From the Guidelines
Dorsal palpation of the capitate is a crucial technique for assessing wrist injuries, particularly for evaluating carpal instability patterns and identifying potential fractures or ligamentous injuries, as it allows for the identification of the capitate as a rounded prominence on the dorsal aspect of the wrist. To perform this technique, have the patient's wrist slightly flexed to make the capitate more prominent. Place your thumb or index finger on the dorsal aspect of the wrist, approximately 1 cm distal to Lister's tubercle of the radius, in the middle of the wrist. The capitate can be identified as a rounded prominence in this location. Apply gentle pressure and you may feel the capitate move slightly when the wrist is moved into radial and ulnar deviation.
Key Points to Consider
- The capitate serves as an important landmark because it articulates with seven other bones (scaphoid, lunate, trapezoid, hamate, and the bases of the second, third, and fourth metacarpals) and is considered the keystone of the wrist.
- Tenderness over the capitate may indicate fracture, arthritis, or ligamentous injury affecting this central carpal bone.
- According to the American College of Radiology, MRI without IV contrast can detect fractures of the distal radius and carpal bones, including the capitate, and can lead to a change in diagnosis and patient management in some cases 1.
- However, the use of MRI in acute hand and wrist trauma has limited added value for determining which patients require surgery, and its use should be judiciously considered based on clinical presentation and physical examination findings 1.
From the Research
Dorsal Palpation of the Capitate
- The capitate bone is a carpal bone in the wrist that can be palpated using specific anatomical landmarks 2.
- A study found that the most successful methods of palmar capitate localization included the midpoint of a line from trapezium tubercle to pisiform, the midpoint of a line from scaphoid tubercle to hamate hook, or the intersection of these two diagonal lines, with successful capitate identification 100% of the time 2.
- However, there is limited research on dorsal palpation of the capitate, and most studies focus on palmar approaches or other aspects of capitate fractures and anatomy 3, 4, 5, 6.
- One study investigated the relationship between dorsal tilt, carpal malalignment, and capitate shift in distal radial fractures, but did not specifically address dorsal palpation of the capitate 5.
- Another study examined the effects of capitate height alteration on dorsal intercalated segment instability, but also did not focus on dorsal palpation 6.
Anatomical Relationships and Palpation
- The anatomical relationships between the capitate and other carpal bones are important for accurate palpation and localization 2.
- A cadaveric study found that the capitate can be localized using the midpoint of a line from the trapezium tubercle to the pisiform, or the midpoint of a line from the scaphoid tubercle to the hamate hook 2.
- These anatomical relationships can help clinicians improve their confidence in locating the capitate during intercarpal examination, special testing, and treatment 2.
Clinical Relevance and Further Research
- Further research is needed to evaluate the reliability and accuracy of methods for surface palpation on live patients, including dorsal palpation of the capitate 2.
- Clinicians should be aware of the anatomical relationships between the capitate and other carpal bones to improve their skills in palpation and localization 2.
- The development of new methods or techniques for dorsal palpation of the capitate may require further study and investigation 3, 4, 5, 6.