Spondylolysis in the past: A case study of hunter-gatherers from Southern Patagonia.

Spondylolysis is a fracture of the pars interarticularis, the portion of the neural arch that lies between the superior articular facets and the inferior articular facets. Clinical evidence has suggested repetitive trauma to be the most probable cause, even though morphological weakness of the vertebra is probably also involved. Prevalence is between 3% and 8% in modern populations, while in archaeological samples it varies from 0% to 71.4%. Considering that very little data about this condition is available in past populations from the southern extreme of South America, the aim of this paper is to analyze the spondylolysis in a human skeletal sample from Southern Patagonia and, at the same time, to explore the prevalence of spondylolysis in archaeological contexts around the world to gain a better understanding of the results presented here. The Southern Patagonian skeletal series analyzed here showed a prevalence of 20%, with lower prevalence in the pre contact sample (11.1%) than in the contact period (23.1%). Skeletons from the Salesian Mission "Nuestra Señora de La Candelaria" showed a higher prevalence (25%) than the sample of skeletal remains recovered from outside the mission (20%), suggesting that changes in lifestyle of hunter-gatherers during contact could be implicated in the development of spondylolysis in this sample. A worldwide survey displays a wide range of prevalence figures in American and Asian samples and low diversity between African and European populations. Hunter-gatherers from Southern Patagonia showed similar values to those observed in other American samples.

Spondylolysis, spondylolisthesis, and lumbo-sacral morphology in a medieval English skeletal population.

The prevalence of spondylolysis and spondylolisthesis was studied in an adult skeletal series from a rural English medieval archaeological site. Attempts were made to evaluate the association of three aspects of lumbo-sacral skeletal morphology (pelvic incidence (a measure of the anterior inclination of the sacral table), lumbar transverse process width, and the presence of lumbo-sacral spina bifida occulta) with spondylolysis and spondylolisthesis. Results indicated a high prevalence of spondylolysis compared with a modern reference population, but few cases of spondylolisthesis were identified. Analysis of prevalence with respect to age suggests that in the study population, pars interarticularis defects generally formed late in the growth period or early in adult life. The study group showed a high mean pelvic incidence compared with modern Western Europeans, indicating a more steeply inclined sacral table, which may have elevated the risk of developing pars interarticularis defects. However, no statistically valid association could be demonstrated between the presence/absence of spondylolysis and pelvic incidence in the study material. There was no evidence for a link between lumbar transverse process index or lumbo-sacral spina bifida occulta and spondylolysis/spondylolisthesis. It is concluded that the potential role of lumbo-sacral morphology, as well as of activity regimes, should be considered when interpreting spondylolysis in paleopathological studies. If the frequency of spondylolysis is to some extent an indicator of past activity regimes, it may reflect lifestyle in younger individuals rather than in mature adults. Further work investigating the link between spondylolysis and lumbo-sacral morphological variables in premodern populations would be of value.

Asymmetrical spondylolysis.

The objective of this study was to examine examples of spondylolysis in which the pattern of separation was clearly asymmetrical, in order to learn more about the process of bone separation that produces this condition. Although the primary focus was on unilateral complete separation, examples of asymmetry represented by incomplete separation and by complete bilateral separation where the separation sites are in different locations on the two sides were included. Two collections were used, one consisting of Canadian Inuit skeletons curated at the Canadian Museum of Civilization, and the other of 48 individual examples of asymmetrical spondylolysis from sites in a variety of localities curated by several different institutions. The first collection was studied primarily to observe early manifestations of spondylolysis, particularly incomplete separation, while various patterns of asymmetrical complete separation were the focus of the second. The results indicate that asymmetry is part of the earliest osteological picture of spondylolysis, with right-sidedness predominating, a condition perhaps related in some way to handedness. The right-side predominance appears to decrease with age. The ratio of unilateral to bilateral separation ranges from 3-33% in different studies, and a significant number of the unilateral separations have spina bifida occurring in the same vertebra. Overall, the specimens examined here, considered along with clinical cases, nicely illustrate a progression of spondylolysis. A unilateral separation may heal, it may progress to bilateral separation, or it may remain as a permanent condition, producing a pattern of degenerative changes that can include spondylolisthesis. A unilateral healing of bilateral complete separation is likely a rare phenomenon, at least after the separations have reached a certain level of maturity.

Spondylolysis in prehistoric human remains from Guam and its possible etiology.

This study reports the findings of complete bilateral separation of the neural arch (spondylolysis) in 176 inhumations from the Hyatt Site, Tumon Bay, which is located on the west side of the island of Guam. Skeletons were excavated and analyzed by the Paul H. Rosendahl Inc. (PHRI) team in 1989-1990. The inhumations were associated with the pre-European Latte Period (circa 1,200-1,521 A.D.). This period was characterized by the use of large stone pillars, called latte sets, for the construction of houses. Of the 176 individuals, only 38 adult skeletons had complete spines, and 21% (8/38) of these had evidence of spondylolysis in their lumbar vertebrae, particularly in L-5. The age of the eight individuals range from 30 to 50 years. No children were found with spondylolysis. Of the males 29.4% (5/17) had spondylolysis, as did 14.3% (3/21) of the females. However, the difference between the sexes was not statistically significant. Though the sample is small, it is suggested that the high incidence of lumbar spondylolysis found in these ancient Chamorros was related to lower back traumatic events. The transport of latte stones, involving hyperextension and torque of the lower back, while dragging the stones, probably contributed to the development of microfractures in the spine and subsequent spondylolysis. If this hypothesis is correct, then both males and females appear to have been participants in an organized community labor force. It is predicted that similar frequencies of spondylolysis will be found at other Latte sites.

Incomplete spondylolysis and healing. A study of ancient Canadian Eskimo skeletons.

STUDY DESIGN: Skeletons of ancient Canadian Eskimos subjected to arctic weathering presented an unusual opportunity for direct observation of all stages of spondylolysis. OBJECTIVE: To explore early stages of incomplete lysis, a phenomenon difficult to observe radiographically. SUMMARY OF BACKGROUND DATA: Although lumbar spondylolysis most often appears to be a stress fracture that may proceed to complete separation, its early stages have been difficult to visualize. METHODS: Vertebrae were examined for even minute lytic defects in the general region of pars interarticularis and the results were correlated with age at death. RESULTS: Spondylolysis was found in 51 individuals, with 110 separate sites (sides) affected. At 34 of these sites, all but two in adolescents or young adults, the lysis was incomplete. Incomplete lysis affected the superior margin of the neural arch more often than the inferior margin, and the right side more often than the left. CONCLUSION: Spondylolysis first became recognizable as incomplete stress fractures during adolescence, with most progressing to complete lysis in young adulthood. New fractures continued to develop in young adults, but most healed by middle adulthood. After 45 years of age, the overall frequency of spondylolysis declined, indicating that even complete defects occasionally healed.

Spondylolysis. An historical review.

This historical review covers the earliest recorded findings and descriptions of lumbar spondylolysis, as well as the century-old etiologic controversy regarding this condition. The importance of the work of Robert zu Coblenz in 1855 is recognized regarding the biomechanical and clinical understanding of the nature of spondylolysis. Other important medical personalities are discussed through an extensive look at the literature.

Variations in the prevalence of spondylolysis in early British populations.

Crude prevalence rates of spondylolysis were estimated in skeletal populations from various periods. There was a steady increase in prevalence from 3.74% in Romano-British to 5.08% in medieval populations, but the rate fell considerably to 1.42% in a population from an 18th/19th century context. This trend was not statistically significant, however. The male/female ratio was approximately unity until the 18th/19th century when the expected male excess appeared. The lesions predominantly affected L5 and all were isthmic in type. Of the total of 52 cases, only four were unilateral. One occurred in the fourth cervical vertebra. There were few complications; spondylolisthesis was noted in four cases and in three there were osteoarthritic changes on the superior margin of the displaced lamina.

Spondylolysis and its relationship to degenerative joint disease in the prehistoric southeastern United States.

Spondylolysis, a fatigue fracture in the neural arch of lumbar vertebrae, is common in Eskimos and some athletes. In Archaic Indians from northwestern Alabama, 17% of males and 20% of females with complete lumbar regions showed this defect. It is found at a fairly early age in adult males in this group, but in females it does not appear until after age 40 years. Spondylolysis is associated with higher levels of osteoarthritis around the fifth lumbar vertebra, where this defect typically occurs. Otherwise, there is little relationship between its presence and degenerative joint disease, especially in the weight-bearing joints. The incidence in young males may be related to activities necessitating a high level of mobility around the lumbar spine. The late occurrence in females suggests that osteoporosis may have been a contributing factor.

[Unilateral spondylolyses in Slavic and Slavic-Avaric populations]. / Unilaterale Spondylolysen bei slawischen und slawisch-awarischen Populationen.

The authors consider the spondylolysis a polyetiologic abnormality with an important part of congenital factors in its origin. The frequency of spondylolysis can be considered a feature characterizing a population. This opinion is confirmed by finds in skeletal materials from old Slavonic and Slavonic-Avaric cemeteries. The frequency of spondylolysis in the Slavonic part is significantly lower than in the Slavonic-Avaric part of the materials. The share of unilateral spondylolysis is also different (15 and 7%) when comparing these two population groups, but statistically insignificant. The so-called "combined" type of spondylolysis is, however, significantly higher in the number of unilateral cases of spondylolysis than in the bilateral ones.