The internal obturator muscle may cause sciatic pain

Area of Science:

• Orthopedic Surgery
• Neuroscience
• Pain Management

Background:

• Piriformis syndrome is a common cause of sciatic nerve pain.
• Diagnosis often relies on clinical examination, which can be challenging.
• Surgical intervention for piriformis syndrome targets the piriformis muscle.

Purpose of the Study:

• To investigate the intraoperative findings in patients suspected of having piriformis syndrome.
• To identify the actual source of sciatic nerve compression.
• To evaluate the efficacy of surgical intervention for internal obturator muscle-induced sciatic nerve compression.

Main Methods:

• Six patients with suspected piriformis syndrome underwent hip surgery.
• Intraoperative assessment of the piriformis muscle and sciatic nerve was performed.
• Internal obturator muscle tendon release was conducted in cases of identified compression.
• Pain scores and functional outcomes were assessed pre- and postoperatively.

Main Results:

• The piriformis muscle and tendon were found to be normal in all patients.
• Internal obturator muscle tension and sciatic nerve compression were observed in all cases.
• Postoperative median pain scores significantly decreased at 6 weeks and 3 months.
• Three patients discontinued opioid use, and two returned to work after prolonged absence.

Conclusions:

• Internal obturator muscle hypertonicity is a potential cause of sciatic nerve compression, mimicking piriformis syndrome.
• Surgical release of the internal obturator tendon can effectively alleviate sciatic nerve pain and improve function.
• This finding suggests a need to consider the internal obturator muscle in the differential diagnosis of sciatic nerve entrapment.