Scenario
A patient visited the clinic and presented signs of hyperinternal rotation of the femur followed by an acute onset of pain. The patient, who is an athlete, presented with pain deep in the posterior aspect of the hip that radiated into the buttock and down the posterior aspect of the thigh. Piriformis Syndrome is suspected. While Piriformis Syndrome is not commonly-diagnosed due to better diagnostic tests for lumbar nerve root impingement and intervertebral disk disease. However, if the patient is a woman -- especially an athletic one -- this is a possible pathology worth investigating. Piriformis Syndrome, however, still remains undefined and its manifestations a bit confusing (Starkey et al., 2010, p. 448). However, its onset is acute and can occur secondary to hypertrophy of the piriformis muscle or biomechanical changes in the hip, pelvis, or sacrum. The pain manifests deep in the posterior aspect of the hip and radiates down the buttock and down the posterior aspect of the leg. Generally, the pain increases upon standing (Starkey et al., 2010, p. 449). A blow to the buttock, a hyperinternal rotation of the hip, or possibly some other trauma, can cause Piriformis Syndrome.
Based on the patient's reported symptoms and a history of athleticism, tests for Piriformis Syndrome will be given. The first test, which is palpation, would reveal tenderness at the sciatic notch and an association of increased symptoms may be reported, if positive. Other complaints could include numbness, burning, or paresthesia and may be reported, should they be accompanied by prolonged sitting or palpation. Another palpation may be called for -- a palpation of the sciatic nerve. By locating the greater trochanter and the ischial tuberosity, the sciatic nerve's approximate course can be traced as the nerve is roughly midway between these two structures (Starkey et al., 2010, p. 425).
Next, a joint and muscle examination, which includes Active Range of Motion (AROM), Manual Muscle Test (MMT), and Positive Range of Motion (PROM) would be conducted.
The AROM, if Priformis Syndrome is the cause of the presenting signs and symptoms, should reveal pain during the external rotation of the femur, which is due to the piriformis muscle's contraction and its resultant pressure on the sciatic nerve (Starkey et al., 2010, p. 449).
If Piriformis Syndrome is present, the MMT will reveal increased pain while the patient is seated during resisted external hip rotation. Further MMT testing such as pain during resisted hip abduction may also present itself (Starkey et al., 2010, p. 449).
Should Piriformis Syndrome be the cause of this particular patient's sciatica, the PROM will increase pain symptoms while the patient is supine (with hip and knee flexed to 90 degrees) and passive internal rotation of the hip is also conducted (Starkey et al., 2010, p. 449). To test PROM, the patient is seated with knees flexed over the edge of the table and a bolster is placed under the distal femur to keep it parallel with the tabletop.
With the leg perpendicular to the ground, the patient's arms are extended and support the torso on the table (Starkey et al., 2010, p. 435). One of the primary movers (for innervation) is the piriformis muscle. A positive result from this test could reveal increased sciatic pain as the piriformis places pressure on the sciatic nerve. The patient may complain of increased pain in the region of the buttocks.
A special test called the positive straight-leg-raise or resisted hip abduction while seated will also exacerbate pain in the piriformis as well as increase the pain caused by the accompanying sciatica.
Neurologic screening is also important. For example, L2-L4 dermatomes need to be tested for numbness or paresthesia. A differential diagnosis may reveal nerve root compression between L2 and L4.
Joint stability tests such as stress tests and joint play are not applicable and do not need to be assessed in order to diagnose Piriformis Syndrome. Moreover, vascular screening must be within normal limits (Starkey et al., 2010, p. 449).
A functional assessment should also be conducted. For example, the patient, in many instances, will present with symptoms of increased pain during the loading and mid-stance phases of an antalgic gait. An antalgic gait can be determined by observing the patient walk; the stance gait is shortened in relation to the swing phase, as if the patient is "favoring" one leg while walking.
Furthermore, a differential diagnosis may reveal nerve root compression -- among other possible pathologies (Starkey et al., 2010, p. 449). As both the signs and symptoms of Piriformis Syndrome closely mirror those of other lumbopelvic disorders, a secondary opinion by a physician is in order.
Works Cited
Starkey, C., Brown, S.D. & Ryan, J.L. (2010). Evaluation of orthopedic and athletic injuries
(3rd ed.). Philadelphia, PA: Davis
