Patterns of Rib Growth in the Human Child

The effect of Scheuermann's kyphosis on rib cage morphology: A skeletal study

BACKGROUND

Evolutionary changes in human rib cage morphology rendered it prone to pathologies like Scheuermann's kyphosis (SK). However, the impact of SK on rib cage morphology is unclear.

PURPOSE

This study aimed to examine differences in rib cage morphology (e.g., ribs and sternum) between SK patients and a control group.

METHODS

Measurements of the vertebral body, transverse process angle, sternum, and rib size were taken from the skeletons of SK patients (76) and a control group (96). Statistical tests were carried out to examine differences between the study and control groups and between the right and left sides. Correlations were obtained to examine the associations between the extent of the kyphosis (kyphosis angle) and rib cage variables.

RESULTS

The SK group yielded significantly longer and flatter ribs than the control group in both sexes. However, males had the largest differences in the 9th rib and females in the upper ribs (5-7). Inconsistency in symmetry results was found between the sexes. In summary, SK patients had a larger anteroposterior diameter in relation to the transverse diameter than the control group.

DISCUSSION AND CONCLUSIONS

SK affects the morphology of the entire thorax and changes rib proportions similarly in males and females. These changes might have a role in bipedal stability and locomotion efficiency. Moreover, understanding the unique anatomy of SK patients is essential when performing an anterior release and anterior fusion operative approach. Finally, it provides insights into respiratory complications and poor prognosis related to individuals suffering from severe hyperkyphosis.

Ontogenetic changes to bone microstructure in an archaeologically derived sample of human ribs

There is considerable variation in the gross morphology and tissue properties among the bones of human infants, children, adolescents, and adults. Using 18 known-age individuals (n_female  = 8, n_male  = 9, n_unknown  = 1; birth to 21 years old), from a well-documented cemetery collection, Spitalfields Christ Church, London, UK, this study explores growth-related changes in cortical and trabecular bone microstructure. Micro-CT scans of mid-shaft middle thoracic ribs are used for quantitative analysis. Results are then compared to previously quantified conventional histomorphometry of the same sample. Total area (Tt.Ar), cortical area (Ct.Ar), cortical thickness (Ct.Th), and the major (Maj.Dm) and minor (Min.Dm) diameters of the rib demonstrate positive correlations with age. Pore density (Po.Dn) increases, but age-related changes to cortical porosity (Ct.Po) appear to be non-linear. Trabecular thickness (Tb.th) and trabecular separation (Tb.Sp) increase with age, whereas trabecular bone pattern factor (Tb.Pf), structural model index (SMI), and connectivity density (Conn.D) decrease with age. Sex-based differences were not identified for any of the variables included in this study. Some samples display clear evidence of diagenetic alteration without corresponding changes in radiopacity, which compromises the reliability of bone mineral density (BMD) data in the study of past populations. Cortical porosity data are not correlated with two-dimensional measures of osteon population density (OPD). This suggests that unfilled resorption spaces contribute more significantly to cortical porosity than do the Haversian canals of secondary osteons. Continued research using complementary imaging techniques and a wide array of histological variables will increase our understanding of age- and sex-specific ontogenetic patterns within and among human populations.

Impact of Thoracic Cage Dimension and Geometry on Cardiopulmonary Function in Patients With Congenital Scoliosis: A Prospective Study

STUDY DESIGN

A prospective study of cardiopulmonary function in patients with congenital scoliosis (CS).

OBJECTIVE

To investigate the relationship of thoracic cage deformity and exercise tolerance in CS patients.

SUMMARY OF BACKGROUND DATA

Congenital thoracic scoliosis and chest deformity lead to restrictive pulmonary dysfunction and in some severe cases cause cardiopulmonary failure. However, it is still unknown the relationship between thoracic deformity and exercise performance.

METHODS

Patients with congenital thoracic spinal deformity were included and had radiological assessment of thoracic cage, pulmonary function testing, and cardiopulmonary exercise testing. Thoracic dimension including height, width, and depth were measured and geometry parameters were calculated. Two-tailed Pearson and Spearman correlation test and linear regression analysis were performed to investigate correlation of radiographic parameters, pulmonary function, and physical capacity.

RESULTS

Sixty patients (41 females and 19 males) were included, with an average age of 18.9 years. Patients with smaller thoracic height (P < 0.001) and width (P < 0.01) and larger depth (P < 0.05) had significantly worse static pulmonary function. In exercise testing, these patients showed significant tendency of ventilation insufficiency, including lower minute ventilation (P < 0.05), faster breathing frequency (P < 0.05), and smaller tidal volume (P < 0.01). Thoracic depth was negatively correlated to exercise capacity, reflected by work rate (P < 0.001), peak oxygen intake (P < 0.001), and heart rate (P = 0.043). Patients with abnormal thoracic geometry, especially a lower ratio of height to depth and a lower ratio of width to depth, have significantly worse static pulmonary function and exercise capacity (all P < 0.05).

CONCLUSION

Decreasing thoracic height and width results in restrictive pulmonary dysfunction. Distortion and asymmetry of the thoracic cage are associated with abnormal breathing pattern and reduction of exercise capacity.

LEVEL OF EVIDENCE

3.

Evaluation of the Golden Ratio in Nasal Conchae for Surgical Anatomy

PURPOSE

The golden ratio is reached by the fractal model of the number sequence which is known as the "Fibonacci series" and has a convergent ratio of approximately 1.618 between 2 consecutive Fibonacci numbers. Golden ratio relationships have been shown in several plants in the nature and several organs and structures in the human body. The conchae, which form an important part of the nasal valve, have a special geometric significant in terms of providing turbulence to the laminar airflow that passes to the nasal cavity.

METHODS

This study made golden ratio calculations on 34 adults aged 20 to 45 years over computed tomography (CT) images. Totally, 34 volunteers (male, n = 18 and female, n = 16) with no nasal pathologies participated in the study. Using Adobe Photoshop, golden ratio calculations were made by applying the Fibonacci spiral on the images that best showed the conchae and meatuses on the CT images.

RESULTS

The intersection points of the spiral that was projected on the inferior and middle nasal concha were determined as S0, S1, S2, S3, and S4. The distances of S0-S1, S1-S2, S2-S3, and S3-S4 were measured. The concha measurements of the women showed significantly similar values to the golden ratio constant of ∼1.618 in the RS3/S4 and LS3/S4 measurements.

CONCLUSION

We found that the S3/S4 region that captured the golden ratio in our study corresponds to the base part of the inferior nasal concha, and its place of spiraling in the nasal cavity is observed to have an important role in creating vortices.

Growth Patterns of the Neurocentral Synchondrosis (NCS) in Immature Cadaveric Vertebra

STUDY DESIGN

Gross anatomic study of osteological specimens.

OBJECTIVES

To evaluate the age of closure for the neurocentral synchondrosis (NCS) in all 3 regions of the spine in children aged 1 to 18 years old.

SUMMARY OF BACKGROUND DATA

The ossification of the human vertebra begins from a vertebral body ossification center and a pair of neural ossification centers located within the centrum called the NCS. These bipolar cartilaginous centers of growth contribute to the growth of the vertebral body, spinal canal, and posterior elements of the spine. The closure of the synchondroses is dependent upon location of the vertebra and previous studies range from 2 to 16 years of age. Although animal and cadaveric studies have been performed regarding NCS growth and early instrumentation's effect on its development, the effects of NCS growth disturbances are still not completely understood.

METHODS

The vertebrae of 32 children (1 to 18 y old) from the Hamann-Todd Osteological collection were analyzed (no 2 or 9 y old specimens available). Vertebrae studied ranged from C1 to L5. A total of 768 vertebral specimens were photographed on a background grid to allow for measurement calibration. Measurements of the right and left NCS, pedicle width at the NCS, and spinal canal area were taken using Scandium image-analysis software (Olympus Soft Imaging Solutions, Germany). The percentage of the growth plate still open was found by dividing the NCS by the pedicle width and multiplying by 100. Data were analyzed with JMP 11 software (SAS Institute Inc., Cary, NC).

RESULTS

The NCS was 100% open in all 3 regions of the spine in the 1- to 3-year age group. The cervical NCS closed first with completion around 5 years of age. The lumbar NCS was nearly fully closed by age 11. Only the thoracic region remained open through age 17 years. The left and right NCS closed simultaneously as there was no statistical difference between them. In all regions of the spine, the NCS appeared to close sooner in males than in females. Spinal canal area increased with age up to 12 years old in the cervical and thoracic spine but did not significantly change after age 3 in the lumbar spine.

CONCLUSIONS

In conclusion, closure of the NCS differed among the cervical, thoracic, and lumbar spine regions. The NCS reached closure in males before females even though females mature faster and reach skeletal maturity sooner than males. However, it is not determined whether the continued open NCS in females to a later age may be a factor in their increased rate of scoliosis.