Thanks for providing more information.
Sorry to hear about her pain and still undiagnosed.
As per your description,chances of Hip labral tear are less.
As her MRI is negative for herniated disc so chances of Piriformis syndrome are still present.
I want to discuss Piriformis syndrome first to give you a clear picture.
Piriformis syndrome is neuromuscular disorder that is caused when the piriformis muscle compresses the sciatic nerve causing pain, tingling and numbness in the buttocks and along the path of the sciatic nerve descending down the lower thigh and into the leg.
There is no definitive test for piriformis syndrome.
In many cases, history of trauma to the area, repetitive, vigorous activity such as long-distance walking/ running, or prolonged sitting are contributing factors.
Diagnosis of piriformis syndrome is made by the patient’s report of symptoms and by physical exam.
Because symptoms can be similar in other conditions, radiologic tests such as MRIs may be required to rule out other causes of sciatic nerve compression, such as a herniated disc, lumbar stenosis, and mass lesions in the region of the piriformis muscle.
Sometimes MRI also comes inconclusive.
As it has been seen that the muscle did not impinge directly on the nerve at the time of MRI, and the sciatic nerve seen on preoperative MRI was normal in size and signal characteristics.
This could be due to the fact that piriformis syndrome is a functional entity in which the nerve becomes compressed during prolonged sitting, walking, running, or other exercise.
It is possible that the sciatic nerve was not compromised by the piriformis muscle while the patient was lying comfortably on the MRI table.
Nerve conduction test with EMG can be helpful in her case and a clinical examination by a neurologist gives you a proper diagnosis.
I also suggest her to continue physical therapy as well.
Hope this helps.
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