Significant changes in lower limb alignment due to flexion and rotation-a systematic 3D simulation of radiographic measurements.

BACKGROUND: Many radiographic lower limb alignment  measurements are dependent on patients' position, which makes a standardised image acquisition of long-leg radiographs (LLRs) essential for valid measurements. The purpose of this study was to investigate the influence of rotation and flexion of the lower limb on common radiological alignment parameters using three-dimensional (3D) simulation. METHODS: Joint angles and alignment parameters of 3D lower limb bone models (n = 60), generated from computed tomography (CT) scans, were assessed and projected into the coronal plane to mimic radiographic imaging. Bone models were subsequently rotated around the longitudinal mechanical axis up to 15° inward/outward and additionally flexed along the femoral intercondylar axis up to 30°. This resulted in 28 combinations of rotation and flexion for each leg. The results were statistically analysed on a descriptive level and using a linear mixed effects model. RESULTS: A total of 1680 simulations were performed. Mechanical axis deviation (MAD) revealed a medial deviation with increasing internal rotation and a lateral deviation with increasing external rotation. This effect increased significantly (p < 0.05) with combined flexion up to 30° flexion (- 25.4 mm to 25.2 mm). With the knee extended, the mean deviation of hip-knee-ankle angle (HKA) was small over all rotational steps but increased toward more varus/valgus when combined with flexion (8.4° to - 8.5°). Rotation alone changed the medial proximal tibial angle (MPTA) and the mechanical lateral distal femoral angle (mLDFA) in opposite directions, and the effects increased significantly (p < 0.05) when flexion was present. CONCLUSIONS: Axial rotation and flexion of the 3D lower limb has a huge impact on the projected two-dimensional alignment measurements in the coronal plane. The observed effects were small for isolated rotation or flexion, but became pronounced and clinically relevant when there was a combination of both. This must be considered when evaluating X-ray images. Extension deficits of the knee make LLR prone to error and this calls into question direct postoperative alignment controls. LEVEL OF EVIDENCE: III (retrospective cohort study).

Computer-Generated Radiographic Measurements of Distal Radius Fractures: Does It Help With Decision Making?

PURPOSE: Operative management of distal radius fractures (DRFs) has become increasingly common. Age, activity levels, and comorbid conditions are major factors influencing the treatment decision, although operative indications are still controversial. Radiographic parameters (RPs), such as radial inclination, dorsal tilt, and articular step-off, can provide objective support for effective decision making. However, manual measurement of RPs may be imprecise and subject to inconsistency. To address this problem, we developed custom software of an algorithm to automatically detect and compute 6 common RPs associated with DRF in anteroposterior and lateral radiographs. The aim in this study was to assess the effect of this software on radiographic interobserver variability among orthopedic surgeons. Our hypothesis was that precise and consistent measurement of RPs will improve radiographic interpretation variability among surgeons and, consequently, may aid in clinical decision making. METHODS: Thirty-five radiograph series of DRFs were presented to 9 fellowship-trained hand and orthopedic trauma surgeons. Each case was presented with basic clinical information, together with plain anteroposterior and lateral radiographs. One of the 2 possible treatment options was selected: casting or open reduction with a locking plate. The survey was repeated 3 weeks later, this time with computer-generated RP measurements. Data were analyzed for interobserver and intraobserver variability for both surveys, and the interclass coefficient, kappa value, was calculated. RESULTS: The interobserver reliability (interclass coefficient value) improved from poor to moderate, 0.35 to 0.50, with the provided RP. The average intraobserver interclass coefficient was 0.68. When participants were assessed separately according to their subspecialties (trauma and hand), improved interobserver variability was found as well. CONCLUSIONS: Providing computed RPs to orthopedic surgeons may improve the consistency of the radiographic judgment and influence their clinical decision for the treatment of DRFs. CLINICAL RELEVANCE: Orthopedic surgeons' consistency in the radiographic judgment of DRFs slightly improved by providing automatically calculated radiographic measurements to them.

Symmetry of bilateral hallux valgus deformity: A radiographic study.

Hallux valgus (HV) is a common anatomical deformity leading to pain and difficulty with footwear and mobility. Bilateral HV deformity is much more common than unilateral although it remains unclear whether the severity of deformity is equal between feet. The objective was to investigate the severity and symmetry of HV in patients with bilateral symptomatic deformity presenting for surgery. Weight-bearing radiographs of patients presenting with symptomatic bilateral HV were reviewed. The hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured and classified as mild, moderate, or severe. Left-to-right comparison was undertaken to assess whether the degree of deformity was similar for each foot. The relationship between age, HVA, and IMA was also assessed. Between July 2014 and June 2020, 322 ft (161 patients with bilateral deformity) underwent corrective HV surgery. Of those, 6.8%, 64.6%, and 28.4% were classified as mild, moderate, and severe, respectively on the left side, and on the right 6.2%, 67.7%, and 26.1% were classified as mild, moderate, and severe respectively. There was no statistically significant difference between feet for either IMA (p = 0.06) or HVA (p = 0.85). There was a moderate correlation (R = 0.41, p ≤ 0.001) between HVA and IMA. There was only a 'weak' or 'very weak' correlation between age and HVA or IMA. Patients presenting for surgery with symptomatic bilateral HV have symmetrical moderate radiographic deformity at the time they present for consideration of surgical intervention.

Correlation between full-thickness degenerative supraspinatus tear and radiographic parameters including the acromiohumeral centre edge angle and the greater tuberosity angle.

BACKGROUND: Many radiographic parameters associated with the extrinsic cause of supraspinatus tears have been proposed. The aim of this study was to assess the relationship between a full-thickness degenerative supraspinatus tear (FTDST) and the patient's radiographic parameters, including the acromiohumeral centre edge angle (ACEA) and the greater tuberosity angle (GTA). METHODS: A retrospective study was conducted. We included 116 patients who underwent shoulder arthroscopic surgery at our institute. The case group included FTDST patients, whereas the control group also included patients without evidence of supraspinatus tears. In each patient, the ACEA and GTA values were measured and analyzed by two independent observers. Intra- and interobserver reliabilities were assessed. Multivariate regression analysis was performed. RESULTS: The ACEA values were significantly increased in the FTDST group with a mean of 26.44° ± 9.83° compared with 16.81° ± 7.72° in the control group (P < 0.001). Multivariate regression analysis also showed that higher ACEA values were associated with an FTDST (odds ratio 1.16 per degree, P = 0.01). For GTA values, a statistically significant difference was found with a mean of 70.92° ± 6.64 compared with 67.84° ± 5.56 in the control group (P = 0.02). However, stepwise regression analysis did not indicate that GTA was a predictor of FTDST. CONCLUSIONS: Our study demonstrated that the presence of increased ACEA values is an independent significant risk factor for the presence of FTDSTs. Consequently, GTA values may be less helpful in assessing the risk of FTDST, especially in this specific population.

Improved identification of unstable acromioclavicular joint injuries in a clinical population using the acromial center line to dorsal clavicle radiographic measurement.

BACKGROUND: Accurate classification and subsequent management of acromioclavicular (AC) joint injuries remains a contentious topic. The updated Rockwood classification acknowledges "stable IIIA" and "unstable IIIB" injuries, a watershed accepted by ISAKOS and important in guiding clinical management. Traditionally, the coracoclavicular distance is used to classify these injuries, despite well-documented limitations. This study aimed to evaluate displacement in AC joint injuries by measuring both coracoclavicular (CC) distance and the newly proposed acromial center line to dorsal clavicle (AC-DC) distance, in a cohort of patients, and correlate the results between the 2 measurements and relationship to Rockwood grade. MATERIALS AND METHODS: Ninety consecutive cases of AC joint injury were evaluated radiographically for Rockwood classification, CC distance on anteroposterior radiographs, and AC-DC distance on Alexander view radiographs. Inter- and intraobserver reliability for each measurement was calculated as well as correlation between the 2 measurement types and the degree to which each measurement accurately represented the Rockwood classification. RESULTS: Although both CC and AC-DC measurements showed very high inter- and intraobserver reliability, the CC distance systematically underestimated the degree of AC joint displacement when compared with the AC-DC measurement as the severity of injury increased, particularly in the presence of posterior horizontal displacement such as that seen in Rockwood IV injuries. CONCLUSION: The AC-DC measurement and use of the Alexander view provides the clinician with a more realistic appreciation of true AC joint displacement, especially in defining watershed cases (ie, IIIA/IIB/IV) and may better inform the decision-making process regarding management options and recommendations.

Relationship Between Hallux Valgus and Pes Planus: Real or Fiction?

Hallux valgus is one of the most common and painful deformities, occurring due to adductor/abductor imbalance of the big toe. Many structural foot disorders have been suggested as the cause of hallux valgus deformity. In this study, we aimed to show the relationship between hallux valgus and pes planus in adult males. A total of 213 patients were included in this study between May 2013 and May 2014. 54 patients with hallux valgus angle (HVA) >20° and intermetatarsal angle (IMA) >9° were evaluated in the case group and 159 patients randomly selected from those admitted for a recent foot ankle trauma with the HVA <15° and IMA <9° were the control group. All patients' HVA, IMA, and talonavicular coverage angle on anteroposterior (AP) foot radiographs and talar-first metatarsal angle (Meary's angle), calcaneal pitch angle, and lateral talocalcaneal angle on lateral foot radiographs were measured. There was no significant difference in talonavicular and Meary's angles between the groups. Calcaneal pitch angle was significantly lower in the case group, whereas talonavicular angle was higher in the control group. Calcaneal pitch angle and lateral talocalcaneal angle showed significant negative correlation with HVA and IMA. There are few reports in the literature about the relationship between pes planus and hallux valgus. Our results strongly showed a high correlation between pes planus and hallux valgus. Further larger patient cohort studies are needed to support our results.

Heart to spine measurements to detect left atrial enlargement in dogs with mitral insufficiency.

BACKGROUND: Radiography is useful to determine left atrial (LA) size when echocardiography is not available. Recently, the authors have described Radiographic Left Atrial Dimension (RLAD) as a new radiographic measurement to assess LA size. The objective of this study was to assess the clinical usefulness of 2 new radiographic measurements to detect and quantify left atrial enlargement (LAE) compared to RLAD and using left atrium to aortic root (LA/Ao) ratio as gold standard. These new measurements, bronchus-to-spine (Br-Spine) and RLAD-to-spine (RLAD-Spine) may be more precise in cases were LA boundaries are not well defined. Fifty dogs, 25 with and 25 without LAE were recruited. Reference LA/Ao ratio was assessed by 2D echocardiography and LAE was considered if LA/Ao > 1.6. Br-spine was measured as a straight vertical line from the main stem bronchus to the ventral border of the vertebra situated immediately dorsal to the heart base. RLAD-Spine was measured from RLAD endpoint perpendicularly to spine. The correlation of RLAD, Br-Spine and RLAD-Spine methods with LA/Ao and their sensitivity and specificity for detecting LAE were calculated. Receiver Operating Characteristic (ROC) curves were used to estimate the optimal cut-off for each method. RESULTS: Correlations between Br-Spine, RLAD-Spine, RLAD and LA/Ao ratio were - 0.66, - 0.76 and 0.89 respectively (P < 0.001). Sensitivity at the optimal cut-off values for detecting LAE were 32.0, 64.0 and 96.0%, respectively. Specificity was 96.0% in all cases. CONCLUSION: Br-Spine and RLAD-Spine were less sensitive radiographic measurements than RLAD in detecting LAE in dogs. Both Br-Spine and RLAD-Spine may not be good alternatives to RLAD.

Radiographic parameters in gravity stress view of the ankle: Normative data.

BACKGROUND: In rotational ankle injury with isolated fibular fracture, deltoid integrity is important for determining stability of ankle. Medial clear space and superior clear space in gravity stress view are parameters widely used to predict deltoid ligament tear. The purpose of this study is to report radiographic parameters in gravity stress view in normal population. METHODS: 120 persons were enrolled. Non weight-bearing ankle mortise and gravity stress view were obtained. Radiographic measurements were made by 2 investigators, including medial clear space (MCS), superior clear space (SCS), tibiofibular overlaps, tibiofibular clear space and talocrural angle. Statistical analysis included mean, mean difference, SD, 95%CI, paired T-test were calculated and subgroup analysis by foot length. Intraclass correlation coefficients were used to determine intra/interobserver reliability of measurement. RESULTS: Mean MCS in gravity stress view was 3.19mm (95%CI 3.1-3.31). This compared to mean MCS of 3.01mm (95%CI 2.9-3.12) in mortise view which was statistically significant (P=0.02). Mean difference was 0.18mm (95%CI 0.07-0.3). SCS in gravity stress view was 3.29mm (95%CI 3.19-3.39) and when compared to MCS in gravity stress view, no statistical significance was found (P=0.158). Mean difference was 0.1mm (95%CI 0.03-0.21). In subgroup analysis by foot length, no significant difference was found in any parameters. CONCLUSIONS: This study provides normative radiographic data for a gravity stress radiograph and supports that if measurable MCS >4mm on gravity stress view, it should be aware of an unstable ankle in supination-external rotation injury.

Periarticular Soft Tissue Envelope Size and Postoperative Wound Complications Following Total Knee Arthroplasty.

BACKGROUND: Periprosthetic joint infection following total knee arthroplasty (TKA) is a serious complication often related to obesity which leads to poor patient outcomes and increased resource utilization. A periarticular soft tissue index (PASTI) may help predict postoperative wound complications than BMI alone. METHODS: Three hundred seventy-six TKA patients with a preoperative, lateral knee X-ray radiograph and 1 year of follow up were analyzed. We used 2 pairs of soft tissue and bony measurements, one referencing the femur and the other the tibia. A high PASTI was defined as a ratio >3.0. Minor complications involved clinical interventions related to the surgical wound. Major complications involved return to the operating room. RESULTS: More minor complications occurred in high PASTI for both tibial (20.9% vs 6.4%; odds ratio 3.89, 95% confidence interval 1.94-7.79, P < .001) and femoral measurements (15.3% vs 7.2%; odds ratio 2.09, 95% confidence interval 1.06-4.15, P = .013). Major complications were also more frequent in high PASTI, though not statistically significant. The proportion of obesity (BMI > 30) in both minor (12.4% vs 7.7%, P = .140) and major complications (2.8% vs 3.3%, P = .788) was not statistically different. CONCLUSION: More wound complications occurred in patients with high PASTI, while no difference was seen using BMI. BMI has traditionally approximated patient size, but does not describe variations in body habitus. PASTI is a more reliable and direct way to assess the periarticular soft tissue envelope size, which is associated with postoperative wound complications in the knee.

A radiographic measurement of left atrial size in dogs.

BACKGROUND: The dimensions of the left atrium in cases with mitral regurgitation are an indirect measurement of its severity. The objective of this study was to evaluate the value of a new radiographic measurement, the radiographic left atrial dimension (RLAD), for detecting left atrial enlargement (LAE) in dogs. Thirty one dogs without LAE and 46 dogs with LAE were recruited in a prospective fashion. Reference left atrium dimension was measured by standard left atrium to aorta ratio (LA/Ao) by 2D echocardiography. LAE was considered if LA/Ao > 1.6. Left atrium dimension was then quantified on lateral radiographs by measuring RLAD. Vertebral heart size (VHS) was measured and RLAD was obtained by drawing a line bisecting the 90 degrees angle defined by the long and short cardiac axes lines of the VHS, up to the dorsal edge of the left atrium and comparing its length to T4's vertebral body length. The correlation of VHS and RLAD methods with LA/Ao was estimated, as well as their sensitivity and specificity for detecting LAE. Receiver Operating Characteristic (ROC) curves were used to estimate the optimal decision criteria for each method. RESULTS: A positive correlation was observed between RLAD and LA/Ao (r = 0.82). RLAD's sensitivity and specificity for detecting LAE when evaluated at the optimal cut-off value, 1.8 vertebrae, were 93.5 and 96.8% respectively. RLAD showed high reproducibility and repeatability. CONCLUSION: RLAD appears to be a clinically useful radiographic measurement for evaluating left atrial dimensions. RLAD would provide clinicians with a simple and cost-effective tool for evaluating and monitoring LAE.

Early radiographic risk factors for rigid relapse in idiopathic clubfoot treated with the Ponseti method.

BACKGROUND: This study aimed at identifying early risk factors for rigid relapse in idiopathic clubfoot using foot radiographs. METHODS: Thirty-four patients with 43 idiopathic clubfeet treated with the Ponseti method were retrospectively reviewed. RESULTS: There were seven rigid relapse recalcitrant to manipulation and requiring extensive soft-tissue release. Three radiograabphic measurements on the maximum dorsiflexion lateral (MD-Lat) radiograph, talocalcaneal (TaloCalc-Lat), tibiocalcaneal (TibCalc-Lat), and calcaneus-first metatarsal (CalcMT1-Lat) angles, showed significant differences between patients with and without rigid relapse. The TaloCalc-Lat and CalcMT1-Lat angles showed significant hazard ratio for rigid relapse by multivariate survival analysis. Clubfeet demonstrating TibCalc-Lat>90° and CalcMT1-Lat<5° have a 24.9-fold odds ratio to develop rigid relapse compared to those demonstrating TibCalc-Lat≤90° or CalcMT1-Lat≥5°. CONCLUSIONS: The TaloCalc-Lat, TibCalc-Lat, and CalcMT1-Lat angles on the MD-Lat radiograph immediately before the tenotomy, probably representing intrinsic tightness of the midfoot and/or hindfoot, are significant risk factors for rigid relapse in patients treated with the Ponseti method.

Measurement of kyphosis and vertebral body height loss in traumatic spine fractures: an international study.

PURPOSE: To investigate whether wide variations are seen in the measurement techniques preferred by spine surgeons around the world to assess traumatic fracture kyphosis and vertebral body height loss (VBHL). METHODS: An online survey was conducted at two time points among an international community of spine trauma experts from all world regions. The first survey (TL-survey) focused on the thoracic, thoracolumbar and lumbar spine, the second survey (C-survey) on the subaxial cervical spine. Participants were asked to indicate which measurement technique(s) they used for measuring kyphosis and VBHL. Descriptive statistics, frequency analysis and the Fisher exact test were used to analyze the responses. RESULTS: Of the 279 invited experts, 107 (38.4 %) participated in the TL-survey, and 108 (38.7 %) in the C-survey. The Cobb angle was the most frequently used for all spine regions to assess kyphosis (55.6-75.7 %), followed by the wedge angle and adjacent endplates method. Concerning VBHL, the majority of the experts used the vertebral body compression ratio in all spine regions (51.4-54.6 %). The most frequently used combination for kyphosis was the Cobb and wedge angles. Considerable differences were observed between the world regions, while fewer differences were seen between surgeons with different degrees of experience. CONCLUSIONS: This study identified worldwide variations in measurement techniques preferred by treating spine surgeons to assess fracture kyphosis and VBHL in spine trauma patients. These results establish the importance of standardizing assessment parameters in spine trauma care, and can be taken into account to further investigate these radiographic parameters.

Radiographic measurement error of the scoliotic curve angle depending on positioning of the patient and the side of scoliotic curve.

BACKGROUND: The Cobb angle measurement is well established for the measurement of coronal deformity aspect of scoliotic curves. The effect of positional differences in relation to the apex side of the scoliosis is not yet fully quantified. While theoretically plausible that positioning error with rotation toward the apex of the scoliosis would decrease the Cobb angle, the relations are not investigated yet and were object of this study. MATERIALS AND METHODS: Multiple measurements of the Cobb angle were performed, while turning a spine-pelvic cadaveric specimen with a right-sided thoracic scoliosis of 47° (in neutral position) from 45° to -45° in steps of 5° using biplanar radiography. Statistical methods were applied to find the critical position, in which measurement errors potentially become clinically relevant (Cobb angle deviation >5°). RESULTS: Turning the specimen to the right (toward the apex of the scoliosis) produced during the first -15° of rotation, a Cobb angle ranging from 47° to 45°. At -20°, the Cobb angle was 42°, at -25° rotation 37° and at -30° rotation 36°. Above -30° rotation, the measured Cobb angle decreased to 36° (77 % of the original Cobb angle). No relevant differences were found by rotating the specimen to the left (away from the apex) (47° at neutral rotation and 44° at maximal error rotation of +45°). CONCLUSION: The influence of rotational misplacement of the patient at the time of image acquisition on Cobb angle measurements is negligible for a rotational misplacement of ±20° of rotation for a idiopathic right-sided thoracic scoliosis of 47°. Over 20° of rotational misplacement of the patient toward the apex of the scoliosis falsely decreases the Cobb angle.

Partially loaded plain radiographic measurement to evaluate rotational alignment in total knee arthroplasty.

PURPOSE: Rotational alignment of prosthetic components after total knee arthroplasty (TKA) is predominantly monitored with computer tomography (CT), for example by relating the anatomical transepicondylar axis (a-TEA) of the native femur to the posterior bicondylar axis of the prosthetic component (PBCA). The purpose of the present study was to portray a reliable, novel plain radiographic method that likewise enables the evaluation of rotational positioning of prosthetic components in TKA. Furthermore, it was intended to evaluate the prosthetic femoro-tibial functional behavior under loaded conditions. METHODS: Modified plain axial radiographs under partial weight bearing (20 kg) were performed in 63 patients (63 knees) after TKA. On the obtained radiographs, all established, relevant anatomic, and prosthetic axis and angles reflecting the rotational position of the femoral (i.e., a-TEA/PBCA angle) and tibial component were detected twice by two independent examiners with an interval of one month. Additionally, in 14 cases with anterior knee pain after surgery, radiographic results were compared to obtained computer tomography images; intraclass coefficients (ICC's) for intra- and inter-rater reliability were calculated. RESULTS: All pre-assigned axis and angles could be identified doubtlessly by both examiners in all investigated knees. For all measurements, ICC's for intra-rater and inter-rater reliability ranged from 0.75 to 0.96. The comparison of the radiographic measurements with corresponding CT results (n = 14) revealed no significant differences (p > 0.05). Rotational alignment of the tibial tray in relation to the native tibial bone was not measurable due to display overlaying. Femoro-tibial behaviour of the prosthetic components under partial loading showed a high variability. CONCLUSION: We were able to establish a new reliable radiographic technique that is able to show the most established and relevant anatomic landmarks and prosthetic axis after TKA to assess the rotational alignment of the prosthetic components in TKA in relation to the distal femur. The evaluation of the femoro-tibal behaviour instead shows a high variability and so far does not allow valid explanatory conclusions.

A new technique for radiographic measurement of acetabular cup orientation.

Accurate radiographic measurement of acetabular cup orientation is required in order to assess susceptibility to impingement, dislocation, and edge loading wear. In this study, the accuracy and precision of a new radiographic cup orientation measurement system were assessed and compared to those of two commercially available systems. Two types of resurfacing hip prostheses and an uncemented prosthesis were assessed. Radiographic images of each prosthesis were created with the cup set at different, known angles of version and inclination in a measurement jig. The new system was the most accurate and precise and could repeatedly measure version and inclination to within a fraction of a degree. In addition it has a facility to distinguish cup retroversion from anteversion on anteroposterior radiographs.

Reliability of a rating scale for assessing alignment of the posterior facet after surgical repair of joint depression fractures of the calcaneus.

Radiographs are frequently used to classify joint depression calcaneal fractures and assess the degree of repair of such injuries. To associate the degree of repair with clinical outcomes such as foot-related quality of life and subjective patient satisfaction, it would be useful to have a valid measuring instrument that has been shown to reliably categorize the alignment of the posterior facet of the calcaneus. To be considered valid, the measurement must have inter-rater and intrarater reliability. In an effort to demonstrate the validity of a coronal plane computed tomographic measurement for categorizing the alignment of the posterior facet after repair of joint depression fractures of the calcaneus, we measured the inter-rater and intrarater reliability of the classification system.

Influence of Fractures and Dislocations in Severity of Rocker-Bottom Deformity in Patients with Charcot Foot.

The objective of this study was to identify bone fractures and joint dislocations that have greater association with the severity of arch collapse in patients with Charcot foot involving the midfoot.A retrospective study in 28 (N = 29 feet) patients who had Charcot foot deformity of the midfoot. The study included stage III of Eichenholtz classification, and Schon classification types I to III. Talar-first metatarsal and calcaneal pitch angles and cuboid height were used to evaluate the severity of the midfoot deformity in a weightbearing lateral radiograph. Two investigators evaluated the bone fracture and joint dislocation involved in weightbearing antero-posterior and lateral radiographs.There were 13 (46%) feet that showed pattern 1, 9 (31%) feet with pattern 2, and 7 (25%) feet with pattern 3 according to the Schon classification. One foot had a combination of patterns 1 and 2. Midfoot ulceration occurred in 64% (n = 19) of feet. In the multivariate analysis, plantarflexion of talar-first metatarsal angle was predicted by navicular-medial cuneiform dislocation (p = .007 [-20.620-3.683]), an increase of the negative calcaneal pitch angle by fragmentation of the cuboid (p = .003 [-15.568-3.626]), and increment of the negative cuboid height by navicular-medial cuneiform and medial cuneiform-first metatarsal dislocations (p = .040 [-12.779-0.317], p = .002 [-13.437-3.267], respectively).Bone fractures and dislocations in the sagittal plane seem to contribute to midfoot collapse, but navicular-medial cuneiform dislocation/non-union and cuboid fragmentation predict severe rocker-bottom deformity in cases of Charcot foot.

Errors in the radiographic measurement of pelvic incidence.

Pelvic incidence (PI) is often quantified in patients undergoing total hip arthroplasty. Errors in radiographic PI measurements can affect clinical outcomes. The purposes of this study were (1) to evaluate the error in radiographic PI measurement in patients with hip osteoarthritis (OA) and (2) to analyze the factors related to the error. Radiographs and computer tomography (CT) images of 100 patients (24 men and 76 women; mean age 63.7 years) with unilateral OA were reviewed. The error in radiographic PI measurement was defined as the difference between the radiographic measurement of the PI (rPI) and the accurate value of PI measured using CT images (cPI). Factors related to the error in the rPI were analyzed, including the coronal and axial rotation of the pelvis on lateral radiographs. The degree of coronal and axial rotation was expressed as the angle of rotation around the anteroposterior and craniocaudal axes. The mean rPI was significantly larger than the cPI (57.8° and 54.1°, p < 0.01). The error in the rPI was 3.6° on average and 15.8° at maximum. The mean coronal and axial rotation of the pelvis was 9.6° and 4.4°, respectively. The error in the rPI positively correlated with coronal pelvic rotation and rPI, and negatively correlated with axial pelvic rotation (p < 0.01, r = 0.35, 0.43, and -0.45, respectively). The rPI was 3.6° larger on average than the cPI in patients with hip OA. Coronal and axial rotation of the pelvis and a large PI were related to the error in the rPI.

Novel radiographic hip fat thickness ratio correlates with early re-operation following total hip arthroplasty.

INTRODUCTION: Obesity is thought to lead to increased failure rates following total hip arthroplasty (THA). Site-specific fat distribution has been suggested to be a better indicator of risk, compared to body mass index. Fat thickness measurement methods were developed for total knee arthroplasty, however, there is limited data on the methods for THA. The aim of this study was to assess the interobserver and intraobserver reliability of a newly defined radiographic subcutaneous fat thickness ratio and investigate the correlation of this ratio with early failure following THA. METHODS: 321 patients who underwent primary THA at a single institution between 2014 and 2017, with at least 1-year of follow-up and a preoperative pelvis anteroposterior x-ray radiograph were included in this study. A high hip fat thickness ratio (HFTR) was arbitrarily defined as ⩾2. Early failure was defined as revision or re-operation for any reason and death related to operation first year following THA. RESULTS: The HFTR was shown to have excellent intraobserver and interobserver reliability. High HFTR was associated with higher risk of early failure following THA (odds ratio 3.8, [95% confidence interval, 1.2-12.1], p < 0.05). The same association persisted when HFTR was analysed as a continuous variable (p < 0.01) and in multivariate analysis (p < 0.05). CONCLUSIONS: HFTR can be used to assess periarticular soft tissue distribution and may be regarded as a useful and reproducible tool for assessing risk of early failure following THA.

Correlation between the Photographic Cranial Angles and Radiographic Cervical Spine Alignment.

The cranial vertical angle (CVA) and cranial rotation angle (CRA) are used in clinical settings because they can be measured on lateral photographs of the head and neck. We aimed to clarify the relationship between CVA and CRA photographic measurements and radiographic cervical spine alignment. Twenty-six healthy volunteers were recruited for this study. Lateral photographs and cervical spine radiographs were obtained in the sitting position. The CVA and CRA were measured using lateral photographs of the head and neck. The C2-7 sagittal vertical axis (SVA), cervical lordosis (C2-7), and occipito-C2 lordosis (O-C2) were measured using radiographic imaging as a standard method of evaluating cervical spine alignment. Correlations between the CVA and CRA on photographs and cervical spine alignment on radiographs were analyzed. The CVA and SVA were significantly negatively correlated (ρ = −0.51; p < 0.05). Significant positive correlations were found between CVA and C2-7 (ρ = 0.59; p < 0.01) and between CRA and O-C2 (ρ = 0.65; p < 0.01). Evaluating the CVA and CRA on photographs may be useful for ascertaining head and neck alignment in the mid-lower and upper parts of the sagittal plane.