Surface anatomical landmarks for the location of posterior sacral foramina in sacral nerve stimulation.

BACKGROUND: Sacral nerve stimulation is a common treatment for various pelvic floor disorders. It consists of the percutaneous introduction of electrodes through the posterior sacral foramina for therapeutic stimulation of the target sacral spinal nerve. The aim of our study was to determine the surface anatomical landmarks of the sacrum to facilitate identification of the posterior sacral foramina. METHODS: This study was conducted on 20 human cadavers. The cadavers were placed in a prone position, and all the soft tissues of the sacral region were removed to allow exposure of the osseous structures. Different measurements were taken in relation to the posterior sacral foramina, the posterior superior iliac spine (PSIS) and the median sacral crest (MSC). A median coefficient of variation (CV) was determined. RESULTS: The diameter of the second sacral foramen showed the greatest variability. The distances between each individual foramen and the MSC had an acceptable variability (CV < 20%). In contrast, the distance between foramina had a high variability. The distance between PSIS and the second posterior sacral foramen was also found to have an acceptable variability (CV < 20%). However, the angle formed by an horizontal line between PSIS and a line between PSIS and S2 foramina had high variability. CONCLUSIONS: We found that the distance between sacral foramina and MSC is relatively constant while the distance between foramina and the relations between foramina and PSIS is highly variable. Detailed knowledge of the anatomy may facilitate electrode placement and is complementary to the regular use of fluoroscopy.

Superior cluneal nerve entrapment.

BACKGROUND AND OBJECTIVES: Pain due to superior cluneal nerve entrapment is an infrequent cause of unilateral low back pain. Here we present a case of acute unilateral low back pain treated by superior cluneal nerve (SCN) block. CASE REPORT: A 55-year-old woman presented to the outpatient clinic suffering from unilateral low back pain localized to right iliac crest and radiating to the right buttock. Her history was taken, physical examination was performed, and a thorough radiologic evaluation was performed to minimize radiculopathy and facet syndromes as causative. After transient pain relief with a diagnostic trigger point injection, entrapment of SCN was diagnosed and therapeutic nerve block with local anesthetic and steroid combination was performed. CONCLUSION: SCN is prone to entrapment where it passes through the fascia near the posterior iliac crest. Unilateral low back pain and deep tenderness radiating to the ipsilateral buttock are the clinical findings accompanying SCN entrapment. The case presented emphasizes the relief of possible SCN after limiting other etiologic causes of low back pain.

A comparison between bupivacaine instillation versus ilioinguinal/iliohypogastric nerve block for postoperative analgesia following inguinal herniorrhaphy in children.

This study compared the postoperative pain relief provided by simple instillation of bupivacaine into a hernia wound with that provided by ilioinguinal/iliohypogastric (IG/IH) nerve block. Sixty children undergoing inguinal hernia repair under general anesthesia were randomized to receive 0.25 ml/kg of 0.25% bupivacaine for either IG/IH nerve block or up to 0.5 ml/kg of the same solution for instillation nerve blocks. In the postanesthesia care unit (PACU), a trained blinded observer evaluated the patient's level of postoperative pain using a standardized 10-point objective pain scale. Fentanyl 1-2 micrograms/kg was administered intravenously to any child scoring 6 or more points on the pain scale. The difference in pain scores among the two groups were compared. The two groups were not significantly different in age, duration of surgery, or anesthesia. There was no significant difference between patients who received the two treatment modalities in their pain scores, analgesic requirements in the PACU, recovery times, and discharge times. These results demonstrate that the simple instillation of local anesthetics into a wound provides postoperative pain relief following hernia repair, which is as effective as that provided by intraoperative IG/IH nerve block.