Radiographic evaluation of the forelimb bone development in maned wolves (Chrysocyon brachyurus).

This study aimed to assess the fusion of growth plates and the development of secondary ossification centres in the forelimb bones of maned wolves (Chrysocyon brachyurus), contrasting the findings with established data from domestic dogs. Three maned wolves, comprising one male and two females, initially aged between 3 and 4 months, were subjected to monthly radiographic evaluations until 10-11 months of age, followed by bimonthly assessments until 18-19 months of age, encompassing both forelimbs. The closure times of growth plates were observed as follows: supraglenoid tubercle (7-8 months), proximal humerus (17-19 months), distal humerus (8-9 months), medial epicondyle of the humerus (8-9 months), proximal ulna (9-10 months), proximal radius (13-15 months), distal ulna (13-15 months) and distal radius (17-19 months). Statistical analysis revealed significant differences in the areas of secondary ossification centres in the proximal epiphyses of the humerus and radius, respectively, observed from the initial evaluation at 8-9 months and 6-7 months. Conversely, the epiphyses of the supraglenoid tubercle, distal humerus, proximal ulna, distal ulna, medial epicondyle of the humerus and distal radius did not exhibit significant area differences between 3-4 months and 4-5 months, yet notable distinctions emerged at 5-6 months. In summary, while the radiographic appearance of epiphyseal growth plates and secondary ossification centres in maned wolves resembles that of domestic dogs, closure times vary. These findings contribute to understanding the dynamics of epiphyseal growth plates in this species.

Clinical and Functional Outcomes of Ulnar Lengthening in the Treatment of Masada Type I Forearm Deformities in Hereditary Multiple Osteochondromas.

PURPOSE: Forearm deformity is common in hereditary multiple osteochondromas (HMO). The results of ulnar lengthening and osteochondroma excision are generally favorable, both clinically and radiographically. This study aimed to assess the clinical, radiographic, and functional results of forearm reconstruction in patients with Masada type I deformity (osteochondroma in the distal ulna with radial bowing, without radial head dislocation). METHODS: A retrospective review was performed on patients with HMO who underwent surgical reconstruction for a Masada type I forearm deformity over a 10-year period. Eleven forearms in 10 patients underwent gradual ulnar lengthening with an external fixator. Age at the time of surgery was 5 to 12 years. Radiographic evaluation included ulnar shortening, radial articular angle, and carpal slip. Clinical evaluation included range of motion of the elbow and wrist. Functional outcomes were evaluated with the Disabilities of the Arm, Shoulder, and Hand questionnaire and the Short Form-36 survey. RESULTS: At an average follow-up of 37.5 months, significant improvement was observed in ulnar shortening, the radial articular angle, and carpal slip. Preoperative average Disabilities of the Arm, Shoulder, and Hand score of 24.2 improved to 17.3. Significant improvement was observed in 3 measures of the Short Form-36 survey: general health, social functioning, and health change. CONCLUSIONS: In agreement with the literature, surgical reconstruction yielded favorable clinical and radiographic results in Masada type I forearm deformities. The main functional improvement was observed in scales of mental health. The baseline physical impairment was minimal in the absence of radial head dislocation, but although it improved with treatment, it was not necessarily clinically relevant. This study can assist surgeons and families in setting realistic goals and expectations for surgery. There may also be additional long-term benefits to forearm lengthening in HMO, including prevention of radial head dislocation, improved range of motion, and better cosmesis, which future research may help to clarify. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Surgical importance of radiographically aided morphometry of the proximal ulna / Importancia quirúrgica de la morfometría de la ulna proximal con examen radiográfico

This study was conducted to define the proximal ulnar morphometry with respect to dorsal and intramedullary implant design. Eighty two dry Anatolian ulnae were evaluated by both the traditional and digital morphometric analysis methods. Also the medullary cavities and cortical bone thicknesses were measured from radiographic images. The mean value of ulnar length (UL) was 25.06 cm; distance between the most prominent anterior point of the superior surface of the olecranon (MAPO) and the most posterior point of the olecranon (MPPO), distance between the MPPO and maximum anterior angulation (MAA), distance between the MPPO and the maximum varus angulation (MVA) were; 1.67 cm, 5.36 cm and 7.56 cm, respectively. The average antero-posterior diameters at midolecranon plane (MOP), MAA plane (MAAP) and MVA plane (MVAP) were; 1.78 cm, 1.68 cm and 1.41 cm; transverse diameters of same planes were; 1.96 cm, 1.65 cm and 1.51 cm, respectively. The mean olecranon angle (OA), MAA and MVA were: 113.35°, 9.12° and 13.82°; also the mean circumferences at same planes were 6.48 cm, 6.37 cm and 5.16 cm, respectively. The mean antero-posterior medullary diameter at MAAP and mean transverse medullary diameter at MVAP were; 6.83 mm and 7.22 mm, respectively. Mean anterior and posterior cortical bone thicknesses at MAAP were: 3.61 mm and 4.25 mm; the mean medial and lateral cortical bone thicknesses at MVAP were: 4.06 mm and 4.13 mm, respectively. Dorsal angulation and medullary angulation of the proximal ulna presents different architecture. Unique morphological architecture of the proximal ulna should be taken into consideration in means of surgical operations and examination of radiographic images. It can be inferred that standardized bony landmarks may helpful during the process of designing and manufacturing precurved dorsal plates and as well as variable proximal ulnar implants.

Este estudio se realizó para definir la morfometría ulnar proximal con respecto al diseño de implante dorsal e intramedular. Ochenta y dos ulnas de Anatolia secas fueron evaluadas por los métodos de análisis morfométrico tradicional y digital. También se midieron las cavidades medulares y el grosor del hueso cortical a partir de imágenes radiográficas. El valor medio de la longitud ulnar (LU) fue de 25,06 cm; distancia entre el punto anterior más prominente de la superficie superior del olécranon (SSO) y el punto más posterior (PPO), la distancia entre el PPO y la angulación anterior máxima (AAM), la distancia entre el PPO y la angulación máxima en varo (AMV) fueron; 1,67 cm, 5,36 cm y 7,56 cm, respectivamente. Los diámetros anteroposteriores medios en el plano medio del olécranon (PMO), el plano AAM (AAP) y el plano AMV fueron; 1,78 cm, 1,68 cm y 1,41 cm; los diámetros transversales de los mismos planos eran; 1,96 cm, 1,65 cm y 1.51 cm, respectivamente. El ángulo medio del olécranon (AMO), AAM y MVA fueron: 113,35 °, 9,12 ° y 13,82 °; También las circunferencias medias en los mismos planos fueron 6,48 cm, 6,37 cm y 5,16 cm, respectivamente. El diámetro medular anteroposterior medio en AMV y el diámetro medular transversal medio en AMV fueron; 6,83 mm y 7,22 mm, respectivamente. Los grosores óseos corticales anteriores y posteriores medios en AMV fueron: 3,61 mm y 4,25 mm; Los espesores medios de los huesos corticales medial y lateral en AMV fueron: 4,06 mm y 4,13 mm, respectivamente. La angulación dorsal y la angulación medular de la ulna proximal presentan una arquitectura diferente. La arquitectura morfológica única de la ulna proximal debe tenerse en cuenta en las operaciones quirúrgicas con el examen de imágenes radiográficas. Se puede inferir que los puntos de referencia óseos estandarizados pueden ser útiles durante el proceso de diseño y fabricación de placas dorsales precurvadas y también de implantes ulnares proximales variables.

Anatomy, Morphometry and Radiography in the thoracic limb bones of the Patagonian Huemul Deer (Hippocamelus bisulcus).

The aim of this study was to provide morphometric, anatomic and radiographic data of the thoracic limb bones of the Patagonian Huemul (Hippocamelus bisulcus) including a functional interpretation of this, as a reference for clinical use, biomedical research and teaching purposes. Currently, the Patagonian huemul deer is in danger of becoming extinct due to multiple causes. Research carried out for its conservation has focused mainly on its ecology and pathology, leaving gaps in biological knowledge, which is basic and important for its comprehension. This study was conducted to reveal the gross osteology and radiology features of the thoracic limb bones of the Patagonian huemul deer. The osteological findings suggest the presence of powerful flexor muscles in the scapulohumeral and elbow joints, useful to cushion the jumps. Also, the principal nutrient foramen of Patagonian huemul differs in position with respect to domestic ungulates, which may be important to consider during surgical procedures. Finally, the radiographic data can provide new information about the tissue loading conditions in Patagonian huemul, so that this new knowledge can be of great importance for a better understanding of mechanically induced or adaptive changes in bone produced by habitat or other ecological phenomena.

Chronic recurrent multifocal osteomyelitis exhibiting predominance of periosteal reaction.

Chronic recurrent multifocal osteomyelitis is an idiopathic nonpyogenic autoinflammatory bone disorder involving multiple sites, with clinical progression persisting for more than 6 months and which may have episodes of remission and exacerbation in the long term. It represents up to 2-5% of the cases of osteomyelitis, with an approximate incidence of up to 4/1,000,000 individuals, and average age of disease onset estimated between 8-11 years, predominantly in females. The legs are the most affected, with a predilection for metaphyseal regions along the growth plate. We describe the case of a female patient, aged 2 years and 5 months, with involvement of the left ulna, right jaw and left tibia, showing a predominance of periosteal reaction as main finding.

Chronic recurrent multifocal osteomyelitis exhibiting predominance of periosteal reaction / Osteomielite crônica multifocal recorrente exibindo predomínio de reação periosteal

Summary Chronic recurrent multifocal osteomyelitis is an idiopathic nonpyogenic autoinflammatory bone disorder involving multiple sites, with clinical progression persisting for more than 6 months and which may have episodes of remission and exacerbation in the long term. It represents up to 2-5% of the cases of osteomyelitis, with an approximate incidence of up to 4/1,000,000 individuals, and average age of disease onset estimated between 8-11 years, predominantly in females. The legs are the most affected, with a predilection for metaphyseal regions along the growth plate. We describe the case of a female patient, aged 2 years and 5 months, with involvement of the left ulna, right jaw and left tibia, showing a predominance of periosteal reaction as main finding.

Resumo Osteomielite crônica multifocal recorrente é uma desordem autoinflamatória óssea idiopática não piogênica, envolvendo vários sítios e com evolução clínica persistindo por mais de 6 meses, podendo apresentar episódios de remissão e exacerbação em longo prazo. Representa de 2 a 5% das osteomielites, com incidência aproximada de até 4/1.000.000, com idade média de apresentação estimada entre 8 e 11 anos, predominando no gênero feminino. Os membros inferiores são os mais afetados, com predileção para regiões metafisárias junto à fise. Descrevemos um caso da doença em uma menina de 2 anos e 5 meses de idade, com acometimento de ulna esquerda, mandíbula à direita e tíbia esquerda, exibindo predomínio de reação periosteal como achado principal.

Fechamento epifisário do úmero, rádio e ulna da paca (Agouti paca) / Epiphyseal closure of the paca’s humerus, radius and ulna (Agouti paca)

Background: After the capybara, the Agouti paca is the largest rodent in the neotropical region, with a body weight that usually varies from 5 to 10 kg, but may reach up to 14 kg. Pacas reach sexual maturity at around 10 months of age. Recently, this species has been increasingly being subject of studies on tissue morphology, placentation, and experimental surgery. The time at which epiphyseal plates close varies according to each bone; some can close during intrauterine life, while some can persist for many years. The aim of this research was to examine, through radiography, the long bones of the thoracic limbs (humerus, radius, and ulna) of the paca, and correlate their epiphyseal closure times with the animal’s age. Materials, Methods & Results: Eight animals born in captivity were radiographically evaluated monthly from birth until 22 months of age. The animals were kept in stalls made of masonry, with an area of approximately 15 m2 . Each stall had one burrow with three internal interconnected sub-sections. Each stall housed one male and two or three females with microchip implants applied dorsally in the cervical region. The animals were fed rodent chow (1.0% of body weight per day) and fruits of the season (10% of body weight per day), which were offered daily in the afternoon. The animals were radiographed at the Division of Radiology of the Veterinary Hospital of the School of Veterinary Medicine, São Paulo State University, Jaboticabal, SP, Brazil. Craniocaudal and mediolateral views of the humerus, radius, and ulna were performed. Sedation was performed using meperidine (2.5 mg/kg) and diazepam (0.5 mg/kg) in a single intramuscular injection. For anesthesia, ketamine (20 mg/kg) and xylazine (1.5 mg/kg) were administered in leg muscles 10 minutes after sedation. The anesthesia used proved to be efficient for transportation, handling, and positioning of the animals for radiographic exams.[...]

Fechamento epifisário do úmero, rádio e ulna da paca (Agouti paca) / Epiphyseal closure of the pacas humerus, radius and ulna (Agouti paca)

Background: After the capybara, the Agouti paca is the largest rodent in the neotropical region, with a body weight that usually varies from 5 to 10 kg, but may reach up to 14 kg. Pacas reach sexual maturity at around 10 months of age. Recently, this species has been increasingly being subject of studies on tissue morphology, placentation, and experimental surgery. The time at which epiphyseal plates close varies according to each bone; some can close during intrauterine life, while some can persist for many years. The aim of this research was to examine, through radiography, the long bones of the thoracic limbs (humerus, radius, and ulna) of the paca, and correlate their epiphyseal closure times with the animals age. Materials, Methods & Results: Eight animals born in captivity were radiographically evaluated monthly from birth until 22 months of age. The animals were kept in stalls made of masonry, with an area of approximately 15 m2 . Each stall had one burrow with three internal interconnected sub-sections. Each stall housed one male and two or three females with microchip implants applied dorsally in the cervical region. The animals were fed rodent chow (1.0% of body weight per day) and fruits of the season (10% of body weight per day), which were offered daily in the afternoon. The animals were radiographed at the Division of Radiology of the Veterinary Hospital of the School of Veterinary Medicine, São Paulo State University, Jaboticabal, SP, Brazil. Craniocaudal and mediolateral views of the humerus, radius, and ulna were performed. Sedation was performed using meperidine (2.5 mg/kg) and diazepam (0.5 mg/kg) in a single intramuscular injection. For anesthesia, ketamine (20 mg/kg) and xylazine (1.5 mg/kg) were administered in leg muscles 10 minutes after sedation. The anesthesia used proved to be efficient for transportation, handling, and positioning of the animals for radiographic exams.[...](AU)

Prenatal diagnosis and physical model reconstruction of agnathia-otocephaly with limb deformities (absent ulna, fibula and digits) following maternal exposure to oxymetazoline in the first trimester.

Agnathia-otocephaly or agnathia-sinotia-microstomy syndrome is the most severe malformation affecting the first branchial arch. It is a rare congenital anomaly characterized by absence of the lower jaw and abnormal ear positioning. Prenatal diagnosis is possible on conventional 2-D ultrasound in the second trimester. Three-dimensional ultrasound enhances detection of abnormal facial phenotype, especially in surface rendering mode. In addition, 3-D volume datasets are used to produce a physical model of the anomaly. We present a case of second trimester ultrasound diagnosis of agnathia-otocephaly associated with limb deformities. A physical model produced using 3-D ultrasound volume datasets facilitated better understanding of this congenital malformation, and improvement of parental counselling and management by the multispecialist team.

Safety and Efficacy of Derotational Osteotomy for Congenital Radioulnar Synostosis.

BACKGROUND: Congenital radioulnar synostosis (CRUS) refers to an abnormal connection between the radius and ulna due to embryological failure of separation. Derotational osteotomy has been advocated for children with functional limitations, although historically this procedure has been associated with a 36% complication rate including compartment syndrome and loss of correction. METHODS: A retrospective evaluation of consecutive patients who underwent derotational osteotomy for CRUS at a single institution was performed. Children with functional limitations secondary to excessive pronation were indicated for surgery with a goal of correction to 10 to 20 degrees of pronation. All patients were treated with a standardized surgical technique including careful subperiosteal elevation, rotational osteotomy at the level of the synostosis, control of the osteotomy fragments, appropriate pinning techniques, and prophylactic forearm fasciotomies. Electronic medical records, preoperative radiographs, and postoperative radiographs were reviewed. RESULTS: Derotational osteotomy was performed in 31 forearms in 26 children (13 bilateral, 13 unilateral) with a mean age of 6.8 years (range, 3.0 to 18.8 y). The mean clinical follow-up was 46 months (range, 6 to 148 mo). The mean preoperative pronation deformity was 85 degrees (range, 60 to 100 degrees). The mean correction achieved was 77 degrees (range, 40 to 95 degrees), resulting in a mean final position of 8 degrees of pronation (range, 0 to 30 degrees). All patients successfully achieved union by 8 weeks postoperatively. There were no cases of compartment syndrome, vascular compromise, or loss of fixation. The overall complication rate was 12% (2 transient anterior interosseous nerve palsies, 1 transient radial nerve palsy, 1 symptomatic muscle herniation). Both transient anterior interosseous nerve palsies occurred in patients with rotational corrections exceeding 80 degrees. CONCLUSIONS: Derotational osteotomy can be safely and effectively performed in children with CRUS. Meticulous surgical technique, including control of the osteotomy, judicious pin fixation, and prophylactic fasiotomies, may diminish the risk of neurovascular compromise and loss of correction. Transient anterior interosseous nerve palsies occurred, and may be related to large rotational corrections.

Comparison of Limestone and Ground Fish for Treatment of Nutritional Rickets in Children in Nigeria.

OBJECTIVE: To determine whether children with calcium-deficiency rickets respond better to treatment with calcium as limestone or as ground fish. STUDY DESIGN: Nigerian children with active rickets (n = 96) were randomized to receive calcium as powdered limestone (920 mg of elemental calcium) or ground fish (952 mg of elemental calcium) daily for 24 weeks. Radiographic healing was defined as achieving a score of 1.5 or less on a 10-point scale. RESULTS: The median (range) age of enrolled children was 35 (6-151) months. Of the 88 children who completed the study, 29 (66%) in the ground fish group and 24 (55%) in the limestone group achieved the primary outcome of a radiographic score of 1.5 or less within 6 months (P = .39). The mean radiographic score improved from 6.2 ± 2.4 to 1.8 ± 2.2 in the ground fish group and from 6.3 ± 2.2 to 2.1 ± 2.4 in the limestone group (P = .68 for group comparison). In an intention to treat analysis adjusted for baseline radiographic score, age, milk calcium intake, and serum 25-hydroxyvitamin D concentration, the response to treatment did not differ between the 2 groups (P = .39). Younger age was associated with more complete radiographic healing in the adjusted model (aOR 0.74 [95% CI 0.57-0.92]). After 24 weeks of treatment, serum alkaline phosphatase had decreased, calcium and 25-hydroxyvitamin D increased, and bone mineral density increased in both groups, without significant differences between treatment groups. CONCLUSION: In children with calcium-deficiency rickets, treatment with calcium as either ground fish or limestone for 6 months healed rickets in the majority of children.

A sonographic technique to evaluate the anterior bundle of the ulnar collateral ligament of the elbow: imaging features and anatomic correlation.

OBJECTIVES: The aim of this study was to test a sonographic technique used to view the anterior bundle of the ulnar collateral ligament (UCL), describe its sonographic characteristics in healthy volunteers, and verify these characteristics by determining interobserver variability and their correlations in cadavers. METHODS: Sonographic studies of the anterior bundle of the UCL were performed on 48 elbows of asymptomatic healthy volunteers. The participants were examined by 3 experts, who identified the insertion sites of the anterior bundle and subjectively evaluated its echogenicity and echo texture. A sonographic examination of the anterior bundle of the UCL in a cadaveric elbow was performed, and the same aspects were evaluated. RESULTS: In all cases, the anterior bundle of the UCL appeared as a triangular structure in the coronal plane and had a hyperechoic homogeneous echo texture in most of these cases. The cadaveric elbow had the same sonographic characteristics as the volunteers. CONCLUSIONS: As shown by examining the interobserver variability and determining the correlation with cadaveric tissue, sonography proved to be a reliable tool for evaluating the normal aspects of the anterior bundle of the UCL.

The role of US in the evaluation of clinically suspected ulnar collateral ligament injuries of the thumb: spectrum of findings and differential diagnosis.

Injury to the ulnar collateral ligament (UCL) complex of the thumb is a common traumatic lesion that requires prompt imaging evaluation for adequate treatment. In this article, we review the role of ultrasound in diagnosis and illustrate the spectrum of both static and dynamic findings related to the UCL injuries. We also describe a number of alternative diagnoses in the vicinity of the first metacarpophalangeal joint that may present clinically as pseudoligamentous lesions in a trauma setting.

Comparative analysis between three methods of bone estimating age in individuals with down syndrome by mode of the hand and wrist ray.

The wrist and hand region has been the most commonly used for estimating age and osseous development due to the great number of ossification centers. The aim was to determine which method, Tanner & Whitehouse's (TW3), Greulich & Pyle's (GP) or Eklof & Ringertz's, more closely relates to the chronological age in subjects with Down syndrome with chronological ages between 61 and 180 months, using wrist and hand radiographs. The sample consisted of 85 radiographs, 52 of males and 33 of females. Eklof & Ringertz's method was computerized (Radiomemory). Greulich & Pyle's atlas was used and compared with the wrist and hand radiographs. For the TW3 method, 13 ossification centers were evaluated; for each one of them, there are seven or eight development stages to which scores are assigned; these scores are then added and the results are transformed into osseous age values. No statistically significant differences were observed between the male and female genders for methods TW3 and GP, contrasting with the observed differences for the Eklof & Ringertz method. Correlation (r2) between osseous and chronological ages was 0.8262 for TW3 and 0.7965 for GP, while for the method of Eklof & Ringertz, it was 0.7656 for females and 0.8353 for males. The author concluded that the osseous age assessment method that better related to the chronological age was the TW3, followed by Greulich & Pyle's and Eklof & Ringertz's.

Osteotomy of the radius without shortening for Kienböck disease: a 10-year follow-up.

PURPOSE: To determine the long-term effect of distal radius osteotomy without modifying the radial length or inclination for Kienböck disease. METHODS: Over 9 years, 14 patients underwent osteotomy of the distal radius without altering radial length or inclination. A total of 11 of these patients were available for follow-up after 10 or more years. We assessed pain, range of wrist motion, and grip strength preoperatively and postoperatively in all cases, as well as preoperative and postoperative posteroanterior and lateral x-rays. RESULTS: The osteotomy healed in all cases. All 11 patients had decreased pain and showed improvement in wrist motion and grip strength. Radiographically, there were no measurable changes in ulnar variance and there was minimal loss of carpal height. In some patients, the lunate showed increased sclerosis or fragmentation. CONCLUSIONS: An osteotomy of the distal radius without altering radial length or inclination was effective in decreasing pain and improving grip strength and wrist motion regardless of ulnar variance.

Metaphyseal ulnar shortening osteotomy for the treatment of ulnocarpal abutment syndrome using distal ulna hook plate: case series.

PURPOSE: To determine the efficacy of a transverse ulnar-shortening osteotomy at the metaphysis in combination with osteosynthesis using a low-profile, 2.0-mm, locking compression distal ulna plate for the treatment of ulnocarpal abutment syndrome. METHODS: We enrolled into this prospective case series 6 patients with symptomatic ulnocarpal abutment syndrome without distal radioulnar joint ligamentous instability, who had previously failed conservative treatment. We recorded Quick Disability of Arm, Shoulder, and Hand score; wrist range of motion; and visual analog scale score for pain before and after surgery for statistical comparisons. RESULTS: All parameters improved after the surgery. The Quick Disabilities of the Arm, Shoulder, and Hand improved from a mean of 65 to 17, and the visual analog score improved from a mean of 7 to 2. No hardware removal was required and no complications were reported. CONCLUSIONS: Metaphyseal ulnar-shortening osteotomy provided the functional advantages of a midshaft ulnar-shortening osteotomy with the potential for improved bone healing and the reduced risk for complications. This technique was a useful alternative for treatment of ulnocarpal abutment syndrome, especially in patients with more than 2 mm ulnar positive variance. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Application of ultrasound for bone age estimation in clinical practice.

OBJECTIVE: To assess the validity of bone age assessment by ultrasonography (US). STUDY DESIGN: Wrist US was performed on children (n = 100) undergoing radiographic bone age and compared with bone age estimation by a radiologist in the clinic and by endocrinologists under blinded conditions with Greulich and Pyle (GP) and Tanner and Whitehouse (TW3) methods. RESULTS: The strongest correlation (r(2)) was seen in the radiographic bone age assessment between the 2 endocrinologists using the GP method (96.7%). The poorest correlation was seen when comparing radiographic methods to US of either wrist (74.6% to 82.6%). When bone age correlations were divided into normal, delayed or advanced, the highest correlation between the radiographic and US methods was found in the normal bone age group (80.9% to 86.1%) with weaker correlations for the delayed bone age group (77.1% to 86.9%) and the advanced bone age group (62.2% to 81.1%). US tended to overread delayed bone age and underread advanced bone age. US had poor positive and negative predictive value for identification of a normal or delayed bone age. The negative predictive value of US was 91% for an advanced bone age. CONCLUSIONS: On the basis of our data, US assessment should not yet be considered a valid replacement for radiographic bone age determination.

Eggshell membrane as a biodegradable bone regeneration inhibitor.

The efficiency of chicken eggshell membranes combined with a minimally invasive small osteotomy procedure of the ulna to accomplish an efficient release of the radius so that it can continue to grow in an unstressed manner was tested in rabbits. Eggshell membranes were extracted from chicken eggs, rinsed, dried and sterilized with ethylene oxide for 24 h. For reactivity testing, four separate subcutaneous pockets were created in 10 rats in the paravertebral region by blunt dissection and eggshell membranes were implanted in two of them. After 1-16 weeks, the implants were retrieved with the surrounding soft tissues and submitted to histological examination. Subsequently, 10 rabbits were anaesthetized and a complete 0.5 mm wide osteotomy was performed in both the right and the left distal ulna. A piece of eggshell membranes was interposed in the osteotomy site of one ulna. The opposite osteotomized ulna was left as a negative control. The rabbits were injected with oxytetracycline at the time of surgery and this was repeated every 7 days for labelling new bone formation. After 1-16 weeks, ulnar osteotomized regions were histologically examined. After histological, fluorescence microscopy and radiological evaluation, we demonstrate here for the first time that eggshell membranes as interpositional material in rabbit osteotomized ulnar experiments acted as an active barrier against bone bridging. The degradation of the eggshell membrane, due to host reaction, appeared sufficiently late to cause the desirable delay of bone healing that is compatible with the time needed for a corrective response.

A prospective study of the forearm bone density of users of etonorgestrel- and levonorgestrel-releasing contraceptive implants.

BACKGROUND: The aim of the study was to compare bone mineral density (BMD) before insertion and at 18 months of use of etonorgestrel- and levonorgestrel-releasing contraceptive implants. METHODS: One hundred and eleven women, 19-43 years of age, were randomly allocated to two groups: 56 to etonorgestrel and 55 to levonorgestrel. BMD was evaluated at the midshaft of the ulna and at the distal radius of the non-dominant forearm using dual-energy X-ray absorptiometry before insertion and at 18 months of use. RESULTS: There was no difference in baseline demographic or anthropometric characteristics, or in BMD of users of either model of implant. BMD was significantly lower at 18 months of use at the midshaft of the ulna in both groups of users. However, no difference was found at the distal radius. Multiple linear regression analysis showed that the variables associated with BMD at 18 months of use in both implant groups were baseline BMD, body mass index (BMI) and difference in BMI (0 versus 18 months of use). CONCLUSIONS: Women of 19-43 years of age using either one of the implants showed lower BMD at 18 months of use at the midshaft of the ulna, however, without a difference at the distal radius.