Related Experiment Video
Updated: May 31, 2026

Micro-Computed Tomography Analysis of the Knee in Aged Dunkin-Hartley Guinea Pigs after Intra Articular Injection
Published on: August 2, 2024
Tubular anomalous bones found in both thighs of a long-tailed macaque (Macaca fascicularis)
Yuzuru Hamada1, Junmei Sawada, Fumiaki Cho
1Evolutionary Morphology Section, Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan. hamada@pri.kyoto-u.ac.jp
Abstract:
Tubular anomalous bones were found in both thighs of a 6-year-old male long-tailed macaque (Macaca fascicularis) bred in captivity. The bones had jagged ends and protruded from the skin. Radiographs showed that they developed in the femurs at the middle and elongated. They were removed with surgery under anesthesia. Histological analysis revealed that these bones had the same histological structure as the femur, though they were composed of primary and secondary osteon regions. This finding indicated that the new bones developed from the old bone piece(s), acquired a tubular shape, and elongated. It is suggested that the anomalous bones were produced not by the congenital deformity but by regeneration from fragments of the fractured femur that were embedded in the bone marrow; these acquired a tubular pattern and elongated.
Related Concept Videos
Bones of the Lower Limb: Tibia and Fibula
Bones of the Lower Limb: Femur and Patella
Classification of Bones
Long and Short Bones
The appendicular skeleton, particularly the upper and lower limbs, is primarily made of long and short bones. The long...
Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Overview of the Axial Skeleton
The axial skeleton of the adult...
Bones of the Upper Limb: Humerus

