RÉSUMÉ
Any congenital or acquired abnormality in the vertebral column is of interest for radiologist, orthopedician,forensic pathologist, neurologist and clinical anatomist. Such abnormality in the vertebrae may be eitherasymptomatic or may limit our movements because of the important structures related to them.During the osteology demonstration session for medical undergraduate students, we have found a few abnormalvertebrae of different regions of the spinal column.The clinical implications and embryological significance of these specimens is discussed here
RÉSUMÉ
Context: Lumbosacral transitional vertebrae (LSTV) are congenital anomalies that occur due to defect in normalsegmentation of the lumbosacral spine during development. This may be either in the form of assimilation offifth lumbar vertebra with the sacrum (sacralisation), or transition of the first piece of sacral vertebra into thelumbar configuration (lumbarisation).Aims and Objectives: Although presence of LSTV is common in general population but knowledge about its exactclinical implications is still lacking. The primary aim of the present study was to determine the rate of incidenceof transitional vertebra and their sex difference (if present) in dried human sacra. Secondary aim was to studythese transitional vertebra in detail and correlate these findings clinically.Materials and Methods: A total of fifty unbroken adult sacra were examined (male to female ratio of 3:2). Thepresence or absence of a lumbar transitional vertebra was noted and classified as incomplete or complete. Thesacral indices (SI) of all sacra were measured and values compared between typical and atypical sacra with LSTVas well as between male and female sacra.Results: Out of fifty sacra, six sacra (12%) showed presence of LSTV. Among them, four (8%) showed sacralisationof the fifth lumbar vertebra and two (4%) showed lumbarisation of first sacral vertebra. Among the four sacrashowing sacralisation, two showed incomplete fusion and two showed complete fusion of fifth lumber vertebrawith sacrum. LSTV was found to be more common in male than female. Sacralisation was seen only in male sacrawhile lumbarisation only in female sacra. The difference in the mean SI of typical sacra (97.76±4.08) and sacrawith LSTV (83.69±2.38 and 98.11±1.52 for sacralised and lumbarised sacra respectively) was found to bestatistically significant (p<0.05) and that between the male (94.55±5.70) and female (100.14±3.42) sacra wasfound to be highly significant (p<0.01).Conclusion: Presence of LSTV has many clinical and forensic implications and its knowledge is important fororthopaedic surgeons, neurosurgeons, forensic experts and also to radiologists.
RÉSUMÉ
In the lumbosacral region, anatomical variations occur with changes in the number of sacral vertebra either by deletion of first sacral vertebra or by the union of fifth lumbar or first coccygeal vertebra with sacrum. Lumbasacral transitional vertebrae (LSTV) is the most common congenital anomalies of the lumbosacral region. It most commonly involves the fifth lumbar vertebra showing signs of fusion to the sacrum known as sacralisation or the first sacral vertebra shows signs of transition to a lumbar configuration commonly known as lumbarisation. Complete transition can result in numerical abnormalities of the lumbar and sacral vertebral segments. Lumbarisation of first sacral vertebra is seen with a very low incidence of 2%. Knowledge of presence of such vertebral variation will be helpful for the clinicians to diagnose and treat patients with low back pain. Although sacralisation of fifth lumbar vertebrae is most commonly seen when compared to lumbarisation of first sacral vertebrae, we report here a case of lumbarisation of first sacral vertebrae for its rarity among the LSTV and clinical implications.
En la región lumbosacra, las variaciones anatómicas se basan en cambios en el número de las vértebras sacras, ya sea por ausencia de la primera vértebra sacra o por unión de la quinta lumbar o primera vértebra caudal con el sacro. Las vértebras de transición lumbasacra (VTLS) son las anomalías congénitas más frecuentes de la región lumbosacra. La VTLS más común se produce a nivel de la quinta vértebra lumbar, con signos de fusión al sacro, proceso conocido como sacralización; mientras que la primera vértebra sacra también puede mostrar signos de transición a una configuración lumbar. A esto último se lo denomina lumbarización. La transición completa puede provocar anomalías numéricas a nivel de los segmentos vertebrales lumbares y sacros. La lumbarización de la primera vértebra sacra se observa con una incidencia muy baja, de solo 2%. El conocimiento de la presencia de dicha variación vertebral será de utilidad para los médicos al momento de diagnosticar y tratar a los pacientes con dolor en la parte baja de la espalda. Aunque la sacralización de la quinta vértebra lumbar se produce más frecuentemente en comparación con la lumbarización de la primera vértebra sacra, se presenta aquí un caso de lumbarización de la primera vértebra sacra, rara entre las VTLS, y con implicaciones clínicas.