Sharp-Purser test is a cervical spine examination procedure that tests for possible orthopaedic subluxation of the Atlas that has reduced. This test assesses the stability of the Atlanto-Axial joint and stabilizers of the dens of Atlas. It specifically assesses the integrity of the Transverse ligament. Instability of the Atlantoaxial joints is a hallmark complication of rheumatoid arthritis in the cervical spine.
Patient should be awake and cooperative to perform the Sharp-Purser test.
- Patient should be seated during the examination.
- The examiner stabilizes the patient’s head with his hand over the patient’s forehead.
- The examiner uses his thumb on his other hand over the spinous process of C2 (axis).
- The patient flexes her head forward as the examiner applies gentle A-P pressure on the patient’e’ forehead.
- The examiner checks for the patient’s head sliding backwards or unusual noises while performing the motion.
Positive Sharp-Purser Test
There is a positive Sharp-Purser test when the patient’s head slides backwards during the procedure and/or a “clunk” with motion. These signs could indicate orthopaedic subluxation of the Atlas that has reduced.
Examiners should perform the Sharp-Purser test with extreme caution because there are sensitive structures along the area. If there is suspected subluxation or a positive test result, diagnostic imaging must be done. Radiographs of the cervical flexion and extension views should be done ASAP.