivert (mSv)). Results. There were more ionizing radiation-based imaging events and higher radiation dose exposures in the surgical group than in the non-surgical group (p < 0.001). The difference in effective dose for children between the surgical and non-surgical groups was statistically significant, the surgical group being significantly higher (p < 0.001). This led to a higher estimated risk of cancer induction for the surgical group (1:222 surgical vs 1:1,418 non-surgical). However, the dose difference for adults was not statistically different between the surgical and non-surgical groups. In all cases the effective dose received by all cohorts was significantly higher than that from exposure to natural background radiation. Conclusion. The treatment of spinal deformity is radiation-heavy. The dose exposure is several times higher when surgical treatment is undertaken. Clinicians should be aware of this and review their practices in order to reduce the radiation dose where possible. Cite this article: Bone Joint J 2021;103-B(4):1–7

Introduction. Tibial Pilon fractures are potentially limb threatening, yet standards of care are lacking from BOFAS and the BOA. The mantra of “span, scan, plan” describes staged management with external fixation to allow soft tissue resuscitation, followed by a planning CT-scan. Our aim was to evaluate how Tibial Pilon fractures are acutely managed. Methods. ENFORCE was a multi-centre retrospective observational study of the acute management of partial and complete articular Tibial Pilon fractures over a three-year period. Mechanism, imaging, fracture classification, time to fracture reduction and cast, and soft tissue damage control details were determined. Results. 656 patients (670 fractures) across 27 centres were reported. AO fracture classifications were: partial articular (n=294) and complete articular (n=376). Initial diagnostic imaging mobilities were: plain radiographs (n=602) and CT-scan (n=54), with all but 38 cases having a planning CT-scan. 526 fractures had a cast applied in the Emergency Department (91 before radiological diagnosis), with the times taken to obtain post cast imaging being: mean 2.7 hours, median 2.3 hours, range 28 mins – 14 hours). 35% (102/294) of partial articular and 57% (216/376) of complete articular (length unstable) fractures had an external fixator applied, all of which underwent a planning CT-scan. Definitive management consisted of: open reduction internal fixation (n=495), fine wire frame (n=86), spanning external fixator (n=25), intramedullary nail (n=25), other (n=18). Conclusion. The management of Tibial Pilon fractures is variable, with prolonged delays in obtaining post cast reduction radiographs, and just over half of length unstable complete articular fractures being managed with the gold standard “span, scan, plan” staged soft tissue resuscitation. A BOFAS endorsed BOAST (British Orthopaedic Association Standard for Trauma) for Tibial Pilon fractures is suggested for standardisation of the acute management of these potentially limb threatening injuries, together with setting them apart from more straightforward ankle fractures

Introduction. We aim to assess whether radiographic characteristics of the greater tuberosity fragment can predict rotator cuff tears inpatients with anterior shoulder dislocations combined with an isolated fracture of the greater tuberosity. Methods. A retrospective single-centre case series of 61 consecutive patients that presented with anterior shoulder dislocations combined with an isolated fracture of the greater tuberosity between January 2018 and July 2022. Inclusion criteria: patients with atraumatic anterior shoulder dislocation associated with an isolated fracture of the greater tuberosity with a minimum follow-up of 3-months. Exclusion criteria: patients with other fractures of the proximal humerus or glenoid. Rotator cuff tears were diagnosed using magnetic resonance or ultrasound imaging. Greater tuberosity fragment size and displacement was calculated on plain radiographs using validated methods. Results. The case series was composed of 22 men and 39 women with a mean age of 65 years (29 - 91 years). The mean follow-up was 15months and median follow up 8.5 months (3 – 60 months). A rotator cuff tear was diagnosed in 14 patients (16%) and involved the supraspinatus (13), infraspinatus (4) and subscapularis (2). Full-thickness tears occurred in 6 patients and partial-thickness tears in 8patients. The mean time from initial injury to rotator cuff tear diagnosis was 5 months (2 – 22 months). The mean greater tuberosity fragment length was 23.4 mm in rotator cuff tear patients versus 32.6 mm in those without a tear (p = 0.006, CI: -15 - -2). The mean greater tuberosity. fragment width was 11.1 mm in rotator cuff tear patients versus 17.8 mm in those without a tear (p = 0.0004, CI: -10 - -2). There was no significant difference in the super inferior and anteroposterior fragment displacement between the two groups. Conclusion. In patients with shoulder dislocations combined with an isolated fracture of the greater tuberosity, rotator cuff tears are associated with a smaller sized greater tuberosity fragment

Aims. The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery. Methods. A total of 454 consecutive patients who underwent cementless TKA between August 2004 and December 2021 were reviewed. The mean follow-up was ten years. Plain radiographs were analyzed for radiolucent lines. Patients who underwent revision TKA were recorded, and the cause for revision was determined. Data from the National Joint Registry for England, Wales, Northern Island, the Isle of Man and the States of Guernsey (NJR) were compared with our series. Results. No patients in our series had evidence of radiolucent lines on their latest radiological assessment. Only eight patients out of 454 required revision arthroplasty, and none of these revisions were indicated for aseptic loosening of the tibial baseplate. When compared to data from the NJR annual report, Kaplan-Meier estimates from our series (2.94 (95% confidence interval (CI) 1.24 to 5.87)) show a significant reduction in cumulative estimates of revision compared to all cemented (4.82 (95% CI 4.69 to 4.96)) or cementless TKA (5.65 (95% CI 5.23 to 6.10)). Our data (2.94 (95% CI 1.24 to 5.87)) also show lower cumulative revision rates compared to the most popular implant (PFC Sigma Cemented Knee implant fixation, 4.03 (95% CI 3.75 to 4.33)). The prosthesis time revision rate (PTIR) estimates for our series (2.07 (95% CI 0.95 to 3.83)) were lower than those of cemented cases (4.53 (95% CI 4.49 to 4.57)) from NJR. Conclusion. The NexGen trabecular (tantalum) cementless implant has lower revision rates in our series compared to all cemented implants and other types of cementless implants, and its use in younger patients should be encouraged. Cite this article: Bone Jt Open 2024;5(4):277–285

Aims. The aim of this study was to compare the clinical and radiological outcomes of patients with early-onset scoliosis (EOS), who had undergone spinal fusion after distraction-based spinal growth modulation using either traditional growing rods (TGRs) or magnetically controlled growing rods (MCGRs). Methods. We undertook a retrospective review of skeletally mature patients who had undergone fusion for an EOS, which had been previously treated using either TGRs or MCGRs. Measured outcomes included sequential coronal T1 to S1 height and major curve (Cobb) angle on plain radiographs and any complications requiring unplanned surgery before final fusion. Results. We reviewed 43 patients (63% female) with a mean age of 6.4 years (SD 2.6) at the index procedure, and 12.2 years (SD 2.2) at final fusion. Their mean follow-up was 8.1 years (SD 3.4). A total of 16 patients were treated with MCGRs and 27 with TGRs. The mean number of distractions was 7.5 in the MCGR group and ten in the TGR group (p = 0.471). The mean interval between distractions was 3.4 months in the MCGR group and 8.6 months in the TGR group (p < 0.001). The mean Cobb angle had improved by 25.1° in the MCGR group and 23.2° in TGR group (p = 0.664) at final follow-up. The mean coronal T1 to S1 height had increased by 16% in the MCGR group and 32.9% in TGR group (p = 0.001), although the mean T1 to S1 height achieved at final follow-up was similar in both. Unplanned operations were needed in 43.8% of the MCGR group and 51.2% of TGR group (p = 0.422). Conclusion. In this retrospective, single-centre review, there were no significant differences in major curve correction or gain in spinal height at fusion. Although the number of planned procedures were fewer in patients with MCGRs, the rates of implant-related complications needing unplanned revision surgery were similar in the two groups. Cite this article: Bone Joint J 2022;104-B(2):257–264

An MR scan was performed on all patients who presented to our hospital with a clinical diagnosis of a fracture of the proximal femur, but who had no abnormality on plain radiographs. This was a prospective study of 102 consecutive patients over a ten-year period. There were 98 patients who fulfilled our inclusion criteria, of whom 75 were scanned within 48 hours of admission, with an overall mean time between admission and scanning of 2.4 days (0 to 10). A total of 81 patients (83%) had abnormalities detected on MRI; 23 (23%) required operative management. The use of MRI led to the early diagnosis and treatment of occult hip pathology. We recommend that incomplete intertrochanteric fractures are managed non-operatively with protected weight-bearing. The study illustrates the high incidence of fractures which are not apparent on plain radiographs, and shows that MRI is useful when diagnosing other pathology such as malignancy, which may not be apparent on plain films

Traditionally, sports Injuries have been sub-optimally managed through Emergency Departments (ED) in the public health system due to a lack of adequate referral processes. Fractures are ruled out through plain radiographs followed by a reactive process involving patient initiated further follow up and investigation. Consequently, significant soft tissue and chondral injuries can go undiagnosed during periods in which early intervention can significantly affect natural progression. The purpose of this quality improvement project was to assess the efficacy of an innovative Sports Injury Pathway introduced to detect and treat significant soft tissue injuries. A Sports Injury Pathway was introduced at Fiona Stanley Hospital (WA, Australia) in April 2019 as a collaboration between the ED, Physiotherapy and Orthopaedic Departments. ED practitioners were advised to have a low threshold for referral, especially in the presence of a history of a twisting knee injury, shoulder dislocation or any suggestion of a hip tendon injury. All referrals were triaged by the Perth Sports Surgery Fellow with early follow-up in our Sports Trauma Clinics with additional investigations if required. A detailed database of all referrals was maintained, and relevant data was extracted for analysis over the first 3 years of this pathway. 570 patients were included in the final analysis. 54% of injuries occurred while playing sport, with AFL injuries constituting the most common contact-sports injury (13%). Advanced Scope Physiotherapists were the largest source of referrals (60%). A total of 460 MRI scans were eventually ordered comprising 81% of total referrals. Regarding Knee MRIs, 86% identified a significant structural injury with ACL injuries being the most common (33%) followed by isolated meniscal tears (16%) and multi-ligament knee injuries (11%). 95% of Shoulder MRI scans showed significant pathology. 39% of patients required surgical management, and of these 50% were performed within 3 months from injury. The Fiona Stanley Hospital Sports Injury Pathway has demonstrated its clear value in successfully diagnosing and treating an important cohort of patients who present to our Emergency Department. This low threshold/streamlined referral pathway has found that the vast majority of these patients suffer significant structural injuries that may have been otherwise missed, while providing referring practitioners and patients access to prompt imaging and high-quality Orthopaedic sports trauma services. We recommend the implementation of a similar Sports Injury Pathway at all secondary and tertiary Orthopaedic Centres

Mirels’ score predicts the likelihood of sustaining pathological fractures using pain, lesion site, size and morphology. The aim is to investigate its reproducibility, reliability and accuracy in upper limb bony metastases and validate its use in pathological fracture prediction. A retrospective cohort study of patients with upper limb metastases, referred to an Orthopaedic Trauma Centre (2013–18). Mirels’ was calculated in 32 patients; plain radiographs at presentation scored by 6 raters. Radiological aspects were scored twice by each rater, 2-weeks apart. Inter- and intra-observer reliability were calculated (Fleiss’ kappa test). Bland-Altman plots compared variances of individual score components &total Mirels’ score. Mirels’ score of ≥9 did not accurately predict lesions that would fracture (11% 5/46 vs 65.2% Mirels’ score ≤8, p<0.0001). Sensitivity was 14.3% &specificity was 72.7%. When Mirels’ cut-off was lowered to ≥7, patients were more likely to fracture (48% 22/46 versus 28% 13/46, p=0.045). Sensitivity rose to 62.9%, specificity fell to 54.6%. Kappa values for interobserver variability were 0.358 (fair, 0.288–0.429) for lesion size, 0.107 (poor, 0.02–0.193) for radiological appearance and 0.274 (fair, 0.229–0.318) for total Mirels’ score. Values for intraobserver variability were 0.716 (good, 95% CI 0.432–0.999) for lesion size, 0.427 (moderate, 95% CI 0.195–0.768) for radiological appearance and 0.580 (moderate, 0.395–0.765) for total Mirels’ score. We showed moderate to substantial agreement between &within raters using Mirels’ score on upper limb radiographs. Mirels’ has poor sensitivity &specificity predicting upper limb fractures - we recommend the cut-off score for prophylactic surgery should be lower than for lower limb lesions

Aims. The purpose of this study was to compare the clinical, radiological, and patient-reported outcome measures (PROMs) in the first 100 consecutive patients undergoing total hip arthroplasty (THA) via a direct superior approach (DSA) with a matched group of patients undergoing THA by the same surgeon, using a posterolateral approach (PLA). Methods. This was a retrospective single surgeon study comparing the first 100 consecutive DSA THA patients with a matched group of patients using a standard PLA. Case notes were examined for patient demographics, length of hospital stay, operating time, intra- and postoperative complications, pain score, satisfaction score, and Oxford Hip Score (OHS). Leg length discrepancy and component positioning were measured from postoperative plain radiographs. Results. The DSA patients had a shorter length of hospital stay (mean 2.09 days (SD 1.20) DSA vs 2.74 days (SD 1.17) PLA; p < 0.001) and shorter time to discharge from the inpatient physiotherapy teams (mean 1.44 days (SD 1.17) DSA vs 1.93 days (SD 0.96) PLA; p < 0.001). There were no differences in operating time (p = 0.505), pain levels up to postoperative day 1 (p = 0.106 to p =0.242), OHS (p = 0.594 to p = 0.815), satisfaction levels (p = 0.066 to p = 0.299), stem alignment (p = 0.240), acetabular component inclination (p < 0.001) and anteversion (p < 0.001), or leg length discrepancy (p = 0.134). Conclusion. While the DSA appears safe and was not associated with a significant difference in PROMs, radiological findings, or intraoperative or postoperative complications, a randomized controlled trial with functional outcomes in the postoperative phase is needed to evaluate this surgical approach formally. Cite this article: Bone Joint J 2021;103-B(3):500–506

Background. Recent studies have suggested that full-limb radiographs are more accurate and sensitive than short film radiographs for pre-operative measurement of the anatomical angles required to achieve optimal knee alignment in Total Knee Arthroplasty (TKA). However, there are drawbacks associated with their use including excess radiation to the pelvic organs, the need for specialised radiography equipment and increased cost. Given these drawbacks, we compared the use of MRI scans, a commonly performed pre-operative investigation, with short film knee radiographs for measurement of knee alignment. Objective. To investigate whether knee alignment measurements made on MRI scans correlate with those measured on short film knee radiographs in patients with osteoarthritic knees. Methods. We retrospectively reviewed short film knee radiographs and MRI scans of 50 patients with knee osteoarthritis. The plain radiographs had to be performed whilst weight bearing. The MRI scans were performed supine and non-weight bearing. The exclusion criteria included previous trauma to the knee, previous TKA and previous fracture of the lower limb. 4 angle measurements defined by The American Knee Society: alpha, beta, sigma and gamma were measured using each of the 2 modalities. Kolmogorov-Smirnov and two- tailed paired t-tests were used for statistical analysis of the results. Pearson correlation coefficient was used for the measure of dependence. Results. The alpha, beta, sigma and gamma angles obtained using the MR images were different to those obtained using short film weight bearing knee radiographs by −3°± 1° (p < 0.001), 1° ± 3° (p=0.002), 1° ± 3° (p=0.047) and 1° ± 4° (p=0.113) respectively. There was a weak correlation between the MRI based method and the radiographic method in measuring all 4 angles. Conclusions. Our results have shown that the angular measurements performed on MR images should be interpreted with caution as they may vary depending on the MRI slice selected for evaluation. The differences observed and the weak correlation between the 2 modalities may be due to the different scopes used for determining the femoral or tibial axes. The measurements obtained using the plain radiographs were interpreted using a single 2D projection of a 3D structure. However, the measurements of the MR images were evaluated using a 2D image of a slice through a 3D structure. In conclusion, the use of MRI scans for pre-operative planning in TKA may not be advisable at this stage as the angular measurements obtained using the MR images were poorly correlated to those obtained using plain radiographs

Interobserver reliability of the AO system of classification of fractures of the distal radius was assessed using plain radiographs and CT. Five observers classified 30 Colles’-type fractures using only plain radiographs; two months later they were reclassified using CT in addition. Interobserver reliability was poor in both series when detailed classification was used. By reducing the categories to five, interobserver reliability was slightly improved, but was still poor. When only two AO types were used, the reliability was moderate using plain radiographs and good to excellent with the addition of CT. The use of CT as well as plain radiographs brings interobserver reliability to a good level in assessment of the presence or absence of articular involvement, but is otherwise of minor value in improving the interobserver reliability of the AO system of classification of fractures of the distal radius

Introduction: While plain radiographs are the clinical standard for routine follow-up after total knee arthroplasty (TKA), periprosthetic osteolysis can be difficult to identify on radiographs because it is often obscured by the metallic prosthesis. This study sought to evaluate the pattern and size of periprosthtic osteolytic lesions after TKA in patients with rheumatoid arthritis using multi-detector computed tomography (MDCT). Methods: We evaluated 25 primary cemented alumina-ceramic TKAs (LFA-I, Kyocera) using minimum 10-year CT scans. All TKAs had an alumina-ceramic femoral component, a titanium tibial baseplate with a poly-ethylene insert, and a polyethylene patella component, which had been fixed with cement. The average age at the time of surgery was 54.1 years. The average time interval between surgery and the computed tomography scan was 12.6 years. None of the patients in this study documented periprosthetic infection or had undergone bone grafting. Results: The MDCT detected 31 lesions in 12 knees: 23 femoral and 8 tibial lesions. All lesions occurred around the prosthetic rim, and the mean size of osteolysis per knee was 2.1 +/−1.5 cc (range, 0.4–4.7 cc). Only seven lesions in 6 knees were diagnosed as osteolysis on plain radiographs: 2 lesions at anterior femoral condyle and 5 lesions at tibial condyles. None of the lesions around the posterior condylar flanges detected on CT was identified on plain radiographs. None of the implants showed radiographic loosening or required reoperation. Discussion: As the alumina-ceramic TKA allowed the CT scans to obtain clear images with little metal artifact, we could easily detect lesions and joint space communication. This study demonstrated that plain radiographs underestimated osteolysis, and that lesions around posterior femoral condyles were the most difficult to identify on radiographs. Although most of the lesions were small and may be of little clinical importance, this study confirmed that MDCT can accurately detect osteolysis and measure lesion volumes in alumina-ceramic TKA

Introduction:. Most of the published papers on AI based diagnosis have focused on the algorithm's diagnostic performance in a ‘binary’ setting (i.e. disease vs no disease). However, no study evaluated the actual value for the clinicians of an AI based approach in diagnostic. Detection of Traumatic thoracolumbar (TL) fractures is challenging on planar radiographs, resulting in significant rates of missed diagnoses (30-60%), thus constituting a field in which a performance improvement is needed. Aim of this study is therefore to evaluate the value provided by AI generated saliency maps (SM), i.e. the maps that highlight the AI identified region of interests. Methods:. An AI model aimed at identifying TL fractures on plain radiographs was trained and tested on 567 single vertebrae images. Three expert spine surgeons established the Ground Truth (GT) using CT and MRI to confirm the presence of the fracture. From the test set, 12 cases (6 with a GT of fracture and 6 with a GT of no fracture, associated with varying levels of algorithm confidence) were selected and the corresponding SMs were generated and shown to 7 independent evaluators with different grade of experience; the evaluators were requested to: (1) identify the presence or absence of a fracture before and after the saliency map was shown; (2) grade, with a score from 1 (low) to 6 (high) the pertinency (correlation between the map and the human diagnosis), and the utility (the perceived utility in confirming or not the initial diagnosis) of the SM. Furthermore, the usefulness of the SM was evaluated through the rate of correct change in diagnosis after the maps had been shown. Finally, the obtained scores were correlated with the algorithm confidence for the specific case. Results:. Of the selected maps, 8 had an agreement between the AI diagnosis and the GT, while in 4 the diagnosis was discordant (67% accuracy). The pertinency of the map was found higher when the AI diagnosis was the same as the GT and the human diagnosis (respectively p-value = .021 and <.000). A positive and significant correlation between the AI confidence score and the perceived utility (Spearman: 27%, p-value=.0-27) was found. Furthermore, evaluator with experience < 5 year found the maps more useful than the experts (z-score=2.004; p-value=.0455). Among the 84 evaluation we found 12 diagnostic errors in respect to the GT, 6 (50%) of which were reverted after the saliency map evaluation (z statistic = 1.25 and p-value = .21). Discussion:. The perceived utility of AI generated SM correlate with the model confidence in the diagnosis. This highlights the fact that to be considered helpful, the AI must provide not only the diagnosis but also the case specific confidence. Furthermore, the perceived utility was higher among less experienced users, but overall, the SM were useful in improving the human diagnostic accuracy. Therefore, in this setting, the AI enhanced approach provides value in improving the human performance

Between 2002 and 2008, 130 consecutive ankles were replaced with an hydroxyapatite (HA) and titanium-HA-coated Ankle Evolutive System total ankle prosthesis. Plain radiographs were analysed by two independent observers. Osteolytic lesions were classified by their size and location, with cavities > 10 mm in diameter considered to be ‘marked’. CT scanning was undertaken in all patients with marked osteolysis seen on the plain radiographs. Osteolytic lesions were seen on the plain films in 48 (37%) and marked lesions in 27 (21%) ankles. The risk for osteolysis was found to be 3.1 (95% confidence interval 1.6 to 5.9) times higher with implants with Ti-HA porous coating. Care should be taken with ankle arthroplasty until more is known about the reasons for these severe osteolyses

Introduction. The Vancouver Classification System presents a systematic approach to classification of periprosthetic fractures of the proximal femur (PFPFs) that has been validated in previous studies. However, with the introduction of tapered fluted stems and cable plates since the introduction of the Vancouver System, the connection between fracture class and the preferred method of treatment is often unclear. The present study was undertaken to identify fracture patterns surrounding contemporary femoral stems and the relationship between the current method of treatment and the Vancouver Class of the periprosthetic fracture. Methods. Three experienced joint surgeons collected plain radiographs (AP and lateral) and CT/MR scans (n=40) from 72 cases of Vancouver A or B periprosthetic fractures performed over the period 2016–2018. We identified the mode of primary stem fixation and the Vancouver grade of the fracture (A, B1, B2 or B3). Two independent investigators examined all imaging studies and the intraoperative records and recorded: (i) and the location and distribution of the fracture surfaces, and (ii) the presence of incomplete cortical fractures that had initiated within the femoral cortex without completing propagation and (iii) the method of operative treatment. These data were analyzed to examine the incidence of fractures within more than one femoral zone and differences in the fracture patterns corresponding to each Vancouver class. Results. One fifth (21%) of fractures were Type A with the remainder consisting predominantly of Type B2 (39%), with approximately equal proportions of Type B1 (22%) and B3 (18%) fractures. In almost half of Type B2 fractures (a loose femoral stem and a fracture adjacent to the prosthesis), fractures were also present within the metaphysis (ie. Type A+B). In the presence of a cementless femoral stem, fractures often occurred adjacent to the uncoated surface of the stem distal to the proximal ingrowth surface. Type B2 and B3 femurs had similar fracture patterns and degrees of comminution, though their method of treatment differed significantly. Incomplete fractures were identified in every Vancouver class (entire sample: 22%), especially in association with loose stems in poor quality bone (Type B3; 38% of cases). Conclusions. Approximately two-thirds of periprosthetic femoral fractures involve a loose femoral component (ie Types B2 and B3), though bone quality impacts operative treatment. In cementless stems, Vancouver Type B fractures often occur in the unbonded diaphysis between the distal edge of the ingrowth surface and immediately below the stem tip. Incomplete fractures are present in a surprising proportion of cases, suggesting that careful examination of imaging studies is needed to prevent fracture propagation due to inadequate fixation. CT scans are a useful adjunct to supplement plain radiographs. For any tables or figures, please contact the authors directly

Background/Purpose. Cross-linked polyethylene (XLPE) has shown reduced wear rates as compared to conventional polyethylene, but the long-term effect of this on the incidence of osteolysis remains unclear. In addition, the measurement of osteolysis on plain radiographs can underestimate the incidence and extent of osteolysis. Therefore, we evaluated the wear rate, incidence and volume of osteolysis at a minimum follow-up of ten years using three-dimensional computed tomography (3-D CT), a more accurate and sensitive method for detecting and measuring the size of osteolysis than plain radiographs. Materials and Methods. Between 2000 and 2004, 233 primary THAs were performed using 28-mm cobalt-chrome femoral head on first-generation XLPE (Longevity. ®. , Zimmer, Warsaw, IN) with cups of identical design. Fifty-five patients (57 hips) deceased, eight patients (8 hips) were lost and four patients (4 hips) were revised due to recurrent dislocation (2 hips) or infection (2 hips). Among the remaining 164 hips, 95 hips underwent 3-D CT scanning (Aquilion® 64, Lightspeed Ultra® 16 or Optima® 660) at minimum 10 years (range, 10.0 to 15.2) and were included in this study. Mean age at the time of THA was 56.2 years and average body mass index was 23.5 kg/m. 2. Average cup size was 55.4 mm whereas mean inclination and anteversion angle of cups on CT scan were 40.1 and 17.4 degrees, respectively. Average follow-up period was 12.8 years. 2D wear rate was measured using PolyWare® 3D Rev 7 software (Draftware Inc, Vevay, IN). Osteolysis was strictly defined as a localized area of trabecular loss with a sclerotic margin. Osteoarthritic cyst and age-related osteoporosis were excluded using perioperative CT scan and magnetic resonance imaging or serial plain radiographs. The incidence, location, and volume of osteolysis were measured. Results. Mean bedding-in wear rate (<1 yr) was 0.085 mm and average annual wear rate was 0.023 ± 0.012 mm/yr. Seven hips (7.4%) demonstrated osteolysis on 3-D CT scan: Acetabular osteolysis was measured with an average volume of 3.2 cm. 3. in zone 1 or 2 in three hips whereas femoral osteolysis was demonstrated with a mean volume of 0.7 cm. 3. in zone 1 or 7 in 5 hips. One hip showed both acetabular and femoral osteolysis. Conclusion. The results of THA using first-generation XLPE were encouraging with low wear rate as well as low incidence of osteolysis at a minimum follow-up of ten years. Longer follow-up is necessary to determine if this XLPE will continue to demonstrate the improved osteolysis characteristics. Acknowledgement: This work was supported by Institute for Information & communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (#B0101-14-1081)

Aims. Patient-specific instrumentation has been shown to increase a surgeon’s precision and accuracy in placing the glenoid component in shoulder arthroplasty. There is, however, little available information about the use of patient-specific planning (PSP) tools for this operation. It is not known how these tools alter the decision-making patterns of shoulder surgeons. The aim of this study was to investigate whether PSP, when compared with the use of plain radiographs or select static CT images, influences the understanding of glenoid pathology and surgical planning. Methods. A case-based survey presented surgeons with a patient’s history, physical examination, and, sequentially, radiographs, select static CT images, and PSP with a 3D imaging program. For each imaging modality, the surgeons were asked to identify the Walch classification of the glenoid and to propose the surgical treatment. The participating surgeons were grouped according to the annual volume of shoulder arthroplasties that they undertook, and responses were compared with the recommendations of two experts. Results. A total of 59 surgeons completed the survey. For all surgeons, the use of the PSP significantly increased agreement with the experts in glenoid classification (x. 2. = 8.54; p = 0.014) and surgical planning (x. 2. = 37.91; p < 0.001). The additional information provided by the PSP also showed a significantly higher impact on surgical decision-making for surgeons who undertake fewer than ten shoulder arthroplasties annually (p = 0.017). Conclusions. The information provided by PSP has the greatest impact on the surgical decision-making of low volume surgeons (those who perform fewer than ten shoulder arthroplasties annually), and PSP brings all surgeons in to closer agreement with the recommendations of experts for glenoid classification and surgical planning. Cite this article: Bone Joint J 2020;102-B(3):365–370

The reliability and accuracy of plain radiographs, MRI and CT Arthrography to detect the presence of loose bodies was evaluated in twenty-six patients with mechanical elbow symptoms. The location of loose bodies found by the imaging studies was compared to arthroscopic findings. Overall sensitivity for the detection of loose bodies was 88 – 100% and specificity was 20 – 70%. Plain radiographs had a similar sensitivity and specificity of 84% and 71% respectively. MRI and CT Arthrography were similar to plain radiography, suggesting that routine use of these modalities is not indicated. The purpose of this study was to determine the clinical utility of MRI and CT Arthrography (CTA) to reliably and accurately predict the presence of loose bodies in the elbow. Twenty-six patients with mechanical elbow symptoms underwent plain radiography, MRI and CTA, followed by standard elbow arthroscopy. Three musculoskeletal radiologists reviewed the ‘blinded’ plain radiographs with both the MRI and CTA at separate sittings. The location and number of loose bodies on the MRI and CTA were recorded. The preoperative plain radiographs, MRI and CTA were compared to the arthroscopic findings. Agreement between radiologists was higher for the number of loose bodies identified in the posterior compartment (ICC=0.72 for both MRI and CTA) than in the anterior compartment (ICC=0.41 and 0.52 for MRI and CTA respectively). The correlation between the number of lose bodies observed on MRI and CTA compared to those found arthroscopically was also higher in the posterior compartment (r=0.54–0.85) than in the anterior compartment (r=0.01–0.45). Both MRI and CTA had excellent sensitivity (92–100%) but moderate to low specificity (15–77%) in identifying posteriorly located loose bodies. Neither MRI nor CTA were consistently sensitive (46–91%) or specific (13–73%) in predicting anterior loose bodies. Overall sensitivity for the detection of loose bodies in either compartment was 88–100% and specificity was 20–70%. The preoperative radiographs had a similar sensitivity and specificity of 84% and 71% respectively. MRI and CTA were similar to plain radiography in the prediction of elbow loose bodies

Background: CT scanning is an essential part of the preoperative planning process prior to surgical fixation of acetabular fractures. Considerable disparity exists between the clinical and radiological outcome following open reduction and internal fixation of these fractures. It is suggested that this disparity is due to poor assessment of the quality of reduction using plain radiographs alone. Aim: To investigate the role of post-operative CT scanning following ORIF of acetabular fractures. Methods. Prospective study commenced in January 2000 of all patients in our institution undergoing internal fixation of acetabular fractures. Post operative axial CT scans were compared with plain radiographs (AP pelvis and 45 degree oblique Judet views) with regard to the sensitivity to detect articular fracture reduction in terms of gap displacement and step deformity or offset. A simplified binary measurement of radiological outcome was used stratifying radiological result into anatomical and non anatomical. Three observers independently reviewed the plain radiographs and CT scans at two separate time points and categorised the radiographic outcome as described. The interobserver reproducibility and intraobserver reliability of these measurements was expressed as a kappa statistic. In addition in those patients greater than 18 months following surgery we attempted to correlate the radiographic with the clinical outcome using the Harris hip score and the SF-36 score. Results: 20 patients were recruited. Plain films were equieffective in detecting post-operative articular fragment displacement (p=0.24). The interobserver and intraobserver agreement between the radiological outcome measurements were good with respective kappa values of 0.61 and 0.65. There was a weak association between clinical and radiographic outcome as ascribed by post operative CT scans. Conclusion: While there may be an argument for the use of post operative CT scanning of acetabular fractures in selective cases, we did not find any significant benefit of CT scans over plain radiographs in the assessment of reduction or radiological outcome following these injuries. Hence we do not routinely advocate their use in the post operative setting

Background: CT scanning is an essential part of the preoperative planning process prior to surgical fixation of acetabular fractures. Considerable disparity exists between the clinical and radiological outcome following open reduction and internal fixation of these fractures. It is suggested that this disparity is due to poor assessment of the quality of reduction using plain radiographs alone. Aim: To investigate the role of post-operative CT scanning following ORIF of acetabular fractures. Methods: Prospective study commenced in January 2000 of all patients in our institution undergoing internal fixation of acetabular fractures. Post operative axial CT scans were compared with plain radiographs (AP pelvis and 45 degree oblique Judet views) with regard to the sensitivity to detect articular fracture reduction in terms of gap displacement and step deformity or offset. A simplified binary measurement of radiological outcome was used stratifying radiological result into anatomical and non-anatomical. Three observers independently reviewed the plain radiographs and CT scans at two separate time points and categorized the radiographic outcome as described. The interobserver reproducibility and intraobserver reliability of these measurements was expressed as a kappa statistic. In addition in those patients greater than 18 months following surgery we attempted to correlate the radiographic with the clinical outcome using the Harris hip score and the SF-36 score. Results: 20 patients were recruited. Plain films were equieffective in detecting post-operative articular fragment displacement (p=0.24). The interobserver and intraobserver agreement between the radiological outcome measurements were good with respective kappa values of 0.61 and 0.65. There was a weak association between clinical and radiographic outcome as ascribed by post operative CT scans. Conclusion: While there may be an argument for the use of post operative CT scanning acetabular fractures in selective cases, we did not find any significant benefit of CT scans over plain radiographs in the assessment of reduction or radiological outcome following these injuries. Hence we do not routinely advocate their use in the post operative setting

Introduction: Isolated greater trochanter fractures gained clinical importance because of the possibility of their inter-trochanteric extension. Aim: To assess whether the direction and the extent of the fracture measured on plain radiographs could be used to predict the inter-trochanteric extension. Materials and Methods: We reviewed plain radiographs and MRI scans of 24 patients who sustained isolated greater trochanter fractures between year 2003 and 2006. We considered two parameters. extent of fracture in percentage along the intertrochanteric line. angle of the fracture line. Both these parameters were measured on a plain anteroposterior radiograph. To measure the length of fracture we have drawn a straight line along the medial border of femoral shaft extending proximally in to the pelvis. Then we measured the distance between the most superior point of the fracture line on the lateral cortex and the midpoint of lesser trochanter on the first line. Then we measured the length of the fracture starting from the most superior point on the lateral cortex. We estimated the percentage of this fracture length in relation to line. To estimate the angle, again we have drawn a straight line along the medial border of femoral shaft extending proximally in to the pelvis. We have drawn another line in the direction of fracture staring from most superior point of fracture on the lateral cortex joining the first line. We measured the angle between these two lines (Fig 2). We used our Hospital PACS system to measure the angles and the length of the fracture. Results: Out of 24 isolated greater trochanteric fractures as diagnosed by plain radiographs, MRI scans revealed intertrochanteric extension in nine (37.5%). On the plain anteroposterior radiograph, the mean angle of the fracture in those with MRI proven intertrochanteric extension was 34º (range 20º–45º). In those with no intertrochanteric extension on MRI scan, the mean angle was 55º (Range 25º–125º). The mean percentage of length of fracture across the intertrochanteric line was 62% (47%–73%) and 40% (27%–62%) respectively. All the fractures with MRI proven intertrochanteric extension had a fracture angle of < 45º and the percentage of fracture length of > 40%. All the 15 fractures with fracture angle more than 45º did not show intertrochanteric extension on MRI scan. Conclusions: We conclude that those isolated greater trochanteric fractures, with fracture angle of more than 45 º are unlikely to have an intertrochanteric extension. These patients could be mobilised without further MRI scans. Those fractures which fulfil the plain radiographic criteria of extension of more than 40% and fracture angle between 20º–40º are likely to show inter trochanteric extension. These patients need further clinical assessment and MRI scans to confirm the intertrochanteric extension

Introduction: The radiographic criteria for successful lumbar arthrodesis remains controversial. Plain radiographs including flexion-extension views are commonly used to assess fusion, but there is disagreement on the degree of apparent motion that is significant. Helical CT assessment of bridging bone between vertebrae is considered to be the most accurate method currently available. This study compared the use of plain radiographs including flexion-extension views with helical CT scans in the assessment of lumbar interbody fusion. Methods: Plain radiographs (including flexion-extension views) and helical CT scans were performed on 32 patients (47 levels) five years after ALIF using carbon fibre cages and autologous bone. A radiologist assessed fusion utilising the Hutter method to detect movement, whilst a spinal surgeon measured movement in degrees using the Simmons method. Helical CT scans (with sagittal and coronal reformatting) were assessed for the presence of bridging trabecular bone. Results: The radiographic fusion rate was 85% based on the presence of bridging bone, and also 85% with the Hutter method. The fusion rate was 74% when movement of at least two degrees was considered significant, but was 98% with the five degrees cut off adopted by the FDA. Fusion as determined by the presence of bridging trabeculae on helical CT Scans occurred in 67%. Concordance rates were as follows: between plain films and helical CT, 69.5%; between Hutter method and plain films, 76%; between Simmon’s method (two degrees) and helical CT, 67%; and between Simmon’s method with the FDA cut-off of five degrees and CT, 65%. Discussion: The assessment of fusion with radiographs appears to be unreliable. The use of plain films and flexion-extension radiographs clearly overestimated the actual fusion rates. Furthermore, there was low concordance between these methods and the more reliable helical CT. This disparity between fusion rates from radiographs and with helical CT supports the view that plain radiographs, including flexion-extension films are of limited value in the assessment of spinal arthrodesis

Aims. To compare the in vivo long-term fixation achieved by two acetabular components with different porous ingrowth surfaces using radiostereometric analysis (RSA). Methods. This was a minimum ten-year follow-up of a prospective randomized trial of 62 hips with two different porous ingrowth acetabular components. RSA exams had previously been acquired through two years of follow-up. Patients returned for RSA examination at a minimum of ten years. In addition, radiological appearance of these acetabular components was analyzed, and patient-reported outcome measures (PROMs) obtained. Results. In all, 15 hips were available at ten years. There was no statistically significant difference in PROMS between the two groups; PROMs were improved at ten years compared to preoperative scores. Conventional radiological assessment revealed well-fixed components. There was minimal movement for both porous surfaces in translation (X, Y, Z, 3D translation in mm (median and interquartile range (IQR)), StikTite (Smith and Nephew, Memphis, Tennessee, USA): 0.03 (1.08), 0.12 (0.7), 0.003 (2.3), 0.37 (0.30), and Roughcoat (Smith and Nephew): -0.6 (0.59),–0.1 (0.49), 0.1 (1.12), 0.48 (0.38)), and rotation (X, Y, Z rotation in degrees (median and IQR), (Stiktite: -0.4 (3), 0.28 (2), -0.2 (1), and Roughcoat: - 0.4 (1),–0.1 (1), 0.2 (2)). There was no statistically significant difference between the two cohorts (p-value for X, Y, Z, 3D translation - 0.54, 0.46, 0.87, 0.55 and for X, Y, Z rotation - 0.41, 0.23, 0.23 respectively) at ten years. There was significant correlation between two years and ten years 3D translation for all components (r = 0.81(p =< 0.001)). Conclusion. Both porous ingrowth surfaces demonstrated excellent fixation on plain radiographs and with RSA at ten years. Short-term RSA data are good predictors for long-term migration data

Fractures of the distal humeral articular surface which do not involve the medial and lateral columns are often more extensive than is apparent from plain radiographs. This retrospective study describes the epidemiology of this injury using modern classification systems and compares pre-operative radiography with operative findings. The study group included 79 patients with a mean age of 47 years (13 to 91). The annual incidence was 1.5 per 100 000 population, and was highest in women over the age of 60. The majority of the fractures (59; 75%) were sustained in falls from standing height. Young males tended to sustain more high-energy injuries with more complex fracture patterns. In 24% of cases (19) there was a concomitant radial head fracture. Classification from plain radiographs often underestimates the true extent of the injury and computed tomography may be of benefit in pre-operative planning, especially in those over 60 years of age

Aim. The aim of this study was to determine whether the absence of periosteal reaction on plain radiographs was predictive of exchange nail failure in lower limb diaphyseal fracture non-unions. Methods. A consecutive cohort of 20 femora and 35 tibiae undergoing exchange nailing for diaphyseal aseptic (n=39) and septic (n=16) fracture non-union at a single centre from 2003 to 2010. Multiple causes of non-union were found in 29 patients (53%) with infection present in 16 cases (29.1%). Of this cohort 49 fracture non-unions had complete radiographic records (19 femora and 30 tibiae) allowing evaluation of the periosteal callus. The primary outcome was the number of number of revision procedures required to achieve union. Failure was defined was as the requirement of >two revision procedures to achieve union. Results. The absence of periosteal callus from the fracture site on all four cortices conferred a relative risk ratio (RRR) 5.00 (p=0.006) of exchange nail failure in septic fracture non-unions. Receiver operator characteristic curve analysis of number of cortices with periosteal reaction for predicting exchange nail (>two exchange nail procedures) failure in both septic and aseptic cases found an area under the curve of 0.79 (95% confidence interval 0.675–0.904, p<0.0001). The complete absence of callus within 5 mm of the fracture site had a 75% chance of requiring 3 or more exchange nails to obtain union. Conversely the presence periosteal callus on at least one cortex within 5mm of the fracture site had a 100% chance the fracture would unite following 1 or 2 exchange nail procedures. Conclusion. Careful radiographic analysis of lower limb diaphyseal non-union should be undertaken before exchange nailing. The absence of periosteal reaction on plain radiographs in septic fracture non-union is predictive of exchange nail failure

Aims. Several radiological methods of measuring anteversion of the acetabular component after total hip arthroplasty (THA) have been described. These are limited by low reproducibility, are less accurate than CT 3D reconstruction, and are cumbersome to use. These methods also partly rely on the identification of obscured radiological borders of the component. We propose two novel methods, the Area and Orthogonal methods, which have been designed to maximize use of readily identifiable points while maintaining the same trigonometric principles. Patients and Methods. A retrospective study of plain radiographs was conducted on 160 hips of 141 patients who had undergone primary THA. We compared the reliability and accuracy of the Area and Orthogonal methods with two of the current leading methods: those of Widmer and Lewinnek, respectively. Results. The 160 anteroposterior pelvis films revealed that the proposed Area method was statistically different from those described by Widmer and Lewinnek (p < 0.001 and p = 0.004, respectively). They gave the highest inter- and intraobserver reliability (0.992 and 0.998, respectively), and took less time (27.50 seconds (. sd. 3.19); p < 0.001) to complete. In addition, 21 available CT 3D reconstructions revealed the Area method achieved the highest Pearson’s correlation coefficient (r = 0.956; p < 0.001) and least statistical difference (p = 0.704) from CT with a mean within 1° of CT-3D reconstruction between ranges of 1° to 30° of measured radiological anteversion. Conclusion. Our results support the proposed Area method to be the most reliable, accurate, and speedy. They did not support any statistical superiority of the proposed Orthogonal method to that of the Widmer or Lewinnek method. Cite this article: Bone Joint J 2019;101-B:1042–1049

Introduction: The radiographic evaluation of the antero-lateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. The alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion. The aim of our study was to analyse the reliability of The frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement. Patients and Methods: Thirty two patients who presented with femoroacetabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans. Results: A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems. Conclusions: Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate measurement of the alpha angle

The radiographic analysis of over 5000 metal on metal (MoM) hips using Ein Bild Roentgen Analyse (EBRA) software have been recently published in an attempt to determine the influence of cup orientation on bearing function. The validation of this software relies one study, conducted in a phantom pelvis without a femoral head in situ. Three dimensional computed tomographic (3D-CT) has been shown to be more accurate for hip and knee arthroplasty than plain radiographs for measurements of component orientation and position. The accuracy of EBRA when compared to 3D-CT for MoM hips specifically is unclear. We measured the cup orientation of 96 large diameter MoM hips using EBRA analysis of plain radiographs and compared this to 3D-CT. All measurements were made using the radiographic definition of cup orientation. The mean difference in version between the two imaging modalities was 8°; with wide limits of agreement of −21.2° and +5.6°. Three retroverted cups were not detected by EBRA. The mean difference in inclination values was 0.3°, but there was up to 9°difference between imaging modalities. When measured by 3D CT, 64% of hips were within a 10° safe zone around 45° inclination and 20° version, compared to only 24% when measured by EBRA (Fishers Exact test, p< 0.0001). The measurement of cup orientation of MoM hips using EBRA software is insufficiently accurate, particularly for the assessment of cup version. The cup rim is obscured by the large diameter femoral head on plain radiographs. Research studies using EBRA analysis for version have limited value if accuracy of more than 20 degrees is required to draw conclusions. This software may not be suitable to measure the performance of a device or surgeon. The limitations of EBRA can be overcome, if 3D-CT with an extended Hounsfield scale for data capture is used

Introduction and Objective. In recent years, along with the extending longevity of patients and the increase in their functional demands, the number of annually performed RSA and the incidence of complications are also increasing. When a complication occurs, the patient often needs multiple surgeries to restore the function of the upper limb. Revision implants are directly responsible for the critical reduction of the bone stock, especially in the shoulder. The purpose of this paper is to report the use of allograft bone to restore the bone stock of the glenoid in the treatment of an aseptic glenoid component loosening after a reverse shoulder arthroplasty (RSA). Materials and Methods. An 86-years-old man came to our attention for aseptic glenoid component loosening after RSA. Plain radiographs showed a complete dislocation of the glenoid component with 2 broken screws in the neck of glenoid. CT scans confirmed the severe reduction of the glenoid bone stock and critical bone resorption and were used for the preoperative planning. To our opinion, given the critical bone defect, the only viable option was revision surgery with restoration of bone stock. We planned to use a bone graft harvested from distal bone bank femur as component augmentation. During the revision procedure the baseplate with a long central peg was implanted “on table” on the allograft and an appropriate osteotomy was made to customize the allograft on the glenoid defect according to the CT-based preoperative planning. The Bio-component was implanted with stable screws fixation on residual scapula. We decided not to replace the humeral component since it was stable and showed no signs of mobilization. Results. The new bio-implant was stable, and the patient gained a complete functional recovery of the shoulder. The scheduled radiological assessments up to 12 months showed no signs of bone resorption or mobilization of the glenoid component. Conclusions. The use of bone allograft in revision surgery after a RSA is a versatile and effective technique to treat severe glenoid bone loss and to improve the global stability of the implant. Furthermore, it represents a viable alternative to autologous graft since it requires shorter operative times and reduces graft site complications. There are very few data available regarding the use of allografts and, although the first studies are encouraging, further investigation is needed to determine the biological capabilities of the transplant and its validity in complex revisions after RSA

Introduction: Management of bone loss during revision total knee arthroplasty (TKA) can be challenging. The degree and location of bone loss often dictates the type of prosthesis that can be utilized during revision surgery. The aim of this prospective study was to determine if plain radiographs are adequate in assessing the degree of bone loss around TKA and identify the limitations of plain radiographs for this purpose, if any. Methods: 205 patients undergoing revision TKA at our institution were included. The indication for revision was aseptic failure in 120 patients and septic failure in the remaining patients. The plain radiographs were evaluated by a research fellow and the attending surgeon. The degree and the location of bone loss around the TKA was determined using the UPenn Bone Loss chart. The degree of real bone loss was then determined intraoperatively. Results: The predicted amount of bone loss for the tibia based on the AP (p=0.136) and lateral (p=0.702) radiographs correlated well with the intraoperative findings. However, plain radio-graphs underestimated the degree of bone loss around femur, particularly the condyles (p=0.005). Discussion: Reconstructive surgeons performing revision TKA need to be aware of the limitations of routine radiographs in assessing the degree of bone loss around the femoral component. Hence, patients undergoing revision TKA with suspected bone loss may need to be evaluated by additional imaging techniques and/or alternative reconstructive options need to be available to deal with greater than expected degree of bone loss intraoperatively

Sensitive and accurate measures of osteolysis around TKR are needed to enhance clinical management and assist in planning revision surgery. Therefore, our aim was to examine, in a cadaver model of osteolysis around TKR, the sensitivity of detection and the accuracy of measuring osteolysis using Xray, CT and MRI. Fifty-four simulated osteolytic lesions were created around six cadaver knees implanted with either a cemented or cementless TKR. Twenty-four lesions were created in the femur and thirty in the tibia ranging in size from 0.7 cm3 to 14 cm3. Standard anteroposterior and lateral fluoroscopically guided radiographs, CT and MRI scans with metal reduction protocols were taken of the knees prior to the creation of lesions and at every stage as the lesion sizes were enlarged. The location, number and size of the lesions from images obtained by each method were recorded. The sensitivity of osteolytic lesion detection was 44% for plain radiographs, 92% for CT and 94% for MRI. On plain radiographs, 54% of lesions in the femur and 37% of lesions in the tibia were detected. None of the six posterior lesions created in the tibia were detected on the AP radiographs; however, three of these six lesions were detected on the lateral radiographs. CT was able to detect lesions of all sizes, except for four lesions in the posterior tibia (mean volume of 1.2 cm3, range 1.06–1.47 cm3). Likewise, MRI was very sensitive in detecting lesions of all sizes, with the exception of three lesions, two of which were in the femur and one was in the medial condyle of the tibia (mean volume of 1.9 cm3, range 1.09–3.14 cm3). Notably, all six posterior tibial lesions, which could not be detected using AP radiographs, were detected by MRI. This study demonstrates the high sensitivity of both CT and MRI (which uses no ionising radiation) to detect simulated knee osteolysis and can therefore be used to detect and monitor progression of osteolysis around TKR. The study also shows the limitations of plain radiographs to assess osteolysis

The aim of this study was to evaluate the rotational axis of the tibia and the association of its axis to tibial coronal alignment after TKR. TKRs were performed using navigated mobile bearing system (40 knees), conventional mobile bearing (48 knees) and conventional fixed bearing (40 knees) and preoperative and postoperative CT scans were assessed using 3D image reconstruction-analysis program. The tibial AP axis which was defined as the line connecting the middle of the PCL and the medial edge of the patellar tendon attachment was measured relative to the AP axis of distal femur preoperatively and postoperatively, as well as the coronal angle of the tibia and posterior slope. The tibial coronal alignments in navigation, postoperative plain radiograph and CT were compared. The AP axis of the tibia was in 2.10° internally rotated position relative to the AP axis of the femur preoperatively and 3.54° postoperatively (range, 19.5° internal rotation to 16.8° external rotation). The coronal angle of the tibia was 0.46° varus on plain radiograph, 0.72° varus on CT, 0.37° valgus in navigation (p=0.005). Posterior slope was 2.53° on plain radiograph and 0.67° in navigation (p< 0.001). There was no correlation between postoperative rotational position of the tibia relative to the femur and the difference in the tibial coronal angle between navigation data and CT. The proposed anteroposterior axis of the tibia centered between 0 to 5 degrees internally rotated position relative to the femur but showed wide range of deviation. The rotation angle of the tibial cutting in navigated TKR did not influence on the postoperative measurement discrepancy between navigation and CT

Aims. The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups. Methods. This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned postioning of the components in both groups. Results. Patients undergoing conventional TKA and robotic TKA had comparable changes in the postoperative systemic inflammatory and localized thermal response at six hours, day 1, day 2, and day 28 after surgery. Robotic TKA had significantly reduced levels of interleukin-6 (p < 0.001), tumour necrosis factor-α (p = 0.021), ESR (p = 0.001), CRP (p = 0.004), lactate dehydrogenase (p = 0.007), and creatine kinase (p = 0.004) at day 7 after surgery compared with conventional TKA. Robotic TKA was associated with significantly improved preservation of the periarticular soft tissue envelope (p < 0.001), and reduced femoral (p = 0.012) and tibial (p = 0.023) bone trauma compared with conventional TKA. Robotic TKA significantly improved the accuracy of achieving the planned limb alignment (p < 0.001), femoral component positioning (p < 0.001), and tibial component positioning (p < 0.001) compared with conventional TKA. Conclusion. Robotic TKA was associated with a transient reduction in the early (day 7) postoperative inflammatory response but there was no difference in the immediate (< 48 hours) or late (day 28) postoperative systemic inflammatory response compared with conventional TKA. Robotic TKA was associated with decreased iatrogenic periarticular soft tissue injury, reduced femoral and tibial bone trauma, and improved accuracy of component positioning compared with conventional TKA. Cite this article: Bone Joint J 2021;103-B(1):113–122

CT- scan as an management tool is being used extensively in managing calcaneal fractures. We set out to see if a CT-scan makes any difference to the management plan as obtained by looking at the plain radiograph. We also looked at the correlation with the actual management. Methodology: This was a retrospective study involving 24 patients with fracture of the calcaneum. These patients had both a plain radiograph and a CT- scan to help decide on management. The actual management that each of these patients had was documented. Three consultants who were blinded to the actual management and names of the subjects were independently asked to grade the radiographs, as operative or non-operative. They were then similarly, asked to decide on operation or no-operation based on blinded CT- scans. The data obtained from the three observers were compared to the actual management and were subjected to statistical analysis. Results: As the data was categorical and matched, the Mcnemars test was used to test the association between the management plan obtained from the radiographs and the management plan obtained from the CT scans, for each consultant. They were also compared with the actual management. The statistical analysis showed that there was no statistically significant association between the management decision obtained from the radiographs and the CT san, for all three observers. Radiograph and CT scan based management decisions also did not correlate with the actual management. Conclusion: The CT scan should only be done when a definite decision is made to operate on a patient, based on plain radiographs. Calcaneal fractures which are decided not to operate, based on X rays, should not have a CT scan as a routine as it provides no valuable additional information

Aims. The purpose of this study was to compare clinical results, long-term survival, and complication rates of stemless shoulder prosthesis with stemmed anatomical shoulder prostheses for treatment of osteoarthritis and to analyze radiological bone changes around the implants during follow-up. Methods. A total of 161 patients treated with either a stemmed or a stemless shoulder arthroplasty for primary osteoarthritis of the shoulder were evaluated with a mean follow-up of 118 months (102 to 158). The Constant score (CS), the Disabilities of the Arm, Shoulder and Hand (DASH) score, and active range of motion (ROM) were recorded. Radiological analysis for bone adaptations was performed by plain radiographs. A Kaplan-Meier survivorship analysis was calculated and complications were noted. Results. The ROM (p < 0.001), CS (p < 0.001), and DASH score (p < 0.001) showed significant improvements after shoulder arthroplasty for both implants. There were no differences between the groups treated with stemmed or stemless shoulder prosthesis with respect to the mean CS (79.2 (35 to 118) vs 74.4 (31 to 99); p = 0.519) and DASH scores (11.4 (8 to 29) vs 13.2 (7 to 23); p = 0.210). The ten-year unadjusted cumulative survival rate was 95.3% for the stemmed anatomical shoulder prosthesis and 91.5% for the stemless shoulder prosthesis and did not differ between the treatment groups (p = 0.251). The radiological evaluation of the humeral components in both groups did not show loosening of the humeral implant. The main reason for revision for each type of arthroplasties were complications related to the glenoid. Conclusion. The use of anatomical stemless shoulder prosthesis yielded good and reliable results and did not differ from anatomical stemmed shoulder prosthesis over a mean period of ten years. The differences in periprosthetic humeral bone adaptations between both implants have no clinical impact during the follow-up. Cite this article: Bone Joint J 2021;103-B(7):1292–1300

Introduction. Plain radiograph underestimates the lysis extent while bone defect determines acetabu-lar revision. We determine the multislice computed tomography (CT) efficacy with metal-artifact minimization to calculate the volume, extent and location of lytic lesions around a loose acetabular cup. Patients and Methods. 48 hips with a loose acetabular cup were evaluated before cup revision. Multislice CT scans with metal-artifact minimization (Toshiba-MEC CT) were done. Scans were taken at 135 kV and 250 mA to maximize the resolution and bone contrast. CT slice thickness was 3 mm and reconstruction index 1.5 mm. Evidence of osteolytic lesion on these scans was compared with plain radiographs and with intraoperative findings. Bone defects were classified according to Paprosky. Results. Acetabular lysis were found in the radiographs of 18 hips and in the CT scans of 36 hips. The most frequent locations of osteolysis were medial (32 hips) and posterior walls (23 hips). Radiographs underestimated the extent of the lysis: there were 28 hips with radiographic type 1 defects and 16 hips with CT defects; 6 and 11 with type 2; 8 and 10 with type 3A; and 6 and 11 with type 3B respectively (Wilcoxon test, p< 0.001). The mean volumetric bone loss was 35.4 cm3 . Intraoperative findings confirmed CT findings. Conclusions. Multislice CT scans with metal-artifact minimization is more sensitive for identifying and quantifying osteolysis around the cup than are plain radiographs. Since CT scans allow us to show the extent and location of the osteolysis, they are useful to plan cup revision

Introduction. Plain radiograph underestimates the lysis extent while bone defect determines acetabular revision. We determine the multislice computed tomography (CT) efficacy with metal-artifact minimization to calculate the volume, extent and location of lytic lesions around a loose acetabular cup. Patients and Methods. 48 hips with a loose acetabular cup were evaluated before cup revision. Multislice CT scans with metal-artifact minimization (Toshiba-MEC CT) were done. Scans were taken at 135 kV and 250 mA to maximize the resolution and bone contrast. CT slice thickness was 3 mm and reconstruction index 1.5 mm. Evidence of osteolytic lesion on these scans was compared with plain radiographs and with intraoperative findings. Bone defects were classified according to Paprosky. Results. Acetabular lysis were found in the radiographs of 18 hips and in the CT scans of 36 hips. The most frequent locations of osteolysis were medial (32 hips) and posterior walls (23 hips). Radiographs underestimated the extent of the lysis: there were 28 hips with radiographic type 1 defects and 16 hips with CT defects; 6 and 11 with type 2; 8 and 10 with type 3A; and 6 and 11 with type 3B respectively (Wilcoxon test, p< 0.001). The mean volumetric bone loss was 35.4 cm3 . Intraoperative findings confirmed CT findings. Conclusions. Multislice CT scans with metal-artifact minimization is more sensitive for identifying and quantifying osteolysis around the cup than are plain radiographs. Since CT scans allow us to show the extent and location of the osteolysis, they are useful to plan cup revision

Purpose: Achieving accurate imaging in talus neck fracture management is important. Patient outcome relies on the ability to achieve and maintain anatomic reduction. The ability to visualize the reduction postoperatively using plain radiographs or computed tomography (CT) is limited. The purpose of this study is to assess the ability of radiostereometric analysis (RSA) to detect changes in talus fracture fragment alignment using an in-vitro model. This will be compared to the use of plain radiographs and CT. Methods: Eight cadaveric human lower extremities were used as talus fracture models. Each talus was removed from the specimen and an osteotomy was created. RSA beads were inserted into the fragments. Anatomical reduction was achieved with two 3.5 mm cortical screws. A set of plain radiographs and RSA films was obtained. The fragments were displaced in a combined varus and supination direction. The degree of displacement was measured with a Vernier caliper and the rotation measured with a protractor. The imaging sequence was repeated in addition to obtaining CT scans with three dimension reconstruction. The RSA measurements were interpreted in a blinded fashion by an experienced researcher. Two independent blinded observers measured the displacement and rotation with plain films and CT. The results from each radiographic measurements were compared using ANOVA method to the experimental values. Results: The average difference between the RSA measurements and the experimental measurements was 5.9mm while the difference between CT scan measurements and experimental values was 2.4mm (p=0.003). The average difference in rotation was not statistically significant between the three groups. Conclusions: CT scan provides the most accurate assessment of talar neck malunion. Unfortunately, RSA is not a viable imaging technique for assessing talar neck displacement. Funding: Other Education Grant. Funding Parties: Lawson Health Research Institute

Aims. We report the clinical results of glenoid osteotomy in patients with atraumatic posteroinferior instability associated with glenoid dysplasia. Patients and Methods. The study reports results in 211 patients (249 shoulders) with atraumatic posteroinferior instability. The patients comprised 63 men and 148 women with a mean age of 20 years. The posteroinferior glenoid surface was elevated by osteotomy at the scapular neck. A body spica was applied to maintain the arm perpendicular to the glenoid for two weeks postoperatively. Clinical results were evaluated using the Rowe score and Japan Shoulder Society Shoulder Instability Score (JSS-SIS); bone union, osteoarthrosis, and articular congruity were examined on plain radiographs. Results. The Rowe score improved from 36 to 88 points, and the JSS-SIS improved from 47 to 81 points. All shoulders exhibited union without progression of osteoarthritis except one shoulder, which showed osteoarthritic change due to a previous surgery before the glenoid osteotomy. All but three shoulders showed improvement in joint congruency. Eight patients developed disordered scapulohumeral rhythm during arm elevation, and 12 patients required additional open stabilization for anterior instability. Conclusion. Good results can be expected from glenoid osteotomy in patients with atraumatic posteroinferior instability associated with glenoid dysplasia. Cite this article: Bone Joint J 2018;100-B:331–7

Summary Statement. Pincer deformities are involved in the genesis of femoro-acetabular impingement (FAI). Radiographic patterns suggestive of pincer deformities are common among general population. Prevalence of the pincer deformities among general population may be overestimated if only plain radiographs are considered. Background. Pincer deformities (coxa profunda, protrusio acetabuli, global retroversion, isolated cranial over-coverage) have been advocated as a cause of femoro-acetabular impingement (FAI) and early hip osteoarthritis (OA). Different radiographic patterns may advocate the presence of a pincer deformity. The prevalence of these radiographic patterns among general adult population, as their role in early hip OA, is poorly defined. Methods. From a database of 40.351 pelvic radiograms and CT collected at our institution between 2005 and 2010, we selected 118 caucasian individuals (56 females, 62 males), aged between 15 and 60 years, who underwent both plain radiographs and CT of the pelvis. A series of exclusion criteria were strictly applied to achieve a sample of adult general population as more representative as possible. In particular patients with presence of any disease involving hip joint, including: advanced hip OA (grade II or III of Tonnis scale), head necrosis, fractures, heterotopic ossifications, bone and soft tissue tumors, rheumatic pathologies, classic hip dysplasia with lateral center-edge angle (L-CEA) less than 20°, clinical diagnosis of FAI or hip pain, were excluded from the present study. We also excluded patients in which open growth plates, osteopenia, hardware or evidence of prior surgery were present. Radiographs were investigated for pelvic tilt, signs of retroversion, lateral center-edge angle (L-CEA), presence of coxa profunda or protrusio acetabuli. EAV was measured on CT scans at the equatorial plane of the acetabulum passing by the 3 o'clock position, while CAV was calculated at a more cranial level corresponding to the 1 o'clock position EAV and CAV were obtained in the axial plane by measuring the angle made by a line connecting the anterior and posterior rims of the acetabulum and a line perpendicular to the line connecting the ischial spines. A new parameter, Acetabular torsion (AT), has been introduced in order to discriminate between global retroversion and isolated cranial over-coverage. AT was defined as the difference between EAV and CAV. Cam deformity was assessed by calculating the alpha angle on the femoral side; an alpha angle > 55° was considered abnormal and suggestive of cam deformity. Radiological signs of chondrolabral degeneration were noticed. Results. Mean EAV and mean CAV were higher in females, mean AA was higher in males. L-CEA, EAV and CAV increased with age. Mean AT was 8.8±6.3. AT was inversely related to CAV (r=−0.799; p<0.0005) but independent from EAV (r=−0.076; p=0.244). EAV≤10.2° was defined as the marker of global retroversion, while AT≥21.2° was defined as the marker of isolated cranial over-coverage. Overall prevalence of pincer deformities was 21.6% (> females; p=0.02). Early OA changes were related to age (p<0.0005) and AA (p<0.0005), but not to pincer deformities (p=0.96). Radiological signs of retroversion showed good or excellent negative predictability but poor positive predictability. Conclusions. Radiographic patterns of pincer deformities are common among general population. Relationship with radiological signs of chondrolabral degeneration is poor. CT allows to discriminate between global retroversion and isolated cranial over-coverage. Prevalence of the pincer deformities among general population may be overestimated if only plain radiographs are considered