The clavicle: normal and abnormal

Extra-Articular Stabilization for the Treatment of Recurrent Sternoclavicular Joint Instability: A Report of Two Cases

CASE

A 22-year-old man and a 14-year-old adolescent boy, who exhibited moderate general joint laxity, experienced recurrent sternoclavicular joint instability without traumatic events. The patients were successfully treated with extra-articular stabilization using autologous tendon grafts without surgical exposure of the sternoclavicular joint.

CONCLUSION

Atraumatic instability of the sternoclavicular joint is rare but often results in recurrent instability accompanied by discomfort, pain, and limitations in activities. Extra-articular stabilization, which reinforces the anterior capsule of the sternoclavicular joint and prevents anterior displacement of the proximal clavicle at the elevated arm position, could be a viable surgical option for this pathological condition.

Incidental osseous lesions on chest CT: an algorithmic approach for radiologists

Numerous osseous findings are commonly discovered incidentally at chest CTs in daily practice. A broad spectrum of these findings ranges from benign and do not touch lesions to ominous conditions requiring further imaging evaluation and/or intervention. Interpretation of these incidental musculoskeletal findings may constitute a diagnostic challenge to radiologists. This review provides a systematic, algorithmic approach to common osseous lesions on chest CT based on imaging findings with recommendations for proper next step management.

Clavicular Malignancies: A Borderline Surgical Management

Nearly 1% of all bone cancers are primary clavicular tumors and because of their rarity, treating clinicians are unfamiliar with their diagnosis, classification, treatment options, and prognosis. In terms of preserving function and avoiding complications, clavicle reconstruction seems logical; however, further studies are needed to support this measure. Reconstruction techniques are difficult taking into account the anatomical structures surrounding the clavicle. When chest wall defects are present, a multidisciplinary team, including an orthopedist and thoracic and plastic surgeons, is of paramount importance for optimal surgical management. Malignant clavicle tumors may include primary and secondary malignancies and neighboring tumors with clavicular invasion. Surgical resection of complex thoracic tumors invading the clavicles can result in larger defects, requiring chest wall reconstruction, which is a substantial challenge for surgeons. Correct diagnosis with proper preoperative planning is essential for limiting complications. Post-resection reconstruction of the partial or total claviculectomy is important for several reasons, including maintaining the biomechanics of the scapular girdle, protecting the vessels and nerves, reducing pain, and maintaining the anatomical appearance of the shoulder. The chest wall resection and reconstruction techniques can involve either partial or full chest wall thickness, influencing the choice of reconstructive technique and materials. In the present paper, we aimed to synthesize the anatomical and physiopathological aspects and the small number of therapeutic surgical options that are currently available for these patients.

Surgical Management of Congenital Pseudoarthrosis of the Clavicle: A Review of Current Concepts

Nowadays, surgical intervention is an accepted treatment for congenital pseudoarthrosis of the clavicle (CPC). The purpose of this literature review is to evaluate the current body of evidence for methods and outcomes of surgical intervention for CPC. CPC is a rare deformity of the middle third of the clavicle not often identified until three to five years of age, at which time surgery is often recommended. The most common indication for surgery is cosmetic appearance, but other indications include pain, shoulder dysfunction, and prevention of complications later in life. Surgical intervention involves the resection and excision of the pseudoarthrosis, bone grafting (most commonly autologous tissue from the iliac crest), and internal fixation using plates or Kirschner wires (K-wires). Plate fixation tends to have fewer complications and better long-term outcomes. Following surgery, outcomes include satisfaction with cosmetic appearance, decreased pain, and improved shoulder function.

The Many Faces of Pediatric Chronic Recurrent Multifocal Osteomyelitis (CRMO): A Practical Location- and Case-Based Approach to Differentiate CRMO From Its Mimics

Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease of childhood and adolescence characterized by episodic bone pain. Diagnosis relies heavily on whole-body MRI and is made by excluding a wide variety of other disorders with overlapping imaging features, depending on location, marrow distribution, and the presence or absence of multifocality. We present an overview of the clinical and imaging features of CRMO and, through various clinical scenarios, provide tips for tailoring the differential diagnosis based on location and distribution of encountered abnormalities. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 3.

RUNX2-modifying enzymes: therapeutic targets for bone diseases

RUNX2 is a master transcription factor of osteoblast differentiation. RUNX2 expression in the bone and osteogenic front of a suture is crucial for cranial suture closure and membranous bone morphogenesis. In this manner, the regulation of RUNX2 is precisely controlled by multiple posttranslational modifications (PTMs) mediated by the stepwise recruitment of multiple enzymes. Genetic defects in RUNX2 itself or in its PTM regulatory pathways result in craniofacial malformations. Haploinsufficiency in RUNX2 causes cleidocranial dysplasia (CCD), which is characterized by open fontanelle and hypoplastic clavicles. In contrast, gain-of-function mutations in FGFRs, which are known upstream stimulating signals of RUNX2 activity, cause craniosynostosis (CS) characterized by premature suture obliteration. The identification of these PTM cascades could suggest suitable drug targets for RUNX2 regulation. In this review, we will focus on the mechanism of RUNX2 regulation mediated by PTMs, such as phosphorylation, prolyl isomerization, acetylation, and ubiquitination, and we will summarize the therapeutics associated with each PTM enzyme for the treatment of congenital cranial suture anomalies.

Morphometric analyses of clavicle's nutrient foramen

PURPOSE

Fractures of the clavicle, which has an important location and function in the upper extremity and shoulder joint, compose 10% of all fracture cases. During the osteosynthesis of clavicle fractures and in the post-operative period of patients, considering the detailed morphometric and topographic properties of the nutrient foramen of clavicle is important to avoid the disruption of arterial nutrition of the clavicle and prevent unexpected injuries. The aim of this study was to investigate the morphometric properties of the nutrient foramen of clavicle in more detail using computedtomography images.

METHODS

Computed tomography images of 116 healthy individuals (56 women/60 men) who had no pathology history were included in the presented study. Computed tomography images were reconstructed three-dimensionally using free-licensed Horos v3.3.3 software. Then, distances from clavicle's nutrient foramen to sternal end, anterior and posterior edges of the clavicle were measured. Statistical analyses were completed using SPSS v21 software.

RESULTS

Our results demonstrated that the nutrient foramen of clavicle was located closer to the sternal end of the clavicle. The shortest distance to the sternal edge of clavicle was measured as 3.3 cm. Analyses of gender differences indicated that statistically significant differences were in favor of men. However, topographic properties of the clavicle's nutrient foramen were not affected by age.

CONCLUSION

Nutrient foramen is mostly located closer to the sternal end of clavicle. Especially during osteosynthesis of clavicle fractures at the sternal end, maintaining the arterial supply of clavicle is of great importance for increasing the post-operative life quality of patients.

Anatomic shape variants of extremitas sternalis claviculae as collected from sternoclavicular thin-slice CT-studies of 2820 male borderline-adults

Within medical age assessment practice, the indicator "medial clavicular ossification" constitutes crucial evidence capable of excluding age minority "beyond reasonable doubt" concerning age-disputed individuals doubtfully claiming children's rights during legal procedures. Yet, one of its characteristics affects the morphological variability including a fair amount of downright peculiar appearances. As a result, inexperienced examiners are tempted to classify actually not-assessable formations according to the two established developmental typologies of Schmeling et al. and Kellinghaus et al. being at the same time the most frequent systemic error of age-related clavicular taxation. Since a respective overview appears missing, the study extracts not-assessable shape variants of the medial collar bone from a large sample of 2820 male borderline-adults as seen from thin-slice, sternoclavicular computed tomography. The two already highlighted configurations "more than one, medial, secondary ossification centres" and "medial metaphyseal concavity" are found as the most commonly encountered features impeding reliable delineation of staging criteria. In accordance with previous literature, it is emphasized that "qualified" rating of extremitas sternalis claviculae within age assessment practice presupposes "knowledge about the diversity of [its] anatomic shape variants."

Temporary Sternoclavicular Stabilization Using an Innovative Blocking Technique with Kirschner Wires for the Treatment of Posterior Sternoclavicular Joint Injury in Adolescent Patients: A Report of Two Cases

CASE

A 15-year-old boy with a posterior physeal fracture-dislocation of the medial aspect of the clavicle and a 14-year-old boy with a posterior sternoclavicular joint dislocation were successfully treated with temporary sternoclavicular stabilization using an innovative blocking technique with Kirschner wires.

CONCLUSION

When treating posterior sternoclavicular joint injuries, posterior instability should be securely stabilized. Temporary blocking stabilization of the sternoclavicular joint using Kirschner wires does not rigidly fix the sternoclavicular joint, but it prevents posterior displacement of the proximal aspect of the clavicle. This stabilizing technique is a simple, safe, and viable treatment option for adolescent patients with a posterior sternoclavicular joint injury.

CT evaluation of medial clavicular epiphysis as a method of bone age determination in adolescents and young adults

PURPOSE

We aimed to investigate the use of computed tomography (CT) staging of the medial clavicular epiphysis ossification in forensic bone age determination, and find a CT criterion to determine whether an individual is adult or not.

METHODS

Chest CT and pulmonary CT angiography exams of 354 patients between 10 and 30 years of age (mean, 21.4 years) were retrospectively evaluated for epiphyseal ossification phase of the bilateral medial clavicles (708 clavicles) and compared with the sex and chronologic age of the individuals. The ossification phase of the medial clavicular epiphyses was classified from stage I to stage V using a modified staging system.

RESULTS

Epiphyseal ossification center appeared from 11 to 21 years of age. Partial fusion occurred between 16 and 23 years of age. Complete fusion was first achieved at the ages of 18 and 19 years for male and female individuals, respectively. The probability of an individual being ≥18 years old was 70.8% in stage III A and 100% in stages III B, IV, and V in females and males.

CONCLUSION

CT evaluation of the medial clavicular epiphysis is helpful in forensic age determination and stage III B can be used as a criterion to make the prediction that an individual is older than 18 years.

An HDAC Inhibitor, Entinostat/MS-275, Partially Prevents Delayed Cranial Suture Closure in Heterozygous Runx2 Null Mice

Cleidocranial dysplasia (CCD) is an autosomal dominant skeletal disorder caused by mutations in RUNX2, coding a key transcription factor of early osteogenesis. CCD patients suffer from developmental defects in cranial bones. Despite numerous investigations and clinical approaches, no therapeutic strategy has been suggested to prevent CCD. Here, we show that fetal administration of Entinostat/MS-275, a class I histone deacetylase (HDAC)-specific inhibitor, partially prevents delayed closure of cranial sutures in Runx2^+/- mice strain of C57BL/6J by two mechanisms: 1) posttranslational acetylation of Runx2 protein, which stabilized the protein and activated its transcriptional activity; and 2) epigenetic regulation of Runx2 and other bone marker genes. Moreover, we show that MS-275 stimulates osteoblast proliferation effectively both in vivo and in vitro, suggesting that delayed skeletal development in CCD is closely related to the decreased number of progenitor cells as well as the delayed osteogenic differentiation. These findings provide the potential benefits of the therapeutic strategy using MS-275 to prevent CCD. © 2017 American Society for Bone and Mineral Research.

Pediatric musculoskeletal injuries: role of ultrasound and magnetic resonance imaging

Pediatric musculoskeletal system is particularly prone to traumatic and sports-related injuries, both acute and chronic, i.e., overuse injuries, because of inherent conditions of weakness, such as the open physis, representing the weakest aspect within the bone, the ligamentous supports and changing biomechanics. Being aware that a quick diagnosis is essential to preserve the good functionality of the limb involved, it is mandatory for the radiologist to recognize the most common patterns of these injuries, identifying those requiring a prompt surgery, as well as be confident with the technique performed, and be supported by an important background experience and knowledge skills.

Midshaft Clavicle Fractures: A Critical Review

The clavicle is the most commonly broken bone in the human body, accounting for up to 5% to 10% of all fractures seen in hospital emergency admissions. Fractures of the middle third, or midshaft, are the most common, accounting for up to 80% of all clavicle fractures. Traditional treatment of midshaft clavicle fractures is usually nonoperative management, using a sling or figure-of-eight bandage. The majority of adults treated nonoperatively for midshaft clavicle fractures will heal completely. However, newer studies have shown that malunion, pain, and deformity rates may be higher than previously reported with traditional management. Recent evidence demonstrates that operative treatment of midshaft clavicle fractures can result in better functional results and patient satisfaction than nonoperative treatment in patients meeting certain criteria. This article provides a review of relevant anatomy, classification systems, and injury mechanisms for midshaft clavicle fractures, as well as a comparison of various treatment options. [Orthopedics.2016; 39(5):e814-e821.].

Morphometric study of the two fused primary ossification centers of the clavicle in the human fetus

Purposes

A satisfactory understanding of the clavicle development may be contributing to both the diagnosis of its congenital defects and prevention of perinatal damage to the shoulder girdle. This study was carried out to examine the transverse and sagittal diameters, cross-sectional area and volume of the two fused primary ossification centers of the clavicle.

Methods

Using the methods of CT, digital-image analysis and statistics, the size for two fused primary ossification centers of the clavicle in 42 spontaneously aborted human fetuses at ages of 18–30 weeks was studied.

Results

Without any male–female and right-left significant differences, the best fit growth models for two fused primary ossification centers of the clavicle were as follows: y = −31.373 + 15.243 × ln(age) ± 1.424 (R² = 0.74) for transverse diameter, y = −7.945 + 3.225 × ln(age) ± 0.262 (R² = 0.78), y = −4.503 + 2.007 × ln(age) ± 0.218 (R² = 0.68), and y = −4.860 + 2.117 × ln(age) ± 0.200 (R² = 0.73) for sagittal diameters of the lateral, middle and medial ends respectively, y = −31.390 + 2.432 × age ± 4.599 (R² = 0.78) for cross-sectional area, and y = 28.161 + 0.00017 × (age)⁴ ± 15.357 (R² = 0.83) for volume.

Conclusions

With no sex and laterality differences, the fused primary ossification centers of the clavicle grow logarithmically in both transverse and sagittal diameters, linearly in cross-sectional area, and fourth-degree polynomially in volume. Our normative quantitative findings may be conducive in monitoring normal fetal growth and screening for inherited faults and anomalies of the clavicle in European human fetuses.

CONGENITAL PSEUDARTHROSIS OF THE CLAVICLE

Congenital pseudarthrosis of the clavicle (PCC) is a rare affection, that can be diagnosed at birth and represent a disturbance of union of the ossification centers. It's more common in girls and in the right side. This study objectives to proceed a revision about the subject, that was searched in online database of LILACS and MEDLINE. We found 56 articles till present data. Besides be a bit infrequent, the PCC must not be missed or even forgotten, especially as differential diagnosis with acute fracture of the clavicle at birth by trauma in the childbirth. The diagnostic is relatively easy and the treatment can be just observation or even surgical.

Forensic age estimation from the clavicle using 1.0T MRI--preliminary results

OBJECTIVES

As forensic age estimations in the living are performed without medical indication, there is a need for the development of non-ionizing methods. This study investigates the use of 1.0T MRI to visualize the ossification status of the medial end of the clavicle.

MATERIAL AND METHODS

T2 weighted 3D images were collected from a 1.0T MR system. We prospectively scanned 102 subjects, 47 autopsy cases and 55 living volunteers (12-33 years). Images were scored in blind trials by three observers using a 4-stage system. Observers differed by level of training and radiological expertise.

RESULTS

Motion artefacts reduced image resolution in living subjects. However, mean age at stage 4 was significantly different from mean age at stage 2 and 3. The minimum age at stage 4 was 19.8 years. Inter-observer agreement was moderate for autopsy cases and slight for living subjects. By contrasting subjects of "incomplete fusion" (≤ stage 3 on both sides) against "fused" (at least one stage 4), agreement rate rose to moderate (K=0.414) for living subjects. Despite the low agreement rate, no subject younger than 18 years was assessed as having "fused" clavicles.

CONCLUSION

At lower image resolution, a 2-stage system increases agreements rates among observers. To further increase accuracy, clavicle staging needs to be performed by trained observers. If available, a 1.0T MR system may be used for age estimation in the living. However, further studies are needed to ensure that the ability to discriminate adults from minors, i.e. 18 years, is maintained.

Unilateral duplication of the acromioclavicular joint: case report and literature review

Clavicle duplication is a rare anatomical variation of the scapular belt: only seven cases have been reported in the literature to date, and only one took note of the existence of a duplication of the acromioclavicular joint. Two hypotheses have been proposed to interpret this variation: genetic factors, or trauma occurred in the growth period. Clavicle duplication should not be mistaken for a quite frequent coracoclavicular joint widely described. The authors report the case of a left acromioclavicular joint duplication in a 51-year-old male patient presenting with left shoulder pain. This case was the first of literature providing 3D CT-scan images.

Primary malignant clavicular tumours: a clinicopathological analysis of six cases and evaluation of surgical management

Primary malignant tumours of the clavicle are extremely rare and little is known regarding their clinicopathological characteristics and outcomes of surgical management. The aim of the study is to analyse the clinical, imaging, and histological features of six patients with malignant tumours of the clavicle and present the outcome of cleidectomy in four of them. A review of the literature is also provided. Six cases were included in this series: two plasmocytomas; three PNETs, one non-Hodgkin lymphoma, one high-grade chondrosarcoma and one post-irradiation fibrosarcoma. Apart from one patient with plasmocytoma and another one with non-Hodgkin lymphoma, the remaining four patients underwent partial or complete cleidectomy according to tumour location. At the time of latest follow-up all patients were alive. Neither local recurrence nor metastases were observed in patients that underwent cleidectomy. In this group, the average score was 86.6% of the expected normal function according to the Musculoskeletal Tumour Society (MSTS) evaluation form. The mean Constant-Murley score of the affected side was 80. Patients after cleidectomy were pain free, they had almost full shoulder range of motion and no significant functional deficit was reported. Primary malignant clavicular tumours may be easily undiagnosed due to their insidious clinical onset. Partial or total cleidectomy is associated with adequate shoulder mobility and mild functional deficit. Therefore, the extent of clavicle excision during tumour removal does not seem to determine the functional outcome of the affected shoulder.

Unveiling the 'unique bone': a study of the distribution of focal clavicular lesions

AIM

Clavicle is a unique bone for many reasons. There is no study discussing the differential diagnosis of clavicular lesions based on the site of occurrence or age at presentation. This study aims to determine whether the distribution of lesions affecting the clavicle and age at presentation aid in the differential diagnosis of focal clavicular lesions.

MATERIALS AND METHODS

Clinical notes, imaging and histopathological reports of the clavicular lesions between Jan 1999 and Jan 2006 were reviewed. Virtually, all patients had been referred as suspected neoplasm.

RESULTS

Fifty-nine patients were identified. Patients <20 years (n = 27) had non-neoplastic or benign lesions. Patients between 20-50 years (n = 14) had predominantly non-neoplastic lesions. Patients >50 years (n = 18) had predominantly malignant lesions. The lesions most commonly affected the medial third (n = 35) and were predominantly non-neoplastic or benign. The middle third was affected in 15 patients and showed both benign and malignant lesions. The lateral third was least affected with predominance of malignant lesions.

CONCLUSIONS

The clavicle is not a primary common site for any particular tumour; hence, diagnosis of the lesions can be challenging. Our study has suggested that few factors like age and site of the lesions may be helpful in diagnosis.

Case report 804: Chondroblastic osteosarcoma grade 3 of the left clavicle

The summary, the case of a 15-year-old boy with osteosarcoma of the clavicle is presented, prompted by the rarity of primary tumors at that site and by this particular tumor's unusual roentgenographic appearance, which suggested a benign process. A review of the literature on clavicular tumors and malignancies is provided. Though extremely rare, primary tumors of the clavicle are more likely to be malignant than benign. This suggests tht serious consideration should be given to malignancy in the face of an apparently aggressive lesion of the clavicle, and perhaps even a benign-appearing tumor as well.