Operative treatment of isolated epiphyseal fracture of the distal fibula: 1 case report and literature review.

Pediatric ankle injuries are common; ankle epiphyseal fractures are also common in children. But isolated distal epiphyseal fibular fractures of the distal fibula are clinically rare. We describe one unusual case of an adolescent with a completely displaced Salter-Harris type II distal fibular epiphyseal fracture. The attempt of closed reduction failed, and the patient required open reduction and internal fixation. The localized periosteum and the superior peroneal retinaculum were avulsed from the distal fibular metaphysis, with the peroneal tendons underneath exposed but no obvious subluxation. To the best of our knowledge, this combination of injuries has not been previously reported.

Overuse Injury of the Epiphyseal Primary Physis.

Year-round participation in youth sport that involves high levels of repetitive movement fosters an environment in which overuse injuries are likely to occur. Epiphyseal primary physeal stress injuries (PSIs), unique to skeletally immature athletes, are a particular concern, given their potential for growth disturbance. Initially observed in Little League baseball players, these injuries are now known to affect the long bones around the shoulder, elbow, wrist, hand, knee, ankle, and foot of skeletally immature athletes involved in a variety of sport activities.This article offers an epidemiological and radiologic perspective on the extent and distribution of epiphyseal PSIs in youth sport. We also review a novel framework for understanding the pathophysiologic mechanisms causing these injuries. This information is essential for the early identification of epiphyseal PSIs and devising preventive measures that can reduce a delayed diagnosis and long-term morbidity. Preventing and reducing injury to the epiphyseal growth plates is essential because impairment and dysfunction can result in lifelong morbidity and a risk of premature osteoarthritis.

[Fractures around the knee in children : Epiphysiolysis and physeal fractures of the distal femur and proximal tibia]. / Frakturen rund um das Knie im Wachstumsalter : Epiphysiolysen und epiphysäre Frakturen des distalen Femurs und der proximalen Tibia.

Epiphysiolysis and epiphyseal fractures of the distal femur and proximal tibia are an extremely rare entity, but due to their far-reaching consequences with associated functional restrictions of the knee joint, they must be recognized and treated thoroughly. Complete and correct diagnosis is essential and, diagnostically speaking and in addition to standard x­rays in two planes, the threshold for cross-sectional imaging examination techniques should be low. A conservative treatment attempt is possible for undisplaced fractures, but surgical retention and stabilization using wires and screws is usually indicated. Growth disorders often and inevitably occur after such injuries. Clinical monitoring of complications only ends once growth is complete.

Bone Age Determination of Epiphyseal Fusion at Knee Joint and Its Correlation with Chronological Age.

Background and Objectives: Bone age determination is a valuable method for forensic and disaster identifications of unknown human remains, as well as for medical and surgical procedural purposes. This retrospective research study aimed to determine the age based on epiphyseal fusion stages and investigate differences related to gender. Materials and Methods: X-rays of the knee were collected from medical imaging centers in hospitals in the south of Jordan and examined by two observers who determined the bone epiphyseal phase of closure for the femur, tibia, and fibula bone ends close to the knee based on a three-stage classification. Results: The main results revealed that females showed earlier epiphyseal union (Stage II) at the lower end of the femur and the upper ends of the tibia and fibula compared to males. In males, the start of complete union (Stage III) at knee bones was seen at the age of 17-18 years, while in females, it was seen at the age of 16-17 years. Additionally, knee bones showed complete union in 100% of males and females in the age groups 21-22 years and 20-21 years, respectively. Although females showed an earlier start and end of epiphyseal complete union than males, analysis of collected data showed no significant age differences between males and females at the three stages of epiphyseal union of the knee bones. Conclusions: Findings of the radiographic analysis of bone epiphyseal fusion at the knee joint are a helpful method for chronological age determination. This study supports the gender and ethnicity variation among different geographical locations. Studies with a high sample number would be needed to validate our findings.

Microwave Ablation of the Pig Growth Plate: Proof of Concept for Minimally Invasive Epiphysiodesis.

BACKGROUND: Different surgical methods for epiphysiodesis of limb length discrepancy (LLD) have been described. Although these methods are variably effective, they are associated with morbidity (pain and limp) and potential complications. Microwave ablation is a less-invasive opportunity to halt growth by selectively destroying the growth plate via thermal energy to treat LLD in children. QUESTIONS/PURPOSES: In this proof-of-concept study using an in vivo pig model, we asked: (1) What is the durability of response 2 to 4 months after microwave ablation of the tibial growth plate as measured by length and angulation of the tibia via a CT scan? (2) Was articular cartilage maintained as measured by standard histologic staining for articular cartilage viability? METHODS: To develop an in vivo protocol for microwave ablation, we placed microwave antennas adjacent to the proximal tibia growth plate in the cadaveric hindlimbs of 18 3-month-old pigs. To determine the suitable time, we varied ablation from 90 to 270 seconds at 65-W power settings. After sectioning the tibia, we visually assessed for discoloration (implying growth plate destruction) that included the central growth plate but did not encroach into the epiphysis in a manner that could disrupt the articular surface. Using this information, we then performed microwave ablation on three live female pigs (3.5 to 4 months old) to evaluate physiologic changes and durability of response. A postprocedure MRI was performed to ensure the intervention led to spatial growth plate alterations similar to that seen in cadavers. This was followed by serial CT, which was used to assess the potential effect on local bone and growth until the animals were euthanized 2 to 4 months after the procedure. We analyzed LLD, angular deformity, and bony deformity using CT scans of both tibias. The visibility of articular cartilage was compared with that of the contralateral tibia via standard histologic staining, and growth rates of the proximal tibial growth plate were compared via fluorochrome labeling. RESULTS: Eighteen cadaveric specimens showed ablation zones across the growth plate without visual damage to the articular surface. The three live pigs did not exhibit changes in gait or require notable pain medication after the procedure. Each animal demonstrated growth plate destruction, expected limb shortening (0.8, 1.2, and 1.5 cm), and bony cavitation around the growth plate. Slight valgus bone angulation (4º, 5º, and 12º) compared with the control tibia was noted. No qualitatively observable articular cartilage damage was encountered from the histologic comparison with the contralateral tibia for articular cartilage thickness and cellular morphology. CONCLUSION: A microwave antenna placed into a pig's proximal tibia growth plate can slow the growth of the tibia without apparent pain and alteration of gait and function. CLINICAL RELEVANCE: Further investigation and refinement of our animal model is ongoing and includes shorter ablation times and comparison of dynamic ablation (moving the antennae during the ablation) as well as static ablation of the tibia from a medial and lateral portal. These refinements and planned comparison with standard mechanical growth arrest in our pig model may lead to a similar approach to ablate growth plates in children with LLD.

Correcting for asymmetry of the proximal tibial epiphysis is warranted to determine postoperative alignment deviations in kinematic alignment from planned alignment of the tibial component on the native tibia.

BACKGROUND: In total knee arthroplasty, unrestricted kinematic alignment aims to restore pre-arthritic lower limb alignment and joint lines. Joint line orientations of the contralateral healthy proximal tibia might be used to evaluate accuracy of tibial component alignment post-operatively if asymmetry is minimal. Our objective was to evaluate left-to-right asymmetry of the proximal tibial epiphysis in posterior tibial slope and varus-valgus orientation as related to unrestricted kinematic alignment principles. METHODS: High resolution CT images (0.5 mm slice thickness) were acquired from bilateral lower limbs of 11 skeletally mature subjects with no skeletal abnormalities. Images were segmented to generate 3D tibia models. Asymmetry was quantified by differences in orientations required to shape-match the proximal epiphysis of the mirror 3D tibia model to the proximal epiphysis of the contralateral 3D tibia model. FINDINGS: Systematic and random differences (i.e. mean ± standard deviation) in tibial slope and varus-valgus orientation were - 0.8° ± 1.2° and - 0.2° ± 0.8°, respectively. Ninety five percent confidence intervals on the means included 0° indicating that systematic differences were minimal. INTERPRETATION: Since random differences due to asymmetry are substantial in relation to random surgical deviations from pre-arthritic joint lines previously reported, post-operative computer tomograms of the contralateral healthy tibia should not be used to directly assess accuracy of tibial component alignment on a group level without correcting for differences in tibial slope and varus-valgus orientation due to asymmetry.

Bone age assessment based on different MRI modalities of the proximal humerus epiphysis: the comparisons of T1WI, T2WI, and PDWI.

Bone age assessment (BAA) is crucial in various fields, including legal proceedings, athletic competitions, and clinical medicine. However, the use of X-ray methods for age estimation without medical indication is subject to ethical debate, especially in forensic and athletic fields. The application of magnetic resonance imaging (MRI) with non-ionizing radiation can overcome this limitation in BAA. This study aimed to compare the application value of several MRI modalities of proximal humeral in BAA. A total of 468 patients with shoulder MRIs were retrospectively collected from a Chinese Han population aged 12-30 years (259 males and 209 females) for training and testing, including T1 weighted MRI (T1WI), T2 weighted MRI (T2WI), and Proton density weighted MRI (PDWI). Optimal regression models were established for age estimation, yielding mean absolute error (MAE) values below 2.0 years. The MAE values of T1WI were the lowest, with 1.700 years in males and 1.798 years in females. The area under the curve (AUC) and accuracy values of different MRI modalities of 16-year and 18-year thresholds were all around 0.9. For the 18-year threshold, T1WI outperformed T2WI and PDWI. In conclusion, the three MRI modalities of the proximal humerus can serve as reliable indicators for age assessment, while the T1WI performed better in age assessment and classification.

Adolescent idiopathic scoliosis: is there a relationship between Risser staging and the proximal humerus ossification system?

PURPOSE: To evaluate whether there is a mismatch between Risser staging and the proximal humerus ossification system (PHOS); and to analyze the correlation in the skeletal maturity stages between the two humeral epiphyses. METHODS: Data from patients aged 10 to 18 years with adolescent idiopathic scoliosis (AIS) seen between 2018 to 2021 were analyzed. In an anteroposterior (AP) spine radiograph the ossification process was evaluated using the Risser classification method and bilateral PHOS (if both humeral epiphyses were visualized). A mismatch between methods was defined as a Risser 0-1 (relatively skeletally immature) with a PHOS 4-5 (skeletally mature), or a Risser 2-5 (relatively skeletally mature) with a PHOS 1-3 (skeletally immature). The McNemar test was used to calculate the significance of the mismatch. RESULTS: A mismatch between Risser and PHOS stages was observed in 28.5% of 105 patients, which was statistically significant (p < 0.001). Of the 49 patients with a Risser 0-1, 55.1% (n = 27) had a PHOS 4-5. None of the patients with a Risser 2-5 had a PHOS 1-3. In the 47 patients in whom both humeri were visualized, the absolute correlation between the left and right PHOS values was 95.7%. CONCLUSION: Of AIS patients who are relatively skeletally immature according to Risser staging, more than half may be skeletally mature when measured with PHOS. In patients with a Risser 0-1, it is recommended to measure skeletal maturity in an AP spine radiograph using the PHOS method, which may more accurately guide treatment decision-making, without the need to visualize both humeral epiphyses in this radiographic projection. LEVEL OF EVIDENCE: IV.

Forensic age estimation of the knee by post-mortem DR, CT, and MR imaging: a comparative study.

It is believed by many that reference data for age estimation purposes must be imaging-modality specific. A study from our department has however proven otherwise. We therefore found it interesting to investigate this further by looking at the level of agreement between different imaging modalities. The aim of this study was to investigate the level of agreement between the three radiological modalities, computed tomography (CT), magnetic resonance imaging (MRI), and digital radiography (DR), in assessing the ossification of the epiphyses of the knee. A total of 34 deceased individuals of 10-25 years of age, brought in for a medicolegal autopsy at our department, were scanned by CT, MRI, and DR. The ossification stages of the three bones of the right knee, distal femoral, proximal tibial, and proximal fibular epiphysis were assessed using the established combined staging method by Schmeling et al. and Kellinghaus et al. Analysis of the results by Cohen's weighted kappa showed a good agreement between CT and DR (K = 0.61-0.70), and MRI and DR (K = 0.68-0.79) but only moderate agreement between CT and MRI (K = 0.55-0.57). This leads us to conclude that different radiological images cannot be used interchangeably for age estimation purposes, so reference material needs to be imaging-modality specific. However, to make a more general conclusion research on a larger population is needed.

The transphyseal osteotomy for the slipped proximal tibial epiphysis in tibia vara.

This study aimed to describe a novel transphyseal osteotomy (TPO) for acute deformity correction in children with bilateral tibia vara and the atraumatic 'slipped proximal tibial epiphysis' (SPTE) entity. We described the clinical and radiological findings in five children (10 limbs) with tibia vara that were treated with the TPO. The criteria for the SPTE were met in nine (9/10) cases. The surgical technique and short-term results of the TPO are reported. The median age was 9 years (range, 6-9), with obesity (BMI > 95th centile) present in all children. The medial tibial plateau was not significantly depressed (the median angle of depression of the medial plateau measured 30° (range, 20°-32°). The mean medial proximal tibial angle of 33° (range, 8°-71°) was corrected to 82° (range, 77°-86°), the mean anatomic posterior proximal tibial angle of 48° (range, 32°-70°) was corrected to 72° (range, 61°-86°), and the median internal tibial rotation of 45° (range, 20°-50° internal rotation) was corrected to neutral rotation (range, 10° internal-10° external rotation). There were two complications: one case of recurrent deformity and one case of intra-articular extension of the osteotomy. We describe a novel TPO that aims to simultaneously correct all aspects of the deformity, stabilise the physis, and prevent recurrence through epiphysiodesis. Further research is required to determine its efficacy and safety. The atraumatic SPTE appears to represent a specific morphological presentation in tibia vara. Level of evidence: 4.

Age estimation based on the metamorphosis of the clavicle end: A test of Falys and Prangle method in two contemporary samples.

Upon finding skeletal unidentified remains, four are the questions that must be answered: age, sex, ancestry, and stature. Regarding age estimation, clavicle has received special attention because medial epiphysis is the last epiphysis, among long bones that ossifies. Falys and Prangle proposed a method of age estimation based on three degenerative characteristics-surface topography (TOP), Porosity (POR) and Osteophyte formation (OST)-evaluated on the sternal end of the clavicle according to the descriptions and the illustrations provided in the original article producing satisfactory results. The current study aims to test the applicability of the Falys' and Prangle's method on 174 individuals from two contemporary samples, one from Greece (Cretan osteological Collection and Athens Forensic Anthropology Lab collection) and one from Thailand (Osteological collection in Chiang Mai). Composite scores were calculated, inter and intra- observer error were estimated by kappa statistics and regression equations of the original study were tested in our sample and in subsamples divided by sex and population. The Greek sample gave more accurate estimates compared to the Thai sample. Regressions of known sex gave slightly better results in most cases. When individuals <40 years old were excluded, classification increased for both Thai and Greeks. The results of this pilot study indicate that there are morphological features on the clavicle that are highly correlated with age. Thus, there is a scope of expanding research on the morphological features of the collar bone.

The Relationship between the Bevel of the Radial Head Epiphysis and the Posterior Synovial Fringe During Rotation of the Elbow: An Ultrasonography Study with Possible Implications Regarding the Pathophysiology of Nursemaid's Elbow.

BACKGROUND: Nursemaid's elbow is the most common upper extremity injury in children under 5 years of age. However, the exact pathomechanism underlying the nursemaid's elbow remains elusive, and approximate one-third of patients present with a nonclassical history. Using a high-frequency ultrasound probe, we attempted to determine the relationship between the anterior edge of the posterior synovial fringe and the peripheral rim of the radial head epiphysis during rotation. It is possible that the primary reason for the nursemaid's elbow is due to the pronator position. METHODS: Twenty-one patients had a history of nursemaid's elbow and had a successful reduction before enrollment in this study. A high-frequency linear array 6 to 24 MHz hockey stick transducer was used to detect small morphologic changes in the peripheral rim of the radial head epiphysis and the posterior synovial fringe during rotation of the capitellum-radial joint. RESULTS: In complete pronation, the anterior edge of the posterior synovial fringe contacts the beveled articular surface of the radial head peripheral rim in all 21 patients. In neutral and complete supination, the anterior edge of the posterior synovial fringe contacts the convexly nonarticular surface of the radial head peripheral rim and extends deep into the foveal radius. The posterior synovial fringe and the capsule-aponeurotic membrane were tightened in passive pronation in all 21 cases. The posterior synovial fringe and the capsule-aponeurosis membrane were all loose in the neutral and supination positions. CONCLUSION: The anterior edge of the posterior synovial fringe touches the beveled peripheral rim of the radial head epiphysis during complete pronation, and the tension of the lateral collateral ligament complex during pronation may further cause unstable conditions of the anterior edge of the posterior synovial fringe. We hypothesized that the beveled peripheral rim of the radial epiphysis and its relationship with the anterior edge of the posterior synovial fringe could be the reason why nursemaid's elbow only occurs while the elbow is in the pronator position.

Pediatric primary lymphoma of bone in epiphysis case report.

Primary lymphoma of the bone (PLB) is a rare entity, with a majority of pediatric cases presenting in the metaphysis of long bones. There have been only seven reported cases to date of pediatric lymphoma of the bone arising from the epiphysis, of which only two have been described in the proximal tibia. We report a pediatric case of PLB in the tibial epiphysis which presented initially with knee pain. Imaging was performed with X-ray, MRI, CT, and PET-CT with bone biopsies revealing diffuse large B-cell lymphoma. This patient also showed a second, synchronous lesion in the left iliac bone, which was also biopsy proven to diffuse large B-cell lymphoma. Lymphoma in the epiphysis for children is rare and often confused with infectious etiologies or other types of tumors. Misdiagnosis may result in inappropriate treatment and possible progression of the disease, thus making early identification important to initiate therapy.

Femoro-Epiphyseal Acetabular Roof Index Values on Anteroposterior Pelvic Radiographs Significantly Increase With Hip Adduction and Decrease With Abduction.

PURPOSE: To investigate the impact of hip adduction and abduction on the femoro-epiphyseal acetabular roof (FEAR) index using conventional anteroposterior pelvic radiographs of patients with borderline hip dysplasia (BHD). METHODS: Patients with BHD (lateral center edge angle [LCEA] with values of 18° ≤ LCEA <25°) and who were subject to periacetabular osteotoym were selected from a consecutive retrospective cohort from January 2009 to January 2016. The hip ad-/abduction (adduction handled as negative values) and the FEAR index (lateral opening angles handled as positive values) were measured in the initially standardized acquired pelvic radiographs. Thereafter, using surgical planning software, different degrees of hip adduction and abduction were simulated from 20° of adduction to 30° of abduction, and the FEAR index was measured at each position. Pearson correlation was used to identify a potential correlation between the hip ad-/abduction and the FEAR index. RESULTS: Eighty-nine hips were included. Initial radiographs showed unintentional mean ad-/abduction of -5.3° ± 3.1° (range, -14° to 2°). The mean FEAR index at the initial ad-/abduction angle was -3.6° ± 7.2° (range, -18.0° to 16.0°) and was significantly different from neutral position (0° of ad-/abduction) -9.2° ± 7.0° (range, -27.0° to 10.0°) (P < .001). The FEAR index was negatively correlated to the hip ad-/abduction angle (r = 1, P < .001), with lower values for the FEAR index with the hip in abduction. CONCLUSIONS: Significant differences in FEAR index measurements were observed depending on hip ad-/abduction on pelvic radiographs. A linear change of the FEAR index of 5° per 5° of hip adduction or abduction could be demonstrated, with adduction resulting in increasing and abduction in decreasing values for the FEAR index. LEVEL OF EVIDENCE: Level III, diagnostic study.

Forensic age estimation with ankle MRI: Evaluating distal tibial and calcaneal epiphyseal fusion.

Forensic authorities often request age estimation from forensic experts, particularly in cases related to sexual abuse, child pornography, illegal migration, marriage, etc. The most commonly used method in this regard is radiological methods. Because of the potential dangers of radiation exposure outside of clinical indications, new researches are focusing on non-ionizing and non-invasive technologies. This study aimed to demonstrate the applicability of age estimation in living individuals from ankle magnetic resonance images as a non-ionizing method, and to determine whether it is compatible with individuals' real ages and to establish a database. Ankle MRI images of patients aged between 7 and 26 years who applied to the Cukurova University Faculty of Medicine Balcali Hospital between January 2011 and December 2020 were retrospectively evaluated. A six-stage staging method proposed by Lu et al. was applied to the distal tibial and calcaneal epiphyseal ossification points by examining ankle MRI images of a total of 331 patients, 197 males and 134 females. In the study, images obtained from a sagittal section fast spin echo T1-weighted sequence, with a section thickness of 3-4 mm, were evaluated. As a result of the study, Stage 1 in both distal tibial and calcaneal epiphysis was observed only in patients under 18 years of age in both sex. In males, stage 2 in distal tibial epiphyseal ossification was observed under 18 years of age, except for one case, and stage 5 in both distal tibial and calcaneal epiphyseal ossification was observed in almost all cases over 18 years of age in males. According to the results of our study, magnetic resonance imaging was found to be a non-ionizing method that could be used in addition to other radiological methods aimed at determining the 18-year age limit in age estimation. Multicenter, comparative, and prospective studies conducted by experienced researchers are needed to enable the routine use of MRI in age estimation.

The accuracy of Cameriere methods in Turkish children: chronological age estimation using developing teeth and carpals and epiphyses of the ulna and radius.

The aim of the present study was to develop a specific formula by measuring the developing teeth, carpal bones, and epiphyses of the ulna and radius to determine the chronological age in Turkish children. The left developing permanent mandibular teeth were evaluated, and the number of teeth with closed apex was recorded. The distance between the inner sides of open apex/apices was measured by using the ImageJ program and divided by the tooth length. The sum of the normalized open apices was also calculated. The carpal area (Ca), covering the epiphyses of ulna and radius and the carpal bones, was measured on the X-rays of left hand. The areas of each carpal bone and epiphyses of the ulna and radius were measured, and these measurements were added together to obtain the bone area (Bo). The Bo/Ca ratio between the total area of carpal bones and the carpal area was calculated to normalize the measurements. The accuracy of the equations formulated by Cameriere was evaluated, and a new regression equation was developed accordingly. The new formula showed no statistically significant difference between the chronological and the estimated age for females, males, and total sample. The new formula, which hit the age with 72.80% accuracy, was more successful in predicting chronological age than other adjusted regression equations. The new regression model, created for the Turkish children by using both developing teeth and hand-wrist bones, was considerably successful in estimating the chronological age.

Medico-legal indicators and cut-offs in different age classes through quantitative analysis of epiphyseal fusion segments on knee CT scans.

Scientists are interested in determining age in subadults for several forensic purposes. High- resolution instrumental techniques are being increasingly used for age estimation, driven by the need to minimize errors; in this context, several studies have focused on the knee joint, recognized as a potential site for age examination in late adolescence. We analyzed 200 CT scans performed on Russian subjects (106 males and 94 females) between 13 and 20 years, without growth diseases, endocrine disorders, or osteodystrophy. Each subject underwent two scans, one for each leg. Two indicators were measured for each bone (femur, tibia and fibula): the entire length of the epiphyseal scar and the length of the part/s that is/are fused with metaphysis. Intra class Correlation Coefficient (ICC) was performed to evaluate the intra-operator reproducibility. The ratio between the two lengths was calculated for each bone (FemurR, TibiaR and FibulaR). The first aim was to evaluate a correlation between the ratios of the three bones and the three bones treated as a single parameter (given by the sum of the ratios) versus age. The results showed good correlations in both cases (τ a = 0.74, 0.64, 0.57 and 0.67). The second aim was to estimate the cut-offs derived from the sum of the three ratios respect to four age classes (14-15 years: cut-off ≤ 0.63, 15-16 years: cut-off ≤ 1.19, 16-17 years: cut-off ≥ 0.68 and 17-18 years: cut-off ≥ 1.49. The results from this research encourage further studies of the knee joint as an indicator of legal adult age.

Bone age assessment from articular surface and epiphysis using deep neural networks.

Bone age assessment is of great significance to genetic diagnosis and endocrine diseases. Traditional bone age diagnosis mainly relies on experienced radiologists to examine the regions of interest in hand radiography, but it is time-consuming and may even lead to a vast error between the diagnosis result and the reference. The existing computer-aided methods predict bone age based on general regions of interest but do not explore specific regions of interest in hand radiography. This paper aims to solve such problems by performing bone age prediction on the articular surface and epiphysis from hand radiography using deep convolutional neural networks. The articular surface and epiphysis datasets are established from the Radiological Society of North America (RSNA) pediatric bone age challenge, where the specific feature regions of the articular surface and epiphysis are manually segmented from hand radiography. Five convolutional neural networks, i.e., ResNet50, SENet, DenseNet-121, EfficientNet-b4, and CSPNet, are employed to improve the accuracy and efficiency of bone age diagnosis in clinical applications. Experiments show that the best-performing model can yield a mean absolute error (MAE) of 7.34 months on the proposed articular surface and epiphysis datasets, which is more accurate and fast than the radiologists. The project is available at https://github.com/YameiDeng/BAANet/, and the annotated dataset is also published at https://doi.org/10.5281/zenodo.7947923.

99mTc-MDP bone scintigraphy-based growth evaluation and prediction of epiphysis around the knee: a study of paediatric limb salvage for malignant bone tumours.

AIM: To investigate the feasibility of bone scintigraphy in the assessment and prediction of bone growth potential after limb-salvage surgery in children with bone tumours. MATERIALS AND METHODS: Fifty-five skeletally immature patients with primary bone malignancies in distal femur was enrolled. Thirty-two patients received epiphysis minimally invasive endoprosthesis (EMIE) reconstruction, seven received hemiarthroplasty, and 16 received adult-type rotation-hinged endoprosthesis (ATRHE) reconstruction. All enrolled patients underwent radiographic examination at regular intervals and followed-up for >12 months. The actual limb length discrepancy (LLDa) of the tibia was measured on the radiography image. The expected LLD of tibia (LLDp) was calculated according to multiplier method. The uptake ratio of the ipsilateral epiphysis to the contralateral epiphysis (Ri/c) was calculated at bone scintigraphy. The Ri/c value was accommodated in the formula of multiplier method for a modification. The difference and correlation between the modified expected LLD (LLDm), LLDp and LLDa were analysed. RESULTS: The growth potential of ipsilateral epiphysis was reserved in all patients who underwent hemiarthroplasty and one fourth of EMIE reconstruction. The Ri/c values in the hemiarthroplasty endoprosthesis group were significantly higher than the EMIE and ATRHE groups. There was no significant difference in Ri/c values between the EMIE and ATRHE group. Data from the 26 patients who reached bone maturation showed that there was a significant difference between LLDp and LLDa. LLDm showed a higher correlation with LLDa than LLDp. CONCLUSION: Bone scintigraphy is helpful to evaluate the growth potential of epiphysis after surgery. The multiplier method modified by Ri/c value improves prediction accuracy of bone growth.