Ossification Of Cartilage Research Articles

A Rare Case of Petrified Ear

Calcification or ossification of the auricle, also referred to as petrified ear, is a rare diagnosis in dermatology. In medical literature, it has most often been attributed to trauma, hypothermia and frostbite, or hypercalcemia secondary to a metabolic or endocrine disorder, such as Addison's disease. Here, we report the clinical and radiologic findings of a 79-year-old African American male whose unilateral petrified auricle was an incidental finding. He had a preceding history of hyperparathyroidism and subsequent hypercalcemia treated with a subtotal parathyroidectomy three years prior to presentation. In addition to laboratory analysis, a history and physical examination was performed which revealed no other signs of hypercalcemia. Radiologic studies demonstrated partial ossification of the external auricular cartilage on the left side. The patient was diagnosed with the rare occurrence of a petrified ear. In light of this case, we provide a discussion concerning the possible etiologies of this diagnosis including appropriate patient evaluation and possible treatment recommendations.

Evaluation and Management of Osteochondral Lesions of the Knee

Osteochondral lesions of the knee is a common disorder in adolescents, although it may present in children and adults. Despite the fact that the disorder was discovered more than a century ago, no specific causes have been identified, although relationships with ischemia, irregular ossification of epiphyseal cartilage, genetic influences, trauma, and endocrine disorders have been postulated. Taking a thorough history and performing a thorough physical examination will facilitate diagnosis of this condition. Radiographic and magnetic resonance imaging are useful diagnostic tools that aid in the evaluation. A comprehensive knowledge of the relevant anatomy and clinical progression of osteochondral lesions allows for a better understanding of the classification systems and, ultimately management of this disorder. The size, location, and stability of the lesion, as well as the patient's age, are crucial in determining optimal treatment. The spectrum of injury ranges from small, stable lesions, which can be treated nonoperatively, to unstable or displaced lesions, which may require surgical management. Surgical options include drilling of subchondral bone, curettage and microfracture, refixation of detached lesions, autologous osteochondral autograft procedures (eg, mosaicplasty, osteochondral autograft transfer system), autologous chondrocyte implantation, and osteochondral allograft resurfacing. This article provides a basic approach to the evaluation and management of osteochondral lesions, as well as indications for surgery.

Changes in the Chondrocyte and Extracellular Matrix Proteome during Post-natal Mouse Cartilage Development

Skeletal growth by endochondral ossification involves tightly coordinated chondrocyte differentiation that creates reserve, proliferating, prehypertrophic, and hypertrophic cartilage zones in the growth plate. Many human skeletal disorders result from mutations in cartilage extracellular matrix (ECM) components that compromise both ECM architecture and chondrocyte function. Understanding normal cartilage development, composition, and structure is therefore vital to unravel these disease mechanisms. To study this intricate process in vivo by proteomics, we analyzed mouse femoral head cartilage at developmental stages enriched in either immature chondrocytes or maturing/hypertrophic chondrocytes (post-natal days 3 and 21, respectively). Using LTQ-Orbitrap tandem mass spectrometry, we identified 703 cartilage proteins. Differentially abundant proteins (q < 0.01) included prototypic markers for both early and late chondrocyte differentiation (epiphycan and collagen X, respectively) and novel ECM and cell adhesion proteins with no previously described roles in cartilage development (tenascin X, vitrin, Urb, emilin-1, and the sushi repeat-containing proteins SRPX and SRPX2). Meta-analysis of cartilage development in vivo and an in vitro chondrocyte culture model (Wilson, R., Diseberg, A. F., Gordon, L., Zivkovic, S., Tatarczuch, L., Mackie, E. J., Gorman, J. J., and Bateman, J. F. (2010) Comprehensive profiling of cartilage extracellular matrix formation and maturation using sequential extraction and label-free quantitative proteomics. Mol. Cell. Proteomics 9, 1296-1313) identified components involved in both systems, such as Urb, and components with specific roles in vivo, including vitrin and CILP-2 (cartilage intermediate layer protein-2). Immunolocalization of Urb, vitrin, and CILP-2 indicated specific roles at different maturation stages. In addition to ECM-related changes, we provide the first biochemical evidence of changing endoplasmic reticulum function during cartilage development. Although the multifunctional chaperone BiP was not differentially expressed, enzymes and chaperones required specifically for collagen biosynthesis, such as the prolyl 3-hydroxylase 1, cartilage-associated protein, and peptidyl prolyl cis-trans isomerase B complex, were down-regulated during maturation. Conversely, the lumenal proteins calumenin, reticulocalbin-1, and reticulocalbin-2 were significantly increased, signifying a shift toward calcium binding functions. This first proteomic analysis of cartilage development in vivo reveals the breadth of protein expression changes during chondrocyte maturation and ECM remodeling in the mouse femoral head.

A case of ossified laryngeal cartilage mimicking a subglottic mass

A previously healthy 54-year-old man complained of progressive voice changes. A firm subglottic polypoid mass was located at the right posterior site, as seen on fiberoptic laryngoscopy, with a distinctly narrowed subglottic space being seen on neck computed tomography, and there were multiple opacities from the cricoid cartilage to the tracheal rings. Resection was done under general anesthesia. The mass-like elevated lesion showed enchondral ossification of the laryngeal cartilage just beneath the squamous metaplastic surface epithelium. The vocal cord mobility was normal. Compared with the computed tomography and the laryngoscopic examination, the polypoid mass-like elevation corresponded to a ossified vocal process of the right arytenoid cartilage. To date, clinically symptomatic ossification of the laryngeal cartilages has presented with foreign body–like impaction. The present case is a rare case of ossification of the laryngeal cartilage that masqueraded as a subglottic polypoid mass. The ossification of laryngeal cartilage is part of the normal aging process, but a tumor-like mass at the airway related with voice changes, like was seen in the present case, is rare. Albeit rare, clinicians and radiologists should be aware that this heterotopic ossification may mimic a polypoid mass–like presentation as well as the accompanying symptoms.

New case of Primrose syndrome with mild intellectual disability

We report on a 27-year-old man, who represents the sixth and the youngest published case of Primrose syndrome. Primrose syndrome (PS) (OMIM#295090) is an extremely rare entity of unknown etiology characterized by the progressive wasting of distal muscles of the legs, the small muscles of the hands resulting in contractures, the presence of intellectual disability, hearing problems, cataracts, brain calcification, and the ossification of ear cartilage. All the main manifestations were present in our patient. Despite the phenotypic similarity to five other cases, our patient had mild intellectual disability. Additionally we found hypergonadotropic hypogonadism and a low bone density due to progressive osteoporosis. We discuss our observations in relation to previously published cases, and we stress the need for the detail and phenotypic descriptions of further cases as PS remains rare, and the genetic basis is still undiscovered.

Idiopathic Acquired Ectopic Auricular Ossification: A Case Report and Review of the Literature

A petrified auricle is a rare condition in which the structure becomes partially or completely rigid. It arises as a consequence of calcification or ossification of the auricular cartilage. An ossified auricle is much more rare than a calcified cartilage, and it can be diagnosed only by histology. To the best of our knowledge, only 18 cases of ossification of the auricle have been previously reported in the literature. We report a new case of auricular ossification in a 72-year-old woman who had taken calcium for the previous 8 years. We also review the relevant literature.

Injuries associated with the cartilages of the foot

SummaryThere is a growing body of evidence that uniaxial or biaxial ossification of the cartilages of the foot should not be discounted as irrelevant in a lame horse, especially if extensive. Potential causes of pain and lameness include primary injury of an ossified cartilage and/or the ipsilateral aspect of the distal phalanx, injury of the chondrocoronal or chondrosesamoidean ligaments and desmopathy of the collateral ligaments of the distal interphalangeal joint.

Experimental study of cartilage lesions and COLIXA 3 protein expression in rats cartilage with chronic fluorosis

Objective To explore whether different degrees of fluorosis influence the expression of cartilage COLIXA3 protein in fluorosis model rats. Methods Forty male Wistar rats 3 to 4 weeks old were randomly divided into 5 groups according to body mass, and these rats were fed with distilled water containing sodium fluoride(NaF) of 0(control), 25, 50, 100 and 150 mg/L for 6 months, respectively, in order to establish the animal model of drinking water type fluorosis. Pathomorphologieal changes of the osseous tissues of rats were analyzed under light microscope and transmission electron microscope, and the expression of COLIXA3 protein of femur metaphysis was examined by immunohistochemistry. Results HE staining showed different degrees of femoral metaphyseal ossification of cartilage in each experimental group, bone density increased, with sclerotic lesions of skeletal fluorosis. The control group showed no abnormal cartilage. Electron microscopy showed that the experimental groups with varying degrees of cartilage cell swelling, cell matrix fades, 50 mg/L group .showed hyperplasia, and 100,150 mg/L groups were observed with organelles decreased, part of the disintegration of the cartilage cell lacunae, lmmunohistochemical staining of rat chondrocytes COLIXA3 was positive, cytoplasm with brown granules, cartilage COLIXA3 protein expression(23.3 ± 4.5, 41.2 ± 5.6, 26.4 ~ 7.5) in the 25, 50 and 100 mg/L groups enhanced. Compared to the control group (6.1 ± 3.5), the expression of 50 and 100 mg/L groups was significantly increased, and the differences were statistically significant(all P 0.05). Conclusions There has pathological changes of sclerosing skeletal fluorosis in animal model. Low-dose fluoride promotes while high-dose inhibits cartilage cell proliferation. When fluorine concentration in external environment is too high and with extended exposure to fluoride, direct toxic effects of fluoride on cartilage cells is observed. Fluorine affects and promotes the expression of COLIXA3 protein in cartilage. Low-dose fluoride can promote COLIXA3 protein expression, as the dose increases (over 100 mg/L), the effect decreases. Key words: Fluorosis, dental; Cartilage; COLIXA3 gene ; Rat

Loss of transcription factor early growth response gene 1 results in impaired endochondral bone repair

Transcription factors that play a role in ossification during development are expected to participate in postnatal fracture repair since the endochondral bone formation that occurs in embryos is recapitulated during fracture repair. However, inherent differences exist between bone development and fracture repair, including a sudden disruption of tissue integrity followed by an inflammatory response. This raises the possibility that repair-specific transcription factors participate in bone healing. Here, we assessed the consequence of loss of early growth response gene 1 (EGR-1) on endochondral bone healing because this transcription factor has been shown to modulate repair in vascularized tissues. Model fractures were created in ribs of wild type (wt) and EGR-1(-/-) mice. Differences in tissue morphology and composition between these two animal groups were followed over 28 post fracture days (PFDs). In wt mice, bone healing occurred in healing phases characteristic of endochondral bone repair. A similar healing sequence was observed in EGR-1(-/-) mice but was impaired by alterations. A persistent accumulation of fibrin between the disconnected bones was observed on PFD7 and remained pronounced in the callus on PFD14. Additionally, the PFD14 callus was abnormally enlarged and showed increased deposition of mineralized tissue. Cartilage ossification in the callus was associated with hyper-vascularity and -proliferation. Moreover, cell deposits located in proximity to the callus within skeletal muscle were detected on PFD14. Despite these impairments, repair in EGR-1(-/-) callus advanced on PFD28, suggesting EGR-1 is not essential for healing. Together, this study provides genetic evidence that EGR-1 is a pleiotropic regulator of endochondral fracture repair.

FRACTURES OF THE DISTAL PHALANX AND ASSOCIATED SOFT TISSUE AND OSSEOUS ABNORMALITIES IN 22 HORSES WITH OSSIFIED SCLEROTIC UNGUAL CARTILAGES DIAGNOSED WITH MAGNETIC RESONANCE IMAGING

Ungual cartilage ossification in the forelimb is a common finding in horses. Subtle abnormalities associated with the ungual cartilages can be difficult to identify on radiographs. Magnetic resonance (MR) imaging findings of 22 horses (23 forelimbs) with a fracture of the distal phalanx and ossified ungual cartilage were characterized and graded. All horses had a forelimb fracture. Eleven involved a left forelimb (seven medial; four lateral), and 12 involved a right forelimb (five medial; seven lateral). All fractures were nonarticular, simple in configuration, and nondisplaced. The fractures were oriented in an axial proximal to abaxial distal and palmar to dorsal direction, and extended from the base of the ossified ungual cartilage into the distal phalanx. The fracture involved the fossa of the collateral ligament on the distal phalanx in 17 of 23 limbs. The palmar process and ossified ungual cartilage was abnormally mineralized in all horses. Ligaments and soft tissues adjacent to the ossified ungual cartilages were affected in all horses. The routine site of fracture in this study at the base of the ossified ungual cartilage extending into the distal phalanx suggests a biomechanical cause or focal stress point from cycling. The ligamentous structures associated with the ungual cartilages were often affected, showed altered signal intensity as well as enlargement and were thought to be contributing to the lameness. In conclusion, ossified ungual cartilages may lead to fracture of the palmar process of the distal phalanx and injury of the ungual cartilage ligaments.

Thyroid Alar Cartilage Graft Laryngotracheal Reconstruction in Adults

To assess the outcomes of laryngotracheal reconstruction using thyroid alar cartilage grafting in adult patients with laryngotracheal stenosis. Case series with chart review. Tertiary university hospital. Twelve adults who underwent thyroid alar cartilage graft laryngotracheal reconstruction from April 1997 to April 2009 for laryngotracheal stenosis were analyzed. The mean age of the study population was 29 years. Using the Myer-Cotton grading system, 3 patients had grade II stenosis, 7 had grade III, and 2 had grade IV. Seven of the 12 patients had subglottic stenosis, 3 had tracheal stenosis, and 2 had subglottic and upper tracheal stenosis. Nine of 12 (75%) patients were decannulated. Of the patients in whom laryngotracheal reconstruction failed, 2 had grade IV stenosis and 1 had severe grade III stenosis with a long segment of stenotic tissue. The postoperative complications were hematoma of the left laryngeal ventricle at the donor site in 1 patient, granulation tissues in the supraglottic and suprastomal region and at the graft site in 4 patients, and neck wound infection in 1 patient. Ossification of the thyroid alar cartilage was observed in 2 patients. A Ttube remained in situ for 6 to 18 months. Laryngotracheal reconstruction with thyroid alar cartilage graft could be a viable alternative for the treatment of laryngotracheal stenosis in adults. However, it should be used only in cases of limited and minor subglottic or tracheal stenosis.

Venous drainage from the developing human base of mandible including Meckel’s cartilage: the so-called Serres’ vein revisited

The present study describes the venous drainage, especially, that via the so-called Serres' vein, from border areas between two different types of ossifications: the endochondral ossification of Meckel's cartilage in close topographical relation with the membranous ossification of the mandible. Frontal and transverse sections of 25 human fetuses between 8 and 16weeks of post-conception development. All sections were stained with hematoxylin, and eosin and azan. At 9weeks, a distinct vein (Serres' vein) is seen originating from the endochondral ossification of Meckel's cartilage. At 11weeks, the vein collects blood sinusoids from both the endochondral and membranous ossification areas. At 12weeks the vein accompanies a definite bony canal, the Serres' canal. The vein does not extend anteriorly beyond a level of the deciduous canine germ that was located anterior to the mental foramen. Notably, up to 12weeks, the vein becomes clearly isolated from the inferior alveolar nerve, artery, and vein. Serres' vein seems to be a unique drainage route of ossification, not of the tooth germ, and is similar to veins at the usual diaphysis of a long bone. Although the Serres' canal had been termed "canal of the deciduous dentition", there appears to be no topographical relation with deciduous germs.

The effect of year and season of birth, sex, sire, and breeder on ossification of the distal epiphyseal cartilage of the radial bone in Thoroughbred horses

The aim of this study was to evaluate the effect of specific factors on ossification of the distal epiphyseal cartilage of the radial bone in Thoroughbred horses. The study was carried out on 452 Thoroughbred horses, two years old, that were under race training. X-ray tests were conducted and interpreted every month starting at the 18th month of life and continuing until ossification of the distal epiphyseal cartilage of the radial bone occurred. In the statistical model, the year of birth, sex, birth season, sire, and breeder were treated as constant effects. Horses that were born in the spring season were characterized by a shorter time until the closure of the distal radial epiphyseal cartilage in comparison to horses born in the winter season; the difference between these times was found to be highly significant. Furthermore, it was shown that the ossification time of cartilage was also significantly influenced by the year of birth, the sire, and the breeder. Knowledge and monitoring of factors affecting the rate of somatic maturity in Thoroughbred horses can be useful in breeding and veterinary practices. This fact, in conjunction with the analysis of somatotrophic processes, will provide a basis for improving the feeding, training, and management system of Thoroughbred horses as well as aiding in the early diagnosis, treatment, or prevention of various diseases associated with intensive growth in the early period of life.

Forensic Age Estimation on Digital X‐ray Images: Medial Epiphyses of the Clavicle and First Rib Ossification in Relation to Chronological Age*,†

In recent years, there has been a renewed interest in forensic sciences about forensic age estimation in living subjects by means of radiological methods. This research was conducted on digital thorax X-rays to test the usefulness of some radiological changes in the clavicle and first rib. The sample consisted in a total of 123 subjects of Spanish origin (61 men and 62 women; age range: 5-75 years). From all subjects, a thorax posterior-anterior radiograph was obtained in digital format. Scoring for fusion of medial epiphyses of the clavicle was carried out by Schmeling's system and ossification of the costal cartilage of the first rib by Michelson's system. Degree of ossification and epiphyseal fusion were analyzed in relation with known age and sex of these subjects. The results give a minimum age of >20 years for full fusion of the medial epiphysis of the clavicle (Stages 4 and 5). Concerning the first rib, all subjects with the final Stage 3 of ossification were above 25 years of age. These results suggest that the first rib ossification might become an additional method to the ones so far recommended for forensic age estimation in subjects around 21. New research would be desirable to confirm this suggestion.

Risiko des autogenen Knorpeltransplantats bei laryngotrachealer Rekonstruktion bei Erwachsenen

Laryngotracheal reconstruction with autogenous rib cartilage graft has become a well established surgical method for the repair of subglottic and glottic laryngotracheal stenoses in infants and children. There are far fewer reports on the application of this method in adult patients. In particular, detailed observations of the healing behaviour of autogenous adult rib cartilage grafts are lacking. The course of disease in five adult female patients (age 25-47years) who underwent one- or two-stage laryngotracheal reconstruction with rib cartilage grafts are reported. Primary healing was observed in the youngest patient (25years) only. In the other four patients the cartilage graft had to be partly removed 4-6weeks postoperatively due to partial necrosis, followed by open wound treatment. As a result of these measures a sufficiently large laryngotracheal lumen could be achieved in all cases. Partial ossification of the adult rib cartilage was considered the reason for the observed healing difficulties. Endoscopic follow-up showed that epithelialization of the free endolaryngeal surface of the cartilage graft, i.e. graft healing, takes at least 3months. Therefore, close endoscopic follow-up during this period appears indispensable.

Is there an association between ossification of the cartilages of the foot and collateral desmopathy of the distal interphalangeal joint or distal phalanx injury?

Associations between degree of ossification of the cartilages of the foot and injuries to other structures of the foot have been suggested, but have not been investigated by large scale studies. To describe the frequency of grade >3 ossification of the cartilages of the foot (possibly significant ossification, PSO), mediolateral symmetry of ossification and left-right symmetry between feet; and to investigate associations between PSO and injury of either the collateral ligaments (CLs) of the distal interphalangeal (DIP) joint or the distal phalanx. Possibly significant ossification of the cartilages of the foot is associated with CL and distal phalanx injury. Distal phalanx injury is associated with a mediolateral difference in ossification grade of > or =2. Horses were examined for lameness localised to the foot by perineural analgesia, and underwent radiographic and magnetic resonance imaging examinations. Age, breed, occupation, duration of lameness, lame(st) limb, primary cause of lameness, and presence or absence of CL injury were recorded. Dorsopalmar (dorsoplantar) radiographs were examined and ossification of the cartilages of the foot graded using a modification of a previously published scale. One foot from each of 462 horses was included for analysis. There was left-right symmetry of ossification between feet, and significant association between grades of each foot, with lateral > or =medial cartilages. Possibly significant ossification occurred in the maximally ossified cartilage in 59 (12.8%) feet. There were significant associations between PSO of the maximally ossified cartilage of the foot and injuries of both the CLs of the DIP joint and the distal phalanx. There was no association between distal phalanx injury and marked asymmetry of the ossified cartilages of the foot. Extensively ossified cartilages of the foot are significantly associated with CL or distal phalanx injury. Markedly asymmetric ossification did not increase the likelihood of distal phalanx injury and should be considered at a prepurchase examination.

MOTOR TICS, STEREOTYPIES, AND SELF-FLAGELLATION IN PRIMROSE SYNDROME

Primrose syndrome consists of cognitive and motor delay, characteristic facial dysmorphism with enlarged and calcified external ears, cataracts, hearing impairment, spastic paraparesis with joint contractures, and distal muscle wasting. To our knowledge, only 5 cases have been reported in the literature.1–5 We report the sixth case and only the second woman to fulfill all clinical elements of Primrose syndrome, who, in addition, manifested motor tics, hand stereotypies, and self-flagellating behaviors. This patient remained undiagnosed for over 4 decades. ### Case report. A 43-year-old woman, the product of a normal vaginal delivery and negative neurologic family history, was born with congenital heart disease (Ebstein malformation, mitral valve prolapse), congenital hip dysplasia, and agenesis of the corpus callosum. In early childhood, she was found to have hearing impairment, cataracts, a nondescript neoplasm of the bone in the palate, ossification of cartilage, cystic changes in bones, diabetes mellitus, and hypothyroidism. Walking began at the age of 6 years. The limited repertoire of her language included “mommy,” “daddy,” “bye-bye,” and “go to school,” before she lost vocalization altogether in her late 30s. She attended special education for about 18 years and worked at putting bakery projects together for several years thereafter. She had been able to run and roller skate before her gait deteriorated. She slowly lost the ability to ambulate independently. At age 35, she started using a walker, and by age 40 needed …

Multislice Computed Tomography of the First Rib: A Useful Technique for Bone Age Assessment

Macroscopic study of the first rib has been described by Kunos et al. as an efficient method of age estimation. We retrospectively reviewed a test sample of 160 first right ribs obtained from multislice computed tomography (MSCT) clinical investigations of living individuals aged 15-30 years old. Based on the descriptions of Kunos et al., we analyzed the morphological appearance of the sternal end of the first rib on two- and three-dimensional MSCT reconstructions and defined changes in appearance in stages (from 2 to 5). We also studied the calcification and ossification of the costal cartilage as an independent feature. By statistical analysis (ANOVA), we determined for each gender the correlation between the estimated stage of the costal face, the appearance of the costal cartilage, and the documented age of the subjects. We demonstrated that MSCT of the first rib appears to be an efficient noninvasive modality for bone age estimation.

Metaplastic ossification in the cartilage of the bronchus of a patient with chronic multi-drug resistant tuberculosis: a case report

IntroductionPulmonary ossification has been rarely observed in pulmonary fibrosis and in some chronic respiratory diseases such as chronic obstructive pulmonary disease. We report here a metaplastic ossification in the bronchial cartilage of a patient with multi-drug resistant tuberculosis.Case presentationWe report the case of a 41-year-old Asian man from Korea with chronic multi-drug resistant tuberculosis with a rare focus of bone formation from the cartilage of a bronchus subtending an active cavity. The patient had a large multi-lobed, thick-walled cavitary tuberculosis lesion in his left upper lobe. Severe infiltration of his lymphocytes and epithelioid cells, along with some giant cells and neutrophils, was observed in the patient's bronchial wall. Desquamated bronchial epithelium and acid-fast bacilli were found inside his bronchus. A small focus of bony metaplasia was found in the cartilage of his bronchial wall. Histopathological examination confirmed calcification and showed hematopoietic cells forming in his marrow cavity.ConclusionsChronic inflammation in the lungs of our patient, caused by underlying tuberculosis, probably played a role in the development of osseous metaplasia from the associated cartilage of the bronchial wall.

A Modified Risser Grading System Predicts the Curve Acceleration Phase of Female Adolescent Idiopathic Scoliosis

The Risser sign can be assessed with the United States method or the European method. The Tanner-Whitehouse method estimates skeletal age on the basis of hand radiography and digital skeletal age. Digital skeletal age scores between 400 and 425 are associated with the beginning of the curve acceleration phase or peak growth velocity in adolescent idiopathic scoliosis. The first objective of the present study was to evaluate the agreement between the two Risser grading systems. The second objective was to identify which grading system best predicts a digital skeletal age of between 400 and 425. The third objective was to explore a new system that could be used to replace the Risser method. One hundred female patients with adolescent idiopathic scoliosis were recruited in this cross-sectional descriptive study. Each patient was evaluated with posteroanterior spine and hand radiographs. The Risser sign was measured according to both the United States and European grading systems. Digital skeletal age was calculated, and triradiate cartilage ossification was assessed. With use of kappa statistics, moderate agreement between the United States and European grading systems was seen. Risser stages alone were not good predictors of the curve acceleration phase. A new system with three groups was tested, and the second group (Risser 0 with closed triradiate cartilage and Risser 1) was the best predictor of a digital skeletal age score of between 400 and 425. Two Risser grading systems coexist, and the agreement between them is moderate. No Risser stage was found to be a good clinical landmark for the beginning of the curve acceleration phase of adolescent idiopathic scoliosis. A new group, Risser 0 with closed triradiate cartilage and Risser 1, was the best predictor of the beginning of the curve acceleration phase. This new system is easy to implement and is based on findings that are available on spine radiographs. It should be used at the first visit and for scoliosis follow-up to assess skeletal maturity and correlation with the curve acceleration phase.