The scaphoid bone(also known as the hand navicular) is one of the largest carpal bones of the proximal and distal row and it lies beneath the anatomical snuff box in the wrist. It is situated between the hand and forearm (also called the lateral or radial side) on the thumb side of the wrist it is surrounded on the proximal side by the radius, on the distal lateral side by the trapezium bone, and on the distal medial side by the trapezoid bone. It forms the radial border of the carpal tunnel and superomedially, it articulates with the lunate bone and anteromedially with the capitate bone. The radial side of the wrist articulates with the radius, lunate, trapezoid, trapezium, and capitate bone covering 80% of the bone in articular cartilage. In the palm of the hand, its tubercle is easily palpable as it sits subcutaneously with a long axis being from above downward, lateralward, forward and the scaphoid bone slowly heals because of the limited circulation to the bone and poor muscle attachment. The blood supply of scaphoid bone is received primarily from lateral and distal branches of the radial artery, which are the branches of the palmar and dorsal artery of the wrist.
Bone
The palmar surface of the scaphoid is concave in shape and forms a tubercle easily palpable subcutaneously, giving attachment to the transverse carpal ligament.
The proximal surface is triangular in shape, smooth, convex area, and articulates with the radius and joining carpal bones, such as the lunate, capitate, trapezium, and trapezoid bone.
The lateral surface is a narrow bony surface and gives attachment to the radial collateral ligament.
The medial surface has two facets, one is a flattened semi-lunar facet articulating with the lunate bone, and another one is an inferior concave facet, both of two articulating with the lunate and the head of the capitate bone.
The dorsal surface of the bone is narrow in shape, with a groove running the narrow length of the bone and allowing ligaments to attach, and the surface facing the fingers.
The inferior surface is smooth and convex triangular in shape and divided into two parts by a slight ridge.
The scaphoid tubercle is a blunt, nonarticular hollowed projection for the capitate facet on the lateral edge of the bone. The tubercle is one of the attachment points for the flexor retinaculum, a fibrous band across the wrist joints for stabilization. The facet for the head of the capitate is the large concave shape facet on the proximal side of the scaphoid bone. The crescent-shaped facet for the lunate bone is also on the proximal side of the scaphoid but forms the medial edge of the bone. The radial facet is the single, convex shape facet on the distal end of the scaphoid. The facet for the trapezoid bone runs along the dorsolateral edge of the bone towards the tubercle of the scaphoid. The facet for the trapezium is at the lateral end of the dorsal side of the scaphoid bone.
References
Hamate Hook Fracture
Dr. Md. Harun Ar Rashid, MPH, MD, PhD, is a highly respected medical specialist celebrated for his exceptional clinical expertise and unwavering commitment to patient care. With advanced qualifications including MPH, MD, and PhD, he integrates cutting-edge research with a compassionate approach to medicine, ensuring that every patient receives personalized and effective treatment. His extensive training and hands-on experience enable him to diagnose complex conditions accurately and develop innovative treatment strategies tailored to individual needs. In addition to his clinical practice, Dr. Harun Ar Rashid is dedicated to medical education and research, writing and inventory creative thinking, innovative idea, critical care managementing make in his community to outreach, often participating in initiatives that promote health awareness and advance medical knowledge. His career is a testament to the high standards represented by his credentials, and he continues to contribute significantly to his field, driving improvements in both patient outcomes and healthcare practices.
