BACKGROUND: Tethered cord syndrome (TCS) is an increasingly recognized clinical condition, with untethering surgery considered the classically effective treatment. Yet, as evidence has aggregated, the surgical outcomes of untethering remain controversial. This study aimed to systematically evaluate the clinical outcomes in patients who underwent primary or revision untethering.
METHODS: This retrospective study was conducted at the Department of Spine Surgery of Changzheng Hospital between January and December 2016. Patients with TCS who underwent untethering surgery were recruited for the study. Information collected included demographic data, main clinical manifestations, and outcomes after untethering surgery.
RESULTS: A total of 112 patients (60 males and 52 females) were included in this study, with mean follow-up of 13.7 years. The surgical outcomes of the primary untethering varied among symptoms, with remission rates of 30.0% for pain, 24.4% for paresthesia, 18.6% for motor deficit, 12.6% for bladder dysfunction, and 21.2% for bowel dysfunction. Moreover, 23.3%-40.2% of patients suffered deterioration after surgery during the follow-up period. Twenty-eight patients underwent revision untethering surgery. In these patients, the remission rate decreased by 5.6%-16.7% compared with the primary operation. Moreover, most patients (58.8%-70.6%) experienced no benefits after revision surgery.
CONCLUSIONS: With a possible high risk of recurrence, further exploration of the indications and timing of the untethering surgery is needed. Conservative treatment and omnidirectional care might be a better choice for patients with retethering with recurrent symptoms.

OBJECTIVE: To evaluate the accuracy of oblique view extended imaging (OVEI) in locating the position of the fetal conus medullaris.
METHODS: One hundred and twenty-two normal fetuses and five counterparts with spinal bifida received prenatal ultrasound examination. The vertebral body at the terminal of the conus medullaris and the coronal section of over five vertebral bodies were reconstructed using OVEI. Development of the nervous system of normal fetuses was assessed at postnatal day 28. For spinal bifida cases, pathological examination was performed.
RESULTS: Among 127 fetuses, the conus medullaris was accurately positioned in 120 (94.0%) cases according to OVEI. OVEI failed to locate the conus medullaris in three healthy fetuses due to obesity of the mother and four cases with spinal bifida due to abnormal fetal position. The conus medullaris was located at L3 or above in 115 healthy fetuses. The conus medullaris was positioned below L4 in five fetuses with spinal bifida, including L5 in two, S1 in two, and S3 in one, which was consistent with the findings of pathological examination.
CONCLUSIONS: OVEI can display the 12th rib, T12, and conus medullaris simultaneously. OVEI is applicable to precisely locate the position of the conus medullaris and useful for prenatal evaluation of spinal bifida.