Differential Diagnosis for Somatic Dysfunction
Single Most Likely Diagnosis
- Right sacroiliac joint dysfunction with restricted motion on the left: This is the most likely diagnosis because the movement of the PSIS (posterior superior iliac spine) on the right side when standing suggests a normal or relatively normal sacroiliac joint on that side. Conversely, the lack of movement on the left suggests a restriction or dysfunction in the left sacroiliac joint, which could be due to various reasons such as inflammation, trauma, or biomechanical issues.
Other Likely Diagnoses
- Left ilium rotation or fixation: This could be another likely diagnosis as it would restrict the normal movement of the PSIS on the left side. The ilium's position and movement are closely related to the sacroiliac joint's function, and any abnormal rotation or fixation could lead to the observed lack of PSIS movement.
- Lumbar spine or pelvic ring dysfunction: Dysfunction in the lumbar spine or the pelvic ring could also affect the movement of the PSIS. For example, a lumbar spine fixation or a pelvic ring dysfunction could alter the normal biomechanics of the pelvis, leading to restricted movement of the PSIS on one side.
Do Not Miss Diagnoses
- Sacroiliac joint infection or septic arthritis: Although less common, an infection in the sacroiliac joint could cause severe pain and restriction of movement. Missing this diagnosis could lead to serious complications, including joint destruction and long-term disability.
- Pelvic fracture or stress fracture: A fracture in the pelvis, including stress fractures, could also restrict the movement of the PSIS. This is particularly important in individuals with a history of trauma or those who engage in high-impact activities.
Rare Diagnoses
- Sacroiliac joint tumors or cysts: Tumors or cysts affecting the sacroiliac joint are rare but could cause somatic dysfunction by restricting joint movement or causing pain.
- Congenital anomalies of the pelvis or sacroiliac joint: Certain congenital anomalies could affect the normal development and function of the sacroiliac joint, leading to somatic dysfunction. These are rare and typically identified early in life but could be a consideration in some cases.