Significant Asymmetry of the Bilateral Upper Extremities of a Skeleton Excavated from the Mashiki-Azamabaru Site, Okinawa Island, Japan.

The human skeleton of a young adult male with marked asymmetry of the bilateral upper extremities was excavated from the Mashiki-Azamabaru site (3000-2000 BCE) on the main island of Okinawa in the southwestern archipelago of Japan. The skeleton was buried alone in a corner of the cemetery. In this study, morphological and radiographic observations were made on this skeleton, and the pathogenesis of the bone growth disorder observed in the left upper limb was discussed. The maximum diameter of the midshaft of the humerus was 13.8 mm on the left and 21.2 mm on the right. The long bones comprising the left upper extremity lost the structure of the muscle attachments except for the deltoid tubercle of the humerus. The bone morphology of the right upper extremity and the bilateral lower extremities was maintained and was close to the mean value of females from the Ohtomo site in northwestern Kyushu, Japan, during the Yayoi period. It is assumed that the anomalous bone morphology confined to the left upper extremity was secondary to the prolonged loss of function of the muscles attached to left extremity bones. In this case, birth palsy, brachial plexus injury in childhood, and acute grey matter myelitis were diagnosed. It was suggested that this person had survived into young adulthood with severe paralysis of the left upper extremity due to injury or disease at an early age.

Is Cam Morphology Found in Ancient and Medieval Populations in Addition to Modern Populations?

BACKGROUND: Cam morphology is thought to originate near puberty and reflects a response of the peripheral aspect of the proximal femoral physis to increased local load. Participation in particular sports activities has been associated with cam morphology in contemporary patient populations; however, it is unclear whether cam is a recent phenomenon. There are limited data regarding the frequency of its occurrence and the general deviations in femoral anatomy in different historical populations. Such information may help to understand the possible influence of lifestyle and diet on cam morphology. QUESTIONS/PURPOSES: The purpose of this study was to evaluate femoral morphology in three historical populations. We asked: (1) Was cam morphology present in the three study populations, did those populations differ, and were there differences between sexes? (2) Were there differences in neck-shaft angle, version, or inclination between and among the examined populations? METHODS: We examined 204 adult femurs from the Neolithic population from Iran (n = 37, 3000 BC to 1631 BC), medieval population from Poland (n = 135, 10th to 13th centuries), and contemporary Australian aborigines (n = 32, early 20th century), provided by the Open Research Scan Archive, Museum of the First Piasts at Lednica and the University of Wroclaw, respectively. All three human populations represent different chronologic periods and lifestyles. All bones were scanned using CT and then measured on their three-dimensional (3-D) reconstructions in selected planes. Cam impingement was defined as an alpha angle > 55° measured on the inclination view. To evaluate the differences in anatomy between populations, we measured the true neck-shaft angle on the true AP view, apparent neck-shaft angle on the apparent AP view, the version angle on the version view, and the inclination angle on the inclination view. The prevalence of cam morphology and other anatomic parameters were compared among groups using chi-square test, one-way ANOVA with post hoc Tukey test, and paired t-test. RESULTS: Cam morphology was present in 5% of the Neolithic population from Iran, in 7% of the medieval population from Poland, and 3% of the contemporary Australian aborigine femurs (OR Neolithic population from Iran/the medieval population from Poland 0.7 [95% CI 0.2 to 3.4]; p = 0.67; OR Neolithic population from Iran/contemporary Australian aborigines 1.8 [95% CI 0.2 to 20.5]; p = 0.65; OR the medieval population from Poland/contemporary Australian aborigines 2.5 [95% CI 0.3 to 20.1]; p = 0.40). There were differences in the presence of cam morphology between the sexes in the medieval population from Poland with both femurs (females: 1% [1 of 76]; males: 15% [9 of 59]; p = 0.002). There was a difference in true neck-shaft angle between the Neolithic population from Iran (121° ± 6°) and contemporary Australian aborigines (131° ± 5°; mean difference 10° [95% CI 7° to 13°]; p < 0.001) and between the medieval population from Poland (124° ± 5°) and the contemporary Australian aborigines (mean difference 7° [95% CI 5° to 9°]; p < 0.001). Apparent neck-shaft angle differed between the Neolithic population from Iran (126° ± 6°) and the contemporary Australian aborigines (134° ± 5°; mean difference 8° [95% CI 6° to 11°]; p < 0.001), and between the medieval population from Poland (126° ± 6°) and the contemporary Australian aborigines (mean difference 9° [95% CI 7° to 11°]; p < 0.001). Moreover, we observed a difference in the version angle between the Neolithic population from Iran (19° ± 7°) and the medieval population from Poland (12° ± 9°; mean difference 7° [95% CI 4° to 10°]; p < 0.001] and in the inclination angle between aforementioned groups (18° ± 7° versus 11° ± 8°; mean difference 7° [95% CI 5° to 10°]; p < 0.001). CONCLUSION: This study found that cam morphology existed in historical populations at rates comparable with a contemporary population. CLINICAL RELEVANCE: The presence of cam morphology in historical populations suggests that cam morphology can develop outside of the intense sports activity seen in modern adolescents. Further study will help elucidate the etiology of cam morphology, which may be useful in the development of preventive strategies.