Abstract
Background: Cervical ribs are congenital anomalies that are usually found on the seventh cervical (C7) vertebrae, but has been found at the sixth and fifth cervical vertebrae. These cervical ribs can occur unilaterally or bilaterally and in rare cases they can be symmetrical. Studies show the prevalence of cervical ribs occur among 0.5% and 6.2% of the population in various countries. This study focused on determining the prevalence of cervical ribs in the South African population in hopes to determine how often cervical ribs might appear in a clinical setting.
Aim: The aim of the study is to determine the prevalence of cervical ribs in the South African population, specifically if the cervical ribs found are unilateral or bilateral, whether cervical ribs are more prominent in males or females, and classifying the ribs with the added classification of hyperplastic TVPs of C7.
Method: Two hundred skeletons in the Raymond A. Dart Collection of Modern Human Skeletons at the University of the Witwatersrand were examined for the presence of a cervical rib(s), and in addition to the initial conclusion, measurements of each C7 and T1 TVP was taken to further refine the classification of hyperplastic TVPs at C7 level. The relevance of this would be to determine if there is a correlation in the TVP length in the presence of a cervical rib and also to determine whether a hyperplastic TVP can have clinical implications.
Procedure: Skeleton containing boxes were examined systematically to determine if the C7 and T1 vertebrae were present or damaged, measurements were then taken of the TVPs of C7 and T1 and documented. On account of damaged or incomplete vertebrae, 520 boxes were drawn and scanned to complete the sample of 200 intact boxes that could be included.
Results and discussion: Two hundred skeletons were examined and measured and six cervical ribs were identified and classified according to the four types. In addition to the measurements, six additional hyperplastic ribs were classified where the length of the C7 TVP was 2mm longer than the T1 TVP on the same side of the same skeleton. The prevalence before measurements were included was 3%, and with the additional six cervical ribs it came to 6%.
Conclusion: The prevalence of cervical ribs in the South African population is on the higher side compared to the prevalence of cervical ribs as described in other populations. The measurements provided some statistical data of the C7 TVP, which is elongated when a cervical rib is
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present, as well as classifying hyperplastic TVPs. The study could not draw any conclusion on the correlation between the prevalence of cervical ribs, hyperplastic TVPs and clinical implications due to the study type.
Keywords: Cervical ribs, TVPs, hyperplastic TVP, measurements.