Sciatic Nerve Variants in Patients Diagnosed With Sciatica: Is There a Correlation?

PURPOSE: Compression of the sciatic nerve in its path along the piriformis muscle can produce sciatica-like symptoms. There are 6 predominant types of sciatic nerve variations with type 1 being the most common (84.2%), followed by type 2 (13.9%). However, there is scarce literature on the prevalence of sciatic nerve variation in those diagnosed with sciatica. MATERIALS AND METHODS: The charts of 95 patients clinically diagnosed with sciatica who had a magnetic resonance imaging of the pelvis/hip were retrospectively studied. All patients had T1-weighted axial, coronal, and sagittal images. Magnetic resonance imagings were interpreted separately by 2 board-certified fellowship-trained musculoskeletal radiologists to identify the sciatic nerve variant. RESULTS: Seven cases were excluded because of inadequate imaging. Of the remaining 88 patients, 5 had bilateral sciatica resulting in a sample size of 93 limbs. Fifty-two (55.9%) had type 1 sciatic nerve anatomy, 39 (41.9%) had type 2, and 2 (2.2%) had type 3. The proportions of type 1 and 2 variations were significantly different from the normal distribution (P < 0.001), whereas type 3, 4, 5, and 6 variants were not (P = 1.00). CONCLUSIONS: There is strong statistical significance regarding the relationship between sciatic nerve variation and the clinical diagnosis of sciatica. Preoperative magnetic resonance imaging can be considered in sciatica patients to prevent iatrogenic injury in pelvic surgery.

Perisciatic Ultrasound-Guided Infiltration for Treatment of Deep Gluteal Syndrome: Description of Technique and Preliminary Results.

The objective of this study was to describe a perisciatic ultrasound-guided infiltration technique for treatment of deep gluteal syndrome and to report its preliminary clinical results. A mixture of saline (20 mL), a local anesthetic (4 mL), and a corticosteroid solution (1 mL) was infiltrated in the perisciatic region between the gluteus maximus and pelvitrochanteric muscles. Relative pain relief was achieved in 73.7% of the patients, with average preprocedural and postprocedural visual analog scale scores of 8.3 and 2.8, respectively. Fifty percent of patients reported recurrence of discomfort, and the average duration of the therapeutic effect in these patients was 5.3 weeks.

[Proposition of an anatomic and functional reserve into the spinal canal, as an interference factor on the mechanical degenerative low back pain and sciatica physiopathology]. / Proposição de uma reserva anatomofunctional, no canal raquidiano, como fator interferente na fisiopatologia das lombalgias e lombociatalgias mecânico-degenerativas.

OBJECTIVE: To test the hypothesis of an anatomic and functional reserve in the spinal canal that explains the radiological changes in lumbar spine of asymptomatic individuals, the differences in modalities of clinical presentation and the discrepancies in the prevalence of mechanical and degenerative low back pain and sciaticas. CASES AND METHODS: Two groups of 27 persons were submitted to computed axial tomography. In one group, the patients presented low back pain and/or sciaticas. The other formed by matched controls, showed no signs or symptoms. The bony canal area, dural sac area, interfacets distance and lateral recesses depth were quantitative assessed. RESULTS: The asymptomatics ones had larger bony canals than the acute and chronic patients, due to statistical significant differences. The ranges responsible for these differences and whose averages had higher figures in the asymptomatics ones in relation to the chronic patients, were the bony canal areas at L3-L4, L4-L5, the dural sac area and lateral recesses depth at L4-L5; in relation to acute ones: the bony canal areas at L3-L4, L4-L5, L5-S1, dural sac area at L4-L5, L5-S1, and sagittal diameter L5-S1 and lateral recesses depth at L4-L5. CONCLUSIONS: The radiological changes in asymptomatic ones, the lack of symptoms in the control group, the presence of chronic and acute features and the discrepancies in the prevalence of low back pain were attributed to the existence of an anatomic and functional reserve. This reserve would be determined by the presence of a "safety factor" which would have differential distribution in asymptomatics, acute and chronic. It would be the element able to influence the presence or absence of low back pain in persons with radiological changes.

Giant sacral schwannoma. A case report.

STUDY DESIGN: Case report. OBJECTIVES: To present a rare case of a previously operated giant schwannoma located in the sacrum, and to make some considerations regarding diagnostic modalities and treatment options. SUMMARY OF BACKGROUND DATA: Large sacral schwannomas with anterior cortex erosion and associated intrapelvic extension are uncommon. Only a few case reports and small series have been published. There is no established consensus regarding diagnostic modalities, necessity for histologic diagnosis before surgery, or best surgical option. METHODS: The patient presented with a 2-month history of right sciatica and severe low back pain. After a histopathologic diagnosis and a complete set of image studies, the resection of the tumoral mass was planned posteriorly. RESULTS: Seventeen months after tumor resection, the patient has a good clinical outcome, and there are no radiologic signs of instability or recurrence. CONCLUSIONS: Considering the experience of the few cases reported in the world literature, the management of this tumor appears to grant favorable results, recurrence being the most frequent complication.