Plantar foot soft tissues play a crucial role in absorbing and distributing mechanical stresses during weight-bearing activities. Accurate quantification of their mechanical and morphological properties is essential for understanding load distribution, tissue integrity, and managing conditions like diabetic foot disease. However, the best technique to investigate these properties remains unknown. This systematic review evaluates the clinimetric attributes (i.e. reliability, validity, and repeatability) of existing techniques to identify those most suitable for research and clinical practice. Following PRISMA guidelines, we systematically searched MEDLINE, EMBASE and Web of Science for studies evaluating the mechanical or morphological properties of plantar foot soft tissues. Studies reporting reliability, validity, and/or repeatability of used techniques were evaluated and clinimetric outcomes were interpreted using published cut-off values. Finally, the methodological quality of studies was assessed using the COSMIN Risk of Bias tool. Of 4115 screened studies, 37 were included. Nine techniques to assess mechanical properties (e.g. elastography- and indentation-based techniques, durometer, optical coherence tomography) and six to assess morphological properties (e.g. CT, MRI, ultrasound) were identified. Reliability (29/37 studies) and repeatability (23/37) were frequently reported, while validity assessments were limited (4/37) likely due to the methodological complexity of in-vivo validity assessment, including the absence of an established reference standard for plantar soft tissue mechanics. Inconsistent statistical approaches (26/37) and doubtful blinding (26/37) were the most reported methodological limitations across studies. Only Shear Wave Elastography (SWE) and ultrasound had reliability and validity comprehensively investigated. Ultrasound demonstrated good-to-excellent reliability (ICC = 0.70–0.99) and moderate-to-strong validity (r = 0.5–1.0) using MRI and radiography as reference for measurement of morphological properties. Despite excellent intra-rater reliability (ICC > 0.90) and strong validity (R2 = 0.91) to assess mechanical properties, SWE exhibited systematic measurement bias, likely related to tissue anisotropy, probe pressure, and boundary condition effects. For both techniques, operator-dependent factors (i.e. probe positioning, pressure, inclination, and quantity of coupling gel applied) might influence measurement performance. SWE and ultrasound are currently supported by the most consistent and comprehensive clinimetric evidence among available techniques and emerged as most suitable techniques to quantify the mechanical and morphological properties of plantar foot soft tissues. Nevertheless, heterogeneity in study design, test conditions, and analysis methods limits inter-study and inter-technique comparisons, and highlight the need for more research into clinimetric properties, and into development of more robust and/or valid techniques. Standardized measurement protocols (e.g. probe positioning and pressure, coupling medium, foot positioning) and statistical reporting of clinimetric properties would substantially improve comparability across future studies with potential for future integration into quantitative monitoring approaches for plantar tissue health.

Purpose This study aimed to evaluate triangular fibrocartilage complex (TFCC) appearance on magnetic resonance imaging (MRI) and the correlation between central triangular fibrocartilage (TFC) thickness and ulnar variance (UV) in adolescent asymptomatic gymnasts. Methods This retrospective analysis of a prospective cohort selected 12–18 years old asymptomatic gymnasts and healthy controls from the Physeal MRI study, which is a single-center study on physeal injury that included gymnasts with wrist pain, asymptomatic gymnasts and healthy nongymnasts from June 2015 until November 2017. A standardized scoring form was used for assessment of TFCC morphology on MRI. Bone age and UV were determined on radiographs. TFCC morphology was assessed on 3T MRI and categorized. Statistical differences between groups were calculated using a chi-square test or Fisher exact test. Spearman’s correlation coefficient was calculated between central TFC thickness and calendar/bone age, UV, height, and weight. Correlations were interpreted as poor (≤0.20), fair (0.21–0.40), moderate (0.41–0.60), substantial (0.61–0.80), and excellent (0.81–1.00). Multiple linear regression was performed to determine predictors of central TFC thickness. Results Forty-one adolescents (23 nongymnasts, 18 gymnasts, median age 14 years, 21 female) were included. No differences were found in TFCC appearance. Correlations between central TFC thickness and UV were substantial in both groups. Multiple linear regression analysis showed that UV and bone age together were significant predictors for central TFC thickness in nongymnasts (P < .001). However central TFC thickness could not be predicted by UV and bone age in gymnasts. Conclusions Early gymnastic exposure does not influence TFCC appearance on MRI. However, a misbalance between central TFC thickness and UV appears to exist for adolescent gymnasts and this should be taken into consideration when assessing gymnastic wrist injury. Type of study/level of evidence Diagnostic III

Patient-specific guides improve pedicle screw placement in pediatric deformity surgery, but the preoperative CT entails radiation. Tin-filtered ultra-low-dose CT reduces dose, yet its effect on vertebral segmentation and pedicle screw planning remains unknown. This study therefore assesses geometric agreement between tin-filtered ultra-low-dose CT and standard-dose CT. Five ultra-low-dose and five standard-dose CT scans of one human cadaver were obtained. Vertebrae T2, L2 and S1 were segmented to quantify within- and between-protocol variability of pedicle morphometrics. For planning analysis, screws (T2-S1) were planned on the first standard-dose scan and transferred to the ultra-low-dose segmentations (fixed screw positions). Accuracy was evaluated using the Gertzbein-Robbins scale and screw-to-cortex distances. Pedicle morphometrics differed by ≤ 0.5 mm between protocols, with higher variability on ultra-low-dose CT (CV < 5% for both protocols). After transfer of planned screws from standard-dose to ultra-low-dose segmentations, all remained Gertzbein-Robbins grade A. Ultra-low-dose CT yielded larger screw-to-cortex clearances, with mean absolute differences of 0.14 mm to the medial cortex, 0.21 mm to the superior cortex, and 0.71 mm from screw tip to anterior cortex. Tin-filtered ultra-low-dose CT reduced radiation by > 75%, while preserving sub-millimeter agreement in pedicle morphometrics and screw-to-cortex clearances, suggesting minimal impact on the pedicle screw planning.

The subtalar joint (STJ) is essential for proper foot functioning and fundamental to the biomechanics of this joint is its axis orientation. It is currently unknown how this orientation is altered in cerebral palsy (CP) across the range of foot deformities including varus, planovalgus and midfoot break (MFB). The aim of this study was to quantify STJ axis orientations in children with CP and typically developing (TD) children. In this multicentre study, weight-bearing CT (WBCT) data of participants (21 CP and 9 TD) were collected and foot bone surfaces were segmented. STJ axes were derived from the talar surfaces using shape fitting techniques. STJ axis medial deviation and inclination angles were measured with respect to two anterior/posterior axes, one derived from the tibia and the second from the foot. Significant differences were identified between groups in both medial deviation and inclination angles. Planovalgus feet without MFB exhibited greater medial deviation (26.2±3.2°) and lower inclination angles (18.2 ± 7.3°) than TD feet (medial deviation: 19.4±3.6° and inclination: 25.7 ± 3.8°). Children with MFB had even greater medial deviations (37.7 ± 7.2°) and lower inclinations (-1.7 ± 10.8°) with the mean STJ axis orientation switching to pointing towards the ground. Varus feet had the greatest STJ axis inclination (32.3 ± 7.7°) and the widest range of medial deviations (0.8 ± 21.5°). This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future. This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future.

Injury patterns in children differ from those in adults because of the physiology of the immature skeleton. A tailored imaging approach and in-depth knowledge of the physiology and pathology of the immature musculoskeletal system are essential for diagnosis, guiding the clinician to the right treatment plan and preventing long-term complications. This review provides a comprehensive overview of pediatric sports injuries, structured by tissue type and anatomical region. We pay special attention to the physiology of the immature musculoskeletal system, epidemiology of pediatric sport injuries, advanced imaging techniques, differentiation between normal developmental variants and pathology, and recognition of conditions that may mimic sports injuries. By integrating anatomical insight with clinical relevance, this review offers a modern multidisciplinary guide to the challenges of pediatric sports imaging.

To assess healthcare costs of patients screened for cervical spine (C-spine) fractures using CT, and estimate the change in in-hospital costs if an artificial intelligence (AI) algorithm for C-spine fracture detection would assist the radiologist as concurrent reader. This retrospective, early health technology assessment included 2321 consecutive patients (2007–2014; median age 49 years; 61

BACKGROUND:Visualisation of both soft-tissue and osseous structures is required for optimal cervical spine assessment in patients with cervical radiculopathy. This study investigated whether radiologists considered an MRI-based synthetic CT to be of added value to MRI and X-ray in the assessment of the cervical spine in these patients. METHODS:In this exploratory single-centre, retrospective study that was approved by the local institutional review board (NWMO 190716), three radiologists randomly and independently evaluated two sets of images of 24 patients aged 50 years or older that had received an MRI, X-ray and an MRI-based synthetic CT for cervical radiculopathy, using a questionnaire. Prior to this assessment they received instructions on the questionnaire with a separate test set. Image set 1 consisted of MRI and X-ray, and set 2 of MRI and X-ray, complemented by the synthetic CT. RESULTS:The radiologists reported significantly improved quality of assessment in general and in assessment of cortical delineation, intervertebral joints and neural foramina at C3-4 and C6-7 and presence of posterior lipping, facet arthrosis, bony apposition in the spinal canal when the synthetic CT was presented with MRI and X-ray (median score of 3.8 [IQR 0.2] vs 3.2 [IQR 0.3], p < 0.001). The visibility of trabecular bone was not significantly different between the two sets. CONCLUSIONS:Subjective evaluation by radiologists demonstrated that adding the synthetic cervical spine CT to the MRI and X-ray in patients with cervical radiculopathy could improve the quality of image evaluation and diagnostic confidence, warranting confirmation in larger studies.

Osteomyelitis of the feet is common in persons living with diabetes due to peripheral artery disease, peripheral neuropathy, and increased susceptibility to infection. Although plain radiography is a low-cost and widely available diagnostic tool, its diagnostic performance is limited. Serial radiography may improve the accuracy and clinical utility. This systematic review studies the diagnostic accuracy, limitations, and clinical utility of singular versus serial plain radiography for diagnosing osteomyelitis in the foot in persons with diabetes at diagnosis and follow-up. We conducted PubMed and Embase searches for articles on the diagnostic performance of serial plain radiography for osteomyelitis of the foot in patients with diabetes. Multiple z-tests were used to compare the performance of singular and serial radiographs. Fourteen studies were included, with only one providing original data on serial radiography. The sensitivity of singular radiography ranged from 22% to 93%, and specificity ranged from 22% to 94%. Serial radiography had a sensitivity of 89% and a specificity of 38%. Of the 13 studies, serial radiography outperformed singular radiography in terms of sensitivity in three reports but failed to outperform singular radiography on specificity in any of the reports. The initial examination indicated little advantage of serial radiography over singular radiography for the diagnosis of diabetic foot osteomyelitis. However, a significant exclusion bias exists due to the lack of research in this area. Further research is warranted to clarify the clinical utility of serial radiography.

PURPOSE:There is much conflicting data regarding the anatomy of the anterior tibiofibular ligament (ATiFL), even in studies with anatomical specimens. Therefore, this study aims to reassess the anatomy of this ligament using a high-resolution isotropic 3D-PDw MRI sequence. METHODS:From February to May 2024, 72 MRI scans (3 T) of the ankle were performed at Amsterdam UMC. The inclusion criterion was patients over 16 years of age. The exclusion criteria were absence of a 3D-PDw scan or positive history of ATiFL trauma or surgery, congenital anomalies, metallic or movement artifacts. The 43 3D-PDw valid scans, allowed for aligning the planes along the individual fascicles of the ligament. RESULTS:A total of 43 scans allowed for adequate ligament assessment. The high spatial resolution (0,23 mm) of 3DPDw allowed the identification of three fascicles: superficial, deep, and distal. Regarding dimensions the superficial is the thickest and widest (mean 2.68 x 9.28 mm) and the distal the longest (mean 15.45 mm). Regarding orientation (para-sagittal plane from the fibula to the tibia) the superficial and distal fascicle have a transverse orientation, while the deep fascicle is oriented backward. Regarding the shape, they are fanned in 97.7 %, 71.7 %, and 25.6 % respectively, while they are band-like in the remaining cases. We did not identify any anatomical variance regarding the number of fascicles. CONCLUSION:The use of volumetric isotropic sequences as the 3D-PDw, can be a very useful tool for the anatomical study of ligamentous structures in the absence of available anatomical specimens. Understanding the exact anatomy of this structure is crucial for managing both acute and chronic traumatic pathology.

The anatomy of the wrist and hand is complex due to small and closely opposed bone and soft tissue structures. The complexity of the wrist and hand anatomy simultaneously allows a wide range of motion yet also makes these joints vulnerable to injury. The large number of potentially involved structures can make adequate evaluation of the traumatized wrist challenging. Injury to the wrist or hand is often significant because of the risk of permanent functional impairment.Additionally, traumatic injury can be easily overlooked because signs may be subtle on conventional radiology and satisfaction of search poses risk of incomplete assessment. Other potential factors that create risk of errors in wrist assessment are nonstandardized acquisition, overlooking subtle signs of osseous trauma, neglecting soft tissue trauma, not performing additional imaging despite persistent suspicion of traumatic injury, traumatic injury, and misinterpretation of normal variants and trauma mimics.Thus adequate clinical information on the radiology request is essential to initiate an optimized imaging strategy to detect fractures or dislocations and identify normal variants. This review offers examples of pitfalls when assessing conventional radiographs of the wrist and recommendations on when additional imaging using ultrasound, computed tomography, or magnetic resonance imaging is needed.

BACKGROUND:In clinical practice, currently no standardised approach exists to determine which patients with cervical spine injury (CSI) on CT scan should receive continued cervical spine immobilisation and a neurosurgeon is generally consulted. Insights into the contribution of CT assessment and classification of CSI in determining the need for stabilising therapy could aid in standardising clinical practice in the emergency department. Standardising clinical practice for cervical spine immobilisation could potentially improve the patient flow in the emergency department by reducing delay in decision-making, particularly in hospitals without availability of immediate neurosurgical consultation. Therefore the aim of this study was to investigate if CT assessment and classification of CSI, without clinical information, can determine whether a patients' injury is an injury in need of stabilising therapy (IST). METHODS:In this observational, retrospective study, a database with a multidisciplinary, extensively validated reference standard was used. Consecutive patients screened for CSI using CT (2007-2014) in a level-one trauma centre in the Netherlands were included. Actual therapy that has been provided was compared to the assessment of CSI by three neurosurgeons on CT for presence of ISTs. Clinical information was not provided during initial CT assessment. Injury types were classified according to the AOSpine Injury Classification System. Concordance rates of CT assessment by the neurosurgeons compared to actual therapy provided for presence of ISTs with 95% confidence intervals (95% CI) were calculated. RESULTS:Of the 273 patients in the database with a CSI, 262 were included. CT assessment of CSIs led to assignment as IST in 155/262 cases (59.2%). Based on the actual therapy provided, 124/262 cases (47.3%) were an IST. CT assessment by the neurosurgeons was concordant with the therapy provided for presence of ISTs in 91.9% [95% CI 85.3-95.9%], and for absence of ISTs in 70.3% [95% CI 61.8-77.6%]. After allocation of the AO-subtypes to IST and non-IST, 168/171 (98.2%) of A0-injury subtype cases were non-IST. CONCLUSION:CT scan assessment and injury classification without clinical information allows identification of most injuries in need of stabilising therapy, with a low miss rate of ISTs, particularly for the A0-injury subtype.

BACKGROUND:CT-based load-induced displacement measurements can assist in diagnosing tibial component loosening following total knee arthroplasty (TKA).This involves acquiring two CT-scans of the knee under valgus and varus loads and measuring relative implant-to-tibia displacement through segmentation and registration. However, metal artefacts from the implant vary with its orientation in the CT scanner, affecting measurement accuracy. This study investigated how implant tilt angle and direction impact displacement measurement accuracy. METHODS:A phantom containing a TKA tibial component and a PVC-reference object was scanned at different tilt angles. A neutral scan was acquired with the implant stem aligned along the gantry's central axis (z-axis). The phantom was rotated sidewards (from -40 to + 40° in 10° increments about the CT's y-axis) and forwards/backwards (from -30° to 30° in 10° increments about the CT's x-axis). Image analysis included segmentation and registration between CT scans with different tilts. Three metrics were used: 1) intensity similarity around the implant based on PVC-reference registration (unaffected by metal artefacts), 2) intensity similarity based on implant registration (affected by artefacts), and 3) relative displacement differences between registered implant and PVC-reference, quantified as mean target registration error (mTRE). RESULTS:Intensity similarity decreased with increasing implant tilt, especially when tilt angles crossed the central gantry axis. Implant registration increased intensity similarity but caused positioning errors over 0.5 mm (mTRE) for tilt differences larger than 20°. CONCLUSIONS:Both implant tilt angle and direction influence metal artefact severity, but maintaining consistent alignment helps preserve segmentation quality and registration accuracy, and reliable displacement measurements.

This study aimed to obtain high-resolution 3D isotropic turbo spin-echo (TSE) wrist MRI acquisitions at 7T, with and without fat suppression, facilitated by compressed-sensing (CS) acceleration. In 16 healthy subjects, fat-suppressed (FS) and nonfat-suppressed (NFS) TSE wrist images were obtained. The protocol consisted of a SENSE-accelerated scan, with an isotropic voxel size of 0.45 mm and acquisition time of 7 min ("SENSE45"), a 0.45-mm, 4-min CS-accelerated scan ("CS45"), and a 0.35-mm, 7-min CS-accelerated scan ("CS35"). For two subjects, additional 0.45-mm, 4-min SENSE-accelerated scans were acquired ("High-SENSE"). For the NFS scans, refocusing pulses were optimized to mitigate water-fat chemical-shift artifacts in the slab-selection direction. Anatomical visibility of wrist structures and image quality were assessed qualitatively and through musculoskeletal radiologist grading. The use of nonselective hard refocusing pulses with optimized bandwidths and a center frequency in between water and fat enabled NFS imaging. The image quality of the faster CS45 scans was lower than for SENSE45, with statistically significantly different grading in 9/16 (FS) and 2/6 (NFS) grading parameters. Nonetheless, a similar scan time reduction could not be achieved using High-SENSE. No distinct benefit of CS35 compared to SENSE45 was evident in either the FS or NFS scans. NFS CS35 exhibited enhanced bone sharpness compared to SENSE45 for some subjects, yet on a group level, the difference was not statistically significant. In conclusion, for maintained voxel size, CS presents the opportunity to achieve shorter scan times than possible with SENSE alone, but with reduced image quality. For maintained scan time, although higher resolution CS incidentally showed a promising increase in NFS bone sharpness compared to SENSE, it does not present an unequivocal advantage for 3D 7-T TSE wrist MRI at this stage. Further optimization of the acquisition and reconstruction process is recommended.

BackgroundTotal body cone-beam computed tomography (CBCT) is recently developed for both weight-bearing and non-weight-bearing CT imaging of the spine. Before whole-spine weight-bearing CT is used in clinical practice, potential errors must be addressed, such as the need to stitch multiple volumes due to the field-of-view limitations of CBCT technology.PurposeTo determine the geometric error of fused CBCT images of the spine using automatic stitching software.Material and MethodsIn total, 144 CBCT scans were obtained using three human cadavers. The geometric stitching error was determined in terms of total translation and rotation between vertebrae Th12 and L5, which were positioned in separate image volumes, with a regular spiral CT scan as a reference. The effect of cadaver size, radiation dose, and volume overlap between adjacent CBCT images on the stitching error was determined using Spearman's rank correlation test.ResultsThe median total translation and rotation error were 1.88 mm (interquartile range [IQR] = 1.48-2.42 mm) and 0.54° (IQR = 0.35°-0.63°), respectively. A weak negative correlation between the different volumes of overlap and total translation (r = -0.396; P < 0.001) and rotation (r = -0.319; P < 0.001) was found, as well as a weak positive correlation between the cadaver size and total translation (r = 0.456; P < 0.001).ConclusionThe results of this cadaver study showed stitching errors in the order of 2 mm for translation and 0.5° for rotation in fused CBCT volumes of the spine. These findings function as a relevant step towards the clinical and quantitative application of whole-spine weight-bearing CT imaging.

BACKGROUND:Pediatric pelvic ring fractures are different in biomechanics and anatomy compared with adults. Existing classification systems are insufficient in assessing the mechanical stability of these fractures due to a variety of reasons, leading to a potential underestimation of the injury severity, resulting in suboptimal treatment with the risk of long-term dysfunctions. This study aims to address this problem by comprehensively describing a cohort of patients with pediatric pelvic fractures, identifying specific pediatric pelvic fractures and patterns. METHODS:A retrospective cohort selection of pediatric patients with a pelvic fracture treated in a major level 1 trauma center between 2001 and 2021 was conducted. Fracture patterns were classified using existing systems (Tile, Young and Burgess, Torode and Zieg), with additional parameters such as skeletal maturity considered. In addition, the incidence of specific pediatric fracture characteristics was reviewed. RESULTS:The CT scans of 68 children were reviewed. The median age was 15.5 years, with a majority being female (53%). Traffic accidents were the primary mechanism of injury (65%). Most fractures were classified as Tile type B2 (53%) and Young & Burgess LC3 (32%). SI-joint avulsion fractures were frequently seen (n=14, 21%), predominantly in children with a mature pelvis (n=10, 71%). A significant proportion of fractures did not fit conventional classifications, with little difference between skeletally mature and immature patients (73% vs. 75%). CONCLUSIONS:A large portion of skeletally mature and immature patients cannot be classified according to the currently existing classifications, highlighting the need for a tailored pediatric classification system. APC2-like fracture patterns had a high incidence of SI-joint avulsion fractures, so purely ligamentous APC-fracture patterns are, in our experience, very rare in children. In addition, a previously undescribed fracture pattern (ped-LC3) was identified. Future research is necessary to grasp the full concept of skeletal maturation on the biomechanics and distribution of forces in the pediatric pelvis. LEVEL OF EVIDENCE:Level III.

Lymph node (LN) studies in anti-cyclic citrullinated protein antibodies (ACPA) positive rheumatoid arthritis (RA) patients have revealed notable alterations in adaptive immune cell populations. However, it remains unclear whether similar changes occur in seronegative inflammatory arthritis, such as psoriatic arthritis (PsA) or ACPA-negative RA. This study investigates molecular and cellular alterations in LN biopsies from ACPA-positive RA patients, ACPA-negative inflammatory arthritis (IA) patients, and healthy controls (HCs). Ultrasound-guided LN biopsies were collected from 25 HCs, 14 ACPA positive RA patients and 45 ACPA negative IA patients (including various IA subtypes). Whole LN tissue biopsies were analyzed by transcriptome analyses, quantitative PCR and immunohistochemistry. Distinct LN gene expression profiles were identified in ACPA-positive RA and ACPA-negative IA patients compared to HCs. ACPA-positive RA patients exhibited upregulation of genes associated with adaptive immunity, while ACPA-negative IA patients showed higher expression of genes related to innate immune cell function. Subsequent qPCR analysis confirmed increased mRNA expression of Cathepsin G, a serine protease highly expressed by neutrophils, in ACPA negative IA patients. Immunohistochemistry demonstrated significantly elevated CD15 + neutrophil presence in LNs from IA patients compared to HCs, irrespective of ACPA status and diagnosis (RA or PsA). This study provides novel insights into the immune landscape of lymph nodes in inflammatory arthritis, emphasizing an unexpected role for neutrophils in IA patients. Future research should explore the functional implications of neutrophils within these uninfected lymph nodes to better understand their contribution to the pathogenesis of inflammatory arthritis.

BACKGROUND:This study aimed to provide an overview of the definitions of claw toe and hammertoe deformities as well as the assessment methods used by various specialties to evaluate their presence and severity in both literature and clinical practice. METHODS:A scoping review was conducted using multiple electronic databases to search for articles that contained a definition or assessment method for claw toe or hammertoe deformity. Additionally, orthopedic surgeons, rehabilitation physicians, and podiatrists completed a questionnaire on the definitions and assessment methods they use in clinical practice. RESULTS:Most reported definitions of hammertoe deformity in the literature involved hyperflexion of the proximal interphalangeal joint (PIPJ). Sixteen different definitions were reported. Clinicians varied in their responses: most definitions comprised hyperextension of the metatarsophalangeal joint and hyperflexion of the PIPJ with a varying position of the distal interphalangeal joint. For claw toe deformity, 11 different definitions were found in the literature, and the most common involved hyperextension of the metatarsophalangeal joint with hyperflexion of the PIPJ and distal interphalangeal joint. This was also the most commonly reported definition among clinicians. Quantitative methods for assessing toe deformity were limited, with evaluation relying primarily on visual assessment. CONCLUSIONS:There are a wide variety of definitions and a lack of consensus regarding claw toe and hammertoe deformity in the literature and among various specialty disciplines. Additionally, there are no standardized, validated methods for evaluating the presence and severity of these deformities; observation is primarily used. This hampers effective communication and analysis of toe deformity in clinical practice.

BACKGROUND:Predicting an accurate return to play (RTP) time after hamstring injury remains difficult. The ability of diffusion tensor imaging (DTI) to detect muscle micro-trauma may help to overcome this limitation. PURPOSE:To investigate the predictive value of DTI-derived parameters for RTP prognosis following hamstring injury. MATERIALS AND METHODS:In this single-centre prospective cohort study, athletes with an acute hamstring injury were included. Athletes underwent a 3 T MRI scan of the upper legs, including DTI acquisition within 7 days after injury. DTI parameters were calculated as the relative difference between legs, including the first, second and third eigenvalues, mean diffusivity, radial diffusivity and fractional anisotropy. RTP was defined as the self-reported time needed to return to full unrestricted training in days. Linear regression analysis was performed to determine the association between DTI parameters and RTP. To investigate the added value of DTI to conventional MRI. DTI parameters that met a p < 0.05 threshold in the univariate analyses were selected for multivariate linear regression. In the multivariate linear regression, the selected DTI parameters were individually combined with the conventional modified Peetrons classification. RESULTS:From 116 athletes, 91 were included in the analysis. The median RTP time was 37 days (IQR 41). We found univariate associations between all DTI parameters and the RTP time, explaining between 5.4 % to 15.0 % of the variance in RTP time. Multivariate analysis showed that all DTI parameters except the first eigenvalue were independently associated with RTP time. CONCLUSION:Univariate associations between all six DTI parameters and RTP time were found, explaining between 5.4% and 15% of the variance in RTP time. Multivariate analysis showed DTI parameters that included information on diffusivity in the radial axes had the most added value in RTP prognosis. SUMMARY:In athletes with an acute diagnosis of hamstring injury, multivariate linear regression analysis revealed associations between diffusor tensor imaging-derived parameters (eigenvalues, mean diffusivity, radial diffusivity, and fractional anisotropy) and prognosis for time to return to play prognosis.