Meralgia paresthetica occurs when the lateral femoral cutaneous nerve — a nerve that supplies sensation to the surface of your outer thigh — becomes compressed, or "pinched." The lateral femoral cutaneous nerve is purely a sensory nerve and does not affect your ability to use your leg muscles.
These are the symptoms of meralgia paresthetica:
In most people, this nerve passes through the groin to the upper thigh without trouble. But in meralgia paresthetica, the lateral femoral cutaneous nerve becomes trapped — often under the inguinal ligament, which runs along your groin from your abdomen to your upper thigh.
Treatment for meralgia paresthetica focuses on relieving compression of the nerve.
Conservative measures
Conservative measures are effective for most people, with pain usually going away within a few months. They include:
If symptoms persist for more than two months or your pain is severe, treatment may include:
Surgery
Rarely, surgery is considered to decompress the nerve which means snipping the inguinal ligament. Only recommended in cases of severe and long-lasting symptoms.
After THR
It is thought that this damage to the lateral femoral cutaneous nerve can be caused by a number of issues
1. use of retracting instruments during anterior or lateral approaches
2. body weight applied on the non-operative side
3. table fitments used to support the patient on their side during lateral or posterior approaches. This could also be the use of sandbags, special pillows or other operating table attachments.
This is a popular type of support pillow. It starts off as a bean bag which is placed under the patient, then the air is suctioned out at which point it becomes solid. There are smaller pillows which, if placed incorrectly, can apply the kind of pressure being discussed.
Meralgia paresthetica after total hip arthroplasty in supine position
(medical article)
MP is a entrapment neuropathy often caused by compression of the lateral femoral cutaneous nerve (LFCN) as it travels along the posterolateral aspect of the psoas major muscle, crossing between the anterior superior iliac spine (ASIS) and the inguinal ligament, before entering the thigh. It is frequently related to iliac bone graft harvesting, but MP can occur as a transient compression neuropathy and only a few cases are reported in the literature related to prone and lateral positions during surgery. It was possibly caused by the pelvic bolster or support placed on the left side during surgery in supine position to avoid movement on the operating table.
Case Study
Meralgia Paresthetica of the Contralateral Leg After Total Hip Arthroplasty
The patient underwent THA in the right lateral position. A bean-bag positioner was used which is typically evacuated of air with suction to render it hard. Total hip arthroplasty was performed using a direct lateral approach. Intraoperative surgical time was 2.5 hours, and total anesthesia time was 3.5 hours.
A few days postoperatively, the patient began to experience “burning and shooting” pain in the non-surgical hip, but she did not report this pain until 6 weeks postoperatively. She was treated initially with a single lidocaine injection. When this proved ineffective, she was treated with topiramate (100 mg daily) and vitamin B6 (100 mg orally twice daily).
The symptoms lessened markedly at 5 months and had resolved completely at 9 months postoperatively.
These are the symptoms of meralgia paresthetica:
- Tingling and numbness in the outer (lateral) part of your thigh
- Burning pain in or on the surface of the outer part of your thigh
- Less commonly, dull pain in your groin area or across your buttocks
In most people, this nerve passes through the groin to the upper thigh without trouble. But in meralgia paresthetica, the lateral femoral cutaneous nerve becomes trapped — often under the inguinal ligament, which runs along your groin from your abdomen to your upper thigh.
Treatment for meralgia paresthetica focuses on relieving compression of the nerve.
Conservative measures
Conservative measures are effective for most people, with pain usually going away within a few months. They include:
- Wearing looser clothing
- Losing weight
- Taking OTC pain relievers such as acetaminophen (Tylenol, others) ibruprofen (Advil, Motrin, others), or aspirin.
If symptoms persist for more than two months or your pain is severe, treatment may include:
- Cortisone injections. Injections can reduce inflammation and temporarily relieve pain. Possible side effects include joint infection, nerve damage, pain and whitening of skin around the injection site.
- Antidepressants. These medications may relieve your pain. Side effects include drowsiness, dry mouth, constipation and impaired sexual functioning.
- Gabapentin (Neurontin) or pregabalin (Lyrica). These anti-seizure medications may help lessen your painful symptoms. Side effects include constipation, nausea, dizziness, drowsiness and lightheadedness.
Surgery
Rarely, surgery is considered to decompress the nerve which means snipping the inguinal ligament. Only recommended in cases of severe and long-lasting symptoms.
After THR
It is thought that this damage to the lateral femoral cutaneous nerve can be caused by a number of issues
1. use of retracting instruments during anterior or lateral approaches
2. body weight applied on the non-operative side
3. table fitments used to support the patient on their side during lateral or posterior approaches. This could also be the use of sandbags, special pillows or other operating table attachments.
This is a popular type of support pillow. It starts off as a bean bag which is placed under the patient, then the air is suctioned out at which point it becomes solid. There are smaller pillows which, if placed incorrectly, can apply the kind of pressure being discussed.
Meralgia paresthetica after total hip arthroplasty in supine position
(medical article)
MP is a entrapment neuropathy often caused by compression of the lateral femoral cutaneous nerve (LFCN) as it travels along the posterolateral aspect of the psoas major muscle, crossing between the anterior superior iliac spine (ASIS) and the inguinal ligament, before entering the thigh. It is frequently related to iliac bone graft harvesting, but MP can occur as a transient compression neuropathy and only a few cases are reported in the literature related to prone and lateral positions during surgery. It was possibly caused by the pelvic bolster or support placed on the left side during surgery in supine position to avoid movement on the operating table.
Case Study
Meralgia Paresthetica of the Contralateral Leg After Total Hip Arthroplasty
The patient underwent THA in the right lateral position. A bean-bag positioner was used which is typically evacuated of air with suction to render it hard. Total hip arthroplasty was performed using a direct lateral approach. Intraoperative surgical time was 2.5 hours, and total anesthesia time was 3.5 hours.
A few days postoperatively, the patient began to experience “burning and shooting” pain in the non-surgical hip, but she did not report this pain until 6 weeks postoperatively. She was treated initially with a single lidocaine injection. When this proved ineffective, she was treated with topiramate (100 mg daily) and vitamin B6 (100 mg orally twice daily).
The symptoms lessened markedly at 5 months and had resolved completely at 9 months postoperatively.