From the Research
The sign for appendicitis when you bring your knee to your chest is called the psoas sign or iliopsoas sign. This test is performed by having the patient lie on their back while the examiner extends the patient's right leg at the hip, creating resistance. If this maneuver causes pain, it suggests irritation of the iliopsoas muscle, which can occur when the inflamed appendix lies adjacent to this muscle. The psoas sign is considered positive when pain increases with this movement, indicating possible appendicitis. This occurs because the inflamed appendix irritates the nearby psoas muscle, causing pain when the muscle is stretched.
The psoas sign is just one of several clinical signs used to diagnose appendicitis, along with others like McBurney's point tenderness, Rovsing's sign, and the obturator sign. These physical examination findings help clinicians evaluate the likelihood of appendicitis when a patient presents with abdominal pain, as noted in studies such as 1 and 2. According to 1, right lower quadrant pain, abdominal rigidity, and periumbilical pain radiating to the right lower quadrant are the best signs for ruling in acute appendicitis in adults.
In terms of diagnosis and management, the psoas sign is a valuable tool in the clinical assessment of appendicitis, particularly when used in conjunction with other signs and symptoms, as discussed in 2. The diagnosis of acute appendicitis is made in approximately 90% of patients presenting with classic symptoms, and laparoscopic appendectomy remains the most common treatment. However, increasing evidence suggests that broad-spectrum antibiotics may be an effective alternative in selected patients, as noted in 2.
It's worth noting that while the psoas sign is an important diagnostic tool, it should be used in conjunction with other clinical findings and imaging studies to confirm the diagnosis of appendicitis. As discussed in 3, the new palpation sign can be used to diagnose early and later stage appendicitis, especially in children and young women, and is very effective in indicating surgery for AA.
Overall, the psoas sign is a useful diagnostic tool in the assessment of appendicitis, and its use in conjunction with other clinical findings and imaging studies can help clinicians make an accurate diagnosis and develop an effective treatment plan, as supported by studies such as 1, 2, and 3.