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Wheeless' Textbook of Orthopaedics
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Limb Development



- See:
      - Anatomy of the Physis
      - Deformities
      - Enchondral Ossification
      - Longitudinal Growth:
      - Pediatric Bone Circulation
      - Salter Harris

- Discussion:
    - at about the 4th week of development, paired upper and lower limb buds appear;
          - the upper limb bud appears at day 25-27;
          - at approx 47 days when the joints of the hand develop;
          - the lower limb bud appears at day 27-29;
    - each limb bud onsists of mesenchyme covered by ectoderm of lateral body wall;
          - mesenchyme of the limb bud derives from lateral body wall, & some if it migrated into limb bud from adjacent somites;
    - development of lower limb lags behind the upper limb;
    - limb buds bend ventrally at sites of future elbows and knees, leaving these structures pointing laterally
          while the palms and soles facing medially;
    - upper limbs then undergo external rotation while lower limb undergo internal rotation;









The Ectodermal Thickening and Ridge in the Limbs of Staged Human Embryos.
    R. O'Rahilly et al.   J. Embrylolgy Experimental Morphology. Vol 4, Part 3, p 254-264.

Development of the upper limb. Zaleske DJ. Development of the upper limb. Hand Clin 1985;1:383-390.

Reconstructing the history of human limb development: lessons from birth defects

The molecular control of upper extremity development: implications for congenital hand anomalies.








Original Text by Clifford R. Wheeless, III, MD.