Introduction. The correct anteversion of the acetabular cup is critical to achieve optimal outcome after total hip arthroplasty. While number of method has been described to measure the anteversion in plane anteroposterior and lateral radiograph, it is still controversial which method provides best anteversion measurement. While many of the previous studies used CT scan to validate the anteversion measured in plane anteroposterior radiograph, this may cause potential bias as the anteversion measured in CT scan reflects true anteversion while the anteversion measurement methods in plane radiograph are design to measure the planar anteversion. Thus, in the current study, we tried to find the optimal anteversion measurement method free from the previously described bias. Material and method. Custom made cup model was developed which enables change in anteversion and inclination. Simple radiograph was taken with the cup in 10° to 70° degree of inclination at 10° increments and for each inclination angle, anteversion was corrected from 0° to 30° at 5° increments. The radiograph was taken with the beam directed at the center of the cup (mimicking hip centered anteroposterior radiograph) and at 9cm medial to the cup (mimicking pelvis anteroposterior radiograph). The measurements were done by two orthopaedic surgeons using methods described by 1) Pradhan et al, 2) Lewinak et al, 3) Widmer et al, and 4) Liaw et al. For each measurements, the anteversion were compared with the actual anteversion. Result. Interoverver correlation (kappa value) were high in all measurements ranging 0.988 to 0.998. Regardless of how the radiograph was taken, Pradhan method was the most accurate measurement method showing difference of 2.17° ± 1.69° and −2.5° ± 1.93° compare to the actual anteversion respectively for hip centered radiograph and pelvis anteroposterior radiograph. The Widmer method showed the least accuracy (pelvis AP : −6.75° ± 4.62°, hip centered AP : −14.84° ± 4.36°). However, when the anteversion were measured in the safe zone with the inclination in 30° to 50° Liaw's method in hip centered radiograph showed the highest accuracy (1.63° ± 1.4°). Conclusion. The study indicates that the Pradhan's method may provide the most accurate anteversion measurement. However, with the hip in 30° to 50° inclination, Liaw's method measured from hip centred radiograph will provide most accurate anteversion measurement

Aim: To evaluate the radiographs of proximal humeral fractures in an attempt to define a diagnostic sign as a predictor of four-part fracture. Diagnostic sign: The normal humeral head articular surface points towards the glenoid. We describe our ‘sunset’ sign as ‘articular surface of humeral head pointing away from the glenoid and tilted upwards, in the presence of a displaced greater tuberosity fracture’. We postulate that a patient with proximal humerus fracture showing this sign has four-part fracture until proved otherwise. Materials and Methods: Between 2002 and 2006, 80 consecutive patients underwent open reduction and internal fixation of their proximal humeral fractures in our Shoulder unit. We reviewed their preoperative radiographs and operative notes retrospectively. 79 patients were included in the study as one patient’s pre-operative radiograph was not available. The AP radiograph was evaluated independently by three observers who were blinded to the identity of the patients and their operative diagnosis. The presence of ‘sunset’ sign was recorded. There was 90% inter-observer agreement. In the remaining 10%, a consensus review was performed as to the presence of sign for evaluation purpose. The findings were then correlated with the operative findings to confirm whether they were four-part fractures or not. With 95% confidence interval we calculated the sensitivity, specificity, and positive and negative predictive values for our diagnostic sign. Results: 30 out of 79 patients displayed ‘sunset’sign in their preoperative radiograph. Of these 28 had confirmed four-part fractures operatively. The positive predictive value of ‘sunset’ sign in diagnosis the four-part fracture was 93%. The specificity and sensitivity were 95% and 78% respectively. The sensitivity was affected by 8 patients with four part fractures with displaced articular head fragment which had dropped either medially or posteriorly. Conclusion: Our results suggest that in patients with proximal humeral fractures, the presence of ‘sunset’sign in the anteroposterior radiograph is a reliable indicator of four-part fracture

Introduction

When performing a total hip arthroplasty (THA), some surgeons routinely perform an intraoperative anteroposterior (AP) pelvis radiograph to assess components. The purpose of this study was to evaluate the reliability of the intraoperative radiograph to accurately reflect acetabular inclination, leg length, and femoral offset as compared to the immediate postoperative supine AP radiograph.

BACKGROUND:. Although most radiographs used for polyethylene wear measurements have been taken with the patient in the supine position in order to assess penetration by the femoral head into the acetabular polyethylene socket, we have questioned the effect of weight-bearing on the position of the head within the socket. The current study aimed to determine the effect of weight bearing, i.e. standing on the two-dimensional radiographic position of the femoral head within the socket. PATIENTS AND METHODS:. A total of three hundred and fifty patients (three hundred and eighty three hips) who had had a total hip arthroplasty had digital radiographs made a set of anteroposterior radiographs for each patient: one radiograph was made with the patient supine and one was made with the patient standing in full weight bearing on the replaced hip. The patients were divided into the following two groups: 1) seventy-five patients (eighty-three hips) with conventional polyethylene (CON) (group-1); 2) two hundred and seventy-five patients (three hundred hips) with highly cross-linked polyethylene (XPL) (group-2). The set of radiograph was taken at three weeks postoperatively and at the time of semiannual follow-up. The average ceramic femoral head penetration was measured with radiographs taken in the standing or supine position at the final follow-up and compared with those of three weeks postoperatively. A single researcher with use of a computerized measurement system performed all measurements on the radiographs of the two-dimensional position of the head. Follow-up period were 13.5 ± 1.0 (range. 11.0–15.5) years in group-1 and 7.6 ± 2.1 (range. 5.0–12.6) years in group-2. RESULTS:. Linear penetration rates in group-1 were 0.172 ± 0.069 mm/year in supine position and 0.178 ± 0.069 mm/year in standing position (p < 0.05, paired t-test; r. 2. = 0.88), and the rates in group-2 were 0.029 ± 0.024 mm/year and 0.035 ± 0.027 mm/year respectively (p < 0.0005, paired t-test; r. 2. = 0.16). The mean ceramic head penetration rate in XPL socket showed 80 to 83% reduction compared with those in CON. CONCLUSIONS:. We found significant difference between the average total ceramic femoral head penetration between supine and standing radiographs in using both CON and XPL socket. Standing radiographs were useful and recommended for polyethylene socket wear measurements. Figure legend. Fig. Wear measurement: With use of a computerized measurement system, the thickness of the polyethylene socket (a) was measured along a line connecting the center of the ceramic femoral head to the outer border of the socket at its shortest distance. The wear rate was determined by comparing the thickness in the latest follow up radiograph with the thickness in the initial postoperative radiograph at the same location. Each radiographically measured value was corrected for magnification by a factor derived from comparing the diameter of the ceramic head on the radiograph (b) with its known diameter of 22.225 mm

This study aimed to assess the effect of flexion and external rotation on measurement of femoral offset (FO), greater trochanter to femoral head centre (GT-FHC) distance, and neck shaft angle (NSA). Three-dimensional femoral shapes (n=100) were generated by statistical shape modelling from 47 CT-segmented right femora. Combined rotations in the range of 0–50° external and 0–50° flexion (in 10° increments) were applied to each femur after they were neutralised (defined as neck and proximal shaft axis parallel with detector plane). Each shape was projected to create 2D images representing radiographs of the proximal femora.

As already known, external rotation resulted in a significant error in measuring FO but flexion alone had no impact. Individually, neither flexion nor external rotation had any impact on GT-FHC but, for example, 30° of flexion combined with 50°of external rotation resulted in an 18.6mm change in height. NSA averaged 125° in neutral with external rotation resulting in a moderate increase and flexion on its own a moderate decrease. However, 50° degrees of both produced an almost 30 degree increase in NSA.

In conclusion, although the relationship between external rotation and FO is appreciated, the impact of flexion with external rotation is not. This combination results in apparent reduced FO, a high femoral head centre and an increased NSA. Femoral components with NSAs of 130° or 135° may historically have been based on X-ray misinterpretation. This work demonstrates that 2D to 3D reconstruction of the proximal femur in pre-op planning is a challenge.

Aims. To evaluate whether low-intensity pulsed ultrasound (LIPUS) accelerates bone healing at osteotomy sites and promotes functional recovery after open-wedge high tibial osteotomy (OWHTO). Methods. Overall, 90 patients who underwent OWHTO without bone grafting were enrolled in this nonrandomized retrospective study, and 45 patients treated with LIPUS were compared with 45 patients without LIPUS treatment in terms of bone healing and functional recovery postoperatively. Clinical evaluations, including the pain visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score, were performed preoperatively as well as six weeks and three, six, and 12 months postoperatively. The progression rate of gap filling was evaluated using anteroposterior radiographs at six weeks and three, six, and 12 months postoperatively. Results. The pain VAS and JOA scores significantly improved after OWHTO in both groups. Although the LIPUS group had better pain scores at six weeks and three months postoperatively, there were no significant differences in JOA score between the groups. The lateral hinge united at six weeks postoperatively in 34 (75.6%) knees in the control group and in 33 (73.3%) knees in the LIPUS group. The progression rates of gap filling in the LIPUS group were 8.0%, 15.0%, 27.2%, and 46.0% at six weeks and three, six, and 12 months postoperatively, respectively, whereas in the control group at the same time points they were 7.7%, 15.2%, 26.3%, and 44.0%, respectively. There were no significant differences in the progression rate of gap filling between the groups. Conclusion. The present study demonstrated that LIPUS did not promote bone healing and functional recovery after OWHTO with a locking plate. The routine use of LIPUS after OWHTO was not recommended from the results of our study. Cite this article: Bone Jt Open 2022;3(11):885–893

The current standard of practice following knee arthroplasty is to demonstrate the appropriate alignment of knee replacements using knee radiographs. Recent studies have suggested that standard knee radiographs provide adequate accuracy for tibial prosthesis alignment assessment as compared with long knee view radiographs which are more technically demanding and carry greater radiation exposure. In this study, we aim to address whether alignment measured on standard knee radiographs are reliable and reproducible over time. We examined a cohort of 80 patients 37 male (46%), 43 females (54%), mean age = 68 years) who underwent total knee arthroplasty (TKA). Standard knee anteroposterior radiographs performed within 2 days following surgery were compared to standard knee anteroposterior radiographs taken 1 year following the surgery in patients with well-functioning prosthesis. Tibial prosthesis alignment angles between the longitude of the tibial shaft and the tibial baseplate were calculated using Centricity Enterprise Web V3.0 software. The data was examined using R software. In well-functioning primary knee arthroplasties, tibial prosthesis alignment angles measured in the 1-year follow-up standard view knee radiographs were found to deviate from measurements obtained with the same radiographic specifications in the immediate post-operative period. A significant mean percentage difference was found between the two radiographs. Long knee view radiographs may be required in order to accurately assess tibial prothesis alignment following total knee arthroplasty

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

Aims. Limited implant survival due to aseptic cup loosening is most commonly responsible for revision total hip arthroplasty (THA). Advances in implant designs and materials have been crucial in addressing those challenges. Vitamin E-infused highly cross-linked polyethylene (VEPE) promises strong wear resistance, high oxidative stability, and superior mechanical strength. Although VEPE monoblock cups have shown good mid-term performance and excellent wear patterns, long-term results remain unclear. This study evaluated migration and wear patterns and clinical and radiological outcomes at a minimum of ten years’ follow-up. Methods. This prospective observational study investigated 101 cases of primary THA over a mean duration of 129 months (120 to 149). At last follow-up, 57 cases with complete clinical and radiological outcomes were evaluated. In all cases, the acetabular component comprised an uncemented titanium particle-coated VEPE monoblock cup. Patients were assessed clinically and radiologically using the Harris Hip Score, visual analogue scale (pain and satisfaction), and an anteroposterior radiograph. Cup migration and polyethylene wear were measured using Einzel-Bild-Röntgen-Analyze software. All complications and associated treatments were documented until final follow-up. Results. Clinical assessment showed persistent major improvement in all scores. On radiological assessment, only one case showed a lucent line (without symptoms). At last follow-up, wear and migration were below the critical thresholds. No cup-related revisions were needed, indicating an outstanding survival rate of 100%. Conclusion. Isoelastic VEPE cups offer high success rates and may prevent osteolysis, aseptic loosening, and the need for revision surgeries in the long term. However, longer follow-up is needed to validate our findings and confirm the advantages offered by this cup. Cite this article: Bone Jt Open 2024;5(10):825–831

The primary treatment goal for patients with femoroacetabular impingement syndrome, a common hip condition in athletes, is to improve pain and function. In selected patients, in the short term following intervention, arthroscopic hip surgery is superior to a pragmatic NHS- type physiotherapy programme. Here, we report the three-year follow-up results from the FemoroAcetabular Impingement Trial (FAIT), comparing arthroscopic hip surgery with physiotherapy in the management of patients with femoroacetabular impingement (FAI) syndrome. Two-group parallel, assessor-blinded, pragmatic randomised controlled study across seven NHS England sites. 222 participants aged 18 to 60 years with FAI syndrome confirmed clinically and radiologically were randomised (1:1) to receive arthroscopic hip surgery (n = 112) or physiotherapy and activity modification (n = 110). We previously reported on the hip outcome score at eight months. The primary outcome measure of this study was minimum Joint Space Width (mJSW) on Anteroposterior Radiograph at 38 months post randomisation. Secondary outcome measures included the Hip Outcome Score and Scoring Hip Osteoarthritis with MRI (SHOMRI) score. Minimum Joint Space Width data were available for 101 participants (45%) at 38 months post randomisation. Hip outcome score and MRI data were available for 77% and 62% of participants respectively. mJSW was higher in the arthroscopy group (mean (SD) 3.34mm (1.01)) compared to the physiotherapy group (2.99mm (1.33)) at 38 months, p=0.017, however this did not exceed the minimally clinically important difference of 0.48mm. SHOMRI score was significantly lower in the arthroscopy group (mean (SD) 9.22 (11.43)) compared to the physiotherapy group (22.76 (15.26)), p-value <0.001. Hip outcome score was higher in the arthroscopy group (mean (SD) 84.2 (17.4)) compared with the physiotherapy group (74.2 (21.9)), p-value < 0.001). Patients with FAI syndrome treated surgically may experience slowing of osteoarthritisprogression and superior pain and function compared with patients treated non- operatively

Introduction. Wolff's Law proposes that trabecular bone adapts in response to mechanical loading and that trabeculae align with the trajectory of predominant loads. The current study is aimed to investigate trabecular orientation in the tibia in patients with osteoarthritis of the knee. Consistent with Wolff's Law, it was hypothesised that orientation would reflect the mechanical loading of the joint and hence that there would be a correlation between the trabecular orientation and the mechanical axis of the lower limb. Methods. 51 anonymised radiographs from patients with osteoarthritis were analysed using ImageJ (National Institute of Health). Each patient had both a standard anteroposterior radiograph of the knee and a long leg view taken while weight bearing. For each anteroposterior radiograph, the angle of the femoral shaft and tibial shaft were measured. The femoral shaft – tibial shaft (FS -TS) angle was then calculated as the difference between the two, as described by Sheehy et al. (2011). A medial rectangle was selected with the top, bottom, medial and lateral borders being the sclerotic bone, the growth line, the bone edge and the centre of the medial tibial spine. Corresponding measurements were done on the lateral side. Trabecular orientation of both areas was measured using OrientationJ (an ImageJ plugin). In all cases the medial and lateral orientation angles were expressed relative to the angle of the tibial shaft. The mechanical axis of the lower limb was measured from the full length radiographs by calculating the angle formed by the femoral and tibial axes, as described by Goker and Block. All measurements were done independently by two observers, SAS and SL. Results. Except where indicated, the results are based on analysis of 51 radiographs. Inter-tester analysis indicated excellent reliability (ICC = 0.99) for the mechanical axis measurement and preliminary inter-tester analysis (based on 25 radiographs) indicated good reliability for the orientation measurements (ICC = 0.76). The FS-TS angle calculated from the anteroposterior radiographs was significantly correlated with the mechanical axis calculated from the full-leg views (r = 0.96, p < 0.01), with an average offset of 5.7°, which is consistent with previous research. There was a significant correlation between the lateral trabecular orientation and both the FS-TS angle measured from the anteroposterior radiographs (r = −0.48, p < 0.01) (Figure) and the mechanical axis measured from the long leg views (r = −0.39, p < 0.01). There was also a significant correlation between the medial trabecular orientation and the FS-TS angle (r = 0.35, p = 0.01). Discussion. There were significant correlations between leg alignment (both the mechanical axis and the FS − TS angle) and trabecular orientation in the human tibia. These findings were consistent with Wolff's Law, which proposes that trabecular bone adapts in response to mechanical loading. To the best of our knowledge, the current study is the first to investigate in vivo trabecular orientation in the human tibia and to establish a correlation with the mechanical axis of the lower limb. The findings also suggest that inspection of the trabecular orientation might provide valuable information on leg alignment and mechanical loading prior to surgery

Shoulder arthroplasty humeral stem design has evolved to accommodate patient anatomy characteristics. As a result, stems are available in numerous shapes, coatings, lengths, sizes, and vary by fixation method. This abundance of stem options creates a surgical paradox of choice. Metrics describing stem stability, including a stem's resistance to subsidence and micromotion, are important factors that should influence stem selection, but have yet to be assessed in response to the diametral (i.e., thickness) sizing of short stem humeral implants. Eight paired cadaveric humeri (age = 75±15 years) were reconstructed with surgeon selected ‘standard’ sized short-stemmed humeral implants, as well as 2mm ‘oversized’ implants. Stem sizing conditions were randomized to left and right humeral pairs. Following implantation, an anteroposterior radiograph was taken of each stem and the metaphyseal and diaphyseal fill ratios were quantified. Each humerus was then potted in polymethyl methacrylate bone cement and subjected to 2000 cycles of 90º forward flexion loading. At regular intervals during loading, stem subsidence and micromotion were assessed using a validated system of two optical markers attached to the stem and humeral pot (accuracy of <15µm). The metaphyseal fill ratio did not differ significantly between the oversized and standard stems (0.50±0.06 vs 0.50±0.10; P = 0.997, Power = 0.05); however, the diaphyseal fill ratio did (0.52±0.06 vs 0.45±0.07; P < 0.001, Power = 1.0). Neither fill ratio correlated significantly with stem subsidence or micromotion. Stem subsidence and micromotion were found to plateau following 400 cycles of loading. Oversizing stem thickness prevented implant head-back contact in all but one specimen with the least dense metaphyseal bone, while standard sizing only yielded incomplete head-back contact in the two subjects with the densest bone. Oversized stems subsided significantly less than their standard counterparts (standard: 1.4±0.6mm, oversized: 0.5±0.5mm; P = 0.018, Power = 0.748;), and resulted in slightly more micromotion (standard: 169±59µm, oversized: 187±52µm, P = 0.506, Power = 0.094,). Short stem diametral sizing (i.e., thickness) has an impact on stem subsidence and micromotion following humeral arthroplasty. In both cases, the resulting three-dimensional stem micromotion exceeded, the 150µm limit suggested for bone ingrowth, although that limit was derived from a uniaxial assessment. Though not statistically significant, the increased stem micromotion associated with stem oversizing may in-part be attributed to over-compacting the cancellous bed during broaching, which creates a denser, potentially smoother, interface, though this influence requires further assessment. The findings of the present investigation highlight the importance of proper short stem diametral sizing, as even a relatively small, 2mm, increase can negatively impact the subsidence and micromotion of the stem-bone construct. Future work should focus on developing tools and methods to support surgeons in what is currently a subjective process of stem selection

Aims. The frequency of severe femoral retroversion is unclear in patients with femoroacetabular impingement (FAI). This study aimed to investigate mean femoral version (FV), the frequency of absolute femoral retroversion, and the combination of decreased FV and acetabular retroversion (AR) in symptomatic patients with FAI subtypes. Methods. A retrospective institutional review board-approved observational study was performed with 333 symptomatic patients (384 hips) with hip pain due to FAI evaluated for hip preservation surgery. Overall, 142 patients (165 hips) had cam-type FAI, while 118 patients (137 hips) had mixed-type FAI. The allocation to each subgroup was based on reference values calculated on anteroposterior radiographs. CT/MRI-based measurement of FV (Murphy method) and AV were retrospectively compared among five FAI subgroups. Frequency of decreased FV < 10°, severely decreased FV < 5°, and absolute femoral retroversion (FV < 0°) was analyzed. Results. A significantly (p < 0.001) lower mean FV was found in patients with cam-type FAI (15° (SD 10°)), and in patients with mixed-type FAI (17° (SD 11°)) compared to severe over-coverage (20° (SD 12°). Frequency of decreased FV < 10° was significantly (p < 0.001) higher in patients with cam-type FAI (28%, 46 hips) and in patients with over-coverage (29%, 11 hips) compared to severe over-coverage (12%, 5 hips). Absolute femoral retroversion (FV < 0°) was found in 13% (5 hips) of patients with over-coverage, 6% (10 hips) of patients with cam-type FAI, and 5% (7 hips) of patients with mixed-type FAI. The frequency of decreased FV< 10° combined with acetabular retroversion (AV < 10°) was 6% (8 hips) in patients with mixed-type FAI and 5% (20 hips) in all FAI patients. Of patients with over-coverage, 11% (4 hips) had decreased FV < 10° combined with acetabular retroversion (AV < 10°). Conclusion. Patients with cam-type FAI had a considerable proportion (28%) of decreased FV < 10° and 6% had absolute femoral retroversion (FV < 0°), even more for patients with pincer-type FAI due to over-coverage (29% and 13%). This could be important for patients evaluated for open hip preservation surgery or hip arthroscopy, and each patient requires careful personalized evaluation. Cite this article: Bone Jt Open 2022;3(7):557–565

Shoulder arthroplasty is effective at restoring function and relieving pain in patients suffering from glenohumeral arthritis; however, cortex thinning has been significantly associated with larger press-fit stems (fill ratio = 0.57 vs 0.48; P = 0.013)1. Additionally, excessively stiff implant-bone constructs are considered undesirable, as high initial stiffness of rigid fracture fixation implants has been related to premature loosening and an ultimate failure of the implant-bone interface2. Consequently, one objective which has driven the evolution of humeral stem design has been the reduction of stress-shielding induced bone resorption; this in-part has led to the introduction of short stems, which rely on metaphyseal fixation. However, the selection of short stem diametral (i.e., thickness) sizing remains subjective, and its impact on the resulting stem-bone construct stiffness has yet to be quantified. Eight paired cadaveric humeri (age = 75±15 years) were reconstructed with surgeon selected ‘standard’ sized and 2mm ‘oversized’ short-stemmed implants. Standard stem sizing was based on a haptic assessment of stem and broach stability per typical surgical practice. Anteroposterior radiographs were taken, and the metaphyseal and diaphyseal fill ratios were quantified. Each humerus was then potted in polymethyl methacrylate bone cement and subjected to 2000 cycles of compressive loading representing 90º forward flexion to simulate postoperative seating. Following this, a custom 3D printed metal implant adapter was affixed to the stem, which allowed for compressive loading in-line with the stem axis (Fig.1). Each stem was then forced to subside by 5mm at a rate of 1mm/min, from which the compressive stiffness of the stem-bone construct was assessed. The bone-implant construct stiffness was quantified as the slope of the linear portion of the resulting force-displacement curves. The metaphyseal and diaphyseal fill ratios were 0.50±0.10 and 0.45±0.07 for the standard sized stems and 0.50±0.06 and 0.52±0.06 for the oversized stems, respectively. Neither was found to correlate significantly with the stem-bone construct stiffness measure (metaphysis: P = 0.259, diaphysis: P = 0.529); however, the diaphyseal fill ratio was significantly different between standard and oversized stems (P < 0.001, Power = 1.0). Increasing the stem size by 2mm had a significant impact on the stiffness of the stem-bone construct (P = 0.003, Power = 0.971; Fig.2). Stem oversizing yielded a construct stiffness of −741±243N/mm; more than double that of the standard stems, which was −334±120N/mm. The fill ratios reported in the present investigation match well with those of a finite element assessment of oversizing short humeral stems3. This work complements that investigation's conclusion, that small reductions in diaphyseal fill ratio may reduce the likelihood of stress shielding, by also demonstrating that oversizing stems by 2mm dramatically increases the stiffness of the resulting implant-bone construct, as stiffer implants have been associated with decreased bone stimulus4 and premature loosening2. The present findings suggest that even a small, 2mm, variation in the thickness of short stem humeral components can have a marked influence on the resulting stiffness of the implant-bone construct. This highlights the need for more objective intraoperative methods for selecting stem size to provide guidelines for appropriate diametral sizing. For any figures or tables, please contact the authors directly

Background. Disruption of the normal relationship between the proximal tibia and fibula is seen in a number of different conditions such as skeletal dysplasias and post-infective deformity, as well as the consequence of lengthening procedures. Radiographic indices for the tibio-fibular relationship at the ankle have been described, but no similar measures have been reported for the proximal articulation. Aim. The purpose of this study was to investigate the normal radiographic relationship between the proximal tibia and fibula in children to determine the normal range and variation. Methods. Our radiology database was used to identify a sample of 500 normal anteroposterior radiographs of paediatric knees. All radiographs were reviewed by a single observer. The distance from the corner of the lateral tibial plateau to both the proximal tibial (PT) and fibular physes (PF) were measured, and a ratio of the two calculated (PF/PT). The process was repeated with a sample of 100 radiographs by the same observer, and a second independent observer in order to calculate intra-and inter-observer reliability. Results. The age range of patients in this study was 4–16 years, with mean age 12.7. The mean PF/PT ratio was 1.7 (standard deviation 0.2, range 1.3–2.0). Intra-observer reliability was 100% and inter-observer reliability was 97.8%. Conclusion. The results of this study demonstrate that in the normal paediatric knee, there is a consistent relationship between the position of the proximal tibial and fibular physes, with a small range of variation. The PF/PT ratio is a simple and reliable way of assessing the relationship between the proximal tibia and fibula in children, using a standard anteroposterior radiograph. This ratio could be very useful in the diagnosis and planning of surgical management of a number of different causes of tibial and fibular deformities in children

Introduction. A comprehensive understanding of pelvic orientation prior to total hip arthroplasty is necessary to allow proper cup positioning and mitigate the risks of complications associated with component malpositioning. Measurements using anteroposterior (AP) radiographs have been described as effective means of accurately predicting pelvic orientation. The purpose of our study was to describe the inter- and intra-observer reliability and predictive accuracy of predicting pelvic tilt using AP radiographs. Methods. Five fellowship-trained orthopaedic surgeons independently analyzed pelvic tilt, within 10 degrees, for 50 different AP pelvis radiographs. All surgeons were blinded to patient information, diagnosis, and correct measurements prior to analysis. Responses were then compared to correct measurements using sitting-standing AP and lateral stereoradiographs. Results. The average correct predictive value of pelvic tilt between all surgeons was 54%. The intra-observer accuracy of predicting pelvic tilt ranged from 48% to 64%. Discussion. Pelvic tilt cannot be accurately predicted using anteroposterior radiographs. Pre-operative evaluation of pelvic parameters requires multiple views for detailed assessment. Therefore, lateral radiographs are required for accurate prediction of pelvic tilt

Aims. Leg length discrepancy (LLD) is a common pre- and postoperative issue in total hip arthroplasty (THA) patients. The conventional technique for measuring LLD has historically been on a non-weightbearing anteroposterior pelvic radiograph; however, this does not capture many potential sources of LLD. The aim of this study was to determine if long-limb EOS radiology can provide a more reproducible and holistic measurement of LLD. Methods. In all, 93 patients who underwent a THA received a standardized preoperative EOS scan, anteroposterior (AP) radiograph, and clinical LLD assessment. Overall, 13 measurements were taken along both anatomical and functional axes and measured twice by an orthopaedic fellow and surgical planning engineer to calculate intraoperator reproducibility and correlations between measurements. Results. Strong correlations were observed for all EOS measurements (r. s. > 0.9). The strongest correlation with AP radiograph (inter-teardrop line) was observed for functional-ASIS-to-floor (functional) (r. s. = 0.57), much weaker than the correlations between EOS measurements. ASIS-to-ankle measurements exhibited a high correlation to other linear measurements and the highest ICC (r. s. = 0.97). Using anterior superior iliac spine (ASIS)-to-ankle, 33% of patients had an absolute LLD of greater than 10 mm, which was statistically different from the inter-teardrop LLD measurement (p < 0.005). Discussion. We found that the conventional measurement of LLD on AP pelvic radiograph does not correlate well with long leg measurements and may not provide a true appreciation of LLD. ASIS-to-ankle demonstrated improved detection of potential LLD than other EOS and radiograph measurements. Full length, functional imaging methods may become the new gold standard to measure LLD. Cite this article: Bone Jt Open 2022;3(12):960–968

Introduction and Objective. Up to 30% of thoracolumbar (TL) fractures are missed in the emergency room. Failure to identify these fractures can result in neurological injuries up to 51% of the casesthis article aimed to clarify the incidence and risk factors of traumatic fractures in China. The China National Fracture Study (CNFS. Obtaining sagittal and anteroposterior radiographs of the TL spine are the first diagnostic step when suspecting a traumatic injury. In most cases, CT and/or MRI are needed to confirm the diagnosis. These are time and resource consuming. Thus, reliably detecting vertebral fractures in simple radiographic projections would have a significant impact. We aim to develop and validate a deep learning tool capable of detecting TL fractures on lateral radiographs of the spine. The clinical implementation of this tool is anticipated to reduce the rate of missed vertebral fractures in emergency rooms. Materials and Methods. We collected sagittal radiographs, CT and MRI scans of the TL spine of 362 patients exhibiting traumatic vertebral fractures. Cases were excluded when CT and/or MRI where not available. The reference standard was set by an expert group of three spine surgeons who conjointly annotated (fracture/no-fracture and AO Classification) the sagittal radiographs of 171 cases. CT and/or MRI were used confirm the presence and type of the fracture in all cases. 302 cropped vertebral images were labelled “fracture” and 328 “no fracture”. After augmentation, this dataset was then used to train, validate, and test deep learning classifiers based on the ResNet18 and VGG16 architectures. To ensure that the model's prediction was based on the correct identification of the fracture zone, an Activation Map analysis was conducted. Results. Vertebras T12 to L2 were the most frequently involved, accounting for 48% of the fractures. Accuracies of 88% and 84% were obtained with ResNet18 and VGG16 respectively. The sensitivity was 89% with both architectures but ResNet18 had a significantly higher specificity (88%) compared to VGG16 (79%). The fracture zone used was precisely identified in 81% of the heatmaps. Conclusions. Our AI model can accurately identify anomalies suggestive of TL vertebral fractures in sagittal radiographs precisely identifying the fracture zone within the vertebral body

Aims. The Coronal Plane Alignment of the Knee (CPAK) classification has been developed to predict individual variations in inherent knee alignment. The impact of preoperative and postoperative CPAK classification phenotype on the postoperative clinical outcomes of total knee arthroplasty (TKA) remains elusive. This study aimed to examine the effect of postoperative CPAK classification phenotypes (I to IX), and their pre- to postoperative changes on patient-reported outcome measures (PROMs). Methods. A questionnaire was administered to 340 patients (422 knees) who underwent primary TKA for osteoarthritis (OA) between September 2013 and June 2019. A total of 231 patients (284 knees) responded. The ­Knee Society Score 2011 (KSS 2011), Knee injury and Osteoarthritis Outcome Score-12 (KOOS-12), and Forgotten Joint Score-12 (FJS-12) were used to assess clinical outcomes. Using preoperative and postoperative anteroposterior full-leg radiographs, the arithmetic hip-knee-ankle angle (aHKA) and joint line obliquity (JLO) were calculated and classified based on the CPAK classification. To investigate the impact on PROMs, multivariable regression analyses using stepwise selection were conducted, considering factors such as age at surgery, time since surgery, BMI, sex, implant use, postoperative aHKA classification, JLO classification, and changes in aHKA and JLO classifications from preoperative to postoperative. Results. The preoperative and postoperative CPAK classifications were predominantly phenotype I (155 knees; 55%) and phenotype V (73 knees; 26%), respectively. The change in the preoperative to postoperative aHKA classification was a significant negative predictive factor for KOOS-12 and FJS-12, while postoperative apex proximal JLO was a significant negative predictive factor for KSS 2011 and KOOS-12. Conclusion. In primary TKA for OA, preoperative and postoperative CPAK phenotypes were associated with PROMs. Alteration in varus/valgus alignment from preoperative to postoperative was recognized as a negative predictive factor for both KOOS-12 and FJS-12. Moreover, the postoperative apex proximal JLO was identified as a negative factor for KSS 2011 and KOOS-12. Determining the target alignment for each preoperative phenotype with reproducibility could improve PROMs. Cite this article: Bone Joint J 2024;106-B(10):1059–1066

Introduction. Intraoperative assessment of coronal alignment is important when performing corrective osteotomies around the knee and ankle, limb lengthening and trauma surgery. The Joint Angle Tool (JAT) provides surgeons with information about the anatomic and mechanical axes intraoperatively based on true anteroposterior radiographs. Aim: Presentation of the JAT, a low-cost goniometer for intraoperative assessment of the lower limb alignment. Materials and Methods. The JAT consists of pre-printed joint orientation angles of the anatomic and mechanical axis including normal variations on a plastic sheet. It is placed on the screen of the image intensifier after obtaining a true anterior-posterior image. The pre-printed joint orientation angles can intraoperatively assist the surgeons in achieving the pre-planned axis correction. Here, its feasibility is demonstrated in four cases. Results. Here, we present the intraoperative use of JAT in four cases:. 77 mm femoral bone transport due to non-union utilizing a bone transport nail,. distal femoral osteotomy correcting coronal and torsional malalignment using a retrograde intramedullary trauma nail,. proximal / high tibial open wedge osteotomy with an intramedullary implant correcting varus malalignment in a hypophosphatemic rickets patient, and. a supramalleolar, closing wedge osteotomy realigning the anatomic axis with a plate and screws. Conclusions. The JAT is a modified goniometer which allows intraoperative assessment of the mechanical and anatomic axis. JAT is applicable throughout the entire surgical procedure irrespective of the method of internal fixation and may provide additional reassurance of correct alignment. The JAT consists of a plastic sheet with printed joint orientation angles and their normal variation. JAT is freely available from . profeedback.dk/JAT/JAT.pdf. for use and modification according to Creative Commons license (CC BY-SA 4.0)