Comparison of effectiveness of different surgical treatments for meralgia paresthetica

Meralgia paresthetica (MP) is a tingling, stinging or burning sensation in the anterolateral part of the thigh. It is often accompanied by varying degrees of numbness. Meralgia paresthetica is caused by a mononeuropathy of the lateral femoral cutaneous nerve (LFCN). It is commonly idiopathic, but can also have a traumatic origin, like seat belt and iatrogenic injury [1]. Usually symptoms are mild and resolve spontaneously. However, it may be severe and limit the patient in daily activities. Extension of the hip, as for example while walking or when driving a car, often exacerbates symptoms. Temporary nerve block with local anesthetic near the anterior superior iliac spine (ASIS) may relief the symptoms and is often used to confirm the diagnosis [2]. MP is the most frequent mononeuropathy of the lower limb and probably more common than recognized [3, 4]. It is often misdiagnosed, especially in children/adolescents [5]. The pure sensory symptoms in MP can be helpful in the differential diagnosis with lumbosacral radiculopathy and orthopedic conditions.
Electrophysiology and nerve block can support the diagnosis [6].

The initial treatment of MP is wait and see supported by conservative measures such as avoiding wear of tightly fitting cloths, analgetics and loss of weight by obese patients. It is reported to be successful in pain relief in about 90% of the cases [2]. If conservative treatment fails surgical treatment should be considered. The two main surgical options are neurolysis and neurectomy. In general, success rates are higher for the neurectomy procedure [7], but an obvious disadvantage is loss of sensation in the anterolateral part of the thigh. We recently reported our results for both procedures from two historical cohorts [8]. This study confirmed superior results reported in the literature for the neurectomy procedure (87.5% pain relief versus 60% after the neurolysis procedure). In addition, most patients noted not to be bothered by the numbness following the neurectomy procedure. Shortcomings of this study however are that it was conduced retrospective for two historical cohorts and that patients were not blinded for the procedure. No randomized study has been performed comparing both procedures [7]. Reason for this probably is the small number of patients that require surgery because of persistent symptoms of meralgia paresthetica. Therefore, a randomized trial can only be performed if multiple centres specialized in this type of surgery participate.

In this study protocol we will randomly and blindly compare both surgical procedures (neurolysis versus neurectomy) in patients with persistent symptoms of idiopathic meralgia paresthetica despite conservative treatment. We hypothesise a difference in outcome on pain relief in favour of the neurectomy group. Primary outcome measure will be the 7-point Likert scale (to determine perceived recovery). Secondary outcome measures will include VAS pain and Bothersomeness Index (to determine how much patients are bothered by the numbness following the neurectomy procedure) [9].

We hypothesise a difference in outcome on pain relief in favour of the neurectomy group.

6, 12, 26, 52 weeks

Neurolysis vs neurectomy