Three cases of brachydactyly type E from two commingled tombs at the Late Intermediate period - Late Horizon site of Marcajirca, Ancash, Peru.

OBJECTIVE: Here we present the first known examples of brachydactyly from an Andean archaeological context by describing the affected bones, presenting a differential diagnosis, and discussing the cultural implications of there being shortened metapodials in multiple tombs. MATERIALS: 3232 well-preserved tubular bones representing an MNI of 250 human adults. METHODS: Each bone was visually inspected. Measurements were taken with an osteometric board, sliding calipers, and a flexible tape measure. RESULTS: Of 1210 metapodials excavated from eight burial contexts, ten were atypically short. CONCLUSIONS: The ten shortened elements represent an MNI of three individuals with brachydactyly from two tombs. The presence of at least two individuals with brachydactyly in one tomb adds support to a previous suggestion that tombs were used for familial interment. It is plausible that the third individual from a different tomb was related to the other two, and the different burial contexts may reflect postmarital practices. SIGNIFICANCE: These cases offer insight into tomb use and underscore the importance of identifying rare developmental anomalies in the archaeological record as their presence may indicate genetic relationships within or among archaeological cemeteries. LIMITATIONS: With commingled contexts and incomplete recovery of skeletal remains, individualizing the brachydactylous elements was not possible. There is also a lack of comparative data from other Andean sites. SUGGESTIONS FOR FURTHER RESEARCH: Identify more Andean cases of brachydactyly to learn if the relatively frequent involvement of the first digit is more common among Andean skeletal samples than North American, or if it is unique to Marcajirca.

A circular depression at the spinoglenoid notch of a prehistoric Andean scapula: Plausible evidence of suprascapular nerve entrapment by a paralabral cyst.

While intraosseous cysts have been described in the paleopathological literature, it is rare to find reports concerning effects of soft tissue cysts, although they are relatively common in clinical contexts. Here we present plausible evidence of an extraosseous paralabral cyst, seen in an adult scapula from a Late Intermediate period commingled tomb (ca. AD 1200) at the northern highland site of Marcajirca, Ancash, Peru. The scapula demonstrated a smooth-sided concave depression at the spinoglenoid notch. The depression was notable for its regular appearance, with no bone deposition or destruction. Rather than reflect an intraosseous pathology, the defect likely resulted from pressure erosion from a space-occupying mass. A narrow strip of flattened bone connected the depression to the posterior-superior aspect of the glenoid. The location and morphology of the depression and its connection with the glenoid are consistent with the effects of a paralabral cyst that arose secondary to a tear of the posterior-superior glenoid labrum. A labral tear may act as a one-way valve permitting fluid to flow along a path of least resistance, often to the spinoglenoid notch. A cyst at the spinoglenoid notch would compress the suprascapular nerve, causing weakened function of infraspinatus and its eventual atrophy.