Anatomic Variation in Patient with Lateral Femoral Cutaneous Nerve Entrapment Neuropathy

The Association between Anatomical Variants of Musculoskeletal Structures and Nerve Compressions of the Lower Limb: A Systematic Review and Meta-Analysis

Objective: The aim of this study was to describe the main anatomical variants and morphofunctional alterations in the lower limb that compress surrounding nervous structures in the gluteal region, thigh region, and leg and foot region. Methods: We searched the Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception up to October 2023. An assurance tool for anatomical studies (AQUA) was used to evaluate methodological quality, and the Joanna Briggs Institute assessment tool for case reports was also used. Forest plots were generated to assess the prevalence of variants of the gluteal region, thigh, and leg. Results: According to the forest plot of the gluteal region, the prevalence was 0.18 (0.14-0.23), with a heterogeneity of 93.52%. For the thigh region, the forest plot presented a prevalence of 0.10 (0.03-0.17) and a heterogeneity of 91.18%. The forest plot of the leg region was based on seven studies, which presented a prevalence of 0.01 (0.01-0.01) and a heterogeneity of 96.18%. Conclusions: This review and meta-analysis showed that, in studies that analyzed nerve compressions, the prevalence was low in the thigh and leg regions, while in the gluteal region, it was slightly higher. This is mainly due to the PM region and its different variants. We believe that it is important to analyze all the variant regions defined in this study and that surgeons treating the lower limb should be attentive to these possible scenarios so that they can anticipate possible surgical situations and thus avoid surgical complications.

Ultrasonographic identification of lateral femoral cutaneous nerve anatomical variation in persistent meralgia paresthetica: A case report

BACKGROUND

Meralgia paresthetica (MP) is an entrapment mononeuropathy of the lateral femoral cutaneous nerve (LFCN). Although structural abnormalities in nerve tissues can be confirmed using ultrasonography, this is not routinely performed.

CASE SUMMARY

Herein, we present the case of a 52-year-old woman who developed MP after laparoscopic gynecological surgery. The patient was referred to our clinic from an obstetrics and gynecology clinic with symptoms of numbness and a tingling sensation in the left anterolateral thigh, which developed after surgery performed 5 mo earlier. Tests were performed to assess the disease status and determine the underlying causes. Ultrasonographic examination revealed an anatomical variation, where the left LFCN was entrapped within the inguinal ligament. This case suggests that performing ultrasonographic examination before and after surgery in the lithotomy position could help prevent MP.

CONCLUSION

This case demonstrates the value of ultrasonography in detecting anatomical variation and diagnosing persistent MP. Ultrasonography should be considered an adjunct to electromyography for optimal MP management. Further, this case would help other clinicians determine patient prognosis and decide on targeted treatment strategies.

Meralgia Paresthetica

PURPOSE OF REVIEW

This review article summaries the epidemiology, etiology, clinical presentations, and latest treatment modalities of meralgia paresthetica, including the latest data about peripheral and spinal cord stimulation therapy. Meralgia paresthetica (MP) causes burning, stinging, or numbness in the anterolateral part of the thigh, usually due to compression of the lateral femoral cutaneous nerve (LFCN).

RECENT FINDINGS

There are emerging data regarding the benefit of interventional pain procedures, including steroid injection and radiofrequency ablation, and other interventions including spinal cord and peripheral nerve stimulation reserved for refractory cases. The strength of evidence for treatment choices in meralgia paraesthetica is weak. Some observational studies are comparing local injection of corticosteroid versus surgical interventions. However, more extensive studies are needed regarding the long-term benefit of peripheral and spinal cord stimulation therapy.

Suprainguinal Re-Resection of the Lateral Femoral Cutaneous Nerve in Persistence or Recurrence of Meralgia Paresthetica After Previous Transection: Results of a Case Series

OBJECTIVE

Suprainguinal re-resection of the proximal nerve stump can be performed in case of persistent or recurrent symptoms of meralgia paresthetica after previous transection of the lateral femoral cutaneous nerve (LFCN). Currently, no long-term results for this procedure have been reported in the literature.

METHODS

In this study, 20 consecutive patients with persistent (13 cases) or recurrent (7 cases) symptoms of meralgia paresthetica were reoperated at a mean interval of 16 months after the first transection of the LFCN. The proximal nerve stump was sent for histopathologic analysis of a potential traumatic neuroma. Outcome was assessed using a 5-point Likert scale, which was obtained at a mean interval of 3.5 years after the suprainguinal re-resection.

RESULTS

The proximal stump of the LFCN was identified in 90% of the cases. Successful pain relief (Likert 1 or 2) was obtained in 65% of the patients. A neuroma was found in 11 cases (55%), mostly in recurrent cases after a pain-free interval. The indication for recurrence of symptoms more frequently resulted in successful pain relief (71%) compared with results for the indication for persistence of symptoms (62%). There was no correlation between the presence of a neuroma and the chance for pain relief.

CONCLUSIONS

Suprainguinal re-resection of the LFCN can be a successful procedure, both for persistence and recurrence of symptoms of meralgia paresthetica after previous transection, with long-lasting pain relief. Several factors, however, should be considered before performing this relatively new technique in patients that are discussed in this article.

Meralgia paresthetica attributable to surgery in the park-bench position

OBJECTIVE

Meralgia paresthetica (MP) is an entrapment neuropathy of the lateral femoral cutaneous nerve (LFCN). We report a rare MP complication after microvascular decompression (MVD) surgery in the park-bench position in a patient with hemi-facial spasm.

CASE

The patient was a 46-year-old female (height: 155 cm, weight: 42 kg). She was neither diabetic nor a regular alcohol user. After the first MVD for right hemifacial spasm, her symptom recurred and she underwent a second MVD procedure in the park-bench position that led to the disappearance of her hemifacial spasm. However, she complained of right antero-lateral thigh pain and dysesthesia without motor weakness. The symptom was limited to the LFCN area; pelvic compression test elicited a positive Tinel-like sign. Our preliminary diagnosis was MP. As conservative therapy was ineffective she underwent LFCN block 9 months after the second MVD procedure. Her symptom improved dramatically and we made a definitive diagnosis of MP. There has been no recurrence in the course of 30 months although she reported persistent mild dysesthesia in the LFCN area.

CONCLUSION

MP is a rare complication after MVD surgery in the park-bench position. Symptom abatement and a definitive early diagnosis can be obtained by LFCN blocks.